wong05tsx

iTrader: (6)

For those who don't know, Mercman's harness is a harness he designed to bypass the stock amp.

2005 TSX w/ Navi

Stereo setup stuff (if it matters at all, or for those who has to visualize it)

Stock HU (Navi)

JL 300/4
Polk Audio 6500db 6.5"
Phoenix Gold rsd65cs Components 6.5"

Alpine MRP-M850
Alpine 12" Dual Voicecoil 4ohm

So I got mercmans harness, Since the stock harness will be disconnected, basically all the speakers will be disconnected, and I am running my amp for my subs thru LOC through the back 6x9's. How would I be able to LOC my sub amp after disconnecting the harness? I plan on disconnecting/removing the rear 6x9's when I do go through with the whole install.

mercman suggests i use RCA “Y” cable to split the L+R rear channels from the harness, however, this would be getting signals from the rear 6.5's speakers not the 6x9's. so wouldn't this bass be totally different?


edit: could i get the left rear speaker + and - and hook that up with the 300/4 amp as well on the same channel as the rear left passanger door 6.5's..? (not sure if that makes any sense at all) ... So on the input for the rear left speaker, I would have two speaker wires going in instead of one (one of them being the 6x9, which is disconnected, i just need power to the wire so that my LOC can get a signal for bass) .... yeah?

mattster

The signal going to your rear doors is full range. You could split the signal from each door and run them to your amp. Then just adjust the crossover on your amp to where you like it (somewhere in the range of the low-end cutoff for your door speakers.) If you do it this way, fading to the rear will drive rear doors and sub, just like stock.

wong05tsx

iTrader: (6)

^kind of confused, my rear 6.5's dont have x-overs? if they do they're built in since they would be coaxles.

do you think you can draw me a little diagram on paint or something?

mercman

When you install the harness you are bypassing the factory amp and all the speakers and crossovers. You can’t use a LOC on the rear speaker feeds because they wont have any signal when you bypass the factory amp. Normally a four-channel amp would have an AUX of output to feed the sub amp. The JL 300/4 doesn’t have this feature. You can feed a sub amp using a short “Y” cable connected to the rear channels as long as the sub amp is also balanced differential. In the case of your Alpine it is not differential and cannot be connected in this way.

If you want to use the Alpine for the sub you will have to install a BALUM to convert the balanced audio feed to unbalanced. If you don’t you will get whine and poor stereo separation.
I thought you were going with the JL 500/2 for the sub?
jeff

jay427

I've got mercman's harness, a JL 300/4 and a JL 500/1 for my subs. I plan to run the front RCA's into the 300/4, the rear into the 500/1, then a set from the outputs of the 500/1 into the rear channel of the 300/4. I'm hoping this is the right way of doing things.

mercman

Spot on. Just set the pre amp out selector on the sub amp to full range and your good to go.

jeff

wong05tsx

iTrader: (6)

From what i read on your other post I thought only whatevers connected to the speaker/component amp would need to be a JL/RF in order to not need a BALUM. Kind of ruins everything since I already ordered all my parts. How do i go about getting one of these BALUM's (and cost?) and how would I connect it when I do get one :\?

mercman

I would have to order some parts to build you a BALUN interface.

Would you consider returning the Alpine in favor of the JL? This would be the best way to go since you wouldn’t need and special adapters. Also the JL has better distortion specs and gives you 500 watts no matter the battery voltage range. The Alpine only gives you 500watts if the battery voltage is 14.4 volts, it is unlikely that you will ever see that type of battery voltage. The distortion on the alpine will double (or more) when you drive a 2 ohm speaker to try to get that 800 watts.

I’m not ragging on the Alpine (I have one in the other car) but the JL is a no brain’er for installation in the TSX and you will get the power it is spec’d for.


jeff

bullyx2

I am doing the same thing with my 300/4 and 250/1 (if the 300/4 ever gets out of the shop) only I am going to feed the front inputs into the sub amp then to the 300/4. I plan to keep it faded to the front most of the time so this would ensure that I am not lowering the signal to the sub when faded to the front.

wong05tsx

iTrader: (6)

im going to have to trade someone the mrp-850 for a 500/1 then...or 1000/1 + cash not sure if its a fair trade, but the price cost is close to each other

could i get a 450/5 and plug the 5th channel to the alpine amp?

bullyx2

If you did a 450/5, you'd want to just run the 5th channel to a sub, that's what it's for.

