Samsung Galaxy 4 7" Tablet install

[Shinare]

The only problem with the volume knob is that it introduces an ever so slight hiss that gets louder and then back softer as you increase volume...like a bell curve. I assume it's my knob anyway from that observation. heh

[ezhacker1]

yeah, i know what you mean. I always attributed it to a bad ground. Speaking back to hissing/electrical whining when charging i connected a wire between the two grounds of the RCAs at the Amp side.

Another thing i encountered was my sub would pop, like also bad grounding. I put a ground loop isolator to prevent this but it lowered the gain of the signal audibly.

My system isnt high powered at all, but still maybe i should find/do better ground. Maybe Big 3?

[Shinare]

CTScott's suggestion that I try another (better) charger was really what got rid of the horrible electrical noise while charging. The charger I found at my house was an old sprint charger that is both a car and an outlet charger at the same time (it has electrical plugs that fold up into it when using as a car charger). The only thing left is the every so slight hissing (like quiet static white-noise) that fluctuates with the turning of the volume knob. When I get some time I will completely remove the volume knob and see if the hissing goes away. If so I will endevor to find a better solution to my easy volume adjustments. For now I downloaded an app that puts a little floating volume slider on the screen and I leave the volume knob at the "optimum" position where there is ZERO hiss, which is at about %75 volume. going down or up from that point increases hiss loudness untill, when lowering the volume, it goes away because you have turned the knob all the way down.

[Shinare]

OK so a quick (or not so) update since my last post just so that anyone thinking of doing this can benefit from my experiences:

The hiss: ... is annoying. I really wish I could figure out how to get a volume control knob and not have the hiss, but removing the knob actually makes the hiss massively worse. Having the volume on the knob set to %75 makes ZERO hiss. I thought it might be the specific knob, so I ordered another brand of one off of amazon that a reviewer specifically said did not introduce a hiss sound. It behaves exactly the same as the other knob with the exception of actually cutting out the bass and midrange as you turn the volume down leaving only a hollow tinny treble sound when at low volumes. Booo

I added an "RCA Ground Loop Isolator" in between the knob and the amp. That seems to have helped A LITTLE but I still leave the volume knob on %75 and adjust volume with tablet because at %75, ZERO hiss. (inexplicable to me)

I also noticed that when I moved around my volume control knob that sound would cut out from two of my 4 speakers. Oddly, when those speakers cut out the HISS would also massively increase in ALL speakers... weird... I discovered that one of the RCA plugs on the "El Cheepo" wire that goes from tablet to volume control knob was flaky. I ordered from monoprice the "Premium" version of the 6' headphone jack to 2RCA wire. It is MUCH thicker and touts 22AWG which to me sounds pretty small, heh. But it must be thicker than normal stuff because the shielding has a much larger OD. Adding that in had an unexpected side effect of making the audio much (very noticeably) louder. *shrug*

I then turned down the gains on my amp to half (because of the loudness introduced with the new wire) and while that lowered the hissing just a bit more, its still there, and doing that made it almost not loud enough to listen to while driving on the highway with all the road noise.

So I got to reading around, and it seems that setting the gain on your amps is kind of an art so I twisted and turned them a bit more and found a spot where when the tablet is set at volume 14 of 15, its loud enough I can mostly hear it over the road noise, and when not moving can turn it down with the tablet. If I turn the tablet up to 15 of 15 then I get what I can only think is what is called "clipping" from the amp. A popping happens when a particularly loud sound happens. Most likely when someone on my talk radio channel says a word with the letter "p" in it, heh. (or bass hits in a song).

I've heard of "grounding" issues when using the car's harness for your ground for amps, so I ran a special 14awg (speaker wire) ground wire to the grounding point in the driver's kick panel for the amp and power adapter for the tablet to share. Did nothing to help.

Anyway, more reading, and thought maybe its the cheapo amp I am using ($40 off of amazon 100Wx4). But then an amp is only AMPLIFYING the signal its receiving so I dunno... maybe the hiss is a product of power to the tablet and I just cant hear that un-amplified hiss in a set of headphones when power is supplied to the tablet.

I'm no electrical genius and have no idea how to make the power filter that Scott was nice enough to describe to me hehehe. Hell I can't make heads or tails of that diagram. :) (I really appreciate the info tho Scott and appreciate you trying to help)

Everything I have done to this point has actually helped things, but the hiss is still there when I adjust the RCA volume knob so as it stands I leave that at %75 and use the on screen volume control on the tablet which is near dangerous when driving, heh.

