CarPC/Carputer pics and wanted advice

[qbunnie]

Well, I finally did my install of my CarPC. It's in its initial stage, so right now all it has is my music and GPS navigation (using iGuidance 3). I can also put videos on there, but I haven't bothered. I was trying to do phone control as well, but found out that my phone is limited, and since I'll be getting a new one soon, I'll just integrate the new one in the next stage.

What I need advice on is my audio sometimes has a static hiss. I hear that this is a problem with poor sound cards, particularly laptop audio. It comes and goes, but it is pretty annoying. Does anyone know a way to reduce it without buying a new sound card? The audio is integrated through an aftermarket radio amp using an auxiliary input. Thanks! Enjoy the pics.

I'm about to go back to school, but I'll try to answer any questions for the next couple of weeks. Thanks again.

[slvryaris]

Whats the actual unit in your dash?? Sometimes bad connections at the patch cords can cause it.

[qbunnie]

the deck is a JVC KD-HDR1, which is in the glove compartment.
the audio cables run from the deck to the computer itself. I've connected and reconnected them a few times, with no noticeable improvement. I even tried switching the cable itself, still nothing.

[slvryaris]

Sorry I meant the computer and the screen.

[qbunnie]

the computer is an old laptop, pentium 4m, 2.2 ghz. its got a new 80GB seagate 5400 rpm hd, and 768 of ddr ram. I'm running Road Runner on Windows XP Pro, using the Symplistique skin. Thanks to everybody who put their blood and sweat into RR and Symplistique, they were perfect for me.

the screen is a Lilliput EBY-701 LCD touchscreen with a VGA input. It's a tight fit, and the dash needs a little trimming.

http://www.digitalww.com/store/proddetail.asp?prod=EBY701

The computer actually sits underneath the driver side seat. its velcroed onto carpet. Actually more secure than i thought it would be, and the jack provides a non carpeted surface for the air vents. Seems to work pretty well.

[eTiMaGo]

man that's a clean, nice job, definitely an inspiration :wink:

As for the static hiss, it could be a lot of things. One thing I noticed when trying to play a PS2 into my head unit, is that the inverter can cause a lot of interference, this might be a problem, but it's more than likely a cabling problem somewhere... If you raise/lower the volume through the PC, does the hissing volume also increase/decrease? If it does not, then crank up the PC volume and lower the volume on the JVC deck, or on your aplifier if you use one.
Basically, you'll want to adjust your volume settings at each point so that your main amplification comes from the cleanest signal possible.

[qbunnie]

yeah, the static varies only with the amp gain, not from the lappy. Laptop volume cranked all the way, and I'm using the volume control from the deck, but unfortunately, its still noticeable (when its there). When the car's not running, i can turn the radio amp down to where the hiss goes away, but then, what's the point? I either hear static and music/directions while driving, or nothing at all, ya know? Anyhow, I've tried running the lappy on battery only for a little bit, but no luck. Hiss still present, so i don't think its power interference or alternator whine or anything... I just don't understand why it comes and goes. Maybe its time to save up for a new sound card...
Thanks for the help tho.
-QB

[Astroman]

Have you tried running the audio cables along a different route? Sometimes other electrical wires or components can cause interferance. There might be some kind of cable wrap or cable that has insulation designed to stop this. I know people who tried using IDE ribbon cables to mount a DVD drive and ran into such issues. I had my laptop in the back seat and ran audio through the aux input jack on my stock HU and didn't have any issues at all... Might try a different cable... And your setup looks great so far. I have a car DVD player that I thought of mounting in the glovebox like you did. Glad to know I can now. :thumbup:

[qbunnie]

Thanks to both astroman and etimago for the kind compliments

in response to astroman's suggestion, I haven't tried running a different route. I only have 6 feet of audio cable and I can't think of another route that will be less than 6 feet, unfortunately. Of course, I can always get more. It's a good suggestion that I will try out when I get the opportunity. I did choose the line-in aux input adapter since i was under the impression that line level RCA audio cables had less interference, although i could completely be making that up. The audio goes out from 3.5 mm to a cable that ends with RCA jacks.
Was your aux in RCA or 3.5 mm? I can get a 3.5 mm one, although i'm really hoping crutchfield let's me exchange it for the one i have.
Thanks again, to everyone.

