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Salvaging an old cerwin vega sub.

1320 Views 19 Replies 7 Participants Last post by StrixNebulosa, Jun 17, 2021

StrixNebulosa

Discussion Starter · Jun 11, 2021

Hi all and good day to you. Never built of fussed with a speaker before so Im new at this. I have a Cerwin Vega LS 10 subwoofer that I'm exploring options with. It was never a great sub, but it currently has a lot of distortion that detracts from music and home theater. I suspect the driver has gone out to some degree. I'm looking to give the associated Cerwin Vega bookshelves and center channel speaker to my wife's sister as she has no sound system whatever currently and I have these hanging around. I would give this sub to her as part of the package, otherwise she wouldnt have a sub with the system. She has very little money and couldnt afford another one either as she's a single mom with five kids. So anyway' I'm considering replacing the driver on this subwoofer. I'm considering the Dayton Audio 10" HF 10 inch reference subwoofer driver or a cheaper 10 inch driver off of Amazon. The cheaper one is Goldwood sound GW-10pc-8 which is 200 w rms and 400 peak. The amp in the Cerwin Vega sub is 100 w RMS but says 200 w on the back. I assume that means peak. The Dayton Audio driver is rated 350 w. Would this amp have trouble driving the Dayton driver or even have trouble driving the goldwood? Would I risk damaging the amp or drivers? Would I get better sound out of the more expensive driver? What do you all think?

1 - 20 of 20 Posts

smcmillan2

· #2 · Jun 12, 2021

The only Cerwin Vega LS 10 I was remotely familiar with was not a subwoofer (and Google doesn't come up with one either). Have pics of the unit?

You're likely throwing good money after bad trying to retrofit an off-the-shelf driver into an existing cab, unless you've modeled in WinISD or the like.

Bigger question, does your sister-in-law need a subwoofer? As a single mother with 5 children I would guess not, has more pressing matters to attend to.

StrixNebulosa

Discussion Starter · #3 · Jun 12, 2021

Sorry its Lw 10 sub.

StrixNebulosa

Discussion Starter · #4 · Jun 12, 2021

Whether she needs a sub meh, who doesn't need a sub right? It will be a home theater/music system compsed of bookshelves and center. I think a sub would help.

StrixNebulosa

Discussion Starter · #5 · Jun 12, 2021

smcmillan2 said:
The only Cerwin Vega LS 10 I was remotely familiar with was not a subwoofer (and Google doesn't come up with one either). Have pics of the unit?

You're likely throwing good money after bad trying to retrofit an off-the-shelf driver into an existing cab, unless you've modeled in WinISD or the like.

Bigger question, does your sister-in-law need a subwoofer? As a single mother with 5 children I would guess not, has more pressing matters to attend to.

So would swapping a 10 inch driver with another 10" driver make enough difference to require modeling?

smcmillan2

· #6 · Jun 12, 2021

The Lw 10 cabinet does not look to be built well enough to experiment with, based on the pics I could find. It may very well be the biggest contributing factor in the distortion you're hearing and if so, no driver swap will solve that.

Again, pictures may help to determine what you may (or may not) be able to do with this cabinet, but my initial reaction is it's not worth putting money into.

Also note that you need to consider resistance when looking at drivers. Those you've listed are 8 and 4 ohm, do you know the resistance of the existing driver?

Reactions: 1

Vergiliusm

· #7 · Jun 12, 2021

I like your thinking and this is the DIY area, but for that application where you need something better than you got for a low price, you can get one of these for not much more than the Dayton 10" HF:

10 Based on the old Snell subs

SUB 550P | 500W, 10-inch powered subwoofer

PrimeTime

· #8 · Jun 12, 2021

First, you should try and determine if the woofer is damaged. Remove the grille (it is held on with a plastic plug/socket arrangement in four or five places, I think) and inspect the woofer. Does the surround appear to be intact? Is the surround deteriorated, or detached from the cone? If the surround is OK, place your hands on opposite sides of the cone and gently press inward. Does it feel like anything is rubbing when you push in?

If the surround is damaged or detached, you can get new surround refoam kits from Speaker Exchange. It is best to keep/repair the woofer, as most replacements will be inferior. If you are in or near a major city, there may be a repair shop that will fix it for you for a nominal charge.

If you decide to replace the woofer, you will need to remove it to measure the baffle cutout diameter so that a replacement driver will fit. IIRC, the woofer may be secured with capscrews that require an Allen-head hex wrench.

StrixNebulosa

Discussion Starter · #9 · Jun 12, 2021

Vergiliusm said:
I like your thinking and this is the DIY area, but for that application where you need something better than you got for a low price, you can get one of these for not much more than the Dayton 10" HF:

10 Based on the old Snell subs

SUB 550P | 500W, 10-inch powered subwoofer

That is a very good point.

