# Noob w/ Tablet - Connecting Multiple Channels to Tablet?



## Bunny (Apr 25, 2018)

Hey everyone, hopefully you can give me some insight on what the best course of action I should take to do what I'm wanting to do, which is be able to send audio from a tablet, to speakers. 

My car has the following:

Two Components w/ 2 "tweeters up front (More midrange than tweeter)" and Two Rear Components
4x additional 1" Tweeters in each door
2x Subs

If Ineed to get more technical on exactly what I have, we can do so, but I don't think it's neccessary for my issue.

The components are powered by a 4 channel amp, and so are the 1" tweeters, with another 4 channel. The subs are powered by a 2 Channel class D


Everything sounds pretty good for my ear, even without dedicated crossovers since the amps handle the audio tuning but I hate my poorly fitting cheap Android car stereo. 

I've been looking to install something along the lines of a Nexus 7 to begin, but possibly a Surface tablet running Android and Windows in the future as a car PC. 

Now, where my issues begin..

With my current deck, there are 5 available RCA jacks - FL, FR, RL, RR, and SUB. Each one of these RCAs is split with a ysplitter to accommodate for each speaker, which, if I've read things correctly online, is already not ideal but it's the only way I can connect the amps to the stereo (Or am I supposed to be using dedicated crossovers for this?)

With most tablet installs, it looks like most people purchase a USB DAC, but these DACS I'm seeing only have a F/R RCA or 3.5mm output. There's no RCA for a sub or anything else. Do I just split the outputs repeatedly to accommodate my wiring, do I use an audio processor, etc.? Repeatedly splitting those two plugs doesn't seem ideal, or if its an aux, do I just split the aux into 4 channels, have those 4 channels go to their respective inputs on a crossover e.g. front in and rear inputs, and then have the outputs go back to the amps? I'm probably really overthinking this.

TLDR: What's the best way to connect my 10 channels to a tablet? I'm probably leaving out some important information...it's late where I am, but I'll be sure to get back with any information you need to lend me a hand. I'm still very much a newbie at audio so I'm sure I'm overlooking basic things... not to mention being a broke high school student, I can barely afford some of these toys, so I try to make do with what I have and on 
local marketplaces/thrift stores haha.

Thanks!


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## SPLEclipse (Aug 17, 2012)

It depends on if the deck is handling any crossover duties or if you use it to control the sub volume or anything else related to audio control. If you don't need the tablet to handle any of these functions you can just use the DAC's single output and split it as many times as you need. There will be no real loss in quality or signal level as the input impedance on most amps is 10kohm or even higher and the relatively low output impedance of the DAC meas you might only drop a tenth of a volt of signal potential. This does, however, bring up the point that most consumer gear (including DACs) will have a lower signal level than car-audio specific headunits. You may have to adjust the gain structure on your amps to accommodate this, although most of the Android headunits I've seen don't have a very high line-out voltage anyway.

Again I have to point out that you loose any tuning control when you're splitting like this, so no fading or balance, no sub level volume, no crossover or anything that needs to affect individual speakers from the tablet. Global EQ and global volume will still work just fine.


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## Bunny (Apr 25, 2018)

Gotcha, that's what I wanted to hear ^^.

If I made any tweaks to how things sound from an external device, usually I do that via my phone using Viper4Android or something and then I just Bluetooth or aux to my stereo, I rarely use the stereo's built-in faders and stuff either so I'm hoping that not having it in the tablet would affect me much.

So just to recap, basically all the tablet would be for is just to send out an audio signal. Crossovers and the amps handle everything else, including tuning? I can attach a (provided it existed) a 3.5mm to 10+ output without issue?

Thanks again ^^


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## gijoe (Mar 25, 2008)

What are your goals for your system. Without being rude, you have WAY too many tweeters if you want any hope of good sound quality. It sounds to me like you have a plan in mind that you're running with, but the final result will be much better if you simplify things. You've got far too many channels, and far too many speakers. You will not have enough control with any DSP available to make your plan work. 

Again, what are your goals? Sound quality, SPL, show?


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## SPLEclipse (Aug 17, 2012)

Bunny said:


> Gotcha, that's what I wanted to hear ^^.
> 
> If I made any tweaks to how things sound from an external device, usually I do that via my phone using Viper4Android or something and then I just Bluetooth or aux to my stereo, I rarely use the stereo's built-in faders and stuff either so I'm hoping that not having it in the tablet would affect me much.
> 
> ...


Everything affecting the audio will need to be handled by the amps or any external crossovers. You'd basically leave everything like you have it now since you're not using the android deck for anything besides a simple signal source. Something I forgot to mention earlier - it's very likely the external DAC with the tablet will be of much higher quality than the one you currently have so you can expect things to sound perhaps a little more on the brighter/clearer side. I noticed a big difference when I went from using my old Nexus7's 3.5mm out to using an external DAC (Behringer uca202). Splitting to 10 outputs is not a problem. Just adjust your amp gains accordingly if needed. 

I do agree with gijoe that you could probably simplify your system to a large degree not only to make things easier but also sound better, but it's not my place to judge your preferences. I mean I'm on a primarily SQ forum with SPL in my username so I get it, lol.


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