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General max spl point FR from our more traditional offerings location

2189 Views 41 Replies 10 Participants Last post by  audiovideoholic
Ok, I have been trying to determine where the max and/or continuous spl calculation is located at on some if not most of our preferred manufacturer's products is located.


When I say our preferred I'm referring to Jtr, danley, seaton, and seos designs.


Most accurate FR ratings normally say something along the lines of +3/-3 db thru "x" hz-"x"hz. Well that leaves 6 dbs on the table and gives the consumer no idea where the variations occur.


The manufacturers that I mentioned use pro-audio bass drivers in their designs and sometimes in multiples. So where is this max continuous db mark located in most loudspeakers? Is it in the bass drivers FR, MR FR, or in the cd/horn FR?


I'm "just" educated enough to understand that a smooth/flat FR is better suited for most speakers but there has to be a point where the FR is either up 6db or down 6 db if the stats show a sweep from say 60hz-18khz is +3db/-3dbrated for max/continuous output of 133db within said FR.


So since none of these full range speakers use terminals for each seperate section, how does one know where that max/continuous spl lies upon the total FR without a "max" spl graph?


I was first thinking that the speakers that used multi 10"-12/15" drivers, the max/continuous numbers came from the bass drivers, but is that a realistic assumption? I know a flat FR is what is most desirable but the numbers have to come from somewhere.


This leads me to my next point of emphasis. +3/-3 db might not seem like much but when the spl levels are reaching 130-135db, each 3 db is truly a huge step up in loudness so have wanted to learn a little more about the general ratings. From some quick googlings I found data that seemed to suggest the ratings are in the 2k-3khz range. Does this seem realistic?


All this stems from ipgraditus which many of you understand. The main point in general is the danley SH-50 vs the other two higher output loudspeakers: SH-64 or SH96HO. Really trying to understand what the difference in spl will be throughout the entire spectrum. I have well over 140db of bass that will need to be matched and would hate a speaker that is rated at say 142db max to only be in one octave.


Back in my car audio days I was hitting 155+dbs at idle but I also had 18+ mids/highs that could "clearly" be heard and felt with all the subs. I know car audio and ht are completely different but not only did I set KY spl records back in the 90's, I was also the only one that had the mids/highs to make it sound superdupperiffic! And that was a serious statement. I had about as much money invested in my door panels/mids/highs/EQ/etc as I did in my batteries/amps/subs/caps/altinators/power wire distribution etc...


I just want to do better than keep up with 145+db bass in my ht!!!


A total overhaul is in store!
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wow...


your observation is astute. most manufacturers don't provide that data. what you want, of course, is a simple request: frequency response every 5db until the speakers crap out. this way you could see where and how that happens.


even better would be response and distortion every 5db until the speakers crap out.


BUT, what company in their right mind would provide such information? answer: none.


so what to do?


short of actual measurements, the best you can do is probably model it up, make some assumptions, and...guess.


the good driver manufacturers can actually give a pretty good idea. such will often show frequency response, then a power rating with a description of the conditions, such as 18sound does for the 15nd930

"Program power rating is measured in 125 lt enclosure tuned at 50Hz using a 40-400Hz band limited pink noise test signal with 50% duty cycle applied for 2 hours."


combined with the power compression numbers and, well, you get the idea.


it at least that helps with the guess. :)


it isn't completely surprising, as raw pro-audio drivers are marketed to engineers or quasi-engineers, while the speakers themselves are marketed to the g.p.
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Well....you could make a reasonable assumption that the -3 dB points are going to be at the ends of the FR curve since the woofer and tweeter eventually give up. The +3 dB point may be much harder to find since a 3 dB peak might might sound quite nasty depending on where you find it...like horn honk. So the better designs probably focus on getting rid of the annoying peaks which is why you might see +1dB/-3dB used as a specification. So the peak SPL should be over a broad range and not just one octave...and active equalization would be used to maximize the range.


If you really are looking at trying to hit >145 dB then you'll probably have to bypass the off-the-shelf solutions HT solutions anyway...

Quote:
Originally Posted by audiovideoholic  /t/1518672/general-max-spl-point-fr-from-our-more-traditional-offerings-location#post_24378479


Ok, I have been trying to determine where the max and/or continuous spl calculation is located at on some if not most of our preferred manufacturer's products is located.
Sadly, wherever the marketing department decides.
Quote:
Back in my car audio days I was hitting 155+dbs at idle
In a car, maybe, though chances are not really, as what you're reading in a car is as much compression of the air in the small enclosed space as actual SPL. Anyone can take an SPL meter and get an off the scale reading by blowing into the mic. Continuous exposure to an actual SPL level of 155dB would render you deaf in short order.

As for manufacturer max SPL numbers, all are fantasy. They calculate the max SPL by linear extrapolation of the driver thermal limit versus base sensitivity. But SPL increase over base sensitivity for more power applied is not linear. Between thermal and mechanical power compression and the displacement limits of the drivers calculated max SPL can be 6dB higher than actual.
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Don't forget that extra 3dB for converting to peak SPL either Bill.


Another problem is that in many designs the drivers cannot even handle the maximum power used for the calculated SPL over the full intended bandwidth without damage or serious over excursion.
Actually the real answer is that it doesn't matter unless you are setting up a 1000 seat theater and even then it isn't that hard to figure out. The point is that max SPL for mains speakers is basically a moot point with any of these speakers in even the craziest home setting with the craziest user.


Why don't they publish it? Because there is no "it" defined for Max SPL. Max SPL before it fails? How long? Max SPL before it sounds bad? Define "bad". Compression? Distortion benchmarks?


The issue is minimally about the fact that most speakers measure within +/-3db. Sure, that would impact how the speaker is tested, but less than the fact that a speaker will "run out of steam" at different spots.


Now, Ricci does this testing with subwoofers because subwoofers need to output far more SPL and reaching the maximum SPL of a subwoofer, especially at very low frequencies is a realistic issue.


It is easy to estimate the thermal maximums on main speakers though based on what the driver manufacturers publish (if you believe the specs of course). Will the speaker sound good at those levels? Like I mentioned before, how do you want to quantify that and test it?


We've gone over much of this in the other thread but I think you lack an actual understanding of 130db+ at higher frequencies...or you are deaf. Bill is right, you weren't actually producing 155db in your car. You also probably weren't doing more than 110db at higher frequencies unless you were using horns and you certainly weren't in the car without ear protection.


What are the details of this 145db HT sub setup you have right now? Over what bandwidth? What have you used to measure that SPL level or are you just simming that you have 145db max SPL? What mains are you using now?
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Quote:
Originally Posted by mobeer4don  /t/1518672/general-max-spl-point-fr-from-our-more-traditional-offerings-location#post_24378718


Well....you could make a reasonable assumption that the -3 dB points are going to be at the ends of the FR curve since the woofer and tweeter eventually give up. The +3 dB point may be much harder to find since a 3 dB peak might might sound quite nasty depending on where you find it...like horn honk. So the better designs probably focus on getting rid of the annoying peaks which is why you might see +1dB/-3dB used as a specification. So the peak SPL should be over a broad range and not just one octave...and active equalization would be used to maximize the range.


If you really are looking at trying to hit >145 dB then you'll probably have to bypass the off-the-shelf solutions HT solutions anyway...

Thanks LTD and thank you.


I was mainly curious about if the numbers where coming from the bass drivers down say under 100hz as the difference between a speaker that will play down to say 60hz and that +3db number did indeed come near that end of the FR for the bass driver it wouldn't be better/louder than another speaker that is rated 3db louder if the sub system was covering it up.


I was just curious like stated above and am sure any 13(x) db speaker will do just fine if there is headroom once pushed to 12(x)db at the seats.


I'm not trying to have 140+db from say 200hz and up but rather have loudspeakers that keep up with 145+db from the subs. I boost the low end by about 15-20db (depends on content) like most so would need "guessing" aprox 125ish db at seats in order to still sound right/keep up with subs.


