2005 Honda Odyssey, stereo severe feedbac

HELP ME

Can you believe that I can't find an installer here in Miami that can give me a resolution to this problem?

My van is a 2005 Honda Odyssey (Touring edition) which comes with mids, highs and a subwoofer with amp..  which they call their top of the line premium system.   Of course the system has no power and it pretty much sounds like sh*t to my critically listening ears..

So I bring my van into a very reputable audio installer's garage to upgrade my system.  I don't need much quad.. in fact I prefer a tight punchier sound than anything else. 

We agree on upgrading all of my mids & highs to MB Quartz and to build a custom box which will fit into my spare tire space in the back, using a JL 8" sub.. 

We installed two 4 channel Fosgate amps, one for the mids and highs and one for the sub.  I don't mention specific models because I think it's irrelevant to my situation. 

Here's the major issue that no one seems to be able to answer for me...

This model of Odyssey has a feature called economy mode.  The van switches from 6 cylinders to 4 cylinders whenever the car feels it doesn't need to be using 6.  For example if your cruising at like 50mph and you decide to let off of the gas pedal....... the car coasts, instead of coasting using 6 cylinders it will shift down to 4 cylinders. 

Well this downshift, if you want to call it, evidentally causes a current change in the cars voltage which in turn causes a severe feedback into the subwoofer.  The feed back gets so deep it almost sounds as if I have a few 15" subs in the back.  It's a painful sound to hear and I have two daughters under the age of 3 which makes this most definitely untolerable.

The system itself sounds top notch...  The installers did a wonderful job.  Looking at it with a critical eye the installers were every bit professional, but this feedback issue has left them stumped.  They have tried everything you can imagine.  I left the car with them for 4 days and they still couldn't resolve the issue.. He even told me in his 22 years of experience he's never had an issue like this which he wasn't able to resolve.

Ultimately, I had the entire system removed and now I'm left with my stock system.  It has been a real let down for me.  It's a brand new van and I wanted it to sound as good as it looks and from the feed back I've received it's impossible.

Some body please help...

Feel free to contact me personally any time at (786) 344-5412....  I'm on eastern standard time... 

My name is O.J. 

Not being there the only suggestions that I have are the following:

• if in fact there is a voltage drop that would affect the performance of the amplifier when the transmissions switches from 6 cylinder to 4 cylinder, I would run a power wire from the alternator ( fused ) directly to a Optima battery designated for the audio system. This will isolate the power from the rest of the system and the affects of the voltage drop from the rest of the car
• If they used a PAC trunk LOC they would have been able to use the low level output of the OEM radio & converted it to RCA outputs.
• Make sure to test the power wire off the battery for the amplifier's to see if there is infact a voltage drop when the transmissions drops from 6 to 4 cylinders. Also test the voltage from the preamp wires on the LOC for any drop in voltage.
• Check for an absolute ground on the LOC as well as the amplifier to ensure proper grounding location.
• I'm sure they used triple shielded RCA's

Talentco

Hey Im in Lauderdale, take it in to the honda dealership take it to Coral Springs Honda if you can and have them disable the economy mode, my wifes mother has an Odyssey and she hated that feature, the dealer charged her 200 bucks to do it, since it required rewiring and reprogramming of the computer
after that your problem will be solved.. you'll just get less MPG

But thats only one idea.. im sure others will add more to this thread

Later
Skold

skoldspuppy wrote:

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Talentco

Hey Im in Lauderdale, take it in to the honda dealership take it to Coral Springs Honda if you can and have them disable the economy mode, my wifes mother has an Odyssey and she hated that feature, the dealer charged her 200 bucks to do it, since it required rewiring and reprogramming of the computer
after that your problem will be solved.. you'll just get less MPG

But thats only one idea.. im sure others will add more to this thread

Later
Skold

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Did she have it disabled because of audio issues or because she just didn't like that feature?

Velocity Motors wrote:

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Not being there the only suggestions that I have are the following:

• if in fact there is a voltage drop that would affect the performance of the amplifier when the transmissions switches from 6 cylinder to 4 cylinder, I would run a power wire from the alternator ( fused ) directly to a Optima battery designated for the audio system. This will isolate the power from the rest of the system and the affects of the voltage drop from the rest of the car
• If they used a PAC trunk LOC they would have been able to use the low level output of the OEM radio & converted it to RCA outputs.
• Make sure to test the power wire off the battery for the amplifier's to see if there is infact a voltage drop when the transmissions drops from 6 to 4 cylinders. Also test the voltage from the preamp wires on the LOC for any drop in voltage.
• Check for an absolute ground on the LOC as well as the amplifier to ensure proper grounding location.
• I'm sure they used triple shielded RCA's

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I handed the installer your ideas and they said that running a wire directly from the alternater would damage the altenater in a few months.. then I specified that it would be attached to a dry cell, they were like.. hummmmmmm maybe..

They also said that they did check the voltages while driving and that there was no flucuation in voltage output from anywhere. 

I'm taking the installer at his word when he says he did these tests while driving the car...  at this point everything has been taken out and we are not planning to re-install. 

