Simplified REW Setup and Use (USB Mic & HDMI Connection) Including Measurement Techniques and How To Interpret Graphs - Page 683 - AVS Forum | Home Theater Discussions And Reviews
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post #20461 of 20490 Old 09-19-2016, 05:09 PM
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Originally Posted by AustinJerry View Post
I don't recommend placing the Mona Lisa on top of a treatment and expecting it to work.
Too small.

You might want to look here, also:
DIY Custom-Printed Movie Poster Acoustic Panels - cheap!
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post #20462 of 20490 Old 09-20-2016, 06:38 AM
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Question, I have a Pioneer SC-LX89 (US version SC99). With two separate Pre-out subwoofer.

Thinking about to buy the minidsp to boost the lower frequencys

Read the tutorial from Austin Jerry from the minidsp 2x4. I see he is using only one Pre-out on the avr of the subwoofer.

And the two subwoofers out of the Minidsp.

I saw on another tutorial the minidsp is connected on the two Pre-outs and two subwoofers.

What's the better way? I am just reading in.

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Last edited by wackid; 09-20-2016 at 06:54 AM.
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post #20463 of 20490 Old 09-20-2016, 07:00 AM
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Originally Posted by wackid View Post
Question, I have a Pioneer SC-LX89 (US version SC99). With two separate Pre-out subwoofer.

Thinking about to buy the minidsp to boost the lower frequencys

Read the tutorial from Austin Jerry from the minidsp 2x4. I see he is using only one Pre-out on the avr of the subwoofer.

And the two subwoofers out of the Minidsp.

I saw on another tutorial the minidsp is connected on the two Pre-outs and two subwoofers.

What's the better way? I am just reading in.
I use only one pre-out because both pre-outs carry the same mono sub signal. Keep in mind that ultimately you will want to sum all sub signals and apply EQ to the combined signal.
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post #20464 of 20490 Old 09-20-2016, 07:37 AM
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Originally Posted by AustinJerry View Post
I use only one pre-out because both pre-outs carry the same mono sub signal. Keep in mind that ultimately you will want to sum all sub signals and apply EQ to the combined signal.
Is this also true for AVRs running XT32 with SubEQ?

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post #20465 of 20490 Old 09-20-2016, 08:44 AM
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Originally Posted by AustinJerry View Post
I think he was referring to special acoustic panels that have a decorative artwork face, rather than blank fabric. I don't recommend placing the Mona Lisa on top of a treatment and expecting it to work.

I think your biggest problem is at 90Hz, although the peak is in the right channel, you may not hear it. Otherwise, I don't see anything that wrong, especially above 400Hz. I would approach any treatments with caution. Try something, run an REW measurement, and assess whether there has been an improvement. I suspect that the subs are placed where you wife thinks they look good--moving them around might flatten the bass response.

Two other areas you need to assess are bass resonance and specular reflections. The former is measured by the waterfall, and the latter with the ETC. Look in the guide for direction. These two graphs will be very revealing WRT the overall audio quality in your listening room. Very nice room, BTW, and fine speakers all around! I have a non-dedicated room as well, but no wife to corral my treatments frenzy.

GIK Acoustics "Art Panels": http://www.gikacoustics.com/product/...oustic-panels/
Thanks Jerry, your guides have been incredibly helpful, I know I wouldn't have made it this far with measuring without them.

The specular reflections graph is the one I've been dreading seeing with all the reflective surfaces going on haha. I'll run both next week when I have the house to myself.

The subs are kind of tricky, if you see the picture of the front stage, there's actually no place to put one of the subs otherwise I would. The media cabinet and L/R take up all the area I have. So both are placed nearfield in the back of the room. I found having the drivers face each other behind the couch generated the flattest response I could get from various positions I found. Not sure why. I did have one question though with testing places for the subs, does the distance setting matter while I'm moving them around? Ex. I move a sub 5 foot to the left, do I need to recalc the distance before measuring that location, or would that really only impact the integration with the mains? I need to remeasure as well because due to my HDMI output misunderstanding I think I was getting interference from the rear speaker, I know I don't have the filters set optimally yet.

