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Dayton OmniMic Precision Measurement System - Page 69

post #2041 of 2086
Quote:
Originally Posted by Phillips751 View Post

Done some experiments / reading with EQ.

Conclusion:
1. Using too many filters can be very detrimental to the sound.
2. The way EQ is applied is extremely important
2. Flat response isn't the best sound.
3. There is alot more to acoustics than flat response.


All valid points.

Regarding flat response, you're right it's not best. However smooth response certainly is.

Ideally, one needs to pursue physical placement optimization to achieve the most smooth platform from which to begin. I've recently discovered a placement strategy that allows me to not use any response EQ'ing in my 3 sub, sub system.
post #2042 of 2086
Quote:
Ideally, one needs to pursue physical placement optimization to achieve the most smooth platform from which to begin. I've recently discovered a placement strategy that allows me to not use any response EQ'ing in my 3 sub, sub system.

Are you able to share this with us?
post #2043 of 2086
Quote:
Originally Posted by Phillips751 View Post

Are you able to share this with us?

The placement? Sure, it's simply experimentation. It's nothing more than the most recent combo that yielded great results. When stating "placement strategy", I'm just saying the normal stuff, .. moving everything around until it hits. As I'm sure you realize, every room is different and yields differing results.

Multiple subs, minimum of three, is a real strong tool for smooth and seamless blending of subs w/the mains. Also, the ability to align in time the subs is key, and varying the low pass of the subs is helpful too. Just as much control as possible, combined w/the ability to measure the resultant changes.

The particular set-up I was referring to (nothing special); my IB front-left (it ain't moving cool.gif ), one sub front-right but not fully in the corner, .. pulled off both boundaries, and another sub about 5'-6' diagonally behind and to the side of my LP. As I said, since the rooms vary so much, the specifics aren't as important as the tools.

I'm changing some seating around again soon, so I'll have to continue experimenting again.
post #2044 of 2086
Quote:
The placement?

This is where i find the Omnimic package to be great, it is in real time.

I currently have REL Strata 5 x 2 and they are very musical.
I also have Velodyne DD15 + DD12 they are fantastic subs as well, very versatile.
The DD15 i find to be excellent in 2 channel music, with there PEQ it makes it even better.
Alot of people forget about placement, not always ideal but get best possible under conditions.

I find that there seems to be to much of, ha put the sub here and the PEQ will make it all better.
Quote:
Sure, it's simply experimentation. It's nothing more than the most recent combo that yielded great results. When stating "placement strategy", I'm just saying the normal stuff, .. moving everything around until it hits. As I'm sure you realize, every room is different and yields differing results.

Ok yeah it also comes down to personal taste as well.

The Omnimic isn't a magic tool that does everything, just tells you what possibly you could do to improve the sound etc.
It all looks easy but there is a learning curve to all this to people who want to make the most of the Software.
Quote:
Multiple subs, minimum of three, is a real strong tool for smooth and seamless blending of subs w/the mains. Also, the ability to align in time the subs is key, and varying the low pass of the subs is helpful too. Just as much control as possible, combined w/the ability to measure the resultant changes.

Absolutely dual or more is a advantage.

Matter of interest do you run them mono or stereo, i have tried both. The RELs are currently setup as stereo high level?

The particular set-up I was referring to (nothing special); my IB front-left (it ain't moving cool.gif ), one sub front-right but not fully in the corner, .. pulled off both boundaries, and another sub about 5'-6' diagonally behind and to the side of my LP. As I said, since the rooms vary so much, the specifics aren't as important as the tools.

So much variation in sound in general.
Quote:
I'm changing some seating around again soon, so I'll have to continue experimenting again.

Yep lucky i have a very flexible wife, all the test tones and changes.

Just recently bought a DSpeaker Antimode Dual Core 2.0 for my mains, very versatile.
It has alot of adjustments that people don't realize.
post #2045 of 2086
Two quick Q's.

- has anyone got this working on Windows 8?
- Can you do overlays on a single graph. (For instance to one curve showing EQ applied, and one without). I know REW can do this.
post #2046 of 2086
Quote:
Originally Posted by eiger View Post

Two quick Q's.

