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Did you measure your sub with measurement gear ?????? - Page 2

Poll Results: Did you use measurement gear to setup your subwoofer

 
  • 80% (40)
    Yes
  • 20% (10)
    No
50 Total Votes  
post #31 of 81
Updates? Sorry, at this time and point, nothing really worth mentioning.

So far, I've recently purchased a DSPeaker, Anti-Mode, 8033S II and installed it in the subwoofer information stream and rerun Audyssey MultEQ XT. Balanced everything with a digital sound meter.

At this time and point, I've finished putting the recording gear together with necessary patch cords to run from the office to the living room; 35'. I'm still attached to my desktop PC. Everybody else in the family has laptops but I'm hung up on the versatility of a desktop box.

Time has been spent learning about available real time room analyzing (RTA) software programs.

Time has been spent downloading and understanding TrueRTA and REW.

Time has been spent calibrating the phantom power supply to obtain the best loop signal.

The last is to find the time to run some calibrated sweeps in the living room.

That's where I'm at, getting ready to do frequency sweeps to see what's what with all the what.

rolleyes.gif

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Edited by BeeMan458 - 12/18/12 at 5:10am
post #32 of 81
Currently running REW using the AVR provided rumble mode.

I don's seem to be able to get a test tone to play from REW to the AVR. I'm sure that's simply a misunderstanding on my part how to set the input settings.

Using the AVR provided test tone, I'm able to easily see the room's acoustics and at first blush, the dB/Frequency graph is a dB trough over 20 - 200 Hz.

Both 20hz and 200Hz are identical and from 20Hz, slowly drops 7dB to the middle (55hz to 100Hz) and then equally rises slowly on the other end of the graph to 200Hz.

My personal concern is the part of the graph associated with the LFE channel information, 20 Hz > 120Hz.

There seems to be a problem getting REW to play and get along well with the AVR's output. That or I'm getting run over by the learning curve. tongue.gif

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Edited by BeeMan458 - 12/18/12 at 11:07am
post #33 of 81
Quote:
Originally Posted by BeeMan458 View Post

Currently running REW using the AVR provided rumble mode.

I don's seem to be able to get a test tone to play from REW to the AVR. I'm sure that's simply a misunderstanding on my part how to set the input settings.

Using the AVR provided test tone, I'm able to easily see the room's acoustics and at first blush, the dB/Frequency graph is a dB trough over 20 - 200 Hz.

Both 20hz and 200Hz are identical and from 20Hz, slowly drops 7dB to the middle (55hz to 100Hz) and then equally rises slowly on the other end of the graph to 200Hz.

My personal concern is the part of the graph associated with the LFE channel information, 20 Hz > 120Hz.

There seems to be a problem getting REW to play and get along well with the AVR's output. That or I'm getting run over by the learning curve. tongue.gif

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Off the top of my head, double check your inputs and outputs,also make sure your avr is set to the right signal.
post #34 of 81
Quote:
Originally Posted by sputter1 View Post

Off the top of my head, double check your inputs and outputs,also make sure your avr is set to the right signal.

Thanks. Went through the AVR pdf manual and can find the image which points and says, plug it in here but I can't find how to activate the input channel. I even switched to analogue and auto detect.....nada.

I verified the microphone was working by plugging into the line out on the phantom amplifier but I had a live graph, even when the microphone, phantom amplifier gain knob was turned to zero.

The RTA graph responded to changes in 25Hz and 35Hz boosts and when set to pass through (no Anti-Mode correction) but when the gain in the AVR's main menu was turned up, the dB scale of the RTA graph didn't go up, even though a noticeable increase in subwoofer volume.

Well, the short of the long story, we went out and took care of errands. Came home, had lunch and now the wife has taken over the living room and I've been relegated to the office. So, the issue will be revisited tomorrow. I'm sure you're correct as to setting the right AVR signal channel. I hate pdf and online manuals. I do much better with print manuals but I'm not going print out a hundred and thirty pages of manual. Manufactures should include printed manuals but noooooo, it's now, include a CD, charge the same and let the consumer deal with printing the manual.

Grrrrrrrrrrr.........mad.gif

Oh well. That's what tomorrow is for.

