tablet for head console???

[Sick5]

has anyone seen or have a thread with a tablet or even a phone as your main head unit...
im liking this idea.. just dont know in what direction i want to go

[MadManAndrew]

Every build I've seen where they did they didn't actually use the tablet as a head unit. They used an iPod capable head unit, moved the head unit elsewhere (sometimes hide it so it does look like the tablet is the head unit), then integrated the iPad (or other tablet) into the dash where the head unit used to be. The ipod cable would plug into the iPad behind the dash and run to a rear usb input on the head unit.
Posted via Mobile Device

[jimmydean]

I will be using a 7" tablet for mine. Audio, video, navigation, remote start, power windows/doors, GPS locator and alarm are all ran off it. Next is to develop an app to control my air ride, then I will be set.

[Sick5]

Originally Posted by jimmydean

I will be using a 7" tablet for mine. Audio, video, navigation, remote start, power windows/doors, GPS locator and alarm are all ran off it. Next is to develop an app to control my air ride, then I will be set.

WOW do you just run you iPad
STRaight to the amp?

[hairlesshobo]

There is no reason why you cant run the ipod or tablet straight to the amp(s). There are a couple things I would keep an eye out for.

First, make sure that your tablet of choice has volumes controls that increase/decrease in small steps. If your tablet/phone only has 10-15 steps of volume then with a powerful amp, the volumes will tend to jump drastically and be hard to tweak.

Second, depending on the music app on the tablet, you will likely find yourself without a software equalizer. Unless you find the pperfect speakers, you will want to install a hardware equalizer.

Third, if you are running multiple amps, you will most likely need at least a 2 or 3 channel crossover. Some amps have this built on, some do not. If you have amps without crossovers, you will want to purchase either an active crossover, or passive in line crossovers for your speakers.

With all of this said, it is definitely possible to run a tablet or phone without a head unit as long as it is setup accordingly. I have done this before in the past when I had a head unit with no line in.

[jimmydean]

Originally Posted by Sick5

WOW do you just run you iPad
STRaight to the amp?

Android tablet run to a line driver/crossover then to the amps. You could go headphone to RCA straight to the amp, but the signal from the headphone jack is weak. A line driver to amplify the headphone signal is the way to go.

[hairlesshobo]

Originally Posted by jimmydean

Android tablet run to a line driver/crossover then to the amps. You could go headphone to RCA straight to the amp, but the signal from the headphone jack is weak. A line driver to amplify the headphone signal is the way to go.

For conversation sake, I have a question about the line driver portion of your setup. Please read the whole thing first before you think that I am trying to say you are wrong because I am not - I am merely curious.

You are sort of correct when you say that the headphone output is week, at least in relation to a lot of modern head units. In comparison to standard line level, the headphone jack is usually right on par (with the exception of some really cheap players with weak internal amps). Headphone output on these devices is typically ~1 volt RMS, give or take a few hundred millivolts. The only reason that it may seem that the headphone output is weak in an automotive environment is because a lot of head units nowadays have a 2v, 4v, or a lot of times 6v "line" out. While this is a nice feature for sake of minimizing noise in the signal lines, it's actually much higher output than what a real line level is.

The reason that the 6v line level works is because a lot of amps, crossovers, EQs, etc in the automotive world also support it. This variation in "line level" voltages is the main reason that the gain control on an amp exists. The gain control allows you to adjust each amp individually to match with fellow amps, as well as reduce clipping. Remember, gain is not volume control. For example, if you have an amp that is capable of up to 6v line input, and you are using a 6v head unit, if you turn the gain all the way up on the amp, it may "seem" louder, but in all actuality you are just over driving the input and causing the amp to clip.

I say all this to say that with almost all amps and automotive audio equipment, they are prepared to accept a signal input of between 1v-6v for sake of compatibility with all head units. With that in mind, almost all equipment if properly calibrated and tuned, will work just fine with a "lower" 1v input. By properly calibrated I mainly mean that the gain on all amplifiers and crossovers are set correctly.

I am curious to know what gear you are running in particular that wouldn't work to its full potential without including a line driver with the rest of the system.

If there is something here that I am missing or forgetting, please tell me because I don't want to come off as an jack@$$.

[hairlesshobo]

Originally Posted by jimmydean

I will be using a 7" tablet for mine. Audio, video, navigation, remote start, power windows/doors, GPS locator and alarm are all ran off it. Next is to develop an app to control my air ride, then I will be set.

