MiniDSP vs DCX2496 - AVS Forum
Forum Jump: 
Reply
 
Thread Tools
post #1 of 75 Old 12-14-2012, 07:51 AM - Thread Starter
Senior Member
 
kcnitro07's Avatar
 
Join Date: Jul 2011
Posts: 301
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 13
Good morning everyone.

I recently acquired a miniDSP and have hooked it up and played with it for a day or so. I'm not very happy with it so I'm contemplating picking up a DCX-2496. Would this be any better?

The reason I don't like the miniDSP is I have to turn my SW out way up in order to get output, it doesn't sound near the same across the board as when using a MIC 2200. The subs start making more bad sounds at lower levels than when I was using the MIC2200 it seems. I've only used REW on this, not omnimic, which is what I used when playing with the MIC 2200. Other things I've looked at are the MIC2200 and the Feedback Destroyer. Any opinions would be greatly appreciated. Thanks.

kcnitro07 is offline  
Sponsored Links
Advertisement
 
post #2 of 75 Old 12-14-2012, 07:53 AM
AVS Special Member
 
brian6751's Avatar
 
Join Date: Mar 2006
Location: Canton, MI
Posts: 3,253
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 94
Are you using a pro amp? Which version of minidsp do you have? Balanced or unbalanced?

Xbox One Gamertag = The Barbeerian

PS4 PSNID = The-Barbeerian
brian6751 is offline  
post #3 of 75 Old 12-14-2012, 08:27 AM
AVS Special Member
 
Wrager's Avatar
 
Join Date: Sep 2002
Location: Acworth, GA
Posts: 1,282
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
I have had both and removed/sold both. I couldn't get the signal level up on the minidsp either (balanced). Wiring the phoenix connectors was a PITA too. The 2496 bricked on me when I did a firmware update. They replaced it and I sold it. Now I have a QSC DSP-30. Hopefully I will finally be succesful with my disparate subs. I just got it yesterday.
Wrager is offline  
post #4 of 75 Old 12-14-2012, 08:43 AM - Thread Starter
Senior Member
 
kcnitro07's Avatar
 
Join Date: Jul 2011
Posts: 301
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 13
I have a epx4000 consumer...rcas only, yay. balanced miniDSP.

kcnitro07 is offline  
post #5 of 75 Old 12-14-2012, 08:48 AM - Thread Starter
Senior Member
 
kcnitro07's Avatar
 
Join Date: Jul 2011
Posts: 301
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 13
Quote:
Originally Posted by Wrager View Post

I have had both and removed/sold both. I couldn't get the signal level up on the minidsp either (balanced). Wiring the phoenix connectors was a PITA too. The 2496 bricked on me when I did a firmware update. They replaced it and I sold it. Now I have a QSC DSP-30. Hopefully I will finally be succesful with my disparate subs. I just got it yesterday.

What does the QSC gain you over the others? Other than originality biggrin.gif

kcnitro07 is offline  
post #6 of 75 Old 12-14-2012, 09:31 AM
Advanced Member
 
cookieattk's Avatar
 
Join Date: Jun 2011
Posts: 524
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
Liked: 56
Quote:
Originally Posted by kcnitro07 View Post

I have a epx4000 consumer...rcas only, yay. balanced miniDSP.


unless its really old u should be able to switch it to 2v and that should be enough to clip the amp.
cookieattk is offline  
post #7 of 75 Old 12-14-2012, 09:35 AM
AVS Special Member
 
lukeamdman's Avatar
 
Join Date: May 2011
Location: Burnsville, MN
Posts: 1,274
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 15 Post(s)
Liked: 96
I have the balanced miniDSP, miniDSP 2x4 (rev A), and the DCX2496.

Your preamp voltage output, and your amplifiers voltage sensitivity, will determine which one will work best.

For the miniDSP 2x4 revA, I'm using it with a Denon AVR-3806 with a Peavey IPR-3000 and dual Captivator subs. The Denon specs say the RCA will output 1.2v, and the IPR-3000 only takes something like .775v input for maximum output. With that info, the .9v input/output of the 2x4 works perfectly. On the Denon I think my sub output level is -3db.

For the balanced miniDSP, I'm using a Marantz AV7005 that has XLR outputs that the manual says will output the typical 2.4v for XLR, and my amps are the LG FP14k clones. The sub output level on the Marantz is at -9db...

