2006 A4 Avant Build.

[naiku]

Do it! We won't tell

Are you spying on me?


3 different ground locations, all made no difference. Optical cable disconnected made no difference (and a little disappointing but the door that covers the optical port broke off when I unplugged the cable. I liked how snugly the cable went in, now it feels a little loose). I have not tried a ground direct to the battery as I don't have enough wire laying around to try. Pretty annoying at the moment.

[claydo]

Boo, Ian, hate to hear your having noise issues from your new toy. That'll kill some excitement fo sho.......hope maybe you can use yer gain structure to quiet it to tolerable levels......not sure what else to suggest as it sounds like it's inherent to the unit, being it quits when ya mute it. Good luck!

[naiku]

Thanks Clay.... it really sucks as the noise is pretty loud to be honest. It's not noticeable while listening to music, but I hate that its there. May look into an internal input sensitivity setting to the unit, but I am using optical so not sure it makes a difference. Messing with the gain structure may be the only option I have, at least I have 50% of the gain still available at the amps, as well as the MiniDSP being 6V outputs may mean I don't lose much if any volume.

The other weird thing is I must have really screwed up level matching or TA... this could be down to the beer in the cupholder.... but, with the Helix it was sounding pretty good. First time I punched settings into the MiniDSP it pulled to the left so much I had to check the right speakers were even working. For now just used the tracerite website to get some TA values using the EQ setting and get things somewhat improved. But, I may reset and start over especially as I seem to have lost both width and some height. Weird how just swapping one thing really messes you around!!

I tell you one thing though, exporting PEQ values from REW and then importing into the MiniDSP is cool and a nice time saver!!! Hoping to get everything sounding good before I throw rear speakers into the mix.

[BigAl205]

Messing with the gain structure may be the only option I have, at least I have 50% of the gain still available at the amps, as well as the MiniDSP being 6V outputs may mean I don't lose much if any volume.

Did you go back thru and re-adjust gains after it was installed? Going from a processor with 4v out to one with 6v out will definitely change things.

[naiku]

Did you go back thru and re-adjust gains after it was installed? Going from a processor with 4v out to one with 6v out will definitely change things.

Not yet, it is something I need to do though. Might actually do that later, although I suspect it is not going to cure the hiss, it is something I do need to do.

Edit 1: OK, just got done checking gains. I think I could have left them alone to be honest, trying to set them by ear before I started to notice any distortion it was way louder than I would listen to it. Left all of them at 50%. The exception being the sub, which did make some not so happy noises at higher gain so I dialed it back down to about 40% (could have also left it at 50%, but figured I would err on the side of caution). Rear speakers are also less than 50%.

As for the hissing noise.... at the moment I am leaning towards saying screw it. Getting a tune on there I am happy with and enjoying it. With music playing I don't really notice it, for the next few months it is going to be miserably humid in the garage to spend much time on it and I would rather enjoy it than chase a hissing noise that may never go away.

So, here is something I am having a hard time wrapping my head around. If I enter measured TA values into the DSP software, the left is so much louder than the right you would think I forgot to connect the right speakers. If I use the tracerite.com/calc website and use the EQ method it pulls things into the center much better (before even level matching, which going from memory of the Helix the left was only ever set 1-3db quiter than the right). In fact, looking in the MiniDSP software this seems backwards.... here are the tweeter values:

Left - Distance = 71.72cm, Delay = 2.085ms
Right - Distance = 121.95cm, Delay = 3.545ms

Call me crazy, but should the closer tweeter not have the larger delay? It is the same story with mids and midbass, despite the left being the closer driver the delay is larger than the right. I am second guessing myself that I have the L and R mixed up on the routing tab, but 99% sure I have them correct. Even if I have those backwards though, should the closer speaker not have a larger delay?

Edit 2: Ok, to make sure I was not going nuts I entered my measured values into the tracerite.com/calc site and sure enough, the closer speakers have the longer delay. Just to be really certain, I reinstalled the Helix DSP PC tool and entered the values there, yep, closer speakers get a longer delay. For some reason the MiniDSP software is not working correctly when I enter the measured values.