Since you're also the resident Dirac guru, In your opinion if I don't do any treatments due to WAF, do you think adding Dirac would make a substantial improvement? Or would it be a lost cause without additional room investment. I know it's possible to over EQ and I understand my room is the main issue, just trying to work within my limitations. I plan on trying out the Dirac PC free trial eventually, but it'll take me a good while to get enough time to read up on everything and get it implemented properly for a trial run.

Thanks for the compliments on the speakers and room, as well as the link to the panels. I live in Austin as well if you ever want to come by and listen/school me on setup

My setup: Sonus Faber Venere 2.5 and center, Ascend HTM200SE surround, dual Rythmik L12's, Pioneer SC-95, Samsung PN60F8500
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post #20466 of 20490 Old 09-20-2016, 11:31 AM
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Originally Posted by brianmlamb View Post
Thanks Jerry, your guides have been incredibly helpful, I know I wouldn't have made it this far with measuring without them.

The specular reflections graph is the one I've been dreading seeing with all the reflective surfaces going on haha. I'll run both next week when I have the house to myself.

The subs are kind of tricky, if you see the picture of the front stage, there's actually no place to put one of the subs otherwise I would. The media cabinet and L/R take up all the area I have. So both are placed nearfield in the back of the room. I found having the drivers face each other behind the couch generated the flattest response I could get from various positions I found. Not sure why. I did have one question though with testing places for the subs, does the distance setting matter while I'm moving them around? Ex. I move a sub 5 foot to the left, do I need to recalc the distance before measuring that location, or would that really only impact the integration with the mains? I need to remeasure as well because due to my HDMI output misunderstanding I think I was getting interference from the rear speaker, I know I don't have the filters set optimally yet.

Since you're also the resident Dirac guru, In your opinion if I don't do any treatments due to WAF, do you think adding Dirac would make a substantial improvement? Or would it be a lost cause without additional room investment. I know it's possible to over EQ and I understand my room is the main issue, just trying to work within my limitations. I plan on trying out the Dirac PC free trial eventually, but it'll take me a good while to get enough time to read up on everything and get it implemented properly for a trial run.

Thanks for the compliments on the speakers and room, as well as the link to the panels. I live in Austin as well if you ever want to come by and listen/school me on setup
Moving subs around to find the best placement can be time-consuming. Typically, your would turn off room correction during the exercise. As you move the subs, the distance setting should be adjusted to reflect the new placement. Once you have achieved the best placement according to the REW measurement, you should re-run room correction, which should further improve the frequency response. Finally, you should adjust the combined sub distances to achieve the smoothest splice with the mains in the crossover region (the so-called sub distance tweak).

I am a big fan of Dirac, so I will always be of the opinion that adding Dirac will result in an improvement over your current room correction. But will it like magic fix all your issues? I think you should expect incremental improvement, but what issues will remain is hard to predict. Before making this significant investment, you should ask yourself if what you have now is pleasing, and perhaps good enough.
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post #20467 of 20490 Old 09-20-2016, 12:19 PM
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Are there any downsides to running sweeps at -3dBFS (max) vs. the usual -12dBFS? Assuming the AVR's MV is set accordingly to measure at 85-90dB?

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post #20468 of 20490 Old 09-21-2016, 06:26 AM
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Quote:
Originally Posted by AustinJerry View Post
Moving subs around to find the best placement can be time-consuming. Typically, your would turn off room correction during the exercise. As you move the subs, the distance setting should be adjusted to reflect the new placement. .

I will have my mic today (on a FedEx truck , and am new to this process, but have been reading this forum in preparation and have read through the amazing tutorial (twice) that you and others have so meticulously updated over the years in preparation.


Just curious about how to set the distance of the subs in REW if I move them around during testing. Since Audyssey is setting distance as a function of time and not linear distance, if I move my subs around, how would I know what distance to put in REW?


