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I have decided to give REW another try. I have unsuccessful on all previous attempts. I can either run it on a Mac or a Mac running Windows 7. Any recommendation which one to try? It is a MacBool Pro and does have an HDMI out capability. I'm running High Sierra Version 10.13.6.

Is there an uptodate version of the "How To" guide I can look at?

Thanks
 

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If you don't post anything, we can't give you advice. :p
You may as well post what you have for interpretation/discussion purposes so you're ready to do everything "right" with the new system.
Lots to learn just from reading through the thread and looking at what others have done.
I hate to break this to you, but taking the measurements is the EASY part. ;)
Michael
Ok, here we go (said in my best joker voice from the Dark Knight). Thank you all so much for the advice/thoughts/help!
 

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Would it be worth using REW to find the best place for your subs despite the fact that you're going to replace them soon?

I guess, IOW, is the best place in room for a sub the best place for any sub? (Assuming both subs fit into the same spot :))
That would be my understanding, keeping in mind that small changes can have noticeable effects - maybe one sub cabinet is a bit taller, so the driver isn't in exactly the same place, making comparisons difficult.
 

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Ok, here we go (said in my best joker voice from the Dark Knight). Thank you all so much for the advice/thoughts/help!
There is really only one frequency response measurement among the ones you provided that has any usefulness, and that is the Left+right+sub with Audyssey on. The response is not too bad. The other measurements showing various speakers without the sub are uninteresting, so save yourself the time. Typically, what I like to see is Left+sub(s), right+sunb(s) and center+sub(s), all with room correction turned on.

The waterfall graph is not very good, showing quite a bit of bass resonance.
 

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There is really only one frequency response measurement among the ones you provided that has any usefulness, and that is the Left+right+sub with Audyssey on. The response is not too bad. The other measurements showing various speakers without the sub are uninteresting, so save yourself the time. Typically, what I like to see is Left+sub(s), right+sunb(s) and center+sub(s), all with room correction turned on.



The waterfall graph is not very good, showing quite a bit of bass resonance.


Thanks Jerry. That is why I was hesitant to post these. I will take some more measurements like you suggested and repost in the morning. So how would I go about reducing that resonance? Do I need bass traps in the corners? Remember, noob here. These graphs are the first I have done.


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There is really only one frequency response measurement among the ones you provided that has any usefulness, and that is the Left+right+sub with Audyssey on. The response is not too bad. The other measurements showing various speakers without the sub are uninteresting, so save yourself the time. Typically, what I like to see is Left+sub(s), right+sunb(s) and center+sub(s), all with room correction turned on.



The waterfall graph is not very good, showing quite a bit of bass resonance.


Jerry - one question. If you look at the front left and front right graphs why are the lower frequencies so different between the two speakers? On the higher end they are fairly close. On the lower they look almost the opposite of each other.


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Jerry - one question. If you look at the front left and front right graphs why are the lower frequencies so different between the two speakers? On the higher end they are fairly close. On the lower they look almost the opposite of each other.


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Sub placement, room symmetry, wall materials, Audyssey being funky!
I haven't read your earlier posts but I gather the room is small due to no low frequency room gain or you are using a small sub? Mine was 1500 cubic feet (low ceiling) with similar response before adding multiple subs.
 

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Brettus - the FL and FR were run w/o sub so I get why you said small sub. Room is approximately 18’ 3” x 15’ 2” w 10’ ceiling for right around 3000cf. I am going to run the LCR with my sub this morning.


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There is really only one frequency response measurement among the ones you provided that has any usefulness, and that is the Left+right+sub with Audyssey on. The response is not too bad. The other measurements showing various speakers without the sub are uninteresting, so save yourself the time. Typically, what I like to see is Left+sub(s), right+sunb(s) and center+sub(s), all with room correction turned on.

The waterfall graph is not very good, showing quite a bit of bass resonance.

@AustinJerry attached are the new REW measurements with audy on and the sub on. Yours and others advice would be appreciated.
 

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** Man of Leisure **
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Thanks Jerry. That is why I was hesitant to post these. I will take some more measurements like you suggested and repost in the morning. So how would I go about reducing that resonance? Do I need bass traps in the corners? Remember, noob here. These graphs are the first I have done.


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Resonance is influenced by several factors. The primary factors are room dimensions, type of walls and floor, and furnishings, all difficult to change or control. Strategically placed treatments, additional subs, and sub placement are ways to mitigate the issue. And, of course, the level of effort you take depends on how you think the bass sounds.
 

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Resonance is influenced by several factors. The primary factors are room dimensions, type of walls and floor, and furnishings, all difficult to change or control. Strategically placed treatments, additional subs, and sub placement are ways to mitigate the issue. And, of course, the level of effort you take depends on how you think the bass sounds.
Thanks @AustinJerry. This setup is definitely short term now. I am going to build 1099's for LCR and then two subs designed by @LTD02 that use the UM18-22's. I am thinking that a second sub near the R speaker will help that dip in the low end that I am seeing in the R w Aud w Sub measurement. My room is approximately 18' 3" x 15' 2" x 10' and 300cf. This room is built on a concrete slab. The rest of the house is over the basement. Walls are painted drywall and I plan on adding absorption panels behind the LCR and on the front (display) wall and the back (couch) wall. Once I get everything else built we will see what bass traps I need and incorporate any advice that this group gives me.

