REW and the FBQ 2496 Transfer errors

[bob blancher]

Hi All,

I am in the middle of a room tuning process with my designer and am having a bit of a crisis. I understand that REW now states in its filter transfer dialogue box that communication is unreliable and to check the settings after the transfer.

My designer and I have been working for months up to this point and now are at an impasse. He believes my individual unit is to blame. I disagree because I have 3 of them and they all exhibit identical flawed behavior. I'm inclined to believe that the problem is far more systemic.

What I'm wondering is: can anyone shed any light as to the communication breakdown with these units and REW? What I'm experiencing mostly is inaccurate frequency center points being set on the FBQ during the transfer. The strange thing is that we have been proceeding this way and getting great results. I would load the filters and not correct them and the tuning process got to a point of +/- 1db up to 500hz..An astounding result to be sure. When I went back and corrected the frequencies, the results went haywire.

So, are display readings on the unit wrong? Do the filters actually load correctly and display inaccurate data? Or are they what they display says they are, and the data in REW isn't impacting the tuning of the box as anticipated?

I'm trying to reach out to Behringer as well, but don't have much hope there of course...

Thanks in advance for any help!

 

[Wayne A. Pflughaupt]

Please understand I don’t mean to snipe, but if REW says there’s a problem communicating with the 2496, and that’s what you’re experiencing, with three different equalizers no less - why are you still messing with it? Why not just manually enter the values REW recommends? Not sure how long that would take, but I’m confident it would be faster than “months.”

BTW, response +/- 1 dB? No one gets that without drastically over-equalizing. The goal with EQ is an audible improvement, not a pretty graph. Audible improvements are easily realized by concentrating on the worst peaks and troughs, not by chasing every little ripple in response. Plastering the system with a slew of filters, especially narrow ones with small gain values, typically only degrades performance, often audibly.

Here’s some reading that may help:
Minimal EQ and a Hard Knee House Curve
Spridle’s Experiment

Regards,
Wayne

 

[bob blancher]

You better hide under that chair pal!!!!

Thanks for the response though....I like that chair emoji......

I'm working with a professional for what its worth. This tuning process considers phase alignment along with decay, not just the SPL graph. It sounds as good as it looks. I definitely did not just wander into this as an amateur..Anyways, I definitely don't want to dive into that frey....

I have no issues with inputting the values manually, but something else seems to be going on here. Values that should be doing one thing appear to be doing another. We're talking about minor discrepancies, not major ones. This has lead to disagreements over what is actually happening. That is why I pose the question of whether the unit is displaying the wrong values or not. I'm looking to determine that in order to eliminate the suspicion. My designer appears to giving up on the process untiI prove that the box is not broken. Currently I am a bit off....sucks for me...LOL

 

[Wayne A. Pflughaupt]

LOL, thanks for being a good sport, Bob! I think this is the emoji you wanted: LOL

Can you give some details on exactly what is happening? Like, you enter a filter at 32 Hz and when you go back and check again it’s showing 44 Hz? Or bandwidths changing?

Regards,
Wayne

 

[EarlK]

I have no issues with inputting the values manually, but something else seems to be going on here.
Values that should be doing one thing appear to be doing another. We're talking about minor discrepancies, not major ones. This has lead to disagreements over what is actually happening. That is why I pose the question of whether the unit is displaying the wrong values or not. I'm looking to determine that in order to eliminate the suspicion. My designer appears to giving up on the process untiI prove that the box is not broken. Currently I am a bit off....sucks for me...LOL

You should be able to identify the apparent discrepancies ( between display & actual filter implementation ) by inserting one of your FBQ's ( loaded with a handful of REW generated filters ) into a soundcard loopback chain and then running REW ( through this FBQ ) to capture/save an EQed trace so that you can look/compare the effects of the ( FBQs ) loaded filters.

It's time to learn how to do the simple soundcard loopback ( if you don't already know how ).