I assume based on what I read that this consideration is most critical when I get to trying to measure the combined response of both subs together, and/or, subs + mains or subs + center, and not really as critical when I measure an individual sub?


Thanks in advance for any wisdom or advice you can share!


--Joe--
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post #20469 of 20490 Old 09-21-2016, 06:38 AM
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Originally Posted by Jbed27 View Post
I will have my mic today (on a FedEx truck , and am new to this process, but have been reading this forum in preparation and have read through the amazing tutorial (twice) that you and others have so meticulously updated over the years in preparation.


Just curious about how to set the distance of the subs in REW if I move them around during testing. Since Audyssey is setting distance as a function of time and not linear distance, if I move my subs around, how would I know what distance to put in REW?


I assume based on what I read that this consideration is most critical when I get to trying to measure the combined response of both subs together, and/or, subs + mains or subs + center, and not really as critical when I measure an individual sub?


Thanks in advance for any wisdom or advice you can share!


--Joe--
The distance is set in the AVR, not in REW, which has no distance settings. The distance is not a factor when measuring an individual sub for placement. Of course, when you look at the combined response, the delay becomes important. One way to get the new distances is to run a quick 1-position Audyssey measurement and look at the delays Audyssey calibrates.
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post #20470 of 20490 Old 09-21-2016, 06:42 AM
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That will probably change anyway once you do the "sub distance tweak," so don't be too anal about it.
Michael

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post #20471 of 20490 Old 09-21-2016, 06:47 AM
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Originally Posted by LastButNotLeast View Post
That will probably change anyway once you do the "sub distance tweak," so don't be too anal about it.
Michael
The delays we are talking about are between the subs, which are very important. The sub distance tweak adjusts the delay for the combined sub signal WRT to mains, but does not alter the delays between the subs.
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post #20472 of 20490 Old 09-21-2016, 06:50 AM
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Quote:
Originally Posted by AustinJerry View Post
The distance is set in the AVR, not in REW, which has no distance settings. The distance is not a factor when measuring an individual sub for placement. Of course, when you look at the combined response, the delay becomes important. One way to get the new distances is to run a quick 1-position Audyssey measurement and look at the delays Audyssey calibrates.
Thanks! I was actually wondering about the single point check and if that would work. Thanks for the info.


--Joe--
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post #20473 of 20490 Old 09-21-2016, 07:49 AM
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Figured why out my HDMI4 sub output was not working. Somehow I had turned off the LFE channel completely . Realized it when I tried watching a movie last night and the bass was disappointing. Thanks for the further elaboration on the delays Jerry, I'm going to re-work the subs using that method because I was ignoring the distance and try and get more of a downward sloping curve built in.

My setup: Sonus Faber Venere 2.5 and center, Ascend HTM200SE surround, dual Rythmik L12's, Pioneer SC-95, Samsung PN60F8500
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New tech to make acoustic panels from: http://phys.org/news/2016-09-acousti...frequency.html

Can't wait but they'll probably cost a fortune.
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post #20475 of 20490 Old 09-23-2016, 06:28 PM
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I finally got my mic and got all set up tonight with REW! I followed the step by step guide and I'm pretty sure I have it all correct, but I have a few questions I was hoping someone could help me with.

1. The guide says that newer umik1 comes with a -18 gain, but mine shows up at +18. Am I missing something, or just misreading the guide? My noise floor (in an isolated basement room) is coming in at 58db, which seems to me like it's really the normal 40 + the 18 gain = 68. Is this correct? There's no way my basement is 58db "at rest", so I'm hoping that's it.

2. The guide says to leave the measurement screen at defaults (which shows a -12 in the guide), but mine is defaulting to -31... should I set this to -18 to compensate for the 18db gain?

3. I ran pink noise through my setup at reference 0 (with Audyssey ON) and am reading 75.8 to 76.8 db depending on the channel. Is this an acceptable level of accuracy (assuming audyssey should have all these set at 75db)?

