This may get confusing but...

Jstas Posts: 14,718
edited January 2003 in Custom Fabrication
...I'm gonna ask it anyway!

A while ago, I came across a formula for speaker box construction. This didn't really apply to subwoofers. What it was for was for mounting a full-range speaker or coaxial speaker into an enclosure for things like a hatchback, a Jeep or a pickup that lacked rear speakers.

Basically, what the formula provided was a derived measurement of speaker enclosure volume based on speaker cone surface area.

I was wondering if anyone here had seen a formula like this or had it sitting around. I had it written down but I cannot find the paper.

The reason I am doing this is because I have a few old Pioneer speakers sitting around, collecting dust and just getting in the way. They are still useful and sound spectacular but I am afraid that if they sit around collecting dust, they will be damaged and wasted. I'd rathe use them. I don't have a vehicle to put them in so I want to build stereo boxes for them and run the with a pre-amp/amplifier for a lab I have at work. The lab could use some tunes badly and I'd rather not spend a whol lot of money on a stereo for work. If I can construct something to work well enough, I won't have to blow a pile of cash.

Any help is appreciated.
Expert Moron Extraordinaire

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Post edited by Jstas on


  • PoweredByDodge
    PoweredByDodge Posts: 4,185
    edited January 2003
    i haven't seen what you've spoken of, but i've got two general rules of thumb...

    for 6x9 speakers, reccomended enclosure is 0.2 - 0.3ish sealed or 0.5/0.6 with a "port" (nothing more than a 1.5 inch diameter hole drilled in the panel perpendicular to the cone face) per speaker.

    for a 6... i'd roughly guess it's probably like 0.15 ish sealed... or 0.4 - 0.5 with the port.

    polyfill if you do the port -- not a lot.. just a tad.

    or... you can go with a HUGE box --- something like 0.75 cubic sealed or whatever for a 6x9 // 0.6 sealed for a 6 inch --- the purpose being to "fake" free air... if you have that much air space for a little speaker, its ALMOST like its mounted in a door panel (what it was intended for in the first place).

    from personal experience, i've done the first thing -- had 4 pioneer 6x9's and then 4 polk DB series 6x9's off a 70 x 4 amp in a dual chamber box behind the seat of my pickup -- it was like 4 feet long -- 10 inches high .... 7 deep (internal dimensions)... had 2 of them off the right feed, 2 off the left -- or else i woudl have made it one big chamber instead of 2... worked out like .5 cubes per speaker... had two 2 inch diameter "port holes" per chamber... damn thing slammed... sounded like i had 2 10's and a set of crappy coaxials... loud as hell.
    The Artist formerly known as PoweredByDodge