Othorn - HT capable?

[m_ms]

Hi there,

First post. 

I'm thinking of getting the Othorn build for my 2-channel setup. My main speakers are the all-horn Simon Mears Audio Uccello's, and they're augmented downwards with a single SVS SB16-Ultra. Low-pass is 62Hz, and I'm running the mains without a high-pass - that is, full range. My listening room is some 1,900 cu ft with concrete walls and hardwood floor, and the SVS is placed between my main speakers (see picture). 

My setup is for both music and HT (I have a 127" fixed frame screen), but my main priority is getting the integration between the mains and sub(s) right. The SB16-Ultra is no slouch for its size and integrates fairly well my main horn speakers, not least due to a friend of mine who's got great ears and is just brilliant at fine tuning and integrating subs and setups as a whole. That said it is still evident that the SVS speaks with a slightly different voice than my main speakers, and I'm therefore pondering the implementation of a horn sub. The question is though: which shall it be?

From what I've read of the Othorn it makes great bass within its specific frequency range, and I'm thinking it may be a shoe-in with my main horns. It's a 28Hz horn though, and that begs the question whether it'll fill in sufficiently and go deep enough for HT-use? Different individuals different needs; in my case I find the SVS very capable and satisfying with regards to bass depth, and I'm assuming it'll sail past the Othorn in this regard - am I right? On the other hand the Othorn will likely spank the SVS from 25Hz and up - where most material resides.

Then there's the Gjallarhorn,  which is obviously a deep-bass monster, but I suspect the ringing modes past some 60Hz may prove it to be less viable for a music setup - even with a 60-65Hz low-pass? It's also big and heavy, and being that I/we live in a 2nd floor apartment, well, try and imagine getting a Baltic Birch iteration up those stairs. I quiver at the thought..

I've also conversed with lilmike over at the AVS Forum, who's a most helpful and kind individual with alternative solutions such as the MicroWrecker and others of his creations.

Please chime in on the Othorn in particularly, and also whether it can be used with the B&C 21DS115 unit (instead of the sibling 21WS152).  

 

/Mikael

 

[Kvalsvoll]

I can not help you with the Othorn, but when I read "apartment" I am curious to learn how your neighbors cope, of course it is possible you only listen at moderate levels, but most people with capable systems tend to actually use it..

And those horns look great, by the way.

[m_ms]

35 minutes ago, Kvalsvoll said:

I can not help you with the Othorn, but when I read "apartment" I am curious to learn how your neighbors cope, of course it is possible you only listen at moderate levels, but most people with capable systems tend to actually use it..

And those horns look great, by the way.

Thanks - I'm indeed dearly fond of my main horn speakers  

Good question re: my neighbors. I've asked them to their face more than once and know them well enough that they're giving me a straight answer, and they've never been bothered by my listening to music or watching films (with the sub in the mix, so to speak). Part of the reason is how they have arranged their apartments, and that none of the rooms they use frequently or at evening/night time are directly above or below my listening room. Sound isolation must be a factor also for we're never bothered by their doings, apart from the ones living above us and that their walking about is clearly felt/heard (which is still no bother, but simply a condition of living in an apartment). 

Normally my music listening level is relatively moderate, usually somewhere between 65-80dB's, and with the occasional "bursts" beyond that. Watching Blu-ray's at my normal reference level is difficult to assess in average dB's given the wide dynamic range here, but I guess the level can span anywhere between an average 70-80's with peaks at 100+ dB's. 

Why then the Othorn? Because I take it it sounds great at more sane levels as well - indeed that's one of my main areas of concern or investment, to have the sound come alive and be fairly visceral at more "reasonable" levels, and for this to happen I've found horn speakers, not least all-horns, to be indispensable; the larger and more efficient the better. Truly I'm done with most any direct radiating solution..

[Ricci]

The Othorn really operates best with the 21SW152-4, but the 21DS115-4 could work. In an apartment at those relatively low levels it could probably get down to 20Hz with a bit of EQ but it really is designed as a 25Hz and up sub. Even though the SB16 is a decent sealed sub that can technically go way lower than the Othorn it is not going to have greater headroom until below 20Hz. These are completely different sub designs with much different goals. The Othorn has so much more headroom I can't see how you would possibly use even 10% of it in an apartment. It should sound great operating at such a relaxed output level though. As an alternative you could do a Skhorn or a half of one, which can go lower than the Othorn depending on vent config and would be slightly smaller.

Have you thought about doing a vented subwoofer with a 18 or 21" pro style driver that is bigger than the SB16 but not quite so big or heavy as the Othorn? It should still have plenty of extra headroom for your needs and be much higher efficiency to match your mains. 

[Kvalsvoll]

If you plan to cross at 60-80hz, the alternative suggested by @Ricci could be a good alternative - a ported box. Use a pro driver, port it very low, choose a smaller driver for smaller cabinet size.

For very low frequencies the size of the radiating surface does not matter so much, so the ported would give you much of the benefits of a horn, in a smaller cabinet, and much easier to build.

[m_ms]

2 hours ago, Ricci said:

The Othorn really operates best with the 21SW152-4, but the 21DS115-4 could work. In an apartment at those relatively low levels it could probably get down to 20Hz with a bit of EQ but it really is designed as a 25Hz and up sub. Even though the SB16 is a decent sealed sub that can technically go way lower than the Othorn it is not going to have greater headroom until below 20Hz. These are completely different sub designs with much different goals. The Othorn has so much more headroom I can't see how you would possibly use even 10% of it in an apartment. It should sound great operating at such a relaxed output level though. As an alternative you could do a Skhorn or a half of one, which can go lower than the Othorn depending on vent config and would be slightly smaller.

Have you thought about doing a vented subwoofer with a 18 or 21" pro style driver that is bigger than the SB16 but not quite so big or heavy as the Othorn? It should still have plenty of extra headroom for your needs and be much higher efficiency to match your mains. 

Thanks for the reply, Ricci. 

