Tablet Head Unit - BrainStorm

So I figured I would get some info here, hoping some heavy stereo gurus exist among us, which Im sure there is.

Im planning on installing a Nexus 7 (not concrete on that brand) in the dash as the head unit, I can do most but need help with logistics and some of the devices to accomplish it.

#1
Main issue is audio signal. How to run audio (digital form) from tablet to 4 channel amp (which will be RCA in) with good quality. I prefer bluetooth (since its a true digital) but not opposed to wire, if anyone knows a USB attachment that works with Android devices. I do not want to run AUX 3.5mm, not a good quality, in my opinion. I want 2-3 RCA's so I can have a true 4 channel amp running as well as dedicated subwoofer channel.

Options:
Tablet > Bluetooth >> ??device w/ 2-3 RCA output?? > Amp
or
Tablet > USB ??device w/ 2-3 RCA output?? > Amp


#2
Control of volume or EQ. I know I could run a audio processor to handle EQ for me, but don't feel like dropping 150-400 bucks for a decent processor to accomplish this. EQ could be handled by the Amp, and Im not set on brands yet, so feel free to make a recommendation, premium quality no competition level. I want to keep my price less than $500 out the door.

Also how do I control volume with ease? Gain nob attached to the dash just seems a little tacky or ghetto. I thought about solving EQ and Volume with 1/2 din EQ and mount it right under the tablet. Havent seen many 1/2 din EQ's anymore


#3
Power, here is were some things get tricky. I can either setup a remote button to trigger the power button on the tablet. Ideally, I want the tablet to auto shutoff (screen locked) when the car shuts off. I havent messed with NFC's before, and technically dont know the limitations of them yet. I wonder if powered NFC device attached to power from ignition on the car could provide the source of signal for the tablet. When its powered on, it allows the tablet screen to stay on (as if in car dock mode) and once the device shuts off, the tablet screen will auto time out. All of which could be programmed with a profile manage on the tablet as to rules or conditions (if than).



Give me some ideas, if you know of some devices that might help me, please list it. Still brain storming. I know the majority of this is possible, seen many do it. Im just trying to take it to a level of automatism.

 

I will eventually figure this out, its possible, just working out which devices and to use, and trying to keep the cost down. Technically if you have 400-600 bucks just go buy some of these audio processors, they have everything you need already.

 

I'd love to see how you do this. I have an 05 LGT also and the integrated head unit is somewhat holding me up.

 

Solution for tablet side, as far as software goes:
http://www.autosenseapp.com/phpBB3/

Also for those who want to mirror screens, here is another solution:
http://customgadz.com/mimicsx2/9-ul...ehicles-with-factory-touchscreen-display.html

Digital Processor/Equalizer/RCAs/Volume Control Knob
http://www.onlinecarstereo.com/CarAudio/p_21807_Soundstream_DIGI-Q.aspx

This was the greatest find, a EQ that didnt look retarted, and had all the features needed. Ill post a picture of the schematic soon.

 

Another Equalizer:
http://www.onlinecarstereo.com/CarAudio/p_39038_Earthquake_EQ-4000BT.aspx

This one would be great considering the bluetooth, but dont like that its only 4 bands.

I really wish I could find a EQ that can be controlled via the tablet, or one that is touch/feather buttons. Not a fan of knobs....

 

If you can find a tablet you like with USB input you can run an external DAC, but it has a knob :rofl:.
-->DAC <--

Or even better get your Raspberry Pi on with a "carberry" board, and build exactly what you want from the ground up.

 

SUCCESS!!!! Only took me 6 hrs of researching, lol

I was able to come up with a solution that will:

1. Fully integrate Tablet in dash (with NO headunit)
2. Seamlessly connect all devices
3. Auto shut off, and turn on
4. True 4 channel audio (High Quality)

I tried to keep it as simple as possible and as versatile as possible, never know if you want to change your configuration or something better comes along.

I decided to go with a Samsung Galaxy Tab 4, only because of price and easy ability to plug multiple USB devices to it without having to modify the ROM or kernel. If you have a Nexus 7 (or any android devices for that matter) you can do this exactly the same, just one extra step, search for how to make Nexus 7 a OTG/USB-host. If your not savy with rooting you can just buy Nexus Media Importer. Does it all for you.