The owner of the store was also given  a copy of your ideas and his first comments to me where, "Where did you get this?"  He liked the idea of running a dedicated line to a dry cell.  I'm contemplating letting them have another go at it.  They refunded me all of my money.

I don't know if I'm willing to have another go at it.

Do you think that the alternater stands a chance of being damaged in this scenerio?

OJ

Talentco wrote:

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Did she have it disabled because of audio issues or because she just didn't like that feature?

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She had it disabled cause she hated that featured, it would lag when she needed to jump into the throttle

Hi,

I think the noise you are experiencing is basically white noise.  Honda uses it to mask the sound of the engine when running on three cylinders.  At least that's what I heard described on Autoweek.  Not sure if the dealer can deprogram the masking feature though.  Just my two cents.

Mark

Ween]< wrote:

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>Hi,

I think the noise you are experiencing is basically white noise.  Honda uses it to mask the sound of the engine when running on three cylinders.  At least that's what I heard described on Autoweek.  Not sure if the dealer can deprogram the masking feature though.  Just my two cents.

Mark

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 Are u telling me that this white noise is audible?  Is it produced through the sound system?

The freakiest thing about it all is that we got the feedback even when the stereo power was off.

The sub and amps were triggered by the ignition...

Talentco wrote:

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Do you think that the alternater stands a chance of being damaged in this scenerio?

---

The alternator will probably get damaged over time if you directly wire the power wire to the amplifier's. The amperage draw would be too much for the stock alternator to handle. The idea of having a secondary battery was to isolate the stereo from the rest of the electrical system & also supply the required power to the audio system without straining the OEM system. Glad he liked some of my ideas, but in the end, you'll have to see if the isolation method works. In my mind it does, but your still feeding off the audio preamp signal and this maybe the problem. As long as he probed the wires while driving and deduced that there was no problems on the preamp signal going into the PAC module, then I would start looking elsewhere, but I would get a second reading on that preamp signal if all else fails.

more info....honda active noise control

https://www.google.com/search?hl=en&ie=ISO-8859-1&q=honda+active+noise+control&btnG=Google+Search

Even though the stereo was physically off via the power switch, i bet the speaker outputs still have signal (masking noise) on them, hence the output you have is just being amplified by the equipment you added. 

Ween]< wrote:

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>

Even though the stereo was physically off via the power switch, i bet the speaker outputs still have signal (masking noise) on them, hence the output you have is just being amplified by the equipment you added. 

---

Great system that ANC !! The only thing that I can see being a problem is that OJ mentioned that the problem still persists with the radio off and the ANC activates only in 3 cylinder mode. Now what we need to know from OJ is when the feedback occurs, is the engine running ( idle ) or with the key in the ON position, but not started ?

Another thing is, does the van engage the ANC feature right off the bat from idle or does it start in a 6 cylinder and then drop down to 3 cylinder's after it idles for XX amount of time ?

Ween]< wrote:

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>more info....honda active noise control

https://www.google.com/search?hl=en&ie=ISO-8859-1&q=honda+active+noise+control&btnG=Google+Search

Even though the stereo was physically off via the power switch, i bet the speaker outputs still have signal (masking noise) on them, hence the output you have is just being amplified by the equipment you added. 

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How bout them apples........... Thanks WEEN

Active Noise Control

A feature found in many luxury cars, Honda's Active Noise Control was specified for Accord Hybrid to counteract the extra noise created by the imbalanced motion of the car's V-6 engine when the VCM system deactivates the rear engine bank's three cylinders. In this condition, the booming noise of the engine is more spread out, and thus more noticeable to the naked ear.

The ANC uses input from the engine's ECU and microphones in the cars interior - one mounted in the front headliner and one in the rear parcel shelf - to monitor noise levels in the passenger cabin. When the ECU puts the i-VTEC V-6 engine in 3-cylinder mode, a control unit synchronizes the booming noise created with an opposite phase signal sent through the car's audio system to essentially cancel each other out. The result is an audio signal with an opposite wave and a very quiet interior. ANC works whether the radio is on or off.

The Active Noise Control is only active when the engine is in 3-cylinder operation, and operates regardless of whether the audio system is on or off. The microphones are tuned to only recognize the engine booming noise - passenger's conversation, the audio system, or excess road noise have no affect on the system.

Now I just need to find out if this is also true in the Odyssey

Velocity Motors wrote:

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Ween] wrote:

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Even though the stereo was physically off via the power switch, i bet the speaker outputs still have signal (masking noise) on them, hence the output you have is just being amplified by the equipment you added. 

---

Great system that ANC !! The only thing that I can see being a problem is that OJ mentioned that the problem still persists with the radio off and the ANC activates only in 3 cylinder mode. Now what we need to know from OJ is when the feedback occurs, is the engine running ( idle ) or with the key in the ON position, but not started ?

Another thing is, does the van engage the ANC feature right off the bat from idle or does it start in a 6 cylinder and then drop down to 3 cylinder's after it idles for XX amount of time ?

