[LAD] what does "full range" mean with regard to ambisonics and speakers?

[Jörn Nettingsmeier]

On 08/03/2010 07:45 PM, Fernando Lopez-Lezcano wrote:
>
> Hmmm, so, you send WXYZ to the four subs and whatever order you can
> decode to the regular speakers (6, 8, etc). Sounds good.

it does :) except you'd usually throw away z, unless you wanted to try a 
tetrahedral setup for the subs (for example: front left floor, front 
right ceiling, rear left ceiling, rear right floor). this setup is known 
to be unstable for full-range use, but could work great for bass, 
depending on how far your subs have to reach up. then again, i'm not 
sure if the rigging hassle is worth the z information in the bass.

> What if you want to include a crossover? (that's exactly what I'm
> working on right now in the openmixer software).
>
> So, you high pass WXYZ and send that to the regular speakers, low pass
> WXYZ and send that to the subs... and what do you do with the rest of
> the Ambisonics components? I imagine I would just send the full
> frequency range to the regular speakers and let them do the best they
> can, right?

hmm, i think i would rely on the internal electronics of the tops for 
the HPF and feed them a full-range signal of all components, and then 
maybe measure one and design a suitable roll-off for the bass 
speakers... but i have never had the luxury to do that, i always set the 
LPF by ear.

sending high-passed WXYZ and full-range higher orders to the tops won't 
work well, i guess. if you want to take care of the band-splitting in 
your mixer, your best bet would be ganged high/low-pass filters for all 
the orders. if you have the time, gear, and expendable ph.d. student 
labor at hand, it would be fun to try three- or four-way systems with an 
increasing number of speakers as the frequency goes up.
but since the most expensive part for massive ambi systems is the 
amping, that's probably an economic dead-end, at least for now.


best,

jörn