[sdiy] Hardware convolution box?

[cheater00 cheater00]

Hi guys,
does anyone make an inexpensive hardware convolution box with stereo
in/out? I need a couple secs of response at 48 kHz.

Has anyone considered using one of those inexpensive arm based
mini-pcs for this purpose?

What sort of processing power does one need for convolution? I'm not
sure how to calculate this. My calculations were: to apply a
two-second IR at 48 kHz onto incoming 48 kHz signal, you need, per
channel, 2*48000 multiplications for each sample being put out. You do
this 48000 times per second. So in the end for each channel you need
2*48000*48000 multiplications per second, or 4608 MIPS per channel.
Then you need to do the additions as well, and then account for the
other channel. That's a whole lot. Am I missing something?

Thanks