So why settle with 1" compression drivers? Why would dome tweeter (with a waveguide, of course) not be adequate for home use? Why would differences in thermal/intermodulation/harmonic distortions be audible between a 1" tweeter and a 1.75" compression driver, and not between a 1.75" compression driver and a 3 or 4" one?
So there *is* an audible difference after all...
Are you looking for euphonic reproduction with your loudspeakers??
So no change was made to the waveguides themselves?
The B&C has an exit wall angle of 6.5° (I think this data comes from you), whereas the TAD appear to be around 3° (calculated from a cutaway).
A 1" compression driver on a waveguide has at least 20 dB more headroom and efficiency than a standard 1" dome tweeter. That is not an insignificant difference. Going to larger format drivers gains maybe 6 dB more but problems with the upper end. The 1" compression driver is the sweet spot for home use.
And there certainly is a level of aberration below which one cannot detect differences. Finding this level is very important. I always try and do that.
I have never said that all distortion is not audible - that would be absurd. But on the other hand to say that any measurable distortion is audible is equally absurd. Without some way to scale the subjective audibility of measurements one is simply guessing.
Klippel does have their little online threshold test. Maybe they are planning on publishing data using the same test in a controlled environment someday? You can look at the web stats on the page below if you select the test options first and then click "Statistics" in the lower-right. It would appear that some people have been cheating...
Listening Test - Instructions
Listening Test - Instructions
Oh Sure!
I suppose all those that can hear compression driver distortion and address it in their articles are wrong.
Can we hear compression driver distortion? This is the issue.
Klippel’s article does not have your name on it; so of course, it is not relevant (for you only).
Care to denigrate this thread as well?
http://www.diyaudio.com/forums/multi-way/212240-high-frequency-compression-driver-evaluation.html
WHG
I suppose all those that can hear compression driver distortion and address it in their articles are wrong.
Can we hear compression driver distortion? This is the issue.
Klippel’s article does not have your name on it; so of course, it is not relevant (for you only).
Care to denigrate this thread as well?
http://www.diyaudio.com/forums/multi-way/212240-high-frequency-compression-driver-evaluation.html
WHG
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Incredible
This what you did say and it is equally absurd:
"Having used and measured a lot of them my conclusion is that they are all about the same, basically they are a commodity."
Where is the data to support this assertion?
A study covering just three drivers, I suppose.
WHG
This what you did say and it is equally absurd:
"Having used and measured a lot of them my conclusion is that they are all about the same, basically they are a commodity."
Where is the data to support this assertion?
A study covering just three drivers, I suppose.
WHG
B&C has 0.5" (~13mm) and 0.75" (~19mm) throat drivers.
Actually, for most of us there's a relevant and material missing term there: can we hear *** at levels relevant to home audio.
I like your "Serious Audio Blog" link. I had never actually seen that sight.
The level issue is an important one. I once had quite a discussion with Mr. Linkwitz about his claim that 88 dB was the loudest level that anyone would want to listen at - it was his "target" on which all of his calculation were based. In my experience this could be off by as much as 20 dB. This kind of "detail" makes a lot of difference.
The level issue is an important one. I once had quite a discussion with Mr. Linkwitz about his claim that 88 dB was the loudest level that anyone would want to listen at - it was his "target" on which all of his calculation were based. In my experience this could be off by as much as 20 dB. This kind of "detail" makes a lot of difference.
88dB for the average level at the listener location is quite loud.
That would probably require >>100dB @ 1m from the speaker.
That would probably require >>100dB @ 1m from the speaker.
Well you actually can, B&C are producing smaller drivers, guess they are being put into more complex line array systems such as EAW: Eastern Acoustic Works | Anya Sound System - EAW: Eastern Acoustic Works
DE5 B&C Speakers
DE7 B&C Speakers
These do not handle much power but for home use I assume they can give you plenty of SPL. OTOH you cannot cross them over as low as the 1 inch drivers
I am wondering whether Earl has done any experiments with these.
thanks for the B&C references and links.
Looks like the DE5 needs an even smaller driver than the 25mm used in it and the DE7.
The HF is very similar.
4W per channel & 109dB/W @ 1m gets to 110dB at a 2.4m listening distance.
With 10W and 20W specified as the continuous and transient limits they go loud enough for domestic use. Even big rooms with a listening distance of 6m, still hits 110dB.
Looks like the DE5 needs an even smaller driver than the 25mm used in it and the DE7.
The HF is very similar.
