Comments on: Subwoofer equalization and integration with the miniDSP 2×4

By: Adam J

Adam J — Sun, 15 Oct 2017 14:19:04 +0000

Hi John – a very useful tutorial, even though I am a complete novice, I managed to get my MiniDSP working on the first try simply by following your instructions.

One issue I came across though is that the output volume is significantly reduced when connecting through the MiniDSP vs. directly. This is using the same source and volume settings on the main amp and the sub.

Is this how it should be?

By: John Reekie

John Reekie — Thu, 04 Feb 2016 11:06:40 +0000

“In effect it is your Fig 1 but instead of the Preamp would be a DAC. So I am really asking if I can substitute the Preamp with a DAC ?”

Hi Alex, you can IF your DAC (or the digital source in front of it) has a volume control, and you are able to leave the volume control on the integrated amp at a set level (say full up, so it’s acting like a power amp).

Sorry for the confusion, when I said “after the amp” I should have said “after the volume control”.

Another option to consider is the new unit announced by miniDSP at CES, which has USB audio streaming directly in.

By: Alex

Alex — Fri, 29 Jan 2016 09:41:53 +0000

HI,
Thanks for the reply.
I must admit that I’m still confused though because if the minidsp is placed after the amp how would I feed my speakers? I don’t think it has any speaker out terminals does it ?
At the moment my integrated amp feeds the subwoofer from the amps pre/subwoofer out terminals and also my main speakers via the normal speaker outs with the integrated amp fed from a DAC.
One of the functions I would like the minidsp to perform is to split the signal so that the subwoofer only receives the lowest frequencies and the main speakers only receive the higher frequencies.
I imagined the set up would be DAC to minidsp and then minidsp driect to subwoofer (after frequency filtering) and minidsp to integrated amp (after frequency filtering) to feed the main speakers these filtered frequencies.
In effect it is your Fig 1 but instead of the Preamp would be a DAC. So I am really asking if I can substitute the Preamp with a DAC ?
I hope this clarifies my problem and once again any advice would be most welcome and appreciated.

Regards Alex.

By: John Reekie

John Reekie — Wed, 27 Jan 2016 15:34:56 +0000

Hi Alex, if I understand your configuration correctly, it won’t work. You would need to put the miniDSP 2×4 “after” the amplifier. (The issue is where volume control takes place.)

By: Alex

Alex — Fri, 22 Jan 2016 18:54:33 +0000

Hi John.
Thanks for a great and informative article.
My set up is a little different from those shown.
The feed from my PC goes to an external DAC (by Toslink) and then to an integrated amp from which the pre/subwoofer out feeds a subwoofer via a dual RCA cable and the normal speaker outs feed my stereo speakers .
I am thus wondering if I can place a miniDSP 2×4 in this circuit after the DAC with miniDSP feeding the subwoofer direct and feeding the speakers via the integrated amp ?
Any advice would be very much appreciated.

By: Kirk Foster

Kirk Foster — Thu, 30 Jan 2014 22:34:43 +0000

Hi John,

Thanks for your consideration. I think I will wait for the nanoAVR as you advise. I did contact the people at miniDSP and they indicated that the nanoAVR might be released around February-March timeline.

Regards,
Kirk.

By: John Reekie

John Reekie — Thu, 30 Jan 2014 00:08:29 +0000

Hi Kirk, thanks for the kind comment. Yes, you can use a miniDSP 2×4 just on the sub line between the AVR and the sub. I had one running that way for a while. There are some limitations i.e. you have to work with what the AVR does as the high pass and low pass filters but I didn’t have too much trouble getting good integration. Having said that… well, I would wait for the nanoAVR, it will give you full control over all channels by the looks of it. Price hasn’t been announced yet I don’t think.

By: Kirk Foster

Kirk Foster — Wed, 29 Jan 2014 16:28:03 +0000

Hello John,

Thanks for a very informative article. Is it possible to connect and integrate a sub to my system connecting JUST the input of the 2×4 miniDSP to my AVR (Marantz SR 7008-Audyssey XT32 enabled) sub output.. The output of the miniDSP would then go to the input of my sub.

I would then use REW in conjunction with the UMIK1 to measure the system. Also I’m thinking that I might just wait for the nanoAVR to be released for better integration. As you might deduce I have no external amps so I need to be able to use just the AVR with a miniDSP product as I would use no pre amp—–>miniDSP—–> amp .

Thanks,
Kirk.

By: John Reekie

John Reekie — Thu, 14 Jun 2012 12:40:51 +0000

Hi Roger, I’d be more inclined to trust the sweep. One thing to check would be that you have enough signal to noise ratio, RTA tends to pick up noise more easily. I don’t know why anyone would suggest pink noise over a sweep… could you provide a link? I’ll try running a comparison in the next day or two and update.

By: Roger Roberts

Roger Roberts — Thu, 14 Jun 2012 05:34:00 +0000

I have recently purchased a miniDSP and have been using REW for about 4 weeks and both are excellent products. I have a Dayton Audio calibration mic , balanced USB preamp and both mic and soudcard calibration files have been added. I have generated a Pink Noise ( periodic noise ) CD so I can test with the RTA ( with PN full range ) or a log sweep.

Test A: Test with log sweep.
Test B: Test with RTA and PN

Each test gives very different results above about 2 kHz.

Is there any reason for this. Some articles I have read suggest Pink Noise ( periodic noise ) should be used for room EQ and not log or linear sweeps.

Any advice is appreciated.
Thanks,
Roger
Toowong Australia.