Guest Posted December 7, 2001 Report Share Posted December 7, 2001 All,Those of you that know the TSW series know their tweeters are one of the series' best features. They all used the same 3/4" titanium dome tweeter, except for the 910 (and 810) that used a 1" driver made by MB Quart (and the TSW-100 which used a 3/4" poly tweeter). Well, my newly aquired pair had fried tweeters and I wasn't satisfied that the solution sold by Layne Audio and AB Tech was the best that could be done. The problem is there are no longer any direct replacements and there are no parts available to do a proper rebuild. Funny AR couldn't do a better job of having *real* replacements for a longer period of time for a pair of speakers that cost aorund $2500 in the late 80's!So, I contacted MB Quart...why not? They're the OEM anyway. I e-mailed and the *next day* received an e-mail from a technical manager asking for pictures of my tweeters so he could research what they could do for me....I was hoping for a rebuild. Well, no rebuild is possible however, MBQ currently makes tweeters that are a nearly perfect acoustic and electronic replacement for the TSW tweeter. The problem is the custom faceplate that the TSW tweeter uses and the fact that the dome and voice coil are integral to the faceplate. This would normally mean that you'd have to do what AB Tech/Layne Audio have done...mount a similar current tweeter on a plate that *approximates* the shape of the TSW faceplate. No offense, but I think it's ugly.The TSW faceplate is attached to the magnet assembly with four bolts. Oddly enough the spacing for those bolt holes is exactly the same on the current tweeters as on the old. So, the plan is to take the AR faceplate, remove the cone, surround, and voice coil (which I've done so there's no going back!), and bolting the AR faceplate (with slightly longer bolts) in front of the new tweeter's stock faceplate. So, you'd have the AR faceplate in front, the MB Quart faceplate (with new dome, etc. attached) behind that, then the magnet assembly...all three held together with slightly longer screws. The gentleman at MB Quart did some measurements from the pics I sent and it should be a nearly perfect fit and replacement. The tweeters (and all other MB Quart stock) are unfortunately in transit in a warehouse move so I won't be getting them for about three weeks or so. These particular tweeters aren't available retail as they are produced as an OEM product for about 20 current speaker manufacturers. I am assured by the contact at MB Quart that they are absolutely the most appropriate replacement for the tweeter they manufactured back in 1985-89 for the TSW series.I'll be taking a full picture spread and writing up a document with diagrams to be posted here on the site, assuming all goes as we have planned it. I'll also post a follow-up here. Also, assuming everything goes well, I'll be able to pass along the gentleman's name at MB Quart as he said that he would welcome hearing from anyone else who wanted to replace their TSW tweeters.Hopefully, if this goes as planned, TSW-910/810 owners will have a better option for tweeter replacement and spare parts for years to come since MB Quart will make this tweeter as long as there is OEM demand for it...and there's plenty since MB Quart sells them several thousand at a time.Wish me luck! :-)Keith Link to comment Share on other sites More sharing options...
Guest Posted January 8, 2002 Report Share Posted January 8, 2002 Hi Kieth - great to hear you've tracked down a source of replacements. But in the quest to maintain the cosmetics, have you considered the possible sonic effects of the 'faceplate sandwich' ? On the TSW tweeters, AR made a big deal about their acoustic lens design and faceplate shape. Burying the dome behind an extra faceplate might change loading on the dome, or at least radiation into the room. But then again, if there is a bad effect, the extra bits can always come off again... (I'm still enjoying my 510's....)Phil. Link to comment Share on other sites More sharing options...
