Here is my setting , mine is the non ML ...

 

I didn't have as much time as I'd have liked to test out settings, but I did try a few things. My observations for the ML system were as follows (Treb/Mid/Bass):

Surround: OFF
If I change the EQ settings to very high levels (+5/+5/+6), I still couldn't hear any audible signal clipping. I'm wondering if this is because the EQ (if digital) has the 'real' max level set higher than the max (+6/+6/+6) to give the EQ some bit of headroom; therefore, any EQ would actually then be subtractive EQ. It's also possible but less likely that the EQ is analog. Does anyone notice EQ introducing artifacts or distortion in their music with positive EQ values? Does it matter if it's ML vs. standard?

Also, in the case where I compared (-2/-1/0) vs (+2/+3/+4), it seemed subjectively more than just volume levels that were different. When I increased the (-2/-1/0) to a volume level comparable to the (+2/+3/+4), it seemed to me that the (+2/+3/+4) sounded better to my ears, or at least quite different. The (+2/+3/+4) sounded sharper in the treble and mids, and less recessed, even though the 'gaps' between the EQ values were the same. I think based on that, I can conclude that the EQ intervals are not 100% linear in terms of amplifying/cutting, so I don't think you can simply transpose EQ settings to get the same sound but with a different volume gain.

I have to do more side by side comparisons with equal tracks while not driving to really come to any real solid conclusions, but those were my initial thoughts with surround OFF.

Surround: ON
Yesterday, I had a curious family member test drive my car, and it was the first time that I had sat in the backseat. I noticed that with surround turned OFF, the sound from the back seats was pretty awful. In fact, almost all the audio sounded like it was coming from the rear shelf directly behind my head. It was only when surround was switched ON did the soundstage change so it came from in front of me, outputted through the rear passenger door speakers. It wasn't even a subtle change but a very dramatic difference. I think it was to the point that if I have any passengers in the car, I'll have to leave surround ON for their sake. Otherwise, the ML in the backseat sounds completely off, like you have two boomboxes sitting behind your headrest and nothing else.

From the front seat, surround ON still gives me some imaging issues where I can hear certain sounds (vocals, guitars, etc.) during complex passages of music bounce between the center channel and L/R channels, which can be a little jarring. I don't think backseat passengers have this issue, however, since they don't have their own center channel. Regardless, I'm wondering if other people have the same experience with surround ON/OFF in the backseat and whether ML vs standard matters in that case.

I should mention that this brief testing was done via an iPhone 5's Bluetooth connection with Spotify 'Extreme' quality (320 kbps) offline tracks and Auto Volume was turned off at all times, since it seems to be a compressor that could affect the sound signal quality. I haven't actually done any real testing with Auto Volume (it's always been off thus far), but it might be worth looking into whether it changes the sound. I'll also try plugging my phone in directly next time since I know BT has a little bit of compression, but I don't think changing the source to USB would change these observations. If anyone else wants me to try something specific, I'd be happy to do some more listening tests.

 

Just wanted to thank you SO much abcsoup for testing the negative EQ vs positive EQ changes and posting your thoughts on them.

Your reply was incredibly informative and very well put.

If I ever get a chance to play with an IS 350 with the ML system equipped soon, I'll definitely adjust the "Surround" settings (ON/OFF) to hear the difference it makes. I've seen this mentioned in numerous topics and I'm definitely curious to hear how drastic of a change it makes.

Once again, thank you for testing the theory out and posting your opinion on the sound quality of the system.

~ Im2bz2p345

 

[QUOTE=abcsoup;8241225]I didn't have as much time as I'd have liked to test out settings, but I did try a few things. My observations for the ML system were as follows (Treb/Mid/Bass):

Wow, great observations. I've been playing around with the surround myself. I mostly like it off but the whole passenger thing has me rethinking. I'll have to do more experimentation.

 

Bumping this up for more input

Care to share what settings you guys are using for ML and Non ML

Im currently +2 / +3 / +2 on Non ML and listen mostly to r&b and house

Going to try the negative route tomorrow

 

Thanks for the bump and pls share your negative experiment soon.
My guess is that the overall sound will be less noisy , more details and easier n relaxing to listen to