bborzell

Well, I went to my local audio shop with test CDs in hand and started listening to HUs with and without outboard amps hooked up. The demo board had my speakers so all I needed to do was push buttons and listen.

The Pioneer P8MP was rated at a higher output (27 RMS) than the Alpine (22 or so), but while running each with its internal amp, the Alpine was significantly louder than the Pioneer.

I know that these things don't necessarily have related volume scales, but the Pioneer had to be set above 55 on the volume scale (out of 58 or so) to match the level I got out of the Alpine at 22 out of 45 or so.

The performance of each HU through a JL Audio 300/4 amp was a lot closer, with the P8MP sounding fuller and like the speakers were really relaxed (as opposed to stressed out) at fairly high volumes. Willie Gee described Focal PK165s as "singing" with a good amp and he was right. While the Alpine sounded good through the JL amp, it didn't sound as good as the Pioneer. Perhaps one reason is that the Alpine was putting out 2V to the amp and the Pioneer was putting out 6.5V.

What I don't understand, though is how or why the Pioneer sounded so subdued using its internal amp as compared to the Alpine even though it is rated higher in power. Maybe each head was set up differently with respect to gain settings for the JL amp. Anyone have a thought on this?

Willie Gee

Alpine has a more realistic power rating than Pioneer. But the hight volt outs will help you with the sound. Plus Burr Brown DA converter in the higher end pioneers are alot smoother IMO.

what did you like?

bborzell

As for the amps, I went back and forth between the JL Audio 300/4 and an Alpine (MRV-F345, I think). The JL was more suited to my tastes than the Alpine.

Running straight off the head units, I liked the sound of the Pioneer P8MP, but in order to get the same volume as I got from the Alpine (at roughly 1/3 of the Alpine volume setting), I had to nearly peg the Pioneer volume control. Makes no sense to me unless there is something off on the demo board setup.

At this point, with the unanswered question as to the volume issue on the Pioneer, I'm concerned that bridging the JL (150W) for the KP165s and running the CA130s off the head unit is going to be a drastic volume mismatch front to rear that won't be compensated by the fader control.

Willie Gee

Keep in mind that you are creating stereo sound, and not surround sound. The goal is to create a fantastic front sound stage balanced by rears that create "fill."

The front is where most of the music you are listening to should come from. Imagine that you are at concert, ideally equadistant from both monitors. The majority of the sound will come from the stage itself. Assuming you are indoors, a percentage of that sound will bounce off the back wall, filling the space. To recreate this effect is the goal of rear speakers. So when you are dialing in your fader, you do not want equal sound from front to rear, rather you want the rear speakers to be overwhelmed by your fronts, but without the rears you will loose the "fullness" of sound you gained by having them on.

This is why i believe the headunit has enough power to adaqautely power the rears. You're not really listening to them, but you can hear them.

When it comes to amps, bridging is only advisable for the subwoofer. You will be loosing stereo, and your fronts will be run in mono. Try out some more powerfull amps. Try to overpower your speakers by about 15-33%.

hope this helps

bborzell

I think you are right. I just got back from setting up an install. I'm going with the Pioneer Premier P8MP and the JL Audio Amp. The HU will power the rears and the JL will power the fronts at 150W. As it is, the JL is a 75X4 or 150X2 so I won't have a mono issue running it bridged. While they are in there, I asked them to run additional cables should I want to go for a sub in the future.

Looking forward to picking the car up in a few hours. I'll report on the sound. Thanks.

Willie Gee

good choice. you will have a great sounding system.