I'm going to break with tradition here, and post a review in this forum that's not a review of the Empeg Car itself. Since traffic in this thread is relatively light, I thought I'd take a chance and see if everyone would tolerate software reviews here, too.

Rjlov posted an alternate version of the Empeg kernel which adjusts the volume of tracks in real time. I was unable to try this out until version 11a of the kernel. But now, after a brief bout with MIME type errors corrupting the download (hey, Rjlov, zip that file on the server so others don't have the same error I did), I was able to run it this morning.

The purpose of the software is to change the volume of the tracks as you listen to them, so that the quiet bits are turned up louder. It's also intended to make the quieter songs in your collection fall closer into line with the louder ones. It's essentially a real-time normalizer. It sort of works like a dynamic compressor, although it's got some differences that make it sound slightly different (and better) than a compressor would.

I have to say, it's a success. It does exactly what it's supposed to do: It jockeys the volume of the tracks for you so you can hear the quiet bits better.

It's a little disconcerting to hear it slowly increasing the volume on the fade-out of certain notes, especially ones where you know the next bit's going to be really loud. At first, you get scared that the loud part will be way too loud. But it's coded so that the loud part won't clip- it has an emergency volume reduction part in the code. So once you get used to it, it's cool. It does what you would do in that situation (turn it back down when the loud part comes on), it just does it instantaneously for you at exactly the right moment.

I've only tried it with rock music so far. Since Rush is my favorite band, I've tested it on a few of their songs which I know have loud/soft/loud sections, and it works well in that format. The intro to "La Villa Strangiato", the "Discovery" and "Oracle" sections of "2112", the intro to "A Farewell to Kings", all work well. I haven't tried it yet with classical music, which I believe stands to benefit the most from this feature. Maybe it's time for me to find a good recording of "Bolero"...

I've also not listened to it in the car yet. I've only listened through headphones sitting here at the computer. If necessary, I'll add to this thread with updated information after I've had a chance to try it out in the car.

Although it works well, there's still some rough spots. First of all, it needs some read-ahead capability to reduce the "pumping" that can happen on certain songs. For instance, the "Soliloquy" section of "2112" has some pauses between the guitar notes where the volume of the waterfall gets pumped up unnaturally only to be cut down again when the guitar plays again.

Also, some work needs to be done on how it handles long fade-outs. It seems to drop suddenly from "amplified" to "zero" during a long fade-out. I know this was to compensate for it amplifying the track's noise floor unnecessarily, but perhaps there's a way to have it fade down instead of jump down suddenly?

Even with those minor problems, it still seems to work really well and I intend to use it on an upcoming road trip. We'll see how it does!

At the current time, it's just a proof-of-concept, and all the adjustment values are hard coded. What this really needs is integration with the player software, with the ability to turn it on and off from the menu, and editable parameters. Mostly, integration with the player software would allow it to do better read-ahead prediction and sound more natural.

I don't know if the Empeg guys have looked at this software yet. Guys? Have you? You should. I think this is something worth polishing up and officially including with the Empeg.

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Tony Fabris