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Hi Guys,
I’m really interested in cloning the Sunfire XT CRM-2 for my stereo listening. They have an interesting look and possibly an enjoyable sound, If I make them right.
From the image it appears that the planar tweeter is a Silver Flute YAG-20 (Dayton PT2B-8 ), with two high excursion 4.5” woofers, one on either side of the cabinet in a common sealed enclosure.
After researching the CRM-2 and downloading the owner’s manual these are the specs:
Drive Units
HF - Wave Guide loaded Neodymium Ribbon
LF - Dual 4.5 inch High Back EMF
Freq Responce
95hz - 40kHz
Crossover point
1.5kHz
Max Power
400w
Min Power
25w
Sensitivity
90db @ 2.83V/1m
Max output
115dB
Impedance
8ohm
Dimensions
8.25"H
5.5"W
6"D
9lbs
xt owners manual
I find the cross over point the most interesting. Because from all the reviews and measurements taken of the Silver Flute/Dayton planar tweeter, there is a lot of distortion under the 2.5KHz mark. And, Zaph has said that this particular planar is “probably one of the worst performers I've ever seen” (http://www.zaphaudio.com/nondomes).
Also what’s interesting is the bass management switch on the back of the cabinet. With my limited experience I’d guess this switches the woofer configuration from di-pole to bi-pole.
I’m thinking that instead of using 4.5” units I take them up to 5” models. My preference is the Dayton RS125S 5” woofer. From all reports they have all the makings of a real solid performer and aren’t too hard on the wallet. Using the same planar tweeter would be the way to go, Dayton PT2B-8.
From ploting the RS125S responce curve using WinISD, it looks like two woofers could work in a 0.14cu.ft. enclosure to yeild a similar low frequency responce of 95hz. I don't think the woofer will be the problem in this design, the planar tweeter might have some distortion issues at a 1.5kHz x-over frequency. Parts Express recommend a 2.5khz 3rd order x-over, and Zaph says "None of the true ribbons, when used one at a time, should be used below 2.5kHz. The higher you cross them, the better you will avoid low end distortion" (http://www.zaphaudio.com/nondomes). I think that if the woofer is XO'd too high it might steer the sound too much.
As it says in the title of this thread I'm thinking out loud. But, I do need some guidance. My main concern is getting the tweeter to work with the design and intergrate with the woofers. Having a good x-over (IMO) seems to be the way to achieve a good result with this design. If anyone has some data or ideas how to make this all come together your help would be great.
I’m really interested in cloning the Sunfire XT CRM-2 for my stereo listening. They have an interesting look and possibly an enjoyable sound, If I make them right.
From the image it appears that the planar tweeter is a Silver Flute YAG-20 (Dayton PT2B-8 ), with two high excursion 4.5” woofers, one on either side of the cabinet in a common sealed enclosure.
After researching the CRM-2 and downloading the owner’s manual these are the specs:
Drive Units
HF - Wave Guide loaded Neodymium Ribbon
LF - Dual 4.5 inch High Back EMF
Freq Responce
95hz - 40kHz
Crossover point
1.5kHz
Max Power
400w
Min Power
25w
Sensitivity
90db @ 2.83V/1m
Max output
115dB
Impedance
8ohm
Dimensions
8.25"H
5.5"W
6"D
9lbs
xt owners manual
I find the cross over point the most interesting. Because from all the reviews and measurements taken of the Silver Flute/Dayton planar tweeter, there is a lot of distortion under the 2.5KHz mark. And, Zaph has said that this particular planar is “probably one of the worst performers I've ever seen” (http://www.zaphaudio.com/nondomes).
Also what’s interesting is the bass management switch on the back of the cabinet. With my limited experience I’d guess this switches the woofer configuration from di-pole to bi-pole.
I’m thinking that instead of using 4.5” units I take them up to 5” models. My preference is the Dayton RS125S 5” woofer. From all reports they have all the makings of a real solid performer and aren’t too hard on the wallet. Using the same planar tweeter would be the way to go, Dayton PT2B-8.
From ploting the RS125S responce curve using WinISD, it looks like two woofers could work in a 0.14cu.ft. enclosure to yeild a similar low frequency responce of 95hz. I don't think the woofer will be the problem in this design, the planar tweeter might have some distortion issues at a 1.5kHz x-over frequency. Parts Express recommend a 2.5khz 3rd order x-over, and Zaph says "None of the true ribbons, when used one at a time, should be used below 2.5kHz. The higher you cross them, the better you will avoid low end distortion" (http://www.zaphaudio.com/nondomes). I think that if the woofer is XO'd too high it might steer the sound too much.
As it says in the title of this thread I'm thinking out loud. But, I do need some guidance. My main concern is getting the tweeter to work with the design and intergrate with the woofers. Having a good x-over (IMO) seems to be the way to achieve a good result with this design. If anyone has some data or ideas how to make this all come together your help would be great.
I've never liked full range drivers to much. Needs a tweeter in my opinion but you know what they say about those. I really like this idea though. It's probably not optimal but who cares. I would say the Neo 8's with a pair of 5" midbass's would be sweet. Or even a single 5".
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