# Just got my DSP1124P, read the BFD guide and still confused>>



## deepstang (Nov 17, 2009)

Thanks to the Shack, I already have REW up and running just well. Thanks to REW, I realized I could used a BFD. I just got my DSP1124P in and read pages 10-12 as recommended. I also read every BFD set-up guide I could find on the Shack. 

So, as of now I have a dual subwoofer set-up (that are NOT equi-distant/symmetrical) with a single RCA/LFE cable running to the first sub and than Y-split to the other. I need to go to Fry's/Radio Shack and get that converter for that funny plug in the back.

Because I have the laptop set-up with REW, I am definitely on board with having REW do all the hard work for me. My biggest point of confusion is on what to do once I have the BFD connected to the subs (as described above), and what the set-up process is to get REW to talk to the BFD. 

I came across this post in the BFD FAQ thread and totally want to emulate it:

http://www.hometheatershack.com/for...-bfd-guide-quick-links-faq-tips.html#post1063

I guess I need to figure out how to connect my laptop to the MIDI connector on my BFD. Once that is done, I have no idea how REW will automatically help apply the appropriate filters and communicate that to the BFD. I am so excited, and look forward to your help. THANKS!!


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## deepstang (Nov 17, 2009)

I was able to get a short RCA cable and 2 1/4 to RCA connectors. I also found the MIDI to USB cable.

I am not sure how REW will interface with the BFD, but I guess there is only one way to find out. Again, i could not find any links or info on how to incorporate REW with the BFD. 

Maybe I need to look in the REW threads and not the BFDs. Light Bulb on!!

**EDIT: update**

This is the link I was looking for:

http://www.hometheatershack.com/roomeq/wizardhelp/help_en-GB/html/bfdcomms.html#top


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## deepstang (Nov 17, 2009)

Ok, I know this seems to be a conversation with myself; however, I could use a little help.

Isn't it possible for REW to communicate with the BFD and apply the appropriate calibration??


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## JohnM (Apr 11, 2006)

I'm not sure what you mean by "apply the appropriate calibration", but REW can send filter settings to the BFD over the Midi connection to save putting them in manually. The steps are:
- make your measurement(s)
- apply and adjust some filters within REW to get the response you are aiming for (or ask REW to find peaks in the measurement, apply filters to the peaks and then optimise the gain and Q settings for the filters)
- send the filters to the BFD using the command in the Equaliser menu, or enter them manually
- re-measure to make sure the result is what you expected/wanted.

The process is described in detail in Filter Adjustment.


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## deepstang (Nov 17, 2009)

JohnM said:


> - apply and adjust some filters within REW to get the response you are aiming for (or ask REW to find peaks in the measurement, apply filters to the peaks and then optimize the gain and Q settings for the filters)
> Filter Adjustment.


I guess applying the filters is where my confusion is. I found that link helpful; however, I did not know if I have the right settings in the "Filter Tasks" drop down. I would rather go the route of REW finding the peaks and automatically apply the settings. I will just download that to the BFD. That link was great, but unless I missed a part, it did not tell me the exact parameters that I should set and what to finally click for REW to automatically detect the peaks and apply the appropriate filters. Thanks!


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## JohnM (Apr 11, 2006)

It is basically as set out in that section of the help file. You click:

"Find Peaks" then
"Assign filters" then
"Optimise Peak Gain & Q".

If you post some plots of the results we can comment on whether it looks like it went OK (click on the floppy disk icon in the bootm right corner of the graph to save it as a jpeg).


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## deepstang (Nov 17, 2009)

<deleted> Answer found.


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## deepstang (Nov 17, 2009)

Sorry for the silly questions, as I stumbled across the appropriate links and found the answers to almost all my questions. I do want to ask about the TARGET SETTINGS menu. I know it is said to keep the "Cutoff" at 80hz as that is the most common. With my Onkyo, I have my full range speakers crossed at 80Hz....and have *my sub LFE at 120Hz*. I know the info from 80hz to 120hz going to the sub will be very minimal; however, I wanted to know if I should still leave the REW "Cutoff" at 80Hz...or 120Hz. Thanks.


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## glaufman (Nov 25, 2007)

When you say "my sub LFE at 120Hz" do you mean the control on the sub, or in the AVR?
If on the sub, do you have a way to bypass that entirely? If not, set it as high as it will go. If that's 120, so be it. If you mean in the Onkyo, set it to 80 like the mains. 
Either way, leave the REW target at 80Hz.


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## deepstang (Nov 17, 2009)

glaufman said:


> When you say "my sub LFE at 120Hz" do you mean the control on the sub, or in the AVR?
> If on the sub, do you have a way to bypass that entirely? If not, set it as high as it will go. If that's 120, so be it. If you mean in the Onkyo, set it to 80 like the mains.
> Either way, leave the REW target at 80Hz.


The subs are on bypass and the LFE for the subs on the receiver is set at 120hz....and 80hz on the mains. So regardless i will leave the REW target at 80Hz. Gotcha. thanks!!


