Depth Repair Project

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JasonR

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I picked up a Martin Logan Depth subwoofer locally in pretty bad shape. It was improperly packed by the previous seller and just about destroyed by UPS, but the cabinet is structurally sound, and all but one woofer escaped damage.

I figured I'd document the repair process since I haven't seen anthing like this on the ML Owners forums yet.

Let's start with some 'before' photos. Almost every corner of the cabinet was damaged, some quite severely. And you can see one woofer is certainly shot.
 

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JasonR

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I spent the better part of the day cutting away the damaged areas, filling the voids with Bondo, and sanding. I picked up a Black & Decker "Mouse" sander... a little $40 unit that really made this job a LOT easier than doing it by hand.

The 'rear' of of the top was difficult because of the complex angles, and the 'front' wasn't too simple. But Bondo, sanding and time is just about all that seems to be needed.

The below views are all with the cabinet upside-down... waiting for an area of Bondo to dry. More photos to come shortly...
 

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JasonR

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The cabinet is nearly ready for paint. Now the question is, what kind of paint should I use? Flat black spray paint would do the trick, but I wonder if I should take this opportunity to do something a little different. Any ideas come to mind?

Thanks!

- Jason
 

C.A.P

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Ok what I don't get is the UPS man droping it and saying OH SH!T > Then he reports it damaged. That thing looked like it went through a damage demonstration.

This paint I have been using with great success. I just re painted my Quest cabinets and it looks great. and is tough as nails. I have a matching sub Im building that is finished in that paint too. I used the dark charcoal


http://www.rustoleum.com/CBGProduct.asp?pid=31
 

JasonR

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Thanks for the paint recommendation. I used the Seafoam Green textured Rustoleum on a project years ago, and come to think of it, it did create a fairly durable finish. I'll definitely consider it. Plus, it won't 'show' as many imperfections that may happen when I spray it and let it dry outside.

As for the damage... basically, the previous owner purchased two used Depth subwoofers, I believe from different sellers. This one arrived badly damaged due to improper packing on the seller's part. UPS picked up the damaged Depth to evaluate it, and sent it back to the seller with even further cosmetic damage. They denied the claim based on the box and/or packing material not being sufficient to protect the item. (I don't have much detail since I wasn't party to that.) The seller ended up being stuck with it, and sold it to mitigate his financial loss.

Interestingly, it appears that the unit was dropped with enough force to that one woofer's basket. The cone itself is not at all damaged (except from being removed from the rubber surround), and the voicecoil doesn't show any sign of being hit by anything either. The only way I can imagine reproducing this damage would be to hit the REAR of the driver with something heavy, but that's not what happened either. Pretty weird.

Anyway... I'm just happy to bring this great subwoofer back to life, though the dust from sanding has made a mess of the place.

- Jason
 

MotorToad

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Dayum! Good luck with that. I'm once again impressed by the Brown Clown's ability to break things. Do they put the boxes in the trucks or drag them behind?
 

JasonR

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Here's a few photos of the top, after Bondo and sanding.

Based on the damage, it seems like the cabinet 'rolled'... perhaps right off the truck. Interestingly, this design does a pretty good job of protecting the sensitive bits, at least to a degree.

- Jason
 

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nsgarch

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You're doing a great job! And it's encouraging to see what's possible. What about the economics of the project (ie your time, costs, and what you paid for it?)

Finish suggestions? Well, you're obviously a very competent craftsman, so what were you thinking to do first -- two or three coats of automotive primer and lots of fine sanding? (I love those Wilson ads about how they finish their speakers!)

Color? Well, you're stuck with the black grills. If you want to do flat black again, the absolute best stuff (very fine velvety surface and durable) that I know is the Testors "Model Master" #1949 Flat Black spray enamel. It's for model railroad engines and available at most hobby shops. The one downer is it only comes in 3oz. cans but it really is the best stuff. I even use it on components.

Now if I were doing it, I probably would take it to some custom autobody/paint shop and have them spray it in their booth with some pearlescent blue or Shindo green and then have the aluminum ML top plate re-anodized in color to match -- but I'm kind of nuts that way ;-) Although the pictures from the recent factory tour indicate ML is now doing finishes like that on special order, so maybe I'm not so crazy -- wouldn't hurt to call them and ask?!
 

