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DQ-1W bad juju

Assembly time...

These images are taken during assembly. I allowed the glue to cure overnight. I really didn't want to take any chances of the pole shifting during cure time. Seems to be holding strong.

First shows the assembled pieces. In the video, due to angle and sunlight, the gap doesn't look even. I tried to get a better image. The one posted shows that the alignment is close to dead on. I say close because I don't have a non ferrous measuring device to confirm it. Needless to say there is positively NO rubbing with the assembled system.

One image shows the new and old VC before assembly. Then the spider. The second image with the spider is actually showing the needle I had to use to thread the new lead thru the rubber bushings. The leads are too soft, even tinned. Last is the cone, but VC not yet wired to the leads. I'm completing assembly tomorrow and will post additional images and listening tests.

Turning out better than anticipated, and I was able to reuse the cone and surround.
 

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Fab work there! Nice repair and reconstruction.

The original glue held up for almost 35 years but like anything, it isn't forever. I think today they are using some forms of high powered cyanoacrylics for gluing magnet and pole piece assemblies but surely there are others depending on the qualities the OEM is looking for in the adhesive.
 
mech986 said:
Fab work there! Nice repair and reconstruction.

The original glue held up for almost 35 years but like anything, it isn't forever. I think today they are using some forms of high powered cyanoacrylics for gluing magnet and pole piece assemblies but surely there are others depending on the qualities the OEM is looking for in the adhesive.
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I've definitely come to respect the manufacturers who bolt/screw the magnet assemblies together.

I've got it hooked up to my Luxman RS1050 receiver and I don't believe it has sufficient power to get much out of this sub, not to mention the DQ Crossover doesn't appear to be helping much.
 
run it direct. That speaker doesn't care about some high frequencies. good for a test and all.
 
Blue Shadow said:
Just picking it up is quite a feat. That is a big sub and at 65 pounds it is no lightweight.

Nice repair. I know who I'm going to PM when my sub has a loosened magnet.
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LOL. I swear I've had some speakers sitting around for some time just because I just didn't want to deal with them. In the end, like this one, I was glad I did. Main thing, sometimes, is thinking outside the box.

Sure, contact me, no worries.
 
Copa,

Sorry to resurrect an old thread, but I recently bought a nice set of the Rogers L35B (huge cabinets BTW) and found that instead of rubbing, the coil was completely bound up-- much as you described in this set you worked on last year. This thread has been incredibly helpful in helping understand the construction of the actual SEAS driver unit.
I found a replacement yesterday that I'll pick up next week in the OC, but I want to comment on the structure I'd found as I dis-assembled this one. The adhesive on mine, like the one you worked on, had degraded to the point of failure.

The magnet is definitely bonded and that material would appear to have "aging" issues after decades. But, what I found once I pulling the magnet for a better look at the Top Plate and its connection to the basket puzzled me. The top plate, which appears to be still affixed to the original location on the basket, is BADLY mis-aligned-- it's clearly offset by 200 mils or so. The marks in the adhesive residue, which had held the magnet in place, indicate that the factory must have corrected for the top plate's position once the magnet was adhered into place-- to center the pole piece.

I just wanted to register some disappointment (one of your comments early in your re-build noted this) that, for such a nice set of materials in the driver, it's ODD that they didn't use any kind of indexing holes/pins in the assembly to ensure precise alignment. The holes are actually there in the magnet assembly, but it looks like they didn't use the mating pins/bores in the plate-and-basket when they tooled it.... using "procedures" at the factory to line it all (sorta) up.

The failure rate in this unit would have been much lower, after the adhesive started to degrade, had they built some DFM (Design for Manufacturability) into the assembly-- a cost decision I suppose. Anyway, my high regard for SEAS probably took a hit upon seeing how this one was put together.

The other L35B unit sounds epic good, when used with my B&W 805S, so I'm looking forward to getting its brother going with a replacement driver.
 
Great thread on magnet structure repair. My only comment is that of the importance of keeping the magnetic gap between the magnet and the pole pieces as tight as possible to keep the magnetic field strong; a gap from too much adhesive will increase the magnetic reluctance (the analog to resistance). I wonder of the mfgrs polish the mating surfaces?
 
Freds.Bands said:
Great thread on magnet structure repair. My only comment is that of the importance of keeping the magnetic gap between the magnet and the pole pieces as tight as possible to keep the magnetic field strong; a gap from too much adhesive will increase the magnetic reluctance (the analog to resistance). I wonder of the mfgrs polish the mating surfaces?
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Looking at the surfaces I believe they are, to some degree. I did in fact spend a bit of time just cleaning surfaces to ensure a good transfer of energy. The magnet is so bloody strong that I'm sure minimal adhesive was left between the mating surfaces.

Appreciate the input. Will help others as well.
 
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