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thsi dosnt make sence

Discussion in 'Amps and Cabs [BG]' started by fenderbluesdude, Apr 10, 2004.


  1. i own a avatar b212 (2x12 cab 1000watts) and a behringer bx3000t head (300watts i dont care what you think, i like it ) the 2x12 cab is 8ohms i will soon be adding a 2x10 on top, basically i am only pushing 180watts through the cab. when we practicing in my drummers room i didnt seem to be loud enuff it was almost perfect but it just wasnt loud enuff for some reson. then the next day we moved into the living room which was just a little biger than his room. and when we strarted to play i was about 2 times louder and it was a bat out of hell then. and then the neck day we had a outdor gig. i didnt go through the pa but i was still loud and everbody could hear me just perfect. why is it that i seemed to be louder in bigger rooms or biger places. but not loud enough in small places? my volume was the same in the three places and the guitarest volumes was the same also.
     
  2. ihixulu

    ihixulu Supporting Member

    Mar 31, 2000
    getting warmer
    Room acoustics, or how the room reflects and absorbs the sound, has a huge imapct on how loud the bass sounds. Try moving your rig around in the small room to find the sweet spot if there is one. If there isn't one, you may want to put your rig up on some crates (make sure it's stable up there!) so that it is closer to your ears.
     
  3. 7flat5

    7flat5

    Nov 28, 2003
    Upstate NY
    Hey, dude,

    Oh, golly, I hope some of the more articulate and practically knowledgeable folks on this excellent forum chime in and clarify my pending response, but here goes.

    This absolutely makes sense, and it has everything to do with the acoustics of bass vs. the drums. Bass tones are the most room-determined frequencies. In a small room, low notes are limited most by the room dimensions. It takes a big room to allow a note to sound that has a half-wave length of 20 feet. In a room whose smallest dimension is less than the half-wave length of the note being produced, the note is just not there. And, for frequencies in the octave or two above the note whose half-wave length is the longest dimension of the room, there are severe peaks and valleys, resonances and cancellations, if you will. For the drums, the sound is all transients (snare, toms) and very high frequencies (cymbals) which just thrive in a small room. So, they sound much louder than they do in a large room or outside. You know this--a drum set in a bedroom is wicked loud, but in an auditorium, play hard and without reinforcement, it sounds like not much. But, the bass blooms in an auditorium.

    If I am talking Greek here, you need to do some homework. I wish I could point you to some websites with some information on room acoustics, but I just don't know of anything off-hand.

    One more thing, amp-related. Bass players are sort of ohm-conscious but ohm-ignorant at the same time. In general, an amp delivering 150 watts into 8 ohms and the same amp delivering 300 watts into 4 ohms are resulting in exactly the same decibels in sound energy. And, 300 watts into 8 ohms is only 3 dB louder than 150 watts into the same speaker.

    So, if this all causes consternation, I hope someone more technically saavy than me can follow up.

    Half-dim (that is, 7flat5)
     
  4. so basically when bass is in a small room the waves are so big that they just travel outside the room.
     
  5. 7flat5

    7flat5

    Nov 28, 2003
    Upstate NY
    Well, no. "The waves" are just the air vibrating. If the walls are cement, like in a basement, the speaker tries to move the air, but if the room is too small, the air just can't move at that frequency. If you were in a room with flexible walls, like a dry-wall on frame structure, then the walls might flex and the bass might even sound louder outside than inside the room. But that's not because the waves move outside, it's because the whole structure vibrates at the low frequency.