SME

(4) Sealed 21": Funk Audio UH-21v1

168 posts in this topic

 

It *looks* like it's filtered below 10 Hz, but I verified that the test signal extends below there.  As I said before, my suspended floor is pretty much a no-show in the single digits.  The PSD doesn't even show any activity at 5.5 Hz.  Though I've verified the existence of a very high Q floor-wobble resonance there.  The low teens response peaks at 12 Hz, but that's because my cal leaves the worst of the resonance at 11 Hz notched out.

 

full band pink noise will contaminate the PSD reported by VS because any high(er) frequency vibration will be aliased into the reported results. Use 0-50Hz white noise instead, the signal itself is then a straight line in PSD so it's easy then to see the variation between measured and actual.

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full band pink noise will contaminate the PSD reported by VS because any high(er) frequency vibration will be aliased into the reported results. Use 0-50Hz white noise instead, the signal itself is then a straight line in PSD so it's easy then to see the variation between measured and actual.

 

Mmm, aliasing.  Too bad I can't boost the sample rate in VS.  But why not use pink noise filtered at 50 Hz?  Also, I don't see a white noise generator in REW.  Can you suggest a place to download a test sample?  Otherwise, I guess I'll have to make my own.

 

Edit: I'm also concerned that white noise will have very poor SnR for ULF, and I can't seem to make the capture duration any longer than 1 minute.  (After all, the previous pink noise measurement largely failed to reveal my 5.5 Hz resonance.)

Edited by SME

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That is a lot of boost going in from 7-14Hz. That is definitely where your demands on the drivers and amps is going to be heaviest. Looks like a boundary related loss over that range for sure. At least it should cause a big tactile shake though. I'd bet that a vibration test picks up strong signals in that range.

 

We'll have to wait until I can fix my vibsensor measurements, but in any case, I don't get much shake outside of 11-13 Hz.  Even at 10 Hz, the shaking effect is almost nil without crazy SPL.

 

Edit: After re-testing using filtered pink noise to avoid aliasing, I'm seeing even less tactile activity below 15 Hz vs the low 20s.  FWIW, my room-gain profile has a  tall broad peak around 20 Hz.

Edited by SME

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Mmm, aliasing.  Too bad I can't boost the sample rate in VS.  But why not use pink noise filtered at 50 Hz?  Also, I don't see a white noise generator in REW.  Can you suggest a place to download a test sample?  Otherwise, I guess I'll have to make my own.

 

Edit: I'm also concerned that white noise will have very poor SnR for ULF, and I can't seem to make the capture duration any longer than 1 minute.  (After all, the previous pink noise measurement largely failed to reveal my 5.5 Hz resonance.)

there's no problem using pink noise, it's just easier to compare measurements when using white. 

 

REW does have white noise in its generator, it's listed as "White PN" IIRC. There are a bunch of test signals in https://drive.google.com/open?id=0BxdmSMpV-t3GVzlJcnhYaDJhdmc, they're just REW generated though.

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I filtered my pink noise sample using Audacity.  The roll-off starts at 40 Hz and is pretty steep, so aliasing should be minimal.  I did two captures in a row to assess repeatability:

 

subs-vib-psd-mlp-2017-07-10-1.png

 

subs-vib-psd-mlp-2017-07-10-2.png

 

Hmm.  This doesn't look so good.  I can maybe boost the level another 10 dB or so (average level ~105 dB SPL), but that'll have to wait until tomorrow.

 

there's no problem using pink noise, it's just easier to compare measurements when using white. 

 

REW does have white noise in its generator, it's listed as "White PN" IIRC. There are a bunch of test signals in https://drive.google.com/open?id=0BxdmSMpV-t3GVzlJcnhYaDJhdmc, they're just REW generated though.

 

Pink noise will offer substantially better signal-to-noise ratio for lower frequencies, which is important in my case as my SnR seems to be borderline even with pink noise.

 

"White PN" and "Pink PN" generate periodic noise, which means it's only random over a specified number of samples, up to 131072 in the case of REW.  I would not trust such signals to provide reliable data where resolution on the order of 1 Hz is required.

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Hmm.  Running the captures with more SPL proved a bit tricky.  When I normalized the test signal, boosted the level in my AVR to its max, and then tested, I ended up triggering the DC signal protection on my AVR.  Whoops!  :)

 

Next, I applied the boost at the DSP, instead.  That worked OK, but watching the peak indicators made me worry about the amount of power I was putting into the woofers over a minute long interval.  So I backed off about 5 dB to be cautious.

