Engine Noise :(
 

Ok.. So I've been fighting with Engine noise for the past week. I added 2 amps and a MTX RE-Q to my factory Bose w/ Nav.

Equipment:
RF Punch 600a4
RF Punch 250.1
MTX RE-Q
RCA Tsunami 4 Ch Shielded Cable
Speaker Cable: Stinger 9 Conductor Speedwire

Power & Grounds on Right Side of Car
Speaker wires on Left Side (RCAs no where near any of them)

I grounded the amps and RE-Q to the bolt that sticks out of the car where the factory amp was mounted. I bought a Multi-Meter but haven't a clue how to use it to check the ground. (But I really don't think it's my ground)

I have 4 awg Power cable to a distribution block that goes into 8 awg for each amp and the RE-Q is connected to that block as well.

The Remote Turn on is coming from the lighter outlet under the glove box because the Bose Remote wire isn't strong enough to power on 2 amps. I am not using the factory harness for grounds or power.

So Far:
1. RCAs connected to the amp disconnected from the RE-Q no engine noise at all.
2. Connect the RE-Q back up and it's there. It gets worse when i turn the gains up on the RE-Q.

The stereo sounds really good with the engine off or turned up 50% with the engine on but when turned down the noise is going to drive me nuts.

Has anyone else had expierence with the Re-Q and engine noise? I'm going to try to hook up a passive in-line converter tonight to see if goes away. I also moved the RE-Q a few times and I noticed it gets better and worse depending on it's location.

Also there's a sheild cable included on the stock harness. that connects to the bose subwoofer. I'm wondering if that had something to do with reomoving noise on the stock system. Any ideas about that?

If anyone has any tricks that might help it would be appreciated. I'm tempting to get the RF 360.2 or Audiocontrol Line Output converter but i hate to throw money at this and it not fix the problem.

Any help or suggestions would be appreciated.

Thanks,
Weapon

Okay how good are your grounds? Did you sand them down to bare metal before hooking up any of the grounds? Also Where are you getting power from for the re-q?

I would run separate power and ground for the RE-q and see if this solves the issue, make sure wherever you have the amps and re-q grounded is bare metal contact. a bolt may not be good enough. Can you get a pic or 2 of everything?

I'll get some pictures up tonight. I was so tired yesterday and took a break.

Good idea both taking a brake and pictures. You never want to work on something when you are tired and flustered.

What strikes me odd is moving the Re-Q makes the noise change. That either points to RFI (which I strongly doubt) or a bad/loose ground. Leave the Re-Q in place and fiddle with the ground connection- does that have the same effect? If so then you have a good direction to go.

I think you might have a bad piece of equipment somewhere in your chain with an open ground.

Try disconnecting each component one by one. For the EQ, bypass it and see if it is the culprit.

The RE-q is a line out convertor, Im willing to bet it is RFI like Division said, try runnin a separate power wier and better ground and see what happens.

He has already said that if he disconnects the rcas from the amp of from the re-q the noise goes away. Like I said check your grounds also you might want to get power to your re-q another way other than the dis block.

Ahh, I didn't realize it was a Line out converter, I thought it was an equalizer... lrn2google... That being understood, it almost has to be RFI.

I took a look at the Install sheet for the Re-q... Could you tell us where it is physically installed? If you're extending the speaker wires to the back of the car, you just created some 8ft antennas. Those wires are picking up any interference, then sending that 'dirty' source to your amplifiers... Any noise on those lines is now 'amplified', (couldn't think of a better word for it) and a whole lot worse than it once was. The fact that turning your gains up on the Re-q makes the noise worse, almost confirms that the noise is on the lines 'before' the Re-q...

That could be the problem. But like we said check your grounds and also more the power wire from the dis block and get power threw it from another way other than from the dis block. If the re-q is in the trunk you might want to try moving it closer to the from that way the speaker wires are shorter. The ones I have installed were put under the seat.

I placed it where my factory amp was located and added about 1 ft of cable so i can easily adjust if i needed to.

