HST18 / HS24

[lukeamdman]

Luke, are you saying only a 1000W amp is needed to power the HS-24 because of a 10 Hz shaped burst result with a Fi 18" driver?

 

No.

 

Speaking specifically to the CEA2010 burst tests, I think it's a common misconception that it requires a K10 or K20 to hit the numbers Josh did below 20hz. 

 

For example, I was trying to find out how much room gain I had at 10hz.  My original method was abysmal, and while asking another member on the proper way to do it, I was told I wouldn't reach Josh's numbers at 10hz since I didn't have a K10...

 

I've had several conversations with AVS members as well where similar things were said, so I'm not sure if many are looking at the voltages Josh needed to reach those CEA2010 numbers and just assume only mega amps can do it. 

[Bossobass Dave]

Due respect to the CEA fellas and Josh, but as I've said about 60 trillion times over the years, we use actual program source.

 

Here's a CEA 2010 10 Hz shaped tone burst followed by the Hulk punch, no change in MVL/SW trim:

 

 

The Hulk punch into dual HST-15s clocked 9,000 watts. The amp was an A-9K, so obviously was giving all the burst it had. Same result with a 5KW amp? 3KW? 1KW, or whatever the max CEA 10 Hz burst 2M GP test result takes?

 

There's just no comparison in the input signals. The (movie soundtrack clip) result would have been better with a bigger amp.

 

Wait... ain't you the guy who uses a bridged 6,000 watt amp to drive a ULF-Filtered horn???

[lukeamdman]

Due respect to the CEA fellas and Josh, but as I've said about 60 trillion times over the years, we use actual program source.

 

Here's a CEA 2010 10 Hz shaped tone burst followed by the Hulk punch, no change in MVL/SW trim:

 

 

The Hulk punch into dual HST-15s clocked 9,000 watts. The amp was an A-9K, so obviously was giving all the burst it had. Same result with a 5KW amp? 3KW? 1KW, or whatever the max CEA 10 Hz burst 2M GP test result takes?

 

There's just no comparison in the input signals. The (movie soundtrack clip) result would have been better with a bigger amp.

 

Wait... ain't you the guy who uses a bridged 6,000 watt amp to drive a ULF-Filtered horn???

 

 

I already said my comments were specific to CEA2010 burst numbers, hence I don't disagree with anything posted above. 

 

My horns are used for a specific frequency range and have a corner of 28hz, so not using a proper HPF would be idiotic.  I know you're not a fan of them since you've ripped on them more than once on these boards, but I have no doubt they'd put a smile on your face if you heard them, and I'm not talking about the aspect of SPL. 

[Bossobass Dave]

I already said my comments were specific to CEA2010 burst numbers, hence I don't disagree with anything posted above. 

 

My horns are used for a specific frequency range and have a corner of 28hz, so not using a proper HPF would be idiotic.  I know you're not a fan of them since you've ripped on them more than once on these boards, but I have no doubt they'd put a smile on your face if you heard them, and I'm not talking about the aspect of SPL. 

 

You misunderstood.

 

I have nothing against horns, passive radiator, ported, bandpass or other. Just sayin' that big power is required. And, big power repeated is required to make the popular habit of adding 6dB per doubling applicable. Otherwise, not. 8x24" is a waste of drivers if the power isn't added with them.

[SME]

I saw pics on the AVS forum of someone's staircase cracking and separating from the wall/house due to bass. I forget who it was, maybe N8dogg? I guess the larger your room and the more open it is, the less chances of destruction?

Do you have a link?

 

The chances of destruction depend on a lot of things, not the least of which is the SPL at the walls and corners at frequencies for which they are in heavy resonance, but in a smaller room it's definitely easier to hit higher SPLs.  As I understand it, structural damage is a very real concern with large scale bass systems (including pipe organs) in fairly large buildings such as churches and cathedrals.  Large stone and/or brick construction may exhibit narrow low frequency resonances that are not well damped at all, and unfortunately, they have very little ductility as compared to wood-frame construction.

[Ricci]

Using the HS-24, the 18dB potential increase in headroom over a single driver/amp system means eight PowerSoft K-20 amplifiers, eight dedicated 220V-50A home run outlets and eight HS-24 drivers, each in a proper size enclosure and placed perfectly in the room.

 

 a system that only cost  $60,000, with no signal shaping or EQ hardware.

 

What ???

 

You need a whole K20 on 240v with a dedicated circuit to run an HS-24?

 

I don't know...Seems like those "tiny" SP Torpedo 4kw plate amps did just fine one on one with the 24's. Maybe I was just drunk...

