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Listening room...

Discussion in 'Audio Hardware' started by Claus, Jan 15, 2002.

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  1. jupiterboy

    jupiterboy Forum Residue

    Location:
    Buffalo, NY
    So it is down to what to put on the back wall, and how far into the room to move the listening position. I am leaning toward a pretty heavy, full-range bass trap with a built in scatter plate, and another bass trap in the front right corner, but I can’t get a grip on if to use a full range or more targeted trap in that position.
     
  2. tim185

    tim185 Forum Resident

    Location:
    Australia
    You want broad band full range treatment on your rear wall. Nothing that targets anything at this stage. Same goes for your corners, you want full range absorbtion there. Corners are critical, its a free lunch really, a 6db increase in absorbtion where two corners meet....so you want to go hard. Thats as thick as you possibly can. If you can get as thick as 8 inchs or more, then regular pink fluffy stuff will work better than than the usual rockwool batts, cheaper as well.
     
  3. jupiterboy

    jupiterboy Forum Residue

    Location:
    Buffalo, NY
    I want to get these two in place, then look at some ceiling corner traps that are very thick. That is where is build up is most noticeable. I will get at least one trap on a stand for starts, so I can reposition, and because the molding in this old house is so huge that no standard stuff will fit in the corners.
     
  4. tim185

    tim185 Forum Resident

    Location:
    Australia
    Yep ceiling corners often neglected but just as important as any other corners, including floor/wall though that ones a little impractical.
     
  5. jupiterboy

    jupiterboy Forum Residue

    Location:
    Buffalo, NY
    If that all goes well, then ceiling diffuser, but which one? That is going to take some study, and it will probably be a last step.
     
  6. tim185

    tim185 Forum Resident

    Location:
    Australia
    Yeah, Im not crazy about diffusion on the ceiling, but people have made it work. If you do, you will want 2D diffusors. I run 1D diffusers on my rear wall. You also dont want to sit too close to diffusers, these are all points worth researching.
     
  7. GreatTone

    GreatTone Forum Resident

    Location:
    Falls Church, VA
    I would love to treat my listening room, but as it's also a family room, it's not going to fly. My stereo is already too prominent (along with my albums). So I'm leaning toward getting some radial speakers that supposedly work well without treatments:

    http://www.decware.com/newsite/ERR.html

    Also, these being highly efficient is a plus for me, as I use an EL84-based amp, so about 22wpc.

    Right now, I seem to have a resonance or sympathetic frequency somewhere in the room that causes a rattle. I spent hours messing with the anti-skate on the turntable, thinking it was mis-tracking, till I discovered I got the same rattling when I played the CD of the problem song. I've been through this before in another room with my guitar amp -- I thought the speaker was loose, or something, until I tracked it down to a window or some such thing, after spending way too much time messing with my (perfectly functioning) amp.
     
  8. jupiterboy

    jupiterboy Forum Residue

    Location:
    Buffalo, NY
    My old speakers were semi-omni. I think you will like them.
     
  9. Hipper

    Hipper Forum Resident

    Location:
    Herts., England
    Can you hear this null at 65Hz? It's possible the null is so narrow that you won't notice it, meaning you needn't do anything about it.

    RealTraps offer a free download of test tones from 10 to 300Hz at 1Hz spacings. You can use this to hear if you are missing anything:

    http://realtraps.com/test-cd.htm

    Whilst I've not tried this, I heard the following suggestion: when playing the 65Hz tone, if you notice the null at your hearing position it may be that it will be louder at some other location in your room. If you can find that location you could employ absorbers there which should improve the 65Hz at your chair.
     
  10. Hipper

    Hipper Forum Resident

    Location:
    Herts., England
    Test tones to find that resonance should help here.
     
  11. Kyhl

    Kyhl On break

    Location:
    Savage
    A couple more points.
    Treat with broadband absorbers. Don't focus on the 215hz. 215 is probably a collection of harmonics from lower frequency problems. Dealing with the lower frequencies will usually tame those lower mids on their own. Yes, I consider 215 to be midrange because it's the bottom end of male vocals.

    Treat the null by finding the corresponding mode and treat that. The null is created when the reflection of a mode arrives at your listening position. Play the 65hz tone and walk around the room looking for the loud point. There will be one. Place the trap there. Trap the loud point so that it does not reflect back to the listening position where it creates the null.

    I'm curious if your waterfall chart shows ringing at 54hz or 43hz, both harmonics of 215hz. If there is ringing at those frequencies, then find the mode associated with them and place the trap there. Remeasure and see if things smooth out.
     
  12. jupiterboy

    jupiterboy Forum Residue

    Location:
    Buffalo, NY
    This shows the big scoop out pretty well. I can change it with positioning a little, but I can also see stuborn areas that remain.

    [​IMG]
     
  13. Kyhl

    Kyhl On break

    Location:
    Savage
    Are these the Vandersteen 1B's? I looked at the graphs on these speakers in Stereophile online and they should be fairly flat bass down to 50hz.
    This suggests so me to start with speaker placement to bring the bass up. Don't worry about boomy yet. Boomy may be able to be tweaked later with placement and trapping.

    Based on the missing 50hz-75hz I'd start with placement to fill that in. Or at a minimum, look for the 63-ish hz mode.
     
  14. jupiterboy

    jupiterboy Forum Residue

    Location:
    Buffalo, NY
    This is not the Vandersteens, but they measure similar, which indicates the room. If I bring them out a bit I can improve things, which looks like this by comparison.

    [​IMG]

    The purple indicates my best measured room placement, taking other factors into consideration as well. The right speaker is in a corner and the left sits out in a larger section of the room, so there is great asymmetry in the arrangement. Maybe I should start with the right front/back ceiling corners.
     
  15. Kyhl

    Kyhl On break

    Location:
    Savage
    More thoughts on this. Sorry to spam the thread.

    Overlay the phase angle on the frequency graph. Is there some funky phase flipping going on in that 60-70hz range? If so, try placement again to see if you can affect the phase angle. I would remove the pannels from the room to do this. Then bring the pannels back in and place once the speaker placement is set.
     
  16. Kyhl

    Kyhl On break

    Location:
    Savage
    Ah, that makes more sense to me. Now we see the ringing at 48hz and you picked up a lot of bass energy at 67hz. Can you tweak the placement a little more to deal with the 67hz?
    Then I'd put a trap on the 48-ish mode and remeasure. Then try placing on the 67hz mode and remeasure and see which one you like better.
     
  17. jupiterboy

    jupiterboy Forum Residue

    Location:
    Buffalo, NY
    Probably so. One of my realizations with placement and having a mic is that I can place the left speaker farther into the room/farther from the imaginary back wall to get the drivers the same distance from the listening position. The green chart is with speakers same distance from back wall and closer together. No traps in place at the moment. I am trying to decide what to order first.

    To avoid a worse thread hijack, we can discuss here:

    http://forums.stevehoffman.tv/threa...folded-transmission-line-loudspeakers.365267/

    and thanks for the ideas. I was getting nothing solid from the manufacturers consultations and other forums. Very much appreciated.
     
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