Page 4 of 4 FirstFirst 1234
Results 31 to 40 of 40

Thread: How far should speakers be placed away from walls to eliminate smearing from early reflections?

  1. #31
    Member Addicted to Best! NorthStar's Avatar
    Join Date
    Feb 2011
    Location
    Vancouver Island, B.C. Canada
    Posts
    16,793
    Quote Originally Posted by caesar View Post
    What is the ideal distance for speakers to be placed away from walls to eliminate the smearing effect of early reflections?

    In a perfect scenario, is the middle of the room the best place?

    Thank you
    As a general rule; one third of the room's length, and one fifth of the room's width.
    There are also other rules, like the lower woofer not the same distance from the floor and from the side wall, or multiples (2x, 3x).
    If the side walls are treated, the amount of toe-in is less dependent.
    http://www.soundfountain.com/amb/speaker.html
    http://www.westlakeaudio.com/Speaker...ers_in_th.html

    * The middle of the room is NOT the best place.

    http://www.audiophysic.com/aufstellung/regeln_e.html
    http://noaudiophile.com/speakercalc/
    http://www.tweakshop.com/Speaker%20Placement.html
    All the Very Best, - Bob --------- "And it stoned me to my soul" - Van Morrison --------- AudiophileAudition

  2. #32
    Member Addicted to Best! NorthStar's Avatar
    Join Date
    Feb 2011
    Location
    Vancouver Island, B.C. Canada
    Posts
    16,793
    Quote Originally Posted by caesar View Post
    Anyways, is there an ideal distance away from the walls for one not having to deal with this problem?
    http://www.tweakshop.com/Speaker%20Placement.html

    1. Room length:
    If your room is a rectangle, the speakers will ideally face the length of the room, so place your desk by the shortest wall.

    2.Think in thirds:
    Imagine dividing the length of your room by three. Your speakers will sit within the first third of the room and more than 1m from the side walls. We did say you needed some room...

    3. Speaker angles:
    Music is generally released in stereo, which means the sound is spread between the left and right speakers. Positioning the speakers at a 60-degree angle gives you the best 'stereo image' of these sounds. Dust off your old protractor and position the speakers 60 degrees apart. It can help to place a small marker at your listening position and work it out from there.

    4. Space from wall:
    If you really do have a huge room to work with, pull the speakers away from the wall. There's a zone between 1m and 2.2m that ideally you want to avoid. If you have a smaller room, try to leave as much space as you can between the wall and the speaker -- up to 1m -- and do not place them too close to the wall either as the bass doesn't play well.
    All the Very Best, - Bob --------- "And it stoned me to my soul" - Van Morrison --------- AudiophileAudition

  3. #33
    Member Addicted to Best! NorthStar's Avatar
    Join Date
    Feb 2011
    Location
    Vancouver Island, B.C. Canada
    Posts
    16,793
    Quote Originally Posted by caesar View Post
    Gentlemen, thank you for the great discussion.

    What is the reason that we do not see more placements of speakers on the long wall? Does that, generally, put the listener's head too close to the back wall? Or are other problems created that way?
    For average room's size (European* and North American) the long walls are generally prefered, for room breathing between the loudspeakers and the listener.
    But some people have no choice, or prefer large distance between the two speakers (wide soundstage).
    And if the room is 22 feet long by 19 feet wide, it is quite flexible...or on the long or on the narrower wall.

    * In Europe, generally they have smaller rooms.

    ** Post #21 (by micro) is excellent.

    *** I like speakers that have a smooth on and of axis dispersion response. ...Tight together following a directional pattern on the same wavelength.
    ...Say from zero to 60°
    All the Very Best, - Bob --------- "And it stoned me to my soul" - Van Morrison --------- AudiophileAudition

  4. #34
    [WBF Founding Member] audioguy's Avatar
    Join Date
    Apr 2010
    Location
    Near Atlanta, GA but not too near!
    Posts
    2,501
    My speakers are about 4.5 feet from side walls. I have had them closer in other rooms. Side wall first reflection diffussion, in my experience, makes the distance issue not too critical. Very easy to measure ... and hear. I use absorption for 2nd reflection point (opposite wall speaker). And like most of high end audio, personal preference still rules the day.
    “Audio as a hobby is dying, largely by its own hand. As far as the real world is concerned, high-end audio lost its credibility during the 1980s, when it flatly refused to submit to the kind of basic honesty controls (double-blind testing, for example) that had legitimized every other serious scientific endeavor since Pascal. [This refusal] is a source of endless derisive amusement among rational people and of perpetual embarrassment for me” - Gordon Holt

  5. #35
    WBF Technical Expert (Speaker & Acoustics) [Technical Expert] Mark Seaton's Avatar
    Join Date
    May 2010
    Location
    Chicago, IL
    Posts
    268
    I missed this thread previously, but thought I'd link to a nice summary Nyal Mellor has posted the matter here titled "Early Reflections 101."