 

I'd be careful driving FOUR HS24's with a single K20. Advanced signal shaping is built in.

[lukeamdman]

Maybe I'm just crazy, but I'd like to see a head-to-head with 4 Raptors being powered by a A-14K (4ohm bridge) vs. the SP2-8000 (dual 2ohm).

 

The SP amp does cost more, but it has some advantages (silent and much more efficient). They're both 120v, too.   

 

 

EDIT: I know a few on here had a "bad experience" with that SP amp, but this comparison would certainly answer some questions. 

[Bossobass Dave]

What ???

 

You need a whole K20 on 240v with a dedicated circuit to run an HS-24?

 

I don't know...Seems like those "tiny" SP Torpedo 4kw plate amps did just fine one on one with the 24's. Maybe I was just drunk...

 

I'd be careful driving FOUR HS24's with a single K20. Advanced signal shaping is built in.

 

 

Hmmm. So, you have data we don't? Post it, please?

 

The HS-24 the plate amp drives is in a bit smaller box than your tests. Maybe it's time to test multiple drivers with various amplifiers. Well, we've been doing that for years, actually.

 

The point was, however, seemingly lost. I must really be getting bad at simple explanation.

 

If you use a single amp to run 4 vs one, you'll see a headroom increase of +6dB, no more, possibly less. THAT was the point.

[Bossobass Dave]

Maybe I'm just crazy, but I'd like to see a head-to-head with 4 Raptors being powered by a A-14K (4ohm bridge) vs. the SP2-8000 (dual 2ohm).

 

The SP amp does cost more, but it has some advantages (silent and much more efficient). They're both 120v, too.   

 

 

EDIT: I know a few on here had a "bad experience" with that SP amp, but this comparison would certainly answer some questions. 

 

You make too much of the GTG amp thing. It lingers because no solution to the problem was ever investigated or properly proposed by those with a vested interest.

 

Fork one over, I'll be glad to accommodate. Should be a 2dB difference in transient reproduction capability. I doubt there will be any surprises there. Your biases dictate your posts.

[lukeamdman]

You make too much of the GTG amp thing. It lingers because no solution to the problem was ever investigated or properly proposed by those with a vested interest.

 

Fork one over, I'll be glad to accommodate. Should be a 2dB difference in transient reproduction capability. I doubt there will be any surprises there. Your biases dictate your posts.

 

I only mentioned the GTG because I didn't want the SP amp dismissed because of that one experience.

 

I see this to be a comparison of two similarly powerful amps, each with some pros/cons on the other.  The A-14K is almost half the cost, but has audible fan noise, heavier, and less efficient.   The SP amp costs a lot more, but is silent, light weight, and more efficient.

 

What biases are you referring to?

[Bossobass Dave]

I only mentioned the GTG because I didn't want the SP amp dismissed because of that one experience.

 

I see this to be a comparison of two similarly powerful amps, each with some pros/cons on the other.  The A-14K is almost half the cost, but has audible fan noise, heavier, and less efficient.   The SP amp costs a lot more, but is silent, light weight, and more efficient.

 

What biases are you referring to?

 

The 'everything-I-buy-is-better' bias. That's an observation from our forum discussions, FWIW. No dis intended, just an observation.

 

I don't recall anyone ever dismissing the SpeakerPower products in any way. If that happened, I'm just not aware of it.

 

What bothered me was Seaton's comments when it was first mentioned in Brandon's GTG thread. He dismissed the problem as line sag. Well, those of us who were there know that wasn't probable and if it were, do the amps come with a noted mains requirement?

 

Blah, blah, blah. I thought it was water under the bridge, but a still unresolved situation.

 

Efficiency is a good thing. But, the difference between 60% and 90% is 50%. That translates to fan noise and nothing else. I've run my amplifiers for over 5 years in their intended app. Can you cite anyone who employs a 10dB L/T and runs a SP amp to its limits for that long? That's really what determines if efficiency was sufficient to forgo overkill cooling methods in the intended app.

 

Otherwise, what matters is performance. Size is the same. Weight is irrelevant.

[lilmike]

I imagine everyone is engaging in humorous hyperbole here, but just in case...

 

One driver (doesn't matter which), driven by an amplifier that is capable of pushing the system to it's limit, plus some headroom equals 'x'.

 

Add another driver so that you now have 2 of them and that equals 'x' plus 3dB. It will equal 'x' plus 6dB if you also add a second identical amplifier, assuming proper mains for 2 amps and proper placement in the room that results in only constructive reflections across the system's bandwidth (not likely, but we're playing around with numbers here).

