I would like to build the eidelon-clone version. If no one has the specs I guess I will try and design myself. One question. I believe that's a port in the bottom of the picture. Any quesses as to what the cabinet is tuned to.
An externally hosted image should be here but it was not working when we last tested it.
There is a Hifi News magazine review on the Avolon Eidolon by Martin Colloms February 2003 edition which gives away quite alot of info on driver descriptions and bass tuning, cabinet size as follows:
1. 270mm Eton kevlar and nomex woofer tuned to 19hz in 75L ported cabinet. Has to be Eton 11-581 Hex woofer.
2. Pure ceramic mid (90mm) and treble units from Accuton. Mid must be C79.
3. Crossover range of mid is 300-3500hz. But Lab report says xo range is 275 and 2700hz.
4. 4 ohm speaker load, 85dB efficiency.
5. Cab size
I am also thinking of building this but using a Raven R1 tweeter instead. I have compared the R1 to an accuton C23 and the Raven is much more detailed and interesting.
Practical efficiency of speaker of 86dB is quite low so maybe baffle step correction was used in the crossover.
1. 270mm Eton kevlar and nomex woofer tuned to 19hz in 75L ported cabinet. Has to be Eton 11-581 Hex woofer.
2. Pure ceramic mid (90mm) and treble units from Accuton. Mid must be C79.
3. Crossover range of mid is 300-3500hz. But Lab report says xo range is 275 and 2700hz.
4. 4 ohm speaker load, 85dB efficiency.
5. Cab size
I am also thinking of building this but using a Raven R1 tweeter instead. I have compared the R1 to an accuton C23 and the Raven is much more detailed and interesting.
Practical efficiency of speaker of 86dB is quite low so maybe baffle step correction was used in the crossover.
The plans that I have spec a 40 litre cab tuned to 35hz. That's probably going to be sufficient for my needs. Guido uses the 8-800/37 for the woofer in his cab and I will probably stay with that. Not really knowledgeable enough to deviate too much from the cross over he spec'd out.
Just for fun this week I'm going to go to some cabinet makers and see what they'll charge to make the enclosures. Because of my skill level I think getting the angles right for these is going to be a lot of trial and error.
Just for fun this week I'm going to go to some cabinet makers and see what they'll charge to make the enclosures. Because of my skill level I think getting the angles right for these is going to be a lot of trial and error.
Here's a cropped image (bad) of the .wmf files that guido sent me. The diy version looks doable. You'll see a total of six braces and onepartition for the mid chamber. Again if anyone wants the full file send me an email.
An externally hosted image should be here but it was not working when we last tested it.
If you are thinking Guido's speaker is a more exact copy of the real Eidolm uses the 11-581 11" woofer not a 8-800 8" unit. The response curves and resonance peak behvious of the 11" and 8" are quite different. 11" is one of the best behaved units around with no response peak until 2hkz, whereas the 8" has peaks before this. Check the specs out on the Eton website.
I have the C79 mid and Raven tweeter and tried a basic 2nd & 3rd order crossover with 2800 & 400 crossover using 2 x 8535 7" Scanspeak woofers in 80L cabinet and the results are already very good. With further work it will only get better. The C79 midrange has lots of natural imaging and detail ability which should make up a little for lack of ultimate DIY crossover skills.
I have the C79 mid and Raven tweeter and tried a basic 2nd & 3rd order crossover with 2800 & 400 crossover using 2 x 8535 7" Scanspeak woofers in 80L cabinet and the results are already very good. With further work it will only get better. The C79 midrange has lots of natural imaging and detail ability which should make up a little for lack of ultimate DIY crossover skills.
I think the main redeeming features of the various Avalons are the Thiel/Accuton midrange and tweeters, (just to settle the matter 
). Why is the focus on copying someone else's design? Not that I believe in honesty or anything like that but it's meant to be DIY, not doing commercial lookalikes on-the-cheap.
My speakers consist of Thiel C-94 8ohm, C-23 tweeter 6.1ohm, plus mono subwoofer (Jaycar Response Carbon Fibre 12" 4ohm for all us NZers and Ozzies). The tweeter's very good, and the midrange is very good too (15L sealed box). 2750Hz passive crossover, 3rd order high and low-pass, with L-pad for the tweeter to equalize its sensitivity. (Please remember to add the woofer's effective voice-coil inductance into the crossover equation.) I used Electronic Workbench Multisim demo to model the crossover - highly recommended; can't be done without it (or some similar program). An important thing that I realized: when modelling the frequency-response, measure the voltage across the resistive part of the VC, and don't include the reactive part. Otherwise measurements will be incorrect, and the crossover for the C-94 could appear to be impossible to do at such a high frequency, thanks to the speaker's high inductance.