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Edited by BeeMan458 - 12/18/12 at 6:38pm
post #35 of 81
Quote:
Originally Posted by sputter1 View Post

Off the top of my head, double check your inputs and outputs,also make sure your avr is set to the right signal.

Roger on your above. biggrin.gif

Okay. Thinking back on my reading of REW directions, in the back of my mind I remember a comment stating that REW likes the right input. So I changed the microphone input from the left to the right input and everything came on line. Yeah baby!

Based on manufactured specs the sub is spec'd for 28Hz > 120Hz frequency range. Reading 25Hz to 105Hz, the graph is flat, +/-5dB. There's a very noticable roll off after 105Hz.

Below is a reading of both A and B subs playing simultaneously.



(Anti-Mode- no boost filters engaged and Audyssey MultEQ XT engaged)

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Edited by BeeMan458 - 12/19/12 at 12:16pm
post #36 of 81
Quote:
Originally Posted by BeeMan458 View Post

Quote:
Originally Posted by sputter1 View Post

Off the top of my head, double check your inputs and outputs,also make sure your avr is set to the right signal.

Roger on your above. biggrin.gif

Okay. Thinking back on my reading of REW directions, in the back of my mind I remember a comment stating that REW likes the right input. So I changed the microphone input from the left to the right input and everything came on line. Yeah baby!

Based on manufactured specs the sub is spec'd for 28Hz > 120Hz frequency range. Reading 25Hz to 105Hz, the graph is flat, +/-5dB. There's a very noticable roll off after 105Hz.

Below is a reading of both A and B subs playing simultaneously.



(Anti-Mode- no boost filters engaged and Audyssey MultEQ XT engaged)

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A couple things.
Your graph is eq'ed via audyssey?
Crank up the volume to 85db and see what you get, that's a pretty low sweep.
Change the graph to read in 5dbs rather 10dbs
post #37 of 81
Quote:
Originally Posted by sputter1 View Post

A couple things.
Your graph is eq'ed via audyssey?

The graph is EQ'd with both Audyssey MultEQ XT and DSPeaker, Anti-Mode, 8033S II in the information stream.

Quote:
Crank up the volume to 85db and see what you get, that's a pretty low sweep.

Sure. I'm using the AVR provided test tone to the subwoofer channel and the setting used for movie watching. When the wife leaves the living room, I'll crank up the AVR gain to a SPL of 85dB.

Quote:
Change the graph to read in 5dbs rather 10dbs

Done. Here's 5dB graph. When the wife frees up the living room, I'll do some 85dB.readings. The peak is 62.64dB and the null is 55.98 dB with a roll off issue from 105Hz > 120Hz.


Edited by BeeMan458 - 12/19/12 at 1:01pm
post #38 of 81
Quote:
Originally Posted by BeeMan458 View Post

The graph is EQ'd with both Audyssey MultEQ XT and DSPeaker, Anti-Mode, 8033S II in the information stream.
Sure. I'm using the AVR provided test tone to the subwoofer channel and the setting used for movie watching. When the wife leaves the living room, I'll crank up the AVR gain to a SPL of 85dB.
Done. Here's 5dB graph. When the wife frees up the living room, I'll do some 85dB.readings. The peak is 62.64dB and the null is 55.98 dB with a roll off issue from 105Hz > 120Hz.

You are +/- 3.5 dBs from 25-105 hz.
post #39 of 81
Quote:
Originally Posted by BeeMan458 View Post

The graph is EQ'd with both Audyssey MultEQ XT and DSPeaker, Anti-Mode, 8033S II in the information stream.
Sure. I'm using the AVR provided test tone to the subwoofer channel and the setting used for movie watching. When the wife leaves the living room, I'll crank up the AVR gain to a SPL of 85dB.
Done. Here's 5dB graph. When the wife frees up the living room, I'll do some 85dB.readings. The peak is 62.64dB and the null is 55.98 dB with a roll off issue from 105Hz > 120Hz.

Perhaps I am wrong, but I thought you needed to use the REW generated test tones when using the software?
post #40 of 81
Quote:
Originally Posted by ack_bk View Post

Quote:
Originally Posted by BeeMan458 View Post

The graph is EQ'd with both Audyssey MultEQ XT and DSPeaker, Anti-Mode, 8033S II in the information stream.
Sure. I'm using the AVR provided test tone to the subwoofer channel and the setting used for movie watching. When the wife leaves the living room, I'll crank up the AVR gain to a SPL of 85dB.
Done. Here's 5dB graph. When the wife frees up the living room, I'll do some 85dB.readings. The peak is 62.64dB and the null is 55.98 dB with a roll off issue from 105Hz > 120Hz.

