Shinobiwan,
thanks for posting those measurements. I am upgrading the speakers in my digital piano and was thinking of using these drivers--wide dispersion and flat power response are really important for this applicaton. Did I understand that the distortion measurements you made were at 90dB at 2 meters? If so, those distortion specs are absolutely outstanding.
Since you've had a lot of experience working with these drivers, care to share some crossover examples?
thanks a lot, John
thanks for posting those measurements. I am upgrading the speakers in my digital piano and was thinking of using these drivers--wide dispersion and flat power response are really important for this applicaton. Did I understand that the distortion measurements you made were at 90dB at 2 meters? If so, those distortion specs are absolutely outstanding.
Since you've had a lot of experience working with these drivers, care to share some crossover examples?
thanks a lot, John
ScanSpeak R2904/7000
Hi Shin;
At the beginning of this thread you mention that you have measurements on the ScanSpeak R2904/7000 ring radiator. Could you please post these? What do you think of this driver? I have recently ordered a pair of the SM75-150S and the R2904/7000-09 (black instead of aluminum coloured) from Solen. They have not yet arrived so I haven't been able to play with them beyond a bit of computer modelling. I'm just leaning to use LinearX's LEAP software instead of the old way (ie. equations and lots of paper in the wastebasket for me). I figure that my wife is only going to let me buy drivers once so I had best go with the best I possibly can and then I can play with the XO's & enclosures over time. Any suggestions you might have would be greatly appreciated.
Thank you,
Vince
Hi Shin;
At the beginning of this thread you mention that you have measurements on the ScanSpeak R2904/7000 ring radiator. Could you please post these? What do you think of this driver? I have recently ordered a pair of the SM75-150S and the R2904/7000-09 (black instead of aluminum coloured) from Solen. They have not yet arrived so I haven't been able to play with them beyond a bit of computer modelling. I'm just leaning to use LinearX's LEAP software instead of the old way (ie. equations and lots of paper in the wastebasket for me). I figure that my wife is only going to let me buy drivers once so I had best go with the best I possibly can and then I can play with the XO's & enclosures over time. Any suggestions you might have would be greatly appreciated.
Thank you,
Vince
hancock said:
No passive examples from me I'm afraid, I went all manner of active routes with the ATC domes.
Just a few tips really that resulted in the best subjective sound for me. The optimum bandwidth for this driver is 500hz to 3.2Khz with steep filters like 24dB/oct order min and preferably 48db/oct+. Reasons for this is very high distortion below 500hz and dome resonance ~4.5Khz. If you extend the operating range and/or use shallow slopes you can get a rather hard sounding midrange because of the distortion and at the upper end, a fatiguing, harsh lower treble due to the resonance.
The ATC doesn't seem especially bothered about parnering drivers on its low pass but the highpass is especially critical. I found ATC's own bass driver to be a great match overall. Look at paper drivers for the best results I think and forget about alu, magnesium and the stiffer cone types. Look for a bass driver with good sensitivity too as I believe these will match the dome mid nicely.
One quick note is to be sure you level out the passband of the driver, its quite uneven at first but a few bands of PEQ give a near ruler flat response through that important and sensitive mid region.
Thanks for the reply. Are you familiar with the front mount wave guides shown at www.solen.ca? They look a lot shallower than the back mount ones I've seen. That would be great for me if true--again I am worried about achieving a flat power response.
regards, John
regards, John
hancock said:
ShinOBIWAN said:
They are in fact only trim plates that allow front mounting of the driver instead of rear mounting it. The driver attaches to the trim plate which is then screwed to the front baffle of your speaker. I took a look at them earlier this year but they are too big in diameter to work for me; they are about 230mm. I hope this helps. I can say that from my experience Chris at Solen is excellent to work with, very helpful, quick responses, etc.
Vince
Re: Re: Cabinet damping
This that I use is from Monacor for the BAF and Visaton for the lambs wool.