---

I definitely never noticed it when it was in idle or when the van was turned on.  In fact it seemed to occur mostly after the van was warmed up and only when the van went into ECO mode. 

After reading the link "WEEN" posted, I think we found the root of the problem.  Now if there were anyway to disengage that noise cancelation feature, then we'd be on to something.

here we go:

In fact, the Odyssey models with VCM are especially quiet because those vehicles are equipped with Active Noise Control (ANC) technology that works with the audio system to effectively cancel inherent noise produced by the VCM system (along with some road noise). Additional NVH dampening occurs through the use of an Active Control Engine Mount System (ACM) that uses electrically activated dampers to minimize engine vibration for an incredibly smooth and quiet driving experience.

That's gotta be it!

Yep thats it, take it to the dealship and order them to disable it

Talentco wrote:

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here we go:

In fact, the Odyssey models with VCM are especially quiet because those vehicles are equipped with Active Noise Control (ANC) technology that works with the audio system to effectively cancel inherent noise produced by the VCM system (along with some road noise). Additional NVH dampening occurs through the use of an Active Control Engine Mount System (ACM) that uses electrically activated dampers to minimize engine vibration for an incredibly smooth and quiet driving experience.

That's gotta be it!

---

Boy that's alot of acromyns going on there. You almost have to have a PH.D or have a P. ENG to understand some of those HTDA ( hard to decypher acronyms ) 

skoldspuppy wrote:

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Yep thats it, take it to the dealship and order them to disable it

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I'm going to call them now....  SKOLDSPUPPY..  I imagine that you don't have a contact to the mechanic in Coral Springs who did that job for your in-law.  If u happen to then I would appreciate the contact info.  I guess it's best for me to go to the Honda garage and speak to the mechanic directly.  We'll see.....

Talentco wrote:

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I'm going to call them now....  SKOLDSPUPPY..  I imagine that you don't have a contact to the mechanic in Coral Springs who did that job for your in-law.  If u happen to then I would appreciate the contact info.  I guess it's best for me to go to the Honda garage and speak to the mechanic directly.  We'll see.....

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As Soon as my mother in law gets back from her gambling trip to vegas I'll get you the name of her service advisor, she's back on tuesday

Later

Thanks SKOLDSPUPPY...

I called the honda mechanic here in town today and he didn't know about that feature..

He welcomed me to come and find out about it in their service book then they would work from there..

they were really busy when i called... I'm thinking about just forgetting about the whole thing all together...

I will post if I do decide to.... and let the board know of the outcome

Talentco,

I had this same problem. Fortunately for me, the shop foreman at my local Honda dealer (Keyes Honda, Woodland Hills, CA) was very helpful. He went online to Honda's website and accessed the wiring schematics for the Active Engine Mount system which is the system that sends the audio feed to the Active Noise Control system and the audio system. He found the one wire that sent this signal in a wiring harness that is right above the parking brake (pictured below). Unfortunately, he was the one who did the work and didn't show me exactly which wire he clipped, but I am sure if you took this picture to your dealer and this post, they will be able to locate the wire in the schematics and clip it. I am pretty sure it was a pink wire. This immediately solved the problem. As a side note, we test-drove the van afterwards and even with the stereo off, I could hear no odd noises when the ECO mode activated. I think the ANC is more of a gimmick then an actual necessary feature of the van.

I hope you will use this info and re-install your system. It is definitely worth it! I also installed an 8" JL sub in an old enclosure I already had. It fit nicely under the center tray between the front seats.

.....................

Jason,

Thanks for the great post and picture...

I'm assuming you ran into the same feedback in your JL sub as I did...

Did you update everything?  What did you update to besides the JL 8"

Thanks
OJ

..........................

I was on a pretty tight budget, but I HAD to do some minimal upgrades. Surprisingly, the sound is decent and the volume can go fairly loud without distorting even though the speakers are running off the head unit.

Removed the plastic tray under the front passenger's seat and installed the Alpine amp in it's place. Two screws holding it in place, all controls are accessible.

This picture is taken from the passenger's door, leaning in towards the dash so you can see the front of the 8" JL Microsub. You can't really see it when sitting in either front seat unless you lean forward and are looking for it. I also usually have a big 150 cd wallet leaning in front of it blocking the view completely.

The sub BARELY fits under the tray. I used a small block of wood to prop up the left side so that the sub isn't extending out of the box and hitting the carpet. Not a perfect match for the interior, but not too bad either considering I bought it in '95 and this is the 3rd vehicle I have installed it in.

I didn't take any pictures of the upgraded speakers as the grilles don't really show much.

Equipment list:

Front Speakers: Infinity 6002i 2-way $59.96
Rear Speakers: Kenwood 3-way KFC1679IE $39.99
Subwoofer: 8" JL Microsub (already owned)
Subwoofer Amplifier: Alpine MRPT220 $89.99

I got pretty big discounts on all of the equipment because I had just been to Circuit City and told the guy at Good Guys the total price they had offered. They didn't have the exact same models for everything, so he picked the closest matches and then discounted away until he got to the price I had given him from Circuit City.