Sounds very similar to the idea that I have been bouncing around with for quite some time. The biggest difference is that I plan to use a 7" touch screen VGA monitor connected to a custom "Carputer." I will be running Linux on the carputer with the ability to do just about everything short of having coffee ready when I get in the truck in the morning.

I would love to see your progress as you set this up!

[kikkegek]

Subscribing, this could get interesting.

[jimmydean]

Originally Posted by hairlesshobo

For conversation sake, I have a question about the line driver portion of your setup. Please read the whole thing first before you think that I am trying to say you are wrong because I am not - I am merely curious.

You are sort of correct when you say that the headphone output is week, at least in relation to a lot of modern head units. In comparison to standard line level, the headphone jack is usually right on par (with the exception of some really cheap players with weak internal amps). Headphone output on these devices is typically ~1 volt RMS, give or take a few hundred millivolts. The only reason that it may seem that the headphone output is weak in an automotive environment is because a lot of head units nowadays have a 2v, 4v, or a lot of times 6v "line" out. While this is a nice feature for sake of minimizing noise in the signal lines, it's actually much higher output than what a real line level is.

The reason that the 6v line level works is because a lot of amps, crossovers, EQs, etc in the automotive world also support it. This variation in "line level" voltages is the main reason that the gain control on an amp exists. The gain control allows you to adjust each amp individually to match with fellow amps, as well as reduce clipping. Remember, gain is not volume control. For example, if you have an amp that is capable of up to 6v line input, and you are using a 6v head unit, if you turn the gain all the way up on the amp, it may "seem" louder, but in all actuality you are just over driving the input and causing the amp to clip.

I say all this to say that with almost all amps and automotive audio equipment, they are prepared to accept a signal input of between 1v-6v for sake of compatibility with all head units. With that in mind, almost all equipment if properly calibrated and tuned, will work just fine with a "lower" 1v input. By properly calibrated I mainly mean that the gain on all amplifiers and crossovers are set correctly.

I am curious to know what gear you are running in particular that wouldn't work to its full potential without including a line driver with the rest of the system.

If there is something here that I am missing or forgetting, please tell me because I don't want to come off as an jack@$$.

I have no idea what you are talking about.

Here is what I am running and why. You can run whatever you want in your truck.

My MP3 player or tablet, or any other "source" I use for content has a standard headphone jack out. It's a stereo jack, left/right only and has minimal source voltage. Rather than take a low voltage stereo only signal straight into the amps are two fold:

1. I have 2 amps (bass amp, mid/high amp) rather than split a stereo signal straight into the amps, I will first split the signal at the crossover allowing me to dial in the signal (pre-amp).

2. The input signal is now split and dialed pre-amp AND increased to a reasonable voltage level.

So CAN I go headphone to 4 way RCA into 2 amps? Yes. I can and have done so in the past. Am I going to this time? No.

Why? Because I want the ability to pre-amp filter. I would do this even if I was running a standard head unit, not just because I am using a headphone jack.

Make sense?

[jimmydean]

The crossovers built into most amps are ok, but for efficiency sake, I like to pre-amp filter so the amp isn't concerned with what it doesn't need to be concerned about.

So to answer the question (that was wicked buried in your post):

I am curious to know what gear you are running in particular that wouldn't work to its full potential without including a line driver with the rest of the system.

Any time you are putting a full range signal into an amp the is not going to amplify the full range, it is not working to its full potential. The line driver is only a nice feature, it's the pre-amp filtering and splitting of the stereo signal that I am after.

[jimmydean]

And the reason I went with the tablet rather than a standard linux box is I just don't need the horsepower. I have a linux netbook I can sync with the tablet if I want to, but I just don't need a full box.

Besides, its a LOT easier to mount a tablet.

[hairlesshobo]

Originally Posted by jimmydean

The crossovers built into most amps are ok, but for efficiency sake, I like to pre-amp filter so the amp isn't concerned with what it doesn't need to be concerned about.

So to answer the question (that was wicked buried in your post):


Any time you are putting a full range signal into an amp the is not going to amplify the full range, it is not working to its full potential. The line driver is only a nice feature, it's the pre-amp filtering and splitting of the stereo signal that I am after.

Yeah, sorry I tend to ramble when it comes to talking audio.

