I asked in an earlier thread
http://www.diyaudio.com/forums/multi-way/202967-copy-proac.html
if the ProAc Response 2.5 can be successfully cloned, and the consensus was that though smart people worked hard at it, the clones did not duplicate the ProAc Response 2.5.
Why did the Response 2.5 clones fail?
Thanks.
http://www.diyaudio.com/forums/multi-way/202967-copy-proac.html
if the ProAc Response 2.5 can be successfully cloned, and the consensus was that though smart people worked hard at it, the clones did not duplicate the ProAc Response 2.5.
Why did the Response 2.5 clones fail?
Thanks.
You can find an extensive article from Troels here: http://www.audiokit.it/itaeng/Altoparlanti/ScanSpeak/The 2.5 clone paper.pdf
Beautiful speaker though, I remember admiring them when I was a kid reading stereophile.
Thanks. I've read a lot by Troels, and he apparently provides a lot of great engineering advice, but I've never seen him say "I put my clone next to the real 2.5 and they were identical."
What is so hard about reverse engineering a speaker when you can get the exact, original drivers? Surely a crossover schematic is available or doable? Everyone seems to be nailing the boxes, this doesn't seem difficult either.
I just stumbled on this old posting..
They didn't fail!
I have fair amount of experience, to back it up, if anyone cares to listen..
To bring up an old thread yet again, they are still my main speakers, except that the original design did fail. I replaced the tweeters and Troels was kind enough to design a crossover for me, as I think he did the same during his experiments. The original clone design was too sibilant, and I think Proac did something with the drivers (or had ScanSpeak do it) to make it work. That was the part that wasn't cloned.
I put the original tweeters from the clone into a bastardized MurphyBlaster and they sound just fine for where they are in my son's dungeon of a bedroom.
I put the original tweeters from the clone into a bastardized MurphyBlaster and they sound just fine for where they are in my son's dungeon of a bedroom.
Was half-asleep then. For greater clarity, IMHO, likely explanations include:
1) The notion that clones can't compare to the original invariably manifests as a preconceived bias against cloned designs. Most likely explanation IMHO, given how closely the FR of clones and the original have tracked each other.
2) The cabinets in DIY iterations are slightly outside of Proac's tolerances in terms of material used and cabinet size, causing a difference in cabinet resonance. There may also be significant deviation in cabinet volume, altering tuning.
3) Proac flat out uses tweaked drivers rather than stock ones. Alternatively, the SS used in clones don't undergo a selection process to keep T/S parameters close to spec. This is founded on the presumption that the drivers used, despite being SS, can exhibit significant deviation to require selection from bulk. Not really likely.
Lots of postulates, but the first one seem most likely by far.
1) The notion that clones can't compare to the original invariably manifests as a preconceived bias against cloned designs. Most likely explanation IMHO, given how closely the FR of clones and the original have tracked each other.
2) The cabinets in DIY iterations are slightly outside of Proac's tolerances in terms of material used and cabinet size, causing a difference in cabinet resonance. There may also be significant deviation in cabinet volume, altering tuning.
3) Proac flat out uses tweaked drivers rather than stock ones. Alternatively, the SS used in clones don't undergo a selection process to keep T/S parameters close to spec. This is founded on the presumption that the drivers used, despite being SS, can exhibit significant deviation to require selection from bulk. Not really likely.
Lots of postulates, but the first one seem most likely by far.
Last edited:
I generally agree with what you are saying. In my case though I hadn't actually ever heard the originals, so when I was finished with my build I just didn't like the sound, too sibilant as I previously posted. I replaced the tweeters with a higher priced SS, the 9500, and was much more pleased with it. I probably didn't build the cabs exactly to spec, mostly because I had a contractor friend cut the panels, and contractors are notorious for cutting things "close enough". And there was some talk of treating the tweeters with damar varnish, which I did, but who knows if that was what Proac did.
All in all though, "Dazed and Confused" by Led Zep just finished playing and it sounded pretty damn good. I listen to everything though, not just loud rock, and it all sounds good.
Yes, an exact copy can be built. I've built 3 pairs and had a friend with the actual R2.5
At this point in time, and with everything that's available on this forum You can design a better speakers than R2.5 or possibly any speaker on the market for that matter. Learn Xsim and design a speaker suited to your own room and taste. you'll never look back.
Longgggg time lurker. I bought 2.5's new (one of the last off the line - the D25's had just hit the stores, so the 2.5's were reduced) and still have them, unmarked, and have never worn the grills, so no uneven fading.
I've been lurking on this and other threads since I bought them 12? 13? 14? years ago.