 

This time, I verified the level of the pink noise using REW and my calibrated Umik.  For these tests, I measured avg SPL of 97 dBZ.  It's possible the actual SPL was higher due to content below 5 Hz where the mic rolls off and is no longer calibrated.

 

I did a total of three tests.  The first two involved placing the phone in the exact same location, right in the middle of the MLP seat cushion.  I verified that these were very close to the same (woohoo!), so I am only posting one of these results.  The third test involved placing the phone on the near edge of the adjacent seat cushion, about 12" away.  I'm not sure I got the orientation exactly the same, so the X and Y axes may be a bit different, but most of the action is in the Z axis.

 

subs-vib-psd-mlp-97d_BZ-2016-07-11.png subs-vib-psd-cr_c_edge-97d_BZ-2016-07-11

As you can see, the measurement changed quite a bit, despite this small spatial shift.  While the low teens resonances and lack of vibration below 11 Hz persist, the activity in the upper teens, twenties, and thirties looks quite a bit different.  Mind you, my butt is wider than 12", so this raises a lot of question about how these kinds of measurements should be interpreted.  Let's also not forget that merely sitting on or leaning against these cushions may significantly change their response too.

 

At least the parts of the response that remain consistent merely confirm what I already believed based on my subjective experiments using pure sine waves as well as listening to actual content.  The most obvious areas with respect to couch and floor shaking are the 11-13 Hz region and the low twenties.  Outside of those ranges, I do still notice the seat cushions vibrating if I pay attention, but not really the floor.  And at the point I feel the sofa vibration, I'm usually beginning to feel it in my clothes, on my skin, or inside my body too.

 

Out of curiosity, are there any measurements like this out there that I can compare to my own?  I'm just curious about how this data looks in terms of absolute quantity vs. other systems.  I looked around on AVSForum and whatnot and couldn't find anything.

 

To be clear, my data would have to be adjusted to be "compatible with" measurements involving filtered white noise instead of filtered pink noise, which I used.  In terms of relative response, one can recover the "white noise" version by subtracting 3 dB from the data for each octave away from 40 Hz.  Note that the Y-axis is specified in absolute units of "g" rather than dB, but each major grid line is a 10 dB increase over the one below.  Absolute comparisons would be trickier as it really depends on a lot of details of how the test signals were created, but the different methods should at least be consistent within a rough order of magnitude.

 

At least, it should be clear at this point that excepting those narrow resonances around 11-13 Hz, my couch shake response to ULF is not especially different in the 7-14 Hz range where my subs have to work harder.  And in fact, my shaking response peaks at around the same frequencies that my room-gain peaks.

Edited by SME

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http://www.avsforum.com/forum/113-subwoofers-bass-transducers/2434250-nearfield-ported-mbm-increased-mid-bass-tactile-response.htmland particularly http://www.avsforum.com/forum/113-subwoofers-bass-transducers/2118090-vibsensor-accelerometer-test-thread.html are where you should find other measurements, not sure how many have been photobucketed though.

 

Generally speaking people have been weighing down the phone with a sack of rice (or similar) to keep the thing under control at low frequencies. This also damps the response above 30Hz or so from what I have measured but does seem to produce a shape to the response that more closely resembles that of a lighter, more accurate and securely attached, sensor. You can avoid this by using such an external sensor.

 

Sitting on the seat does naturally change the measured response. I posted a comparison somewhere on avs at some point iirc.

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Thanks for the links and for the tips.  Unfortunately, the majority of posted images were Photobucketed, as you say.

I did look at a few images.  Because most of the measurements were of the "Edge of Tomorrow" opener, which is a very different kind of signal, I decided to look at the vibration vs. time data instead.  I can post a screen-shot of that measurement it if people want me to, but I think it's rather boring.  It looks quite a bit like pink noise.  Recall that the test sample is pink noise which is filtered fairly steeply at the top between 40-50 Hz and played at around 97 dBZ RMS, according to my mic, which is not calibrated below 5 Hz.

It looks like my RMS vibration values came out to roughly 0.0055 in the X and Y axes and 0.025 in the Z axis.  With a little math, I can extrapolate this to the higher levels that would likely present with peak effects, say 15-20 dB hotter, which is a factor between roughly 5 and 10 for a "level quantity" like acceleration.  So with pink noise at a more spirited level, I could maybe push over 0.25g on the *really hot* effects.  I believe that on something like a PvA, the pink noise response should rise toward the bottom by about 3 dB/octave, which is not unusual for some of the stuff that's bottom heavier.