I've only briefly, and not very recently considered vented sub solutions, and that in fact only with larger pro-style woofers. For some reason though I keep avoiding vented subs as a more general stance, although it may simply be weird conjecture on my part. What I do think on the matter of vented subs is that they're a less than ideal match with my main speakers for introducing an out-of-phase port contribution (perhaps a TH is doing a similar-ish thing with the output from the backside of the driver in the horn mouth?), and integration with the mains is very important to me. Do you have a particular vented sub solution in mind, preferably with a 21" pro style driver?

I know, for all intends and purposes the Othorn is huge overkill for my needs, but that's also part of the rationale; to go after the biggest headroom via high efficiency, overall power handling and large air radiation area - and not least have a horn augment another horn. I'm looking for that totally effortless and relaxed bass imprinting to complement my main horns, but there will of course be a price to pay when achieving high efficiency from a relative compact (tapped-)horn enclosure, and that's the 15-25Hz area where the Ghorn seems to be the Maestro. However, the thought of having the Othorn perform rather admirably from some 20-25Hz and up, and sounding great at that, is indeed very beguiling - size and weight be damned.

And with regard to the chosen driver for the Othorn, thanks for pointing out the 21WS152-4 as the preferred match here. I was trying to save a few coins with the less expensive sibling model, but I guess it would defeat the purpose not going all-out and have the driver that fits the best.

I've actually never considered the Skhorn (but certainly read of it), let alone half of it - what does that entail? I'm intrigued. 

[m_ms]

9 minutes ago, Kvalsvoll said:

If you plan to cross at 60-80hz, the alternative suggested by @Ricci could be a good alternative - a ported box. Use a pro driver, port it very low, choose a smaller driver for smaller cabinet size.

For very low frequencies the size of the radiating surface does not matter so much, so the ported would give you much of the benefits of a horn, in a smaller cabinet, and much easier to build.

Hmm, another recommendation for a vented solution. Thanks, Kvalsvoll, I'll keep it in mind, but I'm not that enthused about the thought of a vented sub in my setup, although I'll gladly stand corrected if there's a treat in the wait here.

Somehow though it's an either/or for me; if not a seriously capable overkill horn sub I'd rather "trot along" with the SB16. Really, for what it is and in light of its size the SB16 is rather powerful and quite "musical," and it digs deep. As commercial subs go it's a handy plug-and-play solution, though heavy as hell with its smaller dimensions and gloss finish at some 122Ibs.

 Oh well, if they're any particular DIY vented sub solutions that comes to your mind with large pro drivers, please enlighten me. 

[SME]

2 hours ago, m_ms said:

Hmm, another recommendation for a vented solution. Thanks, Kvalsvoll, I'll keep it in mind, but I'm not that enthused about the thought of a vented sub in my setup, although I'll gladly stand corrected if there's a treat in the wait here.

It's not clear what you are looking for. 

12 hours ago, m_ms said:

My setup is for both music and HT (I have a 127" fixed frame screen), but my main priority is getting the integration between the mains and sub(s) right. The SB16-Ultra is no slouch for its size and integrates fairly well my main horn speakers, not least due to a friend of mine who's got great ears and is just brilliant at fine tuning and integrating subs and setups as a whole. That said it is still evident that the SVS speaks with a slightly different voice than my main speakers, and I'm therefore pondering the implementation of a horn sub. The question is though: which shall it be?

Can you be more specific here?  Are you hearing this different voice at low levels?  Or only when the sub is pushed?  If you think you are hearing your subwoofer independently from your mains, there could be a number of issues, which a different sub may or may not solve.  You could be hearing the effects of room resonances, which are likely strong in your concrete wall room) and which can be attenuated using EQ.  Another possibility is that the XO is not matched as well as you believe it to be.  Still another possibility is that the mains are straining because of the lack of high pass filter.

It's certainly possible that the sub is producing enough distortion at low levels for you to hear, in which case, a better quality sub would definitely help.  And a better sub would give you more headroom for when you want to crank things or for dynamic movie sounds.  If you do opt to build another sub, I agree with the others here that a ported design using a pro-style woofer is the best choice, unless you are very space constrained and/or willing to spend a lot of money on amps and multiples.  Among the horns discussed, the Gjallarhorn will likely be hard to integrate because of the narrow crossover region.  The Othorn lacks extension for movies, and any EQ used to boost the extension will dramatically reduce its headroom, making it a big waste of space.  The Skhorn would be the only one I'd recommend at all, and it is effectively a *ported* sub for low frequencies.

So by far your best bet is probably a ported sub with a good pro driver.  For low frequencies, it will have a lot more headroom and a lot less distortion than the SVS.  For high frequencies, it will behave similar to the SVS but with less distortion, more headroom, and better upper end extension to improve integration with the mains.  If you're under the impression that ported subs have inferior sound, I recommend reconsidering that conclusion.  For a ported sub tuned to 20 Hz or below, the musical part of the spectrum (i.e. 40 Hz and above) will sound essentially identical to a sealed sub except a bit louder and cleaner.  What's not to like?

[maxmercy]

Build two of lilmike's F20s (well braced) to get the lowpassed horn sound it seems you desire.  If that isn't enough, build two more.  A direct radiator or direct radiator + vent will sound different than a front loaded horn, and a tapped horn will sound different than a front-loaded horn where the driver is buried and not near the mouth.  My guess is you will like the front loaded horn from the posts above.  The F20 will do well.  If you need more extension, in the same cabinet volume, look at tapped horns or a hybrid design like the SKHorn.  

Front loaded folded horns will sound like they have 'cleaner' bass due to the lowpass effect the cabinets have.  Only multiple sealed or vented cabs can duplicate it, and even then, not exactly.

JSS

[m_ms]

7 hours ago, SME said:

It's not clear what you are looking for. 

Can you be more specific here?  Are you hearing this different voice at low levels?  Or only when the sub is pushed?  If you think you are hearing your subwoofer independently from your mains, there could be a number of issues, which a different sub may or may not solve.  You could be hearing the effects of room resonances, which are likely strong in your concrete wall room) and which can be attenuated using EQ.  Another possibility is that the XO is not matched as well as you believe it to be.  Still another possibility is that the mains are straining because of the lack of high pass filter.

