Tuesday, January 13, 2009

Determining range and crossover

Nice to get some responses to my last post. I notice some heads go up when there is new horn matter created!

I have been playing with the crossover function of Foobar (it's a third party plugin) to investigate how much range I would like and what a 100 Hz crossover sounds like. I have added a screenshot, because it shows sooo much.

What you are looking at, is a two-way setup, crossed at 100 Hz at 24 dB/octave. The top two tracks of the oscilloscope are below 100 Hz, the two lower tracks are above 100Hz. This is with reggae music (bass heavy). Visually, it already indicates the difference in frequency and amplitude. The difference in amplitude is less pronounced with acoustic classical/orchestral music, but the overall impression remains. This is why basshorns must be large.

Next, I kept lowering the crossover point, to where I wasn't hearing much. Although reggae and other music with electric bass guitar isn't supposed to go below around 40 Hz (38 Hz, or 38.8 Hz or whatever according to whoever you are speaking to), I was suprised to learn that I still have all kinds of musical sensations even when crossed around 35 Hz. Even at extremely steep crossover slopes. I could follow the bass lines, both rhythmically as pitch-wise. Reggae is extreme in this area, with strongly accentuated low bass, and I listen to a lot of reggae. It seems it makes sense going for quite a low cut off.

I think I will aim for around 30 Hz lower extension, or lower. I'll compile a shortlist of ready designs next time, or maybe come up with some new design sketches.

1 comment:

Mike said...

A few years ago,I did a similar thing-I measured alot of my music with adobe audition,did a FFT spectrum analyse of it all - took a while.
I noticed that a -3db point of 40hz would do,mostly, for some material infact itwas nice to get the physical presence of that 32hz information,on the odd occasion when it did present!

In the end I got a jbl2226 on a
large 175L enclosure tuned to 32hz.

I do miss that beast!
Mike_NZ