Perhaps I am wrong, but I thought you needed to use the REW generated test tones when using the software?

You do but you can set your measurment lvls 75db, 81.5db.. etc
post #41 of 81
If Audyssey counts then yes. I do not have the knowledge yet or the equipment to run my own sweeps. Hope to get into that in the near future.
post #42 of 81
Quote:
Originally Posted by Smigro View Post

If Audyssey counts then yes. I do not have the knowledge yet or the equipment to run my own sweeps.

The good news, with Audyssey there's hope.

Quote:
Hope to get into that in the near future.

No you don't. Be warned. By acquiring measuring gear, one enters a whole new level of personal frustration as now you're trying to beat the tape........and nobody beats the tape. tongue.gif

As to taking readings of a room, the RTA reads the room's acoustics, not only calibrated sweeps. A sweep is a known standard but a RTA program doesn't care. As an example, the RTA will read and graph the sound of someone waking across the listening room floor if the operator so chooses.
post #43 of 81
Here's a graph of today's efforts.

For comparison, using a 5dB graph, first graph captured yesterday.



Today's capture.




Minus the little modal at 45Hz, the graph is +/-3.6dB, 23dB > 121dB.

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Edited by BeeMan458 - 12/20/12 at 2:53pm
post #44 of 81

Something still doesn't seem right, those levels still seem too low and I would think may be impacted by your noise floor.  And the curves just seem to "rigid" for the lack of a better term.  Assuming you are using the REW frequency sweeps?

post #45 of 81
Quote:
Originally Posted by primetimeguy View Post

Assuming you are using the REW frequency sweeps?

I'm using the AVR provided subwoofer test tone. The test tone was playing at or about 75dB, verified by a Radio Shack, digital sound meter. The system was calibrated (lowest distortion) with REW before the test graphs were made.

Not sure what you mean by rigid. What you're seeing, might have to do with how I set REW up as I set preferences to "Averages - 32." By doing it this way, graph movement is slowed down so I can interpret what I'm seeing on screen by slowing things down. Doing so, IMO, give an accurate representative snapshot of what is being seen on the realtime screen. And yes, there's always room in my thinking that I may have things screwed up.

I'm still having to play-n-learn so as to better understand the interaction between Anti-Mode, Anti-Mode's boosters/filters and REW's interaction with the recording appliances.

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Edited by BeeMan458 - 12/20/12 at 3:30pm
post #46 of 81

You can't use the receiver test tone to measure frequency response in REW, you need to use the REW generated frequency sweeps.  So unfortunately I don't think those graphs are telling you much of anything at this point.

 

Noting that you are playing a 75db tone but only measuring about 60db shows something is amiss.

 

When you press the Measure button in REW it should output a freq sweep to your receiver and then measure that response.  


Edited by primetimeguy - 12/20/12 at 4:07pm
post #47 of 81
If you were measuring at 75db then rew would reflect that. You're doing something wrong somewhere.
post #48 of 81
Quote:
Originally Posted by sputter1 View Post

If you were measuring at 75db then rew would reflect that. You're doing something wrong somewhere.

No argument. I don't know the how or why of the graph but the SPL meter on REW showed the correct SPL as calibrated by a hand held sound meter and then the numbers were entered into and corrected for in REW.
post #49 of 81
Quote:
Originally Posted by primetimeguy View Post

Noting that you are playing a 75db tone but only measuring about 60db shows something is amiss.

What's amiss is, I can't get the signal to the AVR to play sweeps through the speakers. I'm all cabled and ready to go but I can't figure out how to switch the input choice to the front panel of a Marantz, SR5007. Sorry guys, in this case, I've gone all Homer Simpson on ya'll. D'oh!

I can raise the test tone and see the raise. I can change the phase and see how the phase change has changed the plot of the graph so right or wrong, in my thinking, I figure continuous noise is noise and by setting the responsiveness of REW to "Averages 32," I'm getting a useable graph that shows me what's happening with the room in realtime.
post #50 of 81
Quote:
Originally Posted by BeeMan458 View Post

Quote:
Originally Posted by sputter1 View Post

If you were measuring at 75db then rew would reflect that. You're doing something wrong somewhere.