    The key understanding is that both level and timing of a reflection matters. This explains why certain locations work just fine with one speaker, say a dipole/open baffle design, but less so with another. The relative level an spectral balance of the off axis energy can be very different between different speakers, hence reflections can come back at significantly different levels.

    While the article has many good points, here's an old graphic posted in it which should be digested a bit:
    Mark Seaton

    Seaton Sound, Inc.

  6. #36
    Some comments:

    Quote Originally Posted by caesar View Post
    What is the ideal distance for speakers to be placed away from walls to eliminate the smearing effect of early reflections?
    Smearing would imply that there is some kind of deterioration of timbre and/or image/sound stage. To the best of my knowledge the scientific literature does not provide the slightest shred of evidence that there is deterioration when playing music through 2-channel stereo systems in real rooms with multiple reflections and reverberation. If such negative effects occurred they would also occur with natural sound sources such as one’s wife/kids/dog/cat. Do they?


    Quote Originally Posted by JackD201 View Post
    Look up the Haas effect. There is a window where early reflections are BAD because in this short time range the brain mixes the direct and reflected sound. Outside of that the brain can distinguish direct from reflected and this is what is subject to preference.
    To begin with, Haas performed his experiments in open air, and used a single speaker as direct sound source and a single speaker for the lateral reflection, with each speaker at an angle of 45 degrees w.r.t the listening axis, and he further used speech. He found that within a window of 1-30 ms a broadening of the direct sound source was perceived, with the sound having more body, which was considered as positive by the listeners. A critical delay was defined as the delay where 50% of the listeners considered the reflection as disturbing, the average value being 44 ms. At a delay of 100 ms 100% of the listeners considered the reflection as disturbing.

    The delay at which the reflection is perceived as echo is called echo threshold. Its value depends on the type of signal and is between 5ms (clicks) and 80 ms (slow music).
    If the arrival times, like you suggest, are outside of the “problematic“ time window, you’re outside the window within which the precedence effect operates and will perceive reflections as echoes.


    Quote Originally Posted by Mark Seaton View Post
    While the article has many good points, here's an old graphic posted in it which should be digested a bit:
    This graph is equivalent to fig. 6.5 of Toole’s book, where the accompanying text says: “An illustration of the several audible effects that occur when a single lateral reflection is added to a direct sound, in an anechoic simulation similar to that shown in fig. 6.4b. All of these curves were determined using speech a signal “

    In all of these experiments a single speaker was used as direct sound source. No such data exist for 2-channel stereo in real conditions with multiple reflections+reverberation and music.

    Klaus
    Speakers: Klein + Hummel O500C, Electronics: Funk MTX preamp, Rane PS1 phonostage, Analog: Michell Gyrodec, SME 309, Shure V15VxMR, Digital: Tascam CD-RW4U, Tascam MD-801R

  7. #37
    Addicted to Best! sbo6's Avatar
    Join Date
    May 2014
    Location
    Round Rock, TX
    Posts
    465
    Quote Originally Posted by DaveC View Post
    Harman's research says sidewall reflections are desirable and give you a sense of spaciousness.
    I would agree. While you can get good results with absorption on sidewalls you won't know what you're missing unless you try diffusion, room dimensions permitting. Also, there is no perfect RT60.
    3x20A circuits | PS Audio PPP | Music PC (HQPlayer w/DEQ, Roon) | AQ Cinnamon CAT7 cable | HDPLex LPSU -> UltraCap LPS-1 -> Sonore Ultrarendu D->D | TotalDAC USB cable | Aqua Hifi Formula DAC | Oppo BDP103 transport | Purity Audio Silver Statement preamp | Wells Audio Innamorata amp | Usher BE20D speakers w/GR Res. upgrades | JL Audio F112 sub | JPS Labs SC3 ICs + Aluminata SCs | Stillpoints, BD cones | Custom birch rack | Fully treated + dedicated 2 channel room (absorption/diffusion)

  8. #38
    Addicted to Best! sbo6's Avatar
    Join Date
    May 2014
    Location
    Round Rock, TX
    Posts
    465
    Quote Originally Posted by caesar View Post
    What is the ideal distance for speakers to be placed away from walls to eliminate the smearing effect of early reflections?