Comparing these extrapolated results to what I see in the thread, it seems I'm coming out on the low end of the results.  Unfortunately, very few people are measuring or reporting SPL along with their vibration response, so it's hard to tell just how hot people are running things on that end  Furthermore, The "Edge of Tomorrow" opener is not a very useful test signal, and it's most of what I could find on the early pages.  While each fundamental frequency in the sequence hits a different part of the deep bass / ULF spectrum, the overall coverage of the spectrum is extremely narrow.  I'm thinking that tomorrow I will try measuring a slow sine sweep.  Unfortunately, without getting at the raw data and analyzing it, I won't get the kind of noise rejection that sine sweep impulse response measurements benefit from.  I could always buy the app and whatnot, but if I'm going to spend money, I'd rather do it right.  For now it's not a priority.

 

I'm not especially bothered by the fact that my readings appear to be low.  I see a lot of enthusiasm in the thread about gains made by doing stuff like mis-aligning the timing of the subs and compromising frequency response.  And of course, there's the interest paid to (alleged) differences between ported and sealed subs.  But I have to ask:  Is this what we really want?  Is tactile response so important that aspects of performance related to frequency response should be compromised?  This is an especially important question when one considers that a lot of these responses may be quite ugly and full or resonances.  Mine sure is in the low teens.  This makes for a pretty lo-fi experience, all things considered. 

Another thing is that, to the extent the floor is shaking, it's likely the walls are shaking too.  That can add a lot of unwanted noise to the bass experience and really kill the immersion.  That's something that I believe improved with my multi-seat EQ optimization, and I wouldn't be surprised if my EQ optimization reduced my couch vibrations too.  Is that really a bad thing?  I happen to really how it sounds, and I can clearly hear ULF well into the low teens when it's above hearing threshold levels.  I also love the very tight transient response and "bottomless" quality of the sound on un-ftilered tracks.  And if the level is up there, I feel plenty of tactile sensation.  It's just rather different from couch shake.

On another note, I definitely think I experienced more shaking with the old Hsu subs, which were ported and tuned to 18 Hz or so.  However, I noticed this even more at higher frequencies, like 25-50 Hz, above which the near-ish field MBMs took over.  I seriously doubt that the fact that they were ported had anything to do with the higher frequency sensations.   My strongest suspicious is that this shaking was caused by mechanical vibrations of the cabinet.  The D.O. configuration eliminated those and thus "cleaned up" a whole lot of floor vibration.  It took some time to get used to less shaking, and I did opt to boost the subs a bit more than before.  But I'm OK with the change.  To me, having a more vibrationally inert presentation is more accurate and realistic.

 

In other news, I can add "The Incredible Hulk" to the list of movies that I *cannot* play at my preferred listening level with my system as it is calibrated.  The university scene played just fine, and was actually a lot of fun.  The cop car smash scene did not work out so well.  The big hit at the end (when there's practically nothing left of the car) is enough to light up the orange clip lights, at only "-9" on the MV.  My preferred level would be more like "-5".  For all the effort I went through to get as much ULF as possible out of this system, it's still not enough for these most demanding scenes.  When I upgrade the amp power source to 240V, I should get another 3 dB of headroom, but I doubt it will be very useful, being that the drivers are probably close to their clean max excursion.

What disappointed me more is that I honestly can't say whether I the perceived low end of that content.  Was that effect at 8 Hz?  If it was there, it was very subtle.  Maybe if I paid attention, I could feel my hair move or something.  This is something I'll want to double blind test later along with ULF on more transient sounds.  It may be that this content just isn't hot enough to perceive without the help of floor/couch motion, and clearly, I have very little of that below 11 Hz.  This would then imply that the content under 10 Hz is of no interest in an *accurate* presentation.  The only way you'll know it's there is if the floor or furniture is vibrating to it or if the subs are distorting enough to enhance the phantom fundamental.  In a studio with concrete floors and no motion actuators, it may not be perceived at all.

This does make me seriously consider Crowson's.  If the goal is to make the couch shake, I'd rather use the right tool for the job.  Although, this kind of upgrade will be a fair ways off.  Unfortunately, I'd need another Motu unit for more output channels.  And then I have to worry about my racks getting cramped with an extra amp or two.  My sofa is a 5 piece sectional, which is rather inconvenient, not to mention expensive.  If I used Crowsons, I think I would low pass them at around 20 Hz.

