Thanks for replying. Notice that as per the above link, when Troy Crowe measured and listened to the 1480Be he did so with this horn. https://josephcrowe.com/products/es-600-bi-radial-horn-3d-cad-file
I have a brand new pair of those same Radians which I want to ship to him to review against my pair of vintage Yamaha JA6681B. Troy might test both the Yamahas and Radians in the ES600 horn, though more likely in this one. https://josephcrowe.com/products/cu...del-make-any-size?_pos=4&_sid=d357e67d0&_ss=r and using this adapter. https://josephcrowe.com/blogs/news/...2-for-yuichi-a290?_pos=2&_sid=d357e67d0&_ss=r
At the moment, I'm trying to find a secure and more affordable way to get the Radians shipped via UPS from NY to Canada. That duty tax can be a killer.
Though the tests have yet to be done, of course, please share any experiences, thoughts and advise you may have about these drivers, Ditto the B & C DCM50, though a very different driver.
I did recommend the DCM50 as a candidate for testing in 600-800mm horn to a friend, but I never dragged my *** over and listened to them myself. He was very pleased with them and described them as warm an generous down towards the cutoff of the horn. But maybe not a great candidate for high crossover points.
Price aside, the smoother high frequency response, higher sensitivity due to lighter weight, and lack of ringing of the beryllium diaphragm on the same driver and horn are quite visible in the video linked in #1830:
Of interest, there are many users that prefer the "sparkle" the additional 4 (or more) milliseconds of high frequency ringing the titanium or aluminum diaphragms have over the beryllium diaphragms.
Art
This is exactly what Troy Crowe and Lynn Olson agreed on for Lynn's "Beyond the Ariel" speakers; post # 15,334. https://www.diyaudio.com/community/threads/beyond-the-ariel.100392/page-767
Lynn's been away from that thread for weeks but for someone who's forever heaped praises on neutral sounding berylliums why would he now choose a warm sounding paper/polymide driver? I could see if much of Lynn's source material were worn out vinyl, analog tape and/or CD recordings hit with too much compression and/or congested sounding orchestral passages, due to tape saturation, poor miking/baffling techniques. Then he might well fear exactly what I do-the Radians, however carefully EQed, will accentuate the worst sounding aspects of my CDs. That's why I want to ship them to Troy; so he can tweak them and hear them will ~ 35 of my uncompressed WAV files of CD track rips via my Google drive.
Don't know ... there is only one company in the world which can do it as far as I know that's probably part of the price problem ...
Did you compared the sound of both T34? I only had the T34A here in a prototype and compared in a well dampened room to T25B. And prefered T25B.
But T34A is crazy off axis, I had the impression there is even more top end off axis as with T25B.
I didn't had the chance to give a listen to the T34B but to be honest also being curious if there is a lot of sound difference beside the off axis behaviour - resonance frequencies are pretty close.
That is correct.
the T25b has the "same diaphragm shape as the T34B, that is why.
easily seen in the measurements.
Attachments
Hello
Can you point out where you have seen break up modes in 4" Be compression driver measurements?
Rob 🙂
It is hard to determine such things on frequency response curves as everything is filtered through a phase plug. I will however recommend this article:
https://audioxpress.com/article/Voice-Coil-Spotlight-The-Beryllium-Advantage
If we look at this figure:
We can clearly see that beryllium is a significant improvement over aluminium or titanium. However, we can also see that there are several wavelengths within the radius of the dome at 4 inch/26,9kHz. The 1 inch dome has its first resonance at 26,16kHz. Moving up to a 4 inch with the same profile, this should give us the same initial resonance at around 6,5kHz. What we typically consider to be the break up point is close to 1 octave above this point. The first resonance is typically not as pronounced on domes as it is on cone drivers, so it is really not to be regarded as a problem.
But there are two huge factors to add to this. One is that the above figure is very shape dependent. To my understanding, it is based on a simple dome with the materials Youngs modulus and mass as the main mechanical properties. In practica cases we can see 1 inch aluminium domes breaking up at 15kHz, but also at 30kHz. This is very shape dependent. There are also other properties in the material that comes into play when we use a taller dome profile. It is a bit like comparing a flat stone bridge to a flat steel bridge. It does not tell us all about the differences between arced stone and steel bridges.
Also, my comment was that the typical sonic signature of a beryllium 4 inch dome would not be the same as a 1 inch beryllium dome should be valid. It is more reasonable to say that the sonic signature of a beryllium 4 inch dome is close to the sonic signature of a 2 inch aluminium dome.
https://audioxpress.com/article/Voice-Coil-Spotlight-The-Beryllium-Advantage
If we look at this figure:
We can clearly see that beryllium is a significant improvement over aluminium or titanium. However, we can also see that there are several wavelengths within the radius of the dome at 4 inch/26,9kHz. The 1 inch dome has its first resonance at 26,16kHz. Moving up to a 4 inch with the same profile, this should give us the same initial resonance at around 6,5kHz. What we typically consider to be the break up point is close to 1 octave above this point. The first resonance is typically not as pronounced on domes as it is on cone drivers, so it is really not to be regarded as a problem.