6th-order lowpass for the subwoofer at 125Hz (active of course), with a slight 1st-order bass boost to compensate for the natural response of the sealed box. I originally made the active crossover 4th-order at about 90Hz (with active high-pass for the midrange), but found that since everything else was so clean, unwanted voice/instrumental sounds were coming through the subwoofer and wrecking the sound. The 6th order filter put an end to that, and it well-and-truly chops off the high frequencies.
If I were to do this all over again, this is what I would do differently:
I'd try the C-12, plus C-79 midrange with the compulsory ferrofluid. The bass would have to be sorted out somehow. Either a smallish woofer (6.5" - 8") + subwoofer as a 3.1-way system. Or, I'd get high-quality biggish (9" - 11") woofers that can preferably handle piston-motion up to 500Hz or more. Magnesium Seas (Excel range) speakers come to mind. Of course, another option would be to use the 50mm midrange (C-49?) together with the C-12, and a high-performance woofer that can go up to 1kHz at least.
The Avalons made me think a bit when I first read about them, but no, I wouldn't make my design like those. I'd keep to certain conservative design principles, but not the ones which say: "make your loudspeaker out of MDF, and put all 3 speakers in the same box".
The C-12 / C-23 tweeters already have enclosures, so they could sit on top in a soft "pin-cushion" enclosure that's absorbant and non-resonant.
From experience, the reflective "back-wave" sound from the midrange in the enclosure is hard to get rid of, even with lots of damping material, and styrofoam cross-sections. Practically nothing gets through the walls, but what seems to happen is that a lot of the sound still gets reflected back through the cone after bouncing around in the box for a while. This would be worse if: 1) the cone was lighter, 2) the speaker had a higher qts 3) the box was smaller 4) the cone was bigger. Therefore really good results should be achieved with the much smaller C-79 if the box-volume is much bigger than it needs to be (like 10L or even more and packed with stuffing!). That way it'll be closer to the theoretical "infinite baffle" where the sound just gets lost inside the box without coming back. Deciding what the box is actually made from is where the experimentation part comes in: something non-resonant, absorbant etc - lots of good ideas around here at diyAudio.
The bass?: A stiff and heavy box, port or no port - this depends on your personal design. At one time I'd have chosen a reflex port, but every time it's a hassle: hissing, theoretical tunings not matching the reality, midrange sounds escaping through the vent....
Crossovers are always the important part, so do some thinking....What then? You end up with 6 boxes, so put the midrange boxes on top of the bass, and the tweeters on top of the midrange. It's a retro look, but hey: if you're paying for Accuton speakers, you'll want them to sound "great", not just "average".
Didn't mean to hijack the thread, but I thought: what's the point of copying Avalon, when it looks like they're just staking their name on the Thiel speakers that they use?
CM
). Why is the focus on copying someone else's design? Not that I believe in honesty or anything like that but it's meant to be DIY, not doing commercial lookalikes on-the-cheap.My speakers consist of Thiel C-94 8ohm, C-23 tweeter 6.1ohm, plus mono subwoofer (Jaycar Response Carbon Fibre 12" 4ohm for all us NZers and Ozzies). The tweeter's very good, and the midrange is very good too (15L sealed box). 2750Hz passive crossover, 3rd order high and low-pass, with L-pad for the tweeter to equalize its sensitivity. (Please remember to add the woofer's effective voice-coil inductance into the crossover equation.) I used Electronic Workbench Multisim demo to model the crossover - highly recommended; can't be done without it (or some similar program). An important thing that I realized: when modelling the frequency-response, measure the voltage across the resistive part of the VC, and don't include the reactive part. Otherwise measurements will be incorrect, and the crossover for the C-94 could appear to be impossible to do at such a high frequency, thanks to the speaker's high inductance.
6th-order lowpass for the subwoofer at 125Hz (active of course), with a slight 1st-order bass boost to compensate for the natural response of the sealed box. I originally made the active crossover 4th-order at about 90Hz (with active high-pass for the midrange), but found that since everything else was so clean, unwanted voice/instrumental sounds were coming through the subwoofer and wrecking the sound. The 6th order filter put an end to that, and it well-and-truly chops off the high frequencies.