Sorry for all the noob questions, I read the guide multiple times and have been pouring through this thread for a week and would appreciate any help getting me off the ground so I don't dive in with any simple mistakes up front.

With all that said, I did run a sweep of the combined response of my dual subs (SVS PC2000's), and that graph is attached. I ran the sweep through my center channel with a 100hz crossover. Aside from the treacherous null in the mid 30's, I think the rest below 100 looks reasonably ok for a first shot with no optimization placements yet (I literally just got this all set up . I'd love to hear your thoughts/opinions as I dive into this rabbit hole

Thanks in advance,

Joe
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post #20476 of 20490 Old 09-23-2016, 06:47 PM
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Quote:
Originally Posted by Jbed27 View Post
I finally got my mic and got all set up tonight with REW! I followed the step by step guide and I'm pretty sure I have it all correct, but I have a few questions I was hoping someone could help me with.

1. The guide says that newer umik1 comes with a -18 gain, but mine shows up at +18. Am I missing something, or just misreading the guide? My noise floor (in an isolated basement room) is coming in at 58db, which seems to me like it's really the normal 40 + the 18 gain = 68. Is this correct? There's no way my basement is 58db "at rest", so I'm hoping that's it.

2. The guide says to leave the measurement screen at defaults (which shows a -12 in the guide), but mine is defaulting to -31... should I set this to -18 to compensate for the 18db gain?

3. I ran pink noise through my setup at reference 0 (with Audyssey ON) and am reading 75.8 to 76.8 db depending on the channel. Is this an acceptable level of accuracy (assuming audyssey should have all these set at 75db)?

Sorry for all the noob questions, I read the guide multiple times and have been pouring through this thread for a week and would appreciate any help getting me off the ground so I don't dive in with any simple mistakes up front.

With all that said, I did run a sweep of the combined response of my dual subs (SVS PC2000's), and that graph is attached. I ran the sweep through my center channel with a 100hz crossover. Aside from the treacherous null in the mid 30's, I think the rest below 100 looks reasonably ok for a first shot with no optimization placements yet (I literally just got this all set up . I'd love to hear your thoughts/opinions as I dive into this rabbit hole

Thanks in advance,

Joe
1. The mic has a gain of either 12dB or 18dB. If there is a minus in front of these values in the guide, then it will be corrected.

2. The default measurement level is -12dBFS. If yours is set to -31, then change it back to -12. There is no need to compensate anywhere in REW for the 18dB mic gain. You should be using a calibration file that came with the mic--that is the only compensation required.

3. If you ran The AVR pink noise to check Audyssey levels, keep in mind that the AVR test tones do not have Audyssey engaged. If you were to measure using an external test disk, you might find a slight difference. However, the important thing with speaker levels is that they match each other, not that they are spot-on at 75dB.

As for the measurement sweep, no need to set the lower limit below 15Hz. Are you really expecting output down to 1Hz?? The measurement is not very good. The dip in the low frequency response needs work. If you only have one sub, then adding additional subs would help. At least try to find a better placement for your existing sub.

Is the measurement sub only? If yes, measure sub+center.
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post #20477 of 20490 Old 09-23-2016, 07:19 PM
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Quote:
Originally Posted by AustinJerry View Post
Quote:
Originally Posted by Jbed27 View Post
I finally got my mic and got all set up tonight with REW! I followed the step by step guide and I'm pretty sure I have it all correct, but I have a few questions I was hoping someone could help me with.

1. The guide says that newer umik1 comes with a -18 gain, but mine shows up at +18. Am I missing something, or just misreading the guide? My noise floor (in an isolated basement room) is coming in at 58db, which seems to me like it's really the normal 40 + the 18 gain = 68. Is this correct? There's no way my basement is 58db "at rest", so I'm hoping that's it.

2. The guide says to leave the measurement screen at defaults (which shows a -12 in the guide), but mine is defaulting to -31... should I set this to -18 to compensate for the 18db gain?

