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Speakerlab S7s Rebuild and Modding (Ribbon Tweeter Model)

I forgot to mention that another revelation from using xsim is finally conceptualizing what is going on with the mids. I had noticed that other 3-way speakers have 4 coils in the crossovers, and had struggled in the past to understand how the crossover in my speakers was working with only 3 coils in them. Now the coin has finally dropped. Duh. The mids are running full range above the 350hz crossover point. Sometimes the simpelest concepts seem to take a long time to filter through my head.

Cheers,
James
 
Sometime after I bought my mids they went out of production due to lack of demand. That would leave me starting all over again if for some reason I had a problem with the WF160WA-01's. And would complicate things for a friend of mine that's thinking about diy building a pair of S7s as he wouldn't be able to directly use all the info that I've built up.

Since then I had found 4 substitute possabilities. 3 from SB Acoustics, the 6in SB17NAC35-4, the 6in SB17NRXC35-4 and the 6in SATORI-MW16P-4. They would all fit within the step baffle, although the first 2 would be a squeeze with their 171mm frame od. The last that I found that looked interesting is the Scan-Speak 18W-4434G00 but it would require routing out the step baffle because of it's 179mm frame od. But that wouldn't be a problem for my friend starting from scratch.

That's the way things stood until yesterday when I noticed that Wavcor is producing something in their automobile lineup called the WF166TU01 & WF166TU02. They look to be an exact match of the WF160WA-01 & WF160WA-02, the only difference that I can see is that they have a heavy cast frame. They are more expensive than the WF160s by about €15 each, which seems a small price to pay for a nice cast frame.

They look interesting enough that I'm considering buying a pair of the WF166TU02 (normal magnet as opposed to the neodymium magnet 01's). They are only €80 apiece so not such a heavy investment as the neodymium magnet models. I would then save the WF160s for a long term project of making a new HT center with those 2 speakers in series and a single MHT-12 ribbon between them.

Anyway, other than that today I bought some 18mm beach butcher-block type shelving boards as raw material to use for my crossover enclosures. I still haven't completely conceptualized how the enclosures will look but will start playing with layouts when my parts finally get here (still mostly on back order). I also haven't found dual post binding blocks that I like, I might end up just buying some posts and work them into the design that way.

Cheers,
James

http://www.wavecor.com/html/wf166tu01.html
http://www.wavecor.com/html/wf166tu02.html
 
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Press nuts. First I looked for them at the websites where I've been buying speaker parts. €0.62 each for M4. And I need 44 if I want to do this right. So that would be over €28 with shipping for a handfull of nuts. NUTS to that.

Yesterday when I was at the local building supply store they had them packed 8 pieces for €2.30. Hey, that's only about €0.29 each, so €12.65 total. Somewhat better but still stupid expensive. So last night I found a box of 100 through amazon for €2.19. That's more like it, and 50 SS M4x40mm allen head cap screws for another €6. On the way. Now I just need to find some nylon washers and I'm set.

Cheers,
James
 
Today I finally folowed through on scanning the S7 owners manual and assembly instructions. The pdf files are 2.2 and 1.3 mb and so are too large to attach here. Anyone that wants a copy can PM me and I'll provide them, or the raw page scan jpeg's for that matter.

Speakerlab Super Seven Owners Manual 01.jpg

Cheers,
James
 
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nerdorama said:
Maybe AK would like a copy for the manuals database.
John
Click to expand...

Hi John, I thought about that but the regs in the database forum state not to upload files unless there is a request. :D

Cheers,
James

edit: Well, I'm a bit confused, in "How this forum works" I see "Please don't just start uploading at random. Only upload what someone asks for", but in "Please help the AK Database!" it seems to indicate that it's ok to send files to ak.pdfs_at_gmail.com, so I stuck my neck out and sent the 2 files there. What's a poor dumb Bratwurst to do? I hope that I don't land in the frying pan.
 
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Nice work, James.

