Max2 Posted October 22, 2014 Share Posted October 22, 2014 Just got rid of the nasty carpet in my "listening" room. Gonna do a large rug and some acoustic panels. Anyone have any tips or pointers they would like to share? I have slanted or dovetail walls which I don't know is a good thing or bad. I know its bad for the K's because I can't tuck them and gonna have to build false walls. Quote Link to comment Share on other sites More sharing options...
tnr Posted October 22, 2014 Share Posted October 22, 2014 (edited) A large area rug with at least 1/2" thick grey felt pad underneath will help big time. Edited October 23, 2014 by tnr 2 Quote Link to comment Share on other sites More sharing options...
babadono Posted October 22, 2014 Share Posted October 22, 2014 tnr, Just curious, why grey? Call me an a**hole if you need to Quote Link to comment Share on other sites More sharing options...
Chris A Posted October 22, 2014 Share Posted October 22, 2014 (edited) If you can run REW (free software) just one sweep using the microphone(s) in your computer, you can see the RT60 of the room by frequency. This will provide to you what you need to know: how much absorption and of what type/frequencies absorbed need to be in the room. False corners will be required, IMHO. But the question is, where do you expect to place the Khorns once you've got them in the false corners, and whether or not absorption on the slanted ceiling portions closest to the top of the Khorns will be needed. The area rug needs to extend to the front of each Khorn and out to at least 2-3 feet in front of each loudspeaker - and I'd recommend something that is fairly thick in your case. Chris Edited October 22, 2014 by Chris A 1 Quote Link to comment Share on other sites More sharing options...
Max2 Posted October 23, 2014 Author Share Posted October 23, 2014 tnr, Just curious, why grey? Call me an a**hole if you need to Thats the old color and I totally agree with you The back wall and sides are all the same even though my crap phone camera makes it look different, everything is dam near primer grey. If you can run REW (free software) just one sweep using the microphone(s) in your computer, you can see the RT60 of the room by frequency. This will provide to you what you need to know: how much absorption and of what type/frequencies absorbed need to be in the room. False corners will be required, IMHO. But the question is, where do you expect to place the Khorns once you've got them in the false corners, and whether or not absorption on the slanted ceiling portions closest to the top of the Khorns will be needed. The area rug needs to extend to the front of each Khorn and out to at least 2-3 feet in front of each loudspeaker - and I'd recommend something that is fairly thick in your case. Chris Thanks Chris. What is a decent mic that will plug into my laptop and won't break the bank? I have been listening to the K's about 10 inches from the rear wall, its really not as bad as I thought it would be, but Im sure its really ugly on paper. They will still remain as close to the corners as the walls will allow, but I will enjoy being able to seal them and toe them out where I have them now. Im really not a big fan of the 45 degree angle true corners put the speakers at. It puts the sweet spot too far forward for my ears. The width is a full 20 feet and my seat position is around 15 feet. Quote Link to comment Share on other sites More sharing options...
Ceptorman Posted October 23, 2014 Share Posted October 23, 2014 Those floors look nice though. 1 Quote Link to comment Share on other sites More sharing options...
muel Posted October 23, 2014 Share Posted October 23, 2014 I can't quite tell... is the ceiling symmetrical? If not that can cause a lot of imaging trouble. I wouldn't try to fight it for long and I'd put them on a wall that allows the speakers to be facing a direction that is symmetrical. Quote Link to comment Share on other sites More sharing options...
Max2 Posted October 23, 2014 Author Share Posted October 23, 2014 I can't quite tell... is the ceiling symmetrical? If not that can cause a lot of imaging trouble. I wouldn't try to fight it for long and I'd put them on a wall that allows the speakers to be facing a direction that is symmetrical. Yeah, the pics are really bad, there is just no lighting in the room. Hopefully I can find time soon to put some cans in. The room is square 20X20 other than a closet in the right rear that nabs 3' X 10' of the room and a dormer window next to it that extends about a foot deeper than the right wall, so it has an odd shape in the rear. Ceiling and slanted walls are square. I just needed about 4 inches to clear the K's, but the steep, old farmhouse style roof line wouldn't let happen. Im going to get a mic and run REW like Chris mentioned. I will get a before just to see how messed up it is with just bare floor too. Im running passives, so this might be a good thread just to see how well the panels, traps and a big rug will improve a hard floored oddball room. I'm hoping all the treatments will give better results than the old carpet alone. Quote Link to comment Share on other sites More sharing options...
tnr Posted October 23, 2014 Share Posted October 23, 2014 tnr, Just curious, why grey? Call me an a**hole if you need to I tried to paste a pic. By grey, I mean the soft felt stuff. That is the color it comes in. The important part is felt, as opposed to that crushed foam stuff. It holds up well. Comes in 1/8" to 1/2" thickness, maybe more. Quote Link to comment Share on other sites More sharing options...
