First run with REW... advice and tips please :) - AVS Forum
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post #1 of 146 Old 03-23-2012, 09:37 PM - Thread Starter
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These are my first few measurements with REW in my HT. No calibration what so ever has been done yet except for level matching speakers. No Aydyssey and no Behringer DSP filters either. I'm sure these graphs won't mean too much yet, but I wanted to post them anyway because it was fun :P

No room treatments have been applied either, superchunk bass traps are waiting to be installed though

This first one is full range from 10hz - 10khz, crossing over to sub at 120hz and speakers set to small...



These next two are subs only, 10hz - 100hz, no tweaks at all, just a baseline run. The first one is front center LP and 2nd is rear center LP...





Marantz SR5005 AVR
Behringer EP4000 amp
Behringer FBD (no filters yet)
(4) FiCar Audio IB3 18's in a line array on front wall
DIY Econowave LCR speakers

Once again, these graphs won't mean much but it's a start. Any tips and tricks you can jot down would be fantastic...

My only questions so far are...

The R-Shack meter feeds a bit of static into the sound card input that I hear through the avr, is this normal?

Should I consider upgrading to a Dayton Omni Mic?

How about the sound card, right now it's a basic USB SoundBlaster sound card.

Also, how do I word this... Right now, I have the sub levels in the AVR set to 0 (neutral) and I turned up the amp gain enough to get 75db out of the subs with test tones (this is when I was level matching speakers). This leaves the amp gains at about 1/3 the way up. For ease of asking the question, lets say the amp could put out 900 watts at full gain, with the amp gain at only 1/3, is the amount of power the amp is able to send to the subs only 300 watts no matter how strong the signal being sent to the amp from the AVR is?

Gosh I hope thats easy to follow
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post #2 of 146 Old 03-24-2012, 03:28 AM
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Quote:
Originally Posted by Digital_Chris View Post

These are my first few measurements with REW in my HT. No calibration what so ever has been done yet except for level matching speakers. No Aydyssey and no Behringer DSP filters either. I'm sure these graphs won't mean too much yet, but I wanted to post them anyway because it was fun :P

No room treatments have been applied either, superchunk bass traps are waiting to be installed though

Looks like that money won't be wasted.

Quote:


Marantz SR5005 AVR
Behringer EP4000 amp
Behringer FBD (no filters yet)
(4) FiCar Audio IB3 18's in a line array on front wall
DIY Econowave LCR speakers

Once again, these graphs won't mean much but it's a start. Any tips and tricks you can jot down would be fantastic...

My only questions so far are...

The R-Shack meter feeds a bit of static into the sound card input that I hear through the avr, is this normal?

A little hiss won't be a problem.

Quote:


Should I consider upgrading to a Dayton Omni Mic?

I'm a happy user of Behringer ECM 8000s.

Quote:


How about the sound card, right now it's a basic USB SoundBlaster sound card.

If you upgrade the mic you'll need a mic preamp with phantom power. Usually, people accomplish this by getting a USB interface with mic preamps built in.

Quote:


Also, how do I word this... Right now, I have the sub levels in the AVR set to 0 (neutral) and I turned up the amp gain enough to get 75db out of the subs with test tones (this is when I was level matching speakers). This leaves the amp gains at about 1/3 the way up. For ease of asking the question, lets say the amp could put out 900 watts at full gain, with the amp gain at only 1/3, is the amount of power the amp is able to send to the subs only 300 watts no matter how strong the signal being sent to the amp from the AVR is?

Gain settings don't affect the actual power output of an amplifier. However, you can set an amp's gain low enough that you won't be able to drive the amp hard enough to exploit its potential.
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post #3 of 146 Old 03-25-2012, 11:18 PM - Thread Starter
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Originally Posted by arnyk View Post

Gain settings don't affect the actual power output of an amplifier. However, you can set an amp's gain low enough that you won't be able to drive the amp hard enough to exploit its potential..

How would you suggest I find out where I should set my amp gains in a way that won't hold that woofers back from their full potential if called for?
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post #4 of 146 Old 03-26-2012, 05:40 AM
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Originally Posted by Digital_Chris View Post

How would you suggest I find out where I should set my amp gains in a way that won't hold that woofers back from their full potential if called for?

All the way up. If there is noise or other inconvenient results, back them all off an equal amount at the same time, until the desired result is obtained.

That's the best I can do from thousands of mile away. ;-)
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post #5 of 146 Old 03-26-2012, 08:09 AM
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Quote:
Originally Posted by Digital_Chris View Post

Also, how do I word this... Right now, I have the sub levels in the AVR set to 0 (neutral) and I turned up the amp gain enough to get 75db out of the subs with test tones (this is when I was level matching speakers). This leaves the amp gains at about 1/3 the way up. For ease of asking the question, lets say the amp could put out 900 watts at full gain, with the amp gain at only 1/3, is the amount of power the amp is able to send to the subs only 300 watts no matter how strong the signal being sent to the amp from the AVR is?

Don't worry about. Your goal should be to optimize the output of the subs for the room to match up with the speakers to produce a fairly flat response. That's why you got the EQ, right?

If you need more help configuring your subs, you should share your graphs in the AVS subwoofer forum. There are people there who play with REW and their subs all day long

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post #6 of 146 Old 03-26-2012, 04:23 PM
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Quote:
Originally Posted by Digital_Chris View Post

These are my first few measurements with REW in my HT. No calibration what so ever has been done yet except for level matching speakers.

did you calibrate the sound-card?

Quote:
Originally Posted by Digital_Chris View Post

These next two are subs only, 10hz - 100hz, no tweaks at all, just a baseline run. The first one is front center LP and 2nd is rear center LP...

it's worthwhile to upload the measurement file than posting screenshots (www.sendspace.com)

you need to measure one speaker (source) at a time, as you will not be able to determine much with multiple sources at this time..

primarily concerned with:
  • -waterfall plot 0-300hz (frequency response in modal region + LF decay times)
  • -Envelope Time Curve (ETC) for the specular region.

Quote:
Originally Posted by Digital_Chris View Post

Once again, these graphs won't mean much but it's a start. Any tips and tricks you can jot down would be fantastic...

My only questions so far are...

The R-Shack meter feeds a bit of static into the sound card input that I hear through the avr, is this normal?

Should I consider upgrading to a Dayton Omni Mic?

yes:
http://www.parts-express.com/pe/show...number=390-801

and you can get the cal file here;
http://www.daytonaudio.com/index.php...icrophone.html

this will work for a USB sound-card + pre-amp:
http://www.bhphotovideo.com/c/produc..._Dual_Pre.html
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post #7 of 146 Old 03-29-2012, 10:44 PM - Thread Starter
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Quote:
Originally Posted by localhost127 View Post

did you calibrate the sound-card?

Yes, I meant the system hasn't been calibrated yet except for level matching the speakers.

Quote:
Originally Posted by localhost127 View Post

it's worthwhile to upload the measurement file than posting screenshots (www.sendspace.com)

Will do once I take some worthwile measurements.

Quote:
Originally Posted by localhost127 View Post

you need to measure one speaker (source) at a time, as you will not be able to determine much with multiple sources at this time..

primarily concerned with:
  • -waterfall plot 0-300hz (frequency response in modal region + LF decay times)
  • -Envelope Time Curve (ETC) for the specular region.

I need to run each speaker at a time with ALL types of measurements and not just ETC? Aye yigh yigh.. Also, I haven't figured out how to turn my graphs into waterfalls and the such.. I'll go through the REW help files again I guess.. I didn't see any detailed how to's yet.


Quote:
Originally Posted by localhost127 View Post

yes:
http://www.parts-express.com/pe/show...number=390-801

and you can get the cal file here;
http://www.daytonaudio.com/index.php...icrophone.html

this will work for a USB sound-card + pre-amp:
http://www.bhphotovideo.com/c/produc..._Dual_Pre.html

Thanks for the links, looks like the Dayton is on backborder till 4/10 though, dang. Is the Behringer ECM8000 worth the extra $15 or just wait for the Dayton? Any measurements you recommend I take with the current SPL meter I have in the mean time?

Another thing, where do I start here in this whole measurement process... When do I run Audyssey? I may have stated this in another thread but I'm not looking to make this a painfully long process because I'm afraid it won't be fun so I'm not sure what order things should take place.

If you have any more questions that will help you answer MY questions, please ask
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post #8 of 146 Old 03-29-2012, 11:15 PM
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Waterfalls and ETC are just different views of the same measurement, so you don't need to measure them separately.

Turn on smoothing (1/6 octave, say) for the full range measurements; leave it off for sub measurements.

For full range, take it up to 20k; for subs, 10-200 or thereabouts.
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post #9 of 146 Old 03-30-2012, 01:20 AM - Thread Starter
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Quote:
Originally Posted by Brad Horstkotte View Post

Waterfalls and ETC are just different views of the same measurement, so you don't need to measure them separately.

Turn on smoothing (1/6 octave, say) for the full range measurements; leave it off for sub measurements.

For full range, take it up to 20k; for subs, 10-200 or thereabouts.

So when I do a sweep, I'm able to view each of those graphs afterward? I didn't realize that. I thought I had to do a different test for each type of graph, good to know!

Thanks for the smoothing advise along with the frequency limits
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post #10 of 146 Old 03-30-2012, 05:50 AM
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Quote:
Originally Posted by Brad Horstkotte View Post

Waterfalls and ETC are just different views of the same measurement, so you don't need to measure them separately.

yes.
a waterfall is to display the CSD of the modal region - frequency response and LF decay times. the ETC is the time-domain measurement for the specular region - to identify how specular energy is impeding the listening position. from the direct signal, to sparse high-gain reflections incident from room boundaries, to later-arriving reflections, to the eventual decay of the energy until it is fully damped. gain with respect to time.

however, the ETC can also be used to identify coupling issues - as one may have a scenario where energy is present BEFORE the direct signal on the ETC, which may indicate a measurement error! but in actuality, if there is coupling issues, then the speed of sound will be faster in the solid than in air and thus the energy will arrive before the direct signal propagates through the air/medium.

and as the ear-brain is unable to resolve indirect signals arriving within the haas interval, such measurements with the ETC are required in order identify how such energy impedes the listening position.

another highly important factor is to utilize the ETC to identify edge diffraction from the speaker cabinet or objects placed near-by the speaker.

the ETC is a measurement tool to use to view the specular region such that you can modify the room to meet YOUR specific specular criteria (eg, the total specular response you are wishing to achieve).

Quote:
Originally Posted by Brad Horstkotte View Post

Turn on smoothing (1/6 octave, say) for the full range measurements; leave it off for sub measurements.

no. why?
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post #11 of 146 Old 03-30-2012, 05:50 AM
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Quote:
Originally Posted by Digital_Chris View Post

So when I do a sweep, I'm able to view each of those graphs afterward? I didn't realize that. I thought I had to do a different test for each type of graph, good to know!

Thanks for the smoothing advise along with the frequency limits

do NOT band-limit the sweep.
and once the sweep is performed, the data can be generated by viewing the different tabs within REW.
you will have to modify the default waterfall settings in REW.

again, it is best to upload the measurement file to www.sendspace.com vs posting screenshots here .

measure one source at a time!!! - unless you are a fan of multi-variable calculus: (A*B*C == 5; solve for B)
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post #12 of 146 Old 03-30-2012, 07:08 AM
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I should have clarified - turn on smoothing for full range FR views only
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post #13 of 146 Old 03-30-2012, 07:37 AM
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Quote:
Originally Posted by Brad Horstkotte View Post

I should have clarified - turn on smoothing for full range FR views only

unless making brochures or marketing material, why would you enable smoothing when making measurements of the acoustical space? isn't the goal of measurements in this context to identify issues and anomalies?
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post #14 of 146 Old 03-30-2012, 08:31 AM
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unless making brochures or marketing material, why would you enable smoothing when making measurements of the acoustical space? isn't the goal of measurements in this context to identify issues and anomalies?

He's not suggesting enabling smoothing WHILE making measurements (cna you even do that with REW?), just for viewing the frequency response of the measurement afterwards. IE, for 20-20KHz FR graph, viewing at 1/6 +/- allow you to see overall trend vs. all the clutter from no smoothing.
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post #15 of 146 Old 03-30-2012, 10:27 AM
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Quote:
Originally Posted by fotto View Post

He's not suggesting enabling smoothing WHILE making measurements (cna you even do that with REW?),

that's not what i implied.

Quote:
Originally Posted by fotto View Post

just for viewing the frequency response of the measurement afterwards. IE, for 20-20KHz FR graph, viewing at 1/6 +/- allow you to see overall trend vs. all the clutter from no smoothing.

that's fair,of course! he just didn't detail that in his original post,
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post #16 of 146 Old 04-01-2012, 09:46 PM - Thread Starter
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Got it. Now where do I start with the whole testing process... When should I run Audyssey, before or after all of the REW sweeps and treatment placement? Should I start by placing my bass traps, start with first reflections? I'm ready to do testing this week but not sure where I should start, if it even matters
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post #17 of 146 Old 04-02-2012, 04:16 AM
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if you're looking to measure the bounded acoustical space and identify issues the room is imposing, then you would not want to run the sweeps with any EQ systems running (such as audyssey).

this will give you a "base-line" starting point.

it is always best to take measurements without any modifications to the room or 'treatments' applied. this allows you to first identify what may be characterized as a "problem" based on your design goals before blindly applying treatment. eg, you can measure to identify ACTUAL high-gain indirect reflection paths and surgically apply broadband absorption to attenuate, vs blindly applying absorbers at any and all "first reflection points".
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post #18 of 146 Old 04-02-2012, 08:32 AM
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Chris, I believe the goal is to get the room in the best "shape" possible from an audio perspective (including sub/speaker positioning, treatments) and THEN run Audyssey. This will make it's job much easier.
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post #19 of 146 Old 04-02-2012, 01:11 PM - Thread Starter
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Quote:
Originally Posted by fotto View Post

Chris, I believe the goal is to get the room in the best "shape" possible from an audio perspective (including sub/speaker positioning, treatments) and THEN run Audyssey. This will make it's job much easier.

I figured that would be the way to go, thanks
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post #20 of 146 Old 04-03-2012, 12:31 AM - Thread Starter
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Well, since the Dayton mic was backordered till the 10th, I decided to order the Behringer ECM8000 mic from BHPhotoVideo, the price was justified because of the free and quick shipping (NY to CT), plus, I grabbed the ACT box you recommended, local.

Is there a calibration file somewhere for this mic as well?

Also, just for haha's, I ran Audyssey with the room as is, no wall or corner treatment and the system still sounds, well, boring. I was in no way expecting Audyssey to work miracles with no room treatment but for comparison, my living room still sounds better (cleaner and more dynamic) with no wall or corner treatments, a set of Paradigm half size towers with the tweeter a foot above ear level, phantom center and a corner loaded table tuba. The living room also has hardwood floors but a full size sectional, plus, it is very close to the back wall (within 2').

Either way, I really hope some room treatment and EQ can get this theater sounding like it's supposed to, I just thought as is it would still sound very nice in the mean time.

Just out of curiosity, why would Audyssey set all of my speakers' trim down in the AVR a good 4-5db across the board? It also set my sub level down about 5db from the rest of the speakers (measured via SPL meter, not trim level). It set my LCR crossover at 40hz and surrounds at 60hz. Is this a good thing?

Again, nothing to think lots over, just did it for haha's untill my gear came.

Any thoughts on it though would be cool, I always love to learn why stuff does certain stuff
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post #21 of 146 Old 04-03-2012, 05:18 AM
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Quote:
Originally Posted by Digital_Chris View Post

Is there a calibration file somewhere for this mic as well?

i don't have that mic - let me try searching...
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post #22 of 146 Old 04-03-2012, 06:25 AM
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Herb at Cross Spectrum sells calibrated ECM8000 and EMM-6 in the $70-$80 range here http://www.cross-spectrum.com/measur...behringer.html
I got the EMM-6 with "Basic +" calibration.
Based on other comments, I don't see a "stock" cal file out there for the ECM8000 (you can probably find one but accuracy for your particular mic is another story).
If you want it accurate, I believe you can ship to Cross Spectrum to test for calibration file, or return your current one and just buy a calibrated one from Herb.
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post #23 of 146 Old 04-03-2012, 07:01 AM
 
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One would most likely want to have the individual Behringer mic calibrated, as Herb at Cross Spectrum has reported on the rather dramatic variability between individual units such that a generic calibration file would not be of much value.
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post #24 of 146 Old 04-04-2012, 02:12 PM - Thread Starter
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Good news! Cross-Spectrum is pretty much down the street from me, within 20min or so!

I received the ECM8000 today, I'll call them tomorrow to schedule a calibration
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post #25 of 146 Old 04-04-2012, 02:21 PM
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There is a generic calibration file for the ECM8000 on the REW site:

http://www.hometheatershack.com/foru...oads-page.html (about half way down)

(as mentioned, not as good as one specific to the mic, but better than nothing)
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post #26 of 146 Old 04-04-2012, 05:04 PM - Thread Starter
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Ahh, thank you very much Brad. I didn't get around to that part of the site yet

I will try out some measurements with that cal file and see what other REW users think.

Thanks again
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post #27 of 146 Old 04-12-2012, 06:00 PM - Thread Starter
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Here is an update to show measurements with my new ECM8000 mic and ART dual pre. I started off with the LF measurements first (10-200hz) so I could see how the room acts with and without the superchunk bass traps. I will try to be as thorough as possible. Gear is listed below...

Marantz SR5005 AVR
Behringer DSP1124P
Behringer EP4000
(4) FiCar 18" IB Drivers in a Line Array
LCR Econowave Speakers Flush Mounted
Behringer ECM8000 mic with generic cal file from this site
ART Dual Pre sound card

AVR Settings:

Bass Settings: SW Mode - LFE (also have a choice for LFE+Main)
LPF for LFE - 120hz

Speaker Config : All speakers set to small

Crossover Freq : Front/Center - 60hz
Surround/Surround Back - 80hz

Room Dimensions are 18 x 10.5 x 7

Front eyes - roughly 9.5' from screen

Rear eyes - roughly 12.5' from screen

Subs in Line Array on lower portion of front wall

I took a measurement at front center seat and rear center seat to get a baseline of the rooms response. As figured, they both sound different, the LFE at the rear seats is stronger and more tactile while the front seats, not as much. I was hoping the superchunk bass traps would help with this... to a point I guess they did, not NEARLY as much as hoped..

Front Center Seat before Superchunks



Front Center Seat after Superchunks



Overlayed



Rear Center Seat before Superchunks



Rear Center Seat after Superchunks



Overlayed



After all graphs were taken, the db levels seem to be off, I'm guessing that the sound card level or avr was a little off? If you recommend new measurements, I can do that.

The biggest let down is the difference between no bass traps and both superchunks. Unfortunately I don't have the room for superchunks up front but I was hoping the two in the rear would make a noticeable difference, I was let down

The superchunks are about 5.5' tall, a few inches off the floor (to match my wall panels), to about a foot from the ceiling. I can take pictures if you would like. They are 36" faced and filled with pink fluffy insulation.

The only big difference was in the rear seat at about 66hz, it took about 15db out of the humongous dip, other than that, no big change

Below is the link to the actual REW files so you can take a look for yourself. If you want pictures of the room, I can do that as well. All feedback is encouraged

http://www.sendspace.com/filegroup/g...b4biRvHXdjkKhF
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post #28 of 146 Old 04-12-2012, 08:54 PM
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Quote:
Originally Posted by Digital_Chris View Post

The biggest let down is the difference between no bass traps and both superchunks. Unfortunately I don't have the room for superchunks up front but I was hoping the two in the rear would make a noticeable difference, I was let down

Don't let amirm see this or we'll never hear the end of it... but yes, I have found that the biggest and most influential impact on the lower Hz range is speaker and subs and LP placement and setup. (distance, crossover, EQ etc)

No doubt that more of those bass traps will help some, but it really needs to be a combination of that and speaker placement and setup in the room as well.
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post #29 of 146 Old 04-13-2012, 01:27 AM - Thread Starter
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Quote:
Originally Posted by dragonfyr View Post

Get the mic calibrated!
The Behringer mics exhibit far too much variability to use a generic calibration file!

How much is far too much? Far too much for you? Obviously. Far to much for everybody else? That's a bit of an assumption.

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Originally Posted by dragonfyr View Post

And forget smoothing!
We don't care how pretty the full range frequency response looks - it WILL have comb filtering!

Who's we?

Quote:
Originally Posted by dragonfyr View Post

And forget Audyssey for now!
It is not even a consideration until AFTER you address all of the other factors.

This has already been addressed.

Quote:
Originally Posted by dragonfyr View Post

Measure each source individually with the mic located at the listening position for ALL measurements (imagine where the center of your head would be located) with the mic remaining in the EXACT SAME position for EVERY measurement.
This is critical! One way to mark this position is to hang a plumb bob from the ceiling to determine the precise location of the capsule so that the mic can be replaced there for future reference (and of course pull the plumb bob out of the way until needed!).

How critical is it really? I think you're talking to the wrong person about perfection when I don't have the room or gear placement that will accept perfection in the first place.

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Originally Posted by dragonfyr View Post

You will run sweeps for the subs (separately and both (if more than one) together), and for each separate speaker.

I thought I was running full range sweeps ALL the time... now you say to run sweeps for the subs separate from each individual speaker? Also, my gear list mentions (4) IB subs in a Line Array on the front wall and a Behringer EP4000 amp driving them... not sure if you skipped over that part.

