Why does my Wiim Pro + MiniDSP Flex + NC252MP sound so different to a Wiim Pro Amp

[Geertidow]

Dear forum members,

In my 2.2 setup (KEF R3 meta's with 2 x SVS-2000 pro) I've experimented the past few days with powering this system using either:

1. Wiim Pro -> MiniDSP Flex balanced -> Audiophonics NC252MP.
2. Wiim Pro Amp with an RCA splitter to split the sub out to the subs.

Reason for doing so if that if I remove 1 peak at 50 Hz with simple PEQ, I'm satisfied with the sound and I would be willing to give up that final 2% of SQ improvement for simplicity.

I have DIRAC and the whole shebang, but for the comparison I've only used PEQ with a -6dB (Q = 8) to remove a big room node.
Mains delay on the MiniDSP is 3.72 ms, on the Wiim Pro 4 ms (only whole ms can be selected).

Crossover is at 100 Hz with either a 24 db/oct LR4 roloff (Wiim Pro Amp) or Butterworth 12 dB/oct (mains) with Butterworth 24 db/oct.
This crossover was selected with the help of @OCA but of course can be varied.

The bass sounds a lot less controlled when listening the the Wiim Pro Amp (levels approximately 75-78 dB).
If I turn down the subs (note: by ear), no matter how far, it still remains greatly different.

Since we all agree that hearing a difference in amps or dacs is propably not the reason (or at least the vast majority agrees), is this only the crossover I am hearing?
I could spend some more time making some measurements, but by ear I expected much less difference then I get.

Any thoughts?

 

[kyuu]

I'm not entirely sure but the first big thing is that I assume the two subs are managed independently with the miniDSP setup, whereas with the Wiim Pro Amp only you're just splitting a mono sub signal. Typically to properly integrate multiple subs you need to be able to manage each sub separately.

 

[l_lama]

If I turn down the subs (note: by ear), no matter how far, it still remains greatly different.

Do you mean you've did audition with subwoofers powered off and still hear the difference ?
Did you SPL-match both setup with your phone or UMIK-1?

 

[melomane13]

"Crossover is at 100 Hz with either a 24 db/oct LR4 roloff (Wiim Pro Amp) or Butterworth 12 dB/oct (mains) with Butterworth 24 db/oct."
So you compare apple and oranges...

 

[Geertidow]

Do you mean you've did audition with subwoofers powered off and still hear the difference ?
Did you SPL-match both setup with your phone or UMIK-1?

I mean no matter how far I turn them down (from -1 dB on both as compared to with the MiniDSP to - 20 dB).
I have not yet level matched it, but even on low sub volumes it sounds off.

"Crossover is at 100 Hz with either a 24 db/oct LR4 roloff (Wiim Pro Amp) or Butterworth 12 dB/oct (mains) with Butterworth 24 db/oct."
So you compare apple and oranges...

If this would be the most likely cause than that's it, but the difference is so big that I did not expect it. I'll see if I can level match it with REW soon.

For the sake of convenience I hoped to use the Wiim Pro Amp, but if the crossover is that important than I won't.

 

[l_lama]

Can you turn off the subwoofer and their filtering at all and see if the speakers itself are performing the same with both sets?

 

[Geertidow]

I'm not entirely sure but the first big thing is that I assume the two subs are managed independently with the miniDSP setup, whereas with the Wiim Pro Amp only you're just splitting a mono sub signal. Typically to properly integrate multiple subs you need to be able to manage each sub separately.

Correct, but for the comparison I've turned of all DSP on the subs except the described PEQ. Furthermore, the subs are beneath both mains, so the delay is the same

 

[melomane13]

If this would be the most likely cause than that's it, but the difference is so big that I did not expect it. I'll see if I can level match it with REW soon.

set the sames filters, for now you have +3db at 100hz and down...
LR is better for crossover filters, the reasons described in a simple form here:
https://en.wikipedia.org/wiki/Linkwitz–Riley_filter

 

[Geertidow]

set the sames filters, for now you have +3db at 100hz and down...
LR is better for crossover filters, the reasons described in a simple form here:
https://en.wikipedia.org/wiki/Linkwitz–Riley_filter
View attachment 500953

The BW crossover was designed by @OCA with brute force computing so for my case perfect.

