Sealed sub: cabinet size??

[Klimon]

Hello!

I'm one of those cheap guys that does things as buying two dirt-cheap (discount car subdrivers, than hassles you guys with questions on how to make them work in a home environment

The only specs I have are: 91db/w, 4ohms, 21hz-800hz, max. 600watts, good build quality with plastic membrane and inverted dustcaps. I did a first test with a 60 liter (about 1,5 cubic feet) closed cabinet, didn't go low enough... Now building a 120 liter test cab which, when fully stuffed should give about 160liter max.

The way I see it I should be able to make it work when the cab is sufficiently large. I'm planning to power them with 41hz.com class T-amps, bridged, one for each sub. Biamping with crossover point around 80-100hz, simple cap as highpass, simple coil as lowpass unless this messes up the low-midrange, maybe an active filter with 4th order filter will be better on the long run.

Just telling my story here in the hope someone has any suggestions,

Cheers,

Simon

[GM]

Greets!

True, unfortunately, if it turns out to be designed for an I.B. (trunk) app, then it will require a huge cab for decent SQ/extension.

GM

[richie00boy]

Originally posted by Klimon
I'm one of those cheap guys that does things as buying two dirt-cheap (discount car subdrivers, ... how to make them work in a home environment

I used to do things like that until I realised it was a waste of time and money and effort. I suppose I learnt a couple of things though.

See how you get on with the larger box. If it's not so great, next time do some research and modelling before and buy right parts of better quality and do the job once.

It might be worth measuring the Thiele-Small parameters yourself just so you can see how bad the drivers are and seeing what effects the parameters have.

[ocool_15]

you didn't say what diameter they are. You will likely need to use some sort of active equalization to get a decent low end. Since its a car sub your Fs is likely to be too high, especially if its intended for a ported box. Its quite efficient which from t/s limitations is indicate it may not be as well suited to a home subwoofer application. You really need to measure the specs to get a better idea.

[Klimon]

I'll follow your recommendations and try to measure the TS-parameters, also because a ported box seems to have big advantages over a sealed one apart from the need for a precise design. The woofers diameter is 12" and the magnet weight is 50oz; I've seen other car subs with 100+ oz magnets so this might be a good sign: ib car subs tend to have a much larger magnet so mine might be made for ported / sealed use after all. Finally, I seriously doubt their 91db/w efficiency...

Thanks a lot for your input; I'll put this thread to rest untill the parameters are measured

Simon