vic

I have four Polk 4x6's and a 5" Bazooka bass tube. The 4x6's are driven by a four chanel 200W Alpine and the bass tube is driven by a puny Clarion two channel. The high-end is fine, the mid-range is lackig and the bass sucks. I think I want to get two 8" subs, two 6x9's, keep the four 4x6's and loose the bass tube. So here are my questions:
How do you choose between 8", 10" or 12" subs?
What would the differnce be between one 10" sub vs. two 8" subs?
What is the difference between a sealed sub and one that uses a breather?
How does box volume affect sound?
How do you know how much power is necessary to drive the various sizes/brands of subs (or any other type of speaker)?
If anyone could give me some direction with respect to the selection of a sub or subs in terms of size, brand and ideal power, I'd really appreciate it...
BTW, if musical preferance has a role in the selection of components for this setup, I'm primarily into metal with the occasional jazz, classical and wrap. Also, I'm not interested in impressing the ricers with bass, I just want full high-quality sound.
Thanks.

KWB_S2

Here's my 2 cents:

1) Subs create bass by moving air. The larger the sub, the more bass you get (theoretically). The size of the sub will typically yield different types of bass, all other things being equal. 8"s are tighter sounding than 10"s, 10"s are tighter than 12"s etc. Typically the larger the sub, the more 'boom' you get.

2) Two 8"s push more air, so you should get more bass, and it should be tighter sounding (aka more accurate).

3) A sealed box is tighter sounding than a ported one. On the other hand you can get more bass out of smaller or fewer subs in a ported box.

4) Box volume is the most imporant thing when building a box. Every sub on the market has an optimal box size. They are all very different, so don't build one the same size as your buddy just beacuse his sounds good, unless you have the exact same sub(s).

5) Go with at least the recomended power for the particular sub you have, but be sure to buy quality power over quantity. 99% of all subs blown are from too little power, not too much. Buy a good brand like Eclipse, Alpine, Xtant etc if you can. If you see a 1000 watt amp for 99 bucks, it's probably junk.

Based on your music preference I would go with two 8" subs in a sealed box. Go with a good brand like JL Audio, Xtant or Boston Pro series.

PrerYDoG

I've put 2 8 inch Subs and am adding 2 5 1/4 woofers to my Porsche (In addition to 4 4x6's and 2 1 inch tweeters up front). The subs I built into the rear tire wells making custom boxes. In choosing what size speakers to add, you want to consider space in these cars. An eight will fit in the wells, a 10 will replace the spare tire. If you go much larger, you have a box taking up the entire rear hatch (Can you say "STEAL ME PLEASE").

As for box size, that is dependent on the speaker. I use Polk Audio 8" Punch subs b/c they needed only .33 cubic feet of box enclosure (the rear wheel wells are limited to about .35 cubic feet).

For both of these subs I use 1 200 watt amp in parallel and it delivers enough power to deafen you through ear plugs. You don't need a LOT of power, you need QUALITY power. A K-Mart special amp that says 600 Watts will not function and hold its power like a good Rockford or Sony carrying 200 Watts (there's some people who swear by the cheap K-Mart brand crap, ignore them).

Take advice, if you want Jazz and stuff, add 2 1 inch tweeters into your car (I put mine behind the drivers and passenger side air vents). Infinity IMHO makes the best tweeters out there delivering the best high pitch sounds.

For my 5 1/4's I'm custom building a molded fiberglass box along the rear hatch area that will easily be moved so I can get to the spare tire. They will be powered by a Rockford 100 (both amps placed around the spare tire under the carpet). This set-up helps me stay consealed, and delivers a deafening punch (Both in Bass, and trebble). It's nice. If you want pics of my setup, ask.


Mark

PrerYDoG

In addition, the guy who spoke right before me (I think we were typing at the same time), has good things to say. I especially like his 1000 watt amp at $99 comment!

slevy951

>The 4x6's are driven by a four chanel 200W Alpine

Great amp! Keep it! I believe it has a built in crossover, yes?

>How do you choose between 8", 10" or 12" subs?

Amount of money you want to spend. Amount of space you want to take up in the car. Or if neither of those is an object, personal preference.

>What would the differnce be between one 10" sub vs. two 8" subs?