Another option would be to buy an Audio Control processor that converts balanced to unbalanced. Some one else (saltydog I think) did this to use his alpine amps. Costs more that Merc's BALUN but would give you some extra EQ functionality.

saltyone

Sometimes, people just over complicate things.

wong05tsx

iTrader: (6)

sigh.. should i just forget about the harness and connect the speaker wires to the HU individually. would this give me a distorted signal?

also, i was thinking, what if i got a 2 channel JL amp and bought some 6x9's. and then LOC the rear 6x9's (might bea bit out my budget though)

at this rate.. it'd prolly be cheaper to just get a cleansweep..

wong05tsx

iTrader: (6)

I would do that, except thats not enough power for the subs

wong05tsx

iTrader: (6)

I think I got a deal for a jl 1000/1 on craigslist, now i just gotta sell my amp, i don't have enough cash!!! ahhh! where can i borrow money with low interest -_-?

Spoon

He's intending to use the Alpine amp to drive a sub in the trunk. The sub is mono, so stereo separation is a nonissue. Given the low passed signal and the fact that it's in the trunk, any whine riding on top the signal will be minimal and essentially inaudible. Why would it be a problem to connect a unbalanced input accepting amp in this way, in this case?

mercman

Not true.

He will have to connect the rear outputs of the factory HU to the unbalanced inputs of the Alpine sub amp. This will introduce a whine on his rear speakers and will also kill his imaging.

Your optimal audio performance will be to go with the JL or Rockfords with the balanced inputs. Using any other amp will force you to go with the BALUN that won’t be available for several weeks.

How about doing this,

Sell or return your Alpine sub amp. In the meantime, use you JL as a three channel to run your front components and your sub. You never know, you might be happy with it and you can pocket a few hundred bucks.

Spoon

You're saying that using a Y-cable to split the balanced signal and connecting to both a balanced input amp and unbalanced input amp, the unbalanced connection will corrupt the input at the balanced input amp?

Spoon

Ah, to potentially answer my own question, I'm assuming that by tying either the (-),(+) signal to ground at the unbalanced input accepting amp it would garble the input at the balanced input accepting amp. I didn't see how it would have an impact upstream of the connection, but it isn't upstream is it?

Still, there are things he can do that don't necessitate selling or buying expensive equipment.

He could Y-cable the front input at the 300/4 feeding the front and rear speakers with the HU front output. He'd lose fade control between front and rear speakers, though relative intensity could be adjusted using the gain control at the amp. The HU rear output could drive the Alpine amp, as again stereo separation and whine are not a problem for a sub in the trunk, and then the fade control would be a sub volume level control.

Alternatively, one could use a GLI to isolate the balanced signal at the Alpine amp or possibly before the Y-cable split in the original setup scenario.

mercman

It’s never a good idea to ground the (-) signal output of a balance source. Remember that both the + and – outputs of the HU are “hot” so forcing one to ground shorts an output of the HU.

The best answer would be to swap the Alpine for the JL/500/1 the price is about the same so I don’t see where that would get in the way. It’s possible that he thinks he is getting more bang for the buck with the Alpine 800 watt amp but he really isn’t. To get 800 watts from the Alpine you need a full 14.4 volts from the alternator and that just isn’t a realistic number.


jeff

wong05tsx

iTrader: (6)

I was just trying to see if there was a way to use my alpine amp without all the complications. I found a local deal on a used 500/1 amp, i just need to find a way to find 200$ in cash somehow before he sells it to somebody else. WAMU doesn't let you borrow money do they :\?

jiggaman

my TSX system has alpine amp for my components and kicker amp for subwoofer with no engine noise. why is this?

wong05tsx

iTrader: (6)

so this is basically how its gonan be wired with a 300/4 and a 500/1 to still got full functionality of the HU fade/bass control?

power+ grounds too of course

bullyx2

Look right. I can't tell from the pic if you are splitting on of the balanced lines from Merc's harness. You do not have to. To be safe, what you'll do is run one pair from the harness to the front or rear of the 300/4 (your choice). You'll run the other pair to the inputs for the 500/1. You will then get another RCA cable and run it from the pre amp outputs on the 500/1 to the other pair of inputs on the 300/4.

Most people run the rear to the sub amp, then back to the 300/4. I am using the fronts, but really your choice. Also, I'd recommend setting the output on the 500/1 to full range, then using the x-over on the 300/4 to filter out the rally low stuff from your mids and highs.

mercman

Did you install it yourself? If so how did you connect the amps to the HU?

jeff

Spoon

Gain setting probably not all that high. Do you by chance have a line driver and/or a GLI in the path?

Spoon

There really isn't anything unsafe about splitting the signal. If he already has the Y-cables he should use them, if he has an extra set of patch cables lying around, use those, either way, no difference.

mercman

wong05tsx

do it this way.
Take the rear two channels from the Harness (RR and LR) and run them to the JL500/1. Connect the front two channels from the Harness (RF and LF) to channels 1 and 2 of the JL300/4. Run a short RCA patch cable from the JL500/1 preamp output to channels 3 and 4 of the JL 300/4. Set the “output mode” selector switch on the 500/1 pre amp section to full range. Adjust the gains as described in the JL manual and your good to go.

jeff

wong05tsx

iTrader: (6)

thats pretty much what i drew right? sorry i'm a visual/hands on learner ;x

after hooking it up like that i just change the output mode on the 500/1 to full

Spoon

I'm sure you've figured it out by now, but what the hell, this is what he's saying:

jiggaman

i have already spliced my factory tsx harness and dont really have any engine noise except for an occasional snapping sound. this snapping sound only occurs when i have AC running.

do you think that if i replaced my harness with a brand new one and used your adapter this snapping sound would go away?

also do you have an adapter that is compatible with alpine amps yet?

jiggaman

yes two line drivers.

Spoon

Manufacturer and model could help explain your situation, but than again, maybe not.

I have used different equipment and have not hooked the HU output to a balanced input amp, in some instances I had noise, some I didn't, I don't even remember all the configurations I ran. Although I know there are some posts in a few threads from a little over a year ago where I've complained or relayed successes, I'm not that curious to go searching.

Possibly your line drivers accept balanced inputs, perhaps not. Maybe with the amp gain set low, you don't really notice the noise. Are your speakers coaxials or the tweeters on the dash? Why you don't experience a whine isn't a mystery, just that there are a few variables involved.

For instance, I recently switched out an amp for one with more power and a better signal-to-noise ratio. Immediately I noticed alternator whine, I didn't have it before, I figured it was a bad amp. Long story short(er), in accumulating evidence to prove the amp was bad, I discovered, no, it wasn't the amp. I was picking-up inducted noise into the RCA cables near the firewall, something that was never touched on the new amp install. Rerouted the cables, no whine whatsoever. Incidentally, the preexisting amp was an Alpine and I never noticed the whine before - an this is coming from an aftermarket deck, so it's isn't a balanced/unbalanced issue, although it does highlight the advantage of running a balanced signal to the trunk, the TSX is noisy.

Mercman's harness and overall solution is definitely the way to go for anyone who wants to do it once and not be bother with troubleshooting. Dude showed up on the board about a year and a half too late for me. I can't speak to your snapping, but it certainly doesn't sound right.

wong05tsx

iTrader: (6)

just got the 500/1 today, hooked it up thru LOC (until i get my 300/4 at the end of this week, and mercmans harness in the mail as well), and im getting a humming noise when i turn the car OFF. it lasts about 20 seconds and then it stops (the power LED light on the amp is also on during the humming, and stops when the light goes off)

i also tested every wire and found that its the RCA plugs causing this, is it because the rca plug is unbalanced?

any way to fix this temporarily just until i get mercmans harness and the other amp set up?

mercman

It sounds like you tapped the wrong wire for the remote turn on.

jeff

wong05tsx

iTrader: (6)

hmm, it's tapped into the navi unit in the trunk - same place it was tapped into when i had my alpine, but never had this problem, only got about 5ft of remote wire, dont have too many options

bullyx2

Merc is right, you tapped the wrong wire for a turn on. Whatever you tapped still apparently has power for a while after the car is turned off. Mercs harness has a turn on wire, until then I'd recommend maybe tapping the 12v+ from the 12v socket near the "not an ashtray", or just living with it until the harness arrives.

wong05tsx

iTrader: (6)

Thanks, i just unhooked the amp and gonna just wait for everything to come in, got the harness this morning mercman, thanks for the quick shipping