More on this:

Firstly, the box would store all its configuration in a manner similar to the empeg. In other words, you can take the box to any PC running the appropriate software and it will load up the 3D map and other parameters from the box itself. You don't need to take the parameter file around on a separate floppy or computer.

The parametric EQ on each output would be used to provide filtering to match speaker type - i.e. the EQ is used as a low-pass filter for the subwoofers and a high-pass for the tweeters, etc. I'd rather keep this in the EQ than provide a 'low-/high-pass' filter in addition to the EQ (which is quite powerful enough).

However, from what I know of psychoacoustics the ear uses frequency response characteristics to determine the horizontal position of a sound. For instance, sounds from behind you lose some of the high frequency component coming around the lobes of your ear (some people theorise that this is why the ear is shaped the way it is and isn't just a hole in the side of your head). If you hear a sound that's slightly muffled in that particular way you associate it with something behind you. Another aspect of this is that you're used to birdsong and wind noise coming from above you, and animal growls and thuds coming from below, and this may go toward your vertical positioning of a sound (I don't know if this is actually true, but I was told it was by a reliable source).

Would this mean that it would be necessary to 'correct' the signal coming from a speaker behind you for the high-frequency loss from your earlobes? I don't think it would be that significant - after all, we seem to do pretty well in car stereos as it is - but I'll research it. But for user input do you think this would be a useful thing? or would you prefer to set the EQ yourself and know exactly what it was?

If there was some way of getting the MP3 stream straight out of the empeg, then I could also implement MP3 decode in the box itself. This would mean there was only one DAC step (instead of a DAC in the empeg, an ADC in the box, the DSP, and then another DAC in the box for the outputs). Of course, it can't be the RS-232 output from the empeg, because that's got a maximum bandwidth of 115kbps - less than the 'standard CD' encoding of 128kbps. And, of course, we can't use the USB. The only option left in the current configuration would be to have the box talk ethernet to the empeg - doable but it would significantly increase the cost of the device (I imagine).

I think Hugo mentioned (I think) that there's an unused I2S header on the empeg - a digital out, in case you didn't know. Can someone in empeg confirm this, and tell me how practical it would be to get this to an external connector? That would be the raw audio stream, but that's perfectly acceptable (and saves the box having to buy a license from Fraunhofer for a decoder). A feature for the Mark III?

Keep the feedback coming.

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