TBH I think its all pretty much the same stuff regardless of manufacturer. The wadding from PE looks fine and you've also got places like Zalytron, Madisound, Speaker City and Michael Percy all of whom can supply BAF or its equivalent.
vincentrubble said:
This that I use is from Monacor for the BAF and Visaton for the lambs wool.
TBH I think its all pretty much the same stuff regardless of manufacturer. The wadding from PE looks fine and you've also got places like Zalytron, Madisound, Speaker City and Michael Percy all of whom can supply BAF or its equivalent.
Re: Re: Re: Cabinet damping
I think that our BAF equivalent is called Dacron Hollofil - which is used as pillow stuffing, sleeping bag insulation, etc. What about Blackhole 5? It has a 1" layer of polyurethane foam (which I believe is open cell foam; closed cell foam would not be useful to increase apparent volume) on the outside. What are your thoughts?
Thanks,
Vince
ShinOBIWAN said:
I think that our BAF equivalent is called Dacron Hollofil - which is used as pillow stuffing, sleeping bag insulation, etc. What about Blackhole 5? It has a 1" layer of polyurethane foam (which I believe is open cell foam; closed cell foam would not be useful to increase apparent volume) on the outside. What are your thoughts?
Thanks,
Vince
Re: Re: ATC SM75-150S Dome Mid Measurement Data
I have no doubt the ATC dome is very good when optimally incorporated into a system - I've heard them in systems with Active x-overs.
How-ever for those of us who cannot afford such driver, and do not need high power capacity there seems to be at least one other quite good dome mid :- Morel MDM 55 .
Sensitivity is specified as 90.5 dB , though with Fs of 380 Hz and the magnitude of the impdance peak there - taking Morel's published plot as representative - it will not likely work well down so low in frequency as the ATC dome, but there are bass drivers which work well up beyond the 600 - 900 Hz area where the Morel could be crossed in.
The old Vifa D75MX -31-08 has been replaced by a D75MX-41-08 from the now combined Peerless-Vifa , but no plots published yet, nor much other information.
Any comments from users or measurers of samples of the Morel MDM 55 ?
thylantyr said:
I have no doubt the ATC dome is very good when optimally incorporated into a system - I've heard them in systems with Active x-overs.
How-ever for those of us who cannot afford such driver, and do not need high power capacity there seems to be at least one other quite good dome mid :- Morel MDM 55 .
Sensitivity is specified as 90.5 dB , though with Fs of 380 Hz and the magnitude of the impdance peak there - taking Morel's published plot as representative - it will not likely work well down so low in frequency as the ATC dome, but there are bass drivers which work well up beyond the 600 - 900 Hz area where the Morel could be crossed in.
The old Vifa D75MX -31-08 has been replaced by a D75MX-41-08 from the now combined Peerless-Vifa , but no plots published yet, nor much other information.
Any comments from users or measurers of samples of the Morel MDM 55 ?
How large was the test baffle for the distortion tests? Question being, the width determines when the driver will roll off (obviously) and output will decrease. I'm just wondering if I was to use a large baffle (how about 3', about the wavelength of 400hz), if I'd be able to extend the response lower (lets say 400hz vs 600hz) without incurring the distortion spike displayed in your test results?
Just for the sake of argument, i fail to see a compelling reason based on the objective measurements to choose this ATC over say, a Dayton RS52. In many ways they are actually quite similar. Distortion levels are similar. Breakup on the rs52, being much higher in frequency means the usable passband on the dayton is larger although the hard cutoff for both on the low-end is about 500Hz. I am not sure about how the dayton fares in terms of dispersion, but being a 2 inch dome, it cant be any worse than the ATC. The biggest difference here is the fact the dayton can be bought for nearly 1/10th the price
Thoughts?
zaphs rs52 test: http://www.zaphaudio.com/smalltest/
I think mark K tested the dome as well and produced similar results
Thoughts?
zaphs rs52 test: http://www.zaphaudio.com/smalltest/
I think mark K tested the dome as well and produced similar results
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