StrixNebulosa

Discussion Starter · #10 · Jun 12, 2021

PrimeTime said:
First, you should try and determine if the woofer is damaged. Remove the grille (it is held on with a plastic plug/socket arrangement in four or five places, I think) and inspect the woofer. Does the surround appear to be intact? Is the surround deteriorated, or detached from the cone? If the surround is OK, place your hands on opposite sides of the cone and gently press inward. Does it feel like anything is rubbing when you push in?

If the surround is damaged or detached, you can get new surround refoam kits from Speaker Exchange. It is best to keep/repair the woofer, as most replacements will be inferior. If you are in or near a major city, there may be a repair shop that will fix it for you for a nominal charge.

If you decide to replace the woofer, you will need to remove it to measure the baffle cutout diameter so that a replacement driver will fit. IIRC, the woofer may be secured with capscrews that require an Allen-head hex wrench.

There is no damage to the foam surrounds. I think it may be under damped and as someone mentioned might be a flaw with the design of the box. It seems to ring alot. When I plug the port it seems to improve.

Vince_B

· #11 · Jun 12, 2021

StrixNebulosa said:
it currently has a lot of distortion that detracts from music and home theater. I suspect the driver has gone out to some degree.

If the foam is good, the woofer may be fine, and the amp not fine. You should probably try to determine which one really has a problem. If you have another woofer try it even if it won’t bolt in to the cabinet. Also I’d take the current one out and let it play free air and just inspect it. I’m assuming it used to sound better?

Chris Popovich

· #12 · Jun 12, 2021

There is "the right" and "the other" way to go about this. Let's use some pragmatism here considering the situation.

1: Find a way to make sure it's not the amp that's bad. Another speaker, whatever. If amp bad = game over, not worth replacing amp and speaker in old box, just buy new cheapie-cheep unless you have one kicking around.

2: Assuming amp is good, measure cutout in box for existing driver. They can vary and you prob don't want to enlarge the hole, and you for sure don't want to make it smaller.

3: Assuming amp is good and driver cutout in existing box is reasonable.... find a cheap replacement on partsexpress that fits, bolt 'er in, and never look back. It's a cheapy-cheep gift, not an engineered masterpiece. It'll be fine.

StrixNebulosa

Discussion Starter · #13 · Jun 12, 2021

Great advise everyone, this is why I came here. It works ok, its just rumbley. Is there a way to test the amp without another driver?

Vergiliusm

· #14 · Jun 12, 2021

StrixNebulosa said:
It seems to ring alot. When I plug the port it seems to improve.

StrixNebulosa said:
It works ok, its just rumbley

That sounds more like a room issue--energizing a mode near tune in probably the upper 20's, low 30's. I'd experiment with placement, and maybe even add some damping inside the cab.

StrixNebulosa

Discussion Starter · #15 · Jun 12, 2021

Its been in multiple places. Does the same thing. Perhaps its just a poor design not worth saving.

Chris Popovich

· #16 · Jun 12, 2021

Vergiliusm said:
That sounds more like a room issue--energizing a mode near tune in probably the upper 20's, low 30's. I'd experiment with placement, and maybe even add some damping inside the cab.

It's an old CV.... raise those numbers an octave lol.

Reactions: 1

PrimeTime

· #17 · Jun 16, 2021

StrixNebulosa said:
Its been in multiple places. Does the same thing. Perhaps its just a poor design not worth saving.

Check the xover setting, make sure it's not set below 80 Hz.

Yes, the old CVs were tuned around 37 Hz. Tons of output, though.

StrixNebulosa

Discussion Starter · #18 · Jun 16, 2021

The port in the back is huge. So is the box. When I plug the back with a toilet paper roll, it settles the extra ringing down a bit. I have the crossover point in the back set at 120 hz.

LastButNotLeast

· #19 · Jun 16, 2021

Do you think she's really going to care?
Ask her - you may be going through all this for nothing.
Michael

StrixNebulosa

Discussion Starter · #20 · Jun 17, 2021

She may not care initially as she will be happy to have music and home theater. I just know the sub would make a huge difference in the sound quality she hears based on my own experience. I got the sub, four LS-5 bookshelf speakers and a LS-6c center channel as a package used for about $200. I then changed the sub out for an inexpensive polk sub which improved things a lot. I have since upgraded the speakers to Polk signature S55, S15, and S30 and a cheap polk sub. Then I upgraded again to Polk Lsim 705, 704c and 703 bookshelves and added a svs sb12-nsd. I moved the Polk Signatures downstairs along with the cheap polk sub and now have these Cerwin Vegas sitting around. I think they would be an upgrade to what she has, which is nothing. But I might suggest that she might be better off without a sub than using this thing. I thought I might try just a driver replacement just to see if things improve. If I go with the Dayton driver and if it doesnt work, well then I could build a nice dyi sub for myself to replace the cheap polk sub in the basement. So either way Im not out much. Just exploring options. Originally, before we decided to give my wifes sister the Cerwin vega speakers, I toyed with the idea to use parts from the cewin vega sub for a build. Sounds like that might not work out very well.

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