# carPC/tablet car interface?



## fuzzysig (Feb 4, 2010)

im still a bit confused about how to interface the carPC/tablet with the car system

the amp and volume control etc.


is there a din sized control panel that has a built in preamp or DAC that has outputs for a car amplifier or is it still kinda lacking in that area as it was in 2006 when it first started?


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## BlueGhost (Jul 28, 2014)

I just replaced my carpc with my Galaxy S4. I've done volume control a few different ways over the years.

For my original set up I used a Kicker 3 channel amp and a JL audio CL-RLC. It's a line driver with a built in remote volume control. I was running from my USB DAC to the CL-RLC into the amp. 

Then I switched amps to a JL Audio XD700/5 and bought the remote level controller for the amp. The XD amps have a switch that allows for volume control of all channels or just the sub channel. I ran RCAs from the USB DAC directly into amp and used the volume knob to control all channels. This was a step up over my original set up, mainly because it was a better quality amp and I went active with my components at the same time.

I just installed a PPI DSP-88R. It comes with a small controller for switching inputs, selecting eq presets, and adjusting volume. I'm using the optical input with an APT-X Bluetooth adapter and streaming from my phone. I also have an HD radio tuner running to the AUX input. So I basically replaced the carpc and USB DAC with my phone and the DSP-88R.

I haven't had time to do any real tuning with the DSP-88R. I did to listen to a few samples after getting it installed, so far it sounding better than any of the other configurations. I'm sure it will only get better once I do some tuning.


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## NealfromNZ (Sep 3, 2013)

Depending on car pc software you can get steering wheel volume control interfaces that plug into the pc via USB. Software such as riderunner for windows has many community written interfaces and normal just require a USB to car bus interface.

Otherwise , as blueghost pointed out. Many processors have a remote volume and source control unit.


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## fuzzysig (Feb 4, 2010)

nice I didn't see that one when I was looking for preamp I saw the audiocontrol etc.

I actually emailed audiocontrol about 2 years ago to see if they would think about making an interface for tablet/carPC but there was no response. I figure they don't care...


im assuming theres no true digital connection to an amp yet?

like a usb or hdmi directly to an amp from a source and amp having onboard dac to minimize the noise from running RCAs?


my thinking is if im gonna do the computer/tablet system I might as well eliminate the RCAs

if there was an amp with onboard DAC and a wired controller like the PPI I would be allover that sht.
but so far have not found one.

I mean I could just solder shielded cables from the external USB dac right into the amp and run a digital cable across the car.but that would be crazy( or is it?)


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## fuzzysig (Feb 4, 2010)

kinda like this but for the car and cheaper
Peachtree Audio Nova (Rosewood) Stereo integrated amplifier with built-in DAC at Crutchfield.com


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## fuzzysig (Feb 4, 2010)

every time I look through the new gadgets I feel like car audio industry is like a retarded kid in class. everyone just avoids it until theres nowhere to look

were always the last to get the up to date tech
it was like that with cd,then mp3 support then usb now flac and starting to be with dacs and usb amps. we probably gonna get them by 2020 or so. when cars wont even have headunits anymore. 

theres probably 100s of usb DACs and even usb amps with built in DACs with Bluetooth and all kinds of sht.

but I haven't found a single unit for car audio. it is so lame that we always get overlooked until its like 5 years into it. companies be like oh wait we need to make something for these car audio guys *cough cough*

rant* bitching etc. spending days in search of something that should be available already but its not. I mean all they really have to do is change the power supply unit from 110/24 volt to 12 volt and make it din size. not that hard...


like HIFIDIY they have a perfect usb dac with volume control and display and usb input. that takes 12 volts input.. great.
but no eq and only 2 speaker outputs.
which means still analog to DSP or amp

then there is a usb amp with integrated DAC and again only 2 channel output
SMSL Q5 True Digital Audio Amplifier Remote USB Fiber Coaxial Input 192kHz 50W 2 | eBay


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## REGULARCAB (Sep 26, 2013)

fuzzysig said:


> every time I look through the new gadgets I feel like car audio industry is like a retarded kid in class. everyone just avoids it until theres nowhere to look
> 
> were always the last to get the up to date tech
> it was like that with cd,then mp3 support then usb now flac and starting to be with dacs and usb amps. we probably gonna get them by 2020 or so. when cars wont even have headunits anymore.
> ...


You forget that the guys like us that want to diy don't even make up .1% of the market. The vast vast majority of people are happy if the can hook up their phone to their stock headunit.


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## fuzzysig (Feb 4, 2010)

yea but so is the home audio DIY guys.
and look how much crap they have available.

just search ebay for usb dac and usb amplifier ive been browsing for an hour and still not done.

