New DSP1124P BFD today!

**finalrinse** · **09-09-07, 08:32 PM**

Hello! I stopped by Guitar Center today and they had one new BFD in stock (build date 0701 with 1.4), so I bought it along with a M-Audio MIDIsport UNO. I have no idea if I can get it all working, but am reading all the threads, manuals and help files for the BFD and REW. I'll try not to bother all of you too much, but I have a feeling I may need some help, as it seems overwhelming at the moment.
Tom

**brucek** · **09-09-07, 09:39 PM**

Yeah, it seems a bit much at first, but if you read those REW Help files, you'll get onto it once you load the program and start playing around.....

brucek

**finalrinse** · **09-09-07, 11:34 PM**

Quote:

brucek wrote:

Yeah, it seems a bit much at first, but if you read those REW Help files, you'll get onto it once you load the program and start playing around.....

brucek

Thanks for the encouragement! I just calibrated my sound card and saved the cal file, an Audigy2 NX external USB. I think that turned out ok. I believe my B&K SPL meter and mic are very flat so I'm assuming a cal file is not necessary for them? I will continue tomorrow night. Not sure what step should be next, should I hook up the BFD right away? Or just take some measurements? I have both AVIA and Video Essentials, should I use them or just use the sweeps and tones with REW? I hope you don't mind these questions.
Thanks,
Tom

**Otto** · **09-10-07, 08:30 AM**

Hi Finalrinse, and welcome to the Shack. Sounds like things are going well so far.

I've never used a B&K SPL meter, but I know they make nice stuff. I'd still poke around for a cal file, or the meter's stated frequency response. It'd be best to know for sure, but you move forward either way.

I'd probably just start taking some measurements at this point. Get yourself familiar with the REW tool and see what it can do. Of course, it won't hurt to have the BFD connected, so you can do that if you're all ready to go. After taking a few measurements, you'll almost certainly want to make some adjustments, so it would be convenient to already have it in the circuit.

To make measurements and adjustments using REW, you will need to use the sweeps that are generated by REW. AVIA and VE discs won't be any help here. You can use those test discs later to set your levels -- REW doesn't have any Dolby/DTS stuff in it, so it can't assign signals to each individual channel in your system.

Good luck!

**Wayne A. Pflughaupt** · **09-10-07, 02:32 PM**

Quote:

I'll try not to bother all of you too much,

Oh, please do! Things have been pretty quiet around here lately, and we need something to do!

Regards,
Wayne

**finalrinse** · **09-10-07, 05:58 PM**

Quote:

Wayne A. Pflughaupt wrote:

Oh, please do! Things have been pretty quiet around here lately, and we need something to do!

Regards,
Wayne

Thanks! I appreciate it!
Tom

**finalrinse** · **09-10-07, 06:11 PM**

Quote:

Otto wrote:

Hi Finalrinse, and welcome to the Shack. Sounds like things are going well so far.

I've never used a B&K SPL meter, but I know they make nice stuff. I'd still poke around for a cal file, or the meter's stated frequency response. It'd be best to know for sure, but you move forward either way.

I'd probably just start taking some measurements at this point. Get yourself familiar with the REW tool and see what it can do. Of course, it won't hurt to have the BFD connected, so you can do that if you're all ready to go. After taking a few measurements, you'll almost certainly want to make some adjustments, so it would be convenient to already have it in the circuit.

To make measurements and adjustments using REW, you will need to use the sweeps that are generated by REW. AVIA and VE discs won't be any help here. You can use those test discs later to set your levels -- REW doesn't have any Dolby/DTS stuff in it, so it can't assign signals to each individual channel in your system.

Good luck!

Thanks Otto!
Yes, I think within a few hours I will try to take some measurements. I think I will hook up the BFD. It looks like the REW help file gives two scenarios. The first one show not using the A/V receiver and the second one does. I'm leaning towards the first one, I guess I'm not quite sure at this point how to completely turn off my other 7 speakers, short of disconnecting them. what do you think?
Tom

**brucek** · **09-10-07, 07:18 PM**

Quote:

The first one show not using the A/V receiver and the second one does. I'm leaning towards the first one, I guess I'm not quite sure at this point how to completely turn off my other 7 speakers, short of disconnecting them. what do you think?

