etc6849 Posted March 6, 2015 Author Share Posted March 6, 2015 It is interesting that is uses Audyssey. Is there a difference between it and the MultiEQ XT32 chip inside my preamp? I'm using a Marantz AV8801 with the Audyssey pro kit. btw, there is also IKMultimedia ARC2 DRC system which works fantastic. it's a package with a calibrated mic and two parts of software. one for measuring and a VST plugin which works in sound mixing editors. but it also works in players like Foobar2000 and Jriver. it's 300USD. Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted March 6, 2015 Share Posted March 6, 2015 I would think the Auddysee Pro is a little better from what I have read. I only used some of the older version of Auddysee and only for a short while. Quote Link to comment Share on other sites More sharing options...
mark1101 Posted March 6, 2015 Share Posted March 6, 2015 The recording should already have the cymbals dancing off the ceiling (if it was recorded in a live room), so what's the point of having my room compound this? Are we not trying to reproduce what the audio engineer heard? Some engineers use headphones any ways, so you can bet the material already sounds the way it should. More clarity and better imaging is what I like about room treatments. I really don't see that as a bad thing. I also don't think my room is too dead, and I honestly think it sounds great. You should have the trailing edge of cymbals dancing off the ceiling. I was just trying to understand how you determined that the amount, and placement of treatments is correct............and that the particular response on your room measurement is "right". It simply looked dead to me (the second waterfall plot).........like an anechoic chamber with no decay time, no reflected sound at all. Your room appears to have far too many treatments visually than one would expect to see. So I was just asking. I am no expert on room treatments and as I stated it is a real mystery to me, and I have all the measuring equipment and software like everyone else. At one point my room looked like yours. But over time I noticed if I was speaking as I walked into the room, my voice noticeably went "dead".........like I was walking into a chamber. Now I have a storage room full of these treatments and have opted for very few treatments and instead use "dispersion" which allows for a livelier room and a more live sound. I just sounds more "right" to me. The imaging is better now than when my room had overly reduced reflections, and a lot of absorption. We probably have slightly different preferences as well. I am not trying to have a theater.........my system is for music and 2 channel. As far as a studio goes I would imagine they are looking for a very dead room. They do not want any echo or reflected sound. They add that in artificially later. Most recordings are totally fake anyhow and have no "room" associated with them at all. Strictly recorded by "plugged in instruments". Quote Link to comment Share on other sites More sharing options...
etc6849 Posted March 7, 2015 Author Share Posted March 7, 2015 I think the waterfall plot looks dead because I should have used a 45dB range of data like GIK suggested. The plot should have all frequencies decay evenly, around 150-200 ms. I picked the locations to eliminate first reflections. No other reason beyond that. I can now easily hear the room that music was recorded in, where before it took some concentration to hear it. 95% or more of my music is not recorded in a dead/dry room. In nearly all studio recordings I have, you can hear that the room is not dead/dry. Same goes for movies too. Whether this is artificial reverb shouldn't matter as you are hearing what the audio engineer intended by not adding additional echo. After all, how many engineers use headphones to do their mastering? I admit I'm not an expert on the subject either -so that makes two of us! I don't see anything wrong at all with what you're doing if you like a little added echo. It is 100% personal preference. I'm just trying to get as close to possible to what was intended by the mastering engineer and movie director. Hopefully I'm not sacrificing imaging, but my system really images well in its current configuration. I was just trying to understand how you determined that the amount, and placement of treatments is correct............and that the particular response on your room measurement is "right". It simply looked dead to me (the second waterfall plot).........like an anechoic chamber with no decay time, no reflected sound at all. Your room appears to have far too many treatments visually than one would expect to see. So I was just asking. I am no expert on room treatments and as I stated it is a real mystery to me, and I have all the measuring equipment and software like everyone else. Quote Link to comment Share on other sites More sharing options...
etc6849 Posted March 15, 2015 Author Share Posted March 15, 2015 New bass traps are coming, I ordered them yesterday! I bought four of these monsters: http://www.gikacoustics.com/product/gik-acoustics-soffit-bass-trap/ And two of these to play with: http://www.gikacoustics.com/product/gik-acoustics-monster-bass-trap-flexrange-technology/ 2 Quote Link to comment Share on other sites More sharing options...
etc6849 Posted March 25, 2015 Author Share Posted March 25, 2015 The traps came today, but the monster bass traps are damaged, so I'm going to wait on re-calibrating until GIK let's me know what they want to do. Luckily, the soffit bass traps came in great condition (they are ~35-40lbs each), and have noticeably improved my bass at very low frequencies. These things are very rugged, but cost more than the monster bass traps (and aren't as pretty). I'm thinking about four more so I have eight in total. This seems ideal because when I move, I'd like to stack two in each corner (can't do that now due to my sloped ceiling). I haven't measured anything yet, but hopefully will tomorrow. Quote Link to comment Share on other sites More sharing options...
