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Discussion Starter · #1 ·
Hi All:


I've been trying to measure the frequency response of my home theater using ETF5 acoustic software. My HTPC has an M-Audio Audiophile 2496 sound card. After a struggle I was finally successful in getting the sound card to talk to the software, but now the software is giving me unrealistic results (a 55dB dip in response).


Its possible that I may have incorrectly setup the soundcard software settings.


If you have successfully used ETF5 with an M-Audio Audiophile 2496 sound card, would you please tell me the Monitor Mixer and Patchboard/Router settings you are using?


Any other tips you might have regarding getting the software to work would be greatly appreciated.


Thanks in advance.


Larry
 

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Discussion Starter · #3 ·
Serge:


Welcome aboard, misery loves company.;)


I just bought the ETF5 acoustic software to use as a Real-Time acoustic analyzer so I can "intelligently" set the sliders on a multi-channel equalizer.


If you've got the time and are curious, you might be interested in wading through this active thread chronicling my "pain and suffering". :rolleyes:

Averaging Listening Positions when doing multi-channel equalization.


Larry
 

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Discussion Starter · #4 ·
Bump.


Serge:


Are you planning on using an Audiophile 2496 with ETF5?


If so, after you get started post your progress here and we can compare notes.


Thanks.


Larry
 

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I have a Delta 410 so it may be slightly different, but I didn't have any problem using ETF to measure and EQ my sub with a BFD. The hookup method was a bit different from what some of instructions for using a typical soundcard are. For instance, I didn't need any of those y-adapters.


In the Sounds and Audio Devices applet in Control panel, I set the default device for Playback and Recording to the analog inputs/outputs (ie M Audio Delta 410 1/2). Then I connected the left input to the left output using an RCA cable. I used another RCA cable to to connect the output of the RatShack SPL meter to the right input, and finally connected the right output on the Delta to the BFD's input using an RCA->Phone adapter. If you have a specific questions, feel free to ask.
 

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Larry:


I've successfully used a M-Audio Delta 410 card with ETF 5 to EQ my sub with a Behringer Feedback Destroyer, so I know it can be done. But since I'm at work, I can't recall the soundcard settings I used. I do remember having to dial down the gain in the Windows mixer to prevent overload. I used a Radio Shack SPL meter for a microphone and was concentrating mostly on eliminating bass nulls. I know that the software was working correctly, because it detected a serious null at about 40 Hz, which is precisely where the math would predict it to be in my rectangular room.


I'll try to review the steps I followed when I get home tonight.


- Ken
 

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Discussion Starter · #7 ·
Quote:
Originally posted by JKohn
I have a Delta 410 so it may be slightly different, but I didn't have any problem using ETF to measure and EQ my sub with a BFD. The hookup method was a bit different from what some of instructions for using a typical soundcard are. For instance, I didn't need any of those y-adapters.


In the Sounds and Audio Devices applet in Control panel, I set the default device for Playback and Recording to the analog inputs/outputs (ie M Audio Delta 410 1/2). Then I connected the left input to the left output using an RCA cable. I used another RCA cable to to connect the output of the RatShack SPL meter to the right input, and finally connected the right output on the Delta to the BFD's input using an RCA->Phone adapter. If you have a specific questions, feel free to ask.
John:


Thanks for the response.


The Audiophile 2496 has an M-Audio Delta Control Panel application that presents the user with 5-tabs each corresponding to a separate page of information. The two pages that I am particularly interested in are the Monitor Mixer and the Patchbay/Router. I assume the 410 has a similar control panel.


Could you please describe the setting that you are using on those pages? Perhaps you could attach screen shots of the pages?


John and Ken:


As a side issue were you confident that the Radio Shack meter was providing accurate results particlularly at low frequencies? Did you use a "correction" file. The file provided by Acoustisoft only goes down to about 600Hz. What did you do to get good measurements below 600Hz? My concern is not that ETF5 won't be able to show the peaks and valleys at the correct frequencies, but rather the size of those peaks and valleys might not be accurate. If the levels are not correct then when equalization is applied to flatten the frequency response, although it may look flat it may not actually be flat.


Did either of you later go back and use a more accurate microphone?


Thanks for your help.


