Bamberg Series 3 Speaker

psbfan9

psbfan9

Audioholic Samurai
Series 3 Active2 EQ2 in-room SPL curve at Listening Position


Here is today's EQ result curve in red, overlaying last week's initial EQ attempt (black).


This time I applied a high-pass crossover to the right woofer only. It is HP 2nd order, Butterworth (Q=1), at 35Hz.

What this does is rotate the right woofer phase to 45° at 60Hz, and to 90° at 35Hz. So now they don't interact with the room in such a way as to strongly cancel 55Hz as before, nor do they boost 30Hz as strongly.


So you can see how 30Hz is as level as before (with dual HPF2's on both channels), and yet the missing 55Hz band is filled in better. Note that while I boost 55Hz by 6dB, it responds to the EQ much better than before, since this band is not as efficient at acoustic cancellation. Impressive, since filling in cancellations is nigh impossible.


In summary, I recovered up to 10dB missing output up to almost an octave band in the middle bass with a clever trick called Phase Quadrature.






Bamberg Audio :: Speakers for Life
 
fuzz092888

fuzz092888

Audioholic Warlord
Is this the MTM with Dynaudio drivers? Also, the image isn't working for me.
 
Philip Bamberg

Philip Bamberg

Audioholics Approved Vendor
No, this is for the new Series 3, which is near the end of the R&D cycle. First two pairs are being readied for sale, tour, and reviews.

The image was part of an email I sent out to my inner circle. I post it here now.

These curves are at the listening position, with 41" microphone elevation on the reference axis of the speaker, both speakers driven, 1/12th octave smoothing, 2ms window. There is no room treatment.

30Hz was very hot, and 50Hz very cold. By shifting the phase of the right woofer only with a low-frequency high-pass filter, I effectively "move" the 50Hz anti-node off to the side of the listening position. So now 50Hz will respond to EQ. Without this phase quadrature method, 50Hz remains a perfect cancellation and it wouldn't respond to EQ.

The same holds true for the 30Hz room mode. Since one woofer is 90° phase shifted from the other, they don't sum as high at the node frequency.

Note that the phase relationship of each woofer is unchanged at the cross point to the midrange. So this does not detune the lower crossover in any way.

The alternative (last week's attempt) was the more customary approach of using straight PEQ filter to tamp down 30Hz. But this prevented any attempt to fill in 50Hz.

Now the bass sounds much more solid and with more slam in the middle bass. Just two global EQ filters used, and one additional "crossover" filter on one channel only.

#29_s3_11864_L&R_EQ1&2.jpg
 
psbfan9

psbfan9

Audioholic Samurai
Is this the MTM with Dynaudio drivers? Also, the image isn't working for me.
No, this is the new Series 3. Phil has asked me to not discuss drivers until the 'official' launch.
I'm not sure what happened to the graph, but as you can see Phil has successfully posted it with more info on the design of the new speaker.

Guys, if you're considering new speakers in the future, you may want to take a serious look at what Phil is producing.

Bamberg Audio :: Speakers for Life
 
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