Using 2 identical full-range drivers per speaker

Hi,

Im new to speaker design. I’m looking into using 2 identical full-range drivers on the same ported speaker box. I’ve seen a design where the 2nd driver just runs as a low frequency driver (using a filter). Would it be possible to have both drivers running full range, would that be advised/make sense? Thank you
 
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Yes, using more than one at higher frequencies is best avoided unless you have a good reason to do it.

Using the second for bass (actually baffle compensation) is a good idea, as Dave shows. Use the lower circuit if you use a regular amplifier.
 
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frugal-phile™
Joined 2001
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comb-filter-diagramX.gif


dave
 
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Well, at least you know what you are getting into, I did not.

Can you step up to a 5-6" ?

I had luck with 4 x 3" tg9 drivers frame to frame.
At 10', keep your ears between the top and bottom drivers though.
At 16', you could be a bit above the top driver....................
 
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addendum: I've done this with three pairs of the same alnico 6x10 vintage drivers using both baffle-step low-pass inductor and side-firing mid units; high units open-baffle. Right this minute, I'm listening to 5&10 (five-and-dime) Markaudio MAOP5(gen1) OB in series with side-firing Alpair10(gen3), kind of bipole configuration. I rescued the damaged 5 yesterday from "idle-fishmarket"; the experiment sounds... jaw-dropping.

Screenshot_20231024_201850_com.taobao.idlefish.jpg
 
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frugal-phile™
Joined 2001
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and use a shunt capacitor (about 1.5 uf seems enough)

It really needs to be bigger than that. 1.5µF on an 8Ω driver will be above the midrange.

Using the nominal bafflestep -3dB as a staring point then: C = 1 / 2∏Rdriverfbs.

4Ω driver at 500 Hz is an 80µF cap.

And it should be below the quarter wavelength of the centre-to-centre of the drivers.

dave
 
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Not in this physical reality.

It can work insofar as you can (can) run twin small wideband drivers unfiltered, but how well it works it depends on the on / off axis response of the drivers, their spacing and the listening position relative to them. To put it another way: there will always be some destructive interference. It's just a question of how much / how bad it is. Without knowing what the drivers are, this is all pure speculation.