It's certainly possible that the sub is producing enough distortion at low levels for you to hear, in which case, a better quality sub would definitely help.  And a better sub would give you more headroom for when you want to crank things or for dynamic movie sounds.  If you do opt to build another sub, I agree with the others here that a ported design using a pro-style woofer is the best choice, unless you are very space constrained and/or willing to spend a lot of money on amps and multiples.  Among the horns discussed, the Gjallarhorn will likely be hard to integrate because of the narrow crossover region.  The Othorn lacks extension for movies, and any EQ used to boost the extension will dramatically reduce its headroom, making it a big waste of space.  The Skhorn would be the only one I'd recommend at all, and it is effectively a *ported* sub for low frequencies.

So by far your best bet is probably a ported sub with a good pro driver.  For low frequencies, it will have a lot more headroom and a lot less distortion than the SVS.  For high frequencies, it will behave similar to the SVS but with less distortion, more headroom, and better upper end extension to improve integration with the mains.  If you're under the impression that ported subs have inferior sound, I recommend reconsidering that conclusion.  For a ported sub tuned to 20 Hz or below, the musical part of the spectrum (i.e. 40 Hz and above) will sound essentially identical to a sealed sub except a bit louder and cleaner.  What's not to like?

Thanks for chiming in, SME, with some interesting observations. 

Broadly put, I don't want a vented sub to sound like a (typical) vented sub, so in that regard it's clear what I don't look for in a sub sound-wise. My main all-horn speakers (and that's important to point out, that they're all-horn) are sharp as a tack and with very little smear in the mid-upper bass they cover, and I'm simply not going to wrestle with a vented sub solution that goes in the opposite direction. They may not all do so, and if not I haven't heard them. My way though of giving a future vented sub the benefit of the doubt is more a reflection of a relatively limited experience with vented solutions rather than being in the blind of what I want.

There's a scent here, if I'm not wrong, that it's not the bass principle that matters - i.e.: whether it's sealed, ported, OB, horn, tapped horn, etc. - but instead the integration and implementation of a sub(s), and one which will further render the specific bass principle a theoretical distinction rather than one of any practical concern. I can't vouch for that per my own experience, but your observation on port tuning at or below 20Hz to make for an almost sealed sound and the use of pro drivers (as recommended by Ricci) has me slightly intrigued here. I'm certainly much more inclined towards the use of a pair of vented and efficient pro driver subs (preferably 18"+) than a more hifi-ish multiples approach. If there options here (on the former) that comes naturally to your mind, let me know.

Regarding my SB16 and its "different voice" it appears it has nothing to do with it sounding disjointed or being poorly integrated as such, and its audible effect seems independent of SPL. I find it hard to believe the SB16, in my setup and use at least, is really ever strained to produce distortion that's actually audible, so whatever pulls it in a different direction compared to my mains must be something inherent to the driver specs and construction in combination with the chosen enclosure size/amp/DSP.

The sound of the SB16 is very solid, rather tight, weighty and non-resonant, but slightly "contained" as if holding back a bit, and when let loose can be quite thunderous and explosive. If anything its nature shifts from more moderate levels to elevated dittos to a more freed presentation as if being let loose from a harness, in a sense. Through any SPL there's the sensation, and this is purely guessing, that it takes some juice to get the driver going, and it produces a slight thickening/reticence to the (edge of the) bass and the lower registers of voices for example. I also find the SB16 could do a bit better in the roughly 35-65Hz range in being more "energetic" here. And I can say with absolute certainty that my mains aren't strained. They sport a (measured) 105dB's sensitivity and can go excessively loud while being very cool. I don't high-pass them because I find it better to let them run full-range than running them through a filter that likely does more than merely high-pass - i.e.: unless I have the financial means to go all-in here it's moot. 

Your rundown on the Ghorn and Othorn makes sense. They both cover a range just outside of what I'd want them to - that is, the Othorn may be slightly lacking in the (U)LF department and the Ghorn, as your point out, seems less than ideal in its upper operating range towards the cross-over. That said I'd be more willing to sacrifice ULF (the Ghorn) than proper integration (Othorn). And with regard to the Skhorn that's certainly an option I'll look more into, though it would have to be the "halved" solution.

[m_ms]

7 hours ago, maxmercy said:

 Build two of lilmike's F20s (well braced) to get the lowpassed horn sound it seems you desire.  If that isn't enough, build two more.  A direct radiator or direct radiator + vent will sound different than a front loaded horn, and a tapped horn will sound different than a front-loaded horn where the driver is buried and not near the mouth.  My guess is you will like the front loaded horn from the posts above.  The F20 will do well.  If you need more extension, in the same cabinet volume, look at tapped horns or a hybrid design like the SKHorn.  

Front loaded folded horns will sound like they have 'cleaner' bass due to the lowpass effect the cabinets have.  Only multiple sealed or vented cabs can duplicate it, and even then, not exactly.

JSS

maxmercy --

The dual F20 solution of lilmike is among the front-runners of mine, so thanks for pointing to them. I'm glad you acknowledge the difference in perceived bass between the different solutions - something I believe is lacking - and also for trying to assess my preference through above posts.

Have you ever heard the Othorn, and if so how would you compare it to the F20? I take it you have experience with the latter, and if so how would you describe its bass compared to typical sealed, or direct radiating subs in general? Initially I looked into the THT, but the cheaper build of the F20 made me abandon it, although I'm sure it's quality bass horn as well. The F20 is a some ~20Hz horn, right? That would have it extend somewhat deeper than the Othorn, I presume, and be indeed very worthwhile for HT-duties as well. 

I'll have to look more into the Skhorn..

[maxmercy]

F20 and THT are very similar.  THT is tuned higher (~25Hz), and is a little smaller.  Lilmike and I fired up his first F20 build IIRC, and it is capable, but it does need the extra bracing, the first one was not extensively braced if memory serves right, and 1 or 2 outer panels were moving with content.  I have not heard the Othorn, though.  Tapped horns will generally give you more higher order harmonics due to the position of the driver cone.  Running sweeps through sealed and resonant systems does reveal some differences, but after signal shaping, and driven at reasonable levels, the differences get smaller and smaller.  Turning up the SPL will make the differences more audible.

