Small 10" sub project

[d1030180]

Hello

I finished building my little sub project. I wanted to build a relatively compact design with volume of approximately 30..40 liters.

I measured the T/S parameters of the woofer, and closed enclosure type was chosen as the driver has a medium Q value (Qts=0,48) and quite low resonance frequency (Fs=30,4 Hz). Also it might be tricky to fit a long and wide enough bass-reflex tube for ~20 Hz tuning inside such a small enclosure. The total Q value for the driver in a 38 liter closed enclosure would end up in the "optimal" range of ~0,7.

The backside has a modified 120W plate amp. Originally it had an unadjustable 2nd order +6 dB@40 Hz peaking highpass filter. By changing some components on the PCB, the filter was modified to a flat frequency response. With these changes, there is some output down to ~25 Hz when the crossover frequency is adjusted low enough to integrate with the main speakers. When I tested it with some 16..17 Hz sine signals, the windows of my house started to vibrate and it made me flinch!

Scan-Speak's 10" woofer 26W/4558T00 would also fit this enclosure well. Using this driver might improve the bass extension to some degree.

So far I am very satisfied with the performance of my first DIY subwoofer.

[Brian Steele]

Originally Posted by d1030180

So far I am very satisfied with the performance of my first DIY subwoofer.

Nice work. Which driver is that? It looks like a car audio driver...

[d1030180]

Thanks,

I don't know the brand/model. But according to the measurements, its electro-mechanic parameters are:
Fs: 30,4 Hz
Qes: 0,54
Qms: 3,4
Qts: 0,465
Vas: 48,27 L
Sd: 335 cm²
Re: 4,1 Ω