Low-Cost Sonus Faber Clone

[johnnyb831]

Currently I'm working on a clone of the Sonus Faber Cremona (http://www.polkaudio.com/images/showcase/56_37_big.jpg). My plan is not to use the Scanspeak drivers ($$!!) that they use. Instead, I'm trying to find similar drivers, possibly somewhat acceptably worse, at a much lower cost.

Here are the drivers I've selected:

Tweeter

Sonus Faber's Selection (they use a custom phase plug & faceplate):
http://www.madisound.com/catalog/pro...oducts_id=1581

Knock-off Equivalent (you all know it):
http://www.madisound.com/catalog/pro...oducts_id=1181

Midrange

Sonus Faber's Selection:
http://www.madisound.com/catalog/pro...roducts_id=924

Knock-off Equivalent (the W14RC25-04ohm):
http://www.madisound.com/silverflute.html

Woofers

Sonus Faber's Selection:
http://www.madisound.com/catalog/pro...roducts_id=930

Knock-off Equivalent (discontinued...might be a problem if I don't order soon):
http://www.madisound.com/catalog/pro...oducts_id=1112

One of my issues is that I can't find an accurate frequency response graph of the silver flutes, because the graph listed on madisound is boxed. I've just sort of accepted that the xt25's response is not as smooth and broad as the ss driver. Also, the Vifa woofer has a significantly larger vas, which may or may not be an issue.

Any suggestions?

[Ap]

I dont think you'll come anywhere near Sonus Faber with those drivers. If you are going to spend all the time and effort making cabinets like them then spend the money on drivers.
I know Scanspeak revelators are pricey so I would look into using Peerless HDS or exclusives, Aurum Cantus or even Dayton RS series.
Andrew.

[chrismercurio]

is similar to what you have chosen as the "knockoff". It's also a very good tweeter IMO having heard it in several designs. The revelator is used in the Homage line

You may want to reevaluate where you are going with this. Without proper measuring equipment, solid math skills, and simulation software it is difficult to do anything. I don't know your background but if this is a first project, you may want to go with someone else's proven 3-way. Troels has several using high quality parts...in fact I wouldn't be surprised if a few of them outdid the SF you are trying to emulate.

http://www.troelsgravesen.dk/Diy_Lou...r_Projects.htm

[John Nail]

HI,

I am fairly new to this forum, though I am not new to DIY speaker building. No matter what anyone else says to the contrary, I wouldn't discount the Silverflute W14 out of hand as being inferior. It actually has a pretty detailed presentation, and if you apply a coat of so of Wet Look Black, to help damp the upper region resonances, put it in a sealed enclosure, then it is a very competent little performer. You might also want to take a look at the Silver Flute W20 8 ohm drivers.....the posted specs on these woofes are not really close to the actual....though some of the specs are relative in the same park.
I have 4 of those units, have measured each one after breakin (200 hours), and the specs put a pair of them in a 2 cu.ft. vented enclosure, tuned to 35hz, and having an "in room" F3 in the mid to upper 30's......NOT the 60+hz F3 that the specs on the MADisound page would indicate.
Using this woofer, with similar cone treatment of the Wet Look black would then give you a better chance at getting a seamless bass/midrange integration, since being made of the same cone material, there won't tend to be any voicing problems along those lines. That leaves only the crossover integration to worry about. Don't underestimate those drivers.....for what they are, and at the price point they are, they are one of the best bangs for the buck. Take a look at the Revelator woofers......how much is the factor of price between the SF and the ScanRev? About 5-7 times the money? I have heard both, and while the ScanRev is the best of the two, I would have to say it isn't 5 times the driver in the performance issue....beyond a certain point.....only until you get way into the max power application do you really start to see the differences in distortion.....and how much of that is really audible is subjective.

