North American Motoring - Navigation & Audio Input levels into HiFi amp

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Input levels into HiFi amp

Hey this is my first post on here... a few weeks ago I finally bought my first Mini! It’s a fine specimen of 2009 JCWs with 78k miles and a complete dealership service record (the 1 previous owner loved it greatly). My only complaint so far (except for the lack of a temp gauge) is the sound system... it has the 8 speaker HiFi system, which would be somewhat decent if it had more than a 2 band EQ... I am planning on upgrading the speakers and amp, but buying it took a good bite out of my wallet, so I’d like to try to improve what it’s already got. I just happen to have a JBL GTE422 11 band front and rear EQ laying around and really want to incorporate it in the factory system. I have the wiring diagrams from ISTA and read georgesimian’s post on swapping in HK speakers, but I’m not sure what level the signals going into the amp are. The EQ has both speaker and line level inputs, but since I’m trying to retain the factory amp (for now), I’d really like to be able to just route the signals through the EQ before they go into the amp. Thanks

I applaud your ambition, but that's going to be a lot of effort for no benefit. EQ isn't going to fix it. If it were as simple as that, the Harman Becker engineers that designed the system in the first place would have just eq'd it differently - there is extensive DSP shaping of the existing output from the HK amp:

Attachment 193070

That's the electrical output signal of the HIFI amplifier with a flat input signal. What you see there is all of the eq that is applied by the amplifier, along with the frequency gating (crossovers). Blue = front midrange + tweeter, Red = front midwoofer.

Ignoring all of that, EQ isn't going to be of any help to you. There isn't enough power available in the HIFI amp to do any boost, so anything you did would have to be in cut, reducing your volume output. You can't eq away non-linear distortion. And those two things are far and away the biggest issues contributing to the overall quality of the HIFI system.

Thanks! I figured that it wouldn’t be all that effective, but it’s only temporary until I get better speakers and get the amps put together. I’ll be using the EQ then, so I might as well install it and get the inputs hooked up. That graph will be useful too