- has anyone got this working on Windows 8?
- Can you do overlays on a single graph. (For instance to one curve showing EQ applied, and one without). I know REW can do this.


I can't see any reason why it wouldn't work on Windows 8.

Yes you can do overlays i do them to compare different settings on my Antimode Dual Core 2.0.
post #2047 of 2086
Hello to everyone.

I just received my omnimic kit and I am thrilled to find out what results I will get in my dedicated home theater (I built it myself and it took me more than 8 years to complete...now only the projector is missing!). I have read through this whole thread and I have learned more than a lot! BTW I am using the software on Windows 8 and it works perfectly!

Since I dont know much about room analysis software and it is the first time I ever get to do this, I was wondering if I did everything right? Please, comment, correct me, ask me questions...I want to learn from this!

First of all, using the omnimic SPL, c-slow, I measured a background noise level of 38.6 dB. Does that make any sense? the room is well soundproofed. Here is the graph I got:



How come the highest bar I see is at 25 dB?

Then, turning all Audyssey stuff off on the AVR, I ran a short sweep from the omnimic DVD test tone, playing only the LFE track. Here is the frequency response I got (no smoothing) and the corresponding waterfall, recorded with the mic facing down, main listening position:





I will experiment further tonight, but so far, do my readings make any sense?

Thanks a lot! Again, please correct me if I am wrong, and dont hesitate to ask for clarifications, sometimes my english is not perfect...smile.gif
post #2048 of 2086

Yep, everything looks fine.  You are on the right track.

post #2049 of 2086
Tha 25 dB is he sound level for a band of freq; they all add togeher to produce a higher total dB SPL.

I find i curious that the high freq are rising, unless that's from the weighting.

I'm also puzzled that your unsmoothed frq resp is so smooth.
Quote:
Originally Posted by stef2 View Post

First of all, using the omnimic SPL, c-slow, I measured a background noise level of 38.6 dB. Does that make any sense? the room is well soundproofed. Here is the graph I got:

post #2050 of 2086
Quote:
Originally Posted by noah katz View Post

Tha 25 dB is he sound level for a band of freq; they all add togeher to produce a higher total dB SPL.

I find i curious that the high freq are rising, unless that's from the weighting.

I'm also puzzled that your unsmoothed frq resp is so smooth.

Thanks for the explanation! bTW I have tested again the frq resp of my sub, no smoothing, and the result is the same...is it too smooth to be true???

By the way, anybody bought the new test tones DVD? I wonder what setting should be used on the AVR to play it correctly (with no processing). Should I choose DD 5.1? that would be my guess since chosing stereo on my AVR doesnt output center and surrounds sounds, and with all channels stereo (party mode) the sound comes from more than one speaker (for example, if I choose to test only the center channel on the DVD, my FR, FL and center channels play the sound in party mode...)
post #2051 of 2086
I would run either a 1/12th or 1/24th with Omni.
post #2052 of 2086
Quote:
Originally Posted by exojam View Post

I would run either a 1/12th or 1/24th with Omni.

Then, the response would be even smoother. I thought no smoothing should be used for low frequencies? that is what I did.

Also, about SPL readings, I found out today that I cound certainly not trust the omnimic SPL to accurately analyse the background noise in my HT. The room is completely silent, and it reads 38.8 dB (c weighted). If I add noise to the room by playing a pink noise from my FR and FL speakers, I have to increase that noise quite a bit before the SPL starts reading above 38.8 dB (0 being calibrated to reference level, I have to increase the volume on my AVR above -52 before the SPL starts moving up...)
post #2053 of 2086
Quote:
Originally Posted by stef2 View Post


Then, the response would be even smoother. I thought no smoothing should be used for low frequencies? that is what I did.

