I agree completely. I've not came across any large diaphragm 2" exit compression drivers that can reach much past 15KHz to 16KHz without some heavy handed measures.
This I don't agree with. I can understand that most 1" exit compression drivers don't do a convincing job up to 20KHz, but the BMS 4540ND does and then some. The 4540ND mated to an 850Hz Le Cleac'h crossed at around 1.5KHz goes cleanly past 20KHz. This is the combination you should have a listen to.
The guys over at HT Guide had a thread about the 4540ND on an Eighteen Sound XT1086. Their results are pretty good, but the Le Cleac'h is better. The OP in the below thread noted that he could push the 4540ND as hard as he liked and it never sounded stressed or distorted.
http://www.htguide.com/forum/showthread.php?20386-Xt1086-bms-4540nd
I like ribbons too. They can often be a better solution than a compression driver and horn. I never lock myself into one kind of driver technology. Everything has its place.
That's a shame, you should. You would be convinced. A good waveguide does not sound anything like a "pro" horn. They sound very much like a good tweeter only cleaner and more dynamic. No coloration at all. You can see a typical JBL driver and JBL horn on my website in PolarMap. Compare it to a good waveguide like the NS-15 and you will see how different they are.
I believe that there is and apparently so do the guys at JBL. Thermal modulation will be lower in a high efficiency driver by a factor of as much as 1000.
I did once experiment with a 15" bassmid of who knows what brand
and an Eminence 1" cd in a horn and the result was nothing you are
talking about. The mids were fine, only the highs were rolled off early
around 8-9 kHz. So, I have to conclude that something must have gone
wrong with your projects.
I think the main qualifier in his statement was:
If you stay within the limits of the driver the thermal compression should not be any more given all things equal except driver effeiciency. However, you'd just be listening at an average continuous level of 50dB instead 70dB. Not very practical, but he did say this was a different issue.
Critical.
Driving any harder is effectively overloading.
If a 90dB/W @ 1m driver is supplied with 10W and listened to at 2.5m we get 92dB
If that speaker can take a maximum of 40W continuously, then the maximum at 2.5m is 98dB continuously.
If that speaker can take a short term transient of 70W, then the maximum SPL will be 100.5dB
that is the maximum that the speaker can give without damage.
The actual maximum heard at 2.5m will be a bit lower due to power compression, expect -1dB to -3dB
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Not agree with you, I'm not talking of loud but dynamics ! A low efficienty speakers with all the watt it needs is limited by the coil, the X Max in relation to its small diameter to allow dynamics without distorsion.
After 105 db, I believe most of 85 db driver or widebander with low effcienty has a limitation of dynamic : when you increase the volume it's play louder while you have no more dynamics than before (the limitation is not the one of the reccording or the amp but the one of the driver !). thermal compression, etc: the driver capabilities colapse. You have loud and just distorsion, you ears swear !
This is not artificial in the reccording when the trumpett of Chet Baker play a middle 90 db then have 110 to 120 db dynamics attacks and your driver must be follow if you can play as loud as the reality or even lower but with the same dynamic (difference between the lower & higher note in DB... but the difference on M-F curve). The only one articial thing is if the devices of the sound engineer can not allow to reccord this dynamic but how he can artifiacaly increase the dynamic of an acoustical instrument... i don't see hiow it could be possible😕 to play louder doesn't involve more dynamics. But we know than a pro driver don't distors at 110 to 120 db in the highs if dynamic is involved.
A low efficienty driver with all the watt needed don't climb higher than 100 to 105 db without problems : too much temperature, risk of break, thermal distorsion, etc ! Am I wrong ? why a 12" driver get a better bass than a 6" (bad example for dynamic...) : he moves the same quantity of air but quicly : 2 mm mvt cone instead 20 mm with the 6" : sensation of dynamics is faster then there is less distorsion (bad example because less important in the bass...). But in the middle-highs those distorsion become a problem. I don't think high effcienty is just to play with smal wattage tubes or allow to play louder for our goals butt o increase dynamics without distorsion : so the life in music ! At least that's what I believe to know !
if a 85 db driver of 5" or 3" can play with dynamics with notes at loud as 110 to 120 db for the sortest instants quickly and without distorsions (no a problem anymore with the modern amps) I give up the idea of a higher efficienty... because all those high efficienty cones have also another problems (less maid for micro dynamics e.g.).
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Yes, and :
With a low efficienty driver after increasing the level : yes it plays louder but at the same time the dynamic is compressed (less amplitude between the lower and the higher notes 😀
You increased the loud with the will to have the sensation of more dynamics with Chet Baker or Star way to heaven with Led Zepplin, but you have just a louder flat middle volume !
For having our 115 db peaks we needs our good amp but also the driver can restitute the midle playoing level (let say 85/90 db) while not collapse when peaks are often played : does not the sucess of tubes and CD driver lovers is not just due to volts instead current while less distorsion is involved because more effcienty ?
