Speakers: Hertz ESK 165S Component speakers
Source: Pioneer Premier DEH-P580MP
Amp: Xtant 404m (50w x 4 channels). (2) channels run to components in stereo; (2) channels bridged to 10" Image Dynamics subwoofer

My initial impression is that most likely everything is underpowered. I remember when an RF amp w/ 50 watts per channel would break windows...this Xtant is very clean, but the 50 watts per channel is really not as far-reaching as I had hoped. I think that with a few more watts, these would SCREAM. Note- evaluation was done first WITHOUT the ID10 hooked up, and later with it enabled.

The good news is that I could not push the Hertz to distortion without maxing out the volume on the HU, and that is with the amp's gains up around 90%. Like I said, the amp is clean, but just does not have a lot of headroom. The Hertz have very smooth highs and very clean midrange. I can get more true midbass if I lower the HPF to 50 Hz, but they sound very clean with the 80 Hz HP (I am using the built-in x-over on the Pioneer). I am sure that the speakers can take more than this amp can dish out. I jacked up the treble on the HU and still could not get the tweeters to sound harsh. These are very relaxed for sylabants (that is the "S" sound) and still remain crip. They are not one of those speakers that you have to turn up to really hear the details in music. The mids could take the bass being cranked on the HU, and were fine with the low or mid level of "Loudness" enabled. I never tried them on high, but they kept up easily with kick bass, with distinct "thwacks" for each beat. I had no trouble with muddiness or run-together.

As far as the presence, the sound seems to be at mid chest level. I would not mind it being higher, but a lot of that is the fact that the speakers are in stock locations, and with me being as short as I am, the seat is pulled forward pretty far.

Overall, the speakers are VERY musical, and don't sound like speakers- they make music sound like music. For the price, they are the best components I have ever heard or run. My only wish is that I had more power to put to them, and that I had a better-tuned sub to augment them.

Negatives: I DON'T like the thought of in-line crossovers, but they would be easy to upgrade, and they were a snap to install because they can be tucked just about anywhere. Also, the mids have a basket that seems a bit thin. I could probably torque the mounting screws enough to actually bend the basket/flange if I tightened them any more. You could see the mounting flange start to bend as the screws cinched down.