Signal Chain Question

**savior sound** · **03-30-09, 09:39 AM**

OK, here is my setup. Onkyo TX-SR806 AVR w/Audyssey MultEQ (Dynamic EQ), Klipsch RF-82 (dual 8" woofer) towers - bi-amped because I'm only runing 5.1, Klipsch (12"/350 Watt) RW-12d sub and matching Klipsch center & surrounds. I am now going to add a BFD. I am using REW w/RS SPL meter.

Here are my questions (first two of many more, I'm sure):

1) Do I run Audyssey first and let it get as close as it can and then setup BFD?
2) Do I run REW through AVR to get the bass from L/R towers in the reading?

Thanks

Steve

**tonyvdb** · **03-30-09, 11:34 AM**

1) Yes, run Audyssey first.
2) Yes, run it through the AVR but in order to test only the sub you will need to disconnect your speaker wires to the mains.

**Wayne A. Pflughaupt** · **03-30-09, 11:40 AM**

Quote:

savior sound wrote:

2) Do I run REW through AVR to get the bass from L/R towers in the reading?

Adding a bit to what Tony said, after you've EQ'd the sub you'll want to add the L/R towers and run REW with both sub and L/R. So yes, you want to run REW through the receiver.

Regards,
Wayne

**savior sound** · **03-30-09, 06:03 PM**

Ok, I ran Audessey first, then I ran REW with sub only (main/towers turned all the way down), loaded filters to BFD, re-ran REW with mains on and I am now trying to adjust filters and add some gain to some weak freqs. to get a smoother graph. Does this sound like the proper order to go?

Should I now re-run Audessey, now that I am closer to flat in the low end range?

**brucek** · **03-30-09, 06:06 PM**

Quote:

Should I now re-run Audessey, now that I am closer to flat in the low end range?

No. Not unless you want to go through the whole routine again.

brucek

**tonyvdb** · **03-30-09, 06:09 PM**

Quote:

savior sound wrote:

Ok, I ran Audessey first, then I ran REW with sub only (main/towers turned all the way down), loaded filters to BFD, re-ran REW with mains on and I am now trying to adjust filters and add some gain to some weak freqs. to get a smoother graph. Does this sound like the proper order to go?

Im fairly sure that is correct.

Quote:

Should I now re-run Audessey, now that I am closer to flat in the low end range?

No once Audessey has be run dont run it again or you will run the risk of it over riding the filters you are adding with the BFD.
How many positions did you test when you ran Audessey You should do at least 5, the more the better all 8 is the bast way to get good results.

**Wayne A. Pflughaupt** · **03-30-09, 06:16 PM**

Quote:

savior sound wrote:

Ok, I ran Audessey first, then I ran REW with sub only (main/towers turned all the way down), loaded filters to BFD, re-ran REW with mains on and I am now trying to adjust filters and add some gain to some weak freqs. to get a smoother graph. Does this sound like the proper order to go?

Generally yes, but it sounds like you added the mains before you were finished equalizing the sub. Just make sure you don't try to boost any nulls, which are typically recognizable as very narrow and very deep depressions. Likewise, don't try to apply any filters to any problems you see above the crossover frequency.

Regards,
Wayne

**savior sound** · **03-30-09, 06:48 PM**

Thanks, I was trying to address some nulls and playing with 90Hz while my x-over point is 80 Hz.

But should I not have the mains on while EQing the sub? Don't I want the low end response as smooth as possible (with woofers in towers engaged)?

**savior sound** · **03-30-09, 07:03 PM**

Next question. Am I trying to get the graph of my freq. response and my inverted filter response to match up by changing filter specs.?

**Wayne A. Pflughaupt** · **03-30-09, 07:07 PM**

Quote:

savior sound wrote:

Thanks, I was trying to address some nulls and playing with 90Hz while my x-over point is 80 Hz.

But should I not have the mains on while EQing the sub? Don't I want the low end response as smooth as possible (with woofers in towers engaged)?

Sure, but you want to be able to tell what you're seeing comes from the sub vs. what the mains add, since it's only the sub that you're equalizing. The mains are added to help get a blend between the two, and to specifically deal with any anomalies that might appear in the region of the crossover frequency. This is accomplished by adjusting the sub's phase control and/or perhaps some additional minor filtering.

Regards,
Wayne

**Wayne A. Pflughaupt** · **03-30-09, 07:08 PM**

Quote:

savior sound wrote:

Next question. Am I trying to get the graph of my freq. response and my inverted filter response to match up by changing filter specs.?

I'm afraid you lost me with that one...

Regards,
Wayne

**brucek** · **03-30-09, 07:10 PM**

Quote:

Next question. Am I trying to get the graph of my freq. response and my inverted filter response to match up by changing filter specs.?

No, the goal is to get the corrected line as close to the target line as possible.

Once you think the filters will accomplish that, you enter them into the BFD and measure to see how close you came.

brucek

**savior sound** · **03-30-09, 07:15 PM**

On REW's graph (filter adjust tab) I can see the results of my measurements taken without any filters on. After assigning filters to the peaks that were found I ticked the "Filters" and the "Invert filter responses" boxes and then I'm adjusting the filter freq, gain and bw/60 to try to get a good overlay of the two. Does this make sense?

**savior sound** · **03-30-09, 11:00 PM**

Should I be able to come closer than this?

**brucek** · **03-30-09, 11:23 PM**

Quote:

Should I be able to come closer than this?

Yes, but in the end, as I indicated in my post above, the goal is to get the corrected line as close to the target line as possible.. The target is the blue solid line and the corrected response is the red dotted line. You need to do more work to get the corrected line closer to the target.

BTW, when you take your measurements you should try for a target SPL level of 75dBSPL. You're measuring too high. Also, post your graphs using the standard axis of vertical = 45dB-105dB and horizontal = 15Hz-200Hz.

brucek

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