I've found having it reflected unimpeded to be best in my room, they are aligned straight on with the front wall which is plaster on stone
I've been able to compare the two quite simply, the Jordans are in the VTL cabinet but the back is removable, I prefer them as dipoles
I totally agree with that.Without back wall the listening gets more relaxed from subjective point of view.
I use a 130Hz crossover, it would depend on your baffle and the room placement what you can get away with, you have plenty of flexibility to play around with your mini DSP
O.K. Scott, I need your help in stopping this wall nomenclature insanity! The title of your thread says 'front wall' yet others have referred to it as the back wall. From the speaker's point of view it's the back wall since it's behind them. However from the listener's point of view it's the front wall since it's in front of them. It's my room and my wall so I contend it should be called the front wall! I sound like my dad.
Oh, it's the other wall? Anyway I feel inclined to point out at this point that a dipole can be a narrow band phenomena and that an open baffle isn't automatically a dipole. That said, I still feel that whatever reflections you create, and how, are the end result of interest.
I think it's fair to say that an open baffle isn't automatically a dipole and doesn't give that figure of 8 radiation pattern as Charlie has measured and others have observed. And the bass doesn't cancel as much as the calculations would have you believe. Then place it in a room at the requisite minimum distance, perhaps maximum distance no more than about 6 feet(?) from the wall in front of you 😉 and enjoy those reflections......
Where can I learn more about this ~120hz suck-out with dipole speakers? Can you please post links to any papers, forum discussions? Thanks.
This might help Boundary effects
The "thing" with dipole bass is that it's rear wave is in opposite polarity. Near the wall it will be opposite polarity even reflected, so summed will attenuate. Monopole will accentuate in low end. Until the phase turns over.
Calculators like SBIR work only with monopoles.
An externally hosted image should be here but it was not working when we last tested it.
The "thing" with dipole bass is that it's rear wave is in opposite polarity. Near the wall it will be opposite polarity even reflected, so summed will attenuate. Monopole will accentuate in low end. Until the phase turns over.
Calculators like SBIR work only with monopoles.
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sorry zmyrna I dont know of any links or papers. Years ago I was well into development of a planer bass panel and was hearing HUGE differences in bass dynamics with different positioning. Some say that dipole is easy to position for bass region due to less room interaction. Well there is some truth to that BUT the issue I was hearing I think had to do with the subjective effects of a dip in FR around 80-120 hz. This is an area I believe has a lot to do with how puncy and dynamic percussion sound can be.
Anyway I found out that at different distance from wall will change this suckout. it has to do with the wave bouncing off back wall and cancelling the positive wave coming from speaker.
Even a monopole has some of this issue I believe but it is perhaps hidden better in the sea of room effect issues??
I liked open baffles 6' from front wall.
That way the wall bounce would be >10mS, sounded better to me than when closer.
If that is not an option, you can wrap the back side with foam or towels.
But it is up to your ears what you like best !!!!!!!!!!!!!!
That way the wall bounce would be >10mS, sounded better to me than when closer.
If that is not an option, you can wrap the back side with foam or towels.
But it is up to your ears what you like best !!!!!!!!!!!!!!
I decided to not have dipole low bass, when I was tinkering about AINOs. My idol Gradient 1.3 has monopole downfire bass, and also the just released Gradient 1.4
Monopole bass is actually omnispheric in dispersion and it is not so critical to positiong, at frequencies below 100Hz and is also more efficent even as a closed box. When we cross a omni/mono to a dipole or cardioid, the transition range is cardioid. Front wall first reflection is in most real in-room cases somewhere between 100-400Hz, just like the floor reflection null. If these happen at same frequence, we get really severe suck-out. At worst scenario also sidewall first null happens there too!
Important thing to remember is that it is impossible to eq first reflection nulls by setting a peak correction to signal! If we try that, also the amplitude of reflection goes up and the sum is still zero! This applies also to front-wall cancellation of dipole low bass, it is impossible to eq!
An externally hosted image should be here but it was not working when we last tested it.
Monopole bass is actually omnispheric in dispersion and it is not so critical to positiong, at frequencies below 100Hz and is also more efficent even as a closed box. When we cross a omni/mono to a dipole or cardioid, the transition range is cardioid. Front wall first reflection is in most real in-room cases somewhere between 100-400Hz, just like the floor reflection null. If these happen at same frequence, we get really severe suck-out. At worst scenario also sidewall first null happens there too!
Important thing to remember is that it is impossible to eq first reflection nulls by setting a peak correction to signal! If we try that, also the amplitude of reflection goes up and the sum is still zero! This applies also to front-wall cancellation of dipole low bass, it is impossible to eq!
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It's interesting to concentrate on the reflections of open baffle bass. The requirements appear to be slightly different than further up the spectrum. They need to be a certain distance from the front wall in order to have any reasonable bass, but too far away and the cancellation caused by reflection can be below the crossover point. Floor reflection shouldn't be a problem for bass and also if they are placed close to or against the side walls this reflection too is no problem
Maximum distance from front wall for OB is 40 feet. 30-35 is about as far as you normally want to go.
Easy question.
Easy question.
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