3. I ran pink noise through my setup at reference 0 (with Audyssey ON) and am reading 75.8 to 76.8 db depending on the channel. Is this an acceptable level of accuracy (assuming audyssey should have all these set at 75db)?

Sorry for all the noob questions, I read the guide multiple times and have been pouring through this thread for a week and would appreciate any help getting me off the ground so I don't dive in with any simple mistakes up front.

With all that said, I did run a sweep of the combined response of my dual subs (SVS PC2000's), and that graph is attached. I ran the sweep through my center channel with a 100hz crossover. Aside from the treacherous null in the mid 30's, I think the rest below 100 looks reasonably ok for a first shot with no optimization placements yet (I literally just got this all set up . I'd love to hear your thoughts/opinions as I dive into this rabbit hole

Thanks in advance,

Joe
1. The mic has a gain of either 12dB or 18dB. If there is a minus in front of these values in the guide, then it will be corrected.

2. The default measurement level is -12dBFS. If yours is set to -31, then change it back to -12. There is no need to compensate anywhere in REW for the 18dB mic gain. You should be using a calibration file that came with the mic--that is the only compensation required.

3. If you ran The AVR pink noise to check Audyssey levels, keep in mind that the AVR test tones do not have Audyssey engaged. If you were to measure using an external test disk, you might find a slight difference. However, the important thing with speaker levels is that they match each other, not that they are spot-on at 75dB.

As for the measurement sweep, no need to set the lower limit below 15Hz. Are you really expecting output down to 1Hz?? The measurement is not very good. The dip in the low frequency response needs work. If you only have one sub, then adding additional subs would help. At least try to find a better placement for your existing sub.

Is the measurement sub only? If yes, measure sub+center.
Thanks for the quick and thorough reply, much appreciated! I am running dual subs, and the curves represent running the sweep through my center channel with a 100hz crossover.

Yes, I understand that we can't hear infrasonics as low as my scale (and obviously not zero), that was literally just my first few attempts at getting some preliminary curves. My excitement of just seeing it precluded my sense to change the sweep range before I posted it. I know I have a lot of work to do on the subs. I haven't started optimizing yet, I was just wondering if you exclude the dips in the mid 30's, if the rest above that (up to the crossover point) look reasonably OK. Looking for opinions on that, so if/when I am able to reduce the dips in the 30's, I have a benchmark that at least says the rest looks good (assuming I am able to maintain it once I optimize the dips).

Joe
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post #20478 of 20490 Old 09-23-2016, 07:34 PM
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Quote:
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Thanks for the quick and thorough reply, much appreciated! I am running dual subs, and the curves represent running the sweep through my center channel with a 100hz crossover.

Yes, I understand that we can't hear infrasonics as low as my scale (and obviously not zero), that was literally just my first few attempts at getting some preliminary curves. My excitement of just seeing it precluded my sense to change the sweep range before I posted it. I know I have a lot of work to do on the subs. I haven't started optimizing yet, I was just wondering if you exclude the dips in the mid 30's, if the rest above that (up to the crossover point) look reasonably OK. Looking for opinions on that, so if/when I am able to reduce the dips in the 30's, I have a benchmark that at least says the rest looks good (assuming I am able to maintain it once I optimize the dips).

Joe
Here is something you can compare with:




By the way, is that a photograph of the screen you posted? If you look in the upper left corner of the REW screen, there is a camera icon that will take a screen capture. Much better than a photo.
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post #20479 of 20490 Old 09-23-2016, 07:40 PM
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Quote:
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Quote:
Originally Posted by Jbed27 View Post
Thanks for the quick and thorough reply, much appreciated! I am running dual subs, and the curves represent running the sweep through my center channel with a 100hz crossover.

Yes, I understand that we can't hear infrasonics as low as my scale (and obviously not zero), that was literally just my first few attempts at getting some preliminary curves. My excitement of just seeing it precluded my sense to change the sweep range before I posted it. I know I have a lot of work to do on the subs. I haven't started optimizing yet, I was just wondering if you exclude the dips in the mid 30's, if the rest above that (up to the crossover point) look reasonably OK. Looking for opinions on that, so if/when I am able to reduce the dips in the 30's, I have a benchmark that at least says the rest looks good (assuming I am able to maintain it once I optimize the dips).