The DCX2496 I'm not terribly happy with. While the miniDSPs don't introduce any ground noise or static at all, my DCX, and maybe there's something wrong with it, does introduce some static and hiss to the entire system. I had the turn the input and output gains on the DCX wayyyyy down to minimize the noise. It's also not helping that I'm using 108db sensitive compression drivers either.

Each will work well if the voltages for each piece of equipment are matched properly.
lukeamdman is offline  
post #8 of 75 Old 12-14-2012, 09:46 AM
AVS Special Member
 
Wrager's Avatar
 
Join Date: Sep 2002
Location: Acworth, GA
Posts: 1,282
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
Quote:
Originally Posted by kcnitro07 View Post

What does the QSC gain you over the others? Other than originality biggrin.gif

You can adjust the input sensitivity, it has a ton of pre-set memory positions acessible from the front panel ( I tune differntly for music than movies-a feature I loved on the SMS-1).
Set up is drag and drop fom pictures on the screen,,,,what else am I forgetting???? Oh and Mark Seaton frequently uses/recommends it.
Wrager is offline  
post #9 of 75 Old 12-14-2012, 10:32 AM
AVS Special Member
 
brian6751's Avatar
 
Join Date: Mar 2006
Location: Canton, MI
Posts: 3,253
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 94
Quote:
Originally Posted by Wrager View Post

You can adjust the input sensitivity, it has a ton of pre-set memory positions acessible from the front panel ( I tune differntly for music than movies-a feature I loved on the SMS-1).
Set up is drag and drop fom pictures on the screen,,,,what else am I forgetting???? Oh and Mark Seaton frequently uses/recommends it.

its also $700+ eek.gif

Xbox One Gamertag = The Barbeerian

PS4 PSNID = The-Barbeerian
brian6751 is offline  
post #10 of 75 Old 12-14-2012, 10:58 AM
AVS Addicted Member
 
LTD02's Avatar
 
Join Date: Oct 2003
Posts: 15,899
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 109 Post(s)
Liked: 831
and it is 2 in / 2 out.

another option is the dbx driverack pa+, but you only get a max of 3 peq per channel and no shelf filters.

Listen. It's All Good.
LTD02 is online now  
post #11 of 75 Old 12-14-2012, 11:26 AM - Thread Starter
Senior Member
 
kcnitro07's Avatar
 
Join Date: Jul 2011
Posts: 301
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 13
I have an onkyo tx-nr609. I'm not sure the SW out voltages on it. I tried measuring, but that didn't work so well, was saying .02...unless I had it set too low on the voltage meter and that was really 2...hmmm I don't think so...maybe I measured incorrectly...haha...

I set the volt input on the balanced dsp to .9 from 2 and it didn't make a difference. The EPX4000 input sensitivy is 1V. The Balanced MiniDSP uses 2V output, however, the input is .9 or 2. I have it at .9 and that doesn't seems to be low. Depending on what I listen to I can go to +12 on my SW without clipping the amp (thats with no EQ applied) Should I just get a signal booster and call it a day??

kcnitro07 is offline  
post #12 of 75 Old 12-14-2012, 12:05 PM
AVS Special Member
 
Wrager's Avatar
 
Join Date: Sep 2002
Location: Acworth, GA
Posts: 1,282
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
Quote:
Originally Posted by brian6751 View Post

its also $700+ eek.gif

I paid $169 for an instore demo (Guitar Ctr).
Wrager is offline  
post #13 of 75 Old 12-14-2012, 01:07 PM
AVS Special Member
 
Luke Kamp's Avatar
 
Join Date: Aug 2010
Location: Kansas City
Posts: 1,130
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Liked: 92
Do you have the gain maxed on your epx4000?
Luke Kamp is offline  
post #14 of 75 Old 12-14-2012, 02:05 PM - Thread Starter
Senior Member
 
kcnitro07's Avatar
 
Join Date: Jul 2011
Posts: 301
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 13
Quote:
Originally Posted by Luke Kamp View Post

Do you have the gain maxed on your epx4000?