If I were to do this all over again, this is what I would do differently:
I'd try the C-12, plus C-79 midrange with the compulsory ferrofluid. The bass would have to be sorted out somehow. Either a smallish woofer (6.5" - 8") + subwoofer as a 3.1-way system. Or, I'd get high-quality biggish (9" - 11") woofers that can preferably handle piston-motion up to 500Hz or more. Magnesium Seas (Excel range) speakers come to mind. Of course, another option would be to use the 50mm midrange (C-49?) together with the C-12, and a high-performance woofer that can go up to 1kHz at least.
The Avalons made me think a bit when I first read about them, but no, I wouldn't make my design like those. I'd keep to certain conservative design principles, but not the ones which say: "make your loudspeaker out of MDF, and put all 3 speakers in the same box".
The C-12 / C-23 tweeters already have enclosures, so they could sit on top in a soft "pin-cushion" enclosure that's absorbant and non-resonant.
From experience, the reflective "back-wave" sound from the midrange in the enclosure is hard to get rid of, even with lots of damping material, and styrofoam cross-sections. Practically nothing gets through the walls, but what seems to happen is that a lot of the sound still gets reflected back through the cone after bouncing around in the box for a while. This would be worse if: 1) the cone was lighter, 2) the speaker had a higher qts 3) the box was smaller 4) the cone was bigger. Therefore really good results should be achieved with the much smaller C-79 if the box-volume is much bigger than it needs to be (like 10L or even more and packed with stuffing!). That way it'll be closer to the theoretical "infinite baffle" where the sound just gets lost inside the box without coming back. Deciding what the box is actually made from is where the experimentation part comes in: something non-resonant, absorbant etc - lots of good ideas around here at diyAudio.
The bass?: A stiff and heavy box, port or no port - this depends on your personal design. At one time I'd have chosen a reflex port, but every time it's a hassle: hissing, theoretical tunings not matching the reality, midrange sounds escaping through the vent....
Crossovers are always the important part, so do some thinking....What then? You end up with 6 boxes, so put the midrange boxes on top of the bass, and the tweeters on top of the midrange
. It's a retro look, but hey: if you're paying for Accuton speakers, you'll want them to sound "great", not just "average".Didn't mean to hijack the thread, but I thought: what's the point of copying Avalon, when it looks like they're just staking their name on the Thiel speakers that they use?
CM
Ceramicman
Agree with what you say there about shape of cabinet. Unless you are in love with the shape of the Avalon cabinets, I think there are better ways of maximising things like imaging from using a narrower baffles like B&W 801 / 802 style of smaller mid and treble cabinet section, with large woofer in separate cabinet.
A small 12cm wide C79 mid and 10cm tweeter frame could easily fit into a 15cm wide separate enclosure, which could be better than the Avalon 30cm wide shapes in what are really still large boxes with corners angled.
Agree with what you say there about shape of cabinet. Unless you are in love with the shape of the Avalon cabinets, I think there are better ways of maximising things like imaging from using a narrower baffles like B&W 801 / 802 style of smaller mid and treble cabinet section, with large woofer in separate cabinet.
A small 12cm wide C79 mid and 10cm tweeter frame could easily fit into a 15cm wide separate enclosure, which could be better than the Avalon 30cm wide shapes in what are really still large boxes with corners angled.
tbla said:
No ???
I just like to "draw" some attention to my ongoing project "Gydinel" As you can see this a DIY project inspired by the Avalon Sentinel.... I started with the C-12 and just reviewed the Diamond tweeters D-20.....
check all about it on www.dddac.de
Would also be interested in feedback on others who used the diamond version !!!
Next stage is active filtering with Linkwitz Riley 24dB tube filters...
Doede
fdegrove said:Hi,
Yes you can and as I probably know the Avalons and Guidos' speakers better than most, I can only say that the Guidolons some very close indeed.
Cheers,
P.S. Doede, you know Guido too, right?
Hi Frank,
of course I know Guido, as he built the enclosures of the Gydinel !! Real golden hands on the woodwork....
take care
doede
Let's revisit this thread
Since the last posting a lot has happened on the Avalon cloning...
On my surfing I stumbled on this thread and I figured you all would like to see these allso
Some stunning results and projects can be vistited here:
Tony Gee's (e.o) Soup
Erik van Voorst's xXx and xXx, discussion thread (Dutch)
Marc Heijligers
Maybe you all start to mouthwater like me...
Since the last posting a lot has happened on the Avalon cloning...
On my surfing I stumbled on this thread and I figured you all would like to see these allso
Some stunning results and projects can be vistited here:
Tony Gee's (e.o) Soup
Erik van Voorst's xXx and xXx, discussion thread (Dutch)
Marc Heijligers
Maybe you all start to mouthwater like me...
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