I want to bring a comment made in the other thread (Yamaha A-500) on those "little" Grundig's you showed in that thread, to share what I've found recently: a pair of Magnat's. These were built around 1989, IIRC...

Your Speakerlab S7s' are quite interesting. I have a similar project in mind and will see this thread from beginning. Do you still have the Grundig's?

Bratwurst7s said:
...

Originally I was bidding on a pair of Canton Karat 20s but they went way out of my budget very quickly. So I settled on the Grundigs which sound pretty respectable for their age and the low price that I got them for. And they are in very good condition.

Cheers,
James
Click to expand...

Some pics of the Magnat's... (a have another pair, btw).

29wwho5.jpg


eivbtj.jpg


2ahsj0w.jpg
 
Karl vd Berg said:
Nice work, James.

I want to bring a comment made in the other thread (Yamaha A-500) on those "little" Grundig's you showed in that thread, to share what I've found recently: a pair of Magnat's. These were built around 1989, IIRC...

Your Speakerlab S7s' are quite interesting. I have a similar project in mind and will see this thread from beginning. Do you still have the Grundig's?
Click to expand...

Hi Karl! Nice to see you here. Very nice speakers. I like Magnat's a lot and for some strange reason I see a lot of them here in Munich. :D Yours look very similar to a pair that my brother-in-law has, also All-Ribbon series from ca '85, but I can't remember exactly which model. Very nice sounding speakers.

The HiFi Box 650s went with the A-500+T-500 to a friend at work as a Christmas present. I've ordered new caps for them along with the last parts order for my 7s and am still waiting for them, just about the whole order went back order and it looks like it will be a couple of weeks before that stuff ships. They are a very nice clean sounding set of speakers and pair well with the Yamaha.

Progress report:
The M4 press nuts I ordered for securing my drivers arrived today, and the screws shipped, should be here tomorow.

Cheers,
James
 
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My crossover parts have shipped from Europe-Audio. And I realized that I haven't stated what I actually bought.

When using Xsim I first made a layout trying to simulate the original speaker as well as I could with the info at hand (layout 1). Then I made a second layout with the original crossover components and my current drivers, with zma files generated from wt2 to use as references (layout 2). Lastly I built a 3rd layout with my current drivers and 2nd order curcuit blocks with 350/3800 crossover points and saved that as reference (3a). Then I modified that 3rd layout with actual components that I could find giving values as close as possable to what the 3a layout showed, and played around with different coil wire dia/dcr values based on what was available.

What the simulation showed was that trying to lower the dcr of the coils created large peaks at the crossover points. So in the end I chose coils with dcr's very close to the originals. The parts list is as follows... (all components are Jantzen)

Tweeter: Single 5.1µf CrossCaps (replacing the 2x 2µF poly caps) and 0.33mH_0.8mm_0.39ohm air core coils (replacing 0.31_0.45ohm).

Midrange: 22µF+56µF CrossCaps = 78µF (replacing 33µF+47µF = 80µF elcos) and 2.5mH_1.0mm_0.88ohm air core coils (replacing 2.6mH_1.0ohm). Also new 22µF Crosscaps for the zobels.

Woofers: 56µF CrossCaps (replaces 22µF+33µF = 55µF elcos) and 3.58mH_1.2mm_0.82ohm air core coils (replaces 3.4mH_0.9ohm iron core). Again, CrossCaps replace elcos in the zobels, with wt2 showing me that I needed 64.2µF as opposed to 66µF.

The differences aren't enormous and I don't flatter myself by thinking that I've made perfect choices but it's a starting point and it came down to just making a decission and moving forward with the understanding that I will likely need to tune things later.

Concerning matching the spl of the drivers I will be first building the crossovers with no padding but plannning for space for resistors after measuring with REW. I already have a sortment of MOX resistors to use for that.