Yes. I'm still trying to understand the "input/rms" meter on the mini dsp. It goes from 0 down to like -85 dB or something (i'm not sitting in front of it as I'm at work) and I have it at 0 if I go down to like -10 on it the signal level changes to -infinity. At 0 its at -75 dBfs. I had to go to +6 on the SW playing the REW test tone form 10-100 Hz before it moved from -75 dBfs....

kcnitro07 is offline  
post #15 of 75 Old 12-15-2012, 04:39 AM
AVS Addicted Member
 
LTD02's Avatar
 
Join Date: Oct 2003
Posts: 15,899
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 109 Post(s)
Liked: 831
looks like the driverack px can be had for $350.

it is 2 in 4 out and has 3 peq that can be setup as shelf filters. might be an alternative.

Listen. It's All Good.
LTD02 is online now  
post #16 of 75 Old 12-15-2012, 10:00 AM
AVS Special Member
 
Stereodude's Avatar
 
Join Date: Jan 2002
Location: Detroit Metro Area
Posts: 9,664
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 331 Post(s)
Liked: 384
Quote:
Originally Posted by kcnitro07 View Post

The reason I don't like the miniDSP is I have to turn my SW out way up in order to get output, it doesn't sound near the same across the board as when using a MIC 2200. The subs start making more bad sounds at lower levels than when I was using the MIC2200 it seems. I've only used REW on this, not omnimic, which is what I used when playing with the MIC 2200. Other things I've looked at are the MIC2200 and the Feedback Destroyer. Any opinions would be greatly appreciated. Thanks.
How do you have the jumpers inside the MiniDSP set? How high are the gains on your amps? How loudly do you normally listen?
Stereodude is offline  
post #17 of 75 Old 12-15-2012, 10:55 AM
AVS Special Member
 
Luke Kamp's Avatar
 
Join Date: Aug 2010
Location: Kansas City
Posts: 1,130
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Liked: 92
I have always left mine on 0 and don't have the balanced or proamps so I am little to no help here. Maybe your power supply to the minidsp isn't fully powering it? I saw somewhere that someone's Onkyo receiver was acting up and everything worked after a system reset. Are you using input one to output 1 and 2? Maybe try input 2 and output 3 and 4 if thats the case. The balanced is supposed to put out 2 volts. Good discussion on which one to get here.

http://techtalk.parts-express.com/showthread.php?225681-Which-MiniDSP-to-get

You had an issue with the mic2200 here, I really think you need to figure out what is going on in your signal chain/gain structure before getting different eq, as the problem may keep following you.

http://www.avsforum.com/t/1415823/2-dayton-titanic-mk-iii-15s-or-1-tc-sounds-lms-r-15/90

Best of luck, wish I was more help.
Luke Kamp is offline  
post #18 of 75 Old 12-15-2012, 02:24 PM
FOH
AVS Special Member
 
FOH's Avatar
 
Join Date: Apr 2010
Location: Midwest
Posts: 4,742
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 11 Post(s)
Liked: 207
The idea of loudspeaker DSP gear is the way to go. It's exciting to see so many looking into and experimenting with such an approach.

Multiple subs is clearly the path to bass bliss, ..... and managing them can become unwieldy. The automated systems are nice, but not as accurate and effective as manually dialing everything in.


I recently completed a search for a new loudspeaker/subwoofer dsp processor.
Bringing experience with loudspeaker processing of this type from the pro/live sound world, it only made sense to go with a full blown processor for my home audio system/HT needs.

I really like what miniDSP is doing, but it seems every piece they offer had an element I didn't want.

I like the idea of the highly capable pieces, wih enough channels and adequate transparency for LCR mains processing as well. So that meant at least 4 input channels, at that point, they typically come in 4x8, or 8x8 configs. If I needed more than four total channels of processing, the subwoofer, and LCRs, I'd need all the channels. That would be 8 inputs (7.1). However, on the output side, I'd not have enough channels,...so why pursue it? After all 7 speakers and 1 sub, there's no outputs left for multiple subs. And that's the primary point of the entire exercise, managing a multi-sub system.

So, for me there's no point in going past 4 inputs,...so a 4x8 it is. If it has enough transparency and I route the LCRs thru it, then on the output side, there's enough for 5 subs. I targeted four total subs, and I'd planned on eventually integrating a tactile transducer system, and time alignment and low pass control are vitally important for a more seemless transition.