Guest Posted January 10, 2002 Report Share Posted January 10, 2002 >Hi Kieth - great to hear >you've tracked down a source >of replacements. Funny you should reply a couple of days ago. I just got the new tweeters today! And, they have been summarily hacked up and installed. Kinda creepy taking a Dremel to the faceplate of a brand new freshly delivered $70 tweeter! :-) Quite a difference now that the 910s are sealed again (I didn't mod the cabinets for my temporaries). These tweeters are a lot smoother than the ones I was using from my 510s. I did have to cut a little relief in the tweeter hole since the terminals were in slightly different places. Ahem. That was the messy part.>But in the quest to maintain the cosmetics, have you >considered the possible sonic effects of the >'faceplate sandwich' ? Yes, I have thought about it...but, given that the tweeters being installed aren't AR stock, there'd a be a sonic difference of *some* sort anyway. So, given that there isn't *anything* that can *exactly* replace the originals, I'll go with the cosmetic improvement as well. Regardless, the AR lens woudn't be crap anyway. Actually, I think off-axis response is a bit better as I walk around the room with something familiar on. Who knows.My contact at MB Quart said that the additional <1/8" extension due to the faceplate sandwiching wouldn't be a problem. He looked at pics of the AR faceplate to determine that. I did remove the mesh screen from the MBQ tweeters so they're a little more open or airy than designed. If the increased distance from the faceplate attenuates them a bit it might be a wash.Finding the !@#$%^&* 4mm x 10mm screws to account for the increased depth was the hardest thing! I also took pics of what I did but my damned digicam burped or something...some of the images are only half there. There's enough to get the flavor of what I did. It was just a lot of Dremel work on the old faceplates and cutting down the new faceplates to fit. I can't wait to send them to the guy at MBQ...he'll probably drop out of his chair when he sees what I did to *his* tweeters! :-)I'll try to get a document together and to Mark sometime soon.Later!Keith Link to comment Share on other sites More sharing options...
Guest Posted February 10, 2002 Report Share Posted February 10, 2002 A bit of clearing up: Please don’t fault us for the way the AR adapter plate setup looks, we had nothing to do with it. Just be glad that there is a factory option at all. The AR provided TSW-910 / 610 replacement tweeters are old stock MB Quart tweeters of the exact same type/spec as the “special” AR version, only difference is the faceplate. You could hack up and re-mount the old spec tweeter to your AR faceplate if you wanted to, just as you did with the new type tweeter.Sound issues: The lip created by back mounting the tweeter will cause a notch in the frequency response, but this should be fairly minimal. There is a way to back mount the tweeter flush and not have the lip, but it would take some very exact machining of the old and new faceplates. If using the new production tweeters, you’d do well to tweak the crossover to better match them [but do so ONLY if you have experience in such things, these tweeters are WAY too pricey to risk frying]. If someone would care to draw up a schematic of the 910 crossover I could probably work out an add on resonance trap filter to knock off the metal dome’s HF peak [the new ones still have it, its just not as pronounced].Mounting Problems: The way the MBQ tweeters are made, the diaphragm assembly is made directly onto the back of the faceplate rather than a separate replaceable sub-assembly, preventing a simple diaphragm swap. Having MBQ tool up to produce more diaphragms with the custom shape faceplate would cost many thousands of dollars, so it’s not going to happen. There are so few of the TSW 610 / 910 speakers around the demand for the tweeters is very low. If they were made, the cost per-piece would be so ridiculously high no one would use them.To put the custom faceplate vs. adapter plate cost into perspective, in the past we have approached two different European manufacturers about having custom 4.75” diameter faceplates made to match the classic AR ¾” tweeter used in the 3a/ 9/ etc., we were quoted $8,000 for the tooling costs alone, not to mention huge initial orders required [1000+ pieces]. Having high grade ABS sheeting machined into simple adapter plates would cost about $5 each with under $100 in setup costs, minimum order of about 100 pieces. Modifications: AR selected the MBQ tweeters for the 610 / 910 because they were the best available metal domes of the day. They weren’t exactly the smoothest tweeters ever made, and though new versions are a bit better they are still on the bright side. In the late 80’s when MBQ metal domes were very popular, DIY speaker builders routinely coated the metal domes with damping compounds to tame their resonance peaks. A properly applied coat of thinned down rubber cement or latex cloth surround sealer could work wonders. Coating the underside of the dome doesn’t work quite as well, but it doesn’t require prying off the metal screen. Link to comment Share on other sites More sharing options...