Quote:
Originally Posted by dragonfyr View Post

And no, 2 small porous bass traps will not do much! No surprise here!
Your first and primary correction will be listening position adjustment forward or back in order to locate the listening position outside of the nulls - between nulls and peaks while retaining left-right symmetry!

I didn't realize Superchunks were considered "small" bass traps. Also, listening position cannot be changed. Not that critical to me anyway.

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Originally Posted by dragonfyr View Post

In fact, if you want to save a bit of time, you might focus on mapping the listening area - create a literal grid on graph paper for the region surrounding the listening area and make incremental measurements, say each 1/2 foot, for about 3 foot in front of and behind the listening position. You will relocate the listening position to the point where it is best in-between the nulls.

And one might also get expectations in order: Traps (and EQ) reduce peaks, they do not remove nulls. And nothing 'removes' modal behavior.

How does bass trapping not remove nulls? It did for my rear seats.. Bass traps tame the reflecting bass which cause nulls when they colide with oncoming waves, no?

Bottom line is that I'm not asking for perfection, I'm just asking for some help on how to make the room sound better than it currently does... I would also like to ask you could not be so harsh with me... it's replies like yours that make me not want to continue down this road. I'm trying to have fun here.

Also, this is not meant to be taken with disrespect, but if you can't help me in any way other than achieving perfection, you will only be making this journey more complicated for me than it needs to be. I'm sorry.
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post #30 of 146 Old 04-13-2012, 01:32 AM - Thread Starter
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Quote:
Originally Posted by dragonfyr View Post

Get the mic calibrated!
The Behringer mics exhibit far too much variability to use a generic calibration file!

How much is far too much? Far too much for you? Obviously. Far to much for everybody else? That's a bit of an assumption.

Quote:
Originally Posted by dragonfyr View Post

And forget smoothing!
We don't care how pretty the full range frequency response looks - it WILL have comb filtering!

Who's we?

Quote:
Originally Posted by dragonfyr View Post

And forget Audyssey for now!
It is not even a consideration until AFTER you address all of the other factors.

This has already been addressed.

Quote:
Originally Posted by dragonfyr View Post

Measure each source individually with the mic located at the listening position for ALL measurements (imagine where the center of your head would be located) with the mic remaining in the EXACT SAME position for EVERY measurement.
This is critical! One way to mark this position is to hang a plumb bob from the ceiling to determine the precise location of the capsule so that the mic can be replaced there for future reference (and of course pull the plumb bob out of the way until needed!).

How critical is it really? I think you're talking to the wrong person about perfection when I don't have the room or gear placement that will except perfection in the first place.

Quote:
Originally Posted by dragonfyr View Post

You will run sweeps for the subs (separately and both (if more than one) together), and for each separate speaker.

I thought I was running full range sweeps ALL the time... now you say to run sweeps for the subs separate from each individual speaker? Also, my gear list mentions (4) IB subs in a Line Array and a Behringer EP4000 amp driving them... not sure if you skipped over that part.

Quote:
Originally Posted by dragonfyr View Post

And no, 2 small porous bass traps will not do much! No surprise here!
Your first and primary correction will be listening position adjustment forward or back in order to locate the listening position outside of the nulls - between nulls and peaks while retaining left-right symmetry!

I didn't realize Superchunks were considered "small" bass traps. Also, listening position cannot be changed. Not that critical to me anyway.

Quote:
Originally Posted by dragonfyr View Post

In fact, if you want to save a bit of time, you might focus on mapping the listening area - create a literal grid on graph paper for the region surrounding the listening area and make incremental measurements, say each 1/2 foot, for about 3 foot in front of and behind the listening position. You will relocate the listening position to the point where it is best in-between the nulls.

And one might also get expectations in order: Traps (and EQ) reduce peaks, they do not remove nulls. And nothing 'removes' modal behavior.

How does bass trapping not remove nulls? It did for my rear seats.. Bass traps tame the reflecting bass which cause nulls when they colide with oncoming waves, no?

Bottom line is that I'm not asking for perfection, I'm just asking for some help on how to make the room sound better than it currently does... I would also like to ask you could not be so harsh with me... it's replies like yours that make me not want to continue down this road. I'm trying to have fun here.

Also, this is not meant to be taken with disrespect, but if you can't help me in any way other than achieving perfection, you will only be making this journey more complicated for me than it needs to be. I'm sorry.
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