ChrisM

If you haven't ordered the woofers yet, I would say don't. Unless price is no object this isn't worth it. https://www.madisoundspeakerstore.com/audax-soft-dome-tweeters/audax-tw034x0-1.3-textile-dome-tweeter-by-aac/ And you should get two because they aren't exactly the same as the original model. With a 6db per octave crossover even at 3KHz you can't just stick in a "normal" 1in. dome tweeter. This might be OK but because it is 4ohms you'd have to change the crossover cap and maybe add a resistor. There may also be some impedance issues at the crossover. https://meniscusaudio.com/product/sb-sb29sdac-c0004/

The "trade" was a joke; germs for speakers? Anyway, I don't think I'd want to spend $50 + shipping for just the drivers. Also, there is a possibility of damage unless buried in bubble wrap which then might not fit in the box. Sorry but I'll have to pass. Thanks though.

Assuming you used RoyC's sealer and assuming you put on too much, you need to get some toluene and a clean cloth. Saturate a spot on the cloth with the toluene and gently wipe the surround. The sealer should dissolve a bit and come off on the cloth. Work your way around using fresh parts of the cloth as you go. This is assuming there's too much so do the tests as RTally said first.

Nonsense! Oh wait, you're probably right but why should that stop me?? Enquiring minds.... The QA at KLH did leave something to be desired judging from all the ones I have and ones I've worked on for others. Henry's performance target seems to have been within a price target. I keep hoping some ancient ex-KLH person will come out of the woodwork and enlighten me. Over on the preeminent KEF site there are a few ex-KEF guys who hit us over the head with facts all the time. It has more of an engineering bent than CSP. What's sort of amusing is that I am a total "B" type personality; definitely "Oscar" not "Felix". The only thing I'm OCD about is speakers and I don't know why. No detail too small to get my undivided attention, etc etc.? Thanks, Chris

Well then, I guess my little discoveries are elevating me to the vanishing breed of KLH experts.? I have talked to RoyC about surrounds a few times but not about this 12.5 issue. Maybe he'll chime in. No problemo but you might keep your eye out for the cloth ones. I haven't performed any other measurements other than the initial ones where I discovered the lower Fs. Hopefully someday.....

So no one has any insight on this? ra.ra said add pictures. I did and nada. I realize this forum is mostly about restoration not the technical aspects of the speakers but correct restoration does depend on using the correct drivers. Maybe if this was about AR's it would get more traction.

Best way to improve 901's is lighter fluid and a match.?

If nobody wants the whole thing I'd be interested in just the parts. Selling it whole is better but if you don't get any bites let me know. Rectilinear parts are hard to come by in the Northwest. We have lots of coronavirus but few Rectilinears. I'd offer to trade ........?

It will be interesting to see how it sounds to you. Do you have any measuring gear like a mic? This, by the way, is the "approved" ? method for drawing series crossovers. It looks like this one is at about 3KHz. I drew the coil as an iron core. Just take off the 2 parallel lines if it's air core. Were there any labels or anything on the other 2 woofers?

Kent, I think these may be DIY speakers. The neat-o crossover construction and the fact that it is a 1st order series crossover makes me think homemade. Usually the KEF/BBC way was to use 18db or least 12db parallel. It looks like it is set for about 3.5KHz which is about right but that wouldn't do much for the rising highs of the woofers. That input lug IS very British but I don't think it's a B110. I can do some more research to try and figure out what those drivers are but it really doesn't matter if they have to go anyway. Assuming that the coil is the right value, you probably could use those Dayton drivers. It would take some work to figure out what their tuning would be in that box. The other thing is the rubber surrounds on the vintage Brit drivers are stiffening up so the Fs and Qts are going up which totally ruins the enclosure tuning anyway. Chris

I actually spend most of my time with older British speakers so I have some experience with B110's and their ilk. Generally speaking those 5.25" drivers did have rather large magnets which is another reason I thought they were English. The Daytons might be fine but it depends. I'll be keen to see what the crossover looks like. Some of the BBC/KEF crossovers are very specific to the drivers used and will sound awful with anything else. Look up the LS3/5a crossover. Yikes!! They were that way because the Bextrene coned drivers had an uneven upper end. Properly adjusted they were incredibly natural with vocals which was a big deal at the BBC. Those tweeters are the big brother to the famous Audax 12X9 one of the earliest great 1" dome tweeters. Chris

Very odd. There's no stickers on the other 2 woofers? The dust caps look like Peerless or ELAC but the chassis' look like KEF B110 or Dalesford D30/110. The surrounds look like rubber. Are they? The DC130A-8 drivers might be OK but if the mystery woofer's response is anything like a B110 the crossovers might well need some modifications. Great tweeters!