JasonR

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Thanks for the compliment, but as a craftsman, I'm really just barely competent enough to keep from severing digits. This is generally not the sort of project I'd attempt, but the seller happened to be local, and I have a Descent in nice shape that could use some very minor repairs that would necessitate similar work on the top panel. Better to experiment on a cabinet that's almost wrecked already. ;)

As for the economics, it really only works out if I consider that I've enjoyed the project (leisure time), have learned from it (education), and got a new tool as a bonus. The beat up Depth cost me $200. The replacement driver will be $165. Three new grills are $30 each. And then aluminum trim inlay on the top is $45 assuming it's actually available. Jim Power is checking into that. If not, I'll have to get creative with some back-painted plexiglass, or completely fill that area with Bondo which would be kind of a shame.

So... that's $500 in all for the parts, assuming I can get the trim. The Black & Decker palm sander was $40, and I spent about $20 on Bondo, some spackling knives, sandpaper, etc. A Depth in nice shape is worth around $850, so I could probably sell the finished work and still make a couple hundred bucks. If I keep it, it would be more economical to skip the grills since they're not necessary... but with my luck, I'll end up having trouble selling it at some point when the grills are no longer available.

As I said, I'm really not that much of a craftsman. The idea of a fine automotive finish is appealing, but that would mean a lot more prep work to get the finish absolutely 100% smooth. I think I'd rather just spend an afternoon with a spray can and see how it turns out.

- Jason
 

nsgarch

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Also, if you're thinking about resale, I guess flat black would be the best idea. I would still recommend 2 coats of gray sandable primer. It will fill and surface any exposed mdf giving a more uniform paint surface. If no top plates are available, I could have my machinist make you one (copy mine). Let me know, and if you want black or silver, and I'll let you know how much.
Neil
 

JasonR

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I'll buy some primer and give it a try. I know from experience that MDF doesn't hold paint very well. This material looks more like basic pressboard, but it's the same issue and has the same solution.

Thanks so much for the exceptionally kind offer to have your Depth trim plate copied if it's not available. I'll keep you posted.

- Jason
 

nsgarch

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I'll buy some primer and give it a try. I know from experience that MDF doesn't hold paint very well. This material looks more like basic pressboard, but it's the same issue and has the same solution.Jason
Make sure you use spray-can primer to keep a smooth base without too much sanding. If the mdf is pulpy in places (like where the corners got hit), saturate it with Elmers furniture glue, let it dry and sand it to a good contour, same as the bondo. Then prime.
 

eknuds01

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This is quite extraordinary. I have seen a few ML speakers damaged during shipping. It always hurts to look at damaged speaker cabinents. You are doing a terrific job! I would say you certainly have some skill (and a lot of patience) at smoothing out the corners.

Can't wait to see the finished product.

Erik
 

JasonR

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Thanks for the advice and encouragement, guys. I've done a little more Bondo and sanding, and it's certainly getting close to time for primer... perhaps this weekend if I can get the Bondo work completely done. It's pretty hard to keep very small air bubbles from getting inside the material, and sometimes these end up making an ugly pit in the surface after sanding. So I've been going over these... drilling out the pits into holes that will actually hold some Bondo well, and filling them with some pressure to drive any bubbles out. So far so good... I've fixed up 95% of it I think.

I'm going to try that trick with Elmers furniture glue on a couple areas where the substrate doesn't seem as dense as it should be. It's not pulpy, but the surface has some 'give' if I push... just like the outermost layer is a little soft.

Is Elmers furniture glue the same as their yellow 'wood glue', or is it a different product?

Thanks!

- Jason
 

nsgarch

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Jason, the stuff I've been using is a light yellow (like Elmers) called Titebond II. AT HD or Ace. Elmers is fine too. Just make sure it says 'weather-proof, or 'water-resistant' on the container.
 

Chops

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I love reading threads like this. Unfortunately, this one just dropped off the planet. Whatever happened with this project? Just curious.
 

peteynav01

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So I removed the woofers, amplifier/electronics panel, and transformer...
would it be possible for a better picture of that 6 pin connector on the transformer?? 3 of my cables came out and i can’t fuigure out where they go
 
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