Anyway, I really like the Xilica products, especially the Xilica based Sabine 4x8. Sabine is a small company. It's my understanding Sabine takes Xilica products, tweaks them, re-writes the GUI, sells them as their own. Most of all, I really like their user interface the best. Their thru-put fidelity comes highly reccomened. They've got 6 parametric filters on both input and output sides. As one can imagine, there's a ton other useful features, which are pretty standard throughout the industry. I like the full size XLR connectors on everything untl the 8x8, where there's just not room. The problem is they're custom built, delivery times aren't what they advertise.


The Behringer DCX seems like a solid offering. Some say it is not as user friendy as other gear, but I know many that really love what it offers for it's price.

The miniDSP offerings are suely becoming more and more prevalent, with many happy users and an actively expanding product line.


Thanks

------------------------------------
Flat, Deep, Clean, Linear, and Loud
------------------------------------
Active 16.8kw, 7.3 system
(3)Seaton Cat12C up front, (4)QSC K8 sides/rears
(2)Seaton SubM-HP, (4)18" IB
FOH is offline  
post #19 of 75 Old 12-15-2012, 04:03 PM - Thread Starter
Senior Member
 
kcnitro07's Avatar
 
Join Date: Jul 2011
Posts: 301
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 13
Does anyone know the output voltage of the Onkyo txnr609?

kcnitro07 is offline  
post #20 of 75 Old 12-15-2012, 04:33 PM
AVS Special Member
 
Stereodude's Avatar
 
Join Date: Jan 2002
Location: Detroit Metro Area
Posts: 9,664
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 331 Post(s)
Liked: 384
Quote:
Originally Posted by kcnitro07 View Post

Does anyone know the output voltage of the Onkyo txnr609?
Not sure, but the MiniDSP will output the same voltage it gets unless you adjust the input and output level trims in the software (if you have the jumpers set to 2.0V) until you clip it at 2.0V.

Can you post a picture of your wiring harness?
Stereodude is offline  
post #21 of 75 Old 12-16-2012, 08:09 AM
AVS Special Member
 
Martycool007's Avatar
 
Join Date: Jun 2011
Posts: 3,380
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 89 Post(s)
Liked: 142
There seems to be a huge number of people who are having trouble with the combination of AVR low subwoofer output voltage when using a Minidsp inbetween that and the pro-amp. This is making me Leary of using a minidsp, and to be honest, I am having so many issues with my DIY sub and pro-amp that I am just about ready to dump all this crap and go back to commercial offerings. Urgggg!
Martycool007 is offline  
post #22 of 75 Old 12-16-2012, 08:22 AM - Thread Starter
Senior Member
 
kcnitro07's Avatar
 
Join Date: Jul 2011
Posts: 301
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 13
Quote:
Originally Posted by Stereodude View Post

Not sure, but the MiniDSP will output the same voltage it gets unless you adjust the input and output level trims in the software (if you have the jumpers set to 2.0V) until you clip it at 2.0V.
Can you post a picture of your wiring harness?

The input and output are both at 0 and appear to only go down from there. When I was watching the rms levels on the meter it wasn't even lighting up until I got to 0 on the SW out on the receiver.

If by harness you mean the RCA I split open and wired positive to the the + and negative to the - with a jumper over to the shield...sure I can post a picture of that sometime.

kcnitro07 is offline  
post #23 of 75 Old 12-16-2012, 09:36 AM
AVS Special Member
 
Stereodude's Avatar
 
Join Date: Jan 2002
Location: Detroit Metro Area
Posts: 9,664
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 331 Post(s)
Liked: 384
Not sure what to tell you... I have my balance MiniDSP in between my receiver and a pro amp and I have plenty of output. I've used 3 different pro amps (QSC PLX2402, Crown XLS Drivecore 1500, & Crown XLS Drivecore 2500) without issue. However, I'm using an XLR out of the MiniDSP to the pro amp.

I've also used a QSC DSP30 as an EQ and own several. For straight subwoofer EQ'ing it's not quite as capable as the MiniDSP since you can't directly manipulate frequencies below 20Hz. It can do some things the MiniDSP can't like compressing and limiting, but they're not so useful when dealing with just sub equalization.
Stereodude is offline  
post #24 of 75 Old 12-16-2012, 09:53 AM
AVS Special Member
 
Stereodude's Avatar
 
Join Date: Jan 2002
Location: Detroit Metro Area
Posts: 9,664
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 331 Post(s)
Liked: 384
Quote:
Originally Posted by Martycool007 View Post

There seems to be a huge number of people who are having trouble with the combination of AVR low subwoofer output voltage when using a Minidsp inbetween that and the pro-amp. This is making me Leary of using a minidsp, and to be honest, I am having so many issues with my DIY sub and pro-amp that I am just about ready to dump all this crap and go back to commercial offerings. Urgggg!
No one should be having problems unless they have incredibly inefficient subs that require the amplifier put out full power at say -20dB below reference on the receiver and this would be a problem straight from the receiver also.

