First off, I am a new user on this board, and a relatively new EMPEG Mark II owner (I got mine used). For now, I just installed the EMPEG as my primary source in my Honda CRX... but that is just temporary because I didn't want to wait any longer to start using it in the car (and I must say I really love this thing!).

I plan to add my OEM CD player back into the system (primarily for IASCA competition)..... the CD player has already been modified from the original installation - I removed the IC ampflifier and associated parts and added a discrete preamp output section that bypasses as much of the OE circuitry as possible....

My plan was to feed the OEM CD deck preamp outputs into the EMPEG aux input.... that way I don't have to mess with the OEM deck CD changer interface. For my intended usage, this would be ideal anyway since the the EMPEG will be the primary source deck 99% of the time, and the CD only used for competition or to play the occasional CD I haven't ripped and encoded yet. Therefore, I want the CD player out of the signal path when it's not use, so I can jjust leave it off and keep the audio path as direct as possible. That way, I can also use EMPEG's nice EQ on both sources as well.

But the problem that I came across is that I noticed that EMPEG specs indicate the frequency response is only to 18 kHz on the aux input for some reason.... does anyone know if that is real, and if so, what the roll-off rate is..... and why there is this limit? I would guess it is due to the the ADC used in the Phillips DSP chip or something in the analog path between the aux input connector and the DSP input (anti-aliasing filter, etc)? Has anyone experimented with ways around this (I2S directly into the DSP, or improved filters, etc)?

I also noticed that the output frequency response of the EMPEG is not specified anywhere I could find.... hopefully there is not something inherent in the Phillips DSP design that limits everything it processes to an 18 kHz bandwidth limit. I doubt that would be the case since I have heard this is supposed to be a pretty good DSP, which is why I am surprised by the aux input freq response in the first place.

I guess I will find out about the output BW soon enough when I go RTA my system at a local shop with ripped pink noise on my player in a couple of weeks.

Thanks for any info!