My understanding of this thread is the 1k hz to 4 khz frequency is hard to avoid because also the relative choice of drivers technology in the global design of the speaker and its load ! trade offs !
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Correct, but only meaningful in the sound production/reinforcement world (or maybe the fraternity basement/playroom), where very high SPL at the speaker (and sometimes in the audience as well) are the order of the day. Unlikely to be an issue (in a well designed speaker) in the home reproduction world, where SPL over 105dB are somewhere between unlikely and idiotic.
But we talk about short peaks (dynamics) : neighbourhood have less problem when a middle level (75 to 80 db)is played with high dynamics peaks (105 db and more) than a higher midle level (85 to 90 db) with less dynamic capability just because we allow to play loud in the (false) hope of dynamic...
At least that's what I believe, there is also your ears than have the habits of loud and need you increase the volume after some minutes ! Another story !
Umpteenth plus one - thermal compression is not thermal modulation. Thermal modulation occurs at all listening levels.
SPL peaks over 105 dB (C) are not that uncommon, and very common in a home theater at typical theater levels.
sorry Earl but I have looked, read your statements and your distinction is still cryptic
you have not succeeded in explaining - you have to be willing to interact, understand objections, restate, illustrate if you are claiming a new insight that you want to share
it is easy to show, measure the averaged Voice Coil R thermal modulation - but I don't see how that indicates any doing so were ignorant of "instantaneous" heat capacity filtered integration of power loss
and mere existence of an effect is still no indication of magnitude - by your own claims low order distortions aren't readily audible - and you have yet to show relative magnitude of this "instantaneous" TC effect
you have not succeeded in explaining - you have to be willing to interact, understand objections, restate, illustrate if you are claiming a new insight that you want to share
it is easy to show, measure the averaged Voice Coil R thermal modulation - but I don't see how that indicates any doing so were ignorant of "instantaneous" heat capacity filtered integration of power loss
and mere existence of an effect is still no indication of magnitude - by your own claims low order distortions aren't readily audible - and you have yet to show relative magnitude of this "instantaneous" TC effect
I think the cinemas I attend reproduce louder than 110dB
I also believe they do it to "impress" the audience rather than to make it sound "realistic".
When we sit and hear the actors speaking, it is way above what we expect from normal people speaking.
I saw a Post recently that stated the method of setting up the sound levels and thought - "that's not the way it appears/sounds in our cinemas".
The next criticism, following on from that alleged bad set up, is that the crescendos are badly distorted. The system is simply incapable of playing that loud cleanly.
I come away NOT impressed.
I also believe they do it to "impress" the audience rather than to make it sound "realistic".
When we sit and hear the actors speaking, it is way above what we expect from normal people speaking.
I saw a Post recently that stated the method of setting up the sound levels and thought - "that's not the way it appears/sounds in our cinemas".
The next criticism, following on from that alleged bad set up, is that the crescendos are badly distorted. The system is simply incapable of playing that loud cleanly.
I come away NOT impressed.
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All sorts of non-linear distortions occur at some (theoretically) measurable level in loudspeaker drivers, but as you so often note we can't/don't hear them.
And I thought we were talking about quality audio reproduction here, not "action movie" soundtracks . . .
no. if the driver is capable of reaching 0dBfs then the range from normal to loud is preserved. It's when the driver is overloaded that you lose some of the range.
I don't understand that part.
Well the bolded is the problem No.1 - You did it once but I did it lots of times with 15" bass drivers of known brands with known TS parameters and using measurement equipment to see what is going on. Other than that i listened, as i mentioned earlier - summa, couple of 15" Tannoys, JBL 4430 and couple od DIY loudspeakers in which guys tried to make xover high but then ended up with xover point at arround 600Hz most of the times so i have larger sample that i base my judgement on. In a few days i'll get Beyma 15LW30 so i'll try that too. Pics of couple speakers that i listened are in my previous posts.
Problem No.2 . I didn't say that sound from two way with 15" woofer xovered at 1KHz will be unlistenable. If that was the case no 15" two way speaker with xover at arround 1000Hz would exist. The real test is side by side with that same 15" bass and 1" Eminence compression driver and with dedicated midrange added, xovered 400Hz or lower - with that same bass and tweeter.
So you see, you haven't done experiment that i'm talking about. You did experiment to see if 15" woofer can make any sound with 1" Eminence driver in a horn and that doesn't have much in common with what i'm saying here.
Most important thing that you overlooked is that i do believe that some of the 15" woofers can work that high but not just any woofer. IMO it should be woofer that has Mms very low and as lower Le as possible. That's why i mentioned that Altec/GPA 416, Eminence Deltalite II 2515 or AE TD15M looks like they could do the job properly - i wrote that earlier in the thread.
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