As for the subs, I guess it all depends on how I feel after double blind testing.  I have a lot of options there.  I can EQ things less aggressively down low.  I can use less boost below some frequency.  I can also try to implement some kind of frequency-selective limiting, though this gets tricky with ULF if I want to avoid unnecessary phase shift.  Another option I might consider is a bit more of a ramp in the ULF, which I can probably get away with if I ramp down or high pass below 10 Hz.  There are still a lot of possibilities to explore.

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3 hours ago, SME said:

I'm not especially bothered by the fact that my readings appear to be low.  I see a lot of enthusiasm in the thread about gains made by doing stuff like mis-aligning the timing of the subs and compromising frequency response.  And of course, there's the interest paid to (alleged) differences between ported and sealed subs.  But I have to ask:  Is this what we really want?  Is tactile response so important that aspects of performance related to frequency response should be compromised?  This is an especially important question when one considers that a lot of these responses may be quite ugly and full or resonances.  Mine sure is in the low teens.  This makes for a pretty lo-fi experience, all things considered. 

In other news, I can add "The Incredible Hulk" to the list of movies that I *cannot* play at my preferred listening level with my system as it is calibrated.  The university scene played just fine, and was actually a lot of fun.  The cop car smash scene did not work out so well.  The big hit at the end (when there's practically nothing left of the car) is enough to light up the orange clip lights, at only "-9" on the MV.  My preferred level would be more like "-5".  For all the effort I went through to get as much ULF as possible out of this system, it's still not enough for these most demanding scenes.  When I upgrade the amp power source to 240V, I should get another 3 dB of headroom, but I doubt it will be very useful, being that the drivers are probably close to their clean max excursion.

What disappointed me more is that I honestly can't say whether I the perceived low end of that content.  Was that effect at 8 Hz?  If it was there, it was very subtle.  Maybe if I paid attention, I could feel my hair move or something.  This is something I'll want to double blind test later along with ULF on more transient sounds.  It may be that this content just isn't hot enough to perceive without the help of floor/couch motion, and clearly, I have very little of that below 11 Hz.  This would then imply that the content under 10 Hz is of no interest in an *accurate* presentation.  The only way you'll know it's there is if the floor or furniture is vibrating to it or if the subs are distorting enough to enhance the phantom fundamental.  In a studio with concrete floors and no motion actuators, it may not be perceived at all.

This does make me seriously consider Crowson's.  If the goal is to make the couch shake, I'd rather use the right tool for the job. 

I quoted the parts I agree with most. The first paragraph is the same type of thing I have been thinking about the trend of maximum vibration chasing. I don't doubt that having a good FR, lots of SPL AND vibration, are all important aspects to consider. Some of what seems to be being suggested in those threads (That you mentioned) seems like very bad advice to me. I remember someone suggested using smaller vents to increase their particle velocity.

With the amount of boost you are using Hulk will be a difficult load on your amps and drivers for sure. The cop car punch is a short but tough signal. I think a 7 or 8Hz fundamental is about right.

Without tactile vibration to help transfer the <12-15Hz content it is barely there in my experience.

Below 10Hz it's pretty uneventful without a major structural vibration to go with it. It makes all the difference. 32hz at 115dB is very apparent, you feel it and it is loud. 16Hz at 115dB is much less obvious but with that kind of level you can sort of hear it and still feel it. Somewhere around 12-13Hz for me it becomes hard to hear much of anything anymore unless it is strong as hell and even then it's just an odd modulation on everything else. Pressure waves like a rapid on/off switch on the ears. I've heard 12-13Hz at 115dB or so outdoors with test tones and it was subtle. It was like the rest of the background sounds I was hearing were coming from behind a fan. My current HT room is very solid. I get a ton of gain and SPL but very little shake other than from the ceiling. The single digit stuff is an occasional odd pressure sensation if it is very loud and not masked by other content and that's about it. I don't think I would miss much in my room if I only got down to the 10-15Hz range.

I expected that you would have a ton of vibration near your notch in the teens. I'm surprised that you don't show more. If the energy isn't being exchanged there where is it going? That should be too low of a frequency for it to be a null induced by the room dimensions.