I've been reading up on the G37 forums and it seems that the Bose Headunit in their cars sends a flat Level Line to the factory Bose amp. The sound is processed and crossedover for each speaker from the factory amp. I wonder if this is the problem and i don't even need the Line Out Converter from the RE-Q. What happens when you convert a Line Level Out to a Line Level Out?

This so far makes the most sense since the input Wires were sheilded and wrapped vs. the the speaker wires that were just standard cable twisted together.

You still need the re-q to control all of your balances and all before going to to the new amp. The ones I have done I have kept the amp and taped into the wires coming OUT of it. I knwo some re-q's can accept a low level input I am not sure if yours can or not.

Ferrite is an effective means of squashing RFI- I've never used them in this application, however depending on how desperate you get, it may be an option. You should be able to pick up some snap together chokes at radio shack...

:icon08::ugh::wtf:

Another problem could be that a lot of these boards in radios and other equipment that hooks into your RCA's has little bitty fuses on them. When you just barley accidentally touch that positive prong of your RCA to the negative "jacket," while there is a signal (or sometimes not), it can blow those fuses and cause insurmountable grief. Mid to low level Pioneers are notorious for this. Have you tried (and I hate do thing this) grounding your RCA's?

^^^ it is true i use it in 100K dollar VFD's all the time on rs-232 conectors. cannot see why it would not work for your application

If you are talking about picto fuses I have only seen them in pioneer premier head units.

Ok... Sorry no pics yet but.. I think I solved, well not really solved but I got rid of the problem. I hooked up the Inputs from the Bose Head Unit to a Passive In-Line Converter "Scosche SLC4" I've had one laying around for years and have never used it.

Disconnected the RE-Q. The RE-Q i have is the 3 channel version. No Noise at all. Ran the engine turned on all the lights, A/C etc... It sounds crystal clear and louder than it did with the RE-Q.

With RE-Q i had to turn up to 40-50% to hear sound. Now i start to hear sound at the first dot.

I need to get one more Converter for the Sub channel and I'll call it good. I cranked it up and didn't notice any fade in the bass or high frequencies which leads me to believe all the EQ saftey crap is that happened before is taking place at the stock amp. Exactly the same things I've read on the G37 forums and 350Z forms about the the Stock HU.

I don't know what the heck is wrong with RE-Q. I checked all my grounds and they were all reading less than .5 ohms which to my understanding is perfect. I wouldn't doubt the it was defective. The only authorized dealer in Tucson is the one audio store i hate "Audio Express" and took a chance of buying something there thinking i wouldn't have any problems.

I swear I honestly think they sell you crappy equipment if you don't purchase their "Extra Protection Plan" I've purchased a couple amps there one with the protection on without. Needless to say the one without the protection crapped out within a month. The one with the protection...it's still working today after 10 years.

Anyhow I appreciate all your guys' help. I feel much relief now that i have no whining.

As soon as everything is back mounted and put together I'll post some pictures.

Thanks again everyone :)

If you don't know/understand/or just plain get it.... google it.


Ferrite Cores for RFI Suppression


Cylindrical EMI suppression with ferrite cores

+1

As I said before the bose system dose that to the signal than sends it out. You need to try a different place to get your power and check your grounds. I keep reiterating that. The power wire should not be connected to your fuse block.

If that's true, then one could replace everything but the head unit for those with Bose....

Hmmm.....

I'm really really really interested in this thread and how it all came out. Would love to see some pics and get info about how it all sounds put together.

-William

Yes as I have said before you can keep your factory head unit you just have to invest in some other stuff to make it work with your aftermarket amps and all. Anything is possible with enough money. I personally would rather have a new head unit and everything running directly from it. That way everything is working with no variables such as the re-q or the jl clean sweep.

I love all the info you give out here, it's always detailed which is great for audio idiots like me, but the only reason I like this idea a little better than replacing everything is keeping existing nav, bluetooth, and the stock look. So I definately cant wait to see this finished and if the OP is willing a review on the sound as well as approximate cost he put into the new equipment.

-William

No one is an idiot in my book. I look at people that do not know things and they are not idiots they are just uneducated about the task at hand.