Max2 Posted October 23, 2014 Author Share Posted October 23, 2014 (edited) tnr, Just curious, why grey? Call me an a**hole if you need to I tried to paste a pic. By grey, I mean the soft felt stuff. That is the color it comes in. The important part is felt, as opposed to that crushed foam stuff. It holds up well. Comes in 1/8" to 1/2" thickness, maybe more. Eh. I thought Babadono was talking about the wall color I guess you can tell i have had all of the color grey I want. I know the kind of felt you're talking about. We have it under a few other rugs. Pretty heavy stuff and should absorb well. I going to try and find a thick rug, preferably German Shepherd colored. This is similar to what we have. I does have the no- skid backing on one side. Edited October 23, 2014 by Max2 Quote Link to comment Share on other sites More sharing options...
Chris A Posted October 23, 2014 Share Posted October 23, 2014 (edited) Thanks Chris. What is a decent mic that will plug into my laptop and won't break the bank? You really don't have to have a calibrated microphone for running RT60 plots using REW - your laptop's built-in microphone will do that fairly well (I found this out the hard way while having trouble with a mixer and its software driver - I was inadvertently using the laptop's internal microphone(s) for sweeps, and it's not bad for this purpose (RT60). If you plan on using REW to do more than this one set of RT60 plots, this microphone is recommended by the Home Theater Shack folks for its simplicity, relatively low cost (for calibrated microphones), and pre-calibration: http://www.hometheatershack.com/forums/spl-meters-mics-calibration-sound-cards/63808-minidsp-umik-1-microphone.html If you've got an HDMI input to your preamp and HDMI output from your laptop (as I do), this is the simplest solution and overall the lowest cost--assuming that you don't already have a mixer that can provide phantom power to a calibrated XLR microphone. I'm using a Behringer ECM8000 with a small mixer, which also works very well, as long as you install the software drivers to the mixer that don't mess with REW at the same time (using Java, etc.). Edited October 23, 2014 by Chris A Quote Link to comment Share on other sites More sharing options...
Max2 Posted October 23, 2014 Author Share Posted October 23, 2014 Thanks Chris. What is a decent mic that will plug into my laptop and won't break the bank? You really don't have to have a calibrated microphone for running RT60 plots using REW - your laptop's built-in microphone will do that fairly well (I found this out the hard way while having trouble with a mixer and its software driver - I was inadvertently using the laptop's internal microphone(s) for sweeps, and it's not bad for this purpose (RT60). If you plan on using REW to do more than this one set of RT60 plots, this microphone is recommended by the Home Theater Shack folks for its simplicity, relatively low cost (for calibrated microphones), and pre-calibration: http://www.hometheatershack.com/forums/spl-meters-mics-calibration-sound-cards/63808-minidsp-umik-1-microphone.html If you've got an HDMI input to your preamp and HDMI output from your laptop (as I do), this is the simplest solution and overall the lowest cost--assuming that you don't already have a mixer that can provide phantom power to a calibrated XLR microphone. I'm using a Behringer ECM8000 with a small mixer, which also works very well, as long as you install the software drivers to the mixer that don't mess with REW at the same time (using Java, etc.). Thanks Chris. What is a decent mic that will plug into my laptop and won't break the bank? You really don't have to have a calibrated microphone for running RT60 plots using REW - your laptop's built-in microphone will do that fairly well (I found this out the hard way while having trouble with a mixer and its software driver - I was inadvertently using the laptop's internal microphone(s) for sweeps, and it's not bad for this purpose (RT60). If you plan on using REW to do more than this one set of RT60 plots, this microphone is recommended by the Home Theater Shack folks for its simplicity, relatively low cost (for calibrated microphones), and pre-calibration: http://www.hometheatershack.com/forums/spl-meters-mics-calibration-sound-cards/63808-minidsp-umik-1-microphone.html If you've got an HDMI input to your preamp and HDMI output from your laptop (as I do), this is the simplest solution and overall the lowest cost--assuming that you don't already have a mixer that can provide phantom power to a calibrated XLR microphone. I'm using a Behringer ECM8000 with a small mixer, which also works very well, as long as you install the software drivers to the mixer that don't mess with REW at the same time (using Java, etc.). I will break out the laptop and download REW. Maybe I have a mic on it and can get a reading tonight. Thanks Chris Quote Link to comment Share on other sites More sharing options...
