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  1. #1
    Suspended atomicAdam's Avatar
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    Where did my lows go?

    So, I though I would be smart, move room with the wife. She had a smaller darker room, I had the larger lighter room. My thinking was that with a smaller room I won't have to turn my music up too so much to enjoy it. I live in a small apt and I don't want to be 'that guy'.

    Well, the new room is much smaller. 8ft wide by 11ft long. It can be fully sealed off, well, not air tight, (sorry RnT, cant suffocate), but closed off. The larger room can not.

    The speakers are pointed length wise, the floor has carpet, and back wall has a bookshelf. One side has windows with cloth covers, the opposite side has a wall with matched cloth as the window shade. There is some sound proofing foam on the corners behind and to the right of the right speaker and left of the left speaker, but none in the middle. (I found with the foam the sound is much tighter, cleaner).

    The sub, when on, not often now, is between the speakers, which are about 4.5ft apart. I sit either close, like 4ft away, or far, 6ft away.

    What I've noticed is now with the sub on, there is hardly an extra thump. The speakers go down to 50hz, which in the old room wasn't low enough to hear, but in the new room are fine. But the sub in the new room hardly makes a squeak. It's on, working correctly.

    I guess, the question, is it possible to have a room be too small?

    I know that comparing the larger room to the smaller room the speakers don't sound as bright and lively. For a couple reason I would image. 1) Less reflection off walls in the larger room, and 2) i sat so far away from the speakers in the larger room it is possible the low frequency sounds just weren't making their way proportionally across the room at lower levels.

    Any thoughts on room size? The speakers are just standard Polk RTiA3 bookshelf speakers 5-1/4" Diameter mid range with a 100 watt Onkyo amp and VA Omega III preamp. The sub in an old KEF - prob 6" passive sub run from another Onkyo 100 Watt amp.

    Maybe there isn't enough air in the room to move and sound correctly. This concerns me, because the wife wont let me change rooms back, and I've got my eyes set on some larger floor standing speakers in the future.

  2. #2
    Phila combat zone JoeE SP9's Avatar
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    Maybe a room that small can't support low frequencies. Just a thought.
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  3. #3
    _ Luvin Da Blues's Avatar
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    Have you tried other locations for the sub? Sounds like you have acoustical cancellation going on at the low freqs.
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  4. #4
    Suspended atomicAdam's Avatar
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    Quote Originally Posted by Luvin Da Blues
    Have you tried other locations for the sub? Sounds like you have acoustical cancellation going on at the low freqs.
    Yes, I've moved the thing around the room. back corners, back middle, front corners, front lower middle. (way below speakers) only place i've not tried it is on top of the bookshelf in the back. nothing seems to help.

  5. #5
    Retro Modernist 02audionoob's Avatar
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    Does your sub have a phase switch?

  6. #6
    Forum Regular Florian's Avatar
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    Liste to Joe :-)
    Lots of music but not enough time for it all

  7. #7
    My custom user title This Guy's Avatar
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    Quote Originally Posted by 02audionoob
    Does your sub have a phase switch?
    Yeah try switching the black and red wires on that passive sub, although I don't know how much bass a 6" subwoofer would provide in the first place.

  8. #8
    Suspended atomicAdam's Avatar
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    Quote Originally Posted by 02audionoob
    Does your sub have a phase switch?

    no phaze switch, it is totally passive

  9. #9
    Suspended atomicAdam's Avatar
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    Quote Originally Posted by This Guy
    Yeah try switching the black and red wires on that passive sub, although I don't know how much bass a 6" subwoofer would provide in the first place.

    lol - i've tried that even. thought the wires are set up correctly. guess there just isn't much hope. thanks

  10. #10
    Shostakovich fan Feanor's Avatar
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    Room size

    Quote Originally Posted by atomicAdam
    ...

    Well, the new room is much smaller. 8ft wide by 11ft long. It can be fully sealed off, well, not air tight, (sorry RnT, cant suffocate), but closed off. The larger room can not.
    ...

    Maybe there isn't enough air in the room to move and sound correctly. This concerns me, because the wife wont let me change rooms back, and I've got my eyes set on some larger floor standing speakers in the future.
    A room of 11' is inherently incapable of reproducing sound below about 50 Hz, since 11' is the half-wave length of a 50 Hz sound wave. You can try to reproduce deeper but all you'll get is distortion.

  11. #11
    Suspended atomicAdam's Avatar
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    Quote Originally Posted by Feanor
    A room of 11' is inherently incapable of reproducing sound below about 50 Hz, since 11' is the half-wave length of a 50 Hz sound wave. You can try to reproduce deeper but all you'll get is distortion.

    Bingo, that is what I was looking for. Thanks. Now, where did you learn this, or what did you need to know to come to this conclusion.

  12. #12
    Shostakovich fan Feanor's Avatar
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    Not me

    Quote Originally Posted by atomicAdam
    Bingo, that is what I was looking for. Thanks. Now, where did you learn this, or what did you need to know to come to this conclusion.
    I'm no acoustic engineer, but my understanding is that you can't reproduce a frequency in a space that can't accomodate at least half the wave length of that frequency, that is, a complete positive or negative phase.

    The speed of sound varies but is around 1130 ft/sec. The room size is 11 ft. 1130/11 = 102.7 Hz. However that represents the full wave, both positive and negative phases, and you only one phase to reproduce the sound, hence 102.7 / 2 = 51.4 Hz.

    I'm not sure the effect of having the other dimensions shorter than 11 ft. You might need two or even all three dimensions >11 ft to produce the 51.4 Hz without distortion, though that's not my present understanding.

