Corner Loaded Subs-need help

[dan711]

I've been recently posting over @ AVS so I thought I would bug folks on this forum. I realize that many post on both forums. i.e. AustinJerry, who has given me sound advice.

I've been having issues with my sound. It just doesn't seem right. I make adjustments and I get thundering low bass but no midbass. I make more adjustments and vice versa happens.

My room is a problematic square room 20 x 21 w/8' ceiling. I finally decided to corner load my subs basically because many believe that it would be beneficial and REW room sim shows it to be the best placement.

Below are my measurements from today. Two UXL's-one each in the rear corners HPF @ 20hz. Two pa460's one each in the front corners HPF @ 40hz.

First link is subs, second link is subs + center after running Yamaha YPAO-room correction. All measurements use acoustic timing reference with the center channel.

I have level/gain matched subs and tweaked distances 20 or 30 times. I can't get a decent measurement, IMO to save my life.

Any thoughts or suggestions?

https://www.dropbox.com/s/d275kwp26nfgp44/corner loaded subs.mdat?dl=0

https://www.dropbox.com/s/ve3sppasfi7wckj/corner subs YPAO.mdat?dl=0

 

[Wayne A. Pflughaupt]

No need to make us go through the trouble of Dropbox. You can upload your .mdat file to your post.

Regards,
Wayne

 

[dan711]

No need to make us go through the trouble of Dropbox. You can upload your .mdat file to your post.

Regards,
Wayne

sorry, was thinking about the routine on other sites.

 

[Todd Anderson]

Hey @dan711 ... first off, welcome to AV NIRVANA. Glad you're here!

Was just looking at your first file and the measurement of dual subs and subs plus center and it looks pretty decent to me... but not as robust as the subs alone.
Just to understand, what kind of speakers are you using with your subs? What's the crossover setting?

YPAO, like several other popular room correction suites, has a tendency to reset speaker settings from "Small" to "Large" once you've run room correction. Have you gone back into your settings to make sure your system isn't defaulting speakers to Large?

From the looks of your all subs measurement and your subs + center measurement, that might be what's happening.

 

[Sonnie Parker]

Welcome to AV NIRVANA

I will be blunt about it... you more than likely will need something better than YPAO to get it to the best it can be. Dirac Live would probably solve the issue for you and give you an overall smooth response. HOWEVER, if you are only willing to work with what you have now, it may just take a lot of experimenting with placement and various crossover points between 60-80Hz... try different distance settings for one of the subs, if you have that capability... try firing one of the subs into the corner (fixed an issue for me once).

And... what Todd said.

 

[dan711]

Thanks Todd and Sonnie. This is my first venture with Yamaha and YPAO however, not my first go-round with room correction i.e. Audyssey and MCACC. I know of the issue with most room correction software attempting to label speakers as large. Unfortunately, it's REW measuring that is frustrating me. Over the past few weeks, I have moved subs, speakers and my MLP (only slightly) so many times it makes my head hurt. I've changed crossover levels, speaker levels, checked polarity, phase, level, gain and probably, no exaggeration, run over 200+ measurements in REW. Finally I decided to follow REW's room sim suggestion and corner load all 4 subs. The low bass is nice, if almost overwhelming but, my mid-bass has once again disappeared.

I've attached my last measurement from 5 hours of measuring today. I just don't get what's happening between 70-120hz.

@Todd Anderson, I have two sets of speakers (SVS Ultra bookshelves/center and DIYSG Fusion 8's) that I have swapped in and out recently. Neither has produced good results when measured along with my subs.

dan

 

[John Mulcahy]

What do the left/right/centre responses look like without the subs? What crossover frequency are you using?
Little difficult to tell with measurements only going to 300 Hz, but in the earlier centre+subs measurement the subs level looked low relative to the centre.
BTW, something in your room is making a racket at 90 Hz, see it in all the measurements.

 

[dan711]

John,

I've attached the file with the center isolated. I'll do more searching later today in order to dig up the mains. Not sure what is causing the craziness @ 90 hz. I've tried both center channels I have and they have had similar results. I'm crossing over at 90 hz but, have tried 80 and 100 as well. I've pulled the center out as much as 3ft into the room as well as pushed it up against the wall for testing purposes. That congestion centered around 90 hz does not go away.

What do the left/right/centre responses look like without the subs? What crossover frequency are you using?
Little difficult to tell with measurements only going to 300 Hz, but in the earlier centre+subs measurement the subs level looked low relative to the centre.
BTW, something in your room is making a racket at 90 Hz, see it in all the measurements.

 

[John Mulcahy]

The 90 Hz peak is something in the environment, an external noise. The centre response shows a strong reflection at about 5.6 ms that won't be helping. There is also a very large (> 20 dB!) peak in the response centred on 7.5 kHz which is very unusual and a bit alarming. Do you have any EQ applied?

 

[jtalden]

Are you sure you are not accidentally using the internal mic input?