You are correct in choosing to test through the AV receiver. This is because we want the bass management in place to give us a crossed over signal to the subwoofer through the BFD. We also want the receiver to allow for easy level setups. The BFD only route is used when you don't have the receiver available. Once the subwoofer is equalized without the mains, then the mains are turned on and the crossover area is worked on for a smooth transition.

You disconnect the other speakers by disconnecting the speaker wires at the receiver (while it's turned off of course). Then when you need them, hook them back up (with the receiver off, of course). You only need to disconnect the two mains because all testing is done in stereo only mode, so the other speakers will not be active and so we don't disconnect them.

brucek

**finalrinse** · **09-10-07, 08:09 PM**

Quote:

brucek wrote:

You are correct in choosing to test through the AV receiver. This is because we want the bass management in place to give us a crossed over signal to the subwoofer through the BFD. We also want the receiver to allow for easy level setups. The BFD only route is used when you don't have the receiver available. Once the subwoofer is equalized without the mains, then the mains are turned on and the crossover area is worked on for a smooth transition.

You disconnect the other speakers by disconnecting the speaker wires at the receiver (while it's turned off of course). Then when you need them, hook them back up (with the receiverr off , of course). You only need to disconnect the two mains because all testing is done in stereo only mode, so the other speakers will not be active and so we don't disconnect them.

brucek

Ok great!
Thanks!

**finalrinse** · **09-12-07, 06:19 AM**

I measured my system last night for the first time, and also had the BFD hooked up. My system sounds so much smoother now! I can now run my subs volume higher with a couple of the peaks gone. My subs are only good to about 30Hz though, at least that how it looks to me. I have (2) Energy 8" sub's Teed together. I'm in a fairly good size great room that is open to most of the house, not ideal. In the future I would like to replace them with one better sub, maybe $800 range. Anyway, getting back to the BFD; I forgot to save the filters as a file so I could pull them back up, I noticed the feature to retreave from the BFD is greyed out. I thought, well no problem, I'll just cycle through them on the BFD and write them down. I don't think they are exactly the same though, the frequencies look like they might be rounded out, is this true? Is there a way to read out the same what REW was reading? I'm very pleased so far and thank all of you!
Please advise if I should change my filters?

**brucek** · **09-12-07, 06:36 AM**

Looks like a good job.

Yeah, you can easily read the filters from the BFD and write them down and they will match exactly what REW suggested. Go to REW and click the EQ filters icon and enter a random filter and see how REW defines them. The frequency in the Frequency thumbwheel interprets what's on the BFD front panels two windows of Freq + Fine. REW also shows the Freq + Fine in Green for those numbers. So, you can recreate the exact match from the front panel.

Why are you using such a high target crossover in REW and not something like 80Hz? Hopefully this is a measure of your sub(s) only without the mains?

brucek

**finalrinse** · **09-12-07, 12:49 PM**

Quote:

brucek wrote:

Looks like a good job.

Yeah, you can easily read the filters from the BFD and write them down and they will match exactly what REW suggested. Go to REW and click the EQ filters icon and enter a random filter and see how REW defines them. The frequency in the Frequency thumbwheel interprets what's on the BFD front panels two windows of Freq + Fine. REW also shows the Freq + Fine in Green for those numbers. So, you can recreate the exact match from the front panel.

Why are you using such a high target crossover in REW and not something like 80Hz? Hopefully this is a measure of your sub(s) only without the mains?

brucek

Thanks for the reply brucek! I thought I was using 80Hz for crossover. Do you see something in my graphs that show I have a high target? Sorry, but I need all the help and advise I can get. I put my receiver in 2ch stereo mode and unplugged the front two speakers, and all my speakers are set to small and 80Hz crossover. Maybe I missed something or something is messed up. I did notice I had some peaks between 160 and 200Hz that the filters would not react with too well. Should I not worry about peaks above say 100Hz? I guess I don't quite understand some of these large peaks around 200Hz with a 80Hz crossover???
Thanks!
Tom

**brucek** · **09-13-07, 10:46 AM**

Quote:

Do you see something in my graphs that show I have a high target?

Ooops, I asssumed you were using the standard horizontal scale of 15Hz to 200Hz and now I see you chopped your graph off at 100Hz. I should have looked closer.