Back then, while I had electronics experience, I had no carpentry skills (and no money or tools), and building clones was just a fantasy. Different decade. Different circumstances. I've been building kitchen and bathroom cabinets and counters, and building dining furniture. I'm good to go.
I recently bought a ProAc CC2 to go with the 2.5's. And now I'm looking for some rears to make a surround sound system. Now, I could go the lazy (and probably cheaper, and certainly better resale) route and buy some 2.5's on eBay, or I could go the more gratifying route and build clones.
Or... I could start over. There are some ebony D30R on eBay for $3800, a rather useful saving from the RRP of $8800. But then I'd need to get the ProAc Dcenter and still need some rears, so back to plan A. Though I guess that depends on the definition of "need".
I could get bookshelf speakers, but I don't have shelves, so the stands they'd need would take up more space than the full size 2.5's.
Ideally I'd match with bipolar or dipolar speakers, but unless I've been walking around with my ears and eyes closed (possible!), there are no surrounds matched to the 2.5's. So after rambling on, that would be my challenge. Can I sensibly design (or plagiarize if someone's already done it) some bi- or di-polar surrounds to match my 2.5's ? If I work with Xsim, will that get me to the right end-point, or is that a wild goose chase?
I've been lurking on this and other threads since I bought them 12? 13? 14? years ago.
Back then, while I had electronics experience, I had no carpentry skills (and no money or tools), and building clones was just a fantasy. Different decade. Different circumstances. I've been building kitchen and bathroom cabinets and counters, and building dining furniture. I'm good to go.
I recently bought a ProAc CC2 to go with the 2.5's. And now I'm looking for some rears to make a surround sound system. Now, I could go the lazy (and probably cheaper, and certainly better resale) route and buy some 2.5's on eBay, or I could go the more gratifying route and build clones.
Or... I could start over. There are some ebony D30R on eBay for $3800, a rather useful saving from the RRP of $8800. But then I'd need to get the ProAc Dcenter and still need some rears, so back to plan A. Though I guess that depends on the definition of "need".
I could get bookshelf speakers, but I don't have shelves, so the stands they'd need would take up more space than the full size 2.5's.
Ideally I'd match with bipolar or dipolar speakers, but unless I've been walking around with my ears and eyes closed (possible!), there are no surrounds matched to the 2.5's. So after rambling on, that would be my challenge. Can I sensibly design (or plagiarize if someone's already done it) some bi- or di-polar surrounds to match my 2.5's ? If I work with Xsim, will that get me to the right end-point, or is that a wild goose chase?
It's not a wild goose chase, but you will be herding cats. It takes a lot of experience to recognise what creates the 'signature' of a speaker's sound, especially if(as in surrounds) the placement will be different.
A place to start would be REW measurement from your listening position. If you get the common bandwidth to look the same you may be part of the way there. From there you try to find problems, notes that bother you in one set versus the other, and work on them.
Troels often warns about reading too much into measurement(usually on-axis), and the 'power response'(the way the sound fills the room) can be very different with similar on-axis response, thus changing the tone.
I'm not trying to discourage you, a good problem to work on is a good thing to have, we can learn from it, and it keeps us out of trouble.
A neat tool is the use of 360 degree pan recordings, they can help you find notes that need adjusting, they used to be sold as lps and discs, I'm sure some are on the web.
A place to start would be REW measurement from your listening position. If you get the common bandwidth to look the same you may be part of the way there. From there you try to find problems, notes that bother you in one set versus the other, and work on them.
Troels often warns about reading too much into measurement(usually on-axis), and the 'power response'(the way the sound fills the room) can be very different with similar on-axis response, thus changing the tone.
I'm not trying to discourage you, a good problem to work on is a good thing to have, we can learn from it, and it keeps us out of trouble.
A neat tool is the use of 360 degree pan recordings, they can help you find notes that need adjusting, they used to be sold as lps and discs, I'm sure some are on the web.
Thanks, Boswald.
I just had a quick look at REW and see I need a calibrated microphone. I don't have one, but do have what might be the next best thing - an Audyssey microphone, which are all designed to be similar to one another, and someone else's calibration curve from the internet. I won't cross link to another forum here - it seems bad manners.
It'll give me something to play with this afternoon when the family goes out
I just had a quick look at REW and see I need a calibrated microphone. I don't have one, but do have what might be the next best thing - an Audyssey microphone, which are all designed to be similar to one another, and someone else's calibration curve from the internet. I won't cross link to another forum here - it seems bad manners.
It'll give me something to play with this afternoon when the family goes out