Max2 Posted March 25, 2015 Share Posted March 25, 2015 I overlooked panels for decades and then hung 10 2' X 4' panels in a 20' X 20' room a few months back. I put two on the ceiling as well. The sound stopped carrying and ringing. Echo's are gone and now I hear things with better clarity and less harsh tones that would pop up in some content. One weird thing is that you can sit is this room and it is very, very quiet now, but with everything off you now hear everything that goes on in the house, and Im upstairs above the garage. It made it so quiet I had to relocate a surveillance camera hard drive to my attic which I never noticed was so loud before. Quote Link to comment Share on other sites More sharing options...
etc6849 Posted April 5, 2015 Author Share Posted April 5, 2015 (edited) Chris and friends, I finally reran Audyssey XT32 pro this weekend after adding 4 GIK soffit bass traps and 2 GIK monster bass trap panels. These new panels were added after leaving the foam in my previous pictures, but relocating some of it within the room to make space for the bass traps. The results are very interesting. It looks like from a decay time perspective, my P39f's perform better at 40 Hz than when crossed over to the SVS PB13 ultras (when the preamp is in "pure direct" mode)?!? Could this be because the DSP of the subs are negatively affecting decay times or is it due to the driver size difference (13.5" versus 3 9" drivers)? How much better do you guys think the subs could perform if I run it in sealed mode (they are in 16Hz ported mode now)? Any thoughts on these new measurements compared to my old ones? Is it worth buying 4 more soffit bass traps (new REW file will be in next post)? I think overall, the subs seem better performing (in the important 60-80hz region) than running with just the mains and no Audyssey. I think the 60-80Hz improvement confirms the little extra punch I'm feeling now. Note that the response curves have no smoothing applied, but look pretty good I think. Edited April 5, 2015 by etc6849 Quote Link to comment Share on other sites More sharing options...
etc6849 Posted April 5, 2015 Author Share Posted April 5, 2015 Attached is the newer REW file with just the left P39f measurement (due to size). This is with "pure direct" enabled on the AVP, meaning no crossover and Audyssey XT32 is disabled. P39f only.zip Quote Link to comment Share on other sites More sharing options...
etc6849 Posted April 5, 2015 Author Share Posted April 5, 2015 Attached is the newer REW file with just the left P39f measurement (due to size), crossed at 80Hz to dual SVS PB13ultras. P39f crossed at 80Hz.zip Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted April 5, 2015 Share Posted April 5, 2015 (edited) I don't think it has anything to do with the driver size. I can't open up a few of the files to look at. Edited April 5, 2015 by derrickdj1 Quote Link to comment Share on other sites More sharing options...
etc6849 Posted April 5, 2015 Author Share Posted April 5, 2015 (edited) I'm not sure why the files wouldn't work unless the forum's software did something to them. They do need to be unzipped before REW will open them. Anyone else having issues? The more I think about it, the more I think 4 more soffit traps probably won't give me much better performance. No way are they going to do anything about the decays below 50 Hz. I promise to measure one with just a P39f with no crossover and Audyssey enabled. I'm in listening mode now It's really beyond words about the tactile and articulate bass I have now. I'm truly speechless about the sound. I'm running out of ways to squeeze performance out of my current room. I think a bigger room would definitely help below 40 Hz. Edited April 5, 2015 by etc6849 Quote Link to comment Share on other sites More sharing options...
etc6849 Posted April 5, 2015 Author Share Posted April 5, 2015 (edited) Here's a better "before" waterfall of the left P39f with Audyssey Pro and the SVS PB13 ultra's. I forgot what the crossover was at, but it'd be 60 or 80 Hz. The improvement is pretty neat to hear (and feel) first hand. AFTER: BEFORE: Edited April 5, 2015 by etc6849 Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted April 5, 2015 Share Posted April 5, 2015 I am not seeing a major change. What does the FR look like with the mains and sub? Are you using a bass boost down low? Is Auddysee setting the FR? I am sure others will chime in later and have some suggestions. Quote Link to comment Share on other sites More sharing options...
Chris A Posted April 5, 2015 Share Posted April 5, 2015 (edited) It looks like from a decay time perspective, my P39f's perform better at 40 Hz than when crossed over to the SVS PB13 ultras (when the preamp is in "pure direct" mode)?!?...Could this be because the DSP of the subs are negatively affecting decay times or is it due to the driver size difference (13.5" versus 3 9" drivers)? Based on the position of the fronts and the subs, I believe what is happening is that you are injecting more energy into the room at some "antinodes" with the subs on, which, according to the experts (Toole, Geddes, et al.) means that you're covering the room more evenly and completely with the subs on. How much better do you guys think the subs could perform if I run it in sealed mode (they are in 16Hz ported mode now)? Try it and look at all the REW plots after running Audyssey again. I think that you will find that the group delay "minimum phase" plot (found in the Controls menu--a button that you push to see the plot over the existing GD plot) will be a little flatter toward the bottom end--which is good--while the FR plots will likely roll off more rapidly on the bottom end, which isn't quite as good. I'd also recommend looking at the distortion plots for vented vs. sealed. You may see lower 3rd and higher harmonics in sealed mode, which is good. It looks like you have plenty of absorption (from the RT60 curves) and subwoofer/woofer gain (from the FR plots and the distortion plots). I bet that you can hear your breathing quite well in your listening chair with everything turned off. I think overall, the subs seem better performing (in the important 60-80hz region) than running with just the mains and no Audyssey. I think the 60-80Hz improvement confirms the little extra punch I'm feeling now. I agree. The subs are taking some of the load from the woofers in the Palladiums, which will reduce modulation distortion (which you can't see in the harmonic distortion plots). It's the modulation distortion--specifically the lower sidebands of the modulation products, which is so audible and objectionable. Breaking up the bottom octave or two using the separate sub drivers will lower the modulation distortion when playing real music and movie material. P.S. I had no problem opening the REW project files that you posted: it was those files that really gave me the insights that I commented on above. By the way, where was the microphone located for the measurements (x, y, z)? Looking good! Chris Edited April 5, 2015 by Chris A Quote Link to comment Share on other sites More sharing options...
etc6849 Posted April 5, 2015 Author Share Posted April 5, 2015 (edited) I bet that you can hear your breathing quite well in your listening chair with everything turned off. I definitely hear things clearer in the room versus untreated. I can hear every lip smack as well as air movement from well recorded vocals. It's the modulation distortion--specifically the lower sidebands of the modulation products, which is so audible and objectionable. Breaking up the bottom octave or two using the separate sub drivers will lower the modulation distortion when playing real music and movie material. This makes a lot of sense now that you mention it; thanks for this great insight! By the way, where was the microphone located for the measurements (x, y, z)? The mic was in the middle of where the main listeners head would be, right at ear level (seated in the money seat). I lowered the chair back all the way down so there should have been very little influence from it this time around. I think the first time the chair back was lowered only partway. You may see lower 3rd and higher harmonics in sealed mode, which is good. I just looked at the distortion graph. How does this compare to an excellent all horn loaded setup like yours? (which is what I really would like if I had the necessary space) Also, does REW have the capability to feed a complex signal (containing multiple frequencies), to measure IMD? I'm assuming there's some standard waveform that is used for IMD measurements? I want to experiment with sealed versus 16 Hz mode some more. I have some prior measurements from before the bass traps that I'm going to compare. I briefly tried sealed when I set up the room, but had read that this would take away a lot of the output capability (not that I'd ever use it), and this could be missed for LFE in movies. I'm going to post some old files here shortly. Happy Easter everyone! Edited April 5, 2015 by etc6849 Quote Link to comment Share on other sites More sharing options...
etc6849 Posted April 5, 2015 Author Share Posted April 5, 2015 (edited) Old sealed mode comparison (all measurements are following an Audyssey Pro calibration each time). What is interested is sealed mode causes an increase in THD at lower frequencies? Also, 15% THD @20Hz seems really high to me, especially given 95dB is no where near the full output of my system. Is this an accuracy issue with REW? All reviews of the SVS PB13 ultras showed very low THD when measured outside. The 3% THD of the mid-range is disappointing too (compared to this review of the P39f)? Edited April 5, 2015 by etc6849 Quote Link to comment Share on other sites More sharing options...
Chris A Posted April 5, 2015 Share Posted April 5, 2015 On 4/5/2015 at 4:31 PM, etc6849 said: Also, does REW have the capability to feed a complex signal (containing multiple frequencies), to measure IMD? I'm assuming there's some standard waveform that is used for IMD measurements? You can use the "dual tone generator" under the generator button at the top of the window, third from the left. This will only give you a feel for the magnitude of the distortion. Klippel uses the following procedures with the R&D and QA systems, now part of IEC 60268-5 Sound System Equipment, Part 5: Loudspeakers: AN 8 3D Intermodulation Distortion Measurement , AN 10 AM and FM Distortion in Speakers, and AN 16 Multi-tone Distortion Measurement and a link to a Klippel page discussing modulation distortion: https://www.klippel.de/know-how/measurements/nonlinear-distortion/intermodulation-distortion.html Quote Link to comment Share on other sites More sharing options...
etc6849 Posted April 5, 2015 Author Share Posted April 5, 2015 (edited) Thanks! I'll have to play with this later in the week. I also edited my previous post (aka added a bunch of questions ) with the sealed THD measurements just above your's; probably why you were typing your last post. You can use the "dual tone generator" under the generator button at the top of the window, third from the left. This will only give you a feel for the magnitude of the distortion. Edited April 5, 2015 by etc6849 Quote Link to comment Share on other sites More sharing options...
Chris A Posted April 5, 2015 Share Posted April 5, 2015 How does this compare to an excellent all horn loaded setup like yours? (which is what I really would like if I had the necessary space) Harmonic distortion is level dependent. I'll look around to see if I've got a plot that is close to the SPLs that you posted. Remember that horns and vented enclosures typically have about the same harmonic distortion levels, but vastly different modulation distortion levels. I haven't saved any two-tone test results, i.e., modulation distortion levels. Note that these are also very level dependent. Quote Link to comment Share on other sites More sharing options...
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