Ricci is probably one of the most experienced people on earth regarding what differing subwoofer systems sound like with high power sweeps and the differences between them.  

If you have multiple sealed systems, they can sound very much like a horn, it is just that you need more of them, b/c in a horn, excursion is kept low through the operating band.  You need multiple sealed units to accomplish the same SPL as a horn with similar low excursion levels.  

F20s are big, but not that big, and on their sides may fit under your mains well, and can be finished in a similar fashion.  They are not that hard to build, and the drivers for them are not budget breakers, but all of the designs you have listed were carefully designed and if well implemented and integrated, should do very well for your goals.

JSS

[SME]

7 hours ago, m_ms said:

Thanks for chiming in, SME, with some interesting observations. 

Broadly put, I don't want a vented sub to sound like a (typical) vented sub, so in that regard it's clear what I don't look for in a sub sound-wise. My main all-horn speakers (and that's important to point out, that they're all-horn) are sharp as a tack and with very little smear in the mid-upper bass they cover, and I'm simply not going to wrestle with a vented sub solution that goes in the opposite direction. They may not all do so, and if not I haven't heard them. My way though of giving a future vented sub the benefit of the doubt is more a reflection of a relatively limited experience with vented solutions rather than being in the blind of what I want.

There's a scent here, if I'm not wrong, that it's not the bass principle that matters - i.e.: whether it's sealed, ported, OB, horn, tapped horn, etc. - but instead the integration and implementation of a sub(s), and one which will further render the specific bass principle a theoretical distinction rather than one of any practical concern. I can't vouch for that per my own experience, but your observation on port tuning at or below 20Hz to make for an almost sealed sound and the use of pro drivers (as recommended by Ricci) has me slightly intrigued here. I'm certainly much more inclined towards the use of a pair of vented and efficient pro driver subs (preferably 18"+) than a more hifi-ish multiples approach. If there options here (on the former) that comes naturally to your mind, let me know.

This is more or less correct.  Each type has its pros and cons, and the end result depends on many other factors.  It's possible to build a sealed sub that is sloppier sounding than a vented sub.  A poorly designed horn or even a good horn that's used outside its ideal range can exhibit more noise and distortion than a better implemented sealed or ported sub.  Among these, choice of driver is also a substantial factor.  And last but definitely not least, the effects of room acoustics and placements on bass are substantial in small rooms.

The relative benefits of sub horns are more apparent when used in large rooms and  outdoors where greater output is needed and distortion is more audible.  Indoors, room acoustic effects are much stronger.  The room acoustics tend to provide low frequency boost, potentially reducing need for output down low and reducing audibility of distortion.  On the other hand, small rooms benefit from multiple subs placed at different locations, and these benefits can extend to frequencies above the traditional sub range in a well-designed system.  For this reason, I believe horns are less attractive for small rooms because of their (typically) large unit size and more limited upper end bandwidth.  That doesn't mean that they aren't a good choice, but the justification is weaker than for large rooms and outdoor spaces.

9 hours ago, m_ms said:

Regarding my SB16 and its "different voice" it appears it has nothing to do with it sounding disjointed or being poorly integrated as such, and its audible effect seems independent of SPL. I find it hard to believe the SB16, in my setup and use at least, is really ever strained to produce distortion that's actually audible, so whatever pulls it in a different direction compared to my mains must be something inherent to the driver specs and construction in combination with the chosen enclosure size/amp/DSP.

All speakers and subs have some baseline noise and distortion that are present even at low levels.  However, it's a matter of debate how audible these things are.  Some people claim to be able to hear a difference, but I do have my doubts.  I find that *linear response* (i.e. frequency + phase response alone) including room effects and involving the full musical bandwidth has such a strong impact on perception that it's very hard to reliably judge the non-linear aspects (noise, distortion, and dynamic compression) of  the sound.  I will admit that I myself have had the impression of hearing cleaner sound from my subs as I have upgraded them, but given my experiences with linear response,  I have to second guess myself.

The exception to this may be in outdoor environments.  As @Ricci can attest to, the lack of acoustic effects including room gain together with use of pure tone sine sweeps reveals a lot about the sound that may not be noticed inside a room with "normal" content.

9 hours ago, m_ms said:

The sound of the SB16 is very solid, rather tight, weighty and non-resonant, but slightly "contained" as if holding back a bit, and when let loose can be quite thunderous and explosive. If anything its nature shifts from more moderate levels to elevated dittos to a more freed presentation as if being let loose from a harness, in a sense. Through any SPL there's the sensation, and this is purely guessing, that it takes some juice to get the driver going, and it produces a slight thickening/reticence to the (edge of the) bass and the lower registers of voices for example. I also find the SB16 could do a bit better in the roughly 35-65Hz range in being more "energetic" here. And I can say with absolute certainty that my mains aren't strained. They sport a (measured) 105dB's sensitivity and can go excessively loud while being very cool. I don't high-pass them because I find it better to let them run full-range than running them through a filter that likely does more than merely high-pass - i.e.: unless I have the financial means to go all-in here it's moot.

Please allow me to point out a few things.

First and foremost, sub-bass is almost always accompanied by higher frequencies, which have a major impact on the perception of that sound.  In fact, without higher frequencies, sub bass cannot start or stop.  The transient response of sub bass has everything to do with higher frequencies.  Try listening to the sub play with the amps to the mains turned off and note that it's not tight at all.  So if you perceive a lack of "energy" in the 35-65 Hz range, it could be that you are perceiving poor transient response for notes whose fundamental fall in that range, which could involve not just those frequencies but also frequencies up to a few octaves above.

Second, the vast majority of vocal content exists above the sub range.  In principle, the fundamental frequency of the lowest bass vocalists reaches down to around 60 Hz, but even then, almost all the content involves higher frequencies.  Most vocal recordings are high-pass filtered somewhere around 100 Hz or even higher.  (A lot of mic pre-amps have a switch to engage such a filter.)  With an XO of 60 Hz, very little vocal sound should be coming from the sub at all.

