nzlowie Posted March 29, 2020 Share Posted March 29, 2020 Hi all, hope everyone is handling the lock downs and keeping their distance. Crazy times..... Time for audio though! In a previous post I was looking for idea's for my new room that I think sounds harsh, I found that installing absorption on the angle section of the roof helped a lot. Last night I ran some REW sweeps to see if they showed anything, I couldn't see much apart from maybe needing more bass trapping. I thought I'd throw it out to the team and see if you guys have any idea's on interpreting what these sweeps show and how to tune a room based on REW . Having REW sweeps doesn't really mean anything unless you know how to read them! Link to comment Share on other sites More sharing options...
WasM Posted March 29, 2020 Share Posted March 29, 2020 Is there a reason you started the measurement sweep from 50Hz and up? would be helpful to understand what the measurement sweep consisted of (L+R with or without sub) and what you are trying to achieve. If its flat curve response with good decay you have a decent waterfall plot from 160Hz and up. From there down you need more work. Link to comment Share on other sites More sharing options...
nzlowie Posted March 29, 2020 Author Share Posted March 29, 2020 This is left at my listening spot, didn't go right down as my main concern is in the upper frequencies. Room sounds harsh on some music that sounded ok in my previous room. But really it's how to interpret REW info and what to do based on what they show. Link to comment Share on other sites More sharing options...
frednork Posted March 29, 2020 Share Posted March 29, 2020 Nothing looks terribly amiss to me however the "room curve" is pretty flat. This is largely a matter of taste and how the room (and system) performs. Do you have a measurement of the previous room to compare? If not, are you able, as an initial test reduce everything above 600Hz by 3db (perhaps using a high shelf function) and see how that sounds. Link to comment Share on other sites More sharing options...
nzlowie Posted March 29, 2020 Author Share Posted March 29, 2020 Thanks Fred, will give it a try. So the increasing HF decay rate wouldn't be anything to do with it? I mean its not falling as fast as the mid range. I can understand LF hanging around in the room for longer but HF? Does this just show I need more absorption? Link to comment Share on other sites More sharing options...
davewantsmoore Posted March 29, 2020 Share Posted March 29, 2020 19 hours ago, nzlowie said: I thought I'd throw it out to the team and see if you guys have any idea's on interpreting what these sweeps show Your waterfall dosn't show anything particularly intersting ... and when they do, it is only in the bass (so it's not going to tell you about "harsh" sound). The dB scale is HUGE, and the waterfall makes it hard to read. Post just the frequency response, with a decent resolution. It looks like, what we will see, is that the level from 200ish to 2000ish is sloping upwards.... and that will be the culprit. Link to comment Share on other sites More sharing options...
davewantsmoore Posted March 29, 2020 Share Posted March 29, 2020 4 hours ago, nzlowie said: So the increasing HF decay rate wouldn't be anything to do with it? I mean its not falling as fast as the mid range. No, this is just noise in your measurement. If you check a sweep of your ambient noise in your room, you will then be able to tell what part of this waterfall data is valid. ... but don't even bother. Stop looking at the waterfall, and just look at the FR. 1 Link to comment Share on other sites More sharing options...
frednork Posted March 30, 2020 Share Posted March 30, 2020 (edited) @davewantsmoore has beaten me to it, the shape of the bottom of the waterfall is typical and not an indicator of anything much. And I was also going to also ask if you could post a frequency response curve as found in the All SPL tab perhaps with 1/12 smoothing which might show more info. Also distortion graph may be useful. So, what he said !! Edited March 30, 2020 by frednork Link to comment Share on other sites More sharing options...
nzlowie Posted March 30, 2020 Author Share Posted March 30, 2020 Cheers guys, how do I capture ambient room noise in REW? Room is pretty quiet.... Do we want to look at FR from my listening spot or at say 1500mm (this looks better!) Link to comment Share on other sites More sharing options...
frednork Posted March 30, 2020 Share Posted March 30, 2020 (edited) 45 minutes ago, nzlowie said: Cheers guys, how do I capture ambient room noise in REW? Room is pretty quiet.... Do we want to look at FR from my listening spot or at say 1500mm (this looks better!) You can do an RTA (real time analysis) measurement but probably unlikely to help as far as harshness goes . Here is a tutorial , just use no noise instead of pink noise and keep quiet!! https://community.roonlabs.com/t/a-guide-how-to-do-room-correction-and-use-it-in-roon/23800 DOnt worry about the making eq's and roon bit Where you listen from is the place to measure as it may measure better elsewhere but no use if you are not there. There may be a reason to do a nearfield measurement of the speakers but lets see what the LP shows. The other issue is that individual points in space may not give an as accurate representation of how it "sounds overall" and multiple measurements might be better to use in the long run . Even if you post the sweep you already did or others from the LP is ok as a start Edited March 30, 2020 by frednork Link to comment Share on other sites More sharing options...
davewantsmoore Posted March 30, 2020 Share Posted March 30, 2020 2 hours ago, nzlowie said: Do we want to look at FR from my listening spot or at say 1500mm (this looks better!) Why not both?! .... but if anything, the listening spot. Link to comment Share on other sites More sharing options...
davewantsmoore Posted March 30, 2020 Share Posted March 30, 2020 2 hours ago, nzlowie said: Cheers guys, how do I capture ambient room noise in REW? Turn your amplifiers off, and run a sweep. Link to comment Share on other sites More sharing options...