Also, about SPL readings, I found out today that I cound certainly not trust the omnimic SPL to accurately analyse the background noise in my HT. The room is completely silent, and it reads 38.8 dB (c weighted). If I add noise to the room by playing a pink noise from my FR and FL speakers, I have to increase that noise quite a bit before the SPL starts reading above 38.8 dB (0 being calibrated to reference level, I have to increase the volume on my AVR above -52 before the SPL starts moving up...)

A silent room reading around 40db is common, in fact most will read louder.  So your reading is probably correct.

post #2054 of 2086
Quote:
Originally Posted by stef2 View Post

Then, the response would be even smoother. I thought no smoothing should be used for low frequencies? that is what I did.

Look at the amount of data you get on none and compare it to a 1/12th or 1/24th, even though they may be smoother is is not a straight line from one point to another. I used Omni a ton when it first came out and ended up using what I suggested, you can use the none if that is what you feel gives you a better result.
post #2055 of 2086
Quote:
Originally Posted by primetimeguy View Post

A silent room reading around 40db is common, in fact most will read louder.  So your reading is probably correct.

Then, how come the SPL reading doesnt move at all when I add a substantial amount of noise to the room? the noise in the room gets clearly louder as I increase the intensity of the pink noise being played but the SPL doesnt move at all until I increase the volume above -52 on my AVR? only above that significant level of added noise does the SPL start to move up...I think the point where the SPL reading barely starts to increase must be the minimum reading it can give...

Explained differently, If I start a reading with the omnimic SPL an a pink noise playing at -55 on my AVR it says 39db is the noise level in my room. If I stop the pink noise, the level of noise CLEARLY decreases (by ear) a lot in the room but the SPL doesnt move at all...
post #2056 of 2086
Quote:
Originally Posted by stef2 View Post
 
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Then, how come the SPL reading doesnt move at all when I add a substantial amount of noise to the room? the noise in the room gets clearly louder as I increase the intensity of the pink noise being played but the SPL doesnt move at all until I increase the volume above -52 on my AVR? only above that significant level of added noise does the SPL start to move up...I think the point where the SPL reading barely starts to increase must be the minimum reading it can give...

Explained differently, If I start a reading with the omnimic SPL an a pink noise playing at -55 on my AVR it says 39db is the noise level in my room. If I stop the pink noise, the level of noise CLEARLY decreases (by ear) a lot in the room but the SPL doesnt move at all...

 

Assuming 0 on your receiver is reference level, -55 is extremely low volume.  I forget what level the noise is recorded at but if it is -30 then at 0 on the volume dial you will still only read 75db.  Therefore -55 on the dial would only give you 20db which is lower than your noise floor.

post #2057 of 2086
Hi has anyone used Omnimic to Time Align that can share?

I am trying to Time Align the sub with the mains and also both mains.

Thank you
post #2058 of 2086
I had my V1 mic recalibrated, fired up Omnic and imported the calibration file. The problem is it appears to be exactly 20 dB too low compared with Audyssey Pro calibration levels. I'm reading 55 dB(+/- a decibel) on my Denon 4311 test tones.

Does anyone have any idea if it is a setting I need to change somewhere or is it a bad calibration? The pre-calibrated mic was dead-on with SPL readings.

Thanks!
post #2059 of 2086
Not that there's any activity with Omnimic any more, but as a heads up to potential Windows 8 owners, there is an issue with Omnimic mic calibrations.

My laptop is a Lenovo Ideapad Yoga 13 with Windows 8 64 bit. I have a recalibrated V1 mic and a V2 mic and they are both exactly 20 dB low on this laptop. My Windows 7 laptop has both mics perfectly calibrated.

Dayton tech support has no idea what the problem is and I have uninstalled and reinstalled both Omnimic and my audio drivers multiple times with no luck. Still 20 dB low on both mics.