None of this is to say that your mains are in any way the cause of the problem, though without quality anechoic measurements, it's hard to say for certain.  Nevertheless, room effects are likely very strong in your case, especially being that you have concrete walls, and it is important to consider them in conjunction with the speakers and subs.  Two kinds of room issues may be involved.  First and most important are room resonances, which are peaks in the response at certain frequencies.  For example, in the 35-65 Hz range, it is very likely that you have one or more strong room resonances.  You probably have some above that range also.  These can have a substantial adverse impact on the sound regardless of what the subs and speakers are capable of.  Room resonances can be addressed by moving the sub or listener, by using additional subs in other locations, or by using EQ to attenuate them.  Room measurement capability is very helpful to identifying problematic resonances and confirming their reduction after applying one or more solutions.

The second potential room issue involves interference causing a suck-out, particularly from the wall behind your speakers.  Being large horns, your speakers are much more resistant to this type of problem than most, but depending on their characteristics including their depth and distance from the wall, they may still exhibit a suck-out down low, for example in the 70-120 Hz range, which is responsible for a lot of bass power and loudness of frequencies an octave below and certainly could influence perception of the lower registers of some vocals.  Unfortunately, the suck-out may be harder to fix.  Moving the speakers will change the affected frequencies, and putting more distance between the speakers and wall will help overall.  Adding fairly thick absorption on the wall behind the speakers (ideally 6" or more, depending on material) can also help quite a bit.

In either case, measurement capability is key to identifying and correcting problems.  It is indispensable.  It can also help you improve the integration between the mains and subs.  With all that said, it's probably still to your benefit to upgrade your SVS sub for those times you like to watch movies or turn music up higher than "65-80 dB".  The key question is what suits you best, and that depends on a lot of things.  I think getting a handle on what your room is doing is a good starting point, especially if you are tempted to get horns.  If you find that you have a lot of room problems above the 60-65 Hz crossover, you might want a sub that can cleanly play higher.

To your last point about your mains not being strained, by running full-range:  Technically you are correct, at least in so far as you aren't pushing them to their limits.  However even if not strained, the baseline distortion from frequencies below the 60-65 Hz limit of the horn will be greatly amplified by the horn.  A high pass filter may still be desired here, especially for movies which can have some pretty hot low frequency content.  The downside to using a high pass filter on the mains is that it may make integration with the sub more difficult.

[lilmike]

9 hours ago, maxmercy said:

F20 and THT are very similar.  THT is tuned higher (~25Hz), and is a little smaller.  Lilmike and I fired up his first F20 build IIRC, and it is capable, but it does need the extra bracing, the first one was not extensively braced if memory serves right, and 1 or 2 outer panels were moving with content.  I have not heard the Othorn, though.  Tapped horns will generally give you more higher order harmonics due to the position of the driver cone.  Running sweeps through sealed and resonant systems does reveal some differences, but after signal shaping, and driven at reasonable levels, the differences get smaller and smaller.  Turning up the SPL will make the differences more audible.

Ricci is probably one of the most experienced people on earth regarding what differing subwoofer systems sound like with high power sweeps and the differences between them.  

If you have multiple sealed systems, they can sound very much like a horn, it is just that you need more of them, b/c in a horn, excursion is kept low through the operating band.  You need multiple sealed units to accomplish the same SPL as a horn with similar low excursion levels.  

F20s are big, but not that big, and on their sides may fit under your mains well, and can be finished in a similar fashion.  They are not that hard to build, and the drivers for them are not budget breakers, but all of the designs you have listed were carefully designed and if well implemented and integrated, should do very well for your goals.

JSS

Yes, that was the original build. Completely unbraced, but I did use decent 3/4" plywood. In hindsight, it would have benefited from some bracing. 

One thing to note - when turning up tapped horns, it has been my experience that the response flattens out as they approach war volume. Of course, war volume SPLs in an apartment might make for war with the neighbors. 

[Kvalsvoll]

On 4/11/2018 at 11:34 AM, m_ms said:

...

There's a scent here, if I'm not wrong, that it's not the bass principle that matters - i.e.: whether it's sealed, ported, OB, horn, tapped horn, etc. - but instead the integration and implementation of a sub(s), and one which will further render the specific bass principle a theoretical distinction rather than one of any practical concern.

...

Regarding my SB16 and its "different voice" it appears it has nothing to do with it sounding disjointed or being poorly integrated as such, and its audible effect seems independent of SPL. I find it hard to believe the SB16, in my setup and use at least, is really ever strained to produce distortion that's actually audible, so whatever pulls it in a different direction compared to my mains must be something inherent to the driver specs and construction in combination with the chosen enclosure size/amp/DSP.

The sound of the SB16 is very solid, rather tight, weighty and non-resonant,

...

The typical consumer subwoofer will never deliver a sound character similar to what you experience with your horns. But that does not make it useless, it fills in the deep bass below where the horns roll off, and for a lot of music most of the bass is reproduced from the horns.

From what you write it looks like you have identified this difference in sound, and now start to wonder if it is possible to achieve a sound more similar to the horns at lower frequencies. And it is possible. But of course the lower bass will by nature sound different and give a different experience compared to the upper bass range, where most of the attack and kick is.

One way to achieve this is to build something yourself, use a pro driver with limited excursion and high BL, place it in a ported cabinet that is too large and ported too low.

[Ricci]

Vented boxes can have problems that have resulted in a common preconception of what ported sounds like. Typically this is formed by years of listening to commercial, or mass market vented subs that are undersized, underported, using a cheap driver,  badly built or braced, tuned way too high, bad integration into the room acoustics, or some combination of all of it. A "good" vented design can sound excellent. I tend to prefer modern, high power, professional woofers for vented cabs. 

SME is correct...Huge spaces and outdoors present  much different problems than smaller domestic sized spaces. Small spaces have a huge impact on the bass range. They often help "turbocharge" the output capabilities of the sub/s, which can help mask operational noises, but can also jack up the frequency response and decay characteristics. Outdoors it is MUCH easier to hear defects in the output of a sub that may be missed entirely in a room. This was part of the Skhorn design process was attempting to clean up as much of the typical operational noises and distortion as possible. It is intended to be used outdoor or 50,000 cu ft venues. In a home it's far more likely that the house and furnishings will be complaining well before a sub like that. This is why I prefer big horns, BP's or vented for high output, big space work. In my home I chose to use sealed subs (4 cabs with 8 drivers total). A single gigantic sub is often not ideal in a small room. 