Looking forward to your thoughts on the measurements I posted earlier.

Thanks!

Chip
 

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If you look at the front left and front right graphs why are the lower frequencies so different between the two speakers? On the higher end they are fairly close. On the lower they look almost the opposite of each other.
Lower frequencies radiate like a lantern, so they are much more affected by the room than higher frequencies, which beam like a flashlight. So at lower frequencies you're hearing mostly the room while at higher frequencies you're mostly hearing direct sound from the speakers. Which means that small inconsistencies (placement, room shape, etc) can result in big differences at low frequencies.
 

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I got a reasonable deal(relative to where I live) on a used Dell Latitude E6430 for the equivalent of ~225$. Thanks to everyone that provided suggestions!
So, does it support 7.1 HDMI connections with REW?
 

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I have decided to give REW another try. I have unsuccessful on all previous attempts. I can either run it on a Mac or a Mac running Windows 7. Any recommendation which one to try? It is a MacBool Pro and does have an HDMI out capability. I'm running High Sierra Version 10.13.6.

Is there an uptodate version of the "How To" guide I can look at?

Thanks
Hi Chuck,
Since nobody else got back to you on this, I'll mention that AustinJerry has put together an exhaustive guide to using REW with HDMI, which is regularly updated by him pretty frequently:
https://www.dropbox.com/s/zdhq72a1puyyxpr/REW 101 HTS Current Version.pdf


I know next to nothing about using REW with a Mac or a Windows emulator, but if you go to Page 4, there's several Mac resources listed which can hopefully point you in the right direction. You may want to ping Markus (marcus767) or one of the authors of the linked content for more information.
 

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I'm running REW via a Mac (just cannot get audio out to work over HDMI from my Dell XPS laptop, damn frustrating!!). Anyone know why i'm not getting a timing reference when I measure my subs?? I also think the timing reference on the LCR is not working correctly. Instead of coming from the Left channel, it seems to be coming from the channel i'm trying to measure (i.e. if i'm measuring the Centre channel, I hear the timing reference coming from the Centre channel). I'm assuming the timing reference is the short chirp prior to the REW sweep?
 

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I cant get L+R+Sub to run on REW, only L+Sub or R+Sub. Ive generated some waterfalls but not sure if im doing it right. I think ive set all limits correctly, but I dont have much in the way of room treatments up yet. Its heavy carpet on the floor, and a heavy curtain along entire back wall, a front baffle wall covered in foam absorbers. It looks like the sound is decaying very rapidly, ie the waterfall looks almost to good to be true?? I also have this large null at ~67hz (sub), do you think this could be an issue with the sub distance ive put into the Anthem AVM60 (the crossover to the mains is at 80hz)? Its currently set to the actual distance, but might play around with the sub distance tweak and see if that helps?
https://www.dropbox.com/s/ec0q2ofcswct9zh/030918 v1.mdat?dl=0
 

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I cant get L+R+Sub to run on REW, only L+Sub or R+Sub. Ive generated some waterfalls but not sure if im doing it right. I think ive set all limits correctly, but I dont have much in the way of room treatments up yet. Its heavy carpet on the floor, and a heavy curtain along entire back wall, a front baffle wall covered in foam absorbers. It looks like the sound is decaying very rapidly, ie the waterfall looks almost to good to be true?? I also have this large null at ~67hz (sub), do you think this could be an issue with the sub distance ive put into the Anthem AVM60 (the crossover to the mains is at 80hz)? Its currently set to the actual distance, but might play around with the sub distance tweak and see if that helps?
https://www.dropbox.com/s/ec0q2ofcswct9zh/030918 v1.mdat?dl=0

To measure L+R+Subs, output the REW test signal to HDMI1 and HDMI2 simultaneously. The left and right speakers should be set to "Small" with crossovers. By virtue of bass management, the subs will output frequencies below the crossover point.

You do NOT want to measure Mains+Subs by sending the REW signal to Main Speaker (HDMI1,2, or 3) along with HDMI4 (LFE). If you are doing that, then don't.

All of the measurements show a peculiar response curve below 100Hz, with a dip at 63Hz (as you observed), and then a pretty dramatic rise down to 15Hz. I definitely think experimenting with the sub distance would be a thing to try. Also as you noted, the sub only measurement is showing a narrow but deep dip at 63Hz. The sub distance tweak will not address this dip--the tweak only affects the interaction between subs and mains. You need to figure out what is causing the dip. I don't see any issue looking at Group Delay, so the dip should be correctable. BTW, what is the crossover value?

The left and right channels have a peak at 140Hz, which could be lowered by PEQ. Not sure why ARC is not taking care of this. Several years ago, I compared ARC to Audyssey and found that Audyssey does a better job, especially in the low end. I use Dirac Live now, which is an even better solution.

To smooth out the low frequency response, the usual advice is appropriate--experiment the sub distance, try different sub placements, or even consider adding additional subs.

The waterfall graphs look good. The ETC is showing quite a few spectral reflections (peaks above -20dB in the first 20ms). Room treatments would help in this area.

As for the timing reference on the sub channel, I don't know why this is not working. The other measurements are showing a timing signal on the left speaker.
 
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