I love the idea of having that tablet in the car but I may just go back to having the stock deck in there and plugging in my phone to the AUX port. *shrug* I've spent close to $200 so far trying to not spend $350 for one of the chinese "Android" head units that also come with backup cameras and native FM reception... again... heh


EDIT::: Oh, I almost forgot, I ordered a cheap bluetooth receiver off of amazon because I read plugging that in to the amp and connecting to it from the tablet totally removes the car sounds and hiss. LIES!!!! Another $20 wasted on this project, heh. Still heard computer noises AND hiss, and, extra bonus, I had to "connect" the bluetooth receiver EVERY TIME I turned on the car because it would not remember the tablet connection. The tablet remembered the receiver but it couldn't connect to it until I pressed the button on the receiver. Worthless.

[rye7jen]

What about the positive wire going to the amp? is it parallel with the RCAs? Try to put them in a separate direction, if so, check your tablet, put some insulator on every side of it like a thin rubber or a foam. Try also to completely remove the whole tablet from the center console and play some music then check if the hissing sound is still there.

[Shinare]

Originally Posted by rye7jen

What about the positive wire going to the amp? is it parallel with the RCAs? Try to put them in a separate direction, if so, check your tablet, put some insulator on every side of it like a thin rubber or a foam. Try also to completely remove the whole tablet from the center console and play some music then check if the hissing sound is still there.

The 12V+ wire and 12V+ ignition switched (remote) wire are both from the radio harness (metra kit harness plugs for Toyota) and are parallel with the RCAs, they (along with the speaker wires from amp) are in a bundle that is hidden under the center console and exit that to under the passenger side seat to amp and volume control knob. I've read a few times that one should run a separate 12V+ constant directly from the battery to the amp but I have not tried that as the amp is only <40W (actual) RMS per channel. Was hoping I could use the power supplied by the radio harness. It was OK for the amp in the stock head unit... Perhaps it is time to try that and route it under the passenger side door trim. I'm also thinking about getting a different amp, but running the cable will be free, the amp kit I am looking at will be another $50. Sooo I will probably do the +12V amp wire this week some time.

The hissing is present with the tablet out of the dash. The only time it is not present is when the volume control knob is turned all the way up, then its crystal clear.

[rye7jen]

Try to separate the RCA/Speaker wires away from the 12+ wire and remote wire from it. That might be the problem. Much better to purchase a amp wire kit to install your amp, even if it only gives an output of 40W.

BTW, how did you ground your amp?

[Shinare]

I tied the ground for the amp and tablet charger together and ran a 14-16AWG (I think) speaker wire to the grounding point under the driver's side kick panel. I thought it might be that I am sharing the charger ground with the amp ground but I plugged the tablet in separately into the cigarette lighter port and there was no difference.

I guess today I'll run another bit of 14-16AWG speaker wire to the battery for 12V+. That's the largest gauge wire I have and definitely thicker than the wire hardwired into the amp I will be crimping on to. I will also extend the remote wire with it so it can follow along the same path as the 12V+ constant.

[Shinare]

So I spent a little time this morning following the wire install guide in this forum. Ran the wire through the gramet next to the ECU. Then attached one end the battery positive, attached the other end to the wire just before the fuse to the amp. Turned it all on and the amp light came on with the remote wire . But no sound. Thinking I installed the positive wire wrong I hooked it back up the old way, the amp still did not produce any sound . I think my amp is dead . Looks like the dream is dead for now. Maybe I will get a new amp someday.

[CTScott]

Amps usually have a power wire and a remote turn on wire. You may just need to power that wire to bring it to life.

[Shinare]

Yeah, what I had done was just directly wire the 12v to the battery. The remote wire was still attached the way it was before to ignition switched power. maybe my problem this whole time was a bad amp. I bought this "4x100" amp a couple years ago off of Amazon for $30... I'm kind of tired of messing with it right now lol. If I get some money I think I might try one of those Chinese Android head units.

[IllusionX]

While searching for a CarPlay headunit, I stumble on one of these from pioneer that you must plug an android decide to use as a screen.

I can't remember which one. I'll try to find it again when I get on a computer..

[Shinare]

Thanks, I'm open to ideas. Hehe :)

[IllusionX]

It's one of the appradio from Pioneer that supports Android. I can't wait to save up and get one of them so i can use it with my iPhone in CarPlay mode..


http://www.pioneerelectronics.ca/POC...pRadio.Compare