Of course this Win 8 laptop has an HDMI out for my display to make it convenient to monitor measurements and the Win 7 doesn't! Omnimic has been plug and play up to this point, so this is a disappointing bug.
post #2060 of 2086
Goodoc and others --

I just ran into that bug myself the past week and it took me a while to find the workaround (other than convincing Microsoft that they needed to fix their Win8 built in USB recording drivers!). Sent this to PE a few days ago, they probably haven't gotten it out to all their tech help guys.
  • Make sure OmniMic isn't running.
  • Find the Omnimic.exe file (probably in C:\Program Files\OmniMic or C:\Program Files(x86)\OmniMic) with the file browser, and right-click on its file name.*
  • Then choose "Properties" from the menu that appears
  • Then click on the tab labelled "Compatibility", in the "Compatibility mode" box select "Windows XP (Service Pack 3) and put a check in the checkbox labelled "Run this program in compatibility mode for:"

* (You can instead do this process for any icon or menu shortcut that you use to start OmniMic, but then it would only apply the fix when you run OM that way).

I have no idea why this happens in Windows8. From Google searching I see that people have been having the same problems with other USB microphone or recording hardware in Win8. I suspect it is a bug in Win8 rather than some "feature", as the effect in normal audio programs of it is to throw away about 4 bits of resolution and make recording seem very weak".

(It might be a good idea to do this also with any programs you have that you use with USB microphones or similar functionality.)
post #2061 of 2086
I love you man!!!
I got no response to my first post and figured I was just being my usual ****** self and had some stupid setting wrong. But then I tried a V2 mic with same exact problem! Knew it couldn't be two bad mics and confirmed on win7 machine.

I will try fix tomorrow as too late to run tones tonight and I will report back.

Again, the Bill!!
post #2062 of 2086
Scratch that, already tested it and it works. I can also confirm that running in win 7 compatibility mode does not work. I'm sure you tested that as well Bill but I had to try it myself. That's Windows for you, runs in Windows 7 but not in Windows 7 compatibility mode, lol
post #2063 of 2086
Quote:
Originally Posted by Phillips751 View Post

Hi has anyone used Omnimic to Time Align that can share?

I am trying to Time Align the sub with the mains and also both mains.

Thank you

I was curious myself. I used the 5.1 test dvd and the corresponding tracks and the whole millisecond thing doesnt change much at all as I am changing the sub distance setting on a very up to date Emotiva umc-200 preamp. I am also in search of the answer myself. Let me know as soon as you do. I was really mad when I found out xtz even has a specific alignment application within it:(
post #2064 of 2086
Quote:
Originally Posted by stef2 View Post

Thanks for the explanation! bTW I have tested again the frq resp of my sub, no smoothing, and the result is the same...is it too smooth to be true???

By the way, anybody bought the new test tones DVD? I wonder what setting should be used on the AVR to play it correctly (with no processing). Should I choose DD 5.1? that would be my guess since chosing stereo on my AVR doesnt output center and surrounds sounds, and with all channels stereo (party mode) the sound comes from more than one speaker (for example, if I choose to test only the center channel on the DVD, my FR, FL and center channels play the sound in party mode...)

I only used dd 5.1 with the test dvd and it worked flawlessly (dont forget to change the response to dvd mode in the upper tabs). Sometimes you must pull speaker connects for the dd 5.1 test dvd too, so be aware they are accesible. I just remember i had to do that when i was using it for certain reasons to isolate the center from being mixed with low frequency subs, etc.
post #2065 of 2086
Quote:
I was curious myself. I used the 5.1 test dvd and the corresponding tracks and the whole millisecond thing doesnt change much at all as I am changing the sub distance setting on a very up to date Emotiva umc-200 preamp. I am also in search of the answer myself. Let me know as soon as you do.

Yeah i only have the original track, no 5.1 tracks.

i can't see the difference in the Impulse for the mains and subs, thought that the 5.1 was suppose to make this clearer, maybe not.

Another way is to change the distance settings in the preamp and check on the flight through the crossover range e.g 80hz crossover look between 40 - 160hz range to get the flattest range. If this doesn't give you any results let me know i might have a option, but try first.