John

[johnnyb831]

Originally posted by John Nail
HI,

I am fairly new to this forum, though I am not new to DIY speaker building. No matter what anyone else says to the contrary, I wouldn't discount the Silverflute W14 out of hand as being inferior. It actually has a pretty detailed presentation, and if you apply a coat of so of Wet Look Black, to help damp the upper region resonances, put it in a sealed enclosure, then it is a very competent little performer. You might also want to take a look at the Silver Flute W20 8 ohm drivers.....the posted specs on these woofes are not really close to the actual....though some of the specs are relative in the same park.
I have 4 of those units, have measured each one after breakin (200 hours), and the specs put a pair of them in a 2 cu.ft. vented enclosure, tuned to 35hz, and having an "in room" F3 in the mid to upper 30's......NOT the 60+hz F3 that the specs on the MADisound page would indicate.
Using this woofer, with similar cone treatment of the Wet Look black would then give you a better chance at getting a seamless bass/midrange integration, since being made of the same cone material, there won't tend to be any voicing problems along those lines. That leaves only the crossover integration to worry about. Don't underestimate those drivers.....for what they are, and at the price point they are, they are one of the best bangs for the buck. Take a look at the Revelator woofers......how much is the factor of price between the SF and the ScanRev? About 5-7 times the money? I have heard both, and while the ScanRev is the best of the two, I would have to say it isn't 5 times the driver in the performance issue....beyond a certain point.....only until you get way into the max power application do you really start to see the differences in distortion.....and how much of that is really audible is subjective.

John

Wow, thanks. I've been looking for some good info on the Silver Flutes. You just about summed up all I could ask for..

[Ap]

Well I didnt really want to knock Silver Flute drivers & I'm sure you might be able to get them working well, my point is to go for drivers which are known to give good predictable results (both Peerless & Seas come to mind) as you mentioned "the posted specs on these woofes are not really close to the actual....though some of the specs are relative in the same park." - to me this means you will require measuring capabilities to work with them.
Andrew.

[John Nail]

Whether you are using Silverflute drivers, Dayton classics, SEAS, Excel, Scanspeak, or any other driver, no matter what the cost is, you should always measure the t/s parameters of the units you purchase after breaking them in. Silver Flutes aren't the only manufacturers out there who post somewhat "off" parameters from the production stuff you buy. All manufacturers tend to make small running changes, yet they don't always update the measurements and specs. to reflect the changes. Most times, even though some of the specs are altered, the end result is virtually the same needed enclosure volume.....but there are alot of instances where the box volumes required are quite a bit off. I have run across several models of Peerless CSX in the past, as well as SEAS, and even a couple the higher end Focals...not to mention at least one Scanspeak model that measured differently from the advertised spec.....and not just one or two small differences in every model I found.....some had rather spread out differences, but took the same box volume, while others required a larger or smaller box than what the advertised specs would have indicated.
So, it is ALWAYS good to measure for t/s parameters for the drivers you buy, and will be designing for. It just makes your design all the more accurate. As for not having t/s parameter measurement capabilities......I wouldn't understand anyone's train of thought who was willing to spend several hundred $$ on certain drivers, but wasn't willing to spend about $160 on a Woofer Tester 2, or WT3 which is slated to be $100 at PE. Knowing that the actual data on the drivers could vary, and spending so much on those drivers, does it make sense to get sloppy or inaccurate in the enclosure design? The enclosure is 1/3 of the total design. A wrong enclosure can make a speaker bad, just as a badly designed crossover can do the same thing....even using the "uber" drivers from Scanspeak doesn't ensure a good design. Only careful and accurate measurements and careful design can make for a good speaker.

John

[nate]

Hey there Johnny,

I live in Redmond as well and my buddy could probably test your drivers for you for cheap. He has a very good measurment system.

I actually began my speaker building addiction dreaming of building a Cremona clone as well.....

After much contemplation, I went in a completely different direction. Instead of trying to copy the cremona I bought drivers for a simple two way:
Accuton C23/6
Eton 7-372

These were expensive then and they are still expensive now, but they were very easy to design a crossover as the drivers are both well behaved and operating well within their comfort zone.

I'm not suggesting that you drop a s&*t-ton of money on drivers. My decision not to build the clone was based on the fact that even if I bought the closest commercially available drivers to the cremona, my creation would never be a bargain version of the cremona. It would just be a three way in a box. The Cremona is a good commercially available speaker, but they aren't that good.

I would pick a good Seas 6.5" midwoofer and tweeter and I'll set up a time so that you can get them measured and we can work up a crossover. You can p.m. me if you want.

Best of luck

Nate
chiconate@hotmail.com

[johnnyb831]

Hey, sounds great. I'll drop you a PM when I'm ready (starting a job at Expedia tommorow). Good to know theres some audiophiles in my area.

[Ap]

Thanks John,
I had wrongly assumed Seas & Peerless etc drivers would be close to spec, looks like I should go & get some measuring gear!
Andrew.