It's the pressurisation as a comfort issue I don't like, I have U frame subs at the moment and I prefer them in this respect to sealed, BR and TL in my room.
I don't know, I presumed after reading the SL article and my experience with room modes that minimal excitation would be best
Here is the link to the image of a corner dipole from SL's web site:
http://www.linkwitzlab.com/images/graphics/corner-dp.gif
It's reached via PHOENIX loudspeaker FAQ page, question #30, here:
Frequently Asked Questions
The only quirk that I see is that the main "+" lobe will be narrow and will have two nulls just 20 degrees to either side of it. If this points at your listening location, you are in luck!
http://www.linkwitzlab.com/images/graphics/corner-dp.gif
It's reached via PHOENIX loudspeaker FAQ page, question #30, here:
Frequently Asked Questions
The only quirk that I see is that the main "+" lobe will be narrow and will have two nulls just 20 degrees to either side of it. If this points at your listening location, you are in luck!
Reanimating the death I just tried it and it works very well.
https://www.diyaudio.com/forums/multi-way/123512-ultimate-baffle-gallery-266.html#2657
I can confirm the findings here
Designing Loudspeakers - Part 20 Open Baffle Room Responses
The integration of the woofer into the room and to the midrange is indeed much more smoother and easier. Less boomy and with only very simple filtering. One loses quite a bit at the low end but worth a try because of a much better/flatter response between 50 and 200 Hz. I use a low budget woofer so I need to cut below 40 Hz to get the thing loud enough. Another advantage may be that placement into the corners of the room will help where no placement > 1 meter from the front wall is possible.
https://www.diyaudio.com/forums/multi-way/123512-ultimate-baffle-gallery-266.html#2657
I can confirm the findings here
Designing Loudspeakers - Part 20 Open Baffle Room Responses
The integration of the woofer into the room and to the midrange is indeed much more smoother and easier. Less boomy and with only very simple filtering. One loses quite a bit at the low end but worth a try because of a much better/flatter response between 50 and 200 Hz. I use a low budget woofer so I need to cut below 40 Hz to get the thing loud enough. Another advantage may be that placement into the corners of the room will help where no placement > 1 meter from the front wall is possible.
^ Just seen this, interesting. Has anyone built this or similar? Corner Dipole Subwoofer | Parts Express Project Gallery
^OMG! A wreck by design. Side ports give most of output spl and the vent deep in the corner tries desperately to null it!
The open baffle plate woofer in the corner showed earlier has some chances of working. Same idea was used in Gradient Helsinki 1.5
Gradient Helsinki 1.5 loudspeaker John Atkinson, November 2010 | Stereophile.com
Here Gradient 1.3 and 1.5 side by side
Here with the designer Jorma Salmi (RIP)
The open baffle plate woofer in the corner showed earlier has some chances of working. Same idea was used in Gradient Helsinki 1.5
Gradient Helsinki 1.5 loudspeaker John Atkinson, November 2010 | Stereophile.com
Here Gradient 1.3 and 1.5 side by side
Here with the designer Jorma Salmi (RIP)
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^OMG! A wreck by design. Side ports give most of output spl and the vent deep in the corner tries desperately to null it!
The open baffle plate woofer in the corner showed earlier has some chances of working.
I would say that this type of subwoofer has "a lot of chances" to work.
The "battle" between the front and back radiation is not very different from other types of dipole subwoofers.
It actually worked very well.
I had design and build such a dipole subwoofer almost 20 years ago.
It was one of the best subwoofers I had for listening to music.
regards
George
Very simple to try
That's good news. It seems like the null would be in the horizontal plane? Saying that, With the wavelengths involved and the reflections I take your point about it not being very different than other types. The push-push arrangement has it's benefits and I think the original linked to is unnecessarily "well made".
Please see the project page here:
Corner Dipole Subwoofer | Parts Express Project Gallery
Comments from our dear readers:
The info on the design page is incomplete. You could operate this sub two ways:
1. The cones are always moving in the same direction at the same time. This would form a corner dipole, because air is being drawn in one side while being pushed out the other. The middle opening would not contribute to the output because the air in the middle cavity of the sub is just sloshing back and forth. I assume this is how the sub is intended to operate. The odd thing is that you would normally build this with one driver, not two. It's a bit of a mystery, and makes me think that the sub is being operated in the way described below, under (2).
