Tweaking my "Hafler circuit" pseudo 5.1 setup

[olds1959special]

This is my "Hafler circuit" pseudo 5.1 setup that is possible with the MiniDSP 2x4 HD. I just finished trying to get all the levels right by ear as a starting point before I measure with my measurement mic. The front speakers are Dynaudio BM5A Mk2 with the 80Hz HPF engaged, to go with the Klipsch R-SW121 subs underneath each speaker, that have the LPF set at 80Hz to match. The rear speakers are KRK S10 V2 subwoofers with Yamaha MSP5 V2 speakers connected through the crossover at 80 Hz. The center speaker is a Yamaha NS-C225 powered by an Aiyima A70 Mono amp along with a center ELAC SUB1010 subwoofer set at 110 Hz LPF to match the output of the speaker (possible with the addition of a stereo-to-mono converter box.) The big desk does create a slight issue I think because of resonance though, but I keep the center speaker turned down slightly.

I sense the sound is pretty bass heavy in the room, but this is more or less the way I like it from trying to tweak things on a basic level. I will measure with my ECM8000 and post my results soon! I am wondering if any additional EQ is needed.

I like this setup because any stereo sound will provide a surround sound experience, just like a surround sound receiver but without the bulk. I'm posting pics and settings for those who are interested!

 

[olds1959special]

I found a peak at 122Hz which I brought down! (This is before EQ):

 

[Sokel]

Your response is strange up high, are you sure your mic's calibration file is properly loaded and is the right one?

 

[olds1959special]

Your response is strange up high, are you sure your mic's calibration file is properly loaded and is the right one?

Hmm, I read the ECM8000 is more accurate without the cal file? I loaded the cal file I found on the internet and re-measured (with EQ to lower the 122 Hz peak) and here are the results.

 

[sergeauckland]

The ECM8000 needs an individual calibration file, as the production spread still results in considerable errors if using a 'generic' calibration file. The ECM8000 is good enough uncalibrated for non-legally binding SPL measurements and for setting up subwoofer levels, and perhaps for in-room measurements as the errors are quiet high. It's definitely not good enough for making pseudo anechoic on-axis loudspeaker measurements without an individual calibration file, at which point it's very good, even disregarding the price.

S.

 

[olds1959special]

My latest measurement with cal file (122 Hz reduced as shown below.) The high end does look less peaky with the generic cal file.

 

[olds1959special]

The ECM8000 needs an individual calibration file, as the production spread still results in considerable errors if using a 'generic' calibration file. The ECM8000 is good enough uncalibrated for non-legally binding SPL measurements and for setting up subwoofer levels, and perhaps for in-room measurements as the errors are quiet high. It's definitely not good enough for making pseudo anechoic on-axis loudspeaker measurements without an individual calibration file, at which point it's very good, even disregarding the price.

S.

Do I need a UMIK?

 

[sergeauckland]

Do I need a UMIK?

That seems to be a popular choice, given that it integrates directly with REW and comes with a calibration file. If I hadn't already calibrated my ECM8000, I probably would have bought a Umik.

Buying a Umik is probably cheaper than sending your ECM away for calibration, unless you can borrow an already calibrated microphone and calibrate your own. I did it, and it's a real Faff.

S.

 

[olds1959special]

That seems to be a popular choice, given that it integrates directly with REW and comes with a calibration file. If I hadn't already calibrated my ECM8000, I probably would have bought a Umik.

Buying a Umik is probably cheaper than sending your ECM away for calibration, unless you can borrow an already calibrated microphone and calibrate your own. I did it, and it's a real Faff.

S.

Do I need Umik 1 or 2?

 

[sergeauckland]

Do I need Umik 1 or 2?

I'm not familiar with the differences so can't help, but others may be able to advise.

S

 

[olds1959special]

I'm not familiar with the differences so can't help, but others may be able to advise.

S

I’d rather have my ECM8000 mic calibrated.

 

[Joe Smith]

This all seems to me like too much work...

 

[DVDdoug]

The published specs for the ECM8000 look excellent to me! (If they are honest.*) It should be good enough for room measurement/adjustment. You'll get bigger variations with slightly different mic placement.

As far I can find, Behringer doesn't offer individual calibration files, just "general" one for everybody. But there are independent labs that can calibrate a mic. (I think it costs about the same as buying a calibrated mic.)



* Eek!!! Just Googling-around, I found this:

Effective immediately, Cross·Spectrum has ceased selling calibrated Behringer ECM8000 microphones. The quality of ECM8000 microphones has deteriorated to the point that we can no longer justify the effort in dealing with non-functioning units or mics with extremely abnormal frequency responses.