Quote:

Should I not worry about peaks above say 100Hz? I guess I don't quite understand some of these large peaks around 200Hz with a 80Hz crossover???

Again, since you chopped your graphs off at 100hz instead of 200Hz, I can't really comment on the upper frequencies. In general though, the higher you advance in frequency in relation to the crossover, the less effect the BFD filters will have in the overall response once the Mains are added. The Mains will overwhelm the mix between the sub and mains (at 150Hz for example), because the level of the mains will be much higher in level. See the graph below showing the perfect world of a sub and mains signal (this would be the voltage sent from the receiver before it got to the speakers)....

80crossover sub plus main.jpg

brucek

**finalrinse** · **09-13-07, 05:50 PM**

Quote:

brucek wrote:

Ooops, I asssumed you were using the standard horizontal scale of 15Hz to 200Hz and now I see you chopped your graph off at 100Hz. I should have looked closer.

Again, since you chopped your graphs off at 100hz instead of 200Hz, I can't really comment on the upper frequencies. In general though, the higher you advance in frequency in relation to the crossover, the less effect the BFD filters will have in the overall response once the Mains are added. The Mains will overwhelm the mix between the sub and mains (at 150Hz for example), because the level of the mains will be much higher in level. See the graph below showing the perfect world of a sub and mains signal (this would be the voltage sent from the receiver before it got to the speaker)....

Attachment 4342

brucek

Brucek - I think I'm beginning to understand now why the filters at the upper end don't do much, the 80Hz filter, the roll off, plus the peak is actually down about 20dB. Here's a snap shot of my original sweep out to 200Hz. I haven't run a sweep with mains yet.
Thanks,
Tom

**1984911Porsche** · **09-30-07, 12:28 PM**

Quote:

finalrinse wrote:

Hello! I stopped by Guitar Center today and they had one new BFD in stock (build date 0701 with 1.4), so I bought it along with a M-Audio MIDIsport UNO. I have no idea if I can get it all working, but am reading all the threads, manuals and help files for the BFD and REW. I'll try not to bother all of you too much, but I have a feeling I may need some help, as it seems overwhelming at the moment.
Tom

I was going to look for a 1124 today, is there a build date that we want to stay away from?

Thanks

**brucek** · **09-30-07, 01:49 PM**

It's the firware revision that you're looking for. You need a vers 1.4 to have the software that works with the midi of REW. If you have vers 1.3 and you want to use midi to enter filters rather than the front panel entry method, you would need to change the eprom inside.

brucek

**1984911Porsche** · **09-30-07, 02:03 PM**

Thanks Bruce,

I forgot to come back after reading more. It looks like the 1124P is no longer made, so hope I can find one.

Michael

**Bent** · **10-01-07, 05:01 PM**

Sonnie - (and Bruce, etc), I haven't set up my 1124P yet, but I have installed it and am running with no eq aplied for now.

Mine shows Version 1.0, will this present any REW interconnectivity problems?

**brucek** · **10-01-07, 05:54 PM**

Quote:

Mine shows Version 1.0, will this present any REW interconnectivity problems?

No, vers 1.0 is fine........

brucek

**Bigdaddy999** · **10-04-07, 09:16 PM**

Hi all. Just got my BFD and am waiting for my second sub to arrive. I have a question about the use of REW. Once I have an REW measurement, do I use the EQ window (as shown above) to flatten the response curve, and then enter those values into the BFD filter by filter?? In the graph above, the EQ window shows a number of selected settings - those are what you pound into the BFD?

Sorry if this is a dumb question, but it was pretty cool to see that REW "knew" the 1124.

Thanks

**brucek** · **10-04-07, 09:45 PM**

Quote:

do I use the EQ window (as shown above) to flatten the response curve, and then enter those values into the BFD filter by filter??

Yes, you enter all the suggested filters. You can also tweak them a bit or add your own to REW if you like. Be sure to run the optimizer.

Quote:

In the graph above, the EQ window shows a number of selected settings - those are what you pound into the BFD?

Well, you enter the frequency, gain and bandwidth of each filter. Don't forget to optimize the filters after you assign them in REW.

Quote:

Sorry if this is a dumb question, but it was pretty cool to see that REW "knew" the 1124.

You select the type of equalizer you are using in the equalizer pull-down. 1124 is the default.

brucek

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