When I have the boxes apart again for this last step I'll install the press nuts for the woofers and tweeters, but not the mids at this point because the Wavecor WF166TU02 mids are round and have a different hole pattern, and at this point I'd still like to buy a pair in a few months to try out. I notice that Wavecor states that they can be crossed at 3.5khz as compared to 3khz for the WF160WA-01 even though every other spec for the driver is the same. I wonder if the cast frames contribute to less cone breakup at the crossover point?

So thats the stand of things at this point.

Cheers,
James
 
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So I've been waiting for my parts. In spite of what Europe Audio stated when I checked my account the order didn't actually ship until Tuesday the 24th. And when I checked the tracking number today GLS tells me that the order is sitting in their wharehouse because the package wasn't addressed correctly.

I checked my account info and I know that my address there is correct, and my last order from them managed to find my door, so I have to guess that they screwed up. I just sent them an email asking them to find out what is happening, I suppose that I won't hear anything before Monday.

Cheers,
James
 
My order finally got here today after a good bit of frustration.

http://www.audiokarma.org/forums/showthread.php?t=646215

A quick check showed that everything is there and in good contition. In the next few days I'll do a layout on one of the boards that I bought and make a final plan what size to make the crossover enclosure. I'd like to get the wood cut in the next week. The last week of this month I'm taking a week off to put this together.

I will be mounting the crossover on 4mm plywood and am planning on attaching each crossover section (low, mid, high) on a seperate piece and then attaching the sub boards inside the box. I'll make it all large enough to have extra space in case I wanted to get exotic later and switch to Linkwitz-Reilly 4th order.

I'll run each section to central binding posts. I realize that that will add a small amount of extra resistance in theory but since I plan on using a heaver guage of wire than Speakerlab used I'm hoping that any difference will be negligable. Mounting each section seperately will give me the flexability to make mods without having to remove the whole thing, and I would also be able to pre-build a modded section and swap it out with little effort.

That's where my thinking is going at this point. We'll see if I can make that happen.

DSC01137.jpg

Cheers,
James
 
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Woo-Hoo! The next step! :thmbsp:

Thanks for keeping us up to speed on your progression on the S7s.
 
Spalls said:
Woo-Hoo! The next step! :thmbsp:

Thanks for keeping us up to speed on your progression on the S7s.
Click to expand...

Happy to be of service. I played around a little bit today and am tenetively planning on outside dimensions of 300mm wide, 500mm deep and 100mm thick. I talked to our carpenter at work about cutting everything sometime in the next week and he is good to go with that. I just need to get to sketching some plans now.

Cheers,
James
 
Today the carpenter helped me out and cut the crossover enclosure wood on his huge precision table saw. The outside dimensions are 300mm wide, 500mm length and 100 deep. That leaves 264x400x82mm usable space in the main area. The closed area on top will fit over the binding post cutout on the back side of the speaker cab and will be sealed. There is a small 100x120mm board to mount the binding posts in the main area not shown in the pics. Thats still at work and will be home tomorrow.

The pieces are just sitting together at the moment. The next step will be getting out the dowel drill jig and installing dowels before glueing it all together. I don't have a back cover yet but plan on using a thin perforated fibre board screwed on the back, something that will allow some convection air circulation.

DSC01158.jpg DSC01161.jpg DSC01159.jpg

Cheers,
James
 
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Yesterday and today I got the first box drilled, doweled, glued and clamped. It's sitting now drying till morning. The base plate pic is decieving. In the end there were 13 dowels installed to hold the base to the frame walls.

The frame boards for the second box are partly drilled for dowels. Tomorrow I'll drill the rest of the holes and glue the frame together, by Monday evening it should be glued to it's base.

I can't explain why I used beach hardwood for these simple boxes. It's not like they will be under a lot of stress. Pine or fir would have been just fine and weigh a lot less. I just liked the look of the beach I guess, and this gives me some practice working with hardwood if I ever decide to build some new center/surround speakers using this material.

DSC01162.jpg DSC01165.jpg DSC01166.jpg DSC01170.jpg DSC01179.jpg

Cheers,
James
 
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