 

[Mort]

The bass sounds a lot less controlled when listening

What exactly are you hearing? Is it possible to blind test?

 

[Geertidow]

What exactly are you hearing? Is it possible to blind test?

Blind is not possible I'm afraind, but the bass is louder but less controlled. But it might be that with a different crossover some peaks are not doing as good as with the old setup. I fear there is no other way then swapping and measuring to see what crossover is available on the Wiim that could pull it off.

 

[Geertidow]

Wait I did find this:
"

1. Amp Ultra preserves absolute signal polarity while Amp Pro inverts it on the loudspeaker output binding posts.
   • Interestingly the polarity is not inverted on the Amp Pro subwoofer output. I've opened a support ticket regarding all this and got the answer that loudspeaker output polarity will be corrected in one of the future Amp Pro firmware updates.
   • Until the firmware update is released, the polarity inversion issue of the Amp Pro can of course be worked-around by switching the loudspeaker cable polarity at the binding posts.

'"
On: https://forum.wiimhome.com/threads/...iim-amp-pro-and-wiim-amp-ultra-and-more.7830/

Maybe it hasnt been updates yet?

 

[Geertidow]

I did the works and swapped the system, then applied the sub and room correction programs from wiim themselves.
I am very impressed with it.
Now the bass sounds normal

Crossover at 90 Hz.

 

[ianjams21]

I did the works and swapped the system, then applied the sub and room correction programs from wiim themselves.
I am very impressed with it.
Now the bass sounds normal

Crossover at 90 Hz.

How's the difference now between the 2 systems?

1. Wiim Pro -> MiniDSP Flex balanced -> Audiophonics NC252MP.
2. Wiim Pro Amp with an RCA splitter to split the sub out to the subs.

I'm currently running KEF LS50 Meta + SVS SB3000 with Wiim Amp Ultra and wondering if it would be a nice upgrade to go separates with the following
Schiit Bifrost 2/64 - already - owned
Schiit Lokius - already owned
Jotunheim 2 - already owned
MiniDSP Flex - to purchase
Buckeye Purifi - to purchase

 

[Geertidow]

All in all I stayed with Wiim because I value ease of use and minimal cable clutter.

But, the bass with the miniDSP was better, but the difference was small. This is without blinding and level matching, who's to say. The bass with miniDSP was less loud but more clear.

 

[ianjams21]

All in all I stayed with Wiim because I value ease of use and minimal cable clutter.

But, the bass with the miniDSP was better, but the difference was small. This is without blinding and level matching, who's to say. The bass with miniDSP was less loud but more clear.

What exactly did you do to fine tune the settings and make them almost the same as the miniDSP setup??

 

[Geertidow]

What exactly did you do to fine tune the settings and make them almost the same as the miniDSP setup??

First, I did a PEQ on the subwoofers (50 Hz, -8dB, Q = 10) because I have a big room mode there. Crossover at 100 hz.
I used the UMIK-1 microphone with the calibration file and did the MMM method (advanced settings). Correction up to 200 Hz.
That's what I've been using. But the MiniDSP dit perform better, I really enjoy simplicity of the system since the whole household uses it.
I always used automatic switchoff of everything when not in use, but sill I enjoy the view of a single device.

 

[action123]

Wait I did find this:
"

1. Amp Ultra preserves absolute signal polarity while Amp Pro inverts it on the loudspeaker output binding posts.
   • Interestingly the polarity is not inverted on the Amp Pro subwoofer output. I've opened a support ticket regarding all this and got the answer that loudspeaker output polarity will be corrected in one of the future Amp Pro firmware updates.
   • Until the firmware update is released, the polarity inversion issue of the Amp Pro can of course be worked-around by switching the loudspeaker cable polarity at the binding posts.

'"
On: https://forum.wiimhome.com/threads/...iim-amp-pro-and-wiim-amp-ultra-and-more.7830/

Maybe it hasnt been updates yet?

This was supposedly fixed for Wiim Amp Pro back in software version 5.2.730558 according to the thread you posted (https://forum.wiimhome.com/threads/...-and-wiim-amp-ultra-and-more.7830/post-156989)

 

[Geertidow]

On other note, with simpler PEQ, would it make more sense to cross at 60 or 70 hz?

 

[Mort]

On other note, with simpler PEQ, would it make more sense to cross at 60 or 70 hz?

That depends more on your room and your system.