Mid driver.Fs 173 Hz ???
No Metamaterial in the back?! Return that ASAP. ;-)
Fs 173 Hz ???
OK, just saw this is a unit from the R series - thought it was LS50
I guess my next speaker purchase will be from you and not from KEF . Keep up the good work!@Nusse printed a flare and sent it to me for testing. I'll be making some measurements soon . Plan is to make a test cabinet out of chipboard and measure horizontal and vertical response 0-90 in 10 degree increments and to do some distortion testing.
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Other thing is to figure out how to mount the flare. Should i glue it on to a front baffle and mount the coax from behind or some other way. I guess that press fitting for flare it is out of the question since R series shows problems in that area (flare movement due to continuous usage). Also, a mounting ring must be made for midrange. In 2011 R series coax is mounted directly to the front baffle which is quite thick and it isn't beveled from behind to let the midrange breathe. 2018 R series is made better in that regard:
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In old R series there was an aberration in frequency response at around 1100Hz. How much of it is because of poor driver mounting i really couldn't tell. We'll se how this little fellow measures. So, pace is slow but steady.
It would be interesting to see how large flare could be made and how low can we control the directivity with it. Maybe using a bigger woofer bellow ? Exciting stuff
I guess my next speaker purchase will be from you and not from KEF . Keep up the good work!
The R series concentric driver does not have the long travel surround found in the LS50/Meta. It's designed to go down to around 400 Hz.
Now you're making me blush
I'm aware of that. It has other benefits because it is a dedicated midrange. I'll try to make it down to at least 300Hz. Measurements from Kef R series whitepaper shows very good distortion down to 200Hz at 5.6V applied. That would probably be a no-no but 300Hz is doable. I did it before with R300 and it sounded very good.
Any model or drawing of what the final speaker is supposed to look like?
I see, hope you get a nice result.^This is from existing R series.
@Ron Texas Thanks.
This is supposed to be an exploratory project. I'm tempted to jump to dual woofer W-DC-W first, similar to Reference 3. Since woofers i chose don't need large volume to get down to low 40's i might get away with standmount size. So nothing new here. I am doing measurements with >10ms gate quasi-anechoic, so measurement resolution will be very good. I also intend to try constant radius ports developed by JBL which should hopefully keep the distortion low at bass frequencies.
Ehhh, isn't the goal to be CD down to at least the Schroender frequency, not actually cardioid? Since 90° still has a lot of energy, you don't get the benefit of reduced early reflections, only diminished SBIR.If you choose dual woofers, DSP and at least two amp channels per box, maybe you can try the cardioid dispersion.
It can work with one front and back each, but note the back needs a cascaded xo branch over the front one, not a delay as such since it is already physically distant.
Something like this (simulated as a concept, not actually built, but with actual drivers measurements):
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