Max2 Posted October 25, 2014 Author Share Posted October 25, 2014 Got REW loaded and it appears that I have a built in mic on my laptop. I have checked out the RTA playing music and a SineWave, but I don't know what Im doing here Quote Link to comment Share on other sites More sharing options...
Chris A Posted October 25, 2014 Share Posted October 25, 2014 If you've got an HDMI port out of your computer and a similar input on your preamp, you can run an upsweep. If you don't have those, you can connect the speaker out jack to your iPod-in port on your preamp (assuming that you've got one of those) and play an upsweep using the "Measure" button on the top left of the screen, which brings up a dialog box. If you ignore the calibration button for the moment, you can set the start, end, and length (I'd use 512K for a start). It should up-sweep and record - then you can select the "RT60" button after it stops to see the calculated response times by frequency for your room. There is a little "camera" button on the top left of plot window that will capture whatever's on the plot into a .jpg or .png image file that you can post on the forum thread for discussion--if you so choose, or that you can use yourself to determine how much damping you need to add in (or not) in your room. Chris Quote Link to comment Share on other sites More sharing options...
Max2 Posted October 26, 2014 Author Share Posted October 26, 2014 (edited) i can't get the signal out of my laptop vis hdmi. I have run a 20-20k sweep over my system via sound file after clicking the measure button, but I don't know what setting and all of that. I have calibrated the spell and the mic, but my graphs look strange. Lots of settings with this I don't know whats right or wrong settings wise, but here is what is showed. My recording fell short of the sine wave, so i am missing measurement from some of the top end of the sine. Edited October 26, 2014 by Max2 Quote Link to comment Share on other sites More sharing options...
Max2 Posted October 26, 2014 Author Share Posted October 26, 2014 (edited) I turned my sub off and turned the mic towards the speakers this time,once I found out where it was on the laptop. Laptop sitting on coffee table in front of listening position. Looks like Im gonna have to drop the mids down some more? Mids are -12 Tweeters are -3 Edited October 26, 2014 by Max2 Quote Link to comment Share on other sites More sharing options...
Chris A Posted October 26, 2014 Share Posted October 26, 2014 (edited) Some of this may be related to microphone calibration issues. I can say that if you punch the "RT60" button on the second menu bar from the center-top, you'll see something like this: Edited October 26, 2014 by Chris A Quote Link to comment Share on other sites More sharing options...
Chris A Posted October 26, 2014 Share Posted October 26, 2014 (edited) If those waterfall plots are the result of 20-20KHz sine sweeps, you may be needing a fair bit more broad band absorption in-room. With the vertical scale set to where it is, it's a bit difficult to see the decay. I'd reduce the vertical scale using the "limits" button to a max of 140 and a min of 20 dB, respectively Here is a waterfall plot of my room: Edited October 26, 2014 by Chris A Quote Link to comment Share on other sites More sharing options...
Max2 Posted October 26, 2014 Author Share Posted October 26, 2014 (edited) These are with a direct hdmi hookup through the laptop into my AVR with the Odyssey mic. This is the baseline with bare wood floor and no treatments, sub off and Odyssey off. Edited October 26, 2014 by Max2 Quote Link to comment Share on other sites More sharing options...
Chris A Posted October 26, 2014 Share Posted October 26, 2014 (edited) Anything above about 0.6 on the RT60 curves is probably too reverberant. In your case, this is mostly all above 1 KHz, so I'd recommend something on the floor (if you haven't already put an area rug down) and diffusion surfaces - like those funny looking cubic panels that are all different heights. Foam diffusion panels would be an idea. But we're probably talking a fair amount. You could also use tapestries and curtains - but we're talking something like the size of half the back wall. Try pinning up a comforter on two on the walls (perhaps side walls and between the Khorns on the front walls?) and re-running the RT60 curves to see what happens. I'd recommend more absorption rather than less if in doubt. Where are you taking your measurements relative to your listening position? Your coffee table in front of your listening position? Edited October 26, 2014 by Chris A Quote Link to comment Share on other sites More sharing options...
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