Does your preamp work in milliseconds or distance (feet or meters), same result just different way to calculate.
Quote:
I was really mad when I found out xtz even has a specific alignment application within it:

Yep looks like it works really well.
post #2066 of 2086
My preamp works with feet with a decimal ex: 3.2 ft. With lfe(subwoofer) alignment I didnt see any diffrence with the correct app for timing window. I will go ahead and check the frequency response you mentioned, that should give me some better results...I'm hoping. My entire calibrated system has be to be calibrated again after taking everything down for replacing house windows, my room being one of them.
post #2067 of 2086
Quote:
Originally Posted by pnutbutter81 View Post

My preamp works with feet with a decimal ex: 3.2 ft. With lfe(subwoofer) alignment I didnt see any diffrence with the correct app for timing window. I will go ahead and check the frequency response you mentioned, that should give me some better results...I'm hoping. My entire calibrated system has be to be calibrated again after taking everything down for replacing house windows, my room being one of them.

Let us know how you get on.
post #2068 of 2086
Is there any way of measuring, saving, and later importing the impulse response in Omnimic instead of re- measuring?

I need a 5 meter USB cable, what is the longest i can use with Omnimic without it having to be powered?

Thanks in advance
Edited by Phillips751 - 11/19/13 at 12:55am
post #2069 of 2086
Hey guys, I 'm at post 100, trying to catch up to the thread...

Received my omnimic V2 last week. Came with a free stand which was cool.

Until then if anyone has any information that would help a newbie to the world of audio measuring I would appreciate any links, instructions, etc. I think this is a good all in one package, but until I learn how to use it, its just cool looking test equipment with the mic on the stand hooked up to my laptop. Looks fancy and makes me look smart when people see it, lol.

I ordered a book that should be here in a few days: http://www.amazon.com/gp/product/0240520092/ref=oh_details_o00_s00_i00?ie=UTF8&psc=1 I heard this is a good book to read.

I downloaded the PDF file from the thread starter, all the other links are expired.

Also might mention if there is anyone who knows how to use this and lives in my area I would appreciate them making time to help out with measurements.... of course I would compensate you for your efforts.

I want to learn how to test and understand exactly what I am testing for and looking at so when I build my HT. It should be very useful when placing all my room treatments and generally a good tool for my audio/HT toolbox smile.gif


Thanks!!
Edited by 316 - 1/30/14 at 4:08pm
post #2070 of 2086
Quote:
Originally Posted by 316 View Post

Hey guys, I 'm at post 100, trying to catch up to the thread...

Received my omnimic V2 last week. Came with a free stand which was cool.

Until then if anyone has any information that would help a newbie to the world of audio measuring I would appreciate any links, instructions, etc. I think this is a good all in one package, but until I learn how to use it, its just cool looking test equipment with the mic on the stand hooked up to my laptop. Looks fancy and makes me look smart when people see it, lol.

I ordered a book that should be here in a few days: http://www.amazon.com/gp/product/0240520092/ref=oh_details_o00_s00_i00?ie=UTF8&psc=1 I heard this is a good book to read.

I downloaded the PDF file from the thread starter, all the other links are expired.

Also might mention if there is anyone who knows how to use this and lives in my area I would appreciate them making time to help out with measurements.... of course I would compensate you for your efforts.

I want to learn how to test and understand exactly what I am testing for and looking at so when I build my HT. It should be very useful when placing all my room treatments and generally a good tool for my audio/HT toolbox smile.gif


Thanks!!

 

Using the OmniMic is really, really easy. Literally plug and play. The hard part is knowing what the graphs mean and how to interpret them etc. I was in exactly your position some time back.

 

There is a really good thread here on AVS which can help you hugely with the latter (you don't really need help with OM as it is so easy to use - and this thread will help on any small issues you may encounter).

 

The thread is basically a REW thread (sorry to mention that in an OM thread - REW is much more complicated than OM and I use both so I am unbiased). But it also a thread for 'first time measurers' and it has some great advice on how to interpret the graphs, how to improve the room, how to follow proper measuring protocols etc. It doesn't matter that it is a REW thread because your OM will get you measurements that are every bit as good, so you can ask for advice on the things I mentioned regardless of your measuring gear platform.

 

Just a thought.

 

The thread is linked in my sig.

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