(8) Sealed Incriminator Audio Judge 21" build

[BeastAudio]

Ahh, the power of sealed subs.

 

 

More like, Ah the power of slab basements..... So Luke, when's the time to bring up some type of nearfield placement of a few more drivers in your space? Too soon? You certainly seemed to like the effect of mine in my space.

[Shredhead]

 

According to the data, Nick is correct, IMO. Severely clipped input signal. Not clipped signal at all

 

Worse than I've ever seen.

 

I'm sure you've seen worse

 

Had anyone been paying attention to the SpecLab caps after the first incident, the problem would have likely stopped there.

 

Your son, Paul, was monitoring the Speclab in realtime when the incident happened. He was just as confused as everybody else was at the time. So, no. Nobody would have stopped it from happening.

 

Had anyone been paying attention to the SL mic'd that was familiar with the SL digital for using that scene as a demo is what he meant.  That was the first time that I've ever seen any part of that movie so I was pretty much in the dark.  Since then, I've analyzed the whole movie and I believe that it's soundtrack was mixed very poorly.  The studio had no software for monitoring levels (or a playback system that could reproduce) sub 20Hz so they should have been experienced enough to put a filter on the heli track.  http://data-bass.ipbhost.com/index.php?/topic/425-analyzing-waveforms-of-heavy-hitting-movies/?p=11801

 

The scene in question is -3.43dB from a WCS.  I measured Beast's AVR at the GTG and it clips the sub out on WCS's when they are attenuated by less that 10dB.  As Beast just said "I will point out in further testing that at the levels we were nearing at the g2g was likely ref, with a +10dB boost on the LFE channel, and then gage subsequently bumped the gain on the sub another 3-5dB."

 

The AVR's sub out to the torpedo amp was probably nearing 10dB into clipping.  That is pretty hard clipped in itself but the amp more likely than not added to that.  Anyone here know how the SP torpedo's front end would handle a signal like that?  What about pushing the gain on the amp 3-5dB on top of that input signal?  Nobody here knows exactly what kind of signal that amp was outputting but it's a pretty safe guess to assume that it looked like binary.  I'm sure I don't have to explain to the guys in this thread what that does to RMS heat to the coil.  Gage wanted to push his stuff hard at the GTG and aside from the toxic fumes, I thought it was pretty epic. 

 

Back on track: Luke, have you tested your SP12k on all 8 yet at full output and that's why you are leaning towards getting another 12k?  I would guess with the deep, low extended sine wave content you enjoy listening to, 3k per driver might be a bit dangerous.  Like you said,

"It doesn't take 4kw of clipped power for a full minute to fry a rugged and well designed/built driver.  4kw of clean power for the same minute will do that job just fine."

The difference between 3k and 4k is only 1.2dB.

[tuxedocivic]

Only 1.2db, but a whole lotta heat

[lukeamdman]

More like, Ah the power of slab basements..... So Luke, when's the time to bring up some type of nearfield placement of a few more drivers in your space? Too soon? You certainly seemed to like the effect of mine in my space.

 

Too soon!!!  lol

 

Yeah those near-field HSTs instantly put a grin on my face.  Automatic response, I couldn't help it.

 

It's not completely off the table, but the last time I measured the space was so limited I didn't think it could be done with something as big as an 18" driver. 

[lukeamdman]

Had anyone been paying attention to the SL mic'd that was familiar with the SL digital for using that scene as a demo is what he meant.  That was the first time that I've ever seen any part of that movie so I was pretty much in the dark.  Since then, I've analyzed the whole movie and I believe that it's soundtrack was mixed very poorly.  The studio had no software for monitoring levels (or a playback system that could reproduce) sub 20Hz so they should have been experienced enough to put a filter on the heli track.  http://data-bass.ipbhost.com/index.php?/topic/425-analyzing-waveforms-of-heavy-hitting-movies/?p=11801

 

The scene in question is -3.43dB from a WCS.  I measured Beast's AVR at the GTG and it clips the sub out on WCS's when they are attenuated by less that 10dB.  As Beast just said "I will point out in further testing that at the levels we were nearing at the g2g was likely ref, with a +10dB boost on the LFE channel, and then gage subsequently bumped the gain on the sub another 3-5dB."

