tktran303: thanks for nice comparison. Though they are technically very different I see they all have ~3kHz diffraction and very similar power response and DI curves. KEF looks the least worst though. My conclusion/long term experience is that WG - nonWG - coaxial is not what determines sound quality, and we can see it also does not fully determine measured performance.
Yah.
The (hard) dome tweeter on the flat baffle (albeit with a small round over) absolutely has the flattest and smoother response from 5-20Khz; on and off axis.
Dennis Murphy has been saying he prefers non wave-guided tweeters for a long time. Perhaps this is why.
Hmm.
The more I learn, the more I realize how much I don't know.
The (hard) dome tweeter on the flat baffle (albeit with a small round over) absolutely has the flattest and smoother response from 5-20Khz; on and off axis.
Dennis Murphy has been saying he prefers non wave-guided tweeters for a long time. Perhaps this is why.
Hmm.
The more I learn, the more I realize how much I don't know.
Nah, because every baffle is a waveguide, flat baffle represents the special case of a non-optimised waveguide. Optimised waveguide not only makes off-axes responses more consistent, it actually widens the pattern in top octave compared to naked tweeter. See this sim by @mabat, screenshoted here for ease of reference:
https://www.diyaudio.com/community/...-design-the-easy-way-ath4.338806/post-7354055
I hear what you're saying, that the baffle is a waveguide.
The faceplate or lack thereof affects the polar response.
But I'm not looking to get into the semantics that a circle is an oval and a rectangular is a square.
What I'm trying to getting at-- what should be the "correct" polar response over +/- 180 degrees?
How wide, how narrow, and where?
Is it:
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The faceplate or lack thereof affects the polar response.
But I'm not looking to get into the semantics that a circle is an oval and a rectangular is a square.
What I'm trying to getting at-- what should be the "correct" polar response over +/- 180 degrees?
How wide, how narrow, and where?
Is it:
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Whatever is should be, it should be constant - narrow constant, wide constant, and for flat baffle it is not constant nor flat nor smooth. Alexander at Heißmann-Acoustics explained this very concisely:
https://heissmann-acoustics.de/en/kantendiffraktion-sekundaerschallquellen-treiberanordnun/
Sorry, it evening here and my brain is too tired for ASCII schemes. Maybe you can elaborate?
That does not surprise me, given that you do not seem to be bothered by measuring your systems either.
I
Or i don’t want to show them… because they are only important to me. And only in the context they were taken.
dave
Or i don’t want to show them… because they are only important to me. And only in the context they were taken.
dave
'Most' listeners prefer around 70degrees -6db point. Likely constant directivity (or near)
Toole almost states this. Revel chief engineer (name escapes me at the moment) concurs if you look at his designs. To my knowledge, this is as a result of the most comprehensive research out there.
30% of preference is dependant on bass extension.
The -10db bass point is more important than the -3db.
Real instruments have different pattern control depending on what they are, so there is no 'win' exactly.
I also recall there is decent data to indicate the treble 'tilt' preference is also somewhat dependant on the bass extension of the tweeter. My own experience with IEMs also follows this given the recent purchase of the new (shockingly cheap) truthear crinical RED IEM. I simply still cannot believe this IEM only costs $50. No speaker touches it IMO.
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I agree. I have found that directivity is important up to a point. Wild swings in the DI curve (5 dB or more) will usually have a negative impact on the sound quality. But small +/- 2 dB variations in the DI curve don't seem to matter very much.
I am starting to think it does come down to personal preference, and also it is program dependent. I am still in the process of comparing a waveguide system to a non-waveguide system, so my thoughts and opinions are still in flux. But I can say at this point that I do not have a strong preference across all music. On any given recording, yes, I prefer one or the other. But overall, I can't say that one is superior.
j.
@hifijim
Always the voice of reason. I concur with much of what you've said:
See post:
https://www.diyaudio.com/community/...oncentric-coaxial-drivers.399692/post-7401108
BR,
Thanh
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This is irrelevant to reproduction. We are reproducing the recording, not the instruments themselves.
Klang & Ton has measured this coax with quite good results about 2 years ago ... early breakup for the large carbon dome but well damped several peaks above 1000Hz with average distortion .... hard to guess if it will sound good!
https://www.lautsprechershop.de/chassis/morel_en.htm#h_coax
https://www.lautsprechershop.de/pdf/morel/chassis/morel_powerslim6_integra_carbon.pdf
In the same issue they measured also the normal dome version without the cutout and it is much better!
Has anyone actually used the Satori coax?
It is currently available at Madisound:
https://www.madisoundspeakerstore.com/coaxial/satori-mt19cp-8-coaxial-with-papyrus-cone-8-ohm/
It is currently available at Madisound:
https://www.madisoundspeakerstore.com/coaxial/satori-mt19cp-8-coaxial-with-papyrus-cone-8-ohm/