 

Now, add two more drivers so that we have 4 identical drivers in identical boxes and that equals 'x' plus 6dB. Again, go to 4 identical amplifiers with proper mains and the system gives an added 12dB.

 

Double the driver/box count again and assume perfectly harmonious placement and you have 8 identical passive subs that potentially equal 'x' plus 9dB. Go to 8 identical amplifiers, each on proper mains, and you have 'x' plus 18dB.

 

Using the HS-24, the 18dB potential increase in headroom over a single driver/amp system means eight PowerSoft K-20 amplifiers, eight dedicated 220V-50A home run outlets and eight HS-24 drivers, each in a proper size enclosure and placed perfectly in the room.

 

If a single version of this system has a max top end of 126dB at 30 Hz, where room gain begins, and there are zero destructive reflections from eight of them in-room, you have headroom to 144dB from a system that only cost  $60,000, with no signal shaping or EQ hardware.

 

Yes... very likely.

 

If that last line is sarcasm, I get it. If not, I have no idea WTF you're talking about.

 

K20 vs HS24 = smoked HS24. Period. Truth be told, it doesn't take nearly that much power to cook a 1500W coil. 

 

Simply put, no matter what someone read somewhere on the Internet, dumping 18 KW into a 1.5 KW rated driver isn't gonna end well, no matter what sort of advanced secret sauce signal shaping gets applied. Don't care if it is in a sealed box, and "excursion" is controlled, cause, it isn't. Seriously, when that much power (12X rated RMS) gets applied, the moving parts will happily slam into the stationary ones. The mechanical limits are exceeded long before you get below 30 Hz, let alone 3 Hz. In addition, there is this thing called a thermal limit, and that limit was quite clearly defined to be a point that's less than 2.677X RMS rated power using FAR more modest amps (and then confirmed three more times). 

 

The point you were trying to make (which, after I re-read your posts, actually seems to be valid - in a nutshell, it takes a LOT of power and a lot of drivers to make big SPL) simply got lost in the fact that you're asking a driver (no matter how badass you think it is) to vastly exceed its capability. History has shown us that the smoke comes out when that happens. Once it clanks or stanks, the party's over. 

 

Big sub amp power is great, I am in that club. Not quite among the elite players, but I am not power-limited. I am learning that with big power, the driver limits come in to play that much faster. As you ramp things up, each 6 dB increase means double the throw. Each 6 dB also doubles the voltage, which, if the amplifier can manage to supply it, means power (and heat into the coil) is quadrupled.

 

Limits will be found, and it won't end well (or cheaply).

 

If anyone gets this, you do Bosso. You got that T-shirt so long ago it is worn out.

 

The point you were trying to make simply got lost in the silliness that somehow a 1500 watt rated driver will soak up 18 KW. 

 

It won't, at least, not for long.

[Bossobass Dave]

Yes, power in the wrong hands is not good. That goes without saying.

 

Hopefully, we don't have to address the obvious from here out?

 

The point of my post was in reaction to the "OMFG!!!! YOU HAVE 8 OF THOSE??? YOU MANIAC, UR HOUSE WILL COLLAPSE!!!

 

If you buy 8 HS-24 and power them with a single Behringer amplifier, you might gain 6dB over a single driver, if any gain is measured.

 

Regarding cooking the VC with 1500W, or whatever it was you were trying to say, what am I missing in the following graphic that shows 33,000 watts being utilized in half of bandwidth of the CEA 2010 regimen on a single HS-24?

 

 

IOW, Josh dumped the entire amplifier into the driver and it still was an amp-limited result. If he intends to mean that the result is misleading, there should be some disclaimer o that effect with corrected max SPL numbers.

 

Real input source requires a LOT of power. Let me repeat...

 

We dumped 9,000 watts into 2 HST-15s during playback of a single movie soundtrack clip... repeatedly. First, to measure the amplifier output, second, to measure the drivers excursion and third, to measure the accuracy in the in-room reproduction. At no point was the VC in danger. We graphed the SpecLab comparison result, the O-scope result, the amp measured voltage and current output results and measured excursion result with videos.

[lilmike]

Patronizing condescension is patronizing condescension.

 

Whatever.

 

No point going further with this, sorry to interrupt your SI lovefest.

[lukeamdman]

The 'everything-I-buy-is-better' bias. That's an observation from our forum discussions, FWIW. No dis intended, just an observation.

 

I don't recall anyone ever dismissing the SpeakerPower products in any way. If that happened, I'm just not aware of it.

