View Full Version : Has anyone built enclosures for the front 6.5" speakers?

08-11-2004, 12:12 PM
After listening to some different setups, I've decided to install a set of mb quart nka119 (6.5 coaxial) speakers in the front factory location, amplify them, and use an old automotive head unit. I listened to this setup in a store, and I think it will be a nice sounding, pretty simple system. Their two big recomendations were that I amplify the speakers (setting to low pass, 55Hz), and make some kind of enclosure for the speakers. I was wondering if anyone has done anything similar to that, and might have pictures to share. I was thinking of something as simple as finding a large enough tupperware and tacking and sealing it in against the wood panel.


08-11-2004, 11:57 PM
I think Crutchfield sells a foam backing enclosure that you can fit the speaker into and get better response.


08-12-2004, 12:37 AM
You need to set it to high pass for the 6.5", so nothing lower than that goes to them. Low pass is for sending anything below that crossover point to the amp(active crossover) or speakers(passive crossover). If the system has a subwoofer, you should set the high pass to about 100-120 Hz. There's no need to send bass to speakers of this size, especially if they're being used outside, with a sub.

Re: the Tupperware- I don't know of a glue that will stick to this kind of plastic very well. You can make the enclosures out of fiberglass instead. The enclosures will definitely add to the efficiency of the 6.5", too. If you do use Tupperware, you could cut off or grind the ring that the lid mounts to and leave the flange, then make a ring that would screw into the back surface of the backrest, holding the Tupperware in place. Seal this and the hole for the wire to go through.

09-05-2004, 09:34 PM
I ended up buying a pair of mb quart 6x9's off ebay instead of the 6.5, but I haven't installed them yet. I'm wondering if I need to set it to high pass for the larger speaker? I still plan to hook them to an amplifier.

I gave up on the tupperware idea b/c the area behind the speaker is too irregular for it to work. I also tried spraying insulation foam in a trash bag to make a form to lay fiberglass on, but that didn't work either, as only the outermost foam would dry and expand. Finally, I would think making something out of plywood would be even more difficult. Any thoughts or ideas?

So, I'm running out of ideas, and am thinking of leaving them open in the back. I talked to MC, and they said that not even their most elaborate stereo systems use enclosures, and they didn't think they were needed.

09-05-2004, 10:46 PM
As long as they fit, 6x9's will sound fine. You still want to set the amp running them to high pass so they'll handle more power.

If you want to build enclosures, start by making up a block of foam insulation, just about the size you need. Carve it with knives so the rough shape is close and use rasps to get it to the right size. Cover it with masking tape so there are no gaps and lay the fiberglass over it in multiple layers. Add enough layers so it will be about 1/4"- 3/8" thick. When it has set, drill a hole in the area where the speaker will be mounted so you can cut and scrape out as much of the foam as you can. If you want to deal with the fumes, acetone will dissolve the foam, but it's toxic and if the dissolved foam gets on anything, it's not gonna come off easily. Peel the tape out and cut the rest of the hole out for the speaker and where the wire will go in. If you wash the shell out with acetone, it won't be sticky.

09-05-2004, 11:05 PM
DWE; that one response make me think MC should have a partnership with Nakamichi or equivalent to really evaluate this aspect of boating. You see so many companies do this, none in boating yet.

Sorry, agree, the present speakers don't sound that good and enclosures and other things could really help, glad to see separates in the new boats.

09-10-2004, 01:55 PM

What is wrong with a $8.99 speaker baffle and then harden it with Fiber if you would like to?

09-10-2004, 02:03 PM
I agree, that foam thing is the way to go for a ton of reasons... 6x9 may not even need an enclosure if you want to try it without..
One other option is to run an amp to your stock speakers and you'll be surprised how much better they sound with some power behind them..

09-11-2004, 02:26 AM
I emailed mb quart to ask their opinion, and this is what they said: The 6x9's do not need any type of enclosure at
> all. They are made to run free air.As for the
> crossover settings I would set it on high pass as
> well and then set the crossover around 100 hz. That
> will give you some bass and not damage the speaker.

However, I noticed this in the instructions: "an enclosed
volume of at least 6 - 15 liters is requ;ired for the
best sound reproduction."

I did look at the foam enclosures, but from my quck calculations, they won't come close to having the recomended air space? And, I didn't see anything for 6x9's. I emailed this back to mbquart, so I'll see what they say.

09-13-2004, 10:13 AM
The foam is to keep the low end sound waves from just dispersing into a void. The high end notes do not need an enclosure at all. Unless you are running a sub you shouldn't have any problems mounting the 6x9 without an enclosure. They are designed to be mounted in rear decks of cars. I run a 12" free air Kicker with no enclosure and it shakes the boat with crystal clear lows.