    In a perfect scenario, is the middle of the room the best place?

    Thank you
    The cardas room setup guide is a good starting point which for cones = RW * .276 from woofer to sidewall and RW *.446 woofer to front wall (behind speaker).

    http://www.cardas.com/room_setup_main.php
    3x20A circuits | PS Audio PPP | Music PC (HQPlayer w/DEQ, Roon) | AQ Cinnamon CAT7 cable | HDPLex LPSU -> UltraCap LPS-1 -> Sonore Ultrarendu D->D | TotalDAC USB cable | Aqua Hifi Formula DAC | Oppo BDP103 transport | Purity Audio Silver Statement preamp | Wells Audio Innamorata amp | Usher BE20D speakers w/GR Res. upgrades | JL Audio F112 sub | JPS Labs SC3 ICs + Aluminata SCs | Stillpoints, BD cones | Custom birch rack | Fully treated + dedicated 2 channel room (absorption/diffusion)

  9. #39
    WBF Technical Expert (Speaker & Acoustics) [Technical Expert] Mark Seaton's Avatar
    Join Date
    May 2010
    Location
    Chicago, IL
    Posts
    268
    Quote Originally Posted by sbo6 View Post
    I would agree. While you can get good results with absorption on sidewalls you won't know what you're missing unless you try diffusion, room dimensions permitting. Also, there is no perfect RT60.
    Especially since RT60 doesn't really exist, nor have much application in domestic listening rooms. In general it only comes up when using rule of thumb calculations for % surface area coverage which again don't have much application in our listening spaces.
    Mark Seaton

    Seaton Sound, Inc.

  10. #40
    [WBF Founding Member] Addicted to Best! JackD201's Avatar
    Join Date
    Apr 2010
    Location
    Manila, Philippines
    Posts
    10,421
    Quote Originally Posted by Mark Seaton View Post
    Especially since RT60 doesn't really exist, nor have much application in domestic listening rooms. In general it only comes up when using rule of thumb calculations for % surface area coverage which again don't have much application in our listening spaces.
    I suppose that is more true of typical USA construction which uses a lot of gypsum, rock wall and have insulated gaps to boot. It's much more of a factor in places where codes require load bearing walls of poured concrete or older homes with heavy masonry. we end up building walls like yours on top of our own.

    My room is far from typical. I wish it was to be honest. The only place I could build a room big enough was to dig down. After a retaining wall sprung a leak during a long and heavy monsoon, I stripped off all the false walls and redid the walls and floors with shotcrete over space frame. Oh Lord. I remember being in the room inspecting the bare walls and floor when one of the workers came in and plopped down a full bucket of sealant. The thud went on and on. That was with the untouched ceiling where incidentally my bass traps are mounted. I could help but wonder how bad the decay times would be if even the concrete ceiling which is close to 80 square meters was bare.
    Disclosure of Industry Participation

    Co-Founder and Managing Director PureSound PH - Exclusive Distributor (Philippines only) of Lamm, Von Schweikert Audio, CH Precision, Light Harmonic, Valvet, Townshend, Critical Mass Systems, EERA, KR Audio, Ambience SS, TechDAS, Master Built

Page 4 of 4 FirstFirst 1234

Similar Threads

  1. Giya G3 close to side walls
    By murphys33 in forum Vivid Audio Forum
    Replies: 7
    Last Post: 07-08-2017, 11:41 PM
  2. Early Reflections 101
    By Nyal Mellor in forum Room Acoustics Forum
    Replies: 33
    Last Post: 10-30-2015, 09:27 PM
  3. Replies: 12
    Last Post: 07-21-2015, 09:15 PM
  4. Slanted walls
    By microstrip in forum Room Acoustics Forum
    Replies: 9
    Last Post: 07-17-2012, 07:31 PM
  5. Routing Cables Through Walls?
    By Matt193 in forum Audio Cable Forum
    Replies: 7
    Last Post: 04-08-2011, 11:42 AM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •