Advice on HT audio setup

**savior sound** · **04-04-09, 09:36 AM**

Please be patient with me guys as I am trying to figure things out on my own (search feature/other forums) but I need some advice getting my audio setup in a new home theater setup. I will list the things I've done so far and if anything is incorrect or missed please let me know.

1. Ran Audessey MultEQ all six positions on Onkyo 806 - which leads me to my first question - Audessey got my speaker distances right on the money for all of my speakers except the sub. The mains and sub are 8.5' away and it set my AVR to 14' for the sub. I read to add 1' of distance for BFD use. Should I set sub to 9.5'? Or add a foot to what setup set it to 15' (14'+1')?

2. I changed x-over freqs. on center and surrounds to 80 Hz - it had center set to 40 Hz and surrounds to 50 Hz. I left the mains set to full band but I am wondering if I should set them to 40 Hz (lowest choice available)

3. Set sound card input/outputs, Calibrated sound card and loaded file, Loaded .cal file for RS 33-2050 meter I'm using, calibrated SPL meter level Question: Should meter be set to 70 or 80 db range for all of this?

4. Set target level to 75.1 db and measured just mains (Klipsch RS-82's - dual 8" woofers) and got this

Two questions, should I crossover mains at 40 Hz like I was thinking and what is that dip at 61 Hz? It is more than a 30 db difference from the peak at 48 Hz. There is a pretty bad dip at 96 Hz as well. Is this typical? I'm not sure where the internal x-over point is on the towers. I have to believe it would be pretty high since they are only 2-way speakers with 2 8's and a horn driver.

I'm going to start working on EQing just the sub now to see what I can come up with. Meanwhile any comments, advice, suggestions would be greatly appreciated.

Thanks guys

Steve

How do I get the graph to show up so big and clear like others I've seen? Sorry (newbie)

**brucek** · **04-04-09, 10:45 AM**

Quote:

Should I set sub to 9.5'? Or add a foot to what setup set it to 15' (14'+1')?

If Audessey set the sub to 15', then it arrived at that value while the BFD was in the chain. So, the delay in the BFD has already been accounted for.

Quote:

I changed x-over freqs. on center and surrounds to 80 Hz - it had center set to 40 Hz and surrounds to 50 Hz. I left the mains set to full band but I am wondering if I should set them to 40 Hz (lowest choice available)

I wouldn't leave the mains full range. Too much overlap with the sub.

Quote:

Should meter be set to 70 or 80 db range for all of this?

The RS meter should be set (and left) at 80 range. If used at 70, the output would clip when measuring.

Quote:

what is that dip at 61 Hz?

A reflection that cancels the mains signal as it reaches the mic. Move the speaker(s) or listening position. Test each main separate to determine if it's one or both causing the problem.

Quote:

How do I get the graph to show up so big and clear like others I've seen?

Attach the file to your post, or use simple IMG tags as the reference.

brucek

**savior sound** · **04-04-09, 11:02 AM**

Thanks for the answers brucek.

So leave the 14' value that Audessey set? The sub is actually 8.5' from mic.

I will take your advice and crossover mains at 40Hz (or more?).

I set the mic/meter pointed straight up about 42" off of the floor at my main listening position. Is this correct?

Here is my first measurement sub only. I initially had target set to 76 db. As you can see I still have some problems in the 60's! I will try moving the sub to see if that will help any. Also thinking of bass trap for the one corner that I am able to put one.

**brucek** · **04-04-09, 12:29 PM**

Quote:

The sub is actually 8.5' from mic.

Physically it is, but acoustically the best distance (to obtain the correct phase) is the distance that the auto-eq system sets.

Quote:

I set the mic/meter pointed straight up about 42" off of the floor at my main listening position. Is this correct?

Yes, but tilted toward the mains front at about a 10-20 degree angle.

Quote:

Here is my first measurement sub only.

You're using LINear graph mode. Switch to the proper LOGarithmic mode. Use the Freq Axis icon in the top corner area of REW.

When measuring subs, use a low and upper limit in REW of 0Hz-200Hz. When displaying a sub graph use a horizontal scale of 15Hz-200Hz.

brucek

**savior sound** · **04-04-09, 03:37 PM**

Thanks again for the feedback. Should I be smoothing these graphs as well?

**brucek** · **04-04-09, 03:48 PM**

Quote:

Should I be smoothing these graphs as well?

No, smoothing is reserved for full range measurements to remove the comb filtering effect, so as to reveal the underlying trend of the signal.

brucek

**savior sound** · **04-04-09, 04:09 PM**

OK, I've been moving my sub all over the place and found that centered under my center channel speaker and about 7" out from the wall got the least 60-70Hz dip. Then I changed the sub distance on my AVR from 14' to 13.5' because this pacement is about 6" closer than when I ran auto-eq. earlier. Here are the differences in freq. response. Which should I use? Also, should I be concerned with the new dip created at about 113 Hz? or not worry because it is beyond x-over point.

**savior sound** · **04-04-09, 05:35 PM**

All of the sudden my SPL level is 64 db in a perfectly quiet room. It was more like 44-49 db before. When I unplug everything REW's meter reads around 32 and jumps up to 64 when I plug in RS mic/meter. It just started this. The RS meter dosen't show anything (set to 60db range) until I plug in the cable to sound card, then it jumps to 64. I will try to put together another cable but I think I may have to head the Radio Shack just to try it. Any suggestions?

**dewd** · **04-06-09, 10:32 AM**

Quote:

savior sound wrote:

OK, I've been moving my sub all over the place and found that centered under my center channel speaker and about 7" out from the wall got the least 60-70Hz dip. Then I changed the sub distance on my AVR from 14' to 13.5' because this pacement is about 6" closer than when I ran auto-eq. earlier. Here are the differences in freq. response. Which should I use? Also, should I be concerned with the new dip created at about 113 Hz? or not worry because it is beyond x-over point.

You have to re-run Audyssey each time you move your speakers/sub. I take it from your post that you only changed the distance?

Also, moving the sub after running Audyssey will skew your results. You should find the best place for the sub with the EQ disabled, then run Audyssey and take your measurements.

**savior sound** · **04-06-09, 08:08 PM**

Dave

No, I only ran Audessey once.

You are saying I should disable EQ altogether, find the best sub location without it, then run auto-EQ, then take some measurements with (Audessey)EQ engaged but no BFD (of course) and then set my filters?

**dewd** · **04-06-09, 08:15 PM**

Sort of....

You should turn off all EQ. Find the best place for your sub. Then, if you want to use BFD, configure that first. Lastly, run Audyssey.

The reason for this... When you run Audyssey, it corrects for the speakers as they are at the time you run it. If you move a speaker, the correction stays as if you did not move it. In other words, the correction is now wrong and your measurements will be wrong, too.

The reason you setup BFD first is so Audyssey can set the proper distance (delay).

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