Does that make sense?
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Quote:
Originally Posted by Bill Fitzmaurice  /t/1518672/general-max-spl-point-fr-from-our-more-traditional-offerings-location#post_24378893


Sadly, wherever the marketing department decides.


In a car, maybe, though chances are not really, as what you're reading in a car is as much compression of the air in the small enclosed space as actual SPL. Anyone can take an SPL meter and get an off the scale reading by blowing into the mic. Continuous exposure to an actual SPL level of 155dB would render you deaf in short order.

As for manufacturer max SPL numbers, all are fantasy. They calculate the max SPL by linear extrapolation of the driver thermal limit versus base sensitivity. But SPL increase over base sensitivity for more power applied is not linear. Between thermal and mechanical power compression and the displacement limits of the drivers calculated max SPL can be 6dB higher than actual.

No need to accuse for false accusations.


If want to call someone a liar then just say it.


Term lab isn't affected by wind like other mics is my understanding. I could be wrong but that would imply that all these people that are putting hundreds of thousands of dollars into an "SPL" vehicle aren't truly setting "SPL" records.
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Quote:
Originally Posted by coctostan  /t/1518672/general-max-spl-point-fr-from-our-more-traditional-offerings-location#post_24379296


Actually the real answer is that it doesn't matter unless you are setting up a 1000 seat theater and even then it isn't that hard to figure out. The point is that max SPL for mains speakers is basically a moot point with any of these speakers in even the craziest home setting with the craziest user.


Why don't they publish it? Because there is no "it" defined for Max SPL. Max SPL before it fails? How long? Max SPL before it sounds bad? Define "bad". Compression? Distortion benchmarks?


The issue is minimally about the fact that most speakers measure within +/-3db. Sure, that would impact how the speaker is tested, but less than the fact that a speaker will "run out of steam" at different spots.


Now, Ricci does this testing with subwoofers because subwoofers need to output far more SPL and reaching the maximum SPL of a subwoofer, especially at very low frequencies is a realistic issue.


It is easy to estimate the thermal maximums on main speakers though based on what the driver manufacturers publish (if you believe the specs of course). Will the speaker sound good at those levels? Like I mentioned before, how do you want to quantify that and test it?


We've gone over much of this in the other thread but I think you lack an actual understanding of 130db+ at higher frequencies...or you are deaf. Bill is right, you weren't actually producing 155db in your car. You also probably weren't doing more than 110db at higher frequencies unless you were using horns and you certainly weren't in the car without ear protection.


What are the details of this 145db HT sub setup you have right now? Over what bandwidth? What have you used to measure that SPL level or are you just simming that you have 145db max SPL? What mains are you using now?


I'm not arguing about spl numbers taken by a term lab meter at sanctioned events. If all the spl contests are just conducted to give owners a sense of false hope then glad I got out of pouring all my money into it. I do know I never quoted any number metered by mids/highs. I plainly said they were extremely loud.


I have measured my room with omnimic and told you that in the last thread. I also told you I didn't think the measurement was accurate with the levels measured. It deffinately sims over 140db and there is room gain. 10 ftw/mal 21s with fp10k clones and qsc amps. Jtr 888s.


Here is screen shot with headroom still left in all of system. Just a hip hop track at LP


] [/URL]
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I guess I'm not really adding anything, but there's not really an answer unless you precisely define what signal you want SPL for, as different spectral content will change what combination of overexcursion/thermal capacity/distortion limits are exceeded.
AVH, not sure if this has been mentioned yet, but think about the equal loudness contour when putting 145db in perspective. We are so much less sensitive to bass that 145db flat would sound WAYYY bright...


Back in your car audio days I'd put money done that you weren't coming anywhere close to 150db from your components in your kick panels




I bet if you ran a moderate house curve down to 5Hz or so, that the SH-50's or the "neos" would hang with your lowend without a problem.


Now if you are looking to find your physical limit, I'd have to say that you are pissing in the wind my friend. I thought I would be able to get close with my setup, but I don't even think doubling up my subs in my space would get me to "that" level...


Just sayin'...