I found a lot of units that I could possibly use
but they all missing one or two features

Im thinking best way would be to use a car pc/tablet. and a usb dac mounted right on the amp and very short rca cables 
I have a kenwood excelon kac-x4r amp that has an onboard dsp so I can split the channels through that and output to the sub amp as well. that's like the best solution I can come up with.


ideally if I could find a usb amplifier that has at least 4 channel output with onboard dac, crossover and even basic eq I would be happy.

I like minimalistic setups with as little components as possible that's why im obsessing with all this sht.
if I didn't care I would just stuff a few boxes around the car and be ok with it

but I do like that PPI dsp thing that blue ghost mentioned I might end up just getting that


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## fuzzysig (Feb 4, 2010)

we just had a tesla in the shop that's why I got obsessed with this tablet thing again
I put that to rest about 2 years ago when I looked and looked and didn't find what I wanted so I gave it some more time hoping something will be made...

and now that I cracked my digitizer on the indash its like 100 bucks to buy a replacement one when I paid 350 for the whole thing I think im gonna just not fix it and sell it on ebay lol


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## ZeblodS (Nov 4, 2009)

fuzzysig said:


> im still a bit confused about how to interface the carPC/tablet with the car system
> 
> the amp and volume control etc.
> 
> ...


Or you can build your own amp/volume control.

I have a car PC with Windows 7 and use the optical spdif to send the music to a DSP based on miniDSP boards which have an external volume control using a variable resistor.
My subwoofer amplifier also have an external volume control using a variable resistor.

So I build an electronic board to manage my whole audio setup :


I can manage the general and subwoofer volume, and the remote control of each parts (PC, DSP, all three amps) aparts.
But I also have a thermostat with fan control (in the trunk), a voltmeter (battery voltage), speed input (ABS signal input -> volume goes up with speed to compensate the road/air sound), USB HUB and PC screen power management, electric antenna remote, etc.
Going full DIY enable you to do whatever you want!


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## t3sn4f2 (Jan 3, 2007)

I think the best option is to get a pioneer 80PRS and look at it as a USB DAC/multi-sourced preamp. Then mount it near the amps or processor and run a long USB cable to the rear. That'll give you a very high quality car audio specific DAC (ie plug and play noise free power supply), high quality analog master volume control, HD radio, speaker level AUX in to keep an OEM head, steering wheel controls, media navigation from the device, etc. All for less than a high quality regulated/isolated power supply for the DAC if you went with another option. I plan to do this one day, but will likely run the unit in fixed out mode and do master volume control from the processor or amps. For better resolution going to the DSP. And discretely mount a future release of an iPod tethered to my iPhone.

There might be better option out there now, but I think this is the only one that is easy to implement and will for for everyone right out the box. No weird complications to deal with.


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## 1fishman (Dec 22, 2012)

BlueGhost said:


> I just replaced my carpc with my Galaxy S4. I've done volume control a few different ways over the years.
> 
> For my original set up I used a Kicker 3 channel amp and a JL audio CL-RLC. It's a line driver with a built in remote volume control. I was running from my USB DAC to the CL-RLC into the amp.
> 
> ...


Which APT-X Bluetooth adapter did you use? Haven't seen any with a optical out.


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## RoyAlpine (Aug 31, 2008)

Cheap and little expensive.


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## BlueGhost (Jul 28, 2014)

I'm using this one from monoprice


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## eviling (Apr 14, 2010)

to go from digital to anilog you need a dac = digital audio converter, a sound card is a "dac" it turns a digital signal into analog or more digital signals with processing done depending on the complexity of the board. so you want a dac. 

for the rasbery pi board, theirs an expansion dac board. some android boards have optic out, thats easy to go to allota processors.


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## fuzzysig (Feb 4, 2010)

are you talking about me or other replies?
I said that in first post. that's what im looking for.
to eliminate rca cables and find an amp that has usb or at least hdmi input or optical
if not then ive been checking the components for a DIY amp with built in dac.

which I found but only in 2 channel


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## Ultimateherts (Nov 13, 2006)

fuzzysig said:


> are you talking about me or other replies?
> I said that in first post. that's what im looking for.
> to eliminate rca cables and find an amp that has usb or at least hdmi input or optical
> if not then ive been checking the components for a DIY amp with built in dac.
> ...


The Old school Alpine Theater amps are meant for surround sound in a car, but offer a 5 channel and optical in!!!

http://www.crutchfield.com/S-VIueOPDk5KE/p_500MRAD550/Alpine-MRA-D550.html


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## fuzzysig (Feb 4, 2010)

yea I know about that one. but "fcuk alpine" they re like apple. always "require alpine to use with alpine etc" the optical input is alpine specific from what I read in the specs.

i might just pick up a tablet and one of those usb amps with internal dac and be done with it.i just like simple now. back in the day i made complicated setups now i spend more time trying to make a setup simple but effective and no spaghetti running back and forth behind panels.


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