 

[olds1959special]

The published specs for the ECM8000 look excellent to me! (If they are honest.*) It should be good enough for room measurement/adjustment. You'll get bigger variations with slightly different mic placement.

As far I can find, Behringer doesn't offer individual calibration files, just "general" one for everybody. But there are independent labs that can calibrate a mic. (I think it costs about the same as buying a calibrated mic.)



* Eek!!! Just Googling-around, I found this:

I ordered a Beyerdynamic MM1.

 

[skankhobag]

I was running a digitally derived Hafler circuit for over a decade until I replaced it with a pre/pro setup.

You should experiment with adding delay greater than 40ms so that you can get the rear audio out of Haas Effect range. 50 to 60ms works well.

I hope those rear subs aren’t being used for the Hafler circuit. Most of the low end in music is usually engineered to be in the middle so it gets cancelled out by the Hafler circuit.

I found it sounded great if I took the stereo difference signal (L-R, R-L) and ran that through both a low pass filter (-6dB/oct. @5kHz) and a stereo reverb (a not too live sounding small hall or chamber) really added a lot of dimension to the surrounds,

The low pass filter is really important because a lot of percussion tends to be panned to the sides and the derived surround signal will be too bright and sound unnatural. Live environments don’t have lots of treble in their ambience. That’s most especially the case when you consider the sound coming from behind you.

One thing to try as well and it’s free & easy: turn your surround speakers around and face them into the corners. This will make your surround sound much more diffuse and roll off the treble. Another thing to try while they’re facing the corners is put them on their sides and aim them up toward the rear ceiling corners. That will make your surrounds sound huge.

Those are my suggestions.

 

[olds1959special]

Measurements with the Beyerdynamic MM1 after EQ, facing towards the speakers and also upwards (since its a diffuse field mic.)

with the pink noise having one channel inverted, to activate the rear speakers also, it measures like this with the mic pointing up:

 

[olds1959special]

Due to gear ADD I moved everything around again. I have too many speakers and subwoofers. I took into consideration the previous post which mentioned the fruitlessness of using the subwoofers for the rear speakers, since most of the bass is mixed to be mono and therefore canceled out. I also really wanted to try using the crossovers built into my KRK subs so I moved them to the front, on top of my other subs. Although I'm using a MiniDSP I don't have enough channels with the 2x4 HD to LPF and HPF the subs. So I just used the crossover at 90 Hz and set the 12" subs to 80Hz LPF. I run unbalanced from the MiniDSP into the unbalanced inputs of the sub and then use balanced outputs to connect to the studio monitors. I also decided to flip the phase on the lower subs. I haven't measured yet but going by ear it's surprisingly not bad this way. There is a lot of impact in the bass, and using the crossover helps clean up the sound going to the satellites. I'm sure I could (and probably have to) EQ this to be better too. I'm going to measure with my Beyerdynamic MM-1 and 0 degree cal file.

EDIT: posted measurements after EQ. These measurements look better than the older ones I posted from my previous setup.

 

[Joe Smith]

I can’t help but feel that you’ve got too much firepower for the size of room you are working with. Perhaps try a less is more approach?

 

[olds1959special]

I can’t help but feel that you’ve got too much firepower for the size of room you are working with. Perhaps try a less is more approach?

For starters, I could easily get rid of the center subwoofer, but I guess I like the effect of feeling the bass from the center to go with the center speaker. Next I could get rid of one pair of subwoofers to avoid more overlap of sound in the bass range. It is a fairly small room and the 10" subs have the crossover so it would make sense to use those. They have a front firing bass port too. But for now, I am subjectively enjoying this with the EQ! What I'm doing has to do with using what I have laying around so I don't feel guilty about not using it (or I have to sell it) but I'm open to any gear reduction ideas that would lead to drastically better sound. I guess a 10" sub plays certain frequencies better than others, with the 12" optimized for lower ones, so combining them can't be totally bad, and flipping the phase on the bottom pair seemed to help, and not really a problem if you think about it since you have the rear channels facing from the back that generally don't have a lot of bass. I read about an approach using an LPF and HPF and each sub to make them only play certain frequency bands that they are optimized for, but my DSP doesn't have enough channels. The other nice thing about this setup is how the two subs act as speaker stands, allowing the speakers to be aligned with the subs. Those are my thoughts right now.

 

[olds1959special]

I deconstructed this setup and am not doing the Hafler thing anymore in my bedroom. It was a fun experiment. No more center speaker, center sub, and rears.