Velo rebuild project

[j_garcia]

Not a new builder. Have built and/or rebuilt a number of subs and speakers and assembled kit crossovers from GR. I used to be an electronics assembler, so I know my way around a soldering iron Based on what Velodyne and TLS said, I will try to take it apart this weekend. Then I will also have an idea of what the internal volume really is as well.

 

[j_garcia]

Pulled this thing apart this weekend and nothing on the amp looks damaged. No leaking caps, no heat damage on any components. Will a servo driver work without a servo amp connect? I patched my sub line over to an external amp and then to the driver still in the cabinet and got a little bit of sound but a lot of distortion. Unless it won't work at all without the servo portion managing the driver, it sounds like the driver is toast; Sounds similar to other drivers I've replaced that had fried VCs.

 

[TLS Guy]

Pulled this thing apart this weekend and nothing on the amp looks damaged. No leaking caps, no heat damage on any components. Will a servo driver work without a servo amp connect? I patched my sub line over to an external amp and then to the driver still in the cabinet and got a little bit of sound but a lot of distortion. Unless it won't work at all without the servo portion managing the driver, it sounds like the driver is toast; Sounds similar to other drivers I've replaced that had fried VCs.

The driver should work without the servo, but with significant loss of base extension.

Can you feel gap rub, and what happens when you do the battery test?

 

[GranteedEV]

The problem is that driver sealed has a high F3 and little room for Eq as xmax is only 14 mm. So you have a choice of high F3 or limited spl.

Your best solution is a new 10" woofer/ABR combo from SEAS. This unit has a an xmax of 28 mm and is pretty sensitive.

That's peak to peak. That's only 14mm xmax one way...which is... identical to the dayton.

 

[j_garcia]

The driver should work without the servo, but with significant loss of base extension.

Can you feel gap rub, and what happens when you do the battery test?

No, doesn't sound like it when I just push on the cone (don't feel any rubbing or hear anything), but when powered up the output is low and scratchy. Didn't do a battery test because after I got that muffled, scratchy sound, I just figured the driver was toast.

Won't be looking for a ton of SPL out of this thing since I already have the Empire and it will most likely go in the second system anyway. I'd be looking for good performance higher up, so adequate low to mid 20s output and clean as opposed to subsonics.

 

[TLS Guy]

No, doesn't sound like it when I just push on the cone (don't feel any rubbing or hear anything), but when powered up the output is low and scratchy. Didn't do a battery test because after I got that muffled, scratchy sound, I just figured the driver was toast.

Won't be looking for a ton of SPL out of this thing since I already have the Empire and it will most likely go in the second system anyway. I'd be looking for good performance higher up, so adequate low to mid 20s output and clean as opposed to subsonics.

So there is no gap rub.

Do the battery test and measure the DC resistance of the voice coil. If those tests are fine then the driver is OK.

Also inspect the driver also and push the cone up, to make quite sure the cone has not become detached from the voice coil.

If the DC resistance is OK, there is no gap rub, no cone/VC separations and good throw on the battery test, then the driver is fine.

 

[j_garcia]

Don't have a DVM on hand, so will have to locate one.

 

[annunaki]

Thanks for reminding me that project was done over 7 yrars ago now.

The 12W7 and 12W7-3 are one in the same. The new 12W7 AE is in all reality the same driver in different clothes. At least the T/S parameters indicate as much.

The only issue I see with a W7 in that enclusure is inadequate bracing and mounting hole diameter.

you could try to snag JL 12W7 of ebay

It would work very well in 2ft3 sealed box and would kill any commercial built $500 sub... Only issue is you would need [strike]a 1.21 Gigawatts[/strike] 1000 watts of continuous power, like announaki built 7 years ago:
http://forums.audioholics.com/forums/diy-corner-tips-techniques/15445-beast-its-lair.html


I don't know if 12W7-3 is similar to 12W7, but there are few more for sale:
1 JL Audio JL12W7-3 1-Way 12" Car Subwoofer (699440921121) | eBay
JL Audio JL12W7-3 1-Way 12" Car Subwoofer (699440921121) | eBay

 

[j_garcia]

There's basically no bracing in there at all. There is a little inset where the amp used to go, keeping it separate from the air space. Had a late meeting last night, so basically didn't get to anything else.

 

[j_garcia]

Battery tested and driver moves fine no noises. Must be the amp then?

 

[TLS Guy]

Battery tested and driver moves fine no noises. Must be the amp then?

You are correct and it usually is the amp.

 

[BoredSysAdmin]

Velo responded and said there isn't another driver that will work with that amp, so pulling both. They did send me a schematic for the amp.

Now that confirmed the driver is fine, maybe it's to try to repair the amp - you already have the schematic or spend a hundred or two for someone to repair it for you.

This book should give you decent guide on how to do it yourself:
How to Diagnose and Fix Everything Electronic

 

[j_garcia]

I used to be an assembler, so I do know how to repair electronics. It is the tracking down the problem that gets hairy. This is a mulch-tiered amp, and looking at it, there are no obvious heat marks, caps don't appear to be leaking, basically it looks OK without circuit checking.

There's a guy in town who fixes older gear but a few hundred to repair it is getting up there.