Larry
 

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Quote:
The Audiophile 2496 has an M-Audio Delta Control Panel application that presents the user with 5-tabs each corresponding to a separate page of information. The two pages that I am particularly interested in are the Monitor Mixer and the Patchbay/Router. I assume the 410 has a similar control panel.
I'll double check tomorrow, but I'm 99% sure I left that stuff alone. The only thing I changed was the default source in the "Sounds and Audio Devices" Control Panel applet, as mentioned above.


About the SPL meter and a correction file for low frequencies. I have a correction file I got from one of the threads at HTF, and I'm attaching it here. But I actually didn't use this when EQ'ing, I only used it at the end to double-check the results. The reason is that I didn't want a completely flat response curve; instead I wanted a "House curve", which is a gradual downward slope from 20hz. The idea behind this is that since the human ear can't hear very low frequencies as well, you want to compensate for that by giving a slight boost in that part of the curve. I found that EQ'ing a flat curve without the calibration file gave me a house curve.


You might want to do some searching on ETF and House Curves at HTF for more info, as there's been a lot of discussion there on these topics.

 

rs_spl.zip 0.2109375k . file
 

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Larry,


to ease your pain, try emailing or calling Doug (the creator of ETF software) and i'll guarantee he has an answer for us regarding hookup and the settings. ETF is compatible with ANY full duplex soundcard so the M-Audio should work fine (i hope).
 

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Discussion Starter · #10 ·
Quote:
Originally posted by JKohn
I'll double check tomorrow, but I'm 99% sure I left that stuff alone. The only thing I changed was the default source in the "Sounds and Audio Devices" Control Panel applet, as mentioned above.


About the SPL meter and a correction file for low frequencies. I have a correction file I got from one of the threads at HTF, and I'm attaching it here. But I actually didn't use this when EQ'ing, I only used it at the end to double-check the results. The reason is that I didn't want a completely flat response curve; instead I wanted a "House curve", which is a gradual downward slope from 20hz. The idea behind this is that since the human ear can't hear very low frequencies as well, you want to compensate for that by giving a slight boost in that part of the curve. I found that EQ'ing a flat curve without the calibration file gave me a house curve.


You might want to do some searching on ETF and House Curves at HTF for more info, as there's been a lot of discussion there on these topics.
Hi John:


Thanks for the response.


Yes, I am familar with the attached file. In researching this I learned that It was developed by Michael Sims. Michael used pink noise when creating his correction file. Since ETF5 uses MLS test signals, which are a type of white noise, I was concerned that this might lead to incorrect measurements.


I have done extensive searching on this and other forums for ETF and house curves prior to posting this thread. I was unable to find anything regarding setting up the Audiophile card. As you are no doubt aware the generic Window Mixer described in the ETF5 help file is quite different from the Delta Monitor Mixer. The Mixer is used to select hardware and software inputs and outputs and to adjust the level of the signal so as to get an OK on the ETF5 application.


With regard to House Curves, apparently there are both proponents and apponents of this technique.


Thanks again for your help.


Larry
 

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Discussion Starter · #11 ·
Quote:
Originally posted by power
Larry,


to ease your pain, try emailing or calling Doug (the creator of ETF software) and i'll guarantee he has an answer for us regarding hookup and the settings. ETF is compatible with ANY full duplex soundcard so the M-Audio should work fine (i hope).
Hi Serge:


Thanks for the response.


I have been in almost daily contact with Doug regarding this and other issues. Doug has been extremely responsive, but he doesn't have an Audiophile card. I have read a posting where a forum member indicates having successully used the Audiophile with ETF5, however so far he has not responded to a private message, so I thought I would start this thread.


I should point out that I have gotten the card to talk to ETF5, but I was getting very unrealistic results, (dips of 55dB). In attempting to investigate this problem I wanted to make sure that I had setup the sound card correctly. I have gone through a number of false starts. One was due to a bad connection to my sound meter, another was due to setting the wrong surround mode on my processor. (Something not mentioned in the equalizer manual). I have been making some progress, and started to make my first set of equalizer adjustments based on the ETF5 measurements. Everything seemed to be going well when doing individual speaker measurements and equalizer adjustments. However, just a few minutes ago I started to measure combined subwoofer and main speakers frequency responses and started running into unsual results again. Its probably something that I've done wrong.


Larry
 

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Discussion Starter · #12 ·
BumP^


Larry
 
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