I get that sometimes you just want a certain thing even though something else may work just as well. I'm guilty of it myself at times. The issue with horn subs is that they have to be big to get to 20Hz or lower. You can cheat a bit and undersize them but then they start to lose efficiency, headroom and the response gets jagged. Even worse is that it starts to cause issues with ringing. This is why most people don't have horn subs in their home. A well designed 20Hz horn is going to be big. This goes for a FLH , TH, what have you. For example the Othorn is pretty small for a high output TH that can really hit 25Hz. This is also the reason that there aren't nearly as many horn subs designed to go to 20Hz or lower. 

Usually when someone starts a thread like this my first questions are these, some of which you've answered.

Budget?

Listening habits: % music / % movies / how loud?

How much space can you dedicate to the subwoofers?

Current system / subs / room?

What do you hope to improve about the sound of your current system?

[Infrasonic]

All these great posts are giving me a bass boner.

 

[m_ms]

On ‎11‎-‎04‎-‎2018 at 2:26 PM, maxmercy said:

F20 and THT are very similar.  THT is tuned higher (~25Hz), and is a little smaller.  Lilmike and I fired up his first F20 build IIRC, and it is capable, but it does need the extra bracing, the first one was not extensively braced if memory serves right, and 1 or 2 outer panels were moving with content.  I have not heard the Othorn, though.  Tapped horns will generally give you more higher order harmonics due to the position of the driver cone.  Running sweeps through sealed and resonant systems does reveal some differences, but after signal shaping, and driven at reasonable levels, the differences get smaller and smaller.  Turning up the SPL will make the differences more audible.

Ricci is probably one of the most experienced people on earth regarding what differing subwoofer systems sound like with high power sweeps and the differences between them.  

If you have multiple sealed systems, they can sound very much like a horn, it is just that you need more of them, b/c in a horn, excursion is kept low through the operating band.  You need multiple sealed units to accomplish the same SPL as a horn with similar low excursion levels.  

F20s are big, but not that big, and on their sides may fit under your mains well, and can be finished in a similar fashion.  They are not that hard to build, and the drivers for them are not budget breakers, but all of the designs you have listed were carefully designed and if well implemented and integrated, should do very well for your goals.

JSS

Thanks for the follow-up, maxmercy - and sorry for the late reply of mine to all here. 

I will be difficult to assess the right sub-path to embark on here, but my gut feeling tells me to go with horns in some variant. Indeed I feel confident in the likely choice of a pair of lilmike's MicroWrecker tapped horn sub. Little of my decision rests in an actual assessment of the pro's and con's of tapped horns, for it could as well (almost) have been the F20, but I believe the MicroWrecker to be slightly better suited to my needs. One of the deciding factors here came with the realization, prompted by lilmike, that two B&C drivers modelled excellently in named horn, and thus it seems this tapped horn can be brought to great fruition with either driver (I'll go with the B&C 15TBX100).

A pair of them in my listening room is overkill, but I'd rather see it as a case of well-needed headroom. Why a pair? Because I want the benefit of more than one sub, headroom included. I was (and still is) very interested in Mr. Ricci's Othorn, but the B&C 21WS152 is simply too expensive for my wallet as is, not giving the opportunity to build a pair of them, and moreover the low corner of the MicroWrecker sits in the low 20's, why I feel to better match HT-duties in addition to music playback. I'm sure a pair of Othorns would've been an absolute crazy delight with sufficient LF-capabilities (indeed an intimidating thought..), but I suspect lilmike's creation will be no slouch in comparison. 

Decision, decisions. I'll let it be known when the build finally commences (depends on some former main speakers being sold first). 

/Mikael

[maxmercy]

That B&C driver models well in horns, you should do well with the Wreckers.  Headroom is a good thing.

JSS

[m_ms]

On ‎11‎-‎04‎-‎2018 at 11:04 PM, SME said:

This is more or less correct.  Each type has its pros and cons, and the end result depends on many other factors.  It's possible to build a sealed sub that is sloppier sounding than a vented sub.  A poorly designed horn or even a good horn that's used outside its ideal range can exhibit more noise and distortion than a better implemented sealed or ported sub.  Among these, choice of driver is also a substantial factor.  And last but definitely not least, the effects of room acoustics and placements on bass are substantial in small rooms.

The relative benefits of sub horns are more apparent when used in large rooms and  outdoors where greater output is needed and distortion is more audible.  Indoors, room acoustic effects are much stronger.  The room acoustics tend to provide low frequency boost, potentially reducing need for output down low and reducing audibility of distortion.  On the other hand, small rooms benefit from multiple subs placed at different locations, and these benefits can extend to frequencies above the traditional sub range in a well-designed system.  For this reason, I believe horns are less attractive for small rooms because of their (typically) large unit size and more limited upper end bandwidth.  That doesn't mean that they aren't a good choice, but the justification is weaker than for large rooms and outdoor spaces.

All speakers and subs have some baseline noise and distortion that are present even at low levels.  However, it's a matter of debate how audible these things are.  Some people claim to be able to hear a difference, but I do have my doubts.  I find that *linear response* (i.e. frequency + phase response alone) including room effects and involving the full musical bandwidth has such a strong impact on perception that it's very hard to reliably judge the non-linear aspects (noise, distortion, and dynamic compression) of  the sound.  I will admit that I myself have had the impression of hearing cleaner sound from my subs as I have upgraded them, but given my experiences with linear response,  I have to second guess myself.

The exception to this may be in outdoor environments.  As @Ricci can attest to, the lack of acoustic effects including room gain together with use of pure tone sine sweeps reveals a lot about the sound that may not be noticed inside a room with "normal" content.

Please allow me to point out a few things.

