Comments on: Reflection-Free Zone http://arqen.com Sound and gear for your dream studio. Meet the powerfully quiet Phantom DAW computer. Learn the DIY art of recording studio acoustics. Come check it out! Wed, 21 Dec 2022 22:54:00 +0000 hourly 1 https://wordpress.org/?v=4.2.38 By: Lee http://arqen.com/acoustics-101/reflection-free-zone/#comment-1380 Mon, 18 Oct 2021 20:27:00 +0000 http://arqen.com/?page_id=9579#comment-1380 The information you provided regarding the precedence effect and Haas effect is incorrect. The precedence effect is triggered with a delay time of 1.1ms or higher (lower boundary), depending on the type of source, with its upper boundary (echo threshold) being 35-50ms for speech or 80ms for orchestral music. You mentioned the image would shift if the reflection delay is below 15ms, but it wouldn’t as long as the precedence effect operates, in the delay time range between 1ms and the echo threshold, but you get image spread and colouration effects. In the article, the Haas effect and the precedence effect seem to be confused, as often found in other resources too. The Haas is about the relationship between the reflection delay and reflection level in terms of the precedence effect. e.g. at around 20ms, the precedence effect is still triggered even if the reflection is 11dB or so louder than the direct sound, above which echo is perceived. This level threshold changes with delay time.

]]> By: Jason Lees http://arqen.com/acoustics-101/reflection-free-zone/#comment-1243 Wed, 21 Aug 2019 02:07:00 +0000 http://arqen.com/?page_id=9579#comment-1243 Hang blanket on the wardrobe & soft curtains for the window…but that would just cover high & maybe some upper mid frequencies…which is still an improvement

]]> By: Mark Samuels http://arqen.com/acoustics-101/reflection-free-zone/#comment-1211 Sat, 05 Jan 2019 05:47:00 +0000 http://arqen.com/?page_id=9579#comment-1211 Hi, I have mirrored wardrobes on ones side and window on the other. What can I do about these?

]]> By: James Sandwell http://arqen.com/acoustics-101/reflection-free-zone/#comment-1076 Tue, 14 Feb 2017 13:03:00 +0000 http://arqen.com/?page_id=9579#comment-1076 Hello, a lot of really great information here!
There is something bugging me though. The EBU / ITU criteria is the best thing we have for general specifications that should be met for a professional control room. But can we assume their standards are probably slightly lax for full range audio as they primarily deal with the human voice (is that fair to say?). As far as i’m aware, with ITD we can localise sound well down to 200Hz or so extremely well… I know it is very hard to get information on monitor polar responses but can we assume that most are omni-directional below 500Hz? Should we therefore not be treating the front wall with absorption? Sorry if the tone of my question comes off as rude. I have been reading about acoustics for the last year now and the general consensus seems to be that treating early reflections down to 1kHz is acceptable and i’m really frustrated! Am i missing something?
Thanks a lot,
James.

]]> By: Tim Perry http://arqen.com/acoustics-101/reflection-free-zone/#comment-1002 Sun, 12 Jun 2016 01:48:00 +0000 http://arqen.com/?page_id=9579#comment-1002 Hi John. Glad you like it! Looks like this message slipped through my radar.

Yes, that’s right. Your ISD gap is about 12 ms. Reflection points for surround speakers are not as critical. I’ve used both absorption and diffusion on the front wall to treat them, but your choice depends on the overall response and goals for the room. In general, diffusers or hybrid absorber-diffusers on the front wall are a safe bet.

If space and budget is no concern, one solution that works well for surround sound (and stereo) mixing is a room with deep bass absorption on all walls + ceiling, with hybrid absorption-diffusion overtop. Like this: http://www.myroom-acoustics.com/hosted/myroom-acoustics/MyRoom_Design-white_paper.pdf

Whether or not you should toe in your surround speakers would depend on their dispersion characteristics. Your best bet is to consult the speaker manufacturer, and you can also measure the resulting response using Room EQ Wizard. If you want to get scientific with speaker placement, the best source of information I know is the book Sound Reproduction: The Acoustics and Psychoacoustics of Loudspeakers and Rooms: http://www.amazon.com/gp/product/0240520092/ref=as_li_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=0240520092&linkCode=as2&tag=arqen-20&linkId=3AJPDV6NPHR6V3IT

Cheers,
Tim

]]> By: John http://arqen.com/acoustics-101/reflection-free-zone/#comment-889 Fri, 16 Oct 2015 01:20:00 +0000 http://arqen.com/?page_id=9579#comment-889 Great writeup! I appreciate all the great info. My room is 13x18x8. I use a 7.1 setup. I sit 6 ft 10 inches from the back wall. I am going to treat the first reflections that need to be treated based on the ITU standard for the side walls and ceiling using absorption. I am going to treat the rear wall with diffusion. This should create a ISD gap of about 12 ms. Correct? Again, using the the ITU standard, would I treat my surround speakers’ first reflection points? If so, would I use diffusion or absorption? Also, should my surround speakers be towed in like my fronts to get the flattest response or be straight forward? Thanks for your time.

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