[Repost: Posted this in Digital Line Level when i think it should be here]
Okay guys, massive noob here so bear with me, trying to understand everything as best I can, not even sure if this is the right forum or if it should go in the car section but I _THINK_ this is the right place :F
Basically I wanna hook a tablet into my dash to replace my head unit but it will take up all the available space. I'll be running a DAC DESTROYER that i got off ebay as a USB DAC running to my 5ch amp. Since the tablet will be permanently mounted into the dash I won't have any decent access to the volume control. Also, the output will obviously only be two channels. I'm pretty sure that's okay though, I think its safe to just bridge the RCA's at the amp to power the rears and sub, not too certain if this is okay when you start talking impedance but from what I gather, that's more important on the amp's output? :F
Anyway, the question is, I really don't want to lose a physical volume knob and I want to keep some fader control because my rear speakers are pretty terrible and don't want them kicking as hard as the fronts. I know I can control this at the amp and I _THINK_ with the usb dac I will still have volume control from the tablet, but that's a bit shitty. Having a proper volume control that's accessible instantly seems pretty important. The only place I can think of mounting knobs on the centre console now will be in the ash tray.
http://www.goauto.com.au/mellor/mellor.nsf/0/AFAA1A50CCEFDFE0CA256B66000738A3/$file/2001.8.3nB3P01E_con_Subaru_ImprezaRV.jpg?OpenEleme nt
bit small, but if you look closely you can see the spot im talking about is next to the cigarette lighter socket which I want to keep so I can't just hack in a half-din eq.
Is there any solution to this? I'm competent in electronics (just don't know much about audio) so if there's a diy solution i wouldn't be too afraid of attempting that. Pretty much want to go from USB DAC [2ch rca] -> Volume/Fader [4ch(or 5ch) rca] -> amp with a small footprint on the volume/fader.
Any help would be greatly appreciated!
Okay guys, massive noob here so bear with me, trying to understand everything as best I can, not even sure if this is the right forum or if it should go in the car section but I _THINK_ this is the right place :F
Basically I wanna hook a tablet into my dash to replace my head unit but it will take up all the available space. I'll be running a DAC DESTROYER that i got off ebay as a USB DAC running to my 5ch amp. Since the tablet will be permanently mounted into the dash I won't have any decent access to the volume control. Also, the output will obviously only be two channels. I'm pretty sure that's okay though, I think its safe to just bridge the RCA's at the amp to power the rears and sub, not too certain if this is okay when you start talking impedance but from what I gather, that's more important on the amp's output? :F
Anyway, the question is, I really don't want to lose a physical volume knob and I want to keep some fader control because my rear speakers are pretty terrible and don't want them kicking as hard as the fronts. I know I can control this at the amp and I _THINK_ with the usb dac I will still have volume control from the tablet, but that's a bit shitty. Having a proper volume control that's accessible instantly seems pretty important. The only place I can think of mounting knobs on the centre console now will be in the ash tray.
http://www.goauto.com.au/mellor/mellor.nsf/0/AFAA1A50CCEFDFE0CA256B66000738A3/$file/2001.8.3nB3P01E_con_Subaru_ImprezaRV.jpg?OpenEleme nt
bit small, but if you look closely you can see the spot im talking about is next to the cigarette lighter socket which I want to keep so I can't just hack in a half-din eq.
Is there any solution to this? I'm competent in electronics (just don't know much about audio) so if there's a diy solution i wouldn't be too afraid of attempting that. Pretty much want to go from USB DAC [2ch rca] -> Volume/Fader [4ch(or 5ch) rca] -> amp with a small footprint on the volume/fader.
Any help would be greatly appreciated!
It's good to have a real volume control between the sound device and the amps. Particularly if it's illegal to use a touchscreen while driving. If the car includes steering-wheel mounted controls, figure out how to use those. Some USB audio devices do include internal volume control ability, and have inputs for volume control buttons.
You might get away with just using a couple of passive stereo pots; use the first pot as the main volume control, and feed the front channels directy. Use the second pot to reduce the volume as necessary to feed the rear channel amps. I assume the multichannel amp includes an active crossover.
Now, you could run into problems with ground loops between the tablet and the audio stuff. Ideally, I would use either balanced lines or isolate the source using an S/PDIF digital output. $20 on eBay would get you a small and probably not horrible DAC that could be mounted up front or back with the amps. You could get motorized pots to use as remotely mounted volume controls. (I think I got one from Digikey, made by Alps.) The motor could be controlled from a DPDT spring-return-to-center-off switch of some kind (rotary, rocker, toggle; perhaps a power window switch).
Alternatively, there were car digital surround processors like the Panasonic CY-AC300; you could feed one of those from S/PDIF and use the remote faceplate for volume. Those kinds of boxes were expensive, but not popular; I found one on the bargain table at a car audio dealer.
You might get away with just using a couple of passive stereo pots; use the first pot as the main volume control, and feed the front channels directy. Use the second pot to reduce the volume as necessary to feed the rear channel amps. I assume the multichannel amp includes an active crossover.
Now, you could run into problems with ground loops between the tablet and the audio stuff. Ideally, I would use either balanced lines or isolate the source using an S/PDIF digital output. $20 on eBay would get you a small and probably not horrible DAC that could be mounted up front or back with the amps. You could get motorized pots to use as remotely mounted volume controls. (I think I got one from Digikey, made by Alps.) The motor could be controlled from a DPDT spring-return-to-center-off switch of some kind (rotary, rocker, toggle; perhaps a power window switch).
Alternatively, there were car digital surround processors like the Panasonic CY-AC300; you could feed one of those from S/PDIF and use the remote faceplate for volume. Those kinds of boxes were expensive, but not popular; I found one on the bargain table at a car audio dealer.
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remote volume control:
http://www.ti.com/lit/ds/symlink/lm1036.pdf
single control pot physically small
http://www.ti.com/lit/ds/symlink/lm1036.pdf
single control pot physically small
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