Subwoofer measurements

Independent testing of subwoofers allows buyers to evaluate them on a level playing field. Typically they are conducted outdoors using the ground plane method.

Things to look for in the results:

1. Extended bass response
2. Suitable max SPL
3. Low compression
4. Low distortion above 40 Hz and acceptable distortion below that point, with less attention paid to low orders of distortion (2nd and 3rd) and more to higher order distortion products

AV talk subwoofer tests >

HT Shack subwoofer tests >

SDX15 sub painted

SDX15 sealed sub now painted:

Black subs are difficult to photograph!

This is a sealed box sub for a CSS SDX15, downfiring. Sprayed with acrylic black. I had to call in some expert help with this one as I had a mismatch with gun and compressor. 

Room EQ example

In response to this SNA thread >

Before and after EQ.

You will notice how the 35 Hz mode still rings - it has been given some response shaping. However, the peak at 65 Hz has a higher Q peak and the EQ has reduced to Q of this peak, resulting in a better decay plot. As a result, it no longer stands out.

Spray painting booth

Recently I constructed a spray painting booth. 1.8m wide x 1.8m high x 0.9m deep.

It folds down into a smaller size with hinged sides and a top that comes off.

Shown above are some bass bins and surrounds I'm painting.