First and foremost, sub-bass is almost always accompanied by higher frequencies, which have a major impact on the perception of that sound.  In fact, without higher frequencies, sub bass cannot start or stop.  The transient response of sub bass has everything to do with higher frequencies.  Try listening to the sub play with the amps to the mains turned off and note that it's not tight at all.  So if you perceive a lack of "energy" in the 35-65 Hz range, it could be that you are perceiving poor transient response for notes whose fundamental fall in that range, which could involve not just those frequencies but also frequencies up to a few octaves above.

Second, the vast majority of vocal content exists above the sub range.  In principle, the fundamental frequency of the lowest bass vocalists reaches down to around 60 Hz, but even then, almost all the content involves higher frequencies.  Most vocal recordings are high-pass filtered somewhere around 100 Hz or even higher.  (A lot of mic pre-amps have a switch to engage such a filter.)  With an XO of 60 Hz, very little vocal sound should be coming from the sub at all.

None of this is to say that your mains are in any way the cause of the problem, though without quality anechoic measurements, it's hard to say for certain.  Nevertheless, room effects are likely very strong in your case, especially being that you have concrete walls, and it is important to consider them in conjunction with the speakers and subs.  Two kinds of room issues may be involved.  First and most important are room resonances, which are peaks in the response at certain frequencies.  For example, in the 35-65 Hz range, it is very likely that you have one or more strong room resonances.  You probably have some above that range also.  These can have a substantial adverse impact on the sound regardless of what the subs and speakers are capable of.  Room resonances can be addressed by moving the sub or listener, by using additional subs in other locations, or by using EQ to attenuate them.  Room measurement capability is very helpful to identifying problematic resonances and confirming their reduction after applying one or more solutions.

The second potential room issue involves interference causing a suck-out, particularly from the wall behind your speakers.  Being large horns, your speakers are much more resistant to this type of problem than most, but depending on their characteristics including their depth and distance from the wall, they may still exhibit a suck-out down low, for example in the 70-120 Hz range, which is responsible for a lot of bass power and loudness of frequencies an octave below and certainly could influence perception of the lower registers of some vocals.  Unfortunately, the suck-out may be harder to fix.  Moving the speakers will change the affected frequencies, and putting more distance between the speakers and wall will help overall.  Adding fairly thick absorption on the wall behind the speakers (ideally 6" or more, depending on material) can also help quite a bit.

In either case, measurement capability is key to identifying and correcting problems.  It is indispensable.  It can also help you improve the integration between the mains and subs.  With all that said, it's probably still to your benefit to upgrade your SVS sub for those times you like to watch movies or turn music up higher than "65-80 dB".  The key question is what suits you best, and that depends on a lot of things.  I think getting a handle on what your room is doing is a good starting point, especially if you are tempted to get horns.  If you find that you have a lot of room problems above the 60-65 Hz crossover, you might want a sub that can cleanly play higher.

To your last point about your mains not being strained, by running full-range:  Technically you are correct, at least in so far as you aren't pushing them to their limits.  However even if not strained, the baseline distortion from frequencies below the 60-65 Hz limit of the horn will be greatly amplified by the horn.  A high pass filter may still be desired here, especially for movies which can have some pretty hot low frequency content.  The downside to using a high pass filter on the mains is that it may make integration with the sub more difficult.

Thanks for this elaborate reply, SME. Lot's to process here, and I almost don't know where to start. 

The information you provide is overwhelming and extremely helpful, and I'm sorry if I'm cutting my response a bit short here (the hour is late, and I'd like to reply to all here before I'll crawl under the duvet). First on whether to go with horns or not, I'm getting the vibe to rather pursue a vented solution due to the relatively restricted size of my listening room, and you wisely call to attention many factors that contribute to the outcome. I'll admit to have never heard a "commercial" horn sub in a domestic environment, and so I'm in no position to counter any advice here given my preference for a horn sub. They're big as hell, and likely so powerful that they could pop out the windows of our apartment if given a "carte blanche" ride. As Mr. Ricci pointed to I might only make use of some 10% of the Othorns in my setup and surroundings, and so why would I ever seek out such a solution (or in that ballpark) when there are factors here that could even be detrimental? One thing to stress: I got all-horn speakers, and it seems to me there's not much talk about how to compliment them the best way downwards with a sub. From a very crude standpoint I take it horns match horns the best. 

Putting the listening room into the equation is vital feedback, thanks. I'll use your advice for sure. 

I would have to find one heck of a high-pass filter to put my main speakers through - that's my main concern. Such requires a rather pricey solution I'm sure, and would have to be implemented down the road. Remember my speakers are very sensitive; any noise issues will be swiftly exposed as well. 

[m_ms]

On ‎12‎-‎04‎-‎2018 at 12:07 AM, lilmike said:

Yes, that was the original build. Completely unbraced, but I did use decent 3/4" plywood. In hindsight, it would have benefited from some bracing. 

One thing to note - when turning up tapped horns, it has been my experience that the response flattens out as they approach war volume. Of course, war volume SPLs in an apartment might make for war with the neighbors. 

I like that expression: war volume. Stretching a pair of horn sub legs like the MicroWrecker in our apartment would likely wreck many a thing indeed (and have our 11-month son somersault)... 

[m_ms]

On ‎12‎-‎04‎-‎2018 at 7:23 PM, Kvalsvoll said:

The typical consumer subwoofer will never deliver a sound character similar to what you experience with your horns. But that does not make it useless, it fills in the deep bass below where the horns roll off, and for a lot of music most of the bass is reproduced from the horns.

From what you write it looks like you have identified this difference in sound, and now start to wonder if it is possible to achieve a sound more similar to the horns at lower frequencies. And it is possible. But of course the lower bass will by nature sound different and give a different experience compared to the upper bass range, where most of the attack and kick is.

One way to achieve this is to build something yourself, use a pro driver with limited excursion and high BL, place it in a ported cabinet that is too large and ported too low.

Thanks for chiming in, Kvalsvoll. 

That's exactly what I'm after. I hope I'll not be far off with my finale choice..

