subwoofer basics?
 

i was lookin at subs and there are a ton of things i don't understand.

what does the weight of the magnet have to do with how good the speaker actually is? i see a lot of information with companies bragging about heavier and heavier subs with seemingly ever increasing prices to match, does it make that much of a difference?

when building or bying an enclosure, is the volume of the box just a blind volume, or do i have to account for the air space offset by the speaker and mega magnet?

what is the difference in sound between sealed box, band pass, and ported? what is the diffeence between ported and band pass, are they both just a hole for air to move through?

that is all for now. tia

IMO, go sealed, smallest space needed.

as for anything else, many people are going to have different opinions on every aspect, i dont feel like having to debate my ideas/experience so im gonna let everyone else do that, lol.

From what i did learn and was told, air space inside the box does not require you take into effect the displacement of the sub themselves. One tip if it matters any, putting cotton-type material inside a small box makes the sub "think" its a bigger box.

also 10's will have a tighter bass hit, but 12's are usually harder

then you also can deal with dual voice coil or single voice coil subs, 2 ohm or 4 ohm, and run amps in mono, bridged or stereo. one last thing, I dont belive in manufacturers RMS ratings.

that just sums up some stuff, like i said, everyone feels a different way on systems, so someone may say i said something wrong, but oh well. lol. My systems hit hard and clear, im satisfied and ive installed stuff in many friends cars.

what do you mean hit hard or tight? as in what range they work in or how loud the bass actually gets?

Ok, i used to sell this crap at Citcuit City; hear is the deal. Bigger magnet = bigger boom. Simple really, stronger magnet makes a stronger sub which makes a louder noise.

you can get specific and acount for the air space the speaker and magnet take up, but unless you're building a high (and i mean super high) $$$ compitition system, don't even worry about it. Just use a "blind" volume.

as far as boxes here it goes:

sealed hits tight (for like rock music), ported hits tight but also "thumpy". Band pass just, IMO, makes a lot of sh*tty noise. it is what 17 yr old put in their civics to act like they r cool. just loud bass.

I have a sealed 10" sub in my car and it hits hard and sharp as hell. but that is b/c i have a hatch back.

The size of the sub 10", 12", 15", ect also determins the sharpness and "thump" of the sound, 10" hits sharper, but 12" has more of a "thump" (this all of course depends on where the system is installed, and if you have a hatch or a sealed trunk.

if you want, PM me the type of music you like, what kind of car you want to install it in, and ur budget and i'd me more then happy to give you my $.02 if you'd like.

thansk guys.

one more question, how much does the shape of the box matter? there are a few ways i coudl build for the application, a tube would be very easy, a cube would work, a box that is deeper than wide would work. would any particular format sound better or worse over another?


right now i am jsut trying to get down the basic concepts. this is for an on again, off again project that i am supposed to do for a friend. i figure if i learn about all the stuff now and he finally decides not to do it, i cna still make the set up for myself just to see if i cna make it work.

weight of the magnet is how much power it can push on the speaker cone. The larger the magnet, the lower the frequency and how much amps or force it can move it.

The enclosure is typically (if done right) tuned so there are no resonant frequencies in the box or interfering with the sound waves coming from the cones. When building a box or buying one you have to take the physical presence of the magnet and cone into account to get actual air space volume inside the box. Wave interference is called 'standing waves' , or waves that resonate. Try and find a box that has no right angles. Front sloped slightly, sides and back too. That'll help a lot. You'll def notice a change in sound for the better. A lot of ppl just want that boomy bass that vibrates your car. If you do it right, you can get great bass response and still be able to hear the rest of the music. If you do it right like that, you'll also need a lot less power to move the magnets.

A sealed box calculates bass response in a closed enclosure and uses the air inside the box to boost bass frequencies. With low frequency sound waves, they are omni directional, or move in all directions when leaving the cone, but with very low frequencies, like with low bass sounds, they move in the opposite direction of the cone and want to wrap back around behind the speaker. With an enclosed box, you'll get a low and tight response, but they tend to be muffled and narrow in frequency. Band pass means that the box has been tuned to boost a specific frequency band, say like 60Hz. Great if you love that frequency, bad if you like to hear an accurate reproduction of whatever it is you're listening too. Ported is great if you put the box in the right place. Ported means that there are openings in the box to allow some of the air inside to move out. The ports are typically (if done right) tuned to the box to better allow the harmonic overtones to be heard. So if there is like a really cool bass solo in the song you're listening too, you'll hear it accurately as you would on normal speakers and not muffled like with a solid box.

tubes work good for frequency response, but cylenders create reverb over distance as the sound wave folds over itself. Would be cool for tweaters, but not bass enclosures. Cubes would be bad. You'd get standing waves on all sides and the box would litterally vibrate louder than the sound wave when it hit those certain wave lengths. So if the side to side standing wave was say 20Hz and the front to back 30Hz and the top to bottom 40Hz, anytime any of those frequencies was produced by the speaker, the box would rattle louder than the music. Create something with no right angles, thats how we design all the recording studios. If you go into a big pro studio, you'll feel a little weird at first as all the walls are on angles lol Try something looking like a trapazoid laying on its side almost. Flat bottom, slightly slanted front thats shorter than the back and narrower than the sides, top that slants upward to the back, and sides that slant inwards to the front.

the only word i understood in all that was trapazoid, but i think i get what you are talking about. fairly narrow box with the back of speaker pointed at the bottom rear corner of the box

Dont the boxes need to be calculated to the correct size (depth, width) for the speeker to sound right?? It really depends on what you like and listen to. I Have two 10" bazooka subs in a pre-made box, with a 250 watt amp, they sound good, and are not to overpowering but still very noticable (Im not a fan of thumping bass, rattles my brain cells, and sounds terrible).

Yes, included with every sub (at least the good ones) is a spec sheet. There is also a stat sheet that tells you the perfered box size that will best suit the sub.