I think the shape is more like this:
(apologies for the poor quality sketch!)
I do find the claim of 7 dB boost from the 'squeeze' surprising, to say the least.
I'm pretty sure the sides are solid all the way up. There are more pictures here which show this: https://steinwaylyngdorf.com/steinway-sons-model-b/
(apologies for the poor quality sketch!)
I do find the claim of 7 dB boost from the 'squeeze' surprising, to say the least.
I'm pretty sure the sides are solid all the way up. There are more pictures here which show this: https://steinwaylyngdorf.com/steinway-sons-model-b/
Fairly consistent with measures of Nelson’s slot loaded woofers. The gain is only near-field.
dave
It is a 4x400 watt amplifier inside. Why so when it is a 3-way speaker?
Maybe it is two closed sections with separate amplifiers who plays time allignede in oppsite polarity?
Maybe it is two closed sections with separate amplifiers who plays time allignede in oppsite polarity?
There are 6 woofers in one speaker. I don't know their impedance of individual, but if they connect parallel, then it is better for an amplifier to drive 3 woofers instead of 6 woofers.
Don't think the woofers are baffled in the center, do not see any such element in the assembly photos. Also, the sides look to be closed. AND the mid diver is a 5 1/4" diameter - not quite large enough to go fairly flat OB down to 350Hz as Linkwitz stated. This implies the designer(s) are correcting all response issues with DSP, and the mid and high frequencies will definitely have issues. The drivers are centered for one, the baffle is wide and lots of diffraction from the sides. Finally, the little 5 1/4' will probably exhibit higher distortion to really handle down to 300Hz. Maybe not a big deal but still...
I'm not absolutely sure what you mean by "baffled in the centre", but I'm pretty sure the Model B woofer baffle looks like the little sketch I put in post #61 above. If you watch the video in post #2, Peter Lyngdorf says the model B has "a zigzag baffle". Watch his hands as he says this. Also he then talks about how this pressure loads the woofers.
The diameter of the mid isn't going to determine how low it can go 'fairly flat' (though it may limit the max SPL). The baffle size will have more influence than the driver diameter, and it's a big baffle.
Anyway SL used an 8" driver down to about 120 Hz in the Orion and the LX521 - with minimal baffle in the latter. Since going an octave lower requires roughly four times the driver displacement, I can't see that 350 Hz with a 5 inch is a huge problem.
But I do agree that the wide baffle looks problematic for mid and high dispersion.
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I am not seeing the zig zag piece that you describe, rather looks like the 3 woofers are mounted to L shaped brackets - nothing in between the two sets. I have measured about 10 different 5 1/4" drivers for an OB application, and none will respond flat to 300Hz without a cabinet or response correction. Alternatively the 6 1/2" ones do easily. However, the larger mids start to get directional at 2-3Khz or so, and the 5 1/4 will definitely go higher and disperse well. I heard Linkwitz's comments, so it is interesting, wish I could see one in person.
Lyngdorf Model B is an active speaker with built in DSP, so there is a response correction here and will easily have response flat to 300 Hz.
Because based on the brands. Lyngdorf is a technical designer because of his audio engineering background. So I guess he will not use 12" woofer cross at 800-1000Hz since the radiation pattern of 12" woofer will be much more narrow than 5" driver at that frequency, and create the mismatch at off-axis.
I think 500 Hz is the maximum frequency for crossover between 5" and 12" driver, but 300 Hz is the worse case in terms of displacement, so we use it as an example
I think 500 Hz is the maximum frequency for crossover between 5" and 12" driver, but 300 Hz is the worse case in terms of displacement, so we use it as an example
Dipole pattern gives constant directivity up to first axial null, which is dictated by width of the baffle (shortest pathlength)
The problem here is that the mid loses dipole pattern too early, there is wider pattern just above 1kHz before the mid starts beaming around 3kHz. Tweeter has similar variating directivity.
The virtue is in enormous bass capacity with low distortion with dipole pattern.
The problem here is that the mid loses dipole pattern too early, there is wider pattern just above 1kHz before the mid starts beaming around 3kHz. Tweeter has similar variating directivity.
The virtue is in enormous bass capacity with low distortion with dipole pattern.
This is from the Installation Manual. It's only a line drawing but it looks to me as if there's a solid piece in the middle between the left and right woofer columns. (And nothing else would make sense frankly.)
The Installation Manual (available on the Strinway Lyngdorf website) suggests that there are two woofer channels dedicated to the woofers, each driving a bank of three woofers. My wild guess would be that they are are the SB34NRX75-16 woofers. If so, parallel connection would give dcr of about 4.67 ohms.
I saw the video now and it’s definitely an open baffle and not two separate chambers. Since Peter Lyngdorf explain the reduction of 2 harmonic distortion and that the separat 3 pairs have reversed polarity the sound wave comes from all 6 woofers. Maybe the 4 channel amp altså fine tune the delay on one of the 3 pairs so all the 6 have equal start point. 6 x 12 inch long stroke dipole woofers is nice 😎 and 60 cm with plus wings give around 1 meter effective baffle. I think it will be no problem to adjust a nice crossover with dsp and Roomperfect with this even if the baffle around the midrange is very (too) wide.
I have made a lot of open baffle speakers and I must say I am very impressed and curious about Lyngdorf model B 👍
This is one of my dipole constructions:
I have made a lot of open baffle speakers and I must say I am very impressed and curious about Lyngdorf model B 👍
This is one of my dipole constructions:
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