  13. #13
    Suspended atomicAdam's Avatar
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    Quote Originally Posted by Feanor
    I'm no acoustic engineer, but my understanding is that you can't reproduce a frequency in a space that can't accomodate at least half the wave length of that frequency, that is, a complete positive or negative phase.

    The speed of sound varies but is around 1130 ft/sec. The room size is 11 ft. 1130/11 = 102.7 Hz. However that represents the full wave, both positive and negative phases, and you only one phase to reproduce the sound, hence 102.7 / 2 = 51.4 Hz.

    I'm not sure the effect of having the other dimensions shorter than 11 ft. You might need two or even all three dimensions >11 ft to produce the 51.4 Hz without distortion, though that's not my present understanding.
    That seems like a fair assessment of the problem. The Polk speakers have way more lows than they did before, and the bottom out at 50hz.

    This means that for the new floorstanding speakers I have in my mind which bottom at 32hz, I am going to be missing some sound. Interesting. Oh well. Thanks Feanor

  14. #14
    Retro Modernist 02audionoob's Avatar
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    Cool Eureka

    There was a time when I wondered aloud here what defined a small room. The impetus at the time was the reference Dynaudio made to such things in their literature for the Audience line. They published a table of recommended minimum amplifier ratings based on small, medium and large rooms. The Audience 82 can reportedly get down to something like 26Hz, so maybe that's why they made recommendations for it in medium and large rooms, but not small...not being able to accommodate the wave length.

  15. #15
    Forum Regular Kevio's Avatar
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    Nice try but wrong. There is no such limitation (headphones work just fine in much more constrained dimensions).

  16. #16
    Suspended atomicAdam's Avatar
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    Quote Originally Posted by Kevio
    Nice try but wrong. There is no such limitation (headphones work just fine in much more constrained dimensions).
    You know when I went on my run today I thought about the same thing. Just came back here to make a comment and whamp, you beat me to it. Headphone do work on a different power scale so maybe that explains why they work.

    If you dont think it is wave length got any suggestions?

  17. #17
    Shostakovich fan Feanor's Avatar
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    But ...

    Quote Originally Posted by Kevio
    Nice try but wrong. There is no such limitation (headphones work just fine in much more constrained dimensions).
    Headphones work directly on your ear channel. They don't need the medium of the room to convey the sound.

  18. #18
    Forum Regular blackraven's Avatar
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    With all things being equal but the room size, wave length is the logical explanation other than the sub is not working correctly. You could try placing the sub back in the larger room to test this.

    One last thing, do you have more sound deadening material in the smaller room such as carpet, window treatments etc.?
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  19. #19
    Suspended atomicAdam's Avatar
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    Quote Originally Posted by blackraven
    With all things being equal but the room size, wave length is the logical explanation other than the sub is not working correctly. You could try placing the sub back in the larger room to test this.

    One last thing, do you have more sound deadening material in the smaller room such as carpet, window treatments etc.?

    I do an I don't. I think I've got the same amount, just in a smaller amount. So, proportionally, yes, there is a larger amount of sound deadening material, but I don't believe it is over done. Spent a couple days testing out foam in different places.

    On the room size issue. It is interesting, a 20ft long room would only allow, per say, lows to 28hz.

    I'm going to unplug and replug everything back in. One difference is now the Onkyo amp to the sub is getting it's source directly from the pre-amp (it has two lines out). Before it was daisy chained from one amp to another. I'lll try switching back.

    Too bad there doesn't seem to be a hard tested scientific case of room size to frequency.

  20. #20
    Forum Regular Kevio's Avatar
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    Quote Originally Posted by atomicAdam
    If you dont think it is wave length got any suggestions?
    No, I wouldn't hesitate to post if I did. Personally I'd try to EQ it. If that doesn't fix it, it might at least lead you closer to the actual problem.

    And yeah, wiring the system the same way you did in the other room would be a good idea

  21. #21
    Phila combat zone JoeE SP9's Avatar
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    If the door to the room is on one of the short walls open it completely. If you get better bass you have your answer. If this is the case no amount of Eq of any type will make a bit of difference.
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  22. #22
    Forum Regular Florian's Avatar
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    My system has a response (-3db) at 11.5Hz.

    In my old room (22ft long) i was missing the very bottom on some pipe organs on Vinyl. In my new room which is 40ft long i get that and more. I believe its the room size also.
    Lots of music but not enough time for it all

  23. #23
    Forum Regular audio amateur's Avatar
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    My room is no more than 12 feet long and I get about 40Hz @ -3dB from my small standmount speakers.

  24. #24
    Suspended atomicAdam's Avatar
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    Quote Originally Posted by JoeE SP9
    If the door to the room is on one of the short walls open it completely. If you get better bass you have your answer. If this is the case no amount of Eq of any type will make a bit of difference.

    no better base - at least not yet - i am going to recheck the wires today - though it is nice and sunny outside - i might have to postpone the wire check and go for a walk

  25. #25
    Shostakovich fan Feanor's Avatar
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    Pretty smug, eh?

    Quote Originally Posted by audio amateur
    My room is no more than 12 feet long and I get about 40Hz @ -3dB from my small standmount speakers.
    You may feed your system 40 Hz and you might get -3 dB. But here's the catch: you might not be hearing a pure 40 Hz sound. Instead you are getting distortion.

    In a rooms too small to reproduce a certain frequency, all that power you're feeding has to go somewhere. It creates distorted sound at a higher frequency than the input signal.

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