Found this large JVC loudspeaker cabinet outside and wondering what to do with it.
You can see all the drivers have been mutilated and there's only their driver frames left:
The back MDF panel has a large hole in it:
I am wondering whether I can re-build a single cabinet from it and put my Logitech subwoofer driver in it instead of its current enclosure. Also wondering whether there's a good way to repair that MDF hole or if it's preferable to just make a new MDF panel to go with it.
Suggestions are most welcome.
You can see all the drivers have been mutilated and there's only their driver frames left:
The back MDF panel has a large hole in it:
I am wondering whether I can re-build a single cabinet from it and put my Logitech subwoofer driver in it instead of its current enclosure. Also wondering whether there's a good way to repair that MDF hole or if it's preferable to just make a new MDF panel to go with it.
Suggestions are most welcome.
Attachments
Measure the Logitech's TS parameters and then simulate so you know
if it would be worth repairing.
Making a new panel would seem to me too much of a trouble. Take a piece
of panel larger than the hole, set it over the hole and make a marking so you
know where your router should go. Make a rebate for flush mounting a new
panel. Your new piece would have to be less thick than original depending
on routing depth.
I don't know if that makes any sense to you.
Well, the boxes are salvageable inasmuch as you could patch them up. But if you're planning on dropping your Logitech sub in them, a number of points come up:
-You'll need to ascertain if the Vb of the patched up enclosure is appropriate for said sub, and adjust the tuning appropriately.
-You'll need to fabricate new front & rear baffles assuming you want a vaguely attractive finish.
-Again, assuming a vaguely attractive finish, you'll probably spend more time & effort patching up the clapped-out JBL boxes than you would building a new cabinet. Especially since (if you have any specs. for your Logitech unit) you will have more flexibility to adjust volume & tuning, and can probably build a better / stronger / stiffer cabinet.
-With the above in mind, frankly, I'd break them up, unless you just want to have a bit of fun experimenting with the Logitech in a different volume. The balance sheet comes down in that direction. You might be able to salvage some of the material so it's not wasted.
-You'll need to ascertain if the Vb of the patched up enclosure is appropriate for said sub, and adjust the tuning appropriately.
-You'll need to fabricate new front & rear baffles assuming you want a vaguely attractive finish.
-Again, assuming a vaguely attractive finish, you'll probably spend more time & effort patching up the clapped-out JBL boxes than you would building a new cabinet. Especially since (if you have any specs. for your Logitech unit) you will have more flexibility to adjust volume & tuning, and can probably build a better / stronger / stiffer cabinet.
-With the above in mind, frankly, I'd break them up, unless you just want to have a bit of fun experimenting with the Logitech in a different volume. The balance sheet comes down in that direction. You might be able to salvage some of the material so it's not wasted.
Well at least the foams look fairly intact! lol Seriously though, I've taken on some "lost cause" speaker projects in my time. But those look like they suffered through a drunken college frat party. You'd be way better off building a cab for that sub you are talking about. I'd take that cabinet out in the back yard with some lighter fluid and a bag of marshmallows.
Hi Lojzek,
Thanks, that's exactly the kind of reply I am looking for, i.e. whether it's technically feasible to enclose a sub in a rectangular cabinet, what the dimensions should be, ported or not ported, etc...
Speaker cabinet construction is new to me, but I know I need to do some calculations and simulations. The plan is to be able to re-use as much of the enclosure, to patch it up and install the Logitech sub within it.
The enclosure might need additional bracing, and of course, sanding and painting, additional acoustic damping material, etc...
The routing is beyond my ability for now, unless I can rig something up with a Dremel.
I did think of patching the hole at the back like you mention, with another piece of scrap MDF and wood glue (yellow, quite strong, which I am using for my tube amp frame).
I'll definitely need to also patch a few of the round holes for the previous drivers. Maybe one of them can be re-used for the sub driver but then I'll need to verify if the placement is okay.
Hi Scott, yes these are the lines along which I was thinking. I suppose I should try and get the actual driver specifications and/or map out its frequency response and aim for tuning the enclosure to reinforce the bass where the driver drops off, correct.
I am interested in speaker building but the details are unknown to me, so if I can have any pointers for Ts, VB, etc, do let know. I'll be looking out for a good guide on the internet through Google for sure.
I have a couple of options here:
- Patch the hole in the rear baffle
- Make a new rear baffle (I think this is more difficult if I don't remove the front baffle first.
Time isn't an issue - budget is. To make a stronger cabinet, I intend to add braces as needed with existing salvaged and remaining wood from my tube amp build.
As mentioned in my first post, that's exactly what I had in mind.
Cheers!
Madtecchy, true, true!
I was just looking at some speaker construction articles last night and saw superimposed MDF and particle board.
Particle board it is. I would have preferred MDF.
I am still planning to patch it with MDF though as I have some.
The following opinion is completely prejudicial towards that Logitech sub driver. 
I assume it is of the low-sensitivity for a small enclosure type. Perhaps the JVC box can be sawed right above the large rear panel hole and a new bottom installed without invalidating the volume required for the driver. Naturally, measuring said driver's parameters is where it's at ultimately.
Try to kludge something up before even thinking about making this box pretty. This is where I'd put a stop as the quality of construction is probably not that great compared to the time usually needed to beautify an enclosure.
I assume it is of the low-sensitivity for a small enclosure type. Perhaps the JVC box can be sawed right above the large rear panel hole and a new bottom installed without invalidating the volume required for the driver. Naturally, measuring said driver's parameters is where it's at ultimately.
Try to kludge something up before even thinking about making this box pretty. This is where I'd put a stop as the quality of construction is probably not that great compared to the time usually needed to beautify an enclosure.
Thanks IG81, hadn't thought about sawing the bottom, but it's a great idea too.
I still don't know how to do the measurements yet, but I have been looking for specs of the Logitech. It's a z623, not great quality for music and audiophile listening, so if I can hack something new and better with it, including its amp and crossover, I will.
This is a fine technique if you have an amp, multimeter, ~10ohm resistor and a signal generator, which can be a free program for your computer.
Measuring Loudspeaker Driver Parameters
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