Mini dsp questions

D1PP1N

I've been messing with my mini dsp on the same build I've been working on the passive and so far these are my settings in the pics. The FR graph looks great on measurements but the woofer has some funky stuff going on where it distorts and has a definite buzz to it. I'm not certain what is causing it to do this. I had one minidsp running my passive mains and the other 2 channels running my subs and it worked flawlessly. For some reason when try to go full active it doesn't like it. I have a 50uf npe cap on my tweeter for safety but that's the only passive parts. 

I haven't changed the parametric eq at all. But lowered the tweeters output by -6 db. Just to try something different I tuned it flat with the parametric eq and barely changed the output eq for woofer and tweeter. It did something similar with the buzzing. Any ideas to what is happening?

PWRRYD

3 questions:
What amps are you using (and are they grounded)?
What are you using to power the MiniDSP?
Does it only do it when your laptop is connected via the USB cable and the laptop plugged into the AC brick?

D1PP1N

I am using my apa150 Dayton amp. I have a USB hub for the mini dsp that is plugged into the wall. I also tried it from my pc as well and still has the same issue.

There are both plugged into a nice surge protector (3 prong), the amp is 3 prong power too. The minidsp is using the usb powre from a 4port usb power hub.

D1PP1N

Ok, i tried using a phone charger for the usb power instead of the hub and it had the same issue.

PWRRYD

Ok so that's not it.

ani_101

The only time I had the buzz was when plugged into the laptop.

ani_101

Which channel is the tweeter and which one is the mid? Also, in the crossover you have posted only  the highpass. Can you also post the low pass?

D1PP1N

channel 1 is the tweeter and 2 is the woofer. The woofer is 2000hz LR4 with a high pass at 40hz 48db to cut the sub frequencies.

greywarden

I had some SERIOUS ground loop and RF noise from my roomie's samsung TV back when I had my Leviathan system setup in Jacksonville. I had to install a Ground Loop Isolator, and then wrap it in aluminum foil and keep it as far as I could from the TV, took me about 3-4 days to get it completely figured out. MiniDSP is a great idea, but poorly implemented IMO. That being said, I'm using one at my GF's house to cross JR's LSS speakers to some subs and it sounds amazing, but it's in a rather noisy environment to begin with and she mostly listens to metal, haha.

jr@mac

I am going to begin working with Minidsp after Iowa. My trusty old Honkyo will serve well as a four channel amp.

I have the bare board, will need advice on addressing that. If it goes well, I might pony up for a bigger version.

greywarden

I'd house it in an aluminum (and if you can spring for it - copper-lined) enclosure to bring the noise levels down. Also a good, clean power supply (not a usb thingy)