Items youll need:

1. Tablet (obvious) $150.00
2. Bluetooth 4.0 with Optical - output $45
3. 5< Band EQ w/ Optical in and RCA out (3 RCA pair) $55.00
4. Powered USB hub $15.00
5. OTG adapter $7.00
6. Media/Volume Controller (2 choices: Griffin PowerMate, Vmeter Strip) $45.00 or $15.00
7. 4-Channel Amp of your liking (or just roll it all into a 5-Ch.) $140.00
8. ODBii Bluetooth adapter $15.00 (torque compatible)

Total: $472.00

Created a Amazon list of the ones I will be using.
http://amzn.com/w/3R4P4LW0R5QLY

Software side, most can be controlled with Tasker on the auto shut off/on. If you tie all the power back into the same power the Radio was running off of, this will keep your tablet operating when the key is on Accessory or On. Your profile in tasker you create will tell the tablet to never time the screen out while charge is active, or bluetooth is connected (since the bluetooth adapter is powered by the same source) and to lock the screen when it is not on charge, maybe even put it in Ultra-Power saving mode, so you dont ever have to worry about it dying on you in the dash.

Lots of extra USB connections, powered and one extra to plug into tablet if you decided to go buy big flash drive to attach to it for media storage.

Schematics


The only thing Im not 100% sure on is how I am going to mount the tablet. I found a company that makes some general ones (if you dont feel like fabricating) but Ill have to hunt that page down again.

Im hoping to start on the this project come end of this month, waiting for a few more paychecks and sell a couple things.

Hope this helps someone

 

#1 I created a fiberglass enclosure to support an ipad in a friends 77 caprice/Monte Carlo (sorry I don't know my american cars) to use as a head unit. We ended up using a 3.5mm jack and 2 y splitters (one pos, one neg) to go to two amps. One amp was a four channel the other was a 2 channel for subs. Alpine PDX amps, Alpine type R components and coaxial, Alpine type x subs. Sound quality is great. Much better than we anticipated because it was through a jack.

#2
He purchased an equalizer app from the apple store (if that what its called? I have android) and I also installed and old school rockford eq mounted in his glove box. A bit of a pain to reach over everytime but how often will he really touch it.


#3
Youll have to use the power settings in the menu. When the car shuts off the device will "auto turn on" because your power source is "disconnected." When ever i get around to it I will install my tab in my car. My tablet is rooted (Galaxy with CM 12 lollipop firmware, waiting to see if SlimRom can produce a better OS) and I installed the LG's knock knock feature (tap the screen two times to auto time out/turn on. Also I have custom settings to put everything into auto block/airplane mode from 2am-7am so its not in use while I'm sleep.

 

When you do the install I'd love to check it out sometime, looks promising!

 

I have that connector for mine and that is the route im going.

Home Depot sells fiberglass. Ill try to get some pics this weekend of the one I did. It was my first fiberglass job. Had to do it two times as the first time it was too soft and fingerprint marks would show up on it lol. Its been 3 years and his enclosure still holding up strong with no chips and cracks. Took two weekends to do it.

 

if you have ever patched a hole in a wall you can definitely lay fiberglass.

 

Question, did you even read any of my posts? 3.5mm is only a stereo output so there is only Left and Right (2 channels) coming from the tablet. Defeats the purpose of the build in my opinion, you have a full digital source at your finger tips, use it. Majority of Amps (especially 4-channel) will up-scale and fill in the gaps, which is why it sounds full to you. Not horrible, just not what I want.

The above build is digital all the way up to the EQ, allowing the output for each channel, making it 5.1 DTS essentially.

Fiberglass wont be an issue, but would rather keep it as stock as possible. I have no need to pull the tablet out once I get it in place, so it will be a fixed mount the the back of the current dash kit. Plus for LGT we got the short end of the stick, in order to put in a aftermarket head unit, you gotta spend a good 350-400 bucks for the dash kit. No way in hell am I cutting that thing up. Fiberglass center dash really isnt my thing anyway, looks great for show.

The mount will replace (possible use some) the radio mounts. So it will mount similar to a regular radio, then placing the trim or bezel over the radio to frame it. The trick is to get the mount depth just right so when i put the bezel on Im not smashing the tablet or leaving a huge gap between the two.

You know it man, if you hold out till this time next year Ill come help you with it when I move back. Ill post up full detail pictures when I start the process. Just ordered some of the parts today

 

I did read your post. I was just stating the route I had made. I never seen a connector for the Nexus 7 like the Samsung and Apple ones for this application which is why i referred to the 3.5 jack method with splitters.

I wouldnt recommend cutting your dash/console but instead fab a mount/bracket that utilizes the stock radio mount location and create a fiberglass holder. The one i made has a dip where you can slide your finger to remove the tablet when not in use. Also, he had a custom dash and interior so we painted the fiber glass a matte blue so it blended with the leather dash. It was actually spot on in color.

If you go the full 5.1 where will your 5th speaker be? In the dash up front in the center or in the rear deck? if up front would you use a 5" mid bass (mini sub) or tweeter? in the rear an 8" mid bass or a 6.5" coaxial?

edit: i just googled your radio/ console area. That is one crazy looking area. That is something else. I wonder if wrx console could swap in its place???

