[Bicax]

Hi guys,

Some of you might remember that I had an MS8 + DA2 combo, and I couldn't get the MS8 to auto-tune properly without a line driver between it and the DA2 to increase the signal's strength.

I then switched to a Mosconi 6to8 V8 DSP instead of the MS8, and noticed that I wouldn't get any volume until 20 cliks on the HU (and volume overall was very low). I contacted Mobridge's technical service, and they told me that the DA2's optical signal was very low, that it was only meant to be used through RCA (not sure why it used to have an optical out in the first place then...) and that I should use the DA1 instead.

So I've bought a DA1, and now I get a lot more volume than with the DA2. However, it still takes 8 clicks on the HU before I start getting any sound, and there was a lot of noise due to the gains on the Mosconi having to be increased to compensate for the low volume (we ruled out the amps), so we've measured the voltage being output by the Mosconi and saw that it was less than 1V (around 0.7V to be precise).

Mobridge's technical service told me that the 6to8 should be outputting at least 3V.

The audio store that did the job ordered a new 6to8 to see if the issue is the DSP that I currently have installed, however seeing that I had similar issues with the DA2 + MS8 combo I'm wondering if the whole issue is caused by a defective Head Unit (my car is a 2010 LCI with iDrive)?

Has anyone had a similar issue, and what could I do to:

1) find out if the problem lies within the HU;
2) fix this issue without having to replace the HU.

Thanks

[kaigoss69]

Hello L, still tinkering around, eh? at least you are not getting bored.

To me, the common denominator here is the HU. Instead if replacing it, have you thought about completely bypassing it, either with an aftermarket HU, or by connecting your phone directly to the processor?

[Bicax]

Heya, yeah, I've been wanting to post a review of my new sound system but wanted it to be perfect, and I've realized I feel down a bottomless pit the moment I started upgrading my L7 hahaha.

I've thought about bypassing it, but my 6to8 can only connect through BT (I got the streaming module) and my phone has been giving me issues (tons of artifacts, even in another car with a different setup). Volume wise, the problem seems to be worse (meaning I get less volume even if I crank the phone up, which also leads to distortion).

Adding another HU would mean more expenses, so I'm trying to avoid that right now.

[TMR]

What da1 firmware are you using?

[Bicax]

It came with the latest one from factory, I checked it (1.5.7).

[kaigoss69]

Can you use another phone to connect to the 6to8 to see if you get a decent output through RCA? Or, can you connect a phone or iPod directly to the processor with a 3.5 mm to RCA adapter, just to make sure that the problem is isolated to the optical side?

[Bicax]

Heya,

They finally found the issue. It appears that voltage wasn't the problem, but rather the Alpine PDX amps.

They connected another HU directly to the amps, and we heard the same noise and interferences.

I replaced the Alpine with a couple of Mosconi AS100.4, and problem solved. The sound is clean, no noise, no interferences, plenty of volume.

The best part is that the sound is warm, all the harshness is gone, very dynamic and musical. And the system isn't fully configured yet!

I won't be buying class D amps again. The PDX sounded extremely cold, harsh, and unclean in comparison.

I'm totally in love with the Mosconi amps and I'm very impatient to get the car back properly tuned and EQed.

[kaigoss69]

Glad you got it worked out finally! But don't blame it on class D amps in general, you just had a bad one.

[joeyc123]

which pdx did you have? Where did you get it from? I've got a v9 and don't hear any interference unless the head unit volume is at the absolute maximum - then I hear some ticking.

[Bicax]

Originally Posted by kaigoss69

Glad you got it worked out finally! But don't blame it on class D amps in general, you just had a bad one.

Sorry about that, usually I'm not one to generalise, but I've heard a different system with Mosconi D2 amps, and similar issues appeared. In particular this "frying" sound (or "artifacts", not sure how you call it). It was definitely better than with my PDX, but still there. And the only common points between both systems were the 6to8 and the fact that the amps were class D. Then I heard a 1 series with a 6to8 and Mosconi One amps, and it was very clean.

Maybe it's due to the 6to8/class D combo, rather than the amp itself?...

Joey, I had a v6 and a v4, bought brand new from an online store. I do tend to push the volume, but not to the maximum of the HU. In any case, they didn't sound perfectly clean even at low levels.

Artifacts side, from the systems I've heard lately the sound improvement between class D amps (be it Alpine or Mosconi) and class AB was abysmal to my ears.