[m_ms]

On ‎12‎-‎04‎-‎2018 at 9:50 PM, Ricci said:

Vented boxes can have problems that have resulted in a common preconception of what ported sounds like. Typically this is formed by years of listening to commercial, or mass market vented subs that are undersized, underported, using a cheap driver,  badly built or braced, tuned way too high, bad integration into the room acoustics, or some combination of all of it. A "good" vented design can sound excellent. I tend to prefer modern, high power, professional woofers for vented cabs. 

SME is correct...Huge spaces and outdoors present  much different problems than smaller domestic sized spaces. Small spaces have a huge impact on the bass range. They often help "turbocharge" the output capabilities of the sub/s, which can help mask operational noises, but can also jack up the frequency response and decay characteristics. Outdoors it is MUCH easier to hear defects in the output of a sub that may be missed entirely in a room. This was part of the Skhorn design process was attempting to clean up as much of the typical operational noises and distortion as possible. It is intended to be used outdoor or 50,000 cu ft venues. In a home it's far more likely that the house and furnishings will be complaining well before a sub like that. This is why I prefer big horns, BP's or vented for high output, big space work. In my home I chose to use sealed subs (4 cabs with 8 drivers total). A single gigantic sub is often not ideal in a small room. 

I get that sometimes you just want a certain thing even though something else may work just as well. I'm guilty of it myself at times. The issue with horn subs is that they have to be big to get to 20Hz or lower. You can cheat a bit and undersize them but then they start to lose efficiency, headroom and the response gets jagged. Even worse is that it starts to cause issues with ringing. This is why most people don't have horn subs in their home. A well designed 20Hz horn is going to be big. This goes for a FLH , TH, what have you. For example the Othorn is pretty small for a high output TH that can really hit 25Hz. This is also the reason that there aren't nearly as many horn subs designed to go to 20Hz or lower. 

Usually when someone starts a thread like this my first questions are these, some of which you've answered.

Budget?

Listening habits: % music / % movies / how loud?

How much space can you dedicate to the subwoofers?

Current system / subs / room?

What do you hope to improve about the sound of your current system?

Mr. Ricci --

I'm sure you're right about calling out in a sense my preconceived stance on ported subs (or at least a stance that's based on limited experience), and that great sounding vented designs are out there -  contrary to my experience. For some time now though I've got my head wrapped around implementing a pair of horn subs in my setup, and it's not to say I'm inflexible on other ways to make great bass (hopefully), but I just still don't see any compelling reasons to abandon a horn sub approach. I don't see you, or others here doing that per se, but more that you may try and prevent me from making some bad calls, and for that I'm actually thankful  

Regarding the size of horn subs, the solution I'm likely to implement, namely lilmike's MicroWrecker, is by no means a shoebox, and I'm sure I'll shake my head in blunt realization once they're eventually placed in my listening room, a pair of them not least, and wonder what the hell I was thinking. I still don't mind their size though (unless it affects the sound negatively), for I have a dedicated listening room, and as such the only thing impractical is getting them transported to the 2nd floor (hopefully without the pale-faced witnessing of my neighbors, with the thought of what they're about to be treated to).

One thing that's left out by you is this, perhaps for a very good reason: considering the sound of the subs. Bass is not simply bass, is it? Doesn't the sound from the different horn subs you've made differ, and isn't there something about the Othorn that makes people calling it "the most musical sub" they've ever heard? Perhaps running subs of different designs up to no more than 10-15% of their capabilities will render the bass they produce very similar (if they're all well implemented), I don't know, but I find it hard to believe if one truly and critically listens to them (and I'm not implying you don't). That being said, you're the one with experience here, a lot of it, and that brings me in a disadvantage. 

To your questions:

Budget: $2,500, or thereabouts (for subs) 

Listening habits: % music / % movies / how loud? 70 / 30 / 65-110dB's (the latter number is the occasional "bursts," not average, with either films or music)

How much space can you dedicate to the subwoofers? Listening room is ~1,900 cu. feet 

Current system / subs / room? NAS drive > SOtM sPS-500 PSU > SOtM sMS-200ultra 12V network player > SOtM sDP-1000 DAC/preamp > Belles SA-30 pure Class-A power amp > Simon Mears Audio Uccello's all-horn main speakers > SVS SB16-Ultra sub (one)

What do you hope to improve about the sound of your current system? Integration, the positive of using more than one sub, and that effortless sense of air-vibration, envelopment, and visceral impact 

[m_ms]

1 hour ago, maxmercy said:

That B&C driver models well in horns, you should do well with the Wreckers.  Headroom is a good thing.

JSS

Happy to read this  

[SME]

As I said, the question of whether horn subs have a "unique sound" that can be heard indoors is debated.  Actually, that discussion assumes quality drivers and a competent build to begin with.  Ideally, a sub shouldn't have a distinct sound at all beyond that which can be adjusted using EQ, but it's not hard to get a distinct (bad) sound from a sub that's poorly designed or poorly built.  That goes for sealed, vented, and horn subs alike.

As for what integrates best with your horn speakers, the question of sound characteristic is not especially relevant here.  The sound depends far more on the effects of the room on the chosen placements for the sub(s) and listeners, any EQ or crossovers that are used, and the linear response of the sub at its upper limits.  As I said, horn subs have more limited upper frequency capability, which makes them less flexible in small rooms.  This means that you may be able to achieve better integration with the mains by *not* using a horn sub.  It's really a minor thing, but I believe it's a lot more important than sound characteristic.

In terms of sub design choice, the relevant questions are how much SPL you want with what kind of extension, how much space you have, how much effort you are willing to put into the build, and much money you are willing to spend.  A pair of decent sealed 18"+ subs will give you plenty of SPL and extension for the modest listening levels you indicated.

It seems to me that you've already made up your mind that horns are the only way to go.  If so, then there's likely nothing any of us can say to convince you otherwise.  And to be fair, you'll probably do just fine with horn subs like the  F20. However, if you are serious about getting best integration with the mains  or with choosing a design that fulfills your needs while better fitting your budget for money and space, you should definitely consider other design types.

FWIW, I'm running 4 x high performance sealed 21" cabinets which get pushed to 125-130 dB from time to time.  I chose them because I was space constrained, wanted a lot of extension, and was willing to spend the money.