Matching Replacement Woofers


Here's a question that will betray my complete ignorance of physics, electricity and quite possibly everything else that matters in the world.

I recently purchased a pair of speakers, only to find one has a blown woofer. Unfortunately, the speaker company is out of business, so a replacement is not available. I would like to replace the woofer, and assume it would be best to replace its mate in the other speaker as well, so the two speakers will sound similar. However, assuming - and this is where my stupidity shows up - that in any speaker system the sensitivity of the woofer must be matched with the other drivers (midrange, tweeter) so they have a cohesive sound, how can I know whether a replacement woofer will have a similar enough dynamic output to the woofer its replacing to pair well with the other drivers? If that question makes sense to anyone but me, I'd appreciate hearing how best to select replacement woofers for consistency in tone (a pipedream, I'm sure!) and most importantly, dynamic output. Also, in terms of frequency range, is there a significant difference between good quality bass drivers of the same dimension, or is frequency range more a function of cabinet design? Thanks much!
128x128balthus
Yes, you caught me out. I er, "stretched the truth" in saying the company was out of business because it seemed the easiest way to avoid mentioning them by name...guess I shot myself in the foot with that one! In any case, I am corresponding with the company now about the possibility of replacing the woofer, and I'll see how that progresses before requesting further assistance. Thanks again, Ben
Mr B- In the initial post, it sounded like the manufacturer of the speaker system was out of business. Then too: I doubt many would blame the company for abuse that the system suffered at the owner's hands, as most woofers are blown/damaged by being overdriven. Either way: mentioning the company's name would hardly affect their status in the audio community. As Mr. G suggests; if we knew the brand/model of the system; there's an excellent chance that someone in here could help find a solution.
Would the specs of the existing good woofer be printed on the back of the driver?
Probably not. Its ref number might be.
Please note that there are very few companies that make their own drivers; especially small companies.
If the company still exists, by all means access their d-base, or ask, for the driver specs. These are necessary to find a suitably matching product in the market.
Failing that, you have to get the driver measured -- not simple. You might as well mention the spkrs name & model, maybe someone else has already been there, done that!
Hmmm, some food for thought, thanks. However, I may have led you a bit astray by failing to mention that the blown woofer is no longer present, i.e. I don't have it any more. Also, the woofer is proprietary, made by the speaker company and not purchased by them from a supplier.

Reading your responses, it seems the consensus is that the sound and sensitivity of replacement woofers would vary from the original, but with luck and careful matching it may be possible to find a replacement close enough to be suitable. Fair?

In any case, the suggestion of speaking to Madisound sounds like a reasonable place to start. Would the specs of the existing good woofer be printed on the back of the driver? I'd prefer not to remove it from the cabinet to check unnecessarily. (Just guessing the speaker company may not be too forthcoming about their woofer specs, since I'd be using them to purchase a replacement from someone else!)

Just f.y.i., not to be too mysterious about this, but I do prefer not to mention the brand of speaker, as my experience is that any remarks voiced on audiogon about an audio product that can be construed (or misconstrued) as critical can have quite serious consequences for the company, especially if it is a small one. And also for the owners of their products. I like the speakers, don't blame the company for the woofer failure, and prefer not to have their name brought up in a negative context not of their making. Whew, that was a mouthful!

Thanks again for your thoughts!
Many of the companies out there are using drivers from just a few companies such as Vifa or Seas. Ask Madisound or speakercity for a replacement. You should either recone both or replace both.
Mr T- Because Waldom is the only manufacturer of reconing parts, outside of the companies that distribute kits to their warranty stations(mostly just for pro drivers; ie: Gauss Cetec, JBL, EV, Altec, etc.). At least; that's the way it was when I had my shoppe. As far as I know; no one else has ever given Waldom any reconing parts supply competition, at least in this country. Then again- it's been a while.
Rod,how can you say ALL reconers use Waldom Electronics parts?Just curious.
buddy of mine replaced stock watt puppy woofer with an aftermarket part...diff surround, diff material, but could not tell any diff in sound (whereas we can and do hear big diffs w/ plating on AC plugs).

just get the specs right and you should be fine.
Unfortunately- ALL reconers use Waldom Electronics parts with which to recone woofers(unless they are a warranty repair service for the driver in question). The chances of their using a voicecoil, spider and cone combination that would actually match(or come close to) the Thiele/Small parameters(even simply the efficiency) of the original are slim to none. Many manufacturers have built systems, using drivers from suppliers such as Audax, Peerless, SEAS, KEF, Eminence, Rola, etc. and IF there is any info of the woofer's magnet or frame(usually numeric); you might be able to still get an exact match. Contact either Millersound(http://www.millersound.net/indexfl.htm) or Madisound(http://www.madisound.com/) with whatever info you find, and inquire.
Technically, there is a difference between all drivers. Driver frame, cone, coil materials all play very important and unique roles in the reproduction of sound. Add this to the cabinet design, type, and materials used AND the crossover interaction between all the drivers, and you have many different outcomes. My suggestion is to have BOTH drivers sent to a reputable shop to have them re-coned.
Alternatively, check out the manufacturer of yr spkrs woofer, and go to Madisound dot com, and ask for a suitable replacement. Madisound is a well stocked e-shop and has a forum where spkrs designers lurk.
Just have the blown woofer reconed/refoamed. Much better to use the exact woofer model when you can. See links below for these services.

www.simplyspeakers.com

www.millersound.com