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View Full Version : Hey Pyro (Chad)



Quinten
05-10-2008, 09:03 AM
You seem to be knowledgable on the audio stuff, so here's my question. I purchased a relatively in-expensive Sony stereo kit from West Marine. There are 6 or 6.5 speakers in the kit, bi-axials I think, but do I need to build enclosures for these to get the maximum benefit, and if so how much space and do they need a vent. I think the only location I really have good space to put them is in the gunwale area, but without cutting into the side. I thought maybe a panel installed from the bottom of the gunwale to the top of the outboard stringer. Half way between the front and rear seats. Any thoughts?

pyro
05-10-2008, 09:20 AM
The panel is a good idea. It needs to be rigidly mounted, so the cone(s) can vibrate while speaker itself remains rigid and stationary. The panel needs to baffle the speaker so that sound waves from the front and rear sides don't "cancel" each other out, killing bass tone. Usually an enclosure accomplishes this. If you use an open free-air baffle like a panel, it ideally needs to have at least the speaker's diameter worth of baffle on every open side of the speaker to sound decent. This means the baffle would need to be at least 18" or 20" wide to sound good with a 6" or 6.5" speaker mounted in it. Any sound waves with wavelengths longer than the "wrap-around" distance from front to back around speaker baffle, may tend to be cancelled out. Lower bass means longer wavelengths. In other words, the larger the baffle board, the better deep bass and mids the speaker will produce.

I went with a pair of 6x9 wedge boxes in mine. This allows the speakers to be laid out on the back seat or the bow at several different angles. I can also remove the deck and speakers at any time for weight savings while making top end runs. It's hard to find the boxes with the right shape that will fit in there. They tilt up for good projection. If I flip the boxes over, the shape of the boxes will make the speakers straight up-and-down, fitting perfectly between gunnel and stringer.

http://img528.imageshack.us/img528/1080/v6kg0.jpg

http://img291.imageshack.us/img291/3386/v4rm7.jpg

My deck is just laying beside the drivers' seat in the side compartment. If I want it out, I just disconnect it and remove it. ;)
http://img145.imageshack.us/img145/4103/v2dg8.jpg

Quinten
05-10-2008, 08:42 PM
Good info Chad, I appreciate it. I'm inclined to try and stay away from a large surface area or foot print if you will, so I was thinking of keeping the panel rather narrow. If I want to keep it narrow, can I do so and just add depth on the sides? I guess it would be kind of like a vertical U-channel in a sense. BTW are yours kind of wedged in there, how do they not end up by the trim pump. Thanks for the help!

pyro
05-11-2008, 11:31 AM
What trim pump? I have a fishin' 200 mid with 3-ram trim. :D

You can wrap the panel around, so to speak. But, if it's going to bend around to the sides anyway, why not just build some custom cabinets with a small footprint?

If you use smaller speakers like 4" or 5.25", you can mount those on a small baffle because they have weak bass response anyway. Add a bazooka sub to handle the bulk of the lows and midbass, and you'd be set.

Quinten
05-11-2008, 12:15 PM
I thought I had a fishin motor, but my trim pump is under the splash well with a single ram trim system. :confused: Still learning.

Any way, I think we are saying the same thing, I was implying that if I built a panel alone that it would not do the speaker justice. So my question, I guess, is it necessary to put a back on the box, or should I leave it open. They are 6.5 inch speakers, so I'm looking to make the most of them. Secondly, is there any thing to be said for box volume in a speaker of this size and quality. I can only assume they are a free air speaker, so would there be a big difference in .5 cu/ft vs. 2 cu/ft. I want to get the most out of these and then add two more or a sub later.

I do kind of like the idea of the boxes, you can try a few things and locations without the commitment of a custom build. Also, at this point, I know I don't have the watts to listen while running any way, so this will be for the hanging out music on the sand. Maybe I should just find some boxes for these round 6.5 inch speakers. Thanks for your time!

Quinten
05-15-2008, 07:28 AM
Soooooooooo Chad, Do I need to worry about the cu/ft of the enclosure I want to make?

pyro
05-15-2008, 08:38 AM
I thought I had a fishin motor, but my trim pump is under the splash well with a single ram trim system. :confused: Still learning.


Oops. I'm forgetting that they were ALL single ram until (late 80's??)


I was implying that if I built a panel alone that it would not do the speaker justice. So my question, I guess, is it necessary to put a back on the box, or should I leave it open?



Do I need to worry about the cu/ft of the enclosure I want to make?

If you make an enclosure, make it big. Small enclosures choke bass response. Too small a baffle makes the mid-bass strong and "woofy" and kills a bit of the lower-low-end due to phase cancellation, but if you're planning on adding a sub anyway, don't worry about it. Set the amp to high-pass the main speakers at a given frequency, say 80 hz, then set your subwoofer's low-pass crossover at the same frequency. The sub will take over where the 6.5's leave off...

-Chad

Quinten
05-15-2008, 08:46 AM
Thanks Chad, I appreciate it!