Quasar positioning (BD-Design)
by Ken 
, Monday, June 26, 2006, 20:26 (6520 days ago)
Hello Bert,
I just looked at your website. Very nice!
I like the concept of the Quasar. However, as the speakers are very large, and are a dipol, how critical is it to position them? As what I understood, dipols shouldn't be too close to a wall (side and back). And what should be the minimum distance between two speakers?
As my room is not too big, an alternative could be to build a singular or the Fostex enclosure. I also red that Tony Gee created a FE-206E enclosure, with a tweak to solder the mass of the speaker to the minus connection of the speaker and covering the magnet with damping. Did you try that with your Quasars/Singulars?
I am sorry for asking so many questions, but the FE-206E somehow seems very interesting to build a speaker with.
Best regards,
Ken
Quasar positioning
by Niels van der Linden , Tuesday, June 27, 2006, 05:14 (6520 days ago) @ Ken
Optimal positioning is having the best direct vs indirect sound ratio. So this would be having them facing in and listening a little inside the triangle it creates.
Don't worry too much about distance to the side wall; anything from half a meter is fine (wall to center of speaker), although it should be precisely the same on both sides.
This is my situation:
http://my.hifi.nl/index.php?user=1088
Quasar positioning
by Bert , Tuesday, June 27, 2006, 12:01 (6520 days ago) @ Ken
Hi Ken,
I just looked at your website. Very nice!
Thanks!
I like the concept of the Quasar. However, as the speakers are very large, and are a dipol, how critical is it to position them? As what I understood, dipols shouldn't be too close to a wall (side and back). And what should be the minimum distance between two speakers?
The Quasars like to have space around them for the most free presentation. Having them closer to the side walls (>50cm) is not a major problem though.
The minimum distance between the speakers is not important, having them closer will only reduce the width of the "image".
As my room is not too big, an alternative could be to build a singular or the Fostex enclosure. I also red that Tony Gee created a FE-206E enclosure, with a tweak to solder the mass of the speaker to the minus connection of the speaker and covering the magnet with damping. Did you try that with your Quasars/Singulars?
The Singular likes to have some space too but not as much as the Quasars. The Singulars are relative deep so the driver itself will be just as far into the room.
I never tried to dampen the magnets but I did try to ground the mass of the speaker and that does improve clarity (although not huge). I connected the mass to earth (the mains), not to the minus of the speaker terminal. This only works if the minus is connected to the ground of the amp/earth which is not always the case.
Ciao,
Bert
--
BD-Design - Only the Best!
Quasar positioning
by Ken , Saturday, July 01, 2006, 13:31 (6516 days ago) @ Bert
Thanks for your answers. I am looking for new main speakers for my listening room in the attic. The problem is of course the slanted roof, which limit the standing space.
Do you have any frequency response measurements available? I am quite interested how they respond.
Best regards, Ken
Quasar positioning
by Bert , Sunday, July 02, 2006, 17:53 (6514 days ago) @ Ken
Hi Ken,
Do you have any frequency response measurements available? I am quite interested how they respond.
Sorry, I do not have usefull frequency plots for the Quasar. It won't be of any use anyhow simply because your room will act differently than mine (i.e. boundairies, standing waves, placement of them, etc.
Ciao,
Bert
--
BD-Design - Only the Best!
Quasar positioning
by Ken , Monday, July 03, 2006, 13:00 (6514 days ago) @ Bert
Hi Bert,
To my knowledge, standing waves etc. occur most of the time on the lower frequencies. The FE-206 rises in volume after approx. 1.2 Khz. Or is this compensated per EQ? Or do the BD-15 support below 1.2 kHz?
I've heard that the baffle width also has a possitive effect on the lower freq. response of a full range speaker (positive use of the baffle step(?)the German magazine Hobbyhifi used this tric in their Dacapo project.
Thanks for anwering my many questions 
Best regards, Kenneth
Quasar positioning
by Bert , Monday, July 03, 2006, 23:03 (6513 days ago) @ Ken
Hi Kennith,
To my knowledge, standing waves etc. occur most of the time on the lower
frequencies. The FE-206 rises in volume after approx. 1.2 Khz. Or is this
compensated per EQ? Or do the BD-15 support below 1.2 kHz?
Standing waves and reflections have their influence up to 1kHz, the lower the frequency the more disturbing they can get.
Off-axis (approximately 10 degrees) the FE206E is "flat" from 350Hz up to 15kHz when used in the Quasar, the bass fills in the rest.
The response on-axis can be EQ-ed if you have a reflective room (limited furniture). With a "full" room I would not EQ the driver but prefer to listen to it off-axis. The Quasar as standard comes without EQ.
I've heard that the baffle width also has a possitive effect on the lower freq. response of a full range speaker (positive use of the baffle step(?)
Any driver has a positive effect from a wider baffle but not everybody wants to look at a wide panel. The smaller the baffle the more EQ (or higher Q) the driver needs.
Ciao,
Bert
--
BD-Design - Only the Best!
Quasar positioning
It will vary from listening room to listening room, but what about toe-in with largish dipoles like Quasars? (I'm experimenting with "Quasar-like" "temporary" open baffles with Visiton B200s before I bite the bullet and seriously get into the project) (my "temporary" seems to last a lot longer than many people's "temporary" ... tortoise wisdom tells us that speed is not necessarily a virtue 
)
I'm not keen on listening with full-range speakers pointing directly at my hairy old ears ... a bit off axis always seems best.
I just can't seem to make up my mind whether a positioning with virtually no toe-in gives a more pleasing image / sound stage than a well toed in set up like Niels suggests above. At present my baffles are not toed in, and about 3metres apart (driver centre), and I sit about 3 metres from the speaker plane. Toe-ing in such that the speaker axis crosses over around about 750mm in front of your ears seems to work well with horns and similar ... but what would any of you folk with experience advise with OBs?
Cheers
ALF
A Next Day Edit
I played around with them and the furniture again yesterday after my initial, rather inane, post ...
I have toed them in so the "focus" point is just over 1metre in font of me - this is the most extreme toe-in I have tried ... the stereo image is great! Much more so than before, and the 'sweet spot' is much wider - more choice of seating...
...
... I just don't understand this open baffle thing ... but I certainly like it
ALF again
Quasar positioning
by Bert , Wednesday, July 12, 2006, 00:09 (6505 days ago) @ ALF
Hi Alf,
I must have missed this post, I need a Holiday!
I'm not keen on listening with full-range speakers pointing directly at my
hairy old ears ... a bit off axis always seems best.
With full-range drivers I always prefered to have them pointed to a spot behind me. This brings me more into the musical scene...
If the speakers are not too close to the side walls then you could try that also.
Ciao,
Bert
--
BD-Design - Only the Best!