# BFD Questions! House Curve Questions!



## Guest (Sep 1, 2006)

Howdy!

I have been reading these threads like mad and have found a ton of great information. I have a pretty good understanding of how this all works, but I do have some questions- hope you can help!

1. Determining House Curve: I understand how you find the low end by listening at 32 and 80 hz and then adjusting until they sound the same volume, but what about the high end? Same process?

2. Once you have calibrated for your House Curve, how do you match the sub to the fronts so the house curve is consistent into the highs? Could you adjust the volume on the sub and verify it all adds up by taking readings? Or do you have to adjust the level of the sub at the receiver?

I hope these make sense!

Ryan


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## brucek (Apr 11, 2006)

> Once you have calibrated for your House Curve, how do you match the sub to the fronts so the house curve is consistent into the highs?


Most of us around here use Room EQ Wizard software, and after we have equalized the sub alone, then add the mains and adjust the subwoofer amplifier to match levels at the crossover. If you have a BFD you can't really adjust the processor subwoofer trim at that point because it will upset the level feeding the BFD which was previously setup.

Without REW, you will simply adjust your subwoofer amp after equalization by ear. Whatever sounds good to you. There is no right or wrong level - just guidelines to match them so they blend together at the same level at the crossover.



> but what about the high end? Same process?


This would imply an equalizer being used on the mains? Not generally done since it adds noise and little is gained. Usually higher frequencies respond to room treatment..


brucek


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## Guest (Sep 1, 2006)

Thanks for the response, I appreciate it!

I am planning on using Room EQ and the BFD for the sub. I have a Yamaha 5790 with the YPAO feature which will adjust for the mains/surrounds. YPAO has different settings which may be interesting. You can allow it to self-calibrate as a Parametric EQ or you can adjust each channel via 7-Band Graphic EQ. Would you recommend not using the YPAO at all?

I will take measurements of the room WITHOUT treatment and see what happens. I will then add my first layer of treatment (1" Linacoustic RC on side walls up to ear level and 1" on front wall floor to ceiling) and take another measurement. THEN I will add bass traps in the four corners and measure again! Should be fun. This is a few weeks out and I have not yet purchased the BFD, but I think it is inevitable that I will want it- what do you think?


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## brucek (Apr 11, 2006)

> Would you recommend not using the YPAO at all?


Internal processor EQ can be beneficial. My comments on mains EQ were targetted toward the addition of an equalizer in the analog mains chain - which usually results in nothing more than extra noise.

There have been members here who have used processor EQ (such as YPAO) and run it first, then added BFD equalization. This would seem like a good way to go.



> I have not yet purchased the BFD, but I think it is inevitable that I will want it- what do you think?


Not many get away without it. You're wise to do your treatment first and then measure before purchasing a BFD. You may not need one...

brucek


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

> but what about the high end? Same process?


Generally if your mains sound balanced, you’ve already achieved the house curve, merely by selecting speakers that are a good match for your room (see Part 2 of our house curve sticky thread ). If you feel things aren’t quite right, you can use the basic tone controls to say, reduce the highs if things sound a little bright, or increase them if things sound a little dull.



> 2. Once you have calibrated for your House Curve, how do you match the sub to the fronts so the house curve is consistent into the highs?


At that point, you can simple use one of the calibration discs like AVIA, or (as brucek noted) adjust to taste.



> I have a Yamaha 5790 with the YPAO feature which will adjust for the mains/surrounds. YPAO has different settings which may be interesting. You can allow it to self-calibrate as a Parametric EQ or you can adjust each channel via 7-Band Graphic EQ. Would you recommend not using the YPAO at all?


I don’t see any reason not to use it. You can always bypass it if you think it’s not performing well. REW would help you measure “before and after” results. You will get the best results with the parametric EQ manually by using REW. Without that, it’s mostly guess work, unless you have a really keen and finely-tuned ear.

Regards,
Wayne


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## Guest (Sep 5, 2006)

Thanks, Wayne- Good information.

I have an external sound card on the way and have already downloaded REW.

I am just about ready to sheetrock the HT room- should be able to take some measurements in the next few weeks! Then I can decide whether or not the BFD will be a necessity!

Ryan


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