No argument. I don't know the how or why of the graph but the SPL meter on REW showed the correct SPL as calibrated by a hand held sound meter and then the numbers were entered into and corrected for in REW.

You did the loopback and saved/loaded your cal file?
You ran the "check level"? you use your spl meter beside your mic and turn up your avr to get the spl level you want.
How about the mic/spl cal file?
post #51 of 81
Quote:
Originally Posted by sputter1 View Post

You did the loopback and saved/loaded your cal file?
You ran the "check level"? you use your spl meter beside your mic and turn up your avr to get the spl level you want.
How about the mic/spl cal file?

Roger all the above.

First thing I did was calibrate the phantom power supply, as you suggested, using the loop back function. File was saved and shows onscreen as being available to REW.

I downloaded the microphone calibration file and the file is showing as a choice that's available to REW.

Not knowing anything about anything in this case, the microphone readings are showing they're responsive to the changing environment. If I change the phase knob, ten percent, I can see the changes to the room's acoustics so I'm comfortable with what I'm seeing live on the screen. If I'm wrong about this, then I'm wrong so I'm not trying to say it's not possible for me to be in error. The neat thing about a RTA is, it listens to a room and takes what the microphone picks up and throws it on the screen. I had a lot of fun dialing in the phase difference of the two subs and immediately would see the affect a small change in phase would have on the overall room acoustics.

It was quite interesting to see the screen change as the Anti-Mode when through it's calibration algorithms. A test tone sweep would play and on the screen, you can see the progression as each 5dB or 10dB filter was tried out. The viewer can also see how the Anti-Mode tires to set everything to an 80dB standard until 175Hz where it then attenuates as the test progresses. And then the sweep starts again as Anti-Mode goes through, I think, seven iterations. Sometimes it uses five dB increments and other times it uses 10dB increments. Sometimes it uses five and ten step increases in dB and other sweeps it uses offset frequency choices. It's just neat stuff to see the test sweep progression taking place, right before your eyes, as opposed to using your ears. Very exciting stuff.
post #52 of 81
Quote:
Originally Posted by BeeMan458 View Post

Quote:
Originally Posted by sputter1 View Post

You did the loopback and saved/loaded your cal file?
You ran the "check level"? you use your spl meter beside your mic and turn up your avr to get the spl level you want.
How about the mic/spl cal file?

Roger all the above.

First thing I did was calibrate the phantom power supply, as you suggested, using the loop back function. File was saved and shows onscreen as being available to REW.

I downloaded the microphone calibration file and the file is showing as a choice that's available to REW.

Not knowing anything about anything in this case, the microphone readings are showing they're responsive to the changing environment. If I change the phase knob, ten percent, I can see the changes to the room's acoustics so I'm comfortable with what I'm seeing live on the screen. If I'm wrong about this, then I'm wrong so I'm not trying to say it's not possible for me to be in error. The neat thing about a RTA is, it listens to a room and takes what the microphone picks up and throws it on the screen. I had a lot of fun dialing in the phase difference of the two subs and immediately would see the affect a small change in phase would have on the overall room acoustics.

It was quite interesting to see the screen change as the Anti-Mode when through it's calibration algorithms. A test tone sweep would play and on the screen, you can see the progression as each 5dB or 10dB filter was tried out. The viewer can also see how the Anti-Mode tires to set everything to an 80dB standard until 175Hz where it then attenuates as the test progresses. And then the sweep starts again as Anti-Mode goes through, I think, seven iterations. Sometimes it uses five dB increments and other times it uses 10dB increments. Sometimes it uses five and ten step increases in dB and other sweeps it uses offset frequency choices. It's just neat stuff to see the test sweep progression taking place, right before your eyes, as opposed to using your ears. Very exciting stuff.

It is interesting to see.wink.gif

Try this then, post a measurement of 85db and 95db as measured by your meter.
post #53 of 81
Quote:
Originally Posted by sputter1 View Post

It is interesting to see.wink.gif
Try this then, post a measurement of 85db and 95db as measured by your meter.

