I have a Sundown SAX 100.4 amplifier in my 2011 TL powering a pair of 6.5" Hertz components and a single 10" IDQ10 subwoofer and it has become evident that my amplifier is starved for power. Estimated power consumption is about 500W. The issue is I'll be listening to my stereo with the engine idling and as soon as I turn it off, the subwoofer gets nearly twice as loud. I would say nearly 10dB, so theoretically over three times more power to the amp. Has anyone else experienced this? I'm hoping the Big 3 Upgrade will remedy the issue, but I'm a little skeptical that it would help so much that it would triple the available power to my amp. I'm considering eventually getting a high output alternator but would like to start with the simple things first. I can't help but wonder if there's something with the TL electrical system that is causing this anomaly (ELD functionality?). Reason I say that is because it doesn't seem to happen all the time. One theory is that when the alternator is operating in high voltage mode (~ 13.9V) and I shut the engine off, there isn't a perceivable change because 13.9V is enough to power the vehicle systems and my stereo, but if I shut the engine off while it is in low voltage mode, I detect the difference because the amp was starving with the engine running and then has enough juice upon turning off the engine because it has the full capacity of the battery. Thoughts?

 

What size power wire did you use? The car should be given about 14.2 to the amp at idle, I have never heard of a amp getting more power with the car off. Make sure you have a strong ground also. 1 more question, where did you get your remote turn on from?

 

Yeah, me either, which is why I started this thread

The Acura TL (and apparently all Hondas and Acuras) employ an ELD sensor that monitors the vehicle's current draw and toggles the alternator between a low output (~12.5V) and a high output (~13.9V) accordingly. Unfortunately it doesn't monitor anything downstream of the battery, so the amplifier current draw doesn't factor in. My best guess is I am noticing a difference in sub output when the alternator is in low voltage mode and there inadequate current for the amp. Then when I turn the engine off, the full ampacity of the battery is available.

Yes, the grounds are all solid, and I am using 4AWG power wire. Regardless, neither of these things would cause the subwoofer to nearly double in volume upon turning off the engine. I'm thinking it's gotta be the stupid ELD circuit. I'm going to bypass it and see if that resolves it.

​​​​​​​I forget what circuit I tapped into to get the remote signal. Why do you ask?
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I got my remote signal off the red wire (pin 3) of Connector C in the driver's side under dash fuse box. It's part of the audio unit circuit.

 

Thats really strange, I have never heard of a car cutting power outside of its own circuits. I had a system in my 05 TL, but i'm sure the 4G layout is much different. The amp is getting 13.9 volts at idle?

 

Not sure what you mean by "cutting power outside its own circuits".

​​​​​​​The voltage varies according to the load that the ECU detects via the ELD sensor. For my particular vehicle, it varies between 12.5V and 13.9V.

 

Just did the ELD mod and I'm now at a steady 14.3V. Also in the process of doing the Big 3. I'm just waiting on some power wire to come in the mail to finish.

 

That's more like it...

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Glad you got it working

 

Just an update that I am still getting a substantial increase in volume when I cut off the ignition, so evidently my amp is starving with the engine running. I have a high power alternator installed (170A) and the big 3, so I don't understand what the issue is. I only have one 10" sub for goodness sake.

 

Surely someone has an amp and subwoofer in their Acura and has noticed it gets significantly louder when they cut off the ignition...

 

Well it definitely not the charging system after doing the big 3 and a 500 watt system should never "require" this to be done but good on ya for doing it anyways. Do you have the OEM amp still hooked up? Is everything running through an LOC using a post-amp signal? Whenever I hear of huge fluctuations of power its the source of signal or it's the component itself such as the input stages on your amp. The latter is not typically the case but can fail just like all other electronics but I would start tracking this problem starting at the amp stage and move toward the HU. IF you find a OEM amp between your aftermarket amp and the HU then you should remove it from the signal chain unless it totally necessary. The LOC, if you are utilizing one, can be the culprit as well but my money is elsewhere.

 

The factory amp is completed disconnected and removed and I am not using an LOC. I am tapping directly into the output channels of the head unit via the OEM amplifier input connector/harness. Perhaps it as something to do with the VSC feature of the head unit? I turned it off though.

 

At this point, I would recommend trying another amplifier just to compare outcomes. I know it's the last thing we all want to do but you have to eliminate the obvious.

 

I'm curious if it could be a Bluetooth thing. I am typically always listening to content via Bluetooth when I turn the car off. Except it not happening every time is puzzling. So irritating.

 

Noise cancelling microphones in the ceiling? Did you disconnect them? I just started researching upgrading the subwoofer in my TL. This is something I saw somewhere on the net, that they need to be disconnected for an aftermarket system to work properly. Where did you mount your sub? I'm a fan of ID subs. Thinking about a ID8 infinite baffle in the package shelf. The factory woofer is anemic...