 

The AVR's sub out to the torpedo amp was probably nearing 10dB into clipping.  That is pretty hard clipped in itself but the amp more likely than not added to that.  Anyone here know how the SP torpedo's front end would handle a signal like that?  What about pushing the gain on the amp 3-5dB on top of that input signal?  Nobody here knows exactly what kind of signal that amp was outputting but it's a pretty safe guess to assume that it looked like binary.  I'm sure I don't have to explain to the guys in this thread what that does to RMS heat to the coil.  Gage wanted to push his stuff hard at the GTG and aside from the toxic fumes, I thought it was pretty epic. 

 

Back on track: Luke, have you tested your SP12k on all 8 yet at full output and that's why you are leaning towards getting another 12k?  I would guess with the deep, low extended sine wave content you enjoy listening to, 3k per driver might be a bit dangerous.  Like you said,

"It doesn't take 4kw of clipped power for a full minute to fry a rugged and well designed/built driver.  4kw of clean power for the same minute will do that job just fine."

The difference between 3k and 4k is only 1.2dB.

 

LOL!  That one got me. 

 

The "problem" I have right now is a max of only ~1,200-1,300w per driver tops, and let's face it, by 10hz and lower there's no way that CC5500 is outputting anything near 5kw for any useable length of time, so each driver is likely getting less than 1kw by then.  For my listening tastes, and also considering the extra power demand of transients that been brought up recently, these subs are being severely held back down low from their potential.  I will say though, for 25hz+ music content, the CC5500s bring them to dizzying levels just fine, so I don't need any extra power there.

 

Of course the SP2-12K isn't immune to this either, as I think I recall Brian posting on AVS years ago that at 20hz it can output 6kw, but by 12hz it was down to ~4.8kw or something near there. 

 

I think a pair of SP2-12K will require thorough testing and restraint, but I'm not the type to go guns blazing into content I'm not familiar with. 

[SME]

Not to beat the dead horse, but according to here the long term output of the SP1-4k is only 2250W/2 ohm.  Anyway, I also agree that it's not a big deal that some drivers got fried at a GTG, and for probably any driver, the difference between 2250W and 4000W is only a matter of time, and time was against these drivers. 

[Shredhead]

The "problem" I have right now is a max of only ~1,200-1,300w per driver tops, and let's face it, by 10hz and lower there's no way that CC5500 is outputting anything near 5kw for any useable length of time,

 

Of course the SP2-12K isn't immune to this either, as I think I recall Brian posting on AVS years ago that at 20hz it can output 6kw, but by 12hz it was down to ~4.8kw or something near there. 

 

I think a pair of SP2-12K will require thorough testing and restraint, but I'm not the type to go guns blazing into content I'm not familiar with. 

You have the impedance graph.  Test the voltage to the cabs with each amp at 10Hz and you can tell us how much power your distributing with your current options.

 

Measure the excursion of the driver with the amp that wins that test to see how much there would be to gain with an additional sp12k.

[lukeamdman]

You have the impedance graph.  Test the voltage to the cabs with each amp at 10Hz and you can tell us how much power your distributing with your current options.

 

Measure the excursion of the driver with the amp that wins that test to see how much there would be to gain with an additional sp12k.

 

I plan on taking it a step even further.  With my new amp testing rig, I'll know the voltage and current at any output level    

 

No more guessing games with how much change there is in resistance as power goes up. 

[Infrasonic]

Had anyone been paying attention to the SL mic'd that was familiar with the SL digital for using that scene as a demo is what he meant.  That was the first time that I've ever seen any part of that movie so I was pretty much in the dark.  Since then, I've analyzed the whole movie and I believe that it's soundtrack was mixed very poorly.  The studio had no software for monitoring levels (or a playback system that could reproduce) sub 20Hz so they should have been experienced enough to put a filter on the heli track.  http://data-bass.ipbhost.com/index.php?/topic/425-analyzing-waveforms-of-heavy-hitting-movies/?p=11801

 

The scene in question is -3.43dB from a WCS.  I measured Beast's AVR at the GTG and it clips the sub out on WCS's when they are attenuated by less that 10dB.  As Beast just said "I will point out in further testing that at the levels we were nearing at the g2g was likely ref, with a +10dB boost on the LFE channel, and then gage subsequently bumped the gain on the sub another 3-5dB."