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I'm not sure how those measurements were taken, but it goes to my point that you aren't listening to frequencies above 100hz at 140db (assuming those SPL levels are accurate). Whether by the design of your system's EQ or simply that the content has extremely recessed highs relative to lows.


Now find a movie where there is confirmed content from 10hz to 20khz where the highs are no more recessed than -10db from the lows. EQ your system perfectly flat. Then turn it up until you either see 140db peaks or you can no longer stand it without ear protection. Your JTR 888's should get you to 129db with full rated power.


There are basically 3 reasons why this all a moot point:


1. Your content is already bass heavy so you don't need as much 100hz+ capability

2. You will EQ it even more bass heavy

3. You cannot withstand SPL at high frequencies like you can at low frequencies


Once you account for those three things, you likely need 15-30db less capacity above 100hz than you need below it when listening to the type of bass heavy content that you would with 140db bass peaks. That would put you around 125db needed capacity for the mains which is frankly generous. Nobody would enjoy higher frequencies at those levels.


Post a full range sweep measurement of your system. If you aren't running your subwoofers extremely hot I'll be shocked.


If you post a sweep and you are flat across the whole bandwidth AND you have some content you enjoy that has peaks above 100hz that equal to the peaks below 100hz and you like this content at 140db THEN maybe you need some mains capable of more SPL than JTR T8's. In fact, I think Jericho's are your only choice.
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Quote:
Originally Posted by popalock  /t/1518672/general-max-spl-point-fr-from-our-more-traditional-offerings-location#post_24381594


AVH, not sure if this has been mentioned yet, but think about the equal loudness contour when putting 145db in perspective. We are so much less sensitive to bass that 145db flat would sound WAYYY bright...


Back in your car audio days I'd put money done that you weren't coming anywhere close to 150db from your components in your kick panels




I bet if you ran a moderate house curve down to 5Hz or so, that the SH-50's or the "neos" would hang with your lowend without a problem.


Now if you are looking to find your physical limit, I'd have to say that you are pissing in the wind my friend. I thought I would be able to get close with my setup, but I don't even think doubling up my subs in my space would get me to "that" level...


Just sayin'...


No, nowhere near that from mids/highs. I've never implied that. Thats why I said I've never experienced full range at levels above 12(x)ish but would like FR to be equal to "minus my bass boost" of anywhere between 10-20db at my LP. If subs play at let's just say 140db even then if listening to hip hop I'd like the LCR to output right around 120db at my seats (14-15') away from baffle. If listening to rock then the boost/curve would be less so would need about 5db more so 125db at LP.


Does that make sense? Movies are always around reference with 10-15db curve so my current LCR keep up fine.

Quote:
Originally Posted by LTD02  /t/1518672/general-max-spl-point-fr-from-our-more-traditional-offerings-location#post_24378531


wow...


your observation is astute. most manufacturers don't provide that data. what you want, of course, is a simple request: frequency response every 5db until the speakers crap out. this way you could see where and how that happens.


even better would be response and distortion every 5db until the speakers crap out.


BUT, what company in their right mind would provide such information? answer: none.


so what to do?


short of actual measurements, the best you can do is probably model it up, make some assumptions, and...guess.

As others have stated, there is no simple number. It's akin to asking for a single number to represent how loud a sealed subwoofer can play... (qualifications intentionally not included)


Different marketeers use all sorts of different numbers. Those that aren't just using pie-in-the-sky calculations often use pink noise measurements, sometimes band limited, sometimes not. While the 5dB increasing curves are very interesting and telling of certain behavior, it is important to understand that they might also grossly underestimate the useful loudness of a wide bandwidth loudspeaker. A swept sine wave delivers full power at every frequency individually. With pink noise the power and excursion requirements at each frequency can be 1/6th to 1/20th that of a sine wave of the same total power. Particularly in cases where significant compression is seen in the increasing level curves before maximum amplifier power is reached, useful music and pink noise playback will be a good deal higher than what those curves indicate.