 

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I don't think it's fair to characterise those threads as maximum vibration chasing. Obviously there are some people who do that, just as there are people who chase extreme SPL, but mostly it's about finding out how it responds & what feels right/good. There seems a lot of variation on that point, or more specifically, the way people describe what they like seems to vary a lot.

It's all about balance in the end.

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I no  longer boost my subs down low chasing a flat freq response.  I just use the crowsons for the <10Hz stuff (and sometimes significant amounts above 10Hz, esp at lower SPL listening).

 

JSS

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Pretty much with you SME on some of that but Ricci has worded it the way I would.... Thanks.

 

2 hours ago, 3ll3d00d said:

I don't think it's fair to characterise those threads as maximum vibration chasing. Obviously there are some people who do that, just as there are people who chase extreme SPL, but mostly it's about finding out how it responds & what feels right/good. There seems a lot of variation on that point, or more specifically, the way people describe what they like seems to vary a lot.

It's all about balance in the end.

Ahh... thanks. I wanted to say that I find this tactile data useful but I'm not like... "chasing vibrations". SME, you mention tactile sensation as if it were mutually exclusive to a hi fidelity experience. It's not. I find that it to be an integral part of a bass experience. Every awesome bass I've heard in my life was also felt.

Compromises are always made in any system. And every one has their preferences.

 

 

Anyway... not raggin' on ya.

I'm sad to see you run into what many of us recently are discovering. That sub 10hz bass is kinda .... often it can be a non-event. Tactile response is CRITICAL below 15hz. I like sealed and I'd like to try again and do it a bit better but there are days when I wish I had LLT's again. *sniff*

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Since you want to listen a lil louder, SME... just lower the boost by the number of dB you want.

Really doesn't matter since you say you couldn't appreciate the single digits as much as you hoped you would. Open up more headroom where you want it!

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5 hours ago, Ricci said:

I expected that you would have a ton of vibration near your notch in the teens. I'm surprised that you don't show more. If the energy isn't being exchanged there where is it going? That should be too low of a frequency for it to be a null induced by the room dimensions.

Do you mean the notch at 11 Hz or the octave wide dip across the 7-14 Hz region?  At the 11 Hz notch, things do shake pretty bad.  I probably mentioned already, but when I probe that notch using sine waves, SPL in the low 100s dB is enough to cause some serious ceiling shaking and causes my dining room lamp to literally bounce up and down and start swinging.  I fear that much more output in the narrow vicinity of that frequency will damage something, so I leave the notch there.

As for the broader dip though, there isn't much happening other than at the notch and a little bit above it.

BTW, my house is about 48 feet in length, which suggests that my primary "room mode" should fall right at about 12 Hz.  If you look at my raw measurements, the red traces are closer to the end of the house and so should theoretically have more output than the blue traces.  Likewise, the left sub is closer to the house end so should measure hotter overall.  In both cases, the opposite is actually true.

2 hours ago, Infrasonic said:

Ahh... thanks. I wanted to say that I find this tactile data useful but I'm not like... "chasing vibrations". SME, you mention tactile sensation as if it were mutually exclusive to a hi fidelity experience. It's not. I find that it to be an integral part of a bass experience. Every awesome bass I've heard in my life was also felt.

Compromises are always made in any system. And every one has their preferences.

Anyway... not raggin' on ya.

I'm sad to see you run into what many of us recently are discovering. That sub 10hz bass is kinda .... often it can be a non-event. Tactile response is CRITICAL below 15hz. I like sealed and I'd like to try again and do it a bit better but there are days when I wish I had LLT's again. *sniff*

No, I don't mean to say that tactile sensation is exclusive to hi-fidelity at all.  I was referring to couch shaking specifically, which is what these vibsensor tests are measuring.  In my experience, tactile sensation is multi-dimensional.  The couch/floor shaking is one dimension.  The interaction of sound in the air with the body directly is another dimension.  I believe these sensations feel quite distinct from one another.

Typical studios probably have inert floors (e.g., concrete under the flooring material).  Engineers are even known to go out of their way to reduce floor vibrations in their studios, at least at higher frequencies.   If the shaking is too strong, there is a tendency for the those sensations to overwhelm and mask the sensations that are felt from the sound directly.  The shaking response is also a lot less likely to be flat when SPL response is, and this could cause mixers to misjudge what's going on in the mix.  By my subjective assessment, my old Hsu subs shook things a lot more, and I believe that the shaking was so strong below 30 Hz or so that it overwhelmed most of the direct tactile sensation there.

