Gurus?
Well we are talking about fundamental physics here and people who spend an awful lot of time and effort in actually creating books written from objective scientific research and experiments.
Mostly from articles from the AES and such.
Not about some "gurus".
If those names don't ring a bell, I don't even understand what we are discussing about.
But hey, if you wanna disrespect people like Einstein and Newton as well, be my guest.
I would recommend reading these books first.
Some can be easily found.
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Joined 2003
There's nothing wrong with healthy debate if it provides some insight into driver decisions. For example, I have little to debate about the Beliesma drivers, or Accuton, or Seas graphene, as I will never purchase these drivers due to cost alone, so any opinions I have is solely based on the objective data available. Like many "high end" items, there is a market for these items as a lot of people have the wealth that the price of the product is mostly irrelevant.
The comparison of TC9/TG9 to 15W/4262 is an interesting one as I have interest in both of these drivers and have used the TG9 in the past. The cone material of the 15M is quite the same as TG9 with a coating applied to the Scan Discovery line of fibreglass drivers. Deciding that one is simply "better" depends on your needs. The larger 15M offers higher sensitivity, higher max SPL, but being a larger driver obvious directivity differences, the response has a shelf at 2kHz and 3rd order distortion is quite a bit higher at the top end of the usable response. This 15M would do well with a better motor IMO, as it is the performance is only "okay", and I haven't needed 92dB sensitivity through the midrange for any of my speakers so I would be happy if they used rubber surround instead of foam if it made for a better frequency response with slightly lower sensitivity.
On the "fast" note, I think that is a audio term that should be avoided, as well as "slow" for that matter, as there are a lot of misconceptions of what it means, and leads to much misunderstanding of what is really going on in the acoustic environment.
Great!
Oh you believe in numbers given in spec sheets?
That's cute 😀
Sorry I don't mean that with any offense or mean way at all, just based on years of experience working in that field.
Keep in mind that just 3dB less, will be already half the power needed.
But I am confused as well, because the one you're showing is like a Volt mid?
Which even has a lower sensitivity of 94dB/W, meaning we need 400W to reach 120dB SPL.
I don't really see that happening without proper cooling.
At 900-1000Hz I wouldn't go for a mid anymore, just for an high freq driver.
In general I don't really see the problem with a compression driver.
The distortion of the good ones are right in the same ballpark of high-end tweeters.
Above 10kHz 2nd order distortion isn't much of a thing anymore anyway (plus 2nd order isn't very harmful to begin with).
For 3rd order that's around 7-8kHz.
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Isn't there some Patreon or the like, where we can all top in a few bucks each month? More than happy to sponsor these things in general.
Or rather see some Klippel measurements even.
Well or do these measurements myself, but currently not possible because of the home situation here. 🙁
B_force and Oneminde; you are both right. you are looking at the same thing at slightly different viewpoints.
Reference-
Linear distortion
Reference-
Linear distortion
Not about disrespect, only that frequency response measurement is a limiting factor if that is the only way you are describing a driver.
Can you tell by looking at a building if it is well insulated against colder climate or not ?.. well ofc not, you have to either look at the type of insulation used, by the thickness of the walls, by measuring the R value and also looking at cold spots via an IR camera.
In other words, one set of data points cannot reveal the true value, just like we have learned not to trust some old school magazines to tell us if a loudspeaker is good or not ... 😀
Without knowing what your sources meant when "they" said you can see the transient performance on the frequency response, I am telling you, you cannot. You can see its flatness, low- and high extension, cone/dome breakup region, possible harmonic issues,
but you can't see if any of its parts are experiencing resonances or ringing. For that you need to extend your data points just like we did for the house. And again, this has nothing to do with respect.