Joe
Here is something you can compare with:




By the way, is that a photograph of the screen you posted? If you look in the upper left corner of the REW screen, there is a camera icon that will take a screen capture. Much better than a photo.
That looks about as good as it gets, thanks! Yes, it was a picture. My laptop doesn't get a good wifi signal in my basement so I took a pic and am posting from my phone tonight. Once I get this all situated, I'll post better graphs using the tools in REW and the guidelines on posting graphs to the forums.

Joe
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post #20480 of 20490 Old 09-23-2016, 11:01 PM
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It's been an interesting several hours experimenting with REW for the first time. I learned that one of my subs was 8 feet from optimal placement and the cause of a terrible null at 35hz.

I knew my def tech towers with powered woofers were going to be a challenge.., I'm curious for some feedback.

In the graph attached, I show dual subs with Audyssey and then I show dual subs + my mains crossed over at 40hz with audyssey. I moved each sub around individually with no correction to get the best response before re running Audyssey and then generated
this graph.

It seems to me looking at this (no smoothing added), that the addition of my def techs took care of a lot of the major dips, but the overall range of response grew a bit (excluding peaks). Tomorrow I am going to experiment with lowering the gains on the towers and raising the crossovers in hopes I can flatten it out a little more.

The red line is both subs + Audyssey and the purple line is both subs + fronts crossed at 40 + Audyssey.

I've researched this for countless hours, but I'm still new at it, so any feedback would be appreciated.

Thanks,

Joe
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post #20481 of 20490 Old Yesterday, 05:52 AM
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I'm not the best at this either but I think most folks turn OFF Audyssey, run REW and try to get decent responses w/o EQ. Then once positioning is set, then you run Audyssey.

Once that's done you check how it looks and maybe do a bit more tweaking to integrate your sub with your mains via distance and dose tweaks.

PS we both have similar problems in our graphs (that big dip around 100hz).

I'm going to try and combat it wth a higher filters for my sub as my sub is using a MiniDSP. So I'm going to try both a -24db per octave filter and then. A 6db filter to see what either one does...
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I'm not the best at this either but I think most folks turn OFF Audyssey, run REW and try to get decent responses w/o EQ. Then once positioning is set, then you run Audyssey.

Once that's done you check how it looks and maybe do a bit more tweaking to integrate your sub with your mains via distance and dose tweaks.

PS we both have similar problems in our graphs (that big dip around 100hz).

I'm going to try and combat it wth a higher filters for my sub as my sub is using a MiniDSP. So I'm going to try both a -24db per octave filter and then. A 6db filter to see what either one does...
I did run each sub individually without Audyssey to get them as good as I could before running Audyssey on them again. I think the wildcard for me is going to be the combined response of the subs and my powered deftech towers...
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post #20483 of 20490 Old Yesterday, 06:43 AM
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I did run each sub individually without Audyssey to get them as good as I could before running Audyssey on them again. I think the wildcard for me is going to be the combined response of the subs and my powered deftech towers...
DT speakers with powered subs have always presented a challenge. One would normally place the left and right speakers to achieve the best imaging. That position is not necessarily the best for smoothest bass response. Since the subs are part of the speaker, you can't control their contribution to the room's bass response. I don't mean any disrespect, but this is the reason I would never purchase main speakers with built-in subs.

My only recommendation at this time would be to re-evaluate the sub placement by looking at the combined response before running Audyssey. if you can figure out how to include the bass modules of the DT's in the analysis as well, that would be good. There is interaction among the subs that could well suggest a different placement from what you arrive at when measuring them individually.
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post #20484 of 20490 Old Yesterday, 04:16 PM
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Well I did it.........sort of. I couldn't get the DB to read correctly in REW. It was reading 100 db when my handheld spl meter was reading 75-80. Confused.