The only other issue would be at extreme playback levels if the system isn't calibrated correctly the MiniDSP could be driven into clipping before the amplifier is fully saturated. This can be solved by correcting the calibration.
Stereodude is offline  
post #25 of 75 Old 12-16-2012, 12:22 PM
AVS Special Member
 
Stereodude's Avatar
 
Join Date: Jan 2002
Location: Detroit Metro Area
Posts: 9,664
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 331 Post(s)
Liked: 384
Okay, so I put my new True RMS multimeter to use today. First, my Pioneer Elite SC-05 will output ~9.5VAC (RMS) from the SW output (+12 on the master volume / 0dB on the SW) from 0dBFS dual mono sine wave fed into it via HDMI. Second, the MiniDSP seems to run out of output swing at ~4.6VAC (RMS) on the XLR outputs. This is at around +3dB on the master volume (SW output at 0dB).

Important note: The RCA outputs have 1/2 the voltage output of the XLRs. So, if you're feeding ~4.6VAC (RMS) into the MiniDSP (via RCA or XLR) the RCA output will only have 1/2 that voltage.

I'm going to try DTS 5.1 encoded sine wave (in the LFE channel) later today to see if they're hotter (or not). My high level understanding is that they should be capable of an additional 10dB vs. dual mono sine waves though the bass management. I should probably also borrow a scope and make sure the waveforms are are not clipped at the measured voltage levels.
Stereodude is offline  
post #26 of 75 Old 12-16-2012, 05:00 PM
AVS Special Member
 
Stereodude's Avatar
 
Join Date: Jan 2002
Location: Detroit Metro Area
Posts: 9,664
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 331 Post(s)
Liked: 384
Quote:
Originally Posted by Stereodude View Post

I'm going to try DTS 5.1 encoded sine wave (in the LFE channel) later today to see if they're hotter (or not). My high level understanding is that they should be capable of an additional 10dB vs. dual mono sine waves though the bass management. I should probably also borrow a scope and make sure the waveforms are are not clipped at the measured voltage levels.
I completed my testing with various sine waves encoded in DTS and posted it here. The MiniDSP seems to have some potential issues in high output applications.
Stereodude is offline  
post #27 of 75 Old 02-22-2013, 09:05 AM
Newbie
 
drawbars's Avatar
 
Join Date: Feb 2013
Location: Ashby, MA USA
Posts: 9
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Hi All,

I'm new to this forum, but I've been a semi-pro musician for almost 40 years. I own the miniDSP 2x4 and the DCX2496, and have used both with my 'desktop PC audio system.' I say that in quotes because it's a bit beyond the typical computer audio system: a pair of Fostex NX-5A powered studio monitors and an SVS SB12-NSD sub mounted on an Auralex SubDude isolation platform. I use it for audio mixdown and personal listening, both at 'office' volumes and pretty wide open. My PC also includes an Echo Audio Mia PCI card, which provides balanced -10dBV and +4dBu analog outputs and an S/PDIF digital out.

My system is especially demanding, because I generally listen at -25 to 30dB levels, sitting 6-7 feet from the speakers, yet often crank the system all the way up when moving around between my office and lab. So, little noises that tend to disappear in the latter take center stage during the former.

I used posts from this forum as part of my decision to buy the miniDSP and SVS subwoofer, so I thought I'd give back a little to the cause, so to speak. I spent several days connecting the miniDSP and DCX to the system in various ways to get the best sound in the smallest/most convenient arrangement. Here are my thoughts, for what they are worth.

_____
SETTING UP

My starting reference was an unbalanced connection from the Mia to the stereo inputs of the sub, then out through its high-pass outputs to the Fostex monitors. The HPF outs are filtered at 80Hz, with an unknown filter type and slope; I adjusted the LPF on the sub to roughly correspond to the same frequency. Although the sub is arguably a -10dBV device, I found I could use +4dBu levels, with an appropriate cut with the Level knob. The result was pleasing, but just a little off in the mid-bass range, even with adjustments of the sub's Cutoff knob.