 

The AVR's sub out to the torpedo amp was probably nearing 10dB into clipping.  That is pretty hard clipped in itself but the amp more likely than not added to that.  Anyone here know how the SP torpedo's front end would handle a signal like that?  What about pushing the gain on the amp 3-5dB on top of that input signal?  Nobody here knows exactly what kind of signal that amp was outputting but it's a pretty safe guess to assume that it looked like binary.  I'm sure I don't have to explain to the guys in this thread what that does to RMS heat to the coil.  Gage wanted to push his stuff hard at the GTG and aside from the toxic fumes, I thought it was pretty epic. 

 

Back on track: Luke, have you tested your SP12k on all 8 yet at full output and that's why you are leaning towards getting another 12k?  I would guess with the deep, low extended sine wave content you enjoy listening to, 3k per driver might be a bit dangerous.  Like you said,

"It doesn't take 4kw of clipped power for a full minute to fry a rugged and well designed/built driver.  4kw of clean power for the same minute will do that job just fine."

The difference between 3k and 4k is only 1.2dB.

 

Thanks, Paul, for chiming in.

 

It sure sounds great on paper that this could have been the list of things that lead to the failure but I'm not so sure. The produced output from the M24 was super clean the whole time until it ....well. I've heard everything from mild to brutal clipping and I seriously doubt that is what happened at the GTG. It was a simple combination of too much power applied with signal content that is not forgiving in the slightest.

 

 

Too soon!!!  lol

 

Yeah those near-field HSTs instantly put a grin on my face.  Automatic response, I couldn't help it.

 

It's not completely off the table, but the last time I measured the space was so limited I didn't think it could be done with something as big as an 18" driver. 

 

There is a an app subwoofer riser for that.

[SME]

Thanks, Paul, for chiming in.

 

It sure sounds great on paper that this could have been the list of things that lead to the failure but I'm not so sure. The produced output from the M24 was super clean the whole time until it ....well. I've heard everything from mild to brutal clipping and I seriously doubt that is what happened at the GTG. It was a simple combination of too much power applied with signal content that is not forgiving in the slightest.

 

Is it possible that the output sounded clean because the current limiter circuit on the amp was engaged?  As I posted above, it looks like the SP1-4k tops out at 2250W/2 ohm long term, so if it really was being overdriven by a continuous signal, then it's likely that limiter was active for a good bit of it.  And of course, I've seen plenty of people argue here already that 2250W is enough to blow out any driver if it's applied for long enough.  A larger question is what the limiter sounds like.  I'd guess that it adds some low-order harmonic distortion but not so much high order HD.  Then there's the complication of the room transfer function and the fact that it tends to diminish low-order ULF HD in-room.  Without the higher order distortion, you wouldn't necessarily hear signs it was being over-driven.

[Infrasonic]

No limiter was engaged which is what lead to the failure in the first place.

[maxmercy]

Shred brings up a very important point.

 

The 3 AVRs I have tested cannot handle a WCS with trims set at 0 and MV at -0dB.  For the Denon/Marantz Units I have measured and others have, you need to attenuate the SubOut to -10dB (or -10.5dB to be safe) to output unclipped waveforms of a near WCS (all channels in phase with same signal at -0.1dB) with bass management engaged at MV -0dB.

 

Everyone that listens with SubOut at 0 or + levels is asking for a clipped signal.  SubOut at '0' running at MV -0dB =REF means a bass managed signal at -10dB form a WCS will clip.  That means EoT, Lone Survivor, HTTYD all will clip when run at MV -0dB = REF.  So many folks here run with subs at + 'something-or-other' at or above MV -0dB = REF, and do not know that they are corrupting the signal sent to the subs.  

