Woofer with no filter in 2-way works!

[Sony]

Just to share I managed to successfully make a 2-way system with no filter in the woofer.

I thought of this by accident by finding out a spare woofer I was using in a diy 2-way monitor showed a curious response - quite flat and it drops around 2.5KHz at 18dB/oct.
So, I made a 2.8KHz 4th order filter for the tweeter + R (equalization), and got a flat response (+-4dB) from about 80Hz to 20KHz at zero degrees, running the woofers directly to the amplifier without any filter.

I find the midband to be more transparent and natural when running the woofers with no filter and there's plenty of useful midband information up to 2.5KHz, including voices and many instruments. This configuration bonds partially the clarity of a full range with the benefit of a 2-way's high-frequency response, flat up to 20KHz.
Maybe more woofers around may be suitable for this approach (this specific woofer is not a commercial model). To sum up, in my design the sound of 'no filters' in the woofer gets closer to 'being there'.

Rgrds.

[tinitus]

yeah, if you don't play louder than average, it can work ok

I once talked to an older speaker guy
and I clearly remember him saying that it would be best to design the XO to its preferred SPL
half way true I guess

[DBMandrake]

Filter or no filter doesn't matter for the woofer - what matters is what the acoustic roll-off and phase response is. If the driver has a natural roll-off which is just what you want - use that.

If you try to add an additional low pass filter the end result will be the sum of the natural roll off and the roll off of the filter - which will most likely not cross over with your other driver.

Using a textbook electrical filter almost never gives the right result because it doesn't take into account any natural roll off of the drivers.

[18Hurts]

That is a great way to do it if you have a driver that rolls off quickly and smoothly at a desirable crossover point.

The FR guys take the Eminence Beta12 LTA "full range" speaker, install a phase plug and use a single cap on a tweeter filter at around 8 KHz and reports it sounds great. I was pondering the Aurasound 6" woofer at madisound, the 4 ohm version and use a Vifa tweeter with waveguide and a single cap filtered around 7 KHz or so--the charts indicate that nice smooth roll off so no coils required.

Sometimes, less is more.

[norman bates]

don't forget the "gemee audio" tanto. Seems to use the 6.5" silver flute (flattest measuring one) with a single cap on a vifa xt19 (not sure which one though).

The woofer seems to roll at greater than 12db just after 4.5khz.
I got a bunch, they are still on sale (not for long) at madisound.
I'm thinking of ghosting in a hivi rt2h or the vifa, but that will be months away b4 I get to that project.

Another thing to watch for (ghosting in a tweeter) is to make sure the driver's Fs is far far away from the pole you pick. Otherwise the single cap doesn't do much through the Impedence spike at the Fs.

Norman

[phivates]

Probably a four layer voice coil.

[Kjeldsen]

EPOS ES14 have done this comercially with success.

I have heard it very shortly with accoustic music, and it was really breathtaking.

[sofaspud]

The infamous RS Minimus 7 rears its head again.

[alspe]

Originally Posted by Kjeldsen

EPOS ES14 have done this comercially with success.

I have heard it very shortly with accoustic music, and it was really breathtaking.

Epos has many speakers that have woofers with no electrical filter. I have owned many models, now using ES14's.

Reference 3A also has it.

[planet10]

I had some Royd A7 that i enjoyed for some time that ran the midwoof FR.

dave