I see now why you chose to go the line driver route. I don't blame you at all, it definitely makes things more consistent. Plus using it as an active splitter helps keep from losing signal due to passive splitting. I've never thought of it that way. Thanks for the eye opener.

Originally Posted by jimmydean

And the reason I went with the tablet rather than a standard linux box is I just don't need the horsepower. I have a linux netbook I can sync with the tablet if I want to, but I just don't need a full box.

Besides, its a LOT easier to mount a tablet.

Yeah mounting is one concern of mine. I know where I'm gonna mount the screen, but I'm already starting to run out of space behind the seat to mount amps. I'm gonna have to come up with something clever to mount the car PC in there as well.

[jimmydean]

I don't have room under my seats since I have them dropped all the way down for driving anyway, but if you use the right form factor, you can put it under the dash. I was going to mount mine above the glove box with access from inside the box top.

The 7" tablet just fits perfect. I just haven't settled on one yet. The Kindle Fire is a strong contender, but a quad core is in the works. Whatever it is, it will be rooted and wiped clean first.

[jimmydean]

My highs all have passive filters as well as the active filter. Passive filters are nice, but they also add to overhead. But if you can filter the highs out of the signal pre-amp, then the amp is left to do it's thing. You can further filter using the amp, and filter further using a passive setup. The nice thing about active filters is they are usually variable vs. a passive filter.

But my tunes sound good when it's all said and done.

[hairlesshobo]

Originally Posted by jimmydean

My highs all have passive filters as well as the active filter. Passive filters are nice, but they also add to overhead. But if you can filter the highs out of the signal pre-amp, then the amp is left to do it's thing. You can further filter using the amp, and filter further using a passive setup. The nice thing about active filters is they are usually variable vs. a passive filter.

But my tunes sound good when it's all said and done.

Yeah I'm with you on that. It's always best to filter what you can BEFORE it hits the amp, so that as little of the amp is wasted on unwanted frequencies as possible. Then if you need a little further tweaking, inline passive filters are indeed nice. Plus, if you are working on a mostly factory system, passive filters make life much easier!

[Pop's C-10]

subs for good info..

[jimmydean]

When I first started looking at a tablet or Linux front end, I really thought there would be something cooler than RCA interfaces, but it doesn't seem like HDMI is used in car audio.

Granted I am far from heavy into what's out there, but I haven't seen much.

[hairlesshobo]

Originally Posted by Pop's C-10

subs for good info..

Huh?

Originally Posted by jimmydean

When I first started looking at a tablet or Linux front end, I really thought there would be something cooler than RCA interfaces, but it doesn't seem like HDMI is used in car audio.

Granted I am far from heavy into what's out there, but I haven't seen much.

I haven't heard of anything nicer than RCA either. Even if they came out with something new, it would cost so much to get compatible gear that I'd need a mortgage to pay for it

[jimmydean]

I know a while back (like 2000) there were a few THX and 5.1 systems, but nothing cool enough to catch on.

[hairlesshobo]

I plan to do a 5.1 setup in my truck, but I will be running a surround capable card in my Linux box and just have multiple channels running to the necessary components. Not "cool" by any means, but it will do the trick. I will handle the surround processing using pulseaudio so that no special gear will be needed. The center speaker cutout in the dash is just asking for a center surround channel Lol.

[74baggedbug]

I'm using my iPhone as my head unit.. But didn't want always have a wire plugged in to my phone so I went wireless and use my Bluetooth
Posted via Mobile Device

[jimmydean]

Originally Posted by hairlesshobo

The center speaker cutout in the dash is just asking for a center surround channel Lol.

I am using 2 Kicker 3.5" 2 ways as a center in my 66 dash. Works awesome.

[kikkegek]

Originally Posted by hairlesshobo

I plan to do a 5.1 setup in my truck, but I will be running a surround capable card in my Linux box and just have multiple channels running to the necessary components. Not "cool" by any means, but it will do the trick. I will handle the surround processing using pulseaudio so that no special gear will be needed. The center speaker cutout in the dash is just asking for a center surround channel Lol.

cool! will you have a build thread anywhere here on the forum?

you probably wanna use a non-rotating HD like those new Solid State Disks?

[jimmydean]

Originally Posted by kikkegek

cool! will you have a build thread anywhere here on the forum?

you probably wanna use a non-rotating HD like those new Solid State Disks?

My netbook is SSD, it's awesome. It's been through hell without issue. I will use it to connect the tablet if I don't feel like trying to take it in and out.