Not upset but it does get real loud at a level of 85dB and 95dB. Our son is asleep during the day, the wife is on the computer in the next room over and the parrot is caged in the kitchen and starts stressing with loud noises as all rooms are attached by walls to the living room where our Home Theater system is located.

What benefit is there to be had by cranking the gain to a measured 85dB and 95dB as opposed to a measured 75dB?

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Edited by BeeMan458 - 12/20/12 at 7:00pm
post #54 of 81
Quote:
Originally Posted by BeeMan458 View Post

Quote:
Originally Posted by sputter1 View Post

It is interesting to see.wink.gif
Try this then, post a measurement of 85db and 95db as measured by your meter.

Not upset but it does get real loud at a level of 85dB and 95dB. Our son is asleep during the day, the wife is on the computer in the next room over and the parrot is caged in the kitchen and starts stressing with loud noises as all rooms are attached by walls to the living room where our Home Theater system is located.

What benefit is there to be had by cranking the gain to a measured 85dB and 95dB as opposed to a measured 75dB?

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To be sure you're not just measuring ambiant noise. Something is wrong and you need to have the basics right before you can determine your room. imho
post #55 of 81
Quote:
Originally Posted by sputter1 View Post

To be sure you're not just measuring ambiant noise. Something is wrong and you need to have the basics right before you can determine your room. imho
+1. This morning I needed to measure the level of the sound of a pair of scissors snipping. I went into a quiet room in my basement, turned on my handheld RTA, and there was a constant 65dB reading centered around 30Hz. I couldn't hear it, but the meter could. I knew from prior experience that it was traffic noise from a highway a half mile away, ground conducted to my basement. I filtered it out by switching the weighting from flat to 'A'. When you're taking measurements in room you have to do it at least at normal listening levels, preferably a bit higher, so that the measurement isn't corrupted by ambient noise, especially in the low frequencies that are hard to hear.
post #56 of 81
Were you measuring that so that you could cancel out the sound and get a silent haircut?tongue.gif
post #57 of 81
Quote:
Originally Posted by sputter1 View Post

To be sure you're not just measuring ambiant noise. Something is wrong and you need to have the basics right before you can determine your room. imho

Ambient noise level in the living room is around 53dB. When the test tone is shut off, the sound level fall accordingly to normal ambient noise levels.

I'm not sure what you mean by wrong. What do you think is wrong?

Fans are off. Room is hand measured. REM is calibrated to the hand held meter. REM's SPL meter is working and responds as I change the gain setting.

Wish I knew what was concerning you so I could make you feel comfortable or change to correct.
post #58 of 81
Quote:
Originally Posted by Bond 007 View Post

Were you measuring that so that you could cancel out the sound and get a silent haircut?tongue.gif

No silent haircut......I'm shaved bald. tongue.gif
post #59 of 81
Quote:
Originally Posted by BeeMan458 View Post

Quote:
Originally Posted by sputter1 View Post

To be sure you're not just measuring ambiant noise. Something is wrong and you need to have the basics right before you can determine your room. imho

Ambient noise level in the living room is around 53dB. When the test tone is shut off, the sound level fall accordingly to normal ambient noise levels.

I'm not sure what you mean by wrong. What do you think is wrong?

Fans are off. Room is hand measured. REM is calibrated to the hand held meter. REM's SPL meter is working and responds as I change the gain setting.

Wish I knew what was concerning you so I could make you feel comfortable or change to correct.

It's not to make me comfortable wink.gif I'm just trying to help you get it right. You said you're at 75db and i'm saying you're about 15db lower than you think according to REW.
At the level that REW is showing you need to measure at a higher level to help remove the noise floor reinforcement from your graph.

Other than that it makes no difference to me man, carry on. smile.gif
post #60 of 81
Quote:
Originally Posted by BeeMan458 View Post

Ambient noise level in the living room is around 53dB. When the test tone is shut off, the sound level fall accordingly to normal ambient noise levels.
I'm not sure what you mean by wrong. What do you think is wrong?
Fans are off. Room is hand measured. REM is calibrated to the hand held meter. REM's SPL meter is working and responds as I change the gain setting.
Wish I knew what was concerning you so I could make you feel comfortable or change to correct.

maybe you could try cutting a hole in the wall?
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