1. Join Now

    AVForums.com uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

2 Subs - In or out of phase????

Discussion in 'Subwoofers' started by dealmaker, Apr 20, 2001.

  1. dealmaker

    dealmaker
    Standard Member

    Joined:
    Feb 21, 2001
    Messages:
    740
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    21
    Location:
    nearly in Scotland!
    Ratings:
    +1
    About to add a second REL sub to my Home Theatre room - is the recommended approach to run the two subs out of phase i.e one set at 0 degrees - and one at 180 degrees or IN phase????

    [ 20-04-2001: Message edited by: dealmaker ]
     
  2. slingshot

    slingshot
    Active Member

    Joined:
    Jan 31, 2001
    Messages:
    1,212
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    48
    Location:
    UK
    Ratings:
    +32
    I don't think there's any hard and fast rule, because it will depend where your placing the 2 subs.

    If both subs are at the front i.e. both next to the normal stereo speakers then you'd probably get better results with the both on the same phase. If one's at the front and one's at the back then they'd probably be better out of phase with each other (unless your trying to cancel out some boominess with the sub at the rear).

    I'll have a look see if I've got any more info lying around about setting up two subs.

    Slingshot
     
  3. Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    I too run a multiple sub set-up (2 Rel Storms and a Monitor Audio ASW100) and have quite recently spent alot of time playing with them. I recieved a copy of Strykes Basszone test cd from :www.stryke.com/ which has has reached "absolutely essential" status in the short time i have had it, for about £12 it is a fantastic tool for the more discerning sub-sonics enthusiast. In short it contains some 100 tracks containing test tones (most importantly the ones in the 10-25hz range) used with a sound pressure meter this allows you (although it's quite obvious by ear)know petty accurately where the acoustic "peaks and troughs" are (if you are using a Tandy/realistic SPM then certain correction values should be applied). However what it showed and i was quite surprised was that when i ran the subs in (or as near as dammit) phase there was (this is how i have run it for some time) tremendous presence in the 32-50hz range but rolled off drastically below that. Whe
    i ran them completely out (the 2 Rel's at 0 and 180 degree's and the MA at about 110 degree's) the overly inflated 32-50hz smoothed right out and there was presence down to 20hz and in my opinion really sounds quite cultured by comparison and has had me on a dvd revisit extravaganza of late. Alot of people would probably say "oh i would of found that out anyway" but just the abilily to play a known quantity frequency for a length of time and listen to the relation of your actions on other parts of the spectrum is just great. If only i had this years ago, a serious serious must for all multiple sub users (and anyone else really).

    Regards

    SteveEX
     
  4. Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    I would like to add that personally i believe the advice "the sub is in phase when the output is at it's fullest" is somewhat crude and vey "rule of thumb" as i have stated above phase relations at certain frequencies will/may not be uniform for others. The above disc gives you the opportunity to evaluate performance/acoustic variants and phase relationship's across the lower frequency spectrum rather than using a dvd scene or processor test tone of unknown quantity and basing your subs set-up on this alone. I have been into HiFi for some 15 or so years now and am frankly no stranger to (sub-sonic) wavelength propagation and related area's and frankly this simple disc would of saved me years of experimentation (perhaps not a good thing) i now am satisfied that i am getting the peak performance from my low end.
    For the record i know (and own) several of these test type records (vinyl) which were all the rage a long time back (anyone recall?) but a cd's inherently high s/n ratio, stability and below percievable distortion attributes make life so EEAASSYY..
    Now if only Dolby and DTS would offer something similar......

    Hope this helps

    Regards

    SteveEX
     
  5. Phil Hinton

    Phil Hinton
    Editor Staff Member

    Joined:
    Jan 18, 2001
    Messages:
    9,760
    Products Owned:
    2
    Products Wanted:
    0
    Trophy Points:
    166
    Location:
    AVForums
    Ratings:
    +7,140
    Steve,
    Dts do have such a cd and i own a copy of it.It does the usual LCRRSLS sub tones,but more importantly it has two sweeps from 15hz to 100.It also has 5 music tracks(seal's prayer for the dying,1812 overture,alan parsons so far away,shoeless joe the bet,and telarcs surround madness).
    E-mail fionahinton@dtsonline and request a copy,it's called DTS technology demonstration and set up.
    Cheers.
     
  6. Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    Thanks for the info but i was aware of this disc and while it does contain sweeps, i meant set frequency test tones (i.e 10,12.5,15,17.5hz etc etc) all available at 30 second or so runs as on the Stryke test cd. This would effectively by-pass the bass management implementation of the processor if it was a dedicated LFE track (DD/DTS). Given that the Stryke test cd is just that a "cd" you (or rather I) have to select small for the mains, which mine are most certainly not (no roll off until about 28hz) and leave the power amps off so you are hearing the sub's output only. I say this because in my experience, a sub's crossover can and will interfere or interact with with the processor's crossover if the two are set quite (crossover) close to each other which manifests itself in phase anomilies. If your processor has variable crossover settings for all speakers then this adds yet another factor.
    There is a general consensus that you should simply open up your sub's crossover to it's highest setting to avoid this interaction (and yet there is also a common acceptance that most smallish/medium rooms exhibit a 40-50hz bloom, in my room this proved to be as much as 10-12db a percieved 3 to 4 times the output which was quite unacceptable and tiresome to listen to) which was how i first used my set-up but the output was so aggressive that it became offensive to anyone in or near the house. Finally i have settled on all sub's run on high level level inputs, out of phase with each other, Lfe set to main and Sub with sub crossovers set to around 30hz (phase relationship with the mains becomes far less problematic than phase relationships betwwen the sub' themselves)
    A bit long winded i know but sub-sonics is and IMHO has always been the most complex factor to get right and is ALSO the main factor in making the difference between a good and a great sounding set-up

    Regards

    SteveEX
     
  7. Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    Hi There

    All the above posts accepted, as you are getting a second REL that has 0Deg or 180Deg phase switching, surely it will be a case of switching the phase controls to one or other position for the best result.

    If your not happy with the results then you will have a positioning problem. It seems to me the phase problem will be solved easily, hopefully so will the positioning.

    Try this one!!. When you get the second REL Wire them up next to each other and turn one phase switch so that one sub is out of phase with the other, the bass dissapears completely. No real point to the exercise but Interesting all the same. (Done this a number of times at work, little things hey!)

    Good luck with the system, extra sub should have things rocking.
     
  8. 69COU

    69COU
    Active Member

    Joined:
    Feb 8, 2004
    Messages:
    696
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    31
    Ratings:
    +55
    Very old post however any idea if you can still get the test CD mentioned.

    I have looked up www.stryke.com/basszone/index.html with no luck?
     
  9. Jase

    Jase
    Well-known Member

    Joined:
    Mar 16, 2001
    Messages:
    9,469
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    136
    Location:
    South Coast
    Ratings:
    +893
    Has to be a record for a thread resurrection...nearly 16 years. :eek:

    Is the thread below of any use to you?

    Subwoofer and full range test tones

    Alternatively, if you search for 'subwoofer test tones' or 'bass tone generator' a few sites pop up with downloadable tones etc.
     
  10. duffus

    duffus
    Active Member

    Joined:
    May 7, 2016
    Messages:
    196
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    28
    Location:
    Norway
    Ratings:
    +75
    There are also quite a few test tracks on Spotify that I've been using.

    Just do a quick search for "test tones"/"subwoofer test" or something similar.
     

Share This Page

Loading...