Alpine 910 HU Distortion at Volume of +20
 

JL Audio TR600-CXi -Front Speakers
JL Audio TR690-TXi -Back speakers

Playing off CD/iPod music starts to Distort at Volume of +22 which is very low. Any ideas?

Head Unit Alpine W-N910

No amp yet. Soundwoofer turned off in menu, bass/treble at Zero.

Nice HU!
Do you know what the maximum volume level is? If it's 25 or so, the distortion is understandable.
Your drivers do seem compatible with the 18w/channel (CEA cert.) the HU produces. Have you considered some foam speaker baffles to help ensure they are not reaching mechanical limits too early?

Alpines have always gone to volume 35 and generally clipped pre out at around 28-31.

I think you will find that with an amplifier installed to power the fronts things will change. Not many people that buy that H/U use the internal amplifier and and volume 22 aint to bad for deck power. Also check that the crossovers in the H/U are not off or down below 70hz on those coaxials. Higher the crossover higher the volume capability.

You'll likely have to use a high-pass filter on the deck unless you amp them, or turn the bass down. I'd recommend between 60 hz to 80 hz.

Some valuable Alpine output info:
Built in amp (18W RMS x4) Max output/Clipping occurs around 20-22 Vol
Pre-outs (2v) Max output/Clipping occurs around 28-30 Vol
Pre-outs (4v) Max output/Clipping occurs Max Vol (35)

This should give you and idea of why you are experiencing what you around around 20 on the volume.

Not to sidetrack the thread here or anything but if you ever decide to sell you w910 let me know!