I've just recently finished my dipole speakers, I'm very impressed with the sound (as are my friends). I used Peerless HDS tweeters (810653) and a pair of Phillips PRS 602 6 1/2'' mids ,a cast frame 4 ohm ex-car audio speaker (don't laugh)
The mids were extremely co-operative in dipole and needed no x-over what so ever, and the Peerless tweeters got away with a single series 2.2uf poly cap.
I'm getting a +-3db response from 80hz to 20k, pretty stoked with that, so I decided to add some active bottom end, and that's where the problems started.
I have an 8'' sub in a TL (can just be seen behind the electronics and under the telly in the attached pic) that's powered by a plate amp with switchable 0-180 phase (as well as gain, freq ect) but no matter which position phase switch is in I get a huge chasm at 50hz (response pics will follow)
I initally thought it was some weird interaction between the TL and the dipole speakers so I quickly rigged up a 12'' in one of my sealed test enclosures but ended up with the same result.
Now granted with just the sub alone the "room" is a bit weak at 50hz but no where near the dip that happens with the dipoles running.
Thoughts?
The mids were extremely co-operative in dipole and needed no x-over what so ever, and the Peerless tweeters got away with a single series 2.2uf poly cap.
I'm getting a +-3db response from 80hz to 20k, pretty stoked with that, so I decided to add some active bottom end, and that's where the problems started.
I have an 8'' sub in a TL (can just be seen behind the electronics and under the telly in the attached pic) that's powered by a plate amp with switchable 0-180 phase (as well as gain, freq ect) but no matter which position phase switch is in I get a huge chasm at 50hz (response pics will follow)
I initally thought it was some weird interaction between the TL and the dipole speakers so I quickly rigged up a 12'' in one of my sealed test enclosures but ended up with the same result.
Now granted with just the sub alone the "room" is a bit weak at 50hz but no where near the dip that happens with the dipoles running.
Thoughts?
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Erik said:
I have measured the sub (both sub setups) and while there is a dip at 50hz the dipole speakers seem to make it worse, regardless of phase.
So to try and get around the room problem I try some different sub postions? or listening positions? the layout of the listening area is pretty flexable (I live by my self so I can do whatever I want
)Depends on the room dimensions.There are 3 normal different possible phase (high peaks or low peaks) in an in-room response.If you divide all 3 room dimensions(x,y.z) by 1/2 wavelength (of the problem frequencies) i would bet that some or all of the peaks/nulls fall within those numbers.
In my room i have bass traps in the corners, mid traps high on the wall between the horns, and high traps behind the listening position.This helps some with in room response but will not eliminate it totally.
ron
In my room i have bass traps in the corners, mid traps high on the wall between the horns, and high traps behind the listening position.This helps some with in room response but will not eliminate it totally.
ron
Two things come to mind:Volenti said:I have measured the sub (both sub setups) and while there is a dip at 50hz the dipole speakers seem to make it worse, regardless of phase.
So to try and get around the room problem I try some different sub postions? or listening positions? the layout of the listening area is pretty flexable (I live by my self so I can do whatever I want
1. What's the response of the sub alone? Measure this in its current (corner) position and also out somewhere in the middle of the room.
Perhaps the transmission line needs tuning by adding or subtracting stuffing.
2. Then experiment with room positioning of both the sub and the dipoles. Perhaps the dipoles need to be further away from the corners. Also experiment with the listening position.
Personally, I would start by playing with the dipole positions (and listening position) without the sub. Get this optimized before playing with the sub position.
Generally dipoles are difficult to integrate with a conventional (or TL) sub. Have you considered a dipole sub? Check the Linkwitz site.
Good luck
You've got your problem solved, it seems, but if I could suggest: you've got your dipoles in corners. This is not the optimal way to run them; dipoles need room to breathe. I suspect that if you move them away from the wall and leave the sub under the TV or something, you'll get a better response.
Good luck, in any case.
Good luck, in any case.
Nappylady said:
Yea thanks, I've moved them further out from the corners, about 4' now, that's almost got rid of the slight male voice resonance that was the only other issue I had, I'll continue to experiment and probably re-arrange the listening area to give me the area to space them properly.
One thing I've notice with combined dipole and monopole bass is that the responses do not match.
In other words, the spot where dipole bass sounds great will often sound awful for monopole.
Ideally you would have dipole subs, but if you don't, forget the usual audio laws like putting a monopole sub on the same plane as your dipoles. Something weird will happen.
Cheers
Steve
In other words, the spot where dipole bass sounds great will often sound awful for monopole.
Ideally you would have dipole subs, but if you don't, forget the usual audio laws like putting a monopole sub on the same plane as your dipoles. Something weird will happen.
Cheers
Steve
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