[Luigi]

Well, the miniDSP 2x4 arrived, and I had read through all the literature beforehand, but have been surprised that it didnt work for me as an active 2-way stereo crossover.

And that's probably because of user error.

Here's the problem. No output on output channels 2 and 4 so no tweeter outputs. There's  gain for both input channels, and output to both midrange units, not quite enough if Im honest, but it's as though the outputs on the tweeter are muted. And yet the mutes arent activated.

I followed set up, at least I thought I had. Anyone with miniDSP experience have any idea why there's no output in this scenario?

by the by, for midrange drivers (B200s) I used low pass at 3500, and bypass high pass.

For tweeters, I used high pass at 3500, bypass on low pass.
Cheers

P

[Redefy Audio]

hi luigi,

there's synchronize GREEN BUTTON on the upper right of the plugin. after u set the xo and eq, u need to sync them = load them to the dsp chips.

after that ur good to go 

cheers
henry

[Luigi]

Hi Henry

Thx for that Henry. Er, Im pretty sure I ve been doing all that. And even after hitting the sync button it then seems to disappear at which point any changes I make are meant to be taken in on the fly.

By the by, the gain on the two channels that do go is really not adequate in my system.

Do you know whether I can take the cover off the box and change a jumper so that I can get more gain?

So far this experience has been a bit disappointing. And the manual seems to have gaps in it. Suggesting that John's e-zine articles are the tutorials doesnt seem to sort out issues like the one Im having. And nor does the problem solving section at the back of the manual.

Urgh.

[JohnR]

Take the cables plugged into 1 and 3 and plug them into outputs 2 and 4. Do you get any sound?

[ttan98]

Hi,

I was not able to get my unit working as well initially, you need to install the latest Microsoft.Net Framework. I am using window XP pro. I think it should work wth Win 7, I am not sure.

REmove the cover you can adjust the volume output, there is 2 settings one low and the other high level output. Download the Minidsp technical manual, it will show you how to change the setting.

One way to indicate it is working is once you hit the Synch button(*), the window will come up indicating it is Synch, the Green button on top right hand corner will then disappear. If you are not getting the window it means it is NOT in Sych.

* the Green button comes on when you first power up.

[Redefy Audio]

to be more clear,

after u click on the green button, there will be a menu popup, and u need to click on the "synchronize". if u dont see this yet, means u are not communicating with the dsp.

i have very similar case for the very first time like you. u can try what ttan98 recommend though.

the green button actually for communicating to the minidsp chips.

what os do u have?  mac / win?

cheers
henry

[Luigi]

Hi Guys

Dont think the software is an issue in terms of being up to date; the fact Im getting output in two channels suggests as much doesnt it?

Im using an iMac, about a year old. Doubt the OS is out of date.

Yes, the green sync button comes on initially, I select syncronise and it downloads the data to the chip and from then on changes are made on the fly.

Thx for the info on the volume jumper. I will need to look make that change, as output currently is insufficient. In more ways than one!

Will try what you suggest JohnR, plugging 1 and 3 cables into 2 and 4. Thx for advice people. Am beginning to wonder whether this unit isn't faulty??

[Redefy Audio]

hi luigi,

i see, seems abit tricky problem 

can u describe ur system?

cheers
henry

[JohnR]

Am beginning to wonder whether this unit isn't faulty??

It seems unlikely, but you need to do some basic trouble-shooting to determine if the issue is in the miniDSP itself before jumping to conclusions. Hence my question.

[bjohng]

The solution that worked for me was to communicate directly with miniDSP.

They understand the problems we are having and use the feedback to further improve their products. They were very responsive when I had similar problems. Give them a try.

[Luigi]

An update. MiniDSP Development Team suggested I send them a copy of my .xml file to check whether the issue was with software or hardware.

They got good input levels, and all four output levels were even when plugged into a 2x4 device.

Their suggestion as to a remedy rather stunned and worried me. They felt that changing the jumpers to increase input sensitivity should correct the problem.

What a surprise when i did this. Two surprises actually. Firstly, the input meter levels approx doubled from peaks of around -60db to -30db. As did the outputs on 1 and 3, but the poor old outputs on 2 and 4 were still largely blank. The odd flicker every 10sec. Suggesting 2 times 0 is still zero.

This suggests to me the unit is defective.

As an aside, the schematic to show the 0.9v and the 2.2volt input sensitivity arrangements for the jumpers seems incorrect to me. I think they may have their pic captions labelled incorrectly. Evidently all B rev units are set at 0.9V and when I changed the jumpers to the other position the input sensitivity increased. But according to the schematic I was changing from 2.2v to 0.9v. Anyone else noticed this?

[JohnR]

 

Could you try what I suggested? You need to determine whether the issue is in the unit or in your gear.

[Luigi]

Okay, some good news I think, thanks to the Dev Team.

Im pretty sure now that the problem is all in the set up, though have not yet inserted the crossover into the system.

I did as DevTeam suggested, and made 1 and 2 channels the same with low pass at 2500, where there is now equal output, and 3 and 4 the same too, with highpass at 2500Hz and again with equal but somewhat reduced output. However, now all four channels appear to be cooking with gas!

So Im confident that with the changed jumpers and improved input sensitivity and with output to all four channels, Im back on track. Wont be able to check until Saturday, unfortunately, but Im quietly confident all will be well.

Thx all for your input. This has been and no doubt will continue to be a steep learning curve for me. Looking forward to Saturday. Again, appreciate all your helpful suggestions. Will report back soon.

[Luigi]

Update. Couldnt go away for four days without knowing. Anyway, the theory on the screen worked out when inserted into the system. Got output on all four channels now, and it even sounds promising. Actually quite decent. Look forward to messing around a whole lot more now that we have baseline success. Thx all for the help, and thanks in particular to the DevTeam who were quietly confident it was me and not their 2x4 that was at fault.

[JohnR]

Glad you got it sorted. What was the issue?

[Luigi]

Hi JohnR

Apologies for the delay in replying. Been in Australia, attending the International Motor Show in Melbourne. No that much genuinely new there, but a fun show for this end of the world.

The problem was two-fold. Firstly, input sensitivity wasn't adequate, so changed the jumpers and now getting much better output to all four channels. Also, dont think the miniDSP approved of having a crossover point so high, at around 4000Hz, from the midrange to the tweeter. Output  from the tweets was redcuced, not sure quite why.

Even as it is, at 2500Hz, which is the lowest I can go with the DE10s, there doesnt seem to be an awful lot of output from the tweeters. Having said that, Im running it with a Trends 10wpc amp, and there may be some impedance mismatches with the passive pre; I use a Lightspeed Attenuator.
The Lightspeed passive is my back up. The normal preamp is a buffered LDR passive so once that's back in the system, any day now, we should be able to have a bit more of a play. And hopefully get even better results.

[JohnR]

Hey no worries L, no new motors for me for a while but.

I think the miniDSP could care less whether you cross over at 2500 or 4000. I don't remember - do you have the ability to measure frequency response? That is really all that counts in the end.

[studiotech]

Hey no worries L, no new motors for me for a while but.

I think the miniDSP could care less whether you cross over at 2500 or 4000. I don't remember - do you have the ability to measure frequency response? That is really all that counts in the end.

I agree, the minidsp will NOT care where you crossover from mid to tweet.  There is still something funny going on. 

Greg