[duck]

maybe buy longer AND shielded cables? does seem like interference or a loose connection.

i love the screen and the interface. wish i didn't already have a self-contained navigation unit or i'd do the same.

[slvryaris]

Roadrunner thats it! I was trying to think of the program name.

[eTiMaGo]

I never installed a proper carpc, but I did have a play around with the Centrafuse software (www.centrafuse.com) when it was still in beta, it's damn nice too. but pricey now :frown:

[AlphaFox]

I had a carputer at one time, I bought an inverter and it made the audio do that. I ended up just geting a PCMCIA SoundBlaster card, it sounded much better than the built in laptop sound quality!

[qbunnie]

Alphafox
while I am currently running off of an inverter, I am planning to hardwire the power into a DC-DC adapter soon. Do you think that would solve the problem? I don't think it will, since I have tried to run it off batteries only...
Anyhow, i'll start saving up for a laptop sound card now. thanks for your help.

[jaesusu]

woaw... that's was really nice job man!

the GPS with iGuidance 3 it's nice, but what hardware you are used?

[Yarii]

yeah, the static varies only with the amp gain, not from the lappy. Laptop volume cranked all the way...

If you're saying your laptop volume is set to maximum, turn that down as low as possible. As a general rule, the amping circuits on soundcards SUCK. My pc has a pretty high quality soundboard in it hooked up my 5.1 speaker setup; If i turn the PC volume output above about 40%, I get hissing, if I leave it low, I can crank my amp up to the max with very little deterioration of sound quality. Cable routing could also be a problem, but definately try turning the laptop down first. It could also be a corroded connection in the laptop. It wont hurt to spray some radioshack electrical contact cleaner in the audio jack (while the thing is powered off) and then plug your cable in and out a few times, help scrub the dirt off the contact points.

[qbunnie]

Well, i figured it out. It is my inverter. I didn't properly check the first time (I checked the hiss when i took the battery out, not when I turned the inverter off). Good call alphafox and etimago. I was planning to go to DC-DC power soon anyways. I also found out thanks to my friend that if I ground the outside ring of my adapter plug to car ground, i can make the hiss go away. He said it might make the sound in general funky, but it seemed to affect just the hiss, music sounded just fine. That's what I'll be doing for now, until I buy a DC-DC adapter.
Thanks to everybody for their help, and their compliments.
Yarii: the hiss actually only varies with my amp gain, not the volume setting on my laptop. I believe its a residual of the not exactly sinusoidal power the inverter supplies. thanks for the help tho!
jaesusu: All the hardware i used is listed in previous posts, in case you were wondering, the inverter is a xantrec 400plus. Also, some random switches and plugs were also used, mainly for the button to turn the laptop on and off, pictured with the handbrake.

[Mini Sumo]

what are the dimensions on you ts ? And did you get a new center bezel or cut the stock one ? I have a 7" TM-868 mounted on the flat part of the dash where the speedo is. My mb case is under the pass. seat.

Mini Sumo Was Here

[qbunnie]

H 4 1/2" x W 7 3/4" x D 1 3/8"

I trimmed the stock one. It's a very tight fit, but you can cut back the 'lip' of the back side of the bezel opening, so the touchscreen fits into it better. The height is the problem.

[AlphaFox]

try looking at mp3car.com for more info and good forums on carpcs. you still might want to look into another sound card, it made a big difference and you can do cool effects and make the sound field sound bigger.

[jetaimejsc]

where did you place your laptop?

[eTiMaGo]

this is where I put a PC in my car... :laugh:

[07typeS]

Damn Etimago, looks totally stock................. lol

[eTiMaGo]

perfect fit, too, very snug between the chair and dash :biggrin: