New guy looking for help with 2005 GTO in San Diego area

**soundman98** · 04-12-2011, 06:24 PM

sound quality is always personal taste..

i have run both the dock connector, and the headphone jack from my ipod to my car's amps at different times-- at first, i had a pioneer deck, with ipod adapter, and after that deck died in a unfortunate troubleshooting session, i ran my system using the headphone jack of the ipod.

the biggest difference was the eq settings-- when the eq's were flat, i could never tell a difference..

and i can pick out the difference between my flac files, and my old itunes-downloaded stuff(i think they provide songs at 120-180kb/s?)...

the other thing at play is the different amp stages.

when you use a ipod's headphone output, you are going through the ipods internal headphone amp, and then going through the external amps amplifier circuit. this can cause a lot of signal degradation, or cause some odd audio quality issues.

by using the dock connector, you bypass the ipods internal amp, so you are only using the external amps circuits. which, if the ipods amp was causing problems in the first example, this would correct that as well..

but, i really hate bose.. they tend to use cheap materials, and also use psyco-acoustics on some of their products to make them 'feel' like they sound good...(there are tons of articles on this-- just search for "why is bose bad?")

the difference you are hearing between the two setups you described could have something to do with the poor way that bose built their equipment..

using the dock connector, would be pretty easy to setup-- there are some videos on youtube by a car audio shop-- soundman car audio, they have recently become very well known because they have started doing a lot of work with integrating ipads in cars.

the most common device they use is the jl audio cl-rlc preamp/volume control.

this is the only remote volume control on the market like it, and it works great(i have 4 of them).

**BobMajerle** · 04-15-2011, 12:45 AM

I'm playing mostly flac, so I'm hoping to find a way so that I can't tell the difference. The bose sound dock was actually the one that sounded good, it's the headphone jack to receiver that sounds bad. I guess I'm just hoping to find a way to get a digital signal from; the ipod (running rockbox), a tablet, a zune, or any device that can do playback, by using USB. There doesn't seem to be any receivers that can do this.

One of my questions; do most USB DACs require drivers and basically only work with Windows or a linux OS that might have drivers? Or are they almost bypass devices that will take any digital audio sent to it and convert it to analog and ready for an amp?

If I am stuck with using 3.5 mm, does anyone see a problem with going from; digital (ipod), to analog (3.5 mm), back to digital (DAC, receiver, or dsp) and then back to analog and ready for an amp. It seems to be I would lose a lot through that process, but thats what I'm here for. If there won't be a noticable difference through that process, are there impedance issues when running a 10-12 ft 3.5 mm cable from the trunk to the dash?

I can't find much at all on the Alpine PXE-H660. Theres only one thread on page for of the link below on page 4, but it doesn't talk about the device at all. Does anyone have good things or bad things to say about it? I realize this is an integration peice, and that it won't help me with USB, but is it worth the $300 on a budget system?

http://www.mp3car.com/worklogs/14240...cab-build.html

**soundman98** · 04-15-2011, 06:04 PM

1. digital/analog/digital/analog: yes, that is a lot of conversion. while there will be some info that gets lost because of it, but it depends on the quality of the conversion process that determines if you can hear the difference. i would really just leave it at one conversion-- just use the 3.5mm out of the ipod, and go straight to the amps..

2. Alpine PXE-H660:
this is a DSP-- basically, using a pc, you can setup the eq curve, time alignment, and other speaker parameters to get your sound system tweaked to your liking.

i can't say that this product is good/bad, because i've never used one, though the IMprint tech looks really cool, and i really haven't heard too much bad about alpines DSP's...

for the cost being worthwhile--when using a ipod-type source, i would prefe,r, and recommend to have some adjustability in the sound controls, and not to rely solely on the devices sound-controls. this could be anything from a $25 7-band eq to a fully featured dsp like the alpine unit you linked to.. i don't think that there is a 'perfect' product..

dsp's are great for when you have the source-unit worked out, but want extreme-adjustability, but cost more.
1/2-din eq's are great for the simplicity, and ease of quick adjustments, are usually cheap, but you won't have TA, or other dsp adjustablility...