One of the nice things about the DCX is its real-time capability. While it certainly doesn't take long to reprogram the miniDSP, it's long enough to make objective comparisons of small changes problematic. (I can't speak for others, but my ability to hone in on minor changes with near-certainly only holds up for 10 seconds, and then only if I have no other distractions in between.) Since I wasn't worrying about noise floors and transparencies just yet, I decided to use the Behringer box to dial in the proper crossover points and coarse room EQ.

I focused on two songs for my 'coarse' tests: In the City from the Eagles' live album, which has nice drum fills to evaluate the 'snap' of the sound; and Christina Aguilera's Make the World Move, which has a boomy, intentionally obnoxious bass line that seems to love room resonances. A couple of quick tests showed the internal filters on the SVS sub to likely be LR-2 or LR-4 design. LR-8 filters tightened up the bass nicely at higher volumes. (Like many 5" studio monitors, the NX-5As get weird when driven below about 70Hz, even with some rolloff.) I also determined that while my office isn't perfectly flat at the low end, there were no glaring issues that the sub platform hadn't tamed. So, there was my starting point: 80Hz LR-8 crossovers, summed mono subwoofer audio, no additional EQ.

_____
CONSUMER ANALOG

This is where the miniDSP shines. Setting it up in 'Rev A' configuration -- a strange name, as it only involves moving jumpers -- with the Mia set to -10dBV levels, I was able to obtain a great sounding 2.1 system. By comparison, even dialing up the input gain on the DCX by +15dB left the box running at halfway open, so to speak: -10dBV = -8dBu (roughly); add 15dB and we're at +7dBu, which is 15dB below the DCX's +22dBu ceiling; thus, we give up ~3 bits of digital data. While recognizing the target marketplace (live PA), it would have been nice if Behringer provided a -10/+4 switch on the DCX, as they do on many of their other boxes.

For an all-consumer level system, the miniDSP is the clear winner. However, I found some snags in my computer-based system:
  • Running the miniDSP off a USB port produced an annoying digital -based background whine, similar to the sound of a data modem on a phone line. It was especially bad when I moved my trackball around the screen. This was a shame, since I would have liked to leave the USB plugged in to make changes over the next few days/weeks. If I didn't regularly use the system at -30dB, maybe this wouldn't be such an issue.
  • Using an external adapter (Motorola RAZR charger I had lying around in the drawer) cured this issue, but left a 60/120Hz background hum in the Fostex monitors. I'm not sure if this can be blamed on the miniDSP -- or on the -10dBV inputs to the monitors -- but it went away when I unplugged the RCA inputs to the miniDSP.
  • I had concerns (below) if consumer levels was compromising the output of the Mia.

_____
PROFESSIONAL ANALOG

I then turned the Mia up to +4dBu levels, to better utilize its capabilities. (Echo claims that the -10 soft switch doesn't result in any lost DAC bits, but it certainly moves the audio levels closer to the noise floor of the computer.) At this point, things got complicated pretty quickly ...

The miniDSP 2x4 doesn't truly have a 'pro' level setting. Rev A is 0.9V (max.) in, 0.9V out; Rev B is 2.0V in, 0.9V out. So, I could use a higher input level, but the output was still set to consumer levels. Then, we run into the second limitation: headroom --

-10dBV = 0.316V
0.9V = -0.9dB

So, there is roughly 9dB between the nominal output level and the miniDSP's maximum input, which covers transient peaks in the program material nicely. At Rev B, though --

+4dBu = 1.23V
2V = +8.2dB

Rev B only has about 4dB of headroom. I found that when at +4 settings, I had to drop the Mia's master volume by 4-5dB, or I could hear digital clipping artifacts in really loud passages. So, really, I was running at 0dBu, not +4dBu.

On the other hand, 10dB input gain on the DCX provides +14dBV nominal, with 8dB of headroom. For professional levels, one either needs the balanced version of the miniDSP 2x4, or to stick with the DCX. In my case, the built-in XLR outputs of the DCX made for a simpler connection to the monitors, and the sound cleaned up nicely -- whether from balanced wiring or higher output is unclear.

