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Speakerlab S7s Rebuild and Modding (Ribbon Tweeter Model)

Good idea. I've seen the website for The Loudspeaker Store and it looks like they know what they are doing. I wrote Speakerlab last week seeking info regarding the M654P & W1058P, have had no answer. Perhaps I'll ask Paul and see what happens. I won't blame him if he doesn't spend a lot of time on it. The truth is that I'm 8500 kilometers away from there, and realisticly will probably never spend a cent there. It's been 12+ years since I've been in Kent, and most likely never will be again. But I'll write and ask. Thanks scorwin, any info will be helpful, 'cause I can't find anything regarding the M654P, only a few stats from the Speakerlab site from old catalogs regarding the M658.

Cheers
 
Hi scorwin. I just sent a post to The Loudspeaker Store asking (begging) for help. Ill post any info that might be forthcoming.
 
Well, My post to The Loudspeaker Store just bounced. I tried every email address listed at their site without luck. Well, I'm on vacation and have flatrate telephone to the States. I'll try calling them tomorrow.
 
Super. Thanks. I just sent a post to him. I'll see what happens tomorrow, it's time for bed now for an old guy like me.
 
Thanks scorwin! Paul Johnston at The Loudspeaker Store came through like a champ.

First he sent me a jpg with the specs from a M654P that he tested while it was there for repair, and was nice enough to give me permission to post it here. He also let me know that they will be producing a new replacement for the M654P in the near future. And he's helping me find info on the W1058P woofers that I bought from Speakerlab.

M654PF TS and impedance plot.jpg

All in all very helpful.

Today I cut/enlarged the back panel opening on my cabinets for new binding posts, and cut some hardwood braces for the front baffle. Later I went and bought some stainless steel screws for mounting that stuff. And I talked to JH Elektronic where my W1208R's are getting repaired, they should be on their way home early next week. All in all a very good day.

Cheers
 
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Hi wweigle,

Thanks, I've seen that page also while searching fo info at the start of this project. But that crossover is for the earlier 7 with the horn tweeter and midrange.
 
Hi scorwin, sorry, I've never seen a nestrovic crossover. Would like to someday just out of interest.

Also, I have a correction to make. In a post that Paul sent me yesterday he mentioned the Delta-1 Hybrid Type-5 and that struck a chord. I remembered then that that was what my AF buddy had rather than the S50. It was always such a difficult mouthfull to repeat.

I didn't get much done today, just installed the front brace in 1 cab. For anyone that uses hardwood for a brace, you might want to drill a little larger pilot holes than I did and drag the screws across a bar of hard soap before screwing them in. That way you won't twist off the head of a screw just before it's supposed to seat. I remembered that trick on the second screw. :-( It would have been much better for my pride if I had remembered what my dad said a little earlier. My fun meter went straight to Off Scale Low. In the end I was able to correct that mistake, but then it was time for a beer.
 
Oh. Well. Last week I couldn't even spell nestorovic, and now I have one! :-) Thanks for the link. I dl'd the patents for reading later, but I probably won't understand very much. I'm not planning to modify the design, just duplicate it with improved components. (I'd probably just produce a 3 headed 1 eyed monster if I tried to start madding it) But after reading some of what Paul has told me I'm lowering my parts list to something a bit more reasonably priced. I tend to get carried away sometimes.
 
The Speakerlab 7's are not Nestorovic systems. They simply use two differently sized woofers wired in parallel with a 12dB per octave low pass. SL7sFan, you posted your crossover earlier in this thread and it's as I describe with the addition of a zobel (series R & C) to flatten the impedance curve.

The Nestorovic crossover uses a large value series cap on the larger woofer. The woofers, in addition, have VERY large magnets with low Q. The patents are online.

I posted some adventures with my S30's and the schematic here:
http://www.audiokarma.org/forums/showthread.php?t=148435&highlight=speakerlab

Have fun,
John
 
Thanks to everyone for all the help and comments, this is a great place to be.

GuyK - Thanks, I hadn't seen that thread yet. I bookmarked it and am reading through it.

scorewin and nerdorama - Thanks, I thought that might be a zobel circut on the woofs but wasn't sure, I'm a newby to this.

Yesterday I got the billl for the work on my W1208R's. Turned out to be less than I thought, about €110. I was expecting €20 more. I'll get that paid tomorrow and the woofers should be home this week. I stuck my head into the cabs and looked around carefully. All of the seems have a nice layer of glue bead squeezed out from the assembly, so I'm going to skip using silicone to seal them, except a small bead around the binding post blocks to supplement the foam gaskets that they have. If I'm not too lazy tomorrow I hope to get the cabinets to the point of being ready to start sanding.

nerdorama - Is that a DC3 cockpit in your avitar? nice pic. And yes, I AM having fun!
 
SL7sFan said:
nerdorama - Is that a DC3 cockpit in your avitar? nice pic. And yes, I AM having fun!
Click to expand...

B-17. I took it while having a tour in one at the Museum of Flight in Seattle. They had visiting bombers (B-17, B-24 and B25) and for a fee you tour all of them. It was great fun.

John
 
Nice. For some reason I've always loved the B-25. That's one place I would have liked to have seen but never did. Dumb, but sometimes a person doesn't take the time to look at something that's really just a short distance away.

Next weekend I'm taking a road trip with a couple of friends up to Sinsheim Auto & Technik Museum and Technikmuseum Speyer. They are only about 4 hours north of here, oughta be a fun weekend.

http://en.wikipedia.org/wiki/Sinsheim_Auto_&_Technik_Museum
http://en.wikipedia.org/wiki/Technikmuseum_Speyer

In the last year I was in the AF I got to help (a little) prepare a F-106 and a C-47 for the (then) new air museum at McChord AFB. Was a lot of fun.
 
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