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Discussion in 'Amps and Cabs [BG]' started by XsSpeed, Dec 9, 2020.
I am looking for a recommendation on where to send my (4) 15" Sunn speakers for repair. Thanks!
Any QUALIFIED speaker recone shop. The end results may not be the same as the original speakers however because the original factory soft parts are no longer available (and haven’t been for a couple decades).
If at all possible, find a local company. Shipping those speakers will be pretty expensive. A good reconer can build a kit from scratch that will be just a good or better than the original.
I just remember times when a good tech fixed a speaker just made and replaced the coil in the kitchen. No kit replacement need it. This kind of service seems to not be accessible nowadays...but thinks that times they used reversible glue, easy to attack with solvents, no hard epoxy,acrylics or whatever...Remember they used some sort of varnish and hardened the coil in the oven...they saved the cone and suspension and just replaced the coils. Hope you coil can be replaced without damage...
Not really. The problem with this is that you have to know exactly what the original components are in order to duplicate them. Thing like spring rate of both suspension components, voice coil, cone mass, moving mass, cone shape, pulp thickness and stiffness, etc. Everything will be a guess, and almost guaranteed to be significantly different than the original speaker (even if it looks "close"). I hear this all the time, yet when the results are measured and the TS parameters are extracted, the results are always very different.
Naah, again this is old wives tales. Never in the history of recent (as in the last 40-50 years) bass guitar speakers has this been true. Especially on products with tighter tolerances, like most products in the last 50 years. I've been a recone guy (JBL certified in 1978) with a lot of experience and it's just not true.
Maybe in the 1920's -1940's, but none of these speakers would be suitable for bass guitar, not even close.
You have to believe it. It happened in '80. We recoiled a lot of 15"/50w RFT east-German made speakers as I said. I growed into a communist country. We didn't afford to throw nothing. We had some good skilled craftmans which made a life with that. I remember they even had some press to make aluminium dust caps by size from sheets...Nothing very expensive, made with passion not time means money. It was a current repair also for some Electrovoice and Goodmans replicas , many used in that era.
It doesn't really work this way.
Likewise the OP is reconing JBL speakers.
Back then simply the most expensive highest quality speaker available.
Multiple patents for these drivers. They use extremely tight gap tolerances. That many or even most manufactures don't even use.
The Efficiency and tone of these speakers is highly regarded and demand extremely high prices.
Not something you do in the kitchen lol.
You don't wedge in a new coil.
The cone spider and coil gets replaced.
I'm assuming we are talking JBL drivers?
Or is this the later special design Eminence Magna speakers.
The cost involved to recone magnas is not likely worth it. As far as JBLs a much different story.
I can't see a diy rewind when the coil is edge wound square cross section aluminum wire.
Surely it not works for any speaker
It's not that it doesn't work.
It just yields very very poor results.
And would be close to impossible for the speakers mentioned.
As with any information thread or forum
If this thread is used for future reference.
It's better to have speculation or misinformation addressed. So it doesn't cause misunderstanding or misleading information for future reference or users interested In more specific information. In this case and all cases. Information that is not off topic from the original post.
Unfortunately misinformation leads to off topic discussion
Can't you just buy new speakers? Itd probably be faster, cheaper, and out performing.
If it is JBL speakers
They are highly regarded and carry very high value. Nothing will sound the same. And Sunn collectors usually demand original JBLs.
He mentioned 4 15" speakers. So if we are talking about a later 415M or 415B
The later Magna Eminence speakers are yes easily replaced and outperformed or matched by modern Eminence replacement.
Even Eminence has no information on older metalworks found in later Sunns. It goes as far as knowing the EIA code. And that is about it
True, there are a lot of variables to contend with. I did say a good reconer. Assuming the four speakers do need to be reconed, chances are the result will be a different performing speaker from the original. A good shop will know what to do to make it right.
I looked and I don't have any information on the Sunn drivers. I'm assuming they are the non-JBL drivers, the JBL drivers can be reconed, though they may require aftermarket parts. Note that there are some good aftermarket parts and some awful parts, a pro recone shop will know which are the good parts as they dont like to re-do their work due to bad parts.
Until the OP replies we don't know if it's a JBL or Magna.
Far as finding information the 15" Magna 158 Special design was either made by Eminence or CTS. You can't really tell unless you remove the Sunn Sticker.
The CTS or Eminence look exactly the same.
Same basket, Same Square Magnet
Eminence would have 67 EIA code 137 for CTS
Both can be reconed with generic kits.
The coils and spiders are nothing special.
Likewise gap tolerances are nothing like a JBL
As far as JBL recone company's
believe Orange County Speakers was pretty notorious. But closed shop. The main engineer started his own company. Probably seen more JBLs than any one. Assume a internet search might find him.
I know Dr Tube is another supposed JBL guy
Orange County Speaker Repair is now GLS Audio
The family that owned OCS sold the recone business to an employee(s) to concentrate on the accessory business.
I went through the JBL recone class in 1978, same time as one of the family members.
Dates back to 2002. For OCS
Everything changed after those stupid planes hit.
All my stocks went to garbage
And everyone seemed to be selling.
BAM magazine had disappeared
The Bammies disappeared.
Any real artist or club featured in BAM disappeared
Fender Frontline stopped artist interviews
List goes on and on.
Anyways, hopefully he's still around
Probably seen more JBLs than anyone.
So basically we put these speakers in the Sunn cab and they vibrate/rattle too much. Yesterday I put 2 small ports in the back and mattress topper insulation inside and it helped marginally. We wanted the original sound back. I’m pretty sure they are the magnas but I need to get them from the singers house to see.
Random thoughts, in no particular order:
What exactly is vibrating/rattling? If it's not the speakers themselves, I suspect the rattling would continue with the newly reconed drivers.
IMHO, it wouldn't be worth the cost to recone the drivers if they're the Magnas. And if they were the JBLs, you'd probably already know it -- the aluminum dust covers would show through the grill cloth. Plus the additional weight they add would be substantial when multiplied by four drivers.
i can't help noticing that you used 4-ohm replacement drivers...I hope they were hooked up series-parallel; not many amps will survive pushing a 1-ohm load.
Based on what theory?
Anyway...I'd see if I could figure out what the vibrating/rattling really is...it's possible that the drivers you have are not the issue. Then there's a problem with the math of a 4-driver box -- four times anything starts to add up to substantial money pretty quickly.