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## glaufman (Nov 25, 2007)

Do you mean the "LPF" for the subs on the receiver? If you are going to leave it at 120, then you might want to change the setpoint in REW to 120... it depends on how you're running your scan. If you've connected the soundcard output to the main channel in on the AVR, leave REW at 80. If you've connected the soundcard output to the SUB only, or the SUB input on the AVR, then reset REW to 120. 

But I recommend setting the LPF for the sub at 80, the same as the mains.


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## deepstang (Nov 17, 2009)

Thanks Greg. Over at AVSforums I have read several times that it may be a good idea to leave the LPF to 120hz and mains at 80hz. Supposedly subs are better than mains in producing 80-120hz??

Maybe I will take ur advice and do that. When I run REW, I have the right RCA out on the sound-card going into the right of the receiver input...and I disconnect the RIGHT main speaker. I can try sweeps with the main speaker connected and also play with the different crossover settings to see what the best final result will be. I guess if the mains are crossed at Hz, anything above that should be very minimal going to the sub. Thanks!


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## glaufman (Nov 25, 2007)

Respectfully, I think you may have misunderstood. Some subs may be better than some mains at reproducing 80-120Hz, but if that's the case in your situation then the mains should be set to 120Hz as well.
80Hz is a good rule of thumb for most systems in the absence of any data to the contrary, as above this frequency sound becomes increasingly localizable, and we usually don't want to be able to localize our subs. 
That being said, and now that you mention it, the LFE channel is allowed to have sound coded at up to 120Hz, meaning that if a true crossover is set at 80Hz, the receiver SHOULD direct some portion of the LFE's 80-120Hz content to the main speakers at the same time as it's directing a portion of the main channel's <80Hz content to the sub... If a receiver does not do this, and allows separate setting of HPF for the mains and LPF for the sub, then I suppose it could be better to leave the LPF for the sub at 120 (or even higher)... but if it was my system, I'd want to run tests to determine exactly how this works to make sure that the AVR isn't taking any 80-120Hz content and "doubling" it to both mains and sub channels equally, such as would be done with <80hz content in AVRs with a "double bass" setting...
Sorry for the verbosity, but I think you get where I'm going with that...


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## deepstang (Nov 17, 2009)

I finally got all me wires and am on the first step.....getting the volume/level on the AVR to the right level so that the BFD has the appropriate input. I initially had my LPF/sub level on the AVR at -8, but in order to get JUST the green lights lit 60%, I had to turn the LPF/sub up to +4. I kind of feel bad taxing my AVR more (increase in 10 pints) just to get the BFD to light up. I still don't even seen yellow or red, but don't know if I want to go above +4 on my AVR level. AM I doing something wrong, or should I bump the LPF/SUB even higher till I see a little red on the LEDS when I play bass heavy items at max listening volumes??


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## deepstang (Nov 17, 2009)

deepstang said:


> I finally got all me wires and am on the first step.....getting the volume/level on the AVR to the right level so that the BFD has the appropriate input. I initially had my LPF/sub level on the AVR at -8, but in order to get JUST the green lights lit 60%, I had to turn the LPF/sub up to +4. I kind of feel bad taxing my AVR more (increase in 10 pints) just to get the BFD to light up. I still don't even seen yellow or red, but don't know if I want to go above +4 on my AVR level. AM I doing something wrong, or should I bump the LPF/SUB even higher till I see a little red on the LEDS when I play bass heavy items at max listening volumes??


Can someone help me answer the above please. Thank u!


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## Wayne A. Pflughaupt (Apr 13, 2006)

> I kind of feel bad taxing my AVR more (increase in 10 pints) just to get the BFD to light up. I still don't even seen yellow or red, but don't know if I want to go above +4 on my AVR level.


It’s only a line-level signal. It does not “tax” the AVR to increase it. Make sure you have the switch on the back of the BFD switched to the -10 dBV setting.



> AM I doing something wrong, or should I bump the LPF/SUB even higher till I see a little red on the LEDS when I play bass heavy items at max listening volumes??


There’s no need to turn the signal up so high that the red LEDs come on. In fact, it’s best to leave some head room. As long as you’re hitting solidly in the green, you’re fine.

Regards,
Wayne


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## deepstang (Nov 17, 2009)

Thanks Wayne. I double checked and have the button properly pressed. BTW, if I am only using the LEFT side of the BFD, is it normal for the RIGHT side RED LED to contine to constantly blink like a bomb??


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## Wayne A. Pflughaupt (Apr 13, 2006)

Are you talking about the input level meter, or some other red LED?

Regards,
Wayne


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## deepstang (Nov 17, 2009)

It is not the green LED lights that are small and vertical all the way to the left....but the long and red led lights that go in a horizontal fashion. BTW, Wayne, I would be very grateful if you can also please help me answer this question about getting the data so that I can apply a House Curve:

http://www.hometheatershack.com/for...-apply-house-curve-using-rew-my-dsp1124p.html

Thanks!!


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## Wayne A. Pflughaupt (Apr 13, 2006)

Ah, okay. Those lights tell you which filters are being used. Just set the right one to “OF”, or “PA” with the gain set to zero.

Regards,
Wayne


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## deepstang (Nov 17, 2009)

Thanks Wayne.