See above. The 8's, in the right enclosure, have the ability to play better than a 10 in the wrong or average enclosure.

>What is the difference between a sealed sub and one that uses a breather?

Sealed sounds more musical, tighter bass. Ported are generally more power efficient and generally can play lower, but if not designed correctly, can sound really bad really quick. I prefer sealed.

>How does box volume affect sound?

Generally speaking, bigger box, lower bass. But, the 944 hatch is just about perfectly designed for getting alot of gain from small subwoofers.

>How do you know how much power is necessary to drive the various sizes/brands of subs (or any other type of speaker)?

I generally try to balance with the rest of the system. For what you have, I'd say around 100-150 watts would be fine.

You already have a great amp to build a system around. I have an 8" in the cubby in back that I can do for you. Pics at.....

Sub #1

Sub #2

Sub #3

Driver side version is also available. I'd probably take you amp, run front channels to front speakers. Disconnect the rears. Use the back channels on the amp for subs. This would preserve good front staging and give you excellent bass. I think you probably have more mid than you think. If you're interested in discussing further, email me off list.....

bs

most of these questions come down to frequency response and effeciency. smaller subs are more effecient (less mass to move => less power to move it) but they cannot play as low. an 8" sub isn't going to play very much below 30 Hz, whereas a 12 will get down pretty close to 20 and a 15 can easily handle 18 or so. However, an 8" will be downright loud on a 100W amp whereas the 15 will be barely audible.

so assuming you have 2 100 watt channels available, putting an 8 on each one gives you an assload of bass that won't really play those gut wrenching notes that you can feel 2 blocks away. but the single 12 getting 200 watts will give you slightly less loud bass, but will play deeper... good for the "wrap".

as for boxes, ported boxes are the boon of ricers everywhere who want everyone to hear their bass, but don't care at all if it sounds good. the idea of a port is that it causes the box to resonate at a certain frequency, making it _really_ effecient (more sound per amplifier watt) at a narrow range of frequencies. this gives you a lot of "thump" without having to spend as much money on amplifiers and subs, but it will never sound smooth or faithful to the original recording.

box size is a complicated issue involving the ideal compliance for your particular sub. go with the manufacturers reccomendations, which is usually a range. the upper end of the range (larger box) gives you a flatter response and slightly more low-frequency capability. the lower end trades these for higher effeciency.

manufacturers also give you a really good idea of optimal power.

if you are looking for a good thorough tutorial on the many aspects of subwoofers, check out JL Audio. they also make really good subs, which i would highly reccomend. I had two JL 12W3's in the trunk of my last car, each running off half of a PPI 300x2 amp, and it sounded DAMN GOOD.

marksportcts

This box was built for these Alpine 12"
Type-R, about 2.2cuft. It is built mostly out of fiberglass and little bit of wood. The center amp powers the subs, rated at 1500watts max (750watts per sub). The other 2 amps for the 12 mids/tweets.

bron964

vic - it seems like you've already gotten a lot of great advice...but i would like to make three comments. i agree with most of what has already been stated(especially with regards to BS' comments), but i would like to add:

(1) -as BS pointed out, a ported enclosure is tuned to play a particular frequency and to produce bass in a "narrow range of frequencies"...therefore SEALED boxes generally play lower and are more accurate/realistic.

(2) if you don't mind a box in the back, i would go with a single 10" sub designed for small sealed enclosures (e.g. .65cuft.) - with your listening preferences, the kick drum in metal will come to life, the bass guitar in the jazz will move the hair on your back, and the bass tracks in the "wrap" will keep ya head ringin'...ding ding dong...

(3) for total stealth with good bass - go with slevy's two 8's combo in the tire wells...very nice

good luck!
null

Matt O.

For decent sound at an inexpensive price, you can go with two 6x9 boxes in the back. I've mentioned this before, but I didn't post any pictures. I took some and if anyone wants to know how to go about doing this I'd be happy to help. You can get to the speaker wire without taking the inside panel off. And you give enough slack on the wire so that if you have someone sit in the back, you can put them in the hatch. I have my friend Phil to thank for this setup. He did this to a 951 he had and when he sold it the owner loved them (but you can easily take them out and revert to the original back speakers if you sell and want to keep them).