Now, the balanced miniDSP is still only $165, shipped + $10 for the software license. Right around the NAMM show, though, there were lots of dealers offering the DCX for $240-250, delivered. This brings the decision down to less than $100, while delivering some extra features (real-time control, built-in digital audio) that the base miniDSP leaves out. For what it's worth, I found the DCX's sound at high volumes slightly more 'open,' particularly on guitar-heavy tracks, although this could simply be rationalization on my part. (It's difficult to listen closely to really loud music for extended periods without losing some focus, not to mention frequency range!)

_____
DIGITAL IN, PRO ANALOG OUT

This was probably my end goal all along, since the Mia provides S/PDIF while the rest of the system is (mostly balanced) all-analog.

To achieve this goal, one needs to add the miniDIGI board to the miniDSP 2x4 Balanced, and then to be willing to build a case for the end product. I didn't want to go this route, so my results represent the DCX path only. I suppose one could also by the miniDSP 4x10HD, but that adds extra functionality at a significant price bump, which would have been overkill for my needs.

Although the DCX has AES/EBU inputs, it can accept S/PDIF data, if the cabling is rather short. I did some research on the Web and concluded that most low-end 'S/PDIF to AES/EBU adapters' are merely a decent-quality S/PDIF cable with an XLR connector substituted on one end. I decided to try a 3-foot 75 ohm S/PDIF cable and an inexpensive ($4-5) RCA-to-XLR adapter, which works very well. The Mia sound driver has a choice between 'consumer S/PDIF' and 'professional S/PDIF' -- in their words, the definition of the copy-protect bit -- and I chose Professional. The monitor outputs were direct XLR balanced at both ends, while the subwoofer used an XLR-to-RCA cable and sufficient dropping of the Level knob setting.

Other than an accidental first setting to analog inputs, the connection was flawless. Using digital data, the DCX maps it to the full range of its internal data path, so input level matching is no longer an issue. I found the DCX's internals to run *very* close to the 'rails,' and an input pad of -1dB cleared up occasional clipping artifacts in the system. The outputs to the studio monitors also run at -1dB, just in case -- I don't like to see the peak LEDs kick in, even occasionally -- while an extra -2dB of padding allows for a better match at the sub's -10dBV inputs. Overall, I'm giving up -2dB from the ideal case on the monitors, and -4dB on the subs -- 1-bit or less from the 24-bit data path.

_____
SO, there you have it. My results won't necessarily align with some readers' needs, given my unusual analog-digital mix, but it highlights some of the pros and cons of the miniDSP 2x4 and DCX2496. Overall:

  • For an all analog, all consumer (-10dBV) system with an unbalanced signal path, it's hard to beat the miniDSP.
  • For a professional (+4dBu) all-analog signal path, the results aren't perfectly one-sided, but tend to favor the DCX.
  • For a digital in, professional analog out system, the DCX really shines.


Regards,
-BW

Regards,

-BW

Bruce Wahler
bw@ashbysolutions.com
http://music.ashbysolutions.com
drawbars is offline  
post #28 of 75 Old 02-22-2013, 09:20 AM
AVS Special Member
 
jpmst3's Avatar
 
Join Date: Dec 2005
Location: Davidsville, PA
Posts: 8,115
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
Liked: 186
Welcome to AVS! smile.gif

jpmst3 is offline  
post #29 of 75 Old 02-22-2013, 11:06 AM
Newbie
 
drawbars's Avatar
 
Join Date: Feb 2013
Location: Ashby, MA USA
Posts: 9
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Thanks! Kind of a whirlwind intro, I know. At least, you know I'm not a lurker! wink.gif

Regards,

-BW

Bruce Wahler
bw@ashbysolutions.com
http://music.ashbysolutions.com
drawbars is offline  
post #30 of 75 Old 02-22-2013, 01:15 PM
AVS Special Member
 
coctostan's Avatar
 
Join Date: Oct 2005
Location: Indy
Posts: 1,960
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 127
Drawbars, there are a couple of advantages of the 4x10HD over the DCX2496 for digital in. It offers remote volume control so a preamp is not needed and you get full digital resolution. There is a kit to add this functionality to the DCX but it requires modding the DCX and runs the price up to the same point.

The other main advantage of the 4x10HD is that you can use the analog and digital inputs and switch between them with the remote. With the DCX you have to choose either analog or digital or switch cables.
coctostan is offline  
Reply DIY Speakers and Subs

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off