Decent midrange driver 250...1500 Hz

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URI55

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Joined 2019
markbakk said:
I wouldn't know why they would not align the mid and high driver. The motors are both on the outside, it's only a matter of moving the diaphragms closer to or further from each other and shaping the compression channels. A lot of other coaxes (Tannoy e.g.) have the problem that the motors are back to back and one has to account for the different acoustic centers.
Click to expand...
I made a measurement :)

Sorry to the OP for OT
 

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freddi

freddi

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Joined 2005
about 40 years ago I had Cerwin-Vega S1 with 12"/6.5" and"dhorm" of 6.5" diameter. - Active 6th order alignment, gas bag enormous fun with a DH200. If things were more favorable these days, I'd do a clone with cheap but cheerful Dayton PA310, Lavoce 97dB 6.5 and try to find a 6 inch round waveguide and run that with a small CD. PA310 would be happy in as little as 34 liter and the narrow band of boost not taxing on its 5mm excursion even at high levels. With a decent crossover this would probably sound better than the S1 for a driver cost per side of less than $200. An old EV Interface RQ box could to the filter/boost.

Cerwin Vega S1 | Audiokarma Home Audio Stereo Discussion Forums


pa310 Sim

https://i.imgur.com/0eG9UxB.jpg
 
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diyiggy

diyiggy

Disabled Account
Joined 2019
Not sure I understand the maths !



Should we not look at the impulses of the picture 2 ? Around 0.5 ms between the top of the two first impulse. I'm not understanding a lot of thing when it comes to phase, etc, but it seems quite good ! I don't know how I would deal with this in a passive filter by playing with the phase or a little pass band to delay the treble (easier with active dsp set ups)... But sure quite good, nothing to see with a Klipsch coax !
 
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newvirus2008

Member
Joined 2008
Isn't that 0.05ms? I couldn't make out exactly how much that was. So I used the phase from the first graph to get to 45us (0.045ms) at the crossover of 6.1k, which is close enough to your 0.05ms. However, the impulse responses showed around 0.07ms (70us) which I used in my second calculation for the physical offset between the mid and treble portions.

In the passive world, a delay is obtained by way of an all-pass filter.
 
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ScottG

Member
Joined 2003
ScottG said:
Is this really (or far closer to) what you want (as opposed to the initial post)?

IF so, dispersion matching is an issue with a smaller diameter mid. and typical horn/compression driver. (..and if you (horn)load the mid then you've got depth offset issues.)
Click to expand...

This should provide the offset for a focal-like design and allow for smaller diameter mid.s for integration at a lower crossover freq. (..around 2 kHz):

Dome tweeter SB Acoustics SB26STWGC-4, impedance 4 ohm, voice coil 26 mm

..and perhaps a "focus'ed" MTM (2x parallel connected) with these:

Boutique Haut-parleurs & Audio DIY

see measurements here:
Timothy Feleppa's Pages: Speaker Measurements - Woofers 5" to 8"
 
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