A robust discussion of the Aperiodic topic if one cares about the nuts and bolts: https://www.diyaudio.com/forums/multi-way/115810-model-aperiodic-boxes.html A interesting application of it by a respected designer: http://www.troelsgravesen.dk/JBL_L100_08.htm

The schematic I uploaded above is the one for the 14 (slimline) because it has the "compensated" jack. The 15's are identical to 14B's but didn't have the network because you were only supposed to hook them up to a KLH console which had the equalization built-in. The network is basically a very broad mid-range notch or from a different point of view it boosts the treble and bass. The resistors act as part of the network AND bring the impedance back up to 8 ohms nominal. The "less is more" also applies to the mids in your 5's.

If you can, it's a good idea to thin out RoyC's surround sealant for the 12.5's. If this isn't possible, put on just enough to cover. Less is more. Do not put any on the dust cap.

Sorry for the upside down close up picture. No ideas on the different surrounds?

First the Family Portrait. The 2 on the left are the gauze type and the 2 on the right are the cloth type. The top right one is a Model 24 tweeter. And here is a closeup of the bottom 12.5s.

Here you go.

True, but my point was about what it is made out of rather than the color. The tweeter in the Model 24 and the 3" fullrange from a Model 8 have similar surrounds to my 12.5s out of the 11 portable. I've looked at a lot of pictures on Google and all the 12.5s appear to have the gauzy surround with black or clear goop. I would have thought someone else here had seen some like mine.

So I ended up getting an entire gallon of Toluene and thinned out some of Roy's goo. In a non-scientific way, I would say that the result was about half as thick. I have some totally beat up 11 portable speakers which are essentially unrestorable because of the case so I didn't feel bad about harvesting a driver to try the thinned goo on. It would appear that there is more than one variety of 12.5 which I hadn't realized. The ones out of the portable have a different surround from the ones in my 11w's. I haven't looked yet at any of my 14's. The material is cloth with a clearish sealant. The ones from the 11w are more like a gauze with a black sealant. The cloth ones also have a lower Fs. Any ideas?

In case anyone cares, the coil is 5mH and 1.8 ohms. I have a set of Fourteens, Fourteen B's and a set of Model 15 speakers which are Fourteen B's without the network. I pulled the network out of a Fourteen when I started the restoration. I also think the Fourteen is one of my favorite speakers. They're kind of like Bumblebees who shouldn't be able to fly. Fourteens shouldn't sound as good as they do.

Richard said he couldn't sell me his sealant and asked which drivers we were talking about. I sent him a even more detailed description of the 12.5s and the AD5060s and the fact that we have a most excellent sealant but I have concerns about using it on the little guys. I said since he is expert at putting sealant on cloth (ADS tweets and mids), I would appreciate any insights he might have. His response..... "I have done AR woofer surrounds in the past with cloth surround sealer. I think you should find the original coating to use on your drivers." Needless to say somewhat disappointing.

Inspired by the link Pete B suggested about tweeter renovation, I reached out to Richard So the ADS rebuild god. I am now in contact with him and will report his thoughts on the topic of light weight goop for mid-ranges and 12.5s. More to come.

I agree. I think the Lexel should be investigated, I don't think 17s should be the guinea pigs. I would say check out some thrift stores and find some no-name crap speakers to try it on. Of course if you don't have the gear to check the Fs before and after you could only go by ear. Not very scientific. Another low tech test might be to get a bit of Oxford cloth or even T-Shirt material and put some Lexel on it, let it set up and then see if how pliable it is. It should be close to the same as having none on it. Your 17s won't get much worse if you wait a bit and do tests first.

Thanks ra.ra. It kinda looks like Startex is a East Coast thing. I am in Washington State near Seattle. I can't find any quart cans just the gallon. I could, if necessary, use Xylene which I can get in quarts. Roy said it is OK to use but if I can I'd rather get the real thing. I'll keep looking.