[Weigel21]

Crazy idea to build an enclsoure to use JVC 6" woofers in car, looking for input.

So, yesterday I had a friend offer me the speakers from his old JVC mini system that had just crapped out. Speakers sounded fine last I'd heard them (months ago) and he claimed they still worked fine.

Anyways, I took them, I mean why not, they're free. So now I have them and no real need/use for them. Then I had an idea (probably bad idea). The little woofers in them actually produced a fair amount of punch last I remembered. Why not build an enclosure to use them in a car.

Yea, they're not designed or intended for such, but hey, it'd be something to keep my busy.

So, the speaker boxes have model number SP-MXGT80 on them and list the woofer as being 130RMS 6 ohm SVC. I could easily wire the two together to drop the impedance to 3 ohms and have a combined power rating of around 200-260RMS. Got an amplifier that could power them no problem.

The issue, they are housed in a bandpass enclosure with an unknown tuning, so I'm not even sure where to begin on building a small bandpass enclosure to put in a car. I can easily measure the internal volume of the sealed chamber, but the ported chamber is a bit odd. I seriously doubt there will be any parameters on the woofers anywhere to use a program to assist in the design, so I figure, why not ask for input on the DIYMA forum.

Thoughts/comments?

 

[Justin Zazzi]

Re: Crazy idea to build an enclsoure to use JVC 6" woofers in car, looking for input.

Is there something wrong with the current bandpass enclosure you are describing?

If so, it would be easier for you to measure some of the T/S parameters yourself instead of reverse engineering that box. It's not that hard actually, if you have access to some resistors, a volt meter, and something sticky like tacky clay.

 

[Lycancatt]

Re: Crazy idea to build an enclsoure to use JVC 6" woofers in car, looking for input.

I've done this type of thing before, never expecting much, and sometimes was surprised at what I got. Keep the sealed chamber the same size for woofer control/power handling, and then come closish to the ported volume, but slightly bigger. whats the worst that can happen..have fun!

 

[Weigel21]

Re: Crazy idea to build an enclsoure to use JVC 6" woofers in car, looking for input.

The little woofers are still in the factory speaker box, which house a mid and a tweeter, that I have no desire to use, not to mention there's that nice "Giga Tube" sticking out the top of the box and the wiring is but 18GA or so, which may be fine for feeding them power at 6 ohms, but I'm planning to wire them in parallel for a 3 ohm load and running just one run of wire to the setup.

Here is what the system was, the CD player died and he decided to trash the unit.

Access to resistors? Umm... whatever I can buy locally or online, if it's worth it.


Worst that can happen? I could REALLY mess things up and burn up the vehicle they get installed into. LOL

Seriously though, worse thing is they sound like **** or I blow them and it's just some wasted time and a few bucks in parts. Who knows, it might be entertaining.

 

[Justin Zazzi]

Re: Crazy idea to build an enclsoure to use JVC 6" woofers in car, looking for input.

Those enclosures look not too difficult to disassemble. Try Lycancatt's suggestion to measure what you have already. The see-through chamber would be referred to as the "rear" chamber and in a bandpass box. The volume of that chamber sets the power handling and low frequency response. Can you unscrew the front face of that thing and get your hands in there?

 

[Weigel21]

Re: Crazy idea to build an enclsoure to use JVC 6" woofers in car, looking for input.

The front section with the window is the ported section, not the sealed. I've already disassembled the enclosure to some extent, this is how I know.

 

[edzyy]

Re: Crazy idea to build an enclsoure to use JVC 6" woofers in car, looking for input.

Ha!

I got that same system for christmas back when I was 15.

Bass use to vibrate photos off the walls

 

[Weigel21]

Re: Crazy idea to build an enclsoure to use JVC 6" woofers in car, looking for input.

LOL, yeah, it's old, like 2001 or so, but it was still pumping up until a week ago or so. So long as it wasn't cranked up beyond 3/4 volume, it sounded fairly clean and was quite loud. Any further though and the sound began to degrade noticeably. I think it may actually prove to provide ample output in a car for the average Joe. May well do enough for me, though I was/am in the process of putting a Polk MM1540 in a downward firing enclosure into my car. Made a test enclosure with swappable legs, measuring from 2.5" to 4" in half inch increments. Weather has been poor lately to actually mess with the car outside, so the project has been curbed. Next nice day, who knows when that will be, I'll wire up the sub and my amp to test out and find the better performing clearance height.

Back on topic though. I'll take the enclosures with me to work and cut off the front to do some measuring. Then I'll get around to calculating tuning for the front chamber and finally, building a new enclosure. I work for a local lumber yard/hardware store/truss plant, so tools and wood are easy to come by.