 

The dash unfortunately can't be swapped. People have tried many different routes to accomplish this, just doesn't work out. Radio circuit board is integrated into the dual HVAC system (dumb Subaru decision).

I'm not going to be running a fifth speaker, "essentially" it's 5.1 DTS meaning it's a true multichannel audio. The Nexus 7 can be connected exactly the same via audio, only difference is the USB connection, it will need the USB host connection adapter, I believe magma makes it.

 

No lie, I was just looking for another knob to use.... the powermate is great but from my findings online, it isnt really compatible with android. It can be done, but you have to mess with the kernel.

 

Update on the headunit...

I have installed just about everything. I have had to make some alterations to the original plan, but all is working well. The new hardware to make the rest possible should be in soon.

My dash (JDM aftermarket) made up of mounting bracket, doubledin bezel and HVAC controls. Then all is held snug by two runner bezels that run the length of the console. So I decided to use the sandwich method.



Removed all brackets from the doubledin bezel and fabricated 2 of my own out of 3/4" x 3/4" angle aluminum. Which have enough pressure to hold the tablet in place but yet is still removeable.

Due to the hazards switch, I was left with only one way to orient the tablet, with the menu button and back button on the left.

My first attempt at mounting the brackets failed, just placed epoxy on the bottom of it and it broke off the min it flexed. So second go round, I floated the area with epoxy to make it more rigid.


Left hand side has charger port so i cut a notch out to allow for the charger cable connection.


Right side, I didnt need to notch. If you plan on using the headphone jack, you will need to. I connect via bluetooth.

Next issue was the power button, and volume up/down buttons faced down. So everytime I pushed the tablet into place it would depress one or all the buttons.


So I marked the area on the bezle and then placed it on top of the HVAC contols and notched out a area to allow room for them to sit.


Notched area.


Attached some MDF into the mounting bracket for the tablet to rest against once the bezel was snapped into place.




The MDF also allows room to mount various other devices if needed (equalizer, USB charger hub, Bluetooth unit, etc) I opt'd out of the equalizer, just because my amplifer has built in EQ and sound processor which sounded good enough for me.


Its a night pic, but its in and it looks beautiful...!!!!

Ill post up more pics of the amp, the amp mount, and some other wiring tricks I did, tomorrow.

 

So when do you want to come do this to my car? lol!

 

I told ya Ben, I would gladly help ya with it. Ill trade ya my services for your Blouch Turbo..... lol

Seriously though, when I am back in town. Ill help you with it. Start shopping now for the tablet you want, and 5 channel (or 4channel) amp of your liking.

 

Whats wrong with you Matt.... I thought you were a Android lover, did you go over to the darkside....? For the price and performance Galaxy Tab 4 is hard to beat.

 

I have a blown 20g that I'd be happy to let you take! Now the Dom 1.5 on the other hand... That's not going anywhere.

 

We need to talk Ben....

 

Here is some daylight pictures, as well as the amp and rack.

The I still need to make some adjustments to the bracket if you can tell. The bezel is shifted to the right as well as the HVAC unit, causing the side bezels to bind on the double din bezel, slightly bowing in in the center. First on my list to address.


Also have to figure out why torque is not picking up all the info from my ECU. I have verified on LGT forums that all these dials should have data. Some will be estimations and others will be raw.


The bowing is pretty obvious here.

Amp and amp-rack were difficult to figure out a mount for. I have seen many do the in the spare tire hole, but to me that just spells disaster (overeating). Because of the size of the amp (length) I couldnt mount it to the back of the seat and I wasnt about to try and make a massive sub box that stretched along the side of the trunk. So I inverted it and mounted it to the deck lid.


Challenge was clearing the trunk torsion bars and center seat belt reel.


Ended up serving a double purpose to hide all the extra wires.



Next post Ill show you how I setup everything behind the tablet to allow for full integration, and future upgrades.

 

Installed some of the guts and back bone for the tablet today, still waiting on more to come in. Most should be here tomorrow.

Mounted the USB powered hub and Bluetooth module to the bottom side of the MDF that supports the tablet.


Always make sure you run a inline fuse or a fuse somewhere for whatever new stuff you put in. Bad mojo

Also installed a shorter ground for all these units. Want to make sure they choose the path of least resistance rather than my RCA cables. Ground block you can pick up from home depot for $4


Wire loom is your friend, keeps things nice and neat, but also sheilds wires (plus electrical tape of course).



Something to be mindful of when you are running your wires, never run power wires and signal wires with each other. Here, signal exits on the left and power exits right. This will help cut down on static pickup on your lines. I do have mine zipped together at one point, but they are not running parallel.

I have the volume nob ran, but didnt take pictures. Will post it tomorrow.