Subs Locations, and Woodfloors vs. Cement Floors

Discussion in 'Speakers & Subwoofers' started by Brian L, Aug 23, 2004.

  1. Brian L

    Brian L Cinematographer

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    Subject says it all.

    My sub (Hsu 1225) was previously in the right front corner of the room. Measured at the listening position (discrete test tones, SPL meter, the "poor man's spectrum analyzer") I was reasonably flat (+/- 3db perhaps from 25 hz to 80hz). Note that I do use EQ on the sub; AudioCOntrol Bijou with 1/6th octave centers from 22.5 to 80 Hz. Tracks with extreme bass (Star Wars Attack of the Clones, U571, Nemo) never failed to satisfy.

    But it was most often bass I could hear, more than I could feel. I was not getting that "my room literally shook" stuff so many users report. But maybe I know why.

    My room has cement floors. As I learned while setting up a friends rig in a room with wooden floors, even though my sub had much better low end extension than his, the tactile sensation in his room was much better. I presume this to be because I was getting the vibrations through the wooden floor and couch, vs. my cement slab.

    Fast forward. We just completed a minor den remodel, which included some new speaker cable run under the rug. I took the opportunity to run an extra line for the sub so I could try it behind the couch (which is to the back of the room). Dr. Hsu (Hsu Research) offers this as an alternative location in the paper work that came with the 1225, but I never was able to try it.

    Summary of the experiment: Yeee Haaa!

    With the sub behind the couch (literally laying sideways leaning lightly against it), I think I now know what the folks with Bass Shakers feel. The rumble in the couch is astounding.

    And on top of that, measured and EQ'd, my room response in the low bass is flatter than I ever had in the front corner. With the exception of a 2dB bump at 31.5hz and a 4 dB bump at 35.5hz, I am dead flat on the 1/6th octave centers that my EQ has from 25 up to 80 hz.

    If I could find a couple bands of Parametric EQ cheap (I know...Behringer FBD), I could probably be pancake flat.

    Now, can I localize the sub being that close? So far, for films, no. But for MC music, maybe, depending on the level of the sub (I am still tweaking levels for the best blend).

    As for 2CH music...haven't tried it yet. I suspect having the sub 14 feet from the mains will be a problem unless I drop the crossover lower than 80hz, but for action films...what a blast.

    All that being said, I suspect that none of this would be required if I had wooden floors, but boy, I am sure glad I gave it a shot. Much cheaper than laying a wood floor on top of the slab.

    When I make a change in the system, 9 out of 10 times, I am the only one that notices. Not so with this...wife and daughter had big 'ole grins when we played the opening scenes of SW AOTC.

    BGL
     
  2. terence

    terence Supporting Actor

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    My subs are on wood floors because they are upstairs, and i love the taticle feel i get below 20Hz. I have also felt the same on cement but with less authority. Some people like wood floors, some don't. I perfer wood.
     
  3. Brian L

    Brian L Cinematographer

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    I think I have read in some of Russ Herschelmann's writings that he likes wooden floors, and also walls with some flex built in (a single layer of sheetrock rather than a double) since it helps with standing waves and such. He suggests that concrete walls and floors are harder to work with.

    While I am in now way an acoustician, that suggestion does seem to be intuitively reasonable. Of course, I will not be rebuilding HT HT room any time soon, so it will all remain strictly theoretical for me.

    At lunch today, I did play some 2CH music with decent bass, and found that, if I keep the sub at a reasonable level, it does blend well with the fronts. If I crank it to silly levels, it does call attention to itself.

    The experimentation will continue......

    BGL
     

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