Is anyone using the MS-8's internal amps in there system? If so, how do you like the sound? Differences between Headunit and AUX inputs noticeable?

I find the HU when playing FM quite harsh sounding. CD is much better, but still has an edge. My ipod playing on the AUX is good, but there's an edge to it too.

I will look at the signal with an oscilloscope soon with sinewave inputs and look for distortion, but I'm curious if I've goofed something up. I know my speakers need some break in time since they're new. For EE's, it sounds is if the output is unstable at higher frequencies and mixing badly with audio frequencies (listener fatigue). Maybe this is just class D performance....

Maybe its an issue isolated to my system.

Any ideas?

 

Thoughts:

I don't have a TSX so none of this is system specific. However, I DO have an MS8 in my Flex, and I am currently running the stock speakers with the MS8 internal amps, so maybe this will help.

There is NO harshness until clipping that I can detect. Clipping comes in a bit early but hey, 20w per channel comes quick, right?

When you do the tune, the calibration disc plays and the display will tell you if the level is too high, the signal is noisy, etc. So as long as you do that and set the maximum to this or at least close, the head unit should not clip as long as the music is less than reference dB, which it should be.

Make sure to do the sweeps with the ms8 set low, about -20 to -30dB on average. It will be quiet as it does its job. From there, up to the stop point you got on your calibration run, you should be good to go!

Don't be afraid to email Andy W. of JBL directly, he's on the http://www.diymobileaudio.com/ website. Yeah, he's that cool.

 

Thanks Fourth... I think you may right about the clipping.
During calibration, the MS-8 was set at -20dB, and the TSX HU was at 32 of 40 volume.
I use both MS-8 inputs. My Ipod (line out) uses -30 to -10dB on AUX. The HU I have been setting higher than -20dB and using less the HU volume 32. I'll try setting the MS-8 to -20dB and keeping the HU below volume 32, the proper calibration signal level.

I'm also thinking that the HU's FM signal path just isn't all that great and some of it is the FM stations' sound quality. My analog tuner at home sounds very different from station to station. 88.5, a jazz station in Seattle is one of the best sounding stations. Some sound like they just play 128kb/s MP3s.

I'll scope it too and maybe ping Andy W. like you suggested.

 

When you did your calibration with the test disc, when you brought the HU up did you encounter a "noisy" signal at any point?

 

Currently I'm running the stock fronts and rear door speakers off my MS8 and I don't have any issues with clipping or harshness. I had my MS8 at -20db and my stereo around 35 during the inputs part. Did you turn the volume down for the sweeps part? I don't remember what I set my HU volume at for the sweeps but it was somewhere around 10.

 

the hu volume does not matter for the sweeps. The MS8 is outputting directly to the speakers for those, but off the db scale on the screen.

What I'm asking is if you put the calibration CD in the car and did the calibration step BEFORE the tuning step.

 

I believe it said noisy when volume was near zero, then 'signal level low' and then signal level good/normal as volume increased.

I tried a few MS-8 volume settings during the sweeps (-20dB for the latest). I thought the sweeps originate from the ms-8 itself so the HU volume doesn't matter and could be OFF.

I have since added more midbass and bass to make the sound fuller vs. old transistor radio sound (thin). It is better. But FM radio is still the worst sounding which I would expect.

Has anyone listened using the MS-8's internal amp and then connected aftermarket amps and compared?

 

I have not but I am planning on upgrading as soon as budget allows. My system is pretty solid with the MS8 amp but there is always room to improve. In other news, on the DIYMA website Kaigoss found that if he took the sub output OFF the MS8's control and simply ran his sub amp off his main front amp's line output (and thus the MS8 ran the front as "full-range low"), the midbass of the system and the sub bass integration became incredible. See most people using an MS8 complain that the midbass is thin or lacking without significant EQ bumps. And that probably stems from the way the MS8 DOESN'T heavily mess with the sub EQ (not much to mess with really), and DOESN'T time align the sub since the frequencies we're talking about really don't need it much. After all, the phase change would only be 10-15 degrees if time aligned, and that's not likely even audible. Time alignment matters infinitely more on higher frequency points of course.

So, if you ARE amplifying your front stage, consider doing what Kaigoss suggests. It seems to be the golden ticket.

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