Car sub for home use

[batdorf9]

WinISD tells me that the W15GTI in the 8ft3 20ish Hz ported box will take around 800W from 20Hz up. So assuming there's a sub-sonic filter, 800W should be OK.

If you're looking for anything above 200W, chances are you're looking at pro-sound amps. There's lots of reasonably priced used pro-sound amps out there with this sort of power. A Crown K2 would certainly be sufficient.


- Robert

[simon5]

The 1000W plate amplifier from PartsExpress is a very interesting option too.

[tom daghdha]

How much are you looking to spend on an amp? You could use a pro power amp, but for one sub you'd want a bridgeable one (or two subs) and often there'd be fan noise. You could also get a lower model (new Carlsboro, ProSound etc) off ebay for probably less than £150 but you get what you pay for. As you're in Leeds you could look over to Rock Factory in Castleford, (site) or that new place on the Headrow opposite Argos, both stock power amps, but the latter is very expensive. If you know what kind of thing you want you'd be best looking on Ebay, I got a 1300w McGregor for £105.

CPC and Farnell also stock power amps, including prebuild plates to make active subs, but I don't think they go much higher than 300w and they tend to be pretty expensive.

[soundNERD]

I don't think you will want a ported box, espicially if you want it to keep up with the music. In a ported box it takes much longer to stop the cone from moving so its ready for the next sound, and, they are often more "thuddy" sounding and lack low-end response.

I'd suggest going for a sealed box and a little more power, or adding a passive radiator.

But if all you care about is seeing how many windows you can blow out, then you want a ported or, even louder, a bandpass box. But bandpass boxes are the worst sounding of all of them.

You really shouldn't need that much power. I've only got somewhere around 100-150W (not sure, it's an bridged OPA549 running at +/-22VDC, and I've don't know how to figure out the watts from that) driving an 8-ohm 15" sub, and it literally knocks stuff off of the shelves (and it's only a single, sealed, driver

[simon5]

Originally posted by soundNERD
I don't think you will want a ported box, espicially if you want it to keep up with the music. In a ported box it takes much longer to stop the cone from moving so its ready for the next sound, and, they are often more "thuddy" sounding and lack low-end response.

I'd suggest going for a sealed box and a little more power, or adding a passive radiator.

Sorry soundNERD, but that's not true. It doesn't take any more time to stop the cone, but it's true that there will be a delay around tuning if it's tuned too high. If he tunes the vented box under 20 Hz, he will have no problems with that because the delay is not in the passband.

I don't know why you recommend a passive radiator over a ported box. The group delay is even worse. They are a good solution if you want to use a small box because you can't make a vented box tuned under 20 Hz if the box is too small.

He will use this subwoofer for a big home cinema and for party so he want it to be loud. Sealed is the best for music, I agree, but vented is the best for movies and party. When tuned under 20 Hz, it's very good for music also. He also want to use 800W. To use 800W, he'll need to stay under 3 cu.ft sealed, which means almost no output under 40 Hz versus higher frequencies. Not that good for cinema.

For a vented box, he can go to 7 cu.ft tuned to 19 Hz and use the full 800W and have good output down to 16 Hz. 104 dB anechoic at 20 Hz sealed versus 114 dB anechoic at 20 Hz vented, the vented subwoofer will be two times louder...

[Sunil Banga]

Simon, I'm kinda understanding your reasoning. So you've worked out a 7ft cubed vented enclosure will be of optimum performance. What kind of diameter and length of port am I looking at? Also, I have loads of 1" thick mdf in my garage;; would this be sufficient to build it with??

[simon5]

Loads of 1" thick MDF will be perfect to build this enclosure.

You will need two 4" diameter ports 24" long, flared if possible would be better.

I'm talking about 7 cu.ft internal volume, so about 9 cu.ft external.