Speakerlab 7 Restoration

[gdmoore28]

This has been a fun thread. I can remember back in the 1970s browsing the SpeakerLab catalogs and simply lusting over the Model 7s. All these years later I've still yet to see or hear a set first hand. I do remember one of the larger record stores in town used to have a pair of SpeakerLab speakers that had horns and a single woofer - can't remember the model number - but I loved the way they sounded.

GeeDeeEmm

 

[dc270]

This has been a fun thread. I can remember back in the 1970s browsing the SpeakerLab catalogs and simply lusting over the Model 7s. All these years later I've still yet to see or hear a set first hand. I do remember one of the larger record stores in town used to have a pair of SpeakerLab speakers that had horns and a single woofer - can't remember the model number - but I loved the way they sounded.

GeeDeeEmm

The Speakerlab 6 had the horn drivers as well, single woofer low end.
DC

 

[Ckafoweeth]

Hey Eric,

Thanks for the reply. It would be very interesting to come and hear what your 7's sound like. I have been really happy with mine.

Now that they are all together, I am having too much fun listening to them to take them back apart to fiddle with the crossovers. There is some work that I need to do in there though, so it will happen. It looks like one of the Zener diodes protecting one of the tweeters might be blown as it is very attenuated as compared to its partner. I am hoping that is all it is, anyway. The L-pads need some cleaning too.

What type of digital crossover are you looking at? The more I learn about these speakers, the more I think redesigning the crossover would be an interesting, worthwhile project. I am still in the learning phase of that one.

Which Emotiva are you using? I have heard nothing but good things about those amps. I am using a Denon, but I don't have much to compare with. (yet...)

Cheers!

 

[Ckafoweeth]

Glad you are liking your Sevens, Im still working on my 6's.

CKA, I was wanting to know, how it went when you dismantled the mid horn driver. I want to check the ferrofluid in mine . Really don't know if its there or not.
The T35 tweeters say ..do not take apart...so I am concerned I may screw up the hd700 mids, if I take the back off.
What did you do?

Thanks.

mcgarick,

This is a very late response, but I didn't see your last post until this last round of activity. The ferrofluid replacement in the mids was not too bad. It takes a bit of a gentle hand to put the two halves back together, but there were indexing points on the diaphragm side of the assembly that took over with the alignment once I got it close enough. Still a bit nerve wracking, but it all came through pretty well.

Like I said before, I did everything at once, and they came out sounding pretty good, so I don't know how much influence the ferrofluid replacement had on the final out come.

I hope your project went smoothly!
Cheers

 

[mcgarick]

Thanks, it did go smoothly. I cleaned out the ferrofluid which was very gummy...and did not replace it. I ended up changing the driver out to a larger Atlas driver used in their Corner horns AND also called a K55 by Klipsch.

 

[ericl]

I use an Emotiva UPA Gen 3

I will probably use a product from www.minidsp.com for the cross over.

As for your tweeter/zener diode issue, it could be the L-pad. What I would do is to via your computer as input to your audio system play a 7K Hz test tone (7K Hz will be above the 5K crossover point from mid to tweeter) while turning the L-pad knob - compare both speakers. You could also buy a SPL meter from radio shack/wherever to measure output level. FYI I have been listening to these for 45 years now & have always adjusted the L-pads so that they do not attenuate at all.

 

[ishwash]

The 10 woofer; if it was the ones with the numbers 7819 stamped on the back of the driver, is indeed wound backwards and the red mark is on the wrong terminal. It will be out of phase with the 12 if you hook it up normally. I know because mine are 7819's. I have a May 19, 1978, letter from Speakerlab stating this.

I'm in the process of rebuilding my 7's, replaced the caps (from Crites) and changed to the Crites tweeters, CT120, and midrange drivers, the Crites A-55G, kept the woofers because they were fine. There was no rubber gasket installed for the midrange drivers and they need that gasket so you can tighten and seal the driver to the horn, my drivers were lose. You can make a rubber gasket or buy one from Crites. I went to his digs last week outside of Russellville, AR. He's cool!

Refinishing the cabinets so have not listened to them yet. Glad the speakers have L-pads in their crossovers so I can turn the new tweeters and midrange drivers down a bit if necessary because the Crites replacements are significantly louder. The new A-55G midrange driver should be a considerable improvement over the old EV "siren" drivers. Both the mids and the tweeters are EV's. Never have found the EV model no. of the midrange horn though.

 

[Ckafoweeth]

Speakerlab used a bunch of drivers for the midrange on these. I think most of them were actually Atlas drivers. Did your midranges look like this:

 

[ishwash]

Speakerlab used a bunch of drivers for the midrange on these. I think most of them were actually Atlas drivers. Did your midranges look like this: View attachment 1125518

So sorry to post incorrectly. The midrange driver for my period of 7's (1978) is an ATLAS DRIVER. it does not look like the driver in your picture. In profile view mine is shaped sort of like a flying saucer and has a U-shaped steel strap of about 3/4" width going over the top of it. I went to see Crites knowing it was an Atlas and somehow I had a brain fart and lapsed back into thinking it was an EV after I left him. Crites even called it an Atlas "Siren" driver, and he said that may or may not be true. It is my understanding that the Super 7's of that era had a better midrange driver, and that it was Atlas also. Paul Johnston in Seattle who used to work for Speakerlab there in Seattle is attempting to get my Atlas midrange model number, if he does I will post it here, not that it's of any real consequence.

When I get my old cabinets coated, using black lacquer so I have to wait for 70 degree weather, and reassembled using the required two containers of clear silicone RTV...haha...I will post my feelings here on the upgrade to the Crites CT120 tweeters and the Crites A-55G midranges, but I anticipate success because I think the l-pads in my factory-preserved crossovers (preserved except for new capacitors) will still have the ability to mute them enough that they won't sound too harsh. If too harsh, I WILL install a bit of resistance in series with the new tweeters and midrange drivers to take them down a bit in volume.

But I will say this Mr. Ckafoweeth, if you decide you want to abandon your old Speakerlab 7's or Super 7's, whichever is the case, I will take them off your hands...grin...

 

[Ckafoweeth]

Good luck with the build. I am really curious to see what your black lacquered cabinets look like when you are finished. I would also recommend stuffing the cabinets. I did that last time I had mine open, and it made a big difference. The original fiberglass lining is no match for these woofers.

 

[ishwash]

Good luck with the build. I am really curious to see what your black lacquered cabinets look like when you are finished. I would also recommend stuffing the cabinets. I did that last time I had mine open, and it made a big difference. The original fiberglass lining is no match for these woofers.

Ok, will take that advise. Clear full...did you use fiberglass? You prob said further up the thread, I'll check.

I have not tried to lacquer finish anything...well, I guess spray painting an old Landcruiser once with lacquer counts. Should have waited until Spring or even Fall...there is so much humidity here in Arkansas at present and reading all the do's and dont's has me askeert.