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Multi-Way Conventional loudspeakers with crossovers

3-way deliberations
3-way deliberations
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Old 4th July 2017, 07:27 AM   #21
4real is offline 4real  Netherlands
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..disc.. what disc

Anyway, all your talking about are actually compromises..
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Old 10th July 2017, 06:04 PM   #22
LineSource is offline LineSource  United States
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Example passive crossover for MW19P-4 and SB29RDC-4 illustrates how the -12db sealed box roll-off can combine with a LR2 passive L-C to approach an LR4 match with the active bi-amped woofer crossover. A modest cost first pitch?

Flat Baffle model = 11"W * 17"H with 1" edge radius plus a 1" offset on the tweeter.
Xover Model: LR4 @1650Hz and LR2 @150Hz
Sealed volume = 0.33cuft Fsc=84Hz Qtc=0.7
-----
Sealed box volume for MW19P-4 can be adjusted from:
0.33cuft Fsc=84Hz Qtc=0.7
0.58cuft Fsc=68Hz Qtc=0.577
0.9cuft Fsc=58Hz Qtc=0.5
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Old 10th July 2017, 06:15 PM   #23
4real is offline 4real  Netherlands
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Originally Posted by LineSource View Post
A modest cost first pitch?
Thanks! But a cost first pitch would actually entail no passive crossover. I already have all the stuff to make it active Still, very useful information for the active filter configuration.

I would not want to spend more than 10 litre on the MW19P-4 or MW16P-4/MR16P-4. I'm now thinking about making a Beolab 9/20 inspired design. Looking into that via this topic: Cloning a $3200 Speaker for $400 . Since we'll need a fairly low crossover point it will probably look more like a Beolab 5/9 hybrid. The lower platter of the tweeter lens should be a bit bigger than that of the 5. In contrast this will be complemented by the bigger mid bass (the 9 only has a 5" I think), so I guess looks won't be compromised that much.
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Last edited by 4real; 10th July 2017 at 06:37 PM.
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Old 11th July 2017, 10:23 PM   #24
LineSource is offline LineSource  United States
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Quote:
Originally Posted by 4real View Post
I already have all the stuff to make it active .
--Great! Then it would be a very modest cost for you to build a backup reference TM that matches your Rythimic woofer cabinet.
--If you are planning to experiment with either the MW19P-4 or SB29RDC-4 for your Beolab 9 ideas, a reference TM box is worth consideration.
--Organic Shape: cabinet shapes for the TM like a round-arch is one of my favorites... show your wife
--BOX: (12l total internal volume, 9l sealed mid volume, cabinet. 2x thick flat baffle = 11"W * 17"H with 1" edge radius plus a 1" offset on the tweeter.)
===
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Originally Posted by Patrick Bateman View Post
I like tinkering with SAW Lens because I like tinkering, but if you just want a good reliable solution, the recipe below is as good as I've seen:
1) oblate spheroidal waveguide with the entrance angle of the waveguide matched to the exit angle of the compression driver
2) asymmetrical mouth to minimize the on-axis dip that symmetrical waveguides exhibit
3) Significant roundover at the mouth of the waveguide or on the baffle of the loudspeaker
Do those three things and you end up with a real world beater, significantly higher fidelity than any horn I've ever used. It's a formula that just works.
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Old 12th July 2017, 10:37 AM   #25
4real is offline 4real  Netherlands
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That is actually not a bad idea. Maybe something like this: Oval waveguides? - Techtalk Speaker Building, Audio, Video Discussion Forum

Click the image to open in full size.
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Old 16th July 2017, 06:29 PM   #26
LineSource is offline LineSource  United States
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Have you made the decision to build a TM speaker similar to this PartsExpress design?
= dome tweeter in directivty controlled shallow oval waveguide + sealed midbass + cabinet with rounded arch top
--------
You may find this time step data helpful for your waveguide:
TW29 tweet vs MW16P mid = 61us = 21mm
TW29 tweet vs MW19P mid = 93us = 32mm
SB29RDC tweet faceplate is 1.7mm thinner than TW29 faceplate ~5us less delay
-------
-With DSP, a calculated depth waveguide is not required for T-M time alignment.
-The T-M center-to-center distance should be short ( 4.1" = 1650Hz half wavelength).
---You can trim the tweeter faceplate to get <5" C-to-C on a flat baffle.
-So, flat baffle with DSP T-M crossovers @1650Hz has: single lobe, good step response, and constant power.
i.e. waveguide offers tweeter pattern control, BUT DSP sound on low diffraction flat baffle should also please
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Old 18th July 2017, 02:10 PM   #27
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No, have not made up anything yet. Still exploring options

Another nice design we like is the Focal Utopia stuff. They are quite chunky, but look really nice. I could imagine replacing the tweeter section with a 60x40 horn, with the MW19P on top, and the Rythmik stuff below.
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Old 28th August 2017, 01:19 PM   #28
4real is offline 4real  Netherlands
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.. exploring some more ..

Well, I did come to something completely different: A Synergy horn. While spending the last couple of weeks reading up on the subject and thinking about a possible setup I came to the following:

90x60 horn, that should be used full range, or at least be able to play down to about 30 to 40 Hz (this can be achieved by active correction). Tweeter and mid will be fulfilled with the BMS 4590 coax. We're then left with a woofer to cover up to 500~600Hz. To get a bit of output down low I'd like to use two 10" woofers. That should just about fit in the horn. Now the question is what woofers to use. I tried a few and came to this shortlist:

- SB29NRX75-6
- Peerless SLS10
- Beyma 10BR60V2

They all provide quite a bit of extension according to my Hornresp simulations. I don't quite get the MaxSPL calculations though. It looks like the Beyma can do about 3dB more at 20Hz than the SB (107 vs 104dB), while the SB has the bigger Xmax. I always though that down below Xmax is the most important figure for maximum output (SD being about equal). WinISD also does not seem to conform to this (used closed box model). The peerless probably gives the most bang for buck. It's cheap has a fairly good reputation.
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