2. The cones are simultaneously either moving towards each other or away from each other. This alternately pressurizes and rarefies the air in the middle chamber, and the air would then be forced out the hole/opening thru the top plate that is located in the room corner in the installation. This is not a dipole, but more like a corner loaded quadrupole or something. I assume the response when operated in this way you probably not be very good. Also the sizes of the side openings and the corner opening are quite different, which is not usually intended.
If operated under (1) above, it's a viable corner dipole, albeit with all of the baggage that comes with that design.
Corner Dipole Subwoofer | Parts Express Project Gallery
Comments from our dear readers:
The info on the design page is incomplete. You could operate this sub two ways:
1. The cones are always moving in the same direction at the same time. This would form a corner dipole, because air is being drawn in one side while being pushed out the other. The middle opening would not contribute to the output because the air in the middle cavity of the sub is just sloshing back and forth. I assume this is how the sub is intended to operate. The odd thing is that you would normally build this with one driver, not two. It's a bit of a mystery, and makes me think that the sub is being operated in the way described below, under (2).
2. The cones are simultaneously either moving towards each other or away from each other. This alternately pressurizes and rarefies the air in the middle chamber, and the air would then be forced out the hole/opening thru the top plate that is located in the room corner in the installation. This is not a dipole, but more like a corner loaded quadrupole or something. I assume the response when operated in this way you probably not be very good. Also the sizes of the side openings and the corner opening are quite different, which is not usually intended.
If operated under (1) above, it's a viable corner dipole, albeit with all of the baggage that comes with that design.
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From what I remember, there was no directivity at all.
The operation was as described in (2), probably not a true dipole subwoofer.
My measurement tools back at that time (it was around 1999-2000) were very limited, but I remember that after equalization the response was very flat and the sound was very good.
regards
George
The operation was as described in (2), probably not a true dipole subwoofer.
My measurement tools back at that time (it was around 1999-2000) were very limited, but I remember that after equalization the response was very flat and the sound was very good.
regards
George
I have used a lot of subwoofers in my living room during all these years.
Both dipoles and closed boxes.
To my opinion, the dipoles were always better.
It's difficult to describe it, but I would say that the sound was more "clear".
I agree it has to do with the fewer room resonances, but I will add also the lack of "boxinness".
If you compare side by side a closed box subwoofer and a dipole in the room, the first thing that you will notice, is this lack of boxiness of the dipole subwoofer.
regards
George
Both dipoles and closed boxes.
To my opinion, the dipoles were always better.
It's difficult to describe it, but I would say that the sound was more "clear".
I agree it has to do with the fewer room resonances, but I will add also the lack of "boxinness".
If you compare side by side a closed box subwoofer and a dipole in the room, the first thing that you will notice, is this lack of boxiness of the dipole subwoofer.
regards
George
I agree, i don't think you can call that directivity in an environment where the sound is created by a set of resonances. Outdoors it would be different of course.
As a former and satisfied dipole user, I think dipole is different and not necessarily better.
George, what do you think is the reason for not sounding boxy? Lack of pressurization below first room mode? Smoother room response because of less excitation of room modes? Less resonace noise from cabinet walls?
I have studied and used dipoles too, but not at all below 100Hz, I use closed box subwoofers. One reason is that I am not sure that they are a wise construction at all, other is that i can't find a reasonable location for such large things. A friend had 2x12" H-frame dipole (sub)woofers that I have listened to, and liked them in his dedicated listening "room" (cellar with heavy damping). It was funny to watch diaphragms flapping!
I have studied and used dipoles too, but not at all below 100Hz, I use closed box subwoofers. One reason is that I am not sure that they are a wise construction at all, other is that i can't find a reasonable location for such large things. A friend had 2x12" H-frame dipole (sub)woofers that I have listened to, and liked them in his dedicated listening "room" (cellar with heavy damping). It was funny to watch diaphragms flapping!
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This makes me want to get a pair of these: https://hadex.cz/spec/q378.pdf put them each on a simple baffle and stick into the corners
My experiment with an H-type open-baffle solution showed no decrease in room resonances, and an additional one caused by the H-structure. I think there's a reason why you hardly ever see in-room response curves for dipole bass solutions
.FWIW, if you're hearing box resonances in a sealed subwoofer, that IMO means that the box is not properly damped.
The Subwoofer DIY Page v1.1 - Projects : An INF10 Dipole Subwoofer
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