Anyway, I don't mean to say that shaking sensations are "wrong".  For some kinds of effects like earthquakes, shaking probably *is* the appropriate sensation.  With something like thunder though, a lot of shaking is probably a lot less realistic, especially if the depicted scene is outside.

I think it would be interesting if the standards provisioned an extra "SEX" (shaking effects) track, kind of like LFE, that's intended to be sent directly to tactile transducers (TTs).   This would give sound designers a way to express  the intent.  For example, a thunder sound effect could be routed exclusively to the subs, and an earthquake effect could be routed exclusively to the TTs.  It's a shame that we can't even get the industry to acknowledge a role for ULF in any capacity, even though many cinemas are now installing shakers in their seats

 

And yeah.  I guess my experience is more evidence that content under 10 Hz is not especially relevant in terms of pure sound.  And furthermore, my experience should serve as a caution to those with suspended floors who would expect to feel single digits content if they install sealed subs.  Clearly, a suspended floor offers no such guarantee.  It all depends on the resonances.  And since a response supported by resonances is not going to be high-fidelity, it may make most sense to recommend 10 Hz as the lower limit for subs and leave the single digits for tactile transducers.

It'll be very interesting, when I get around to it, to find out whether I or anyone can identify the existence of single digits content from my subs in double blind testing.

 

Edit: I should mention that I really like what I experience with good dynamic music BDs.  The bass is a lot like listening outdoors, including the nice sharp punch from the kick drum.  Breathing feels kind of weird with these sensations.  And this is with the sub out channels barely getting above the "-48 dB" line on my Motu.  :D  The thing is, I don't think a couch vibration measurement will reveal this "punch" dimension of tactile experience, which also happens to depend a lot more on frequencies between 50 and a few hundred Hz.

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On ‎7‎/‎14‎/‎2017 at 3:31 PM, SME said:

Do you mean the notch at 11 Hz or the octave wide dip across the 7-14 Hz region?  At the 11 Hz notch, things do shake pretty bad.  I probably mentioned already, but when I probe that notch using sine waves, SPL in the low 100s dB is enough to cause some serious ceiling shaking and causes my dining room lamp to literally bounce up and down and start swinging.  I fear that much more output in the narrow vicinity of that frequency will damage something, so I leave the notch there.

As for the broader dip though, there isn't much happening other than at the notch and a little bit above it.

Ok. That makes more sense. That sounds similar to my old room over a crawlspace. Little measured SPL at 12Hz but the floor was violently shaking.

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I thought I'd mention that I've experimented a bit with a "tilt" tone control in my custom EQ.  The tilt control I implemented is basically just a pair of shelves, one high shelf and one low shelf centered at a common frequency and a very low Q.  The f0 and Q I'm using are inspired by Quad preamps, which offered an analog version of such a control, and I can thank Floyd Toole for dropping the hint:

  f0 = 800 Hz

  Q = 0.32

The gain is adjustable.  This results in a smooth transition between roughly 80 and 8000 Hz.  This control is helpful for tweaking some music which leans a bit too much toward the top or bottom, but it also seems to work real well for a kind of "party mode" EQ, where I might want a lot more bass for typical music recordings than a "balanced" presentation offers.  When adding a lot of boost, I tend to add just a bit more to my "normal" sub boost.  IIRC, I was doing about 1 dB more sub per 5 dB tilt.

The nice thing about the tilt control is that the boost is spread out across many frequencies, so I can achieve a lot of boost with relatively little harm to the overall tonal balance of the mid-range.  I can also get a lot more sub bass to play without losing punch and definition as tends to happen when boosting the sub too much.

As an experiment, I listened to some songs from "Liquid Stranger - The Intergalatic Slapstick", an album with dub-step like elements that has a lot of heavy mid-bass and is not as crushed as some.  I enabled a 10 dB tilt and added an extra 2 dB (IIRC) to the sub.  With the tilt in place, I could turn the master volume up a lot higher while maintaining comfort.  I pushed up as high as "-1", and with the tilt (+5 dB to the sub) and sub boosts combined, my subs were probably doing about 10 dB above reference.  The result was definitely loud, but entirely comfortable to my ears.  I actually got the subs to work a little bit, with peak indicators getting off the "-48 dB" bottom.  I estimate bass SPL was pushing into the mid one-teens if not a bit higher, yet the music remained very clear.  The bass was punching hard, and some of the sustained notes were causing the hollow door to my basement to rattle like crazy.