 

What bothered me was Seaton's comments when it was first mentioned in Brandon's GTG thread. He dismissed the problem as line sag. Well, those of us who were there know that wasn't probable and if it were, do the amps come with a noted mains requirement?

 

Blah, blah, blah. I thought it was water under the bridge, but a still unresolved situation.

 

Efficiency is a good thing. But, the difference between 60% and 90% is 50%. That translates to fan noise and nothing else. I've run my amplifiers for over 5 years in their intended app. Can you cite anyone who employs a 10dB L/T and runs a SP amp to its limits for that long? That's really what determines if efficiency was sufficient to forgo overkill cooling methods in the intended app.

 

Otherwise, what matters is performance. Size is the same. Weight is irrelevant.

 

My intention wasn't at all to bring up those aspects the GTG, so forget I said it. 

 

I don't agree with your observation that I'm biased.  I'm a simple hobbyist who has no stock in any of this.  Can you say the same?  Good luck with that. 

[Bossobass Dave]

 

 

Patronizing condescension is patronizing condescension.

 

Whatever.

 

No point going further with this, sorry to interrupt your SI lovefest.

 

 

After wondering WTF I'm talking about, you said this:

 

K20 vs HS24 = smoked HS24. Period. Truth be told, it doesn't take nearly that much power to cook a 1500W coil.

 

 

Well, sorry, it should be obvious to even a casual observer of Josh's test results that it takes every bit of a K-20 to post the same results. It's not my intention to post recipes on how to cook an HS-24, or any other driver. It's patronizing condescension to infer I ever did. I've routinely coupled more than 1500W with far less power handling capable drivers, many, many times. I have NEVER "smoked" a VC.

 

Then, there's this:

 

The point you were trying to make simply got lost in the silliness that somehow a 1500 watt rated driver will soak up 18 KW.

 

 

Yeah, silliness. Let's see, 400V? @ 50 Hz into 5 ohms = 32,000 watts, and the amp ran out of gas. Was the VC "Smoked, period"? How silly is that? Let's see, what would the result have been if Josh used 1500W? Around 115dB? That changes the result a bit.

 

Is Dave Gage insane to couple the driver with a 4,000 watts, continuous capable amp, or do you approve of 6dB less headroom than your smoked level?

 

The condescension I suffer is from people like yourself who seem to think they understand every aspect of a sealed subwoofer system to such an extent that what I post on the subject is error wrapped in silliness and sarcasm.

 

"...SI lovefest".

 

 

If you prefer to wonder out loud WTF I'm talking about through the silliness of my SI lovefest posts, expect some condescension.

[lilmike]

OK, last post on this, then I'm stepping away.

 

I may not be an elder statesman, but I have been exploring the performance and limits of subwoofers in all sorts of different cabinets for better than three decades now. I do have a pretty sound understanding of "big power" and driver limits. I have burned coils. I have bent formers. I have torn cones, spiders, and surrounds.  

 

The CEA2010 limit is simply ONE of many things that Josh measures and posts. No matter what those particular limits turn out to be, the remainder of the driver's limits all still apply, and the lowest one of them is the one that MUST be honored, or things start to stank and clank when the driver passes that point. Can't pick the biggest numbers and forget the rest, it just won't end well.

 

Don't get me wrong, Nick's drivers don't suck. I have nothing against Nick or any of his products. I personally don't have a spot where I can use the driver being discussed, but several of his other drivers may work for me. I just disagree with your assertion that a 1500W driver can handle 18KW, or 33KW for any amount of time.

 

They're not magical. The laws of physics and basic fundamentals of materials science all still apply. Your claims that they'll somehow hold up to 22X their rated RMS by cherry-picking numbers you grabbed off the Internet while ignoring the rest of the real limits that all remain in play?? That's just utter crap, and you know it. Your comment takes Josh's measurement out of context and grossly misrepresents the capability of Nick's driver as a result. It doesn't need to be misrepresented...it is a damn capable driver.

 

Nick's the one that designed and built it, and he rates it at 1500 watts RMS. 

 

I'll bow out now, I have no wish to pick a fight on the Internet about a driver I'll never own. I've evidently ruffled enough feathers already, and I see no reason to muddy up this thread any further.

 

Dave, odds are that we agree about a whole lot more than we disagree about. Sorry if I upset you, I'll move on now. Peace.

[chrapladm]

I am a bit confused why everyone is confused. It just seems to me that if you want the maximum out of a driver your going to need big power. If you want to add more drivers then it is best you add another amp. SO I dont think Bosso was saying you have to have a K20 per HS24 but using this amp does get it to its max potential. Then as we all know you have to add from there to get the full 24db gain in a perfect scenario.