Lets look at something else. Two drivers and both have a sensitivity of 89dB/2.83V/1m, measure relatively flat on-axis but when we look at the suspension compliance, one is 0.23mm/N and the other is 1.8mm/N, if all else is equal, the one with poorer compliance
(higher Cms) will typically ring for longer, it is in other words not as quick to settle as the other driver, therefore, the driver with the lower Cms will have better transient performance since it will settle back at neutral faster than the other.
Can you tell by looking at a building if it is well insulated against colder climate or not ?.. well ofc not, you have to either look at the type of insulation used, by the thickness of the walls, by measuring the R value and also looking at cold spots via an IR camera.
In other words, one set of data points cannot reveal the true value, just like we have learned not to trust some old school magazines to tell us if a loudspeaker is good or not ... 😀
Without knowing what your sources meant when "they" said you can see the transient performance on the frequency response, I am telling you, you cannot. You can see its flatness, low- and high extension, cone/dome breakup region, possible harmonic issues,
but you can't see if any of its parts are experiencing resonances or ringing. For that you need to extend your data points just like we did for the house. And again, this has nothing to do with respect.
Lets look at something else. Two drivers and both have a sensitivity of 89dB/2.83V/1m, measure relatively flat on-axis but when we look at the suspension compliance, one is 0.23mm/N and the other is 1.8mm/N, if all else is equal, the one with poorer compliance
(higher Cms) will typically ring for longer, it is in other words not as quick to settle as the other driver, therefore, the driver with the lower Cms will have better transient performance since it will settle back at neutral faster than the other.
The ATC 3” dome has been around for 45 years and is well proven. And ATC isn’t an audiophile manufacturer who lies about their specs. Although I don’t think integration with a 15” woofer would be the best.
The reason I want to use these isn’t because there’s no other drivers capable of achieving high output. It’s because I believe the sound quality in the midrange will exceed everything on the market. I already have experience with the T34B tweeter and it sounds fantastic. The Bliesma T34B can’t be crossed over at 900-1000 and handle 118-120db. So the mid would need to be used in conjunction with it.
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Do you possibly have a thread I can subscribe to and possibly contribute to such that this thread isn't too cluttered from all of the digression 😉
What horn/WG are you using with these, and what driver under them if you don't mind?
Solution to this problem is quite simple - build a waveguide for M74. Look how for example Genelec does that 1238AC - Genelec.com
Ok I decided to do it now. They deserve their own thread. Feel free to chime in.
https://www.diyaudio.com/forums/mul...eries-3-dome-midrange-lineup.html#post6868790
https://www.diyaudio.com/forums/mul...eries-3-dome-midrange-lineup.html#post6868790
I’m not sure, if I find an application that needs more output than the Bliesma can deliver, I’ll figure it out.
I actually have some of those 6.5” PHL mids that they use. These mids can output 120dB with superb resolution. Unfortunately something funny is going on with PHL. And I think they were bought out by someone recently, but never return any emails.
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I don’t know exactly how I would use them. I haven’t used them before. I would probably use something that’s already available rather making something custom. Such as this:
Eighteen Sound - Professional loudspeakers
Which Audioxpress used in their review:
Test Bench: Radian Audio Engineering 950PB and 760NEOPB Compression Drivers | audioXpress
Just keep in mind that review isn’t of the Beryllium dome. That came out after that review. The Beryllium has more range. A plot of the Be here:
Lyd & Akustikk | Nettbutikk
For woofers I’d use a quad array of the upcoming 8” Purifi woofers.
Which one's specifically? They offer several.
Thanks.
I think my friend has some XR2064s.
I'm familiar with Be phragms as I've had TAD2001/4001 before.
The mids I have are the PHL 1120’s.
https://en.toutlehautparleur.com/media/catalog/product/datasheet/phl/1120_1130.pdf
But they had a higher output version which could be ordered with a phase plug. Which is what Genelec uses.
https://en.toutlehautparleur.com/media/catalog/product/datasheet/phl/1120_1130.pdf
But they had a higher output version which could be ordered with a phase plug. Which is what Genelec uses.
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