 

[bob blancher]

Here's the list,

Mind you, they always load the same. The errors don't change. That would seem to be a communication issue between the objects. And yes I've tried all of the delay possibilities between 1000-2000ms

I'll give the soundcard loopback a look see....thanks

REW settings
Filter 1: ON PEQ Fc 20.00 Hz Gain -13.50 dB BW Oct 0.750
Filter 2: ON PEQ Fc 21.18 Hz Gain 5.00 dB BW Oct 0.500
Filter 3: ON PEQ Fc 24.32 Hz Gain -2.50 dB BW Oct 0.500
Filter 4: ON PEQ Fc 32.81 Hz Gain 3.50 dB BW Oct 0.750
Filter 5: ON PEQ Fc 39.00 Hz Gain 1.00 dB BW Oct 0.100
Filter 6: ON PEQ Fc 47.98 Hz Gain -3.00 dB BW Oct 0.750
Filter 7: ON PEQ Fc 53.83 Hz Gain -9.00 dB BW Oct 0.500
Filter 8: ON PEQ Fc 80.54 Hz Gain -1.50 dB BW Oct 0.750
Filter 9: ON PEQ Fc 103.8 Hz Gain -4.50 dB BW Oct 0.200
Filter 10: ON PEQ Fc 146.6 Hz Gain 3.50 dB BW Oct 0.125
Filter 11: ON PEQ Fc 157.0 Hz Gain -4.50 dB BW Oct 0.333
Filter 12: ON PEQ Fc 182.4 Hz Gain -2.00 dB BW Oct 0.143
Filter 13: ON PEQ Fc 237.7 Hz Gain -5.00 dB BW Oct 0.750
Filter 14: ON PEQ Fc 263.6 Hz Gain -4.50 dB BW Oct 0.100
Filter 15: ON PEQ Fc 289.1 Hz Gain 5.50 dB BW Oct 0.200
Filter 16: ON PEQ Fc 339.6 Hz Gain 1.50 dB BW Oct 0.067
Filter 17: ON PEQ Fc 403.7 Hz Gain -4.50 dB BW Oct 0.143
Filter 18: ON PEQ Fc 427.6 Hz Gain 4.00 dB BW Oct 0.143
Filter 19: ON PEQ Fc 474.3 Hz Gain -1.00 dB BW Oct 0.067
Filter 20: ON PEQ Fc 331.9 Hz Gain 4.00 dB BW Oct 0.067

FBQ settings
Filter 1: ON PEQ Fc 20.00 Hz Gain -13.00 dB BW Oct 0.750
Filter 2: ON PEQ Fc 20.46 Hz Gain 5.00 dB BW Oct 0.500
Filter 3: ON PEQ Fc 24.05 Hz Gain -2.50 dB BW Oct 0.500
Filter 4: ON PEQ Fc 32.06 Hz Gain 3.50 dB BW Oct 0.750
Filter 5: ON PEQ Fc 38.55 Hz Gain 1.00 dB BW Oct 0.050
Filter 6: ON PEQ Fc 46.88 Hz Gain -0.50 dB BW Oct 0.750
Filter 7: ON PEQ Fc 52.00 Hz Gain -9.00 dB BW Oct 0.500
Filter 8: ON PEQ Fc 79.62 Hz Gain -1.50 dB BW Oct 0.750
Filter 9: ON PEQ Fc 99.09 Hz Gain -4.50 dB BW Oct 0.200
Filter 10: ON PEQ Fc 141.6 Hz Gain 3.50 dB BW Oct 0.125
Filter 11: ON PEQ Fc 153.5 Hz Gain -4.50 dB BW Oct 0.333
Filter 12: ON PEQ Fc 182.4 Hz Gain -2.00 dB BW Oct 0.143
Filter 13: ON PEQ Fc 237.7 Hz Gain -5.00 dB BW Oct 0.750
Filter 14: ON PEQ Fc 263.6 Hz Gain -4.50 dB BW Oct 0.100
Filter 15: ON PEQ Fc 289.1 Hz Gain 5.50 dB BW Oct 0.200
Filter 16: ON PEQ Fc 339.6 Hz Gain 1.50 dB BW Oct 0.033
Filter 17: ON PEQ Fc 403.7 Hz Gain -4.50 dB BW Oct 0.143
Filter 18: ON PEQ Fc 427.6 Hz Gain 4.00 dB BW Oct 0.143
Filter 19: ON PEQ Fc 474.3 Hz Gain -2.50 dB BW Oct 0.050
Filter 20: ON PEQ Fc 331.9 Hz Gain 4.00 dB BW Oct 0.017