BFD filters nothing like predicted response.

[StephenP]

I finally got all the cables to hook up my 1100, and set the levels with U-571 (came from -4 to +7 btw). I think I understand how to set the filters manually with the numbers from REW, but I am unclear about how to choose which of the 10 presets I am setting and then loading it. I tried to use preset 1, set all the filters to PA, set all the proper numbers in and pressed save twice after each filter set. I can now scroll through the filters and see the numbers are still in there. The problem is now the curve has different peaks than before, and a huge dip (all the way off the chart) that doesn't match any filter frequencies. I havent moved the spl meter or changed anything. Whats going on? Why are the results nothing like the predicted REW line? Sorry I didn't bring my laptop to post the graphs. Also, when I close the filter window, REW seems to erase all the filters and I have to re-load them from the save file, is this normal? I am hoping the midi cable makes all this simpler when it comes...

[Otto]

Hi there,

I've never used the 1100, but I think it's pretty similar to the 1124. You can select the program you're using by turning the scroll wheel. It should be OK to use any you choose. I happen to use 5.

I'm not sure why you're getting a weird response... See if there's a dot in front of the frequency you set. If so, it will set your filter to be in the kHz range rather than Hz. That might be it, especially if your peaks/dips have moved higher than you'd expect.

When you say "close the filter window and REW erases the filters," I'm not sure. For each measurement in the left hand side, REW maintains filters in the filter window. You shouldn't have to reload. However, if you did a new measurement, the filters will not follow forward. Flip through your various measurements in REW. If you've calculated a filter for that measurement, then it will show up in the "Filters" window.

Using the MIDI connection does make things easier for me. I never have to think about scrolling and setting filter values, especially if I want to do a bunch of quick measurements and tweaks to filters. Of course, once you get the hang of it, it's not really that hard to set the filters by hand, but the MIDI connection does make it a little easier.

Good luck!

[terry j]

make sure you have the correct equalizer chosen in the eq tab??

[StephenP]

I redid the BFD setup using filter 5 and it worked perfectly this time, not sure why it didn't before. Now I have a couple more problems. I am unable to get the midi conrol part working. My midi cable is installed properly and is detected by REW, it lets me send the filters out, but the BFD doesn't seem to do anything. I did set all the midi options like REW says in my 1100. Is there suppossed to be some kind of acknowledgement after you send? What mode is the BFD suppossed to be in to do this? Do I need both the in and out cables connected to the in and out of the bfd? Manual mode is just about easier than figuring all this out.
The second problem is another hum. I fixed the big one by making a new cable from the receiver to the BFD using a stereo 1/4" plug. Now it seems there is a smaller ground loop between the BFD and the sub amp. Would another custom cable fix this problem also? I guess it would be worth the $9 at radio shack to buy the new plugs, but overall I think the BFD project is growing beyond what it is worth in cost and added system complexity.