davewantsmoore Posted March 30, 2020 Share Posted March 30, 2020 On 29/03/2020 at 2:13 PM, nzlowie said: how to tune a room based on REW It is only relevant for < 300Hz.... above this the room is somewhat overrated, unless you have big problems. To diagnose your room > 300Hz, it would be better to post a photo of them room, rather than the measured response. That being said, I would bet my house that your don't have a "room issue". I can see the frequency response is wonky.... and so you will have "something about the sound" to report (harsh, flat, bloated, hollow, exciting, boring....or something.) Above about 300hz, the speaker response itself is the most important.... ie. how is your frequency response on your listening axis .... and how is the frequency response at other angles (which is another way to to say " do the crossovers sum well?") Link to comment Share on other sites More sharing options...
frednork Posted March 30, 2020 Share Posted March 30, 2020 41 minutes ago, davewantsmoore said: Turn your amplifiers off, and run a sweep. Ha ha, yes. why didnt I think of that? Link to comment Share on other sites More sharing options...
nzlowie Posted March 30, 2020 Author Share Posted March 30, 2020 Yea you go, noise floor, Distortion and FR at listening spot. Yes noise floor shows an increase as FR increases which might contribute to the waterfall i posted earlier. FR shows reasonably flat from around 350 to 7 khz so might look at rolling it off after 600hz as Fred suggested. Link to comment Share on other sites More sharing options...
frednork Posted March 30, 2020 Share Posted March 30, 2020 Nothing looks terrible above 100Hz so no obvious cause for harshness. How does this room compare with the other in terms of absorption (either placed specifically or incidental due to carpet or building materials ie concrete floor vs wooden etc)?. If you are running roon or something that accepts a convolution filter you can follow the tutorial I posted earlier and get REW to create a stereo filter for you. The trick with that is getting the room curve right. It is surprising how quickly it can make a big positive difference tho for not huge effort and no bucks. Link to comment Share on other sites More sharing options...
nzlowie Posted March 30, 2020 Author Share Posted March 30, 2020 Current room is completely different construction and shape. I'm running Audio Optimiser so it was easy to dial in some cut as suggested and sounds better, will play some more. Stupid me, i forgot all about room curve even though I'd look into it when I first started to play with Minidsp. Came back to me as soon as you mentioned it. Went with -2db to start as I don't wan to loose too much up top, my old ears have already lost a fair bit! And..... some albums sound magic as it is - was. I was paranoid about my room as I still have a strange high pitched echo when i do the clap test, thats the main reason i was looking for advise / thoughts on room acoustics. Again, appreciate your thoughts. Link to comment Share on other sites More sharing options...
frednork Posted March 30, 2020 Share Posted March 30, 2020 Ahh ok this is the room with the pitched ceiling. you might need to treat that a bit more to get rid of that flutter echo. I had one as well and was very annoyed by it. That might be all that needs to happen. Link to comment Share on other sites More sharing options...
davewantsmoore Posted March 30, 2020 Share Posted March 30, 2020 (edited) 16 hours ago, nzlowie said: increase as FR increases which might contribute to the waterfall i posted earlier. Not might. Quote FR shows reasonably flat from around .... Your dB scale is huge, making it hard to read. Zoom in. Apply more smoothing. Try 1/3 octave, and zoom in as far as you can without cutting off any data. Limit to 100Hz to 10khz (which will let you zoom in further). Juts rolling off above 600 doesn't seem like the right answer to me..... sure, you might like it more, you migh like it less.... but you'll just be chasing your tail. What are the XO in the speaker? How much to the drivers overlap? Edited March 30, 2020 by davewantsmoore Link to comment Share on other sites More sharing options...
davewantsmoore Posted March 30, 2020 Share Posted March 30, 2020 15 hours ago, frednork said: Nothing looks terrible above 100Hz so no obvious cause for harshness. I've perhaps slightly exaggerated my red line ..... but having 1-2Khz some dB generally louder than 3-600Hz will make things sounds quite "bright", and "not-rich". The thing to keep in mind is this is just one measurement axis. If there are crossovers anywhere in this range, and these crossover don't sum well ..... then what we'll see at other measurement axis, is dips..... once we add up the entire power, what it may show is there is a whole bunch of power missing in the 300-600ish range. Link to comment Share on other sites More sharing options...
davewantsmoore Posted March 30, 2020 Share Posted March 30, 2020 15 hours ago, nzlowie said: I was paranoid about my room as I still have a strange high pitched echo when i do the clap test You may want to try some more absorbtion in the room .... try it "extreme" and "ghetto"..... bring in a matteresses, blankets, doonas, soft furniture, etc. etc. ..... and see if majorly changing the abosrbtion affects what you're noticing when clap. Getting the FR issues straightened out though is the most important .... and the room will potentially just excesserbate any SQ issues caused by them.. Link to comment Share on other sites More sharing options...
nzlowie Posted March 31, 2020 Author Share Posted March 31, 2020 Thanks for your input guys its been a really big help. I was blaming the room for everything as the speakers sounded wonderful in my previous room, seems the room wasn't fully to blame. More the interaction between both room and speakers. Tweaked the FR a little, only 1-2 db here and there and made a nice improvement, happy again! Sounding absolutely beautiful. Time to stop overthinking and just enjoy the music. Once again thanks for your thoughts / advise. 2 Link to comment Share on other sites More sharing options...
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