Comments on: Listening-Room Reflections and the Energy-Time Curve https://www.hifizine.com/2011/12/listening-room-reflections-and-the-energy-time-curve/ The enthusiast's audio webzine Wed, 06 Mar 2024 19:37:30 +0000 hourly 1 https://wordpress.org/?v=4.9.25 By: John https://www.hifizine.com/2011/12/listening-room-reflections-and-the-energy-time-curve/comment-page-1/#comment-96793 Wed, 19 Oct 2016 17:11:49 +0000 http://www.hifizine.com/?p=3773#comment-96793 Thanks for the well written article and examples. Armed with your article and REW I compared the decay times as you outlined and found that my room exhibits the same decay time characteristics as figure 5. No small surprise then that the room sounds “dry” and like your example room in figure 5 it also has thick fibrous wallpaper on all walls and carpet.
So I’m curious as to what you might suggest for improvements and if there were changes made to the example room and how they worked out?

]]> By: Tord Johansson https://www.hifizine.com/2011/12/listening-room-reflections-and-the-energy-time-curve/comment-page-1/#comment-78907 Mon, 26 Oct 2015 19:38:31 +0000 http://www.hifizine.com/?p=3773#comment-78907 I got interested in the listening rooms effect on the acoustic “behaviour” of loudspeakers for two reasons. 1) I built a three way speaker system with very good drivers (SS 18W/4741, SS 3004/660000) and two subwoofers, active crossover and separate amplifiers . I calibrated the SPL with help of measurements from a Omnimic, both regarding atenuation of the drivers and also adjusting for unevenness in “local soundpreasure” over the frequencies. I got a very good sound. But measurements also showed huge dips in SPL, at 50-70 Hz. The problem was/is room reflections. I moved the subwoofers into the room and that solved some of the problems.
2) I just inherited two loudspeakers Carlsson OA52 with passive crossover. I set them up with my amplifier and “fired up”. I got amazed! – The “stereo room picture” was enormously better with much better bredth, depth and a more accurate timbre of voices and instruments. One explanation probably is the way the speaker enclosures are designed. They supress unwanted reflected sound from the speaker drivers (wich usually has another frequency spectrum compared to the direct sound thus offsetting true high fidelity, beside the ordinary interference that affect the SPL).

Conventional speakers are usually designed as boxes, with no “facilities” for reduction of unwanted sound emmission from the drivers that causes disturbing reflexes in ordinary rooms. Usually what is dicussed when testing those speakers is SPL-evennes and distortion in acousticly dead rooms. I would like to know the opinions on how to design speaker enclosures that also take into account, and optimizes, speakers for use in ordinary living room – without having to refurbish/dampening the room. Would apprechiate views on how to solve this issue!

]]> By: jim goulding https://www.hifizine.com/2011/12/listening-room-reflections-and-the-energy-time-curve/comment-page-1/#comment-2302 Sat, 25 May 2013 15:51:48 +0000 http://www.hifizine.com/?p=3773#comment-2302 For this reason, loudspeaker position should be out from the walls appreciably so the time and intrusion of reflected waveforms is made less significant. There is true ambient information contained in recordings made on location that we should want to preserve and speaker location with respect for the earliest arrival of reflected waveforms in room does help, significantly. I wouldn’t get obsessive about this if I were you, just do what I’ve suggested and add some aftermarket product for the absorption and/or diffusion of waveforms at the first reflection points and have the usher show you to your seat. Cheers.

]]> By: Alex https://www.hifizine.com/2011/12/listening-room-reflections-and-the-energy-time-curve/comment-page-1/#comment-1633 Fri, 01 Mar 2013 08:58:37 +0000 http://www.hifizine.com/?p=3773#comment-1633 Great, thanks!!

]]> By: John Reekie https://www.hifizine.com/2011/12/listening-room-reflections-and-the-energy-time-curve/comment-page-1/#comment-1589 Fri, 22 Feb 2013 14:42:33 +0000 http://www.hifizine.com/?p=3773#comment-1589 Hi Alex, per Nyal’s reply above, it can be done in Room EQ Wizard (REW) and ARTA. In REW, use the Filtered IR window and select the filter in the lower left corner of the window.

]]> By: Alex https://www.hifizine.com/2011/12/listening-room-reflections-and-the-energy-time-curve/comment-page-1/#comment-1584 Thu, 21 Feb 2013 22:13:18 +0000 http://www.hifizine.com/?p=3773#comment-1584 Great article!! One question: How do i make band filtered etc meassurement?

]]> By: Nyal Mellor https://www.hifizine.com/2011/12/listening-room-reflections-and-the-energy-time-curve/comment-page-1/#comment-1069 Fri, 13 Apr 2012 18:20:42 +0000 http://www.hifizine.com/?p=3773#comment-1069 Hi Nathan, a couple of things:

– the presence of individual high gain reflections (Fig 2 has some major spikes visible on the ETC)
– the non-smooth decay (Fig 2 ETC goes down, up, down, up)

Hope that helps!

Nyal / Acoustic Frontiers

]]> By: Nathan https://www.hifizine.com/2011/12/listening-room-reflections-and-the-energy-time-curve/comment-page-1/#comment-1030 Sat, 24 Mar 2012 04:11:10 +0000 http://www.hifizine.com/?p=3773#comment-1030 Hi

What makes figure one better than figure two? It’s not clear what is consistent or not. They both appear mighty jaggy. Perhaps you could circle the problems in one?

]]> By: Nyal Mellor https://www.hifizine.com/2011/12/listening-room-reflections-and-the-energy-time-curve/comment-page-1/#comment-1011 Mon, 13 Feb 2012 18:23:19 +0000 http://www.hifizine.com/?p=3773#comment-1011 Hi John

Thanks for your comment! Room EQ Wizard and ARTA have the band filtered ETCs. All the graphs in this article were done in Room EQ Wizard.

Nyal

]]> By: John Boone https://www.hifizine.com/2011/12/listening-room-reflections-and-the-energy-time-curve/comment-page-1/#comment-1010 Thu, 09 Feb 2012 17:09:17 +0000 http://www.hifizine.com/?p=3773#comment-1010 Good article!

You have certainly explained the usefulness of octave-filtered energy-time curves.

Do many(or any) of the available measurement software packages allow for octave-filtered ETCs?

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