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My equalization/room look ok?

6K views 62 replies 6 participants last post by  thewire 
#1 ·
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:
 
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#30 ·
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.
 
#31 ·
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
 

Attachments

#40 ·
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.
 
#42 ·
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.
 
#44 ·
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.
 
#45 ·
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.
 
#46 ·
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.

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.....

1.Set all of your speakers to small. Why? If your sub is up to task (i.e. sized properly for your room emvironment) it WILL do all of the needed work. 80hz is a great crossover point where even large speakers will benefit. No need to send the lower stuff to them as your sub will easily take up the slack.

2.Make sure your LFE channel in your AVR is set to "Sub Only or Sub On". You don't want any re-directed bass going to your mains. Once again, let the sub do the work.

3.Make sure the Subwoofer trim (volume) is set in the low to middle setting on your AVR. This function controls the volume your sub (not LFE) outputs through your AVR. This can be adjusted later after the volume knob on the sub is set to where you like. Then if you want a tad more bass, raise the Sub trim in your AVR.

4.Make sure the LFE trim (different function than Subwoofer trim) is set to max. Most AVRs have a -20 to 0 db range. Set the DD LFE and the DTS LFE to 0. this will give an unaltered signal from your AVR.

5.All levels absolutley need to be set with an SPL meter. You will NEVER get close without it.

Here's a quick exerpt from another website that I can't find but it's a very simple setup proceedure.

In your AVR:

All speakers set to small.
Crossover set to 80 Hz.
Subwoofer set to on/yes.
"LFE + Mains" or any other channel remix options set to off/no.
Dolby Dynamic Range Compression (DRC) aka Midnight Mode circuit set to off/no.
LFE Channel (the ".1" in 5.1) is enabled (Pioneer MCACC). This is not the subwoofer channel.
LFE channel level is set to maximum (i.e., unattenuated) value.
THX (or any other) bass limiter circuit set to off/no.
Subwoofer pre-out level to -5 (on a scale of -10 to +10).
THX Ultra 2 Boundary Gain Compensation is set to off/no.
Standing Wave (Pioneer Advanced MCACC) feature is set to off/no.

On your sub:

All ports open (if sub is variable tune) — you can retune lower later-on if needed.
Match tune switch to port configuration (if sub is variable tune).
Set low pass filter switch to "disable".
Set the phase control to 0 degrees.

A ton more can be learned in the Sub section of the forum which I would highly recommend.

Rob
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.
 
#47 ·
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.
 
#48 ·
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,...
 
#49 ·
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.
 
#51 ·
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.
 
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