I finally got my quad SI 18 DS4's installed and moved the SI HT 18's to the back so 6 subs total. I took some measurments and there was a big suckout at 70 hz, I figured it was a phase issue. So I did the phase checking like in austinjerry's tutorial and fixed that by inverting the phase of the front subs. The resultant REQ plot looked good after the filters were applied.

I then ran MCACC and listed to some music after and there was littel to no bass. I undid the phase and the bass was back. I'm so frustrated.

Anywho, I didn't have a chance to rerun the measurments with the phase off again but it sounds pretty good I suppose. I'm not sure what else I can do to help the db drop at 63 hz. Any thoughts appreciated.



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post #20485 of 20490 Old Yesterday, 04:35 PM
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How are you time-aligning the six subs? A little more information would be useful. How far away from the MLP are the subs? Are you applying EQ before running MCACC?

Sorry if you have already described this in an earlier post--I read a lot of stuff on AVS.
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post #20486 of 20490 Old Yesterday, 05:19 PM
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How are you time-aligning the six subs? A little more information would be useful. How far away from the MLP are the subs? Are you applying EQ before running MCACC?

Sorry if you have already described this in an earlier post--I read a lot of stuff on AVS.
Hi jerry. Subs were time aligned as per your instructions and pm's we exchanged. The front 4 subs are 122" from the mlp, the right rear is 134" and the rear left is 140". I made the millisecond conversion via your guide and inputted those numbers to the mini dsp hd. Eq was applied prior to Mccac.

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post #20487 of 20490 Old Yesterday, 06:01 PM
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Hi jerry. Subs were time aligned as per your instructions and pm's we exchanged. The front 4 subs are 122" from the mlp, the right rear is 134" and the rear left is 140". I made the millisecond conversion via your guide and inputted those numbers to the mini dsp hd. Eq was applied prior to Mccac.
Thanks for refreshing my memory. When I did the phase analysis, I measured the front pair and the rear pair, and looked at the phase relationship. The graph with six individual phases is a little difficult to interpret. Did you by chance measure the front four combined, and then the rear two combined?

It is hard to believe that with all those subs you find the bass too weak.
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post #20488 of 20490 Old Yesterday, 08:43 PM
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Thanks for refreshing my memory. When I did the phase analysis, I measured the front pair and the rear pair, and looked at the phase relationship. The graph with six individual phases is a little difficult to interpret. Did you by chance measure the front four combined, and then the rear two combined?

It is hard to believe that with all those subs you find the bass too weak.
I did not measure the front four independent of the rear two. I will do that and repost when I can. It was crazy. When I change the phase back to baseline the base woke right up. The room is 3000 cubic feet.
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post #20489 of 20490 Old Today, 05:44 AM
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I did not measure the front four independent of the rear two. I will do that and repost when I can. It was crazy. When I change the phase back to baseline the base woke right up. The room is 3000 cubic feet.
If I understand your setup correctly, the front four are combined on one input with a common delay. So it makes sense to me to look at the impulse for the combined signal, rather than individual sub signals. Same for the rear pair. We may or not see an out-of-phase condition with this approach.

Secondly, a frequency measurement should be taken when the two signals have polarity reversed, and compare it with the normal polarity. In my case, the polarity reversed configuration produced a better frequency response.
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post #20490 of 20490 Old Today, 09:27 AM
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If I understand your setup correctly, the front four are combined on one input with a common delay. So it makes sense to me to look at the impulse for the combined signal, rather than individual sub signals. Same for the rear pair. We may or not see an out-of-phase condition with this approach.

Secondly, a frequency measurement should be taken when the two signals have polarity reversed, and compare it with the normal polarity. In my case, the polarity reversed configuration produced a better frequency response.
Hi Jerry. I have the front left two on one channel of the minidsp, the front right on another, the rear left on its own, and the rear right on its own. I will get more measurements with the polarity and post it here. Thanks so much for your help.

Matt
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