After playing a few songs this way, I turned things off and noted no obvious hearing TTS (temporary threshold shift), which is a real plus.  I did feel a bit like I'd just gotten off an amusement park ride though.  :)  The subs had plenty of room to go further, but my mains were actually being pushed enough to make me hesitant to go much higher.  They certainly had spare headroom, but I'd rather keep them nice sounding.

My biggest concern with "party mode" is my neighbors.  I'm not in a basement, so I'm afraid someone will complain if I play like that very much.  Still, it will be fun to use for demos.  It's one thing to make a lot of bass, but to do so while minimizing compromise of the mid and highs is a real plus.  This gives me more impetus to go with the plan to install 2 of the pairs of TD10Xs between the mains and subs to boost the low mid/mid-bass capabilities and create a quasi line-array of sorts.  With those installed and a more clever crossover involving the subs, I expect I'd gain something like 10-15 dB more headroom for this sort of activity.  :D  On the downside though, the loss of mid/high clarity does seem to increase pretty rapidly when tilting more than 6-10 dB or so.  I'll also have to find a way to stop that annoying door rattle.  Aside from that and a loose window pane or two, everything else in the house is pretty much silent, even with high SPL.

Hmm.  Maybe next I'll have to try some Infected Mushroom.  I don't have anything of theirs beyond "Converting Vegetarians", but that album has some stuff that punches pretty hard even without EQ.  I'll have to try some concert BDs too.  Hmm.

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Very interesting, I'll have to try something like it.  So for every dB up on the low shelf, the high shelf shifts down?

I have a request, SME.  On the BEQ thread, you noted the Vader ship coming out of hyperspace was a terrific transient.  Since you can adjust your DSP essentially on the fly, can you try that effect with and without a 10-15Hz highpass to see if the <10Hz content is really making a difference in a transient like that one?

 

JSS

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On 8/1/2017 at 6:28 PM, maxmercy said:

Very interesting, I'll have to try something like it.  So for every dB up on the low shelf, the high shelf shifts down?

I have a request, SME.  On the BEQ thread, you noted the Vader ship coming out of hyperspace was a terrific transient.  Since you can adjust your DSP essentially on the fly, can you try that effect with and without a 10-15Hz highpass to see if the <10Hz content is really making a difference in a transient like that one?

 

JSS

Yep.  You got it.  The center frequency is a kind of pivot point that doesn't change.  Everything above it is reduced.  Everything below it is boosted.  So in my example above, response at 800 Hz is unchanged.

I tried it with some other music, and it didn't work quite as well as I hoped.  Some stuff would seem to be quite loud in the mids already, and the tilt didn't allow for much gain in comfortable playback level.  Perhaps different center frequencies would help with different music.  Some day, I'll make the adjustments interact so I can hear instantaneous feedback.  That'll make it a lot easier to tweak things.

As per your request, I will try to do this soon.

I've been distracted by other stuff lately, including working on another iteration on my speaker EQ.  I significantly improved the mid-range by working at 1/12 octave resolution in addition to 1/3rd octave.  This probably helped deal with some stuff related to cabinet diffraction.  I also further improved some of the resonances in the treble.  These changes allowed me to boost 15-20 kHz quite a bit more (to nearly flat) without the uncomfortable ear sensations or weird masking issues (including in the bass) I was having before. 

What's weird is that their sound now reminds me even more of the sound of the M2s from my audition.  However, my system has much better bass than what I heard, and the ultra high frequency content (and associated magic) doesn't fall off nearly as much when moving my head off-axis as it did with the M2s.  :)  Better yet, these speakers were way cheaper to build and have as much or more output using my silent Emotiva amps as opposed to the screamers (that also gave off weird smells when pushed) that the M2s require.

I do still have some minor issues to work out, including some edginess around 2 kHz and a need to dial-in the ultra high boost more carefully to keep ultrasonic resonances under control.  I had the family over today and hadn't had time to run through much stuff.  Only after they left and it was quiet enough could I confirm what I thought heard, which was too much fullness at 200-400 Hz.  I was wondering why Rebecca Pidgeon's voice lost all intelligibility.  They call that the "mud-range" for a reason, and unfortunately, that one flaw (all of 0.25-0.5 dB) really held back the sound quality of the speakers while the family was here.  It took me all of 15 minutes to fix it by ear after they left.  I could try to explain it to them, but ... I guess what they heard was probably still way better than anything they normally get to hear.

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