More first REW graphs - thoughts?

**avnetguy** · **07-20-06, 12:27 AM**

Started off with room position testing tonight, here are the perferred choices for the Velo DPS-12.

Location1

Location2

Location3

AVR crossover is set at 90hz with the sub crossover disabled.
mic and sound card calibrated, sub output only.

Thoughts on best position and use of a BFD?

Thanks,
Steve

**Sonnie** · **07-20-06, 01:44 AM**

Hey Steve and welcome to the Shack!

I definitely like Location 3 the best. It gives you more low end extension. It would be easy to tame that with the BFD too.

You should shoot for getting the full benefit of your sub anyway, which the DPS-12 is rated down to 25hz.

**avnetguy** · **07-20-06, 11:52 AM**

Thanks for the welcome Sonnie!

Quite the good forum here though I'm sure it'll get me in trouble soon as its got me thinking of doing either a DIY cylinder or IB sub project soon.

So after those tests I hooked up the BFD with the sub at location 3. Now I've got a problem, the BFD doesn't seem to be working.

As a test, I set one filter up with the following data,

Filter Mode: PA
Engine: Used couple mode (Both L and R)
Freq: 50Hz
Fine: 0
Bandwidth: 7
Gain: -24db

Only the first two red filter LEDs stay on solid, the rest are off as I turned all the other filters to off.

The signal passes through to the sub correctly as I get the same result in REW. The BFD vu meters show only the lowest green LED (input set at -10dbv BTW) on when I run the sweep, not sure if the level should register higher? I tried all modes of the IN/OUT button to see if there was a difference but nothing changed.

Did I miss something or could I have a bad BFD?

Thanks,
Steve

**brucek** · **07-20-06, 12:00 PM**

Quote:

The BFD vu meters show only the lowest green LED (input set at -10dbv BTW) on when I run the sweep

The BFD input level is a separate setup. Don't worry about it when using REW.

The IN/OUT LED should be on solid for the filters to be engaged.
If you have a filter at 50Hz entered in the BFD for a test, then use REW as a simple signal generator and output a tone at 50Hz. Now move the gain of the filter up and down and observe (or not) the level of the SPL meter (either the real one or the REW meter)...

brucek

**avnetguy** · **07-20-06, 03:19 PM**

BFD works fine once the operator error is fixed.

Location 3 + BFD w/ 3 filters

Steve

**brucek** · **07-20-06, 03:40 PM**

Excellent..................smooth as silk.............

**JohnM** · **07-20-06, 04:32 PM**

As an aside, if you go to the Measured Responses graph page (drop-down top right of REW) you can look at all the measurements at once and more easily compare them. Might want to try filters at 50Hz and 68Hz and perhaps also at 34Hz (all approx from eyeballing the graph).

**avnetguy** · **07-20-06, 08:58 PM**

Quote:

JohnM wrote:

As an aside, if you go to the Measured Responses graph page (drop-down top right of REW) you can look at all the measurements at once

Ahhh, I like that view, very handy!

I'll still need to spend some time tailoring the curve with REW and by listening. After that I'll fill in a few of my favorites into the presets on the BFD. Its amazing how good both of these tools (REW/BFD) are and gets one wondering why they, we'll at least a PEQ, are not found in AVR receivers nowadays.

Steve

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