Ultra wide horizontal dispersion cabinet design?

[CZ Eddie]

I'm trying to come up with cabinet designs that will provide ultra-wide dispersion on the horizontal plane.

This will be a mono-coaxial driver enclosure. Placed in between a couple of electronic darts machines at a local pub.
The only boundary enforcement will come from the wall directly behind the speaker and from the large dart board machines flanking it on either side.
Otherwise, this is just playing out into a HUGE, wide open bar room.

Thankfully, it'll only be for the darts folks in the immediate vicinity. Such as within 15' max, but from all sides.
Not directly in front of the speaker. As there are five darts machines.

The audio portion will be mostly for listening to live sporting events on the TV.
But occasionally it'll need to handle someone's rock/techno/other MP3 music files delivered over Bluetooth via iPod or whatever.

The driver budget is $20. And the amplifier budget is also about $20. So this is DIY all the way.

Here's the AