# My equalization/room look ok?



## thewire (Jun 28, 2007)

I did some testing at various volume settings on my receiver up until the setting was at 0. It has been setup using the auto setup and a digital SPL meter. I re-calibrated the SPL meter with REW for the final test that is the longest one shown. Any advise, questions or room treatment suggestions would be really great. I could also manually adjust my equalizer settings if you see where I should do that. I didn't use any filters. A hush box fan was running nearby above the mic and my computer was behind the couch in the back of the room. When I played nothing it kept reading the background noise at around -20db. If it looks wrong I will do it again but I would have to bring my computer in there again. I plan to once I figure out how to do a waterfall. I copied and pasted my notes and images bellow.
































































GEAR:

RADIO SHACK DIGITAL SPL METER (STEREO HEADPHONE JACK LEFT OUTPUT)
PIONEER VSX1012 THX SELECT RECIEVER 90 WATT x 6 AT TWEETERS
LIBERTY THX/MONSTER/BETTERCABLES CABLES
5 MARANTZ MA50 THX (EARLY GENERATION) MONO AMPS (+1 ON RESERVE)
DENON 5200 THX ULTRA 2 CHANNEL AMP

CRYSTAL AUDIO 12THX SUB
6 POLK RTI70 FLOOR STANDING
POLK CSI40 CENTER CHANNEL (TWEETER MOD)

ROOM:

CONCRETE/FRAMING/1 LAYER DRYWALL
13.5 X 20 X 7'4"
OUTDOOR CARPET NO PADDING SPEAKER PLATFORMS, STAGE, FLOOR, RISERS, HUSH BOX
REAR LEFT & RIGHT REAR SPEAKER PLATFORMS ARE BASS TRAPS
CEILUME CEILING TILES, GENERIC CEILING TILES @ LEFT AND RIGHT WALLS DE COUPLED WITH CARPET
NO MORE THAN 12" OF GENERIC TILE WIDTH (WIDTH VARIES)
ADJACENT ONE CLOSET & LOBBY WITH SEALED SOLID CORE DOOR
AC VENT /WALL HEATER/HUSH BOX FAN
TWO ROWS OF THREE SEATS

PROJECTION NEC 6PG+ CRT, TOSHIBA HD A30, FOUCS ENHANCEMENTS CENTERSTAGE 2,
106" DALITE HIGH POWER



MANUAL ROOM TEST RESULTS: 


31HZ-35HZ @ 85DB CEILING [MODERATE DISTORTION ISSUE]
70HZ-80HZ @ 101DB INTERNAL CEILING STRUCTURE [MINOR DISTORTION ISSUE]
45HZ DOOR [MAJOR DISTORTION ISSUE] (CORRECTABLE BY PULLING TIGHTLY SHUT)
APROX 47HZ @ 93DB INTERNAL BACK WALL [MINOR DISTORTION ISSUE]
57HZ-60HZ @ 98DB CEILING [MINOR DISTORTION ISSUE]
60HZ-63HZ @ 98DB CEILING [MODERATE DISTORTION ISSUE]
63HZ-67HZ @ 98DB [MINOR DISTORTION ISSUE]

MODERATE DISTORTION ISSUES MAY BE AUDIBLE
DURING MUSIC/MOVIES (OTHER FREQ MAY MASK THE ABILITY TO HEAR IT)


MORE:

USB VOLUME IS AT 0 - (BUT VARIED) EQUALIZER SETTINGS ARE SET AT ALL ADJUST- SETUP IS AUTO SETTING
ALL DB READING/FREQ RANGE ARE APROX AND WERE DONE USING THE SPL METER,
SPL METER MIC, AND REW (CONTINUED SEE TXT FILES AND IMAGES)

OCT 14, 2007

:reading::reading::reading:


----------



## Otto (May 18, 2006)

Hi there,

Your room looks great! But can you change your plot ranges? Usually, we're primarily interested in sub response because it's the most accurate to measure and what you'll be addressing with any parametric EQ. Can you change the axes to 15-200 Hz on the horizontal and 45 to 104 dB on the vertical?

Thanks and looks good!


----------



## thewire (Jun 28, 2007)

I reloaded my saved files figured out how to change the view and replaced the images. Sorry about that.


----------



## thewire (Jun 28, 2007)

the waterfall










room treatments? Change my crossover? Turn my sub up or down?


----------



## brucek (Apr 11, 2006)

Tremendous amount of noise in your impulse response. What does the impulse response look like when you measure a simple loopback cable? This will tell us if the computer is capable of a proper reading.

Always set the graphs to logarithmic - not linear.

Do a response with the sub only and the mains shut off. That way we can see if it tracks a decent target. 

Always test with the receiver in stereo with no effects or surround modes on.

brucek


----------



## thewire (Jun 28, 2007)

brucek said:


> Tremendous amount of noise in your impulse response. What does the impulse response look like when you measure a simple loopback cable? This will tell us if the computer is capable of a proper reading.
> 
> Always set the graphs to logarithmic - not linear.
> 
> ...


Something to do with my receiver and True HD audio made the power in my house go out twice possibly. The first time I had just switched audio to True HD. The second time I was turning down the volume about 10 seconds into the movie. Could be some sorta strange coincidence also. When I turned it on it had gone to a different input selection. I think I need to reset my 3 breakers (two dedicated circuits) to the theater every month much like we are supposed to for the hot tub. Or I am just loosing my marbles. Now that I know the left output works for the mic I went back and re-calibrated using that. The before results were read using the left with the mic but my auto-setup was done using the right on accident. I used the right because it would not give me a ambient noise error. I ignored it this time and the results were much more sensitive. It set my speakers to large. I will redo the test tonight and watch some movies to compare the difference. 

Also. Yes I had it set to dolby digital not stereo. I will try with the mains off as well. Crossover is at 50HZ. I will also set the graph to logarithmic as soon as I figure that out. the button pictured was not shown in my version and I had downloaded REW many months ago so I will download the latest version as well. Thank you for the tips.


----------



## thewire (Jun 28, 2007)

Using the tips I got I made corrections to the layout and made further notes. I also corrected the ceiling height. These results are now done both using the same input as with the setup. I did not turn off my mains because a 50hz crossover would limit these results. See the notes for the color key. With these results I hope to make improvements. 










all_energy_time.jpg









all_impulses2.jpg









all_mesured2.jpg









average.jpg









filter_adjust2.jpg









scope.jpg









waterfalll_standard2.jpg

- notes

GEAR:

RADIO SHACK DIGITAL SPL METER (STEREO HEADPHONE JACK LEFT OUTPUT)
PIONEER VSX1012 THX SELECT RECIEVER 90 WATT x 6 AT TWEETERS
LIBERTY THX/MONSTER/BETTERCABLES CABLES
5 MARANTZ MA50 THX (EARLY GENERATION) MONO AMPS (+1 ON RESERVE)
DENON 5200 THX ULTRA 2 CHANNEL AMP

CRYSTAL AUDIO 12THX SUB
6 POLK RTI70 FLOOR STANDING
POLK CSI40 CENTER CHANNEL (TWEETER MOD)

ROOM:

CONCRETE/FRAMING/1 LAYER DRYWALL
13.5 X 20 X 7'6"
OUTDOOR CARPET NO PADDING SPEAKER PLATFORMS, STAGE, FLOOR, RISERS, HUSH BOX
REAR LEFT & RIGHT REAR SPEAKER PLATFORMS ARE BASS TRAPS
CEILUME CEILING TILES, GENERIC CEILING TILES @ LEFT AND RIGHT WALLS DE COUPLED WITH CARPET
NO MORE THAN 12" OF GENERIC TILE WIDTH (WIDTH VARIES)
ADJACENT ONE CLOSET & LOBBY WITH SEALED SOLID CORE DOOR
AC VENT /WALL HEATER/HUSH BOX FAN
TWO ROWS OF THREE SEATS

PROJECTION NEC 6PG+ CRT, TOSHIBA HD A30, FOUCS ENHANCEMENTS CENTERSTAGE 2,
106" DALITE HIGH POWER



MANUAL ROOM TEST RESULTS: 


31HZ-35HZ @ 85DB CEILING [MODERATE DISTORTION ISSUE]
70HZ-80HZ @ 101DB INTERNAL CEILING STRUCTURE [MINOR DISTORTION ISSUE]
45HZ DOOR [MAJOR DISTORTION ISSUE] (CORRECTABLE BY PULLING TIGHTLY SHUT)
APROX 47HZ @ 93DB INTERNAL BACK WALL [MINOR DISTORTION ISSUE]
57HZ-60HZ @ 98DB CEILING [MINOR DISTORTION ISSUE]
60HZ-63HZ @ 98DB CEILING [MODERATE DISTORTION ISSUE]
63HZ-67HZ @ 98DB [MINOR DISTORTION ISSUE]

MODERATE DISTORTION issues may be audible to the human ear
during music/movies (other frequences may mask the ability for them to be heard)


MORE:

USB volume @ 0 - Equalizer settings are set to all adjust - Setup is auto-setting
All db reading/frequency ranges are approximate adn done using a digital SPL meter,
it's mic, and REW version 4.0 (See images)

COLOR REFERENCE:

Red

-12db @ receiver
-.04db high @ check level
SPL meter @ 75db uncorrected

Green 

-18 @ receever
-0.3db high @ check level
78db @ SPL meter uncorrected

Blue

-0db @ receiver
-0.1db high @ check level
SPL meter @ 87db uncorrected

Purple is average


OCT 15, 2007

- end notes


----------



## JohnM (Apr 11, 2006)

The scope plot shows heavy clipping on the input signal - didn't REW give a warning about that? It only shows the last measurement taken (was that with the 0dB volume?) so others may have been OK.


----------



## brucek (Apr 11, 2006)

> I did not turn off my mains because a 50hz crossover would limit these results.


I don't really understand that. If you shut off the mains and do a sweep to 200Hz with the sub only it will separate where problems lie between the mains or sub. Since the sub is the only device to receive equalization, it's the starting point. Do a sub only sweep and use logartithmic graphs (press the little ICON button at the top right hand side of REW called Freq Axis). 

Once you have equalized the sub, then add the mains and work on the crossover transition problems that may arise. That is likely the problem dip at ~60Hz in your plots. Adjust the sub phase control to reduce that peak. It is likely a result also of having the mains set to large. Usually small is a better choice.

As John says, you're clipping your signal into the soundcard. The results are not useful until you solve that level problem. 
Look at the SCOPE tab and you'll see the clipping after you've taken a measure. 
In the SCOPE tab, the smooth sweep is the output of the soundcard and the dark red envelope is the input to the soundcard with the Y axis is the percentage of digital full scale.

Here's a SCOPE of a normal sweep. See the dark red does not hit the light red.









If I expand the vertical scale I see a nice input waveform of input and output signal of REW.









Here is what it would look like with the signal clipped - not good.










In the impulse response the harmonic distortion components appear as additional impulses at negative time. You have a lot of distortion showing. Do a cable only loopback measure to see if your computer and soundcard are contributing to this problem.......

brucek


----------



## thewire (Jun 28, 2007)

brucek said:


> I don't really understand that. If you shut off the mains and do a sweep to 200Hz with the sub only it will separate where problems lie between the mains or sub. Since the sub is the only device to receive equalization, it's the starting point. Do a sub only sweep and use logartithmic graphs (press the little ICON button at the top right hand side of REW called Freq Axis).
> 
> Once you have equalized the sub, then add the mains and work on the crossover transition problems that may arise. That is likely the problem dip at ~60Hz in your plots. Adjust the sub phase control to reduce that peak. It is likely a result also of having the mains set to large. Usually small is a better choice.
> 
> ...


It seems then perhaps I would be better off giving my soundcard a try instead of USB. I thought the best idea was to get a basic understanding of how well a job my receiver is doing at equalization on it's own first before I make manual corrections. I could turn my volume down to like -50 and the clipping would stop. 



cnet said:


> Sporting the latest revision of Pioneer's autosetup program, MCACC (Multi-Channel Acoustic Calibration), the Pioneer VSX-72TXV balances the satellite speakers' volume levels, measures speaker-to-listener distances, determines the various sizes of the speakers, and equalizes the frequency response of the speakers in your room. This Advanced MCACC also applies "time axis" calibrations that distinguish between the direct sound of the speakers and the room reverberation to produce a more accurate sound. Using the MCACC system is quite simple. Just plug in the supplied microphone, place it at your main listening position, bring up the setup menu, and press the Enter button on the remote. A few minutes later, the Pioneer VSX-72TXV will be tuned to your speakers and room.


 One problem is that I have digital SPL meter as a mic and not the supplied one. Another problem is my amplifiers are so much more powerful than the internal amps (90w vs 125w) because I also use a bi-wiring and separates configuration to provide the best quality audio possible. It is over 400ft of wire hence the name I choose "thewire". It sets every volume level to -10db except the sub no matter what mic I have tried. The method it applies to my sub is "bass management" not equalization. This is adjustable using what is called Bass peak level.



cnet said:


> The next level of bass management came along in 1990 with the Lucasfilm THX standards, which required each speaker to produce 105dB of bass output at the listening position to match the film-studio experience. Realizing that a speaker capable of producing such a prodigious amount of bass would be impractical in all but the rarest of rooms, THX opted for a basic form of bass management to reduce the requirements for speakers. The bass from all the main channels was redirected to one or more subwoofers, allowing the speaker system to produce plenty of bass-kickage in the room with main speakers the size of most "bookshelf" speakers.
> 
> The final development of the full concept for bass management occurred when Dolby Digital and DTS discrete 5.1-channel digital formats were released to the consumer market circa 1995. Both formats included an additional channel, called LFE (Low Frequency Effects) dedicated to high-volume bass sound effects that required a playback system capable of producing 115dB of bass at the listening position. To optimize the reproduction of low frequencies for these new formats, bass management would include:
> 
> ...


You want me to use my soundcard? Should I use a less quality mic that will not pick up background noise or clip for my auto-setup? Should I buy the actual setup mic? Should I turn of my equalizer and test that way? I could do this the same as people are used to if needed. I will take a photo to better show what I am talking about and post it in a few minutes.


----------



## thewire (Jun 28, 2007)

The photo of my incorrectly setup system. Please help me use REW the right way. 











Edit: Please note that I have saved the faq page to my computer now for reference while I am using the program. Also note that I can not adjust my USB input volume. Please see my previous post for my questions. Also read my "notes" section. Thank you.


----------



## thewire (Jun 28, 2007)

JohnM said:


> The scope plot shows heavy clipping on the input signal - didn't REW give a warning about that? It only shows the last measurement taken (was that with the 0dB volume?) so others may have been OK.


Yes the db measurement was the clipping result for each setting. ta


----------



## brucek (Apr 11, 2006)

I don't really know if your Auto EQ system is correct or not. I assume it works fine. These auto eq systems usually target wide bandwidth corrections (and rightly so) and at frequencies usually above subwoofer problem areas. I see the lowest correction in your photos is 63Hz.

I'm not sure what you're trying to accomplish. The response graphs you have posted are fine other than a dip at 60Hz. As I said you could probably correct a lot of that with sub phase or a bit of sub distance setting.

REW is usually used to correct subwoofer resonance problems. It is used to measure subs and mains speakers (not surrounds or centers). Use it only with the receiver in stereo. It matters not what power your amplifiers are. You set the level at your listening position to 75dB and set REW up for 75dB targets.

brucek


----------



## Doug Plumb (Mar 16, 2007)

To check if your EQ is OK take a new set of measurements with slightly different mic locations and see if your EQ improves those.

I think EQ is best applied between about 100 Hz and 5 KHz. You can really improve the mid band response of almost any speaker if you know what you are doing.

The manual for RPlusD downloadable from the link explains this in the chapter on Practical Measurements.


----------



## thewire (Jun 28, 2007)

brucek said:


> I don't really know if your Auto EQ system is correct or not. I assume it works fine. These auto eq systems usually target wide bandwidth corrections (and rightly so) and at frequencies usually above subwoofer problem areas. I see the lowest correction in your photos is 63Hz.
> 
> I'm not sure what you're trying to accomplish. The response graphs you have posted are fine other than a dip at 60Hz. As I said you could probably correct a lot of that with sub phase or a bit of sub distance setting.
> 
> ...


I want to accomplish something in the range of my adjustments. -10 for every speaker is wrong. -10 is as low as it can be adjusted. That tells me it could be wrong for the equalizer I thought.

I want to use REW to know what is wrong.

So my auto-setup works? REW will do better than my db meter?

I posted the above because people are confused.


----------



## thewire (Jun 28, 2007)

Doug Plumb said:


> To check if your EQ is OK take a new set of measurements with slightly different mic locations and see if your EQ improves those.
> 
> I think EQ is best applied between about 100 Hz and 5 KHz. You can really improve the mid band response of almost any speaker if you know what you are doing.
> 
> The manual for RPlusD downloadable from the link explains this in the chapter on Practical Measurements.


Thank you. :hail:


----------



## Doug Plumb (Mar 16, 2007)

You are welcome


----------



## brucek (Apr 11, 2006)

> I think EQ is best applied between about 100 Hz and 5 KHz. You can really improve the mid band response of almost any speaker if you know what you are doing.


Equalization corrections in this area are extremely localized and so should only involve very low Q filtering. Most people agree that room treatment is the answer for the 100hz to 500Hz range. Wide filters (such as tone control) can help at higher frequencies.



> REW will do better than my db meter?


Oh for sure. Even though REW is mostly used for setting up parametric equalizers in the 20Hz to 100Hz range (where equalization is most effective), you can certainly take a response measurement up to ~5KHz with a Radio Shack meter. This will give you an idea if the auto eq system has done its job with its low Q filtering.

As far as the -10db levels that your auto eq system is providing - I simply have no idea. Sorry. I'm sure you can over-ride and set them back to zero....

brucek


----------



## Doug Plumb (Mar 16, 2007)

> Equalization corrections in this area are extremely localized and so should only involve very low Q filtering. Most people agree that room treatment is the answer for the 100hz to 500Hz range. Wide filters (such as tone control) can help at higher frequencies.



This is speaker EQing I am talking about and it can be done and the differences in many cases are obvious even for top end speakers.

At lower frequencies you can EQ out some sharp resonances such as I had at around 140 Hz, it gave the room an unusual sound be once that peak was smoothed out the sound really improved - in some measurements you can't see the peak and get a dip for applying the EQ but this is OK because sharp dips are barely audible.

EQing speakers can be done but for frequencies above about 1000 Hz. This is room independent.


----------



## thewire (Jun 28, 2007)

brucek-

Yes I can manually adjust settings like the speaker level without compromising others. Based on what I have been able to post do you think room treatments may be a good idea? 

Doug - 

I will give that program a demo sometime. Perhaps what I need is to input my mic into the computer and calibrate it to the correct volume using REW somehow and then output the mic input of my soundcard into the mic input of the receiver. Would this work? Would it harm my receiver?


----------



## JohnM (Apr 11, 2006)

thewire said:


> I could turn my volume down to like -50 and the clipping would stop.


Are you sure you are using a line input? That behaviour sounds more like what would happen with a mic input.


----------



## thewire (Jun 28, 2007)

JohnM said:


> Are you sure you are using a line input? That behaviour sounds more like what would happen with a mic input.


Line input??? No i used mic input.:hide:


----------



## brucek (Apr 11, 2006)

> Line input??? No i used mic input.


Mic inputs are not suitable. They have too much gain and are quite noisy. They also have a limited bandwidth. 

Take some time and read The REW Help Files. They are well written and are extremely helpful.

brucek


----------



## thewire (Jun 28, 2007)

brucek said:


> Mic inputs are not suitable. They have too much gain and are quite noisy. They also have a limited bandwidth.
> 
> Take some time and read The REW Help Files. They are well written and are extremely helpful.
> 
> brucek


Yes I had better read the whole thing.

I got a more correct looking and sounding setup when I output both the left and right using a Y cable from the spl meter into the receiver mic input.

instead of - speakers large sub volume = near 10db everything else -10db
db for channel volume or..

- speakers small sub volume -10db.

I get instead all speakers to large and the sub -10 which should be correct given the advanced bass management and equalizer.

I have a mono version do you think I should be using that instead? I'm not even sure however what this cord was intended for but it looks like a camera to rca (composite) cable and it has one of those bulky type ends on it before it becomes the headphone jack. My receiver has readings for both left and right outputs so I am not sure why this would compromise the mono signal but does that seem better than trying the mystery cable? Test tones on a THX setup disk are the same db amount as when I had setup my older receiver manually which leads me to think it may setup speakers less than -10db but not tell me on the OSD. Please let me know if that sounds wrong.

Now that I figured out the line input... 

I am doing them again because I would like to think about how I can improve areas next summer when we complete the theater, I want to see a measurement because it is what I set out to do ,and because it is fun. :jiggy:


----------



## thewire (Jun 28, 2007)

Just the front were set to small that was my error. I fixed that by turning the bass management for my sub off and setting the front to small. The crossover was correct at 80hz. I think the mic setup is correct. It says to me fix SPL however so I did. I calibrated the mains to 75db. The sub ended up at 79db after the expert advise to set the channel level to -5db with the bass management off for it. I set the sub itself to THX instead of variable volume adjustments. One more db than my own manual setup.:whistling:

I got a 100ft phone line so I can get better help online while in the theater. The one in the theater isn't installed yet. I have been doing some temporary room treatments but we are talking to the contractor in a couple weeks. More later. :yes:


----------



## thewire (Jun 28, 2007)

I will be doing the room treatments sometime but not right away since even DIY will put me over budget at the time being. I got it working correctly but I will be using the REW again when I have a even better understanding of the results and more time to carefully plan treatments.


----------



## thewire (Jun 28, 2007)

I'm ready for a new test. I will try and adjust my new bass traps and see how many dowel rods I need. I will have to empty the room of tools and things. The front bass traps I am looking at for now.


----------



## thewire (Jun 28, 2007)

Is it alright to post adjustments between 10HZ - 30HZ?


----------



## brucek (Apr 11, 2006)

You can post any graphs you like. We just _suggest_ that members post with a 15Hz-200hz and 45dB-105db to keep consistency for comparisons. Lot's of DIY subs extend to 10Hz quite nicely and you'll see those people using 10Hz as the starting point.

brucek


----------



## thewire (Jun 28, 2007)

brucek said:


> You can post any graphs you like. We just _suggest_ that members post with a 15Hz-200hz and 45dB-105db to keep consistency for comparisons. Lot's of DIY subs extend to 10Hz quite nicely and you'll see those people using 10Hz as the starting point.
> 
> brucek


Thank you. I have a DIY planned for the front of my room (pre wired) but that is in the design process. It isn't there yet but I need to document it during the building of my room. I will do 10HZ to 200HZ then.


----------



## thewire (Jun 28, 2007)

My sound card is not perfect and since the last test it now has a hum. Turning off my computer to rest did not fix it this time for some reason. Is it maybe because my card is loose? I checked all the connections to the computer and the receiver. Attached is my scope and a link to where the current results are which may need correcting. Does the scope look like I can continue testing? :sad:

recent photos


----------



## thewire (Jun 28, 2007)

This is a 12" sub in the rear of the room and the mic is in the center. The DIY sub will go in the front of the room.


----------



## brucek (Apr 11, 2006)

> Does the scope look like I can continue testing?


Yes.....

Temporarily use a ground lift cheater on your computer will tell if it's a ground loop.

brucek


----------



## thewire (Jun 28, 2007)

That's right I forgot that. I have one of those in the closet.


----------



## thewire (Jun 28, 2007)

My search on the help file doesn't work. I use Java 6. I will look to see where I read about this before. Attached is when I connect the line in and the line out with headphone jacks. :help:


----------



## thewire (Jun 28, 2007)

I will try moving my hard drives and the cd burner back the way they were before.


----------



## thewire (Jun 28, 2007)

The drives were ok. The heat sink looks decent. The cables are in good looking shape. The power supply doesn't sound so good and it might need replacing. I am not sure if I have any good power supplies left but I will take a look.


----------



## thewire (Jun 28, 2007)

I will try this other power supply the tester says it works. If that's not it I am not sure what to do. :dontknow:


----------



## thewire (Jun 28, 2007)

There is an electric leaf blower sharing the line with my lobby and the computer hooked up to it. When it's off it sounds better. I guess the front lawn is done. Everything is alright now sorry. :duh:


----------



## thewire (Jun 28, 2007)

Different results but the same conclusion. I also selected the better original result which was stereo mode. I was using my 7 channel one before as a comparison which was for an entirely different test not having to do with anything more than fixing a speaker and checking a sub enclosure. I might not have noticed sooner if I hadn't done the test over so it worked out for the better.











The blue is before any traps at all. I did test with different numbers of dowel rods positioned at both horizontal and vertical axis. This was done by laying them under the vertical piece or by laying the larger ones behind the smaller horizontal ones. The purple is the test of the new trap design. The test of different types was very small so that is not shown. The design I choose had the most overall smooth response. These got 1/3 octave smoothing. (see photo) 










Close up of testing the front bass traps. There is no GOM on any traps yet. The rear have no dowel rods and are loosely secured. (see photo)










The front bass traps during the first test. The dowel rod's need wood filler and the painting of the frames are almost done.

I think that is as close as I can get to proper testing. I am anxious to see what the MACC does now. These test are with it on but unchanged.