4W per channel & 109dB/W @ 1m gets to 110dB at a 2.4m listening distance.
With 10W and 20W specified as the continuous and transient limits they go loud enough for domestic use. Even big rooms with a listening distance of 6m, still hits 110dB.
I think it would be useful not to spin far reaching statements for the purposes of suiting the commercial interests of those directly involved.
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88dB sensitivity is suitable for people living in small apartments. They can't listen at theater levels with respecting their neighbors. And 88dB does not require particularly large boxes for good bass extension. What I observed so far, key for good dynamics in low sensitivity system is splitting signal in as many ways as possible. And that is what SL has done with his four way system.
How does the equality of compression drivers sound quality suite anyone's commercial interest? I would think that ones commercial interest would be better served by claiming that the drivers that they use have "the best" sound quality, not "on par" with everyone else.
Just like in politics, sometimes what gets said is simply wrong just because of who said it. What is said matters little.
Earl,
While I understand your position that compression drivers are interchangeable that would be based on the premise that most problems can be corrected easily with simple eq and level matching. My experience with some compression drivers and I will leave out the name as they are a well known company is that sometimes there are real problems with these drivers. The drivers I am referring to have a real mechanical resonant problem and this is not easily overcome, it is the nature of the design and a flaw in the design. Yes you could notch filter out the basic problem area but that is a band-aid fix and the driver is still inferior for this reason in my eyes. So I have a problem with lumping all compression drivers together. I also think there is a sonic signature to the different diaphragm materials, given the same size voicecoil and all else being the same there will be a difference in sound between an aluminum and polymer diaphragm, they will not sound identical and it is more than just simply eq that would make them the same. The decay rates are not the same, the Young's modulus of the differing materials are very different and the impulse responses will not be equivalent. All compression drivers may work on the same basic principals but the end results don't necessarily match in sound quality.
While I understand your position that compression drivers are interchangeable that would be based on the premise that most problems can be corrected easily with simple eq and level matching. My experience with some compression drivers and I will leave out the name as they are a well known company is that sometimes there are real problems with these drivers. The drivers I am referring to have a real mechanical resonant problem and this is not easily overcome, it is the nature of the design and a flaw in the design. Yes you could notch filter out the basic problem area but that is a band-aid fix and the driver is still inferior for this reason in my eyes. So I have a problem with lumping all compression drivers together. I also think there is a sonic signature to the different diaphragm materials, given the same size voicecoil and all else being the same there will be a difference in sound between an aluminum and polymer diaphragm, they will not sound identical and it is more than just simply eq that would make them the same. The decay rates are not the same, the Young's modulus of the differing materials are very different and the impulse responses will not be equivalent. All compression drivers may work on the same basic principals but the end results don't necessarily match in sound quality.
Hearing
The peak level will depend on what it is that you are listening to and how loud you like to listen to it. Of course the lower, the average level, the less the driver will be challenged and the less your ears will be able to discriminate departures from reality as a low level setting already constitutes such a departure.
At average levels below that of the original performance, the audible frequency range of it contracts. [1]
Typically the constraints on level setting have more to do with whether the listener is an apartment dweller or not. Here a big system is either a lease breaker or a waste of money.
Regards,
WHG
Reference [1]
The peak level will depend on what it is that you are listening to and how loud you like to listen to it. Of course the lower, the average level, the less the driver will be challenged and the less your ears will be able to discriminate departures from reality as a low level setting already constitutes such a departure.
At average levels below that of the original performance, the audible frequency range of it contracts. [1]
Typically the constraints on level setting have more to do with whether the listener is an apartment dweller or not. Here a big system is either a lease breaker or a waste of money.
Regards,
WHG
Reference [1]
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Kindhornman - don't take my claims too far, they don't go as far as you are saying. I never said that all compression drivers are the same. (I said that they were a commodity and that is not the same thing.) There are some that are junk. But when you get past the junk I have found that they all work the same in an optimized design and that the differences, while measureable have not been shown to be audible.
It's this persistent comparison of small and IMO meaningless measurable differences between compression drivers that I just find to be a waste of time. I have done the tests, others have not. If you believe your ears - as so many here seem to - then fine. I do not, and have never, given non-blinded individual perceptions any credence and that is all the contrary evidence that has ever been shown here.
So maybe I have not changed anyone else's mind, but clearly nothing has been shown here that changes mine. That's fine with me, I am not on a pilgrimage to expound my religion. I offer up what I have done and what I believe to be true. Take it or leave it.