 

Some people will use an Inuke for their power and thats fine also. Buy what you can afford. SP amp, A14K or Inuke. We all know what we can afford and what to expect.

[dgage]

What I read was essentially, 8 HS24s will be great IF(!!!) you give them the requisite power.  A super big amp was brought up only to power the multitude of HS24s being discussed, not for a single HS24.  It is completely possible to burn up an HS24 with 4,000w as I have done it.  I wouldn't recommend a DIYer use 4,000w or more into a single HS24.  The only reason I do it is because I wanted an uber commercial subwoofer and if a customer burns up a driver with my 4,000w amp then I will replace their driver.  A DIYer does not get that type of warranty with anything more than 1500w.

[mlah384]

I was under the impression that the HS24's 1500w rating was conservative for warranty purposes? That it actually would handle double that continuously? Especially for theater purposes...

[Electrodynamic]

3,000 continuously? The BHS-24.

[chrapladm]

Thats why these systems are designed with people who have experience and knowledge. I have the potential for 1500watts peak power going to my line arrays that are about 80watts RMS. I have never hurt any of the VC's on them but would never go to a 150watt amp either.

 

If your really worried about it buy a smaller subwoofer to play with and then go from there.

[Leons]

hello all..

 

regarding max spl and such.. i'm a junkie I admit, however.. what i'm after is effortles

super clean infrasound with no hint of any distorting or strain... even when driven loud it

should sound like it's on idle.. so those last few db's.. are cool.. but its those las few (clean) db's

i'm after..

 

regarding mains, i have a dedicated 110A 220V line.. that will do the trick..

 

Regarding amps.. I start with 2 fp14000 clones.. one channel per 2 hs24 and see

what happens...if it is not enough I buy 2 more... one channel per hs24 but that does

seem on the edge to mee... dependant on program material ofcourse..

I don't have budget for eight K20's but hell yes, these obviously are monster amps!

 

regarding progress.. this was a crazy week at work so i did not check what's happening at the

woodshop.. however the aluminum flanges and port stops arrived today.. vent ducting also. I will

bring these to the shop tomorrow... i hope they surprise me..

 

Best regards,

L.

[dgage]

Leons, what voice coil configuration did you get for your HS24s?

 

I'm just going to caution you to say 4,600w to a single HS24 is potentially asking for trouble, mainly in the form of a burnt voice coil.  End of Tomorrow, Lone Survivor are just a few of the recent movies with low, repetitive sine waves that have the potential to burn up a subwoofer driver quickly.  If you do go with 4,600w, carefully choose your demo material if you want to show off your system.  Don't use something like the Lone Survivor Chopper scene with repetitive 6/12/18Hz sine waves.

[Ricci]

Hmmm. So, you have data we don't? Post it, please?

 

The HS-24 the plate amp drives is in a bit smaller box than your tests. Maybe it's time to test multiple drivers with various amplifiers. Well, we've been doing that for years, actually.

 

The point was, however, seemingly lost. I must really be getting bad at simple explanation.

 

If you use a single amp to run 4 vs one, you'll see a headroom increase of +6dB, no more, possibly less. THAT was the point.

All the data is there. It's the interpretation of the data that seems to be different. Of course I have a lot of stuff that never makes it public.

 

Burst data at 50Hz is just that. What does that have to do with long term power applied or excursion down in the sub bass region? It's the first, lowest level limitation encountered that matters, not the highest found from one specific very limited test. For the 24 in the box tested that limitation was about 100v during a full band sweep. That's roughly 2000w into a 5ohm impedance. It was pushed a little harder to 130v at 10Hz with the short burst signal which is roughly 3400w. If we use a smaller box like Dgage to limit excursion below 20Hz, you can perhaps bump up to roughly 165v which is putting the driver at xmech in the 25-30Hz range. That's around 5.5kw rating worth of amplifier. That's already over 3x what the driver is rated at long term and dangerous if left unchecked. So depending on the enclosure volume and how long the system will be run hard, an amp rated at 1500-5000 makes sense. One of the big boy amps I just mentioned will easily get all there is worth using from 4 of the 24's and you'd need to be careful with some sine wave like content. The driver is the limitation not the amp. That being the case there's plenty of reserve in the amp to get the full 12dB from 1 to 4 drivers.

 

I've also ran through a lot of amps on multiple sealed drivers with boost. Probably not as many but more than my share.