Faital 3FE25 enclosure designed for maximum off-axis response?

[CZ Eddie]

I've got a pair of Faital 3FE25 4ohm 3" full range speakers.

https://www.parts-express.com/faitalpro-3fe25-3-professional-full-range-woofer-4-ohm--294-1103

I'm going to make enclosures for them to install in my garage so I can listen to music while walking around the garage. So off-axis response is a MUST.
Off axis response is more for high end I guess.
But does anyone know if there is a rule of thumb on the midrange/low end to help smooth things out off-axis or is that even possible at all?

I'm open to ported or sealed but I don't think that will matter so i'll probably go ported. Depth and Width must be minimal but I can go as tall as 6' for some of those fancy enclosure designs that require it.

 

[picowallspeaker]

Hi, off-axys is important, why ?
The speaker produces a "cone of sound" and the speakers ( or system of) are two in a stereo system .
There's the fact that our ears are placed by the sides of the head.
The head has a particular form, and there's a distance between the ears so the
subject can detect the position of the sound source by quickly analysing the phase difference and the different arrival time at each ear.

What you want to achieve is a high dispersion ( a large "cone)" but this fights with the beaming behaviour of the higher frequencies.
Oh, it doesn't matter !
But this has nothing to do to what happens to the backwave ( i.e. the acoustic load > kind of box if any ) since we are interested in the forward emission, and off-axys response is a part of that. Just don't put any obstacles at the sides of the speaker...

 

[GM]

Hmm, not sure what you're asking, but a driver doesn't begin beaming until ~Fs*16pi, collapsing to ~90 deg at 32pi with breakup modes setting the polar response higher up, so with this tiny driver 'setting' on the baffle till around 5500+ Hz, mounting it as shallow as practical or in-wall is desirable with the more open the wall/baffle area the better to maintain this half space radiation to a much lower frequency.

If you want it to be > ~90 deg higher up, then either multiple drivers/speaker or an omni concept baffle/phase plug will be required. FWIW, shop speakers are normally placed high up and angled down to maximize its coverage area and if the ceiling isn't too high for sufficient loudness, then soffit [and preferably corner] mounted is the way to go.

GM

 

[xrk971]

The answer is simple: mini Karlsonator 0.40x scale will give you beautiful rich sound with bass down to 80Hz with no BSC needed. The Karlsonator aperture provides almost perfect off axis response by performing an acoustic lens dispersion.

Here is link to plans for 0.40x K'nator:

http://www.diyaudio.com/forums/full-range/239338-mini-karlsonator-0-53x-dual-tc9fds.html

Here is an example of polar for a similarly sized 3.5in driver behind Karlsonator aperture in XKi:

You could also make an XKi with it. I would have to run a simulation to determine box dimensions though. But Karlsonator is a proven winner.

 

[picowallspeaker]

The answer is simple:

Just don't put any obstacles at the sides of the speaker...

Does the karlsonator box meet this requirement ?

 

[xrk971]

Does the karlsonator box meet this requirement ?

The aperture is the new "radiator" and thus has only a flat baffle it is emanating from. So no sides to the radiator. There are of course side walls on the original radiator - but the K reformats it.

 

[picowallspeaker]

OMG ! I sweared to myself that I would never open again any topic containing the world karlson, I failed again...!

 

[GM]

Since IME all 'FR' drivers we tried using a DIY 1955 K15 started to sound 'off' above ~250-500 Hz, I never recommend it plus it didn't hold the ~140 deg super wide pattern over a long distance, which wouldn't in theory be very far with such a small cab, so curious to see a realistic shop distance outdoor ground plane measurement.

GM

 

[CZ Eddie]

Hi, off-axys is important, why ?
The speaker produces a "cone of sound" and the speakers ( or system of) are two in a stereo system .
There's the fact that our ears are placed by the sides of the head.
The head has a particular form, and there's a distance between the ears so the
subject can detect the position of the sound source by quickly analysing the phase difference and the different arrival time at each ear.

What you want to achieve is a high dispersion ( a large "cone)" but this fights with the beaming behaviour of the higher frequencies.
Oh, it doesn't matter !
But this has nothing to do to what happens to the backwave ( i.e. the acoustic load > kind of box if any ) since we are interested in the forward emission, and off-axys response is a part of that. Just don't put any obstacles at the sides of the speaker...

What?

Hmm, not sure what you're asking, but a driver doesn't begin beaming until ~Fs*16pi, collapsing to ~90 deg at 32pi with breakup modes setting the polar response higher up, so with this tiny driver 'setting' on the baffle till around 5500+ Hz, mounting it as shallow as practical or in-wall is desirable with the more open the wall/baffle area the better to maintain this half space radiation to a much lower frequency.

If you want it to be > ~90 deg higher up, then either multiple drivers/speaker or an omni concept baffle/phase plug will be required. FWIW, shop speakers are normally placed high up and angled down to maximize its coverage area and if the ceiling isn't too high for sufficient loudness, then soffit [and preferably corner] mounted is the way to go.

GM

Good tips!

The answer is simple: mini Karlsonator 0.40x scale will give you beautiful rich sound with bass down to 80Hz with no BSC needed. The Karlsonator aperture provides almost perfect off axis response by performing an acoustic lens dispersion.

Here is link to plans for 0.40x K'nator:

Aww heck, thread over. Thanks.
I've been waiting for a good opportunity/excuse to build a karlson for a few years now. I guess this will be it since this is far from a critical application and I can play with it!

I'll check out that thread now unless someone can point me to a BOM/build guide/cutlist?

 

[freddi]

fwiw I thought K15 sounded pretty good with my 604 - good with Nirvana Super10

here's an 18" speaker (EVM18B) in a K with generic Eminence crossover and a slotted pipe tweeter from the 1960's Karlson "X15" - it sounds better than some of my FR and has pretty good bass dynamics. -

use headphones

https://www.youtube.com/watch?v=XYsdJZA7coE

 

[xrk971]

Aww heck, thread over. Thanks.
I've been waiting for a good opportunity/excuse to build a karlson for a few years now. I guess this will be it since this is far from a critical application and I can play with it!

I'll check out that thread now unless someone can point me to a BOM/build guide/cutlist?

Well thanks for agreeing so quickly. You won't be disappointed the 0.40x K'nator with 3FE25 is a real gem. There's a reason that thread has over 300k views - they sound great! Plans for 0.40x are linked in the first post.