 

I didn't realize there was such a thing. This is a 2011 Non-nav, non-tech.

 

https://www.google.com/search?client....0.rv1QsXQjIIg


ANC: Active Noise Cancellation.

 

That doesn't help. I can't find a reference to active noise cancellation on the 2011 TL non-nav/non-tech. The manual makes no mention of ANC. The only microphone is the one inside the front dome light for the bluetooth.

 

]Active Noise Control (ANC) and Active Sound Control (ASC)

Key contributors to the TLX's quiet, refined interior are Active Noise Control (ANC) and Active Sound Control (ASC). The two systems are comprised of dual overhead microphones, an ANC/ASC electronic processor, and the audio system's speakers. ASC/ANC operates whenever the engine is running, even if the audio system is turned off.

ANC is designed to reduce low frequency sound in the cabin caused mainly by the roughness of the road surface. The overhead microphones pick up sound waves and send them to the ANC/ASC processor, which creates and sends a precisely timed "reverse phase" audio signal to a special amplifier. In turn, the amplifier drives the door speakers to cancel the original noise signal.

ASC is a related technology designed to improve the engine sound quality by making the sound pressure level more linear as the engine revs increase. Typically, engine noise doesn't increase in a linear way with rising revs; instead there can be many resonances that create peaks and valleys in the sound pressure level and an uneven sound. ASC helps smooth out the engine sound by creating a same-phase or reverse-phase sound signal as needed and sending it to the speakers. Though the system offers benefits from idle to redline, it makes the largest difference in the range between 1400 and 2400 rpm (V6) and 1000 and 1800 rpm (4-cyl.), where it lowers the sound pressure level with a reverse-phase audio signal.

ASC is part of the Integrated Dynamics System (IDS). When the IDS is in ECON or Normal mode, the ASC system is tuned for a smooth, unobtrusive engine sound. When the IDS is switched to Sport or Sport+, the TLX's interior engine sound takes on a more aggressive note.

 

I assumed it was in all Acuras

 

Thanks, but again, I have a 2011 TL, not a TLX

 

I highly doubt that.

 

Sorry man, just trying to help.. I came here looking for where guys are tapping into the woofer channel for aftermarket sub. Still trying to figure it out. Where did you mount your IDq10? Thanks

 

I appreciate it. It's the closest I've been to a potential cause.

I mounted it in the truck facing rearward. Custom box, which is about 8" deep and 28" wide (IIRC), so I still have a decent amount of trunk space.

 

I still suspect that there may be an ANC issue. ANC is only active while the engine is running. You say you get different results with engine off. I hear the rear MIC is in the rear dome light. Unfortunately I'm nowhere near my TL to investigate right now.

 

well

i thought since my 3G had it, yours would too.. My bad!

I got nothing then

 

I'll check the rear dome light as see if it has a mic. Is there an explicit reference to ANC in your 3G manual? I don't see it, which is odd. You'd think it would at least be mentioned.

 

I guess, I eat crow... A little googling, 3G and TLx has it, but not 4G.

 

I'm wondering if it could be tied to Bluetooth. That is all I really listen to, so it's difficult to say. I'll have to start switching to the radio just before I cut off the ignition to see if it does the same thing. The radio is quite a bit louder than the Bluetooth for some reason.

 

Ok so what about the other sources like USB? Do you encounter the same problem?

 

Same thing happens with AM/FM radio.

 

+1 why hasn't this been done yet

 

...because I don't have another $500 amplifier laying around. And I find it hard to believe an amplifier would increase its gain when there is less voltage on the input rail. I have an Audio Control DQDX pre-amp as well, so I could start with bypassing that.

 

go back to stock to rule it out then. You need to start taking out all the variables to properly troubleshoot the problem..

 

Yes that's a good place to start and I would have recommended that if I knew you had a pre-amp processor. Also, you're right I find it hard to believe that an amp would behave badly out of the box but it's electronics and nothing surprises me anymore especially when it's assembled overseas.

 

I really do think it's your processor at this point especially after reading this. At one point the Audiocontrol guy offers some potential solutions that may be of help. My guess is that if you're using the OEM head unit then you are going to want switch the jumpers to balanced to start and see if it makes a difference. Then proceed to change the ground isolation switch if appropriate.
AudioControl DQDX install issues - Car Audio | DiyMobileAudio.com | Car Stereo Forum

 

Just found your thread I recently did a full system install in my 2009 TL https://acurazine.com/forums/4g-tl-a...nstall-971936/ I thought I was crazy I noticed the same problem subs are louder with the car off than at idle.

 

hows the battery? IF it's not able to discharge enough power for the engine and the audio system it can be causing issues.

 

Both the alternator and battery are brand new, high capacity. The issue existed before I replaced them, and was the very reason I replaced them.