I notice in the info panel that the input listed is 'HD Audio 1'. I think input should be something more like; USB UMIK-1. Check your settings of the ASIO4ALL control panel to highlight the UMIK mic so that it is available to select in REW. I am sure there are several writeups showing the detail on just how to do this.

Note: I am not a USB mic user so I may be wrong on the point.

 

[John Mulcahy]

Good spot! It is a UMM-6 I think, but it won't be the HD Audio Mic input.

 

[Todd Anderson]

Are you sure you are not accidentally using the internal mic input?

I notice in the info panel that the input listed is 'HD Audio 1'. I think input should be something more like; USB UMIK-1. Check your settings of the ASIO4ALL control panel to highlight the UMIK mic so that it is available to select in REW. I am sure there are several writeups showing the detail on just how to do this.

Note: I am not a USB mic user so I may be wrong on the point.

Great... great... point. I've had REW unsuspectingly default to my laptop's internal mic and it has left me scratching my head. You definitely have to go into the settings to be sure you're using your external mic

 

[dan711]

@John Mulcahy No eq applied so not sure whats happening at 7.5 khz. There was no external noise during my last measuring session. House/room was dead quiet.

@jtalden ASIO control panel ( umm-6 was not highlighted anymore ), Todd was right in assuming it defaulted back to internal mic. HD audio 1 was highlighted in the input box.

I changed the ASIO control panel back to umm-6. Only input choices that show up presently under the input tab are as followed.

HD audio mic 1
HD audio mic 2
HD audio stereo 1
HD audio stereo 2
micin 1
micin 2

Which do I use? What is micin?

 

[jtalden]

I am thinking you may need to follow Jerry Austin's guide starting at pg 41 to sort it out.

 

[John Mulcahy]

micin is probably the UMM-6.

 

[dan711]

It appears that is correct. When umm-6 is highlighted under device list; micin 1 & 2 appear under input. If I remove umm-6 from device list then micin 1 & 2 disappear.

Now, thanks for the help I received here, I think I can properly measure. I'll get some measuring done this weekend and report back.

micin is probably the UMM-6.

 

[Todd Anderson]

I'm curious to see how this plays out for you. Good luck!

 

[dan711]

Todd or anyone that may care.

Took some measurements today after making sure ASIO control and mic inputs were corrected.

First set of measurements are center, left, right and l & r combo. I took apart my DIYSG Fusion 8 center and made some adjustments to the enclosure as well as re-wiring. It definitely made a positive improvement. I didn't touch the L & R.

Second set of measurements is subs separately, together and with center. Nice improvement at the crossover now.

Third set of measurements is initial subs/center before peq and after. Tried to knock down that peak centered around 55 hz. I cut 10db over all subs @ 55 hz. Only boost was on the low end. A 2db boost @ 25 hz, UXL's only. I tried many cuts but none really worked well.

When you get some free time; any thoughts or suggestions would be welcomed.

I'm curious to see how this plays out for you. Good luck!

 

[Todd Anderson]

I guess the first question is: How does it sound to your ears? You were saying there's an apparent lack of mid-bass. Is that corrected now?

 

[ddude003]

Maybe this is a dumb question and do you have any acoustic room treatments, absorbers or diffusers?

 

[dan711]

It definitely sounds better than any other time recently. Mid-bass is back with authority. The anemic sound when watching tv programs has been replaced with a fuller sound for sure. I still want to work on cleaning up that peak @ 55 hz and on up through 120 hz. I want that mid-bass kick but don't want that one or two note constant overwhelming boom.

I guess the first question is: How does it sound to your ears? You were saying there's an apparent lack of mid-bass. Is that corrected now?

I do not have any room treatments besides the usual carpeted floor, some fabric window treatments and a large fabric covered sectional.

Maybe this is a dumb question and do you have any acoustic room treatments, absorbers or diffusers?

 

[Todd Anderson]

Well that's great news then! Your ears are way more important than the graphs . The problem becomes striving for ultimate perfection, which can be maddening at times. It's important to keep in mind that very few enthusiasts have achieved it!

Now, Dan, it's time to treat that room!

Tons of options - from the DIY route to going through a manufacturer such as GIK Acoustics. You can follow some general guidelines about treatment, or if you want to get super technical someone like @Matthew J Poes (who salivates over room acoustics) might have some tips on where you can start.

 

[Matthew J Poes]

Well that's great news then! Your ears are way more important than the graphs . The problem becomes striving for ultimate perfection, which can be maddening at times. It's important to keep in mind that very few enthusiasts have achieved it!

Now, Dan, it's time to treat that room!

Tons of options - from the DIY route to going through a manufacturer such as GIK Acoustics. You can follow some general guidelines about treatment, or if you want to get super technical someone like @Matthew J Poes (who salivates over room acoustics) might have some tips on where you can start.

Absolutely willing to help