But there are two huge factors to add to this. One is that the above figure is very shape dependent. To my understanding, it is based on a simple dome with the materials Youngs modulus and mass as the main mechanical properties. In practica cases we can see 1 inch aluminium domes breaking up at 15kHz, but also at 30kHz. This is very shape dependent. There are also other properties in the material that comes into play when we use a taller dome profile. It is a bit like comparing a flat stone bridge to a flat steel bridge. It does not tell us all about the differences between arced stone and steel bridges.
Also, my comment was that the typical sonic signature of a beryllium 4 inch dome would not be the same as a 1 inch beryllium dome should be valid. It is more reasonable to say that the sonic signature of a beryllium 4 inch dome is close to the sonic signature of a 2 inch aluminium dome.
Unfortunately I have not had the oportunity to do that. But I see that they are both measured by Audio Compass. It is quite fascinating to see how close they are to each other.
I often argue that top end dispersion is one of the audible advantages of great metal domes. It seems like you have come to the same conclusion.
My description, and probably @superlian (who I recommended it to) did also focus on this, is that the interaction between the driver and the horns low end seemed to work unusually well for larger midrange horns. I do not think he used it very high up in frequency, so the sonic character of the material itself should not contribute. I do not know Mr @Lynn Olson 's project, so I have no clue how they are using it.
For those on a budget and only looking for a 1" driver to mate with a midbass or in an MEH, i submit this
https://faitalpro.com/en/products/HF_Drivers/product_details/index.php?id=502010193
This is the 16ohm version....the response is much flatter than the 8ohm go figure?
https://faitalpro.com/en/products/HF_Drivers/product_details/index.php?id=502010193
This is the 16ohm version....the response is much flatter than the 8ohm go figure?
Thanks
Might be on an FR curve although typically the peaks are visible you have irregularities in the impedance curve and clearly visible in a waterfall plot
The domes in the table are all 4" How are we moving up from a 1" dome? 26.19k is the first on a 4" not a 1"? Are you considering the 1st bend mode as a resonance?
I don't see how you could off the cuff say that this 4" Be should sound like a 2" Al.
Based on what??? Really should be looking waterfalls to see what is actually happening.
Rob 🙂
Yes as @Snickers-is mentioned i prefered B&C DCM50 (450-2800 Hz) instead of JBL2446 with Truextent beryllium (600-3000 Hz) in the Tractrix 200 horn.
DCM50 have a organic smooth airy and very detailed warm sound. In the classical ca 300-3000 Hz «thelephone» range it cant be much better 🙂
DCM50 have a organic smooth airy and very detailed warm sound. In the classical ca 300-3000 Hz «thelephone» range it cant be much better 🙂
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But if i compare all factors i honestly think i have better sound today with my current system on the picture here and it is better sounding that almost every other systems i have heard. I am very «afraid» of selling the JBL2451 Truextent beryllium drivers i have. Maybee i never get as good sound again?
I have an ambivalent "relation" to metal domes. I really dislike the older metal domes with resonance frequencies in the 18-23kHz area. And I really like the Beryllium domes from Bliesma or Scanspeak with their very high resonance Frequencies (35/50kHz). I still prefer T25B over T25A in direct comparison ... not exactly sure why cause T25A resonance is already relatively high. But T25A is way better as old metal domes for me.
So I run with the thesis to use hard dome tweeters with as high resonance as possible but not exactly sure why and where the needed limit is.
(I can imagine why - to get perfect piston movement without first breakups starting. The laser scan in your link shows unstabilities in the domes before they break up in a mode, maybe that's a point. But that's not proven so far.)
Back to compression drivers - I prefer ring radiator drivers so far, BMS Coax or B&C DE360. They don't have nasty breakups and stay on the nice sounding side - this can be helpful in PA situations. But at high levels they get a little to "nice" compared to the truth.
I should have put my glasses on there... But how can they claim that the different modes are at the same frequency?
I don't know??? 1" vs 4" you would expect the 1" to be higher and I didn't see any references to 1" unless I missed it somewhere? That data is from the Materion large format compression driver materials comparison AFAIK it was all based on 4" domes. And they used a JBL core to test.
Rob 🙂
TD12M apollo
They are here today with TAD2001 in the small Tractrix 1000. Audiolense take care of the crossover and it sounds better here than in my room & old system. The new owner altså tells that Purifi amplifiers lifted the sound quality even a little more.
https://www.hifisentralen.no/forumet/threads/bjarnetvs-hi-fi.55582/page-36#post-3724642
They are here today with TAD2001 in the small Tractrix 1000. Audiolense take care of the crossover and it sounds better here than in my room & old system. The new owner altså tells that Purifi amplifiers lifted the sound quality even a little more.
https://www.hifisentralen.no/forumet/threads/bjarnetvs-hi-fi.55582/page-36#post-3724642
Are you sure those are not simulations? Maybe the diameter has been considered secondary, so they have tried to match the size of the dome so that every mode ends up on the same frequency? I have no idea to be honest.