----------



## brucek (Apr 11, 2006)

You're really going to have to tell me what DOWEL RODS, GOM and MACC are before I can begin to appreciate what you're doing. :huh:

brucek


----------



## thewire (Jun 28, 2007)

Dowel rods are the wooden rods that I am using that go across the frame. They are held in place by friction because I bent them to fit in the holes I made. If you look carefully at the photo you can see how they are in there. Many designer bass traps have similar design. I modeled these after some ones I saw online that were THX. Gom is the fabric that goes across the front and acts like acoustical cloth. Midrange frequencies go inside the Guilford of Maine cloth and can't escape because of that gap. That makes it act like an absorber for the midrange as well. The dowel rods displace a certain amount of sound as well and add strength to them. The more strength to them the less the wall acts like a bass trap. I began seeing these "decorative" designs online when they were fairly new. I just copied what they looked like and made it out the DIY materials. The fabric I will tuck in between the wall and the frame which is the furring strips. Those might have a correct term but I call them a frame for now. MACC is the equalizer on my receiver that uses a microphone and then does an auto setup of the equalizer on it's own that was made by Air Studious. I have to manually turn of the bass management and adjust volumes using an SPL meter but it takes care of everything else. My next receiver or preamp well also have an equalizer.


----------



## thewire (Jun 28, 2007)

I'm not a pro so if anyone can help out it is appreciated.


----------



## thewire (Jun 28, 2007)

I made a mistake on the MACC term. That is a college I went to. The equalizer is MCACC. 

The bass traps I think I have nailed (as an expression) now. I picked up more supplies because I had forgotten I had two layers of GOM. I can't fit to layers in like I wanted before and even one may have been to difficult or not looked good so it is on to plan B. I will staple them to the sides folded inward with the staple gun, then I will cover the sides with a thin trim that I will try hot gluing. If the hot glue doesn't work I will use black paneling nails that I will touch up with paint. I am spray painting the trim flat black. I also picked up the extra crown molding and I will get the miter saw tomorrow. I am looking forward to another test since I have attached the rear bass traps to the walls better.


----------



## thxgoon (Feb 23, 2007)

I'm not sure if you've figured out your -10 speaker levels setting problems but it could be related to the fact that you are not using the provided mic from pioneer. The MCACC program is calibrated to work with that mic, so using something else will likely provide erroneous results. That or the gains on your external amps are really high. Also, who's expert advice told you to set your sub -5 from the mains? If it sounds good then great but there is no locked in stone rule for setting the level of your sub. I'd look ad REW and adjust from there.


----------



## thewire (Jun 28, 2007)

thxgoon said:


> I'm not sure if you've figured out your -10 speaker levels setting problems but it could be related to the fact that you are not using the provided mic from pioneer. he MCACC program is calibrated to work with that mic, so using something else will likely provide erroneous results. That or the gains on your external amps are really high.


In the years I have had my receiver nobody has ever suggested to me to get a mic before. My external amps are likely the problem because I had to turn my receiver down the same with my last one. 



thxgoon said:


> Also, who's expert advice told you to set your sub -5 from the mains? If it sounds good then great but there is no locked in stone rule for setting the level of your sub. I'd look ad REW and adjust from there.


I read this at another forum. It was not an expert just someone telling me what an expert told them.



Highside said:


> Here's what I've learned from a true expert in the field of "bass management". I would go into more detail but the theories should be address in the Subwoofer section of the forum first and then the audio forum.
> 
> In a nutshell: If you have a Subwoofer.....
> 
> ...


My sub is running hot in both setups intentionally but I will calibrate it with REW for the THX setting on the back of my sub later yes. In the test it is set to max. I have not tried the SPL meter files yet also. My test are not intended for equalization yet just to see what is going on because I have never been a home theater with room treatments before and I want to learn what is going on. Alot of people like their subs hot so I am keeping an eye on that. Sorry I forgot to mention that here.


----------



## thewire (Jun 28, 2007)

My setting turned out to be -2 not -5 I think for the AVR sub volume. The test was done after my own adjustments and if the sub was at THX setting it would have been close but I still had it +2 or +3 hot. It is in my post somewhere when the testing started.


----------



## clubfoot (Apr 12, 2007)

thewire said:


> My setting turned out to be -2 not -5 I think for the AVR sub volume. The test was done after my own adjustments and if the sub was at THX setting it would have been close but I still had it +2 or +3 hot. It is in my post somewhere when the testing started.


I hope you're performing all your tests with bass peak-level limiter off and room boundary gain off, otherwise,...


----------



## thewire (Jun 28, 2007)

clubfoot said:


> I hope you're performing all your tests with bass peak-level limiter off and room boundary gain off, otherwise,...


