Deang Posted December 10, 2002 Share Posted December 10, 2002 I know this has come up before, but can't find the thread. Bob Gassel even jumped in with some numbers. Does anyone remember the formula for this? It has to do with the total area of the ports in relation to the wall behind them. Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted December 10, 2002 Share Posted December 10, 2002 Have you attempted the Rule of Thirds yet which I believe supercedes distance of the port from the wall. Bring the speakers out a third from the rear wall (third of the distance of the length of your room)and sit your chair roughly 2/3 the distance of the whole room. And again, try to have the distance from the rear wall to be different from the side wall distance. I had my ProAc tower speakers over EIGHT FEET from the wall at one point. The port location seems to have more impact if the speakers are TOO close. The distance from the rear wall has more to do with your room size and speaker dimension than relating to the port etc. kh ps- btw, you didnt need to remove that link to your equipment site; I havent even taken it off yet. Quote Link to comment Share on other sites More sharing options...
Deang Posted December 10, 2002 Author Share Posted December 10, 2002 I know, but you were going to remove the link sooner or later, so I just figured by changing my signature -- you wouldn't feel bound to leave it. I don't think I can really do the rule of thirds (I am familiar with it). Though the wall behind me is some ways back, there is a king sized bed a foot or two behind my listening chair. Quote Link to comment Share on other sites More sharing options...
justin_tx_16 Posted December 10, 2002 Share Posted December 10, 2002 What IS the link to the page? I don't think I have seen it! Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted December 10, 2002 Share Posted December 10, 2002 You can leave the link up for awhile as I am not doing going to remove those files off that space yet as the billing doesnt change for awhile so no sweat, although if you want changes to it, you can do the text. Does the king size bed come out more than 1/3 the length of the room from the wall behind your head? kh Quote Link to comment Share on other sites More sharing options...
aab3rd Posted December 10, 2002 Share Posted December 10, 2002 Along the same lines, does distance from wall apply to passive radiators on models such as the Forte or Chorus? Quote Link to comment Share on other sites More sharing options...
jnorv Posted December 10, 2002 Share Posted December 10, 2002 If you read up on the theory of Helmholtz resonators, there is an end correction for the port length terminated in an infinite baffle that is equal to .85 times the radius of the port. As a first order approximation, I would use this distance. You could, also, adjust the distance to the wall until the box frequency starts to change, determined by measuring the speaker impedance as a function of frequency. Or you could just keep moving it closer until you hear a change in the bass. Jim N Quote Link to comment Share on other sites More sharing options...
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