 

If you want a clean sub signal and want to run hot, turn your SubOut level down and use the amplifier attenuators to set the amount of dB 'hot', or restructure everything so that MV -10dB = REF with trims at 0 or below.

 

For the LF-heavy content we like on this site, do not let the weakest link in the chain destroy the signal.

 

For these helicopter scenes that have a strong fundamental and tons of harmonics, distortion/clipping is likely masked to a very large extent, so the system may 'sound good', until you playback the material without the AVR clipping the hell out of the SubOut.  I wager most people that listen above reference with the subs hot (all controlled by their AVR) may have never heard a clean presentation on the louder portions of films/trailers.

 

For really powerful low end, the limiting factor can be the AVR if you have a capable system, unless you set up the gain structure properly taking into account the AVR's limitations.

 

I would like to see the AVR manufacturers take bass management signal integrity and headroom into account, because they obviously don't at this point.

 

 

JSS

[EndersShadow]

Shred brings up a very important point.

 

The 3 AVRs I have tested cannot handle a WCS with trims set at 0 and MV at -0dB.  For the Denon/Marantz Units I have measured and others have, you need to attenuate the SubOut to -10dB (or -10.5dB to be safe) to output unclipped waveforms of a near WCS (all channels in phase with same signal at -0.1dB) with bass management engaged at MV -0dB.

 

Everyone that listens with SubOut at 0 or + levels is asking for a clipped signal.  SubOut at '0' running at MV -0dB =REF means a bass managed signal at -10dB form a WCS will clip.  That means EoT, Lone Survivor, HTTYD all will clip when run at MV -0dB = REF.  So many folks here run with subs at + 'something-or-other' at or above MV -0dB = REF, and do not know that they are corrupting the signal sent to the subs.  

 

If you want a clean sub signal and want to run hot, turn your SubOut level down and use the amplifier attenuators to set the amount of dB 'hot', or restructure everything so that MV -10dB = REF with trims at 0 or below.

 

For the LF-heavy content we like on this site, do not let the weakest link in the chain destroy the signal.

 

For these helicopter scenes that have a strong fundamental and tons of harmonics, distortion/clipping is likely masked to a very large extent, so the system may 'sound good', until you playback the material without the AVR clipping the hell out of the SubOut.  I wager most people that listen above reference with the subs hot (all controlled by their AVR) may have never heard a clean presentation on the louder portions of films/trailers.

 

For really powerful low end, the limiting factor can be the AVR if you have a capable system, unless you set up the gain structure properly taking into account the AVR's limitations.

 

I would like to see the AVR manufacturers take bass management signal integrity and headroom into account, because they obviously don't at this point.

 

 

JSS

 

So for a dummy like me that has trouble reading all the technical stuff, are you saying I should have my sub level at -10 give or take, and then adjust the gain up accordingly to offset the signal being lowered from the AVR?

 

I've got a Denon X4100a and I think the sub is like -4.5 right now and I'm powering my DIY Sub (4 cubic foot ported Cube15 from DIYSoundgroup w a HT-15) with one of the Dayton SA1000 rackmount amps.

 

Just trying to make sure I'm not screwing something up in my chain as you mentioned.

[Infrasonic]

Should have bought a Yamaha.

[Bossobass Dave]

...

[Infrasonic]

Well... that was a useful response. Thanks, Dave.

 

So if you said the same, it would be okay and "correct"?

[Bossobass Dave]

...

[Infrasonic]

Fuck this.

[Infrasonic]

Dude, your posts on this subject are hilarious. Own it.

 

Can you quote me pontificating how clean a sub is reproducing a soundtrack without data?

 

The M24 was producing triple digit harmonic distortion as well as harmonics that have no relation to the soundtrack content. The Q is; what caused it. You have zero clue, obviously. I'm reacting to your "explanations", that's all.

 

 

Whatever.

 

Triple digit HD my ass. You weren't even in the room when it happened.

[Bossobass Dave]

...

[Bossobass Dave]

...

[Bossobass Dave]

...

[lukeamdman]

Funny. If reality makes you cry, then, sure, go ahead. I think both of you could have saved some $$ and gotten better results. Don't shit yourself over it. It's just an opinion, based on experience and the facts of the matter.

 

 

 

 

 

Golly. Please show me where the word "distortion" appears in my post? It doesn't. You're using a +10dB signal boost to get the high Fs driver to a flat response at the seats. With the HS24, you would need NO signal boost to get the same result. That has nothing to do with distortion. It's just a fact and not a trivial one. I apologize for mentioning it, but you were hinting that you selected the IA driver over the SI driver because it's somehow more reliable. With 10X power for same response, it is not.

 

You've thrown that Fi driver under the bus several times because it couldn't reach a passing result at 10hz under CEA-2010 standards.  Why couldn't it produce a passing result, Dave?  Distortion.  I think that's why you compared my drivers to it specifically. 

 

You completely ignored that I showed the Fi and HST have nearly identical raw responses, and my subs also share a very similar response to them.  If my subs need 10db of a LT for a flat response, so does the HST (which you sell in your Raven's).  You'd be saying this same stuff and trashing my decisions if I had chose HSTs? 

 

You also ignored how two drivers, one with a Fs of 25hz and the other with 21hz, showed pretty much identical performance. 

 

You've also said that the HS24 has more displacement than the 21" IA.  Who on here doesn't understand that 24" driver has more surface area than a 21" driver?

 

All I said is that after my research, which I admitted could be of course be flawed, is that I'd personally give an edge in durability to the Judge over the HS24.  Am I not free to research and make purchasing decisions off the information I find?  If you can't handle such a tame comment about a product you don't even own than I don't know what to tell you.

 

I had goals for this project and I met them.  The HS24 didn't fit the bill for a variety of reasons, and why you care so much as to trash my thread over it I'm lost. 

 

I don't go into your threads trashing your products and projects, so please have the same courtesy for me.

[lukeamdman]

With the HS24, you would need NO signal boost to get the same result. That has nothing to do with distortion. It's just a fact and not a trivial one.

 

I have a really hard time believing the HS24 is flat to 5-6hz without any signal shaping, but since I have no personal experience with this sub, who am I to say.

 

Dave Gage, you have more experience with this sub in real world use than anyone I can think of.  If what Dave says is true, why are/were you boosting the low end?

 

EDIT:  That second question was intended for Dgage

[dgage]

I have a really hard time believing the HS24 is flat to 5-6hz without any signal shaping, but since I have no personal experience with this sub, who am I to say.

 

Dave, you have more experience with this sub in real world use than anyone I can think of.  If what Dave says is true, why are/were you boosting the low end?

Too many Daves here but I'm going to assume me for this question.  Honestly...marketing.  I'm using a big driver in a relatively small enclosure although the BHS24 driver works better in the small enclosure design than the HS24.  I knew with that design that I'd have to boost the low-end to get stronger low end response from the smaller enclosure.  But frankly, much of the boost is there to make the middle of the field measurement look better.  Did I push it some?  Maybe, likely.  The alternative is that the graphs from the Mariana 24 not look as impressive as compared to other company's DSP'd subs even though in-room and high output would likely be much stronger with the Mariana 24.  That's a whole other can of worms that I didn't want to deal with as most consumers researching subs really don't understand how much the room reinforces and shapes low-end output, they compare graphs and they compare numbers.  Then again, the in-room response with the Mariana 24s has been flat down to 7Hz before it starts rolling off.  This has been in several rooms.  The question is, what would that response have been like without the low end boosted?  Good question and I'd have to measure multiple rooms before I could answer that one reliably.

 

I may have to take a separate tact by showing in-room response graphs, which are more representative of real-world, instead of middle of the field measurements.  Again, this is more of a marketing issue and I am sort of am mad at myself for getting caught up in it.  But I've seen really good products marketed poorly and really poor products marketed well.  Just like engineering, everything is a balance and I want to stay balanced here too.  But I definitely don't want to ever, ever be caught up in anything deceitful or misleading...I'd rather fail at business.