 I think I am alright there. I set my bass peak-level to 0. I do not have a room boundary gain setting that I am aware of. I don't have a manual to the VSX-1012. I used a manual from a different model number that is the same thing which is the 45TX and I don't remember that one.


----------



## thewire (Jun 28, 2007)

If my bass-peak level setting goes higher than 0 does that mean it is not off? It also goes to +12.


----------



## thxgoon (Feb 23, 2007)

You should be able to set the bass peak limiter 'off'. 

The only 'expert' in calibrating _your_ subwoofer level in _your_ system is _your_ ears.

Also, to my knowledge all MCACC receivers come with a mic. Different mics have different frequency responses, sensitivities etc.. just like any speaker does. If the system software does not know how the mic will react it has absolutely no way of knowing what is really going on in your room. It is imperative to use the included mic IMO. It's the same reason that members of this forum have gone to such great lengths to get calibration files for the spl meters we all use. They are not perfect and don't spit out accurate numbers. So we measure the response of the meters so we know exactly what is going on in our rooms.


----------



## clubfoot (Apr 12, 2007)

thewire said:


> If my bass-peak level setting goes higher than 0 does that mean it is not off? It also goes to +12.


On my Integra once the level is increased past zero/off it produces an LFE signal and it is adjusted until you do not hear audible distortion or bottoming.


----------



## thewire (Jun 28, 2007)

here is with the bass peak level at +12. Tell me if I have been wasting my time. I'm all ready now. :sarcastic:



deleted photo


----------



## thewire (Jun 28, 2007)

clubfoot said:


> On my Integra once the level is increased past zero/off it produces an LFE signal and it is adjusted until you do not hear audible distortion or bottoming.


 I see thank you that does help allot.


----------



## thewire (Jun 28, 2007)

My computer desk is sitting directly in front of a bass trap (has been) and there are tons of things in here for that test above also btw.

Edit: deleted my room test result.


----------



## thewire (Jun 28, 2007)

I will order a mic from pioneer but I am not sure it is worth it since the receiver is being replaced for a HDMI 1.3 anyway. I will see if we need the equalizer for where this receiver ends up. I am not sure how it would help on the dock.  

If I remember correctly they are about 20 dollars. It is worth it I think for now until May. Do you think that is worth it?


----------



## thewire (Jun 28, 2007)

I had forgotten there is 24 and Lost TV seasons on DVD coming out. The mic will be ordered with no doubt. Thank you thxgoon.


----------



## thxgoon (Feb 23, 2007)

Sure. Do you have any graphs of your room response to 20khz? I'd take a look at that and see how things look. To be honest if you're going to upgrading again soon and things sound good, I'd say do your best to set levels manually and use REW to see how close you are getting to a flat response. It may be that things would be fine until you upgrade, but using Pioneer's mic would be best.


----------



## thewire (Jun 28, 2007)

thxgoon said:


> Sure. Do you have any graphs of your room response to 20khz? I'd take a look at that and see how things look. To be honest if you're going to upgrading again soon and things sound good, I'd say do your best to set levels manually and use REW to see how close you are getting to a flat response. It may be that things would be fine until you upgrade, but using Pioneer's mic would be best.


I have every test saved. :bigsmile: It can be confusing so I try to use the notes box as most often as I can. I have all the GOM attached to the frames and I am painting the trim. This is what I see so far from the other day.


----------



## thewire (Jun 28, 2007)

brucek said:


> Tremendous amount of noise in your impulse response. What does the impulse response look like when you measure a simple loopback cable? This will tell us if the computer is capable of a proper reading.
> 
> Always set the graphs to logarithmic - not linear.
> 
> ...


I will do so from now on. It was kind of difficult to figure out how. My search in the help file did not work. It was not obvious what the setting was. I read about Logarithmic in my new book.

Why the recommendation about stereo mode I am still unclear about that


----------



## thewire (Jun 28, 2007)

My noise is still in the impulse response. Would that be computer hardware related still since I have switched from using the mic input to the line in input


----------



## brucek (Apr 11, 2006)

> Why the recommendation about stereo mode I am still unclear about that


Stereo mode enables only the front two mains speakers and usually with no soundfield turned on. You don't want a bunch of DSP effects upsetting the measurements..



> My noise is still in the impulse response


Ensure the input levels are set correctly and use multiple long sweeps feature...

brucek


----------



## thewire (Jun 28, 2007)

I will wait until I have a computer with no hum from the line out before I ask for any more help.


----------