Here is the graph with NO peq used:









Here is the graph AFTER the BFD was used:









I am still trying to figure out how to get a House Curve applied. From reading the instruction page I was wondering if I made a text file consisting of:

"*20 6.0, 80 0.0*" 

Would that do the trick?


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## deepstang (Nov 17, 2009)

Wayne A. Pflughaupt said:


> Ah, okay. Those lights tell you which filters are being used. Just set the right one to “OF”, or “PA” with the gain set to zero.
> 
> Regards,
> Wayne



I guess I have to go through each of the 12 possible PEQ options and turn them to 'of' for the RIGHT channel....for each save calibration....right?


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## Wayne A. Pflughaupt (Apr 13, 2006)

deepstang said:


> I am still trying to figure out how to get a House Curve applied. From reading the instruction page I was wondering if I made a text file consisting of: "*20 6.0, 80 0.0*" Would that do the trick?


That would do it. You want the high Hz number to be your crossover frequency, and the low Hz value to be where you want the curve to level off. You might experiment with other values between 20-30 Hz. As noted on your other thread, the interpolation function flattens the Target if you want a hard knee curve.

Regards,
Wayne


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## Wayne A. Pflughaupt (Apr 13, 2006)

deepstang said:


> I guess I have to go through each of the 12 possible PEQ options and turn them to 'of' for the RIGHT channel....for each save calibration....right?


Only needed for the memory settings you actually intend to use.

Regards,
Wayne A. Pflughaupt


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## deepstang (Nov 17, 2009)

It seems to turn off those blinking lights for the un-used RIGHT channel.....for EACH saved program I have to go EACH individual LED light (for the right channel) via "FILTER SELECT", and than use the "FILTER MODE" to change that to OFF. I am guessing that I can do this via REW by adjusting the whole set to off in the "EQ" section and apply that to the right side.

It is amazing how this learning curve grows the more time i spend with the BFD and REW. OK, so let me refer to this box:










I initially thought that if the "PEAKS FOUND" table shows 6 boxes that 6 PEQ filters should be applied. I tried to force that and noticed that it seems almost arbitrary how the frequencies are rounded.....and when I forced them in by changing the "TYPE" from NONE to PA (in the EQ filters chart above) that the extra frequencies from the Peaks Table are redundant frequencies that have a different gain. For example there may be 2 frequencies listed (in green on the table above) of "100", but with different gains (one positive and one negative). SO, is it best to leave the EQ filters chart alone and not try to get the number of PEAKS found coincide with the number of PEQs applied??


I also now noticed the "STORE" button keeps blinking in red every time I import a set of filters. Do I need to press the STORE button on the DSP1124P every time I import a set of filters?


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## deepstang (Nov 17, 2009)

New question:

If i am seeing gain amounts of say +10 for a frequency, and I notice that the boost does nothing to boost the REW curve at that frequency....should I remove that +10 gain?? Actually, the +10 gain seems to tame the curve in that frequency. Advice please.


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## Wayne A. Pflughaupt (Apr 13, 2006)

deepstang said:


> It is amazing how this learning curve grows the more time i spend with the BFD and REW. OK, so let me refer to this box:
> 
> 
> 
> ...


Not sure what you mean by “force that” and “frequencies being rounded.” :huh:

The frequencies listed in green are EQ settings for the equalizer. With most equalizers, you would just dial in the numeric frequency. The BFD is kind of weird, in that you select a “base” frequency at 1/3-octave intervals (125, 100, 80 Hz etc.) and then dial up or down from there in increments (+1 to +10 or -1 to -9). The figure in the “Frequency” box (in the REW EQ Panel) shows the exact frequency that 80 +4, for instance, actually is. Yeah, I know it’s confusing; the BFD’s controls aren’t terribly intuitive, even for people familiar with using parametric EQs, so don’t feel bad. )

By the way, I hope that’s not one of your EQ settings in that picture, there are some bad problems with it. Typically there’s no reason to apply any filters as high as 125 Hz, as most subs run at 80-100 Hz and lower. Before running the “Find Peaks” function, limit it to the sub’s range to the crossover frequency (“Filter Tasks” icon).

And the cuts of the first two filters are really severe. You should re-adjust the Target Curve (“Set Target Level” function under “Target Settings” icon) before running the “Find Peaks” function.



> I also now noticed the "STORE" button keeps blinking in red every time I import a set of filters. Do I need to press the STORE button on the DSP1124P every time I import a set of filters?


Anytime filter changes have been made, the “Store” light blinks. Store them if you want to keep the changes.

Regards,
Wayne


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## Wayne A. Pflughaupt (Apr 13, 2006)

deepstang said:


> New question:
> 
> If i am seeing gain amounts of say +10 for a frequency, and I notice that the boost does nothing to boost the REW curve at that frequency....should I remove that +10 gain?? Actually, the +10 gain seems to tame the curve in that frequency. Advice please.


Hard to say without seeing a graph and exactly where you are boosting, but sometimes a null won't respond to a boost. Also, if you're boosting beyond the sub's range, you won't see any "action" either. In either case, eliminate the filter.

Regards,
Wayne


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