21" up to 200Hz... It will be interesting to hear. I would probably run them up to 100Hz and have something smaller, like a Beyma 12P80nd covering 100 Hz - 300Hz and then continue with the RD75. But if they don't produce much bass the 21" would be wasted. I don't know how deep they go, but let say 60Hz as an example. 60Hz-100Hz would be a waste!
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Good point, but then I don't use my hifi-system for home theater.
I do of course have a home cinema, and the LFE system in that room is closed box systems. Dipoles simply cannot create that physical impact that makes movie soundtracks so entertaining, but the precision and definition of the bass is nowhere near what dipoles can do in my opinion.
I do of course have a home cinema, and the LFE system in that room is closed box systems. Dipoles simply cannot create that physical impact that makes movie soundtracks so entertaining, but the precision and definition of the bass is nowhere near what dipoles can do in my opinion.
I will second that opinion. I've been using dipole bass in my stereo system for years. People are quite surprised at the quality and definition in the bass. Most people I think are conditioned to hearing the thumping of the room.
StigErik,
What would the repercussions of a wider baffle be for the RD75? I currently use 4, DP15 woofers on each side. They are mounted on a 45cm wide baffle that goes from floor to ceiling. I could easily mount an RD75 on one side of the baffle. It would result in a baffle around 50cm.
Thanks
I did do some wide-baffle experiments with the RD-75, also a single-sided baffle. The positive effect was greater efficiency below 1 kHz, actually requiring EQ to tilt the response down, as the measured response tilted upwards almost 10 dB from 1k down to 200. The downsides: very uneven frequency response, a large dip on-axis around 1-1.5k, accompanied by a large peak of-axis. Needless to say - the polar pattern was horrible.
The simple answer is : yes.
Using low distortion drivers is extremely important at low frequencies, and it gets even more important with dipoles. The main factor in keeping the distortion low is to keep cone excursion far lower than Xmax. That means large Xmax, large cone area, multiple drivers... High-end PA drivers are usually designed for low distortion as well.
Using low distortion drivers is extremely important at low frequencies, and it gets even more important with dipoles. The main factor in keeping the distortion low is to keep cone excursion far lower than Xmax. That means large Xmax, large cone area, multiple drivers... High-end PA drivers are usually designed for low distortion as well.
What do you think of this one? RCF - L18P400
Max. linear excursion (mathematical): 8.8 mm
Your 21" seem to have 10mm.
Max. linear excursion (mathematical): 8.8 mm
Your 21" seem to have 10mm.
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I use BMS's 18" drivers (modified 18S430v2, 18N850 and 18N860... http://www.bmsspeakers.com/). I have had them since 2010. They are very good even as stock in an OB, the venting of the VC is silent. Motor of these things is high tech and employs 3 shorting rings. The inductance is very low and Le(x) and Bl(x) are class leading linear (BMS 18N862 was tested on Voice Coil magazine 2/2012 with top scores).
They are waiting for walnut phase plugs in the picture
An externally hosted image should be here but it was not working when we last tested it.
B&C also makes nice woofers, they have also been tested on the Voice coil (propably 3 or 4 different models, all performing pretty equally, BMS is propably better). One can get free student internet subscription to the Voice Coil...
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"Maximum Displacement, Xmax *** 10 mm"
"Xdamage (peak to peak) 55 mm"
http://profesional.beyma.com/ingles/pdf/21PW1400Fe.pdf
What am I missing? I am trying to learn these Thiele Small numbers.
I would like to try this out for one channel. I have two 12" JBL, 100dB effectiveness that goes pretty low, probably 50Hz. Not optimum but I don't have more speakers. If I were to connect the two like dipole for one channel, how should I connect them?
Like this?
Red amp+ outout =>
speaker 1 (-) connection =>
speaker 2 (+) connection
Black amp (-) output=>
speaker 1 (+) connection =>
speaker 2 (-) connection
"Xdamage (peak to peak) 55 mm"
http://profesional.beyma.com/ingles/pdf/21PW1400Fe.pdf
What am I missing? I am trying to learn these Thiele Small numbers.
I would like to try this out for one channel. I have two 12" JBL, 100dB effectiveness that goes pretty low, probably 50Hz. Not optimum but I don't have more speakers. If I were to connect the two like dipole for one channel, how should I connect them?
Like this?
Red amp+ outout =>
speaker 1 (-) connection =>
speaker 2 (+) connection
Black amp (-) output=>
speaker 1 (+) connection =>
speaker 2 (-) connection
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