Ok... Everything is all put back together and working fine. 0 Engine Noise.

[ Bose Head Unit ] Has 4 Channels FL/FR/RL/RR (Full Range)
Those 4 channels go into the [Stock Bose Amp]
Stock Bose Amp crossedover with 7 Channels 2 Tweeters/2 Mids/2 Rears and 1 Sub.

Bose Head Unit goes into a 4 channel Line Out Converter
-Front Channels goes to Amp 1 (RF Punch 600@4) Running Focals 165VS Bridged (300 watts aprox)
-Rear Channels go to Amp 2 (RF Punch 250.1) powering 1 12" Armegeddon MSeries (500watts @ 2ohms) So now my fader works as a Bass Volume Control.

I can tell I need some more EQ control and will probably get RF 3Sixty.2 to help out with that. But as far as SQ it's not bad and way better than Stock. Kind of hard to make fine tune adjustments with only Bass and Treble +/-

The Engine noise, I am going to blame on the a faulty RE-Q because I have 0 noise now. No popping, no hissing, no whining, nothing.

For those of you looking into upgrading the the sound in the Bose System and keep the headunit it can be done and there a few different ways it appears you can do it.

Stock Bose:
Adding Sub&Amp Only
-Easiest Way - Take the Output Sub Signals from the Bose Amp to a LOC or RE-Q

New Speakers Amp & Sub -
-Option 1 - Take the outputs (7 Channels) from the Bose Amp Sum them together using Cleansweep, AudioControl RE-Q5 etc...Hook up to amps
-Option 2 - Take Inputs from Bose Headunit that go into the Bose Amp (4 full range channels) to a LOC (no need for a summing device) and hook up to amps.

Pics coming soon.

Sigh" It is not a faulty re-q you just needed to find a different place to get power from you are not suppose to get it from the block. You are suppose to get it from a power wire like behind the dash or somewhere in the fuse block. It was not faulty at all people encounter engine noise all the time and than they start moving the ground and power wires to a different conection or the rca wires until it goes away.

:iagree::iagree: Both you and bigaudiofanat are correct. The noise is probably caused by a ground or a power wire. Sometimes you hook up something and get engine noise. A lot of people think that it is automatically a faulty unit. This is usually not the true case. It is were the power is coming from and how it is getting to the unit that usually has a noise in the power wire. In your case Bigaudio is right you should not of had the power wire hooked up tot he dis block. It should be hooked up to a wire in the fuse block or behind the head unit. Getting power directly from a power wire coming for them engine bay has tons of interference in it, that your re-q probably amplified. I also think that you should put it back in. The re-q dose so much more than your line converter and the boes is still messing with the signal before your amps are getting it. That is why you are saying that you are only hearing a bit better sound quality and not a lot. Keep up the good work bigaudio and I can see that speed know some stuff as well. Glad you know each other big and speed.

Engine noise in the vehicles stereo speakers. It’s a pretty common problem when an aftermarket radio or amplifier is installed. The most common description of the noise is a whining sound that gets louder as the engines RPMs increase. This is very annoying and sometimes embarrassing. If your new automotive stereo system is causing unwanted engine noise the fix can be relatively simple.
The normal cause of engine noise in the stereo system is the ground. In any 12 volt system there is a 12volt + and a 12volt -. Often times a vehicle manufacturer will ground all of the dash instruments to one central location. This is great for them but bad for car stereo enthusiasts. When we hook up our new stereo we often times (if done properly) will use an installation wire harness. This wire harness will match up to the vehicles wiring exactly. So your ground and power are coming from the fuse block and a central ground location (vehicle standard).
A simple solution can usually fix this engine noise problem. Change the stereos ground location. Most times this can be done and un-done (if it doesn’t help) very easily. Behind the stereo will be anywhere from 10 to maybe 16 wires coming out of the stereo into a wire harness clip. Between the stereo and the first wire harness clip you will need to cut the ground (Black 12V-) wire.
This will break the ground and the stereo will not turn on at this point. The part of the wire that is coming from the back of the stereo will need to be lengthened and run to an alternate grounding location. Most of the time there is a bare metal dash frame under the upholstery that you will see when the stereo is removed from the dash.
With a digital multi-meter in hand you may test for a good ground source. Make sure to set the meter to test for continuity. You can make sure that the meter is set correctly by touching the lead ends together, this should give a beep or chirp from the meter letting you know that there is continuity. Clip one of the meter leads to a known good ground (somewhere in the door jam usually works) and then you may begin looking inside the dash cavity for a ground location.
Once you have a beep or chirp from the meter you know you have found a ground location. We’ll only know that this is a good location or not once the ground is hooked up and we turn the stereo on. Until then, cross your fingers and hope for the best. Hooking up the stereos ground wire to the new ground location is up to you. Every situation is different so you may need a crimp end or some other modifications inside the dash cavity to get the ground wire hooked up.
Just changing the stereos ground location will often resolve the engine noise problem. When this doesn’t work we resort to a “Ground Loop Isolator” or “Inline Noise Suppressor”. There are a few different styles that are used for different applications.
There are noise suppressors that are used in the power line, in the RCA/audio cable lines and some with 3.5mm stereo cable input and output. You must determine which is right for your application.
Some stereos will only create this whining when there is an auxiliary audio input used. These will usually be something like an MP3 player. There are ground loop isolators for use with MP3 players.

Ground loop isolators are a last resort as they can omit or fade out certain freq in the sound, including ones that music would usually come out at. Always check different power places and ground as well before using one of them.

Noise suppressors are the last resort, as I stated earlier, and it might be the only resolution for engine noise problems.

http://www.the370z.com/members/the-w...1-dsc01254.jpg

http://www.the370z.com/members/the-w...0-dsc01253.jpg

I exchanged my RE-Q and the new one is working fine. The engine was the unit and not my install. It sounds a lot better with the new RE-Q and had i received a working RE-Q this install would have been easy and quick.

Total Cost for the RE-Q 5 $175

As far as sound quality I have to say I'm very impressed with what the RE-Q does when it's not making a bunch of noise.

question about my ground loop issue
 

I had a hu replaced with no ground loop problems. Then I installed an amp and replaced all the speakers as well. Now I have a ground loop, which is annoying. Does this same technique work for my situation, since I grounded the amp to the frame in the middle of the car? Just checking, or if I have to do something totally different to get rid of my new ground loop. Thanks in advance.

How and where did you run your rcas and power wires? Did you sand the ground spot down to bare metal before putting the ground wire on? Were did you ground your head unit too? Also what kind of amp is it?

the hu was installed using the factory harness connector. so i believe it was connected to the ground through that connector. I would have to double check that to be sure. I ran the power along the passenger side and speaker wires with rca along the driver side and the remote lead as well. Figured those would be ok due to low power, compared to the power wire. Jl 900 5 amp is grounded in the trunk to a bolt that I didn't sand because it was pretty large in size(thought it would suffice). I am just wondering if the hu wasn't grounded accept for the factory connector it is connected to. (I never installed the deck, just
added the rest)

You have to have a clean metal surface so go to your ground and SAND the paint and all off. Also as far as I knwo and all the head units I have put in the z's there is not factory ground wire that is used in the aftermarket harnesses. So I would check on those if you did somehow use the factory ground unhook that wire and ground it to one of the 4 bolts were the shift knob is. But the most important thing is to sand that primer and paint off that ground spot.

I looked at the pics on the web site that was linked to your response, and noticed you had a blue 370z you did an install on. In the back where the crossbar is (the one directly behind the seats) directly below that in the little cubby of the trunk there are two silver screws attached to a black tab that is screwed to the trunk. The one on the left is where I bolted down the ground. So, should I take the bolt off and sand off the paint from that, or can I move that tab so that I can sand the trunk below that and mount the ground between the black tab and the trunk itself? Or, is there a better place to put the ground?

Sometimes it does not matter were you put your ground wire, yes you could put it were I put mine at. BUT you have to sand the spot.. Electric can not travel easily with paint and primer on top of the metal.