Active designs also are at a disadvantage when only looking at swept sine measurements. Consider a theoretical 2 way speaker powered by a 1kW amp showing a maximum output with a swept sine wave that is amplifier limited. If you had the same speaker which was bi-amplified using 2 1kW amplifiers, the swept sine wave measurements would max out at the same maximum curves, but the Bi-amplified box would likely produce 3dB more with pink noise or music.
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" A swept sine wave delivers full power at every frequency individually. With pink noise the power and excursion requirements at each frequency can be 1/6th to 1/20th that of a sine wave of the same total power."


peaks tend to look a lot more like sine waves than pink noise. just say'n...

Quote:
Originally Posted by popalock  /t/1518672/general-max-spl-point-fr-from-our-more-traditional-offerings-location/0_50#post_24381594


AVH, not sure if this has been mentioned yet, but think about the equal loudness contour when putting 145db in perspective. We are so much less sensitive to bass that 145db flat would sound WAYYY bright...

Depending on which of these sets of curves you go by, we would perceive the bass as becoming relatively louder or keeping up with the rest of the spectrum

https://www.google.com/search?q=equal+loudness+curves&client=firefox-a&hs=5Te&rls=org.mozilla:en-US:eek:fficial&tbm=isch&tbo=u&source=univ&sa=X&ei=CVYFU9WqK9TyyAG7ooHwCQ&ved=0CDMQsAQ&biw=1331&bih=616&dpr=1.25

Quote:
Originally Posted by LTD02  /t/1518672/general-max-spl-point-fr-from-our-more-traditional-offerings-location#post_24381837


" A swept sine wave delivers full power at every frequency individually. With pink noise the power and excursion requirements at each frequency can be 1/6th to 1/20th that of a sine wave of the same total power."


peaks tend to look a lot more like sine waves than pink noise. just say'n...

That depends greatly on what is making that peak noise. That might be the case with some examples in the subwoofer range (certainly not all), but that doesn't follow what I've observed in full range situations. The content and time average which dictates perceived loudness tends to lean more toward shaped pink noise than just sine waves. All music and movie soundtracks we listen to fall somewhere on the spectrum between a sine wave and white noise but never quite reaching those extremes. As such it only makes sense that examining/considering behavior of both extremes will give good insight as to the behavior with content falling in between.

Quote:
Originally Posted by audiovideoholic  /t/1518672/general-max-spl-point-fr-from-our-more-traditional-offerings-location#post_24378479


I just want to do better than keep up with 145+db bass in my ht!!!

A total overhaul is in store!

haha, Like a boss!



I'd hazard a guess (without measuring or anything) that the max spl is between 100hz to 4khz in 99% of the cases... and for subwoofers about 50hz. All depending on the tuning/XO/overall-design of course.


That said, things are starting to look flatter above 90db.









So far I've logged somewhere around 17,000 to 30,000 hours at (or well above) 90db. (and I'm only 30 and my system keeps getting beefier each year)

I guess I'm done-for...
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Quote:
Originally Posted by audiovideoholic  /t/1518672/general-max-spl-point-fr-from-our-more-traditional-offerings-location#post_24381126


Term lab isn't affected by wind like other mics is my understanding.

TermLab is affected by wind, but only in Nasa-mode, in the comp-mode (i.e >10hz) I can't remember... I'd have to double check.


I could believe that 10 Mal's powered by two clones and a QSC would be definitely 120 to 150 depending on distance and room-modes, and a few other things.


Will you be buying a TermLab?


Here is 1 sealed LMS-18 with 1ch of a 10kQ @ 6inches on the TL. The Mal's are probably very similar.




So 2 LMS = 129db, 4 LMS = 135db, 8 LMS = 141db, 10 LMS = 142db

@ 6 inches



hmmm...
117db never looked so serious in TermLab-land, at a distance, in free-space
(Now you have me curious, I'll have to try some music with it at a distance, stand-by
)


Note: The noisefloor of a TL is roughly 105db, they recommend 115db+ measurements ONLY.
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Ok here we go. Blowing into it gave me this, clearly not a sinewave and in the infrasonic range.
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