Guest Posted April 9, 2002 Report Share Posted April 9, 2002 >A bit of clearing up: Please don’t fault us for the way the >AR adapter plate setup looks, we had nothing to do with it....Agreed...sorry, my angst was really directed at AR for not putting more spare parts for a $2500 (in 82-84 dollars) pair of speakers into the system. I mean, how many 910s could they have sold? (I'd really like to know actually!...anyone?)>Sound issues: The lip created by back mounting the tweeter >will cause a notch in the frequency response, but this >should be fairly minimal. My contact at MBQ agreed, there, but minimal. Certainly less than my old tired ears could detect.>There is a way to back mount the >tweeter flush and not have the lip, but it would take some >very exact machining of the old and new faceplates.Well, if by machining you mean a Dremel...yeah, I "machined" a *bunch* of plastic off of the backside of the original faceplate to get the new faceplate to mount flush to the back of the old. I didn't think it was too bad though...remember, the old faceplate just ends up being a cosmetic additon to the new tweeter assembly. Most of the removal from the old faceplate was the terminal posts. From the new faceplate all the excess flange was removed, right down to a very, very close trim on the new terminals. It took about 90 minutes per tweeter of some really big hacking (to remove the majority of the excess plastic), and some very fine work (around the new terminals) to finish. The cabinet also required modification since the terminals were not in the same place as the old. Some relief had to be cut in the MDF. Actually, the hardest thing for me was finding appropriate 4mm cap screws that were long enough but not too long to make up for the additonal faceplate!>If using the new production tweeters, you’d do well to tweak >the crossover to better match them [but do so ONLY if you >have experience in such things, these tweeters are WAY too >pricey to risk frying]. If someone would care to draw up a >schematic of the 910 crossover I could probably work out an >add on resonance trap filter to knock off the metal dome’s >HF peak [the new ones still have it, its just not as >pronounced]. Now, that's something I'd be unwilling to do, but would consider if someone experienced like yourself was doing the work. :-) Unfortunately I'd be no better at drawing the crossover as I would be at translating ancient Egyptian hieroglyphics.>Mounting Problems: The way the MBQ tweeters are made, the >diaphragm assembly is made directly onto the back of the >faceplate rather than a separate replaceable sub-assembly, >preventing a simple diaphragm swap. Having MBQ tool up to >produce more diaphragms with the custom shape faceplate >would cost many thousands of dollars, so it’s not going to >happen. There are so few of the TSW 610 / 910 speakers >around the demand for the tweeters is very low. If they were >made, the cost per-piece would be so ridiculously high no >one would use them. You mean $500-$1000 each is too much? :-).>To put the custom faceplate vs. adapter plate cost into >perspective, in the past we have approached two different >European manufacturers about having custom 4.75” diameter >faceplates made to match the classic AR ¾” tweeter used in >the 3a/ 9/ etc., we were quoted $8,000 for the tooling costs >alone, not to mention huge initial orders required [1000+ >pieces]. Having high grade ABS sheeting machined into simple >adapter plates would cost about $5 each with under $100 in >setup costs, minimum order of about 100 pieces. Wow, $8K is a lot...would it not be less from domestic manufacturers?>Modifications: AR selected the MBQ tweeters for the 610 / >910 because they were the best available metal domes of the >day. They weren’t exactly the smoothest tweeters ever made, >and though new versions are a bit better they are still on >the bright side. In the late 80’s when MBQ metal domes were >very popular, DIY speaker builders routinely coated the >metal domes with damping compounds to tame their resonance >peaks. A properly applied coat of thinned down rubber cement >or latex cloth surround sealer could work wonders. Coating >the underside of the dome doesn’t work quite as well, but it >doesn’t require prying off the metal screen. Is this something you'd really recommend? I did remove the screen at the urging of MBQ so I have access to the front of the dome...And, again, sorry if I implied that you *personally* were responsible for the factory replacement.Thanks!Keith Link to comment Share on other sites More sharing options...
Guest Posted November 3, 2002 Report Share Posted November 3, 2002 Hi, do you think there are replacement speakers for the TSW-510 cabinets; reasonably priced? Mine are rotted really bad, don't understand it either. Even the foam on the cabinet front is rotted. Or is it better to dump these and get new speakers? Link to comment Share on other sites More sharing options...
Guest Nigel Posted November 4, 2002 Report Share Posted November 4, 2002 >Hi, do you think there are replacement speakers for the >TSW-510 cabinets; reasonably priced? Mine are rotted really >bad, don't understand it either. Even the foam on the >cabinet front is rotted. Or is it better to dump these and >get new speakers? 510's are worth rebuilding.Nigel Link to comment Share on other sites More sharing options...
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