Edit 3: So entered the values that are correct, per both Helix software and the tracerite website and sure enough, sounding good. Looks like a bug with the MiniDSP software. Now, onto trying to get the rear fill dialed in and then some PEQ. Once that is all done, I may go back and try to figure out the damn hissing.

Edit 4: Apparently the way the MiniDSP software works is that if you are using distances, you enter the distance you want to virtually add and not the actual measured value. For example if your right mid is at 3ft and your left at 1ft. You have to calculate the difference (3ft - 1ft) and then the resulting 2ft is what is entered in as the distance into the DSP plugin. Seems a really odd way of doing things compared to every other DSP I have used, what's worse is it not mentioned in the manual. It just says you can enter a time or a distance into the time delay.

[naiku]

Spent a little time tuning today... Sounding pretty damn good already. The stage is a little off to the right, like 4" or so, should be a simple enough fix though.

Rear fill is up and running, not sure yet if I am getting the most out of it currently. The stage sounds further out, however, I may have lost a little width. If I mute the rears not much changes, so I think I need to tweak the settings. At the moment they are delayed 22ms and playing 500-3000hz, -4db in the mini DSP routing tab.

The hiss is still there, not sure what to do about it yet. I don't compete and it's not really noticeable while listening to music. So I may leave it. But, I would like to compete just a couple times for my own curiosity and that hiss will likely skew any results.

[naiku]

Decided I cannot stand the hissing noise, on some quiet parts of songs you can clearly hear it. So, trying to figure out the cause.... here is everything I have tried so far....

3 different ground locations in the trunk - No change
Grounded directly to the battery - No change
Toslink disconnected - No change
Wired remote disconnected - No change
Tablet PSU disconnected - No change
Reduced volume at DSP to the point I could hear no music - No change in level of hiss
Reduced input gain in the DSP software on the Toslink as low as it would go - No change
Reduced output gain on the tweeter channels (tweeters are most noticeable, so using those as the guinea pigs) in the DSP as low as it would go - No change
Ran a 3.5mm to RCA from the USB DAC direct to the tweeter amp (bypassed the DSP) - Virtually no noise, you have to press your ear to the tweeter to hear any at all. However, the USB DAC is 2Vrms out vs the 6Vrms out of the MiniDSP.
Checked gains at amps - No change (amps are at 40-50% gain).
Changed input sensitivity - No change - I suspected this would happen as the input sensitivity does not affect the Toslink input, but figured I would at least try it.

Here is what does get rid of the noise...
Output RCA's disconnected - Complete silence
Muting the volume either via DSP remote or software - Complete silence

Just got back inside from lowering the tweeter gains to just a little under 1/4, I also went ahead and lowered the mid gains a little as well. Left midbass and sub gains as is for now (much harder to get to that amp). There is still noise present, but assuming I have not lost too much overall volume I may be able to live with it. Gonna try to find time later to listen to a bunch of stuff and make a decision.


Here is a quick video, there is some background noise, but you can clearly hear the hiss from the DSP. The clicking is me muting/unmuting via the remote. May try to get a better video later this evening with less background noise.

https://youtu.be/gLqajH0jPEc

[subwoofery]

Capacitor doesn't get much love but it can solve your problem.

Kelvin

[naiku]

OK, so I just got back from listening to a bunch of music. I think I can live with it... I may dial the tweeter gains down a little more just to take some more of the noise/hiss away but overall volume is still good and loud. Certainly it gets loud enough for me to not be concerned about it, sure it's not Clay loud, but I also don't go around scaring random ladies out on a walk with their family!!

At some point I may revisit things, but I have read a few accounts of people getting noise with the MiniDSP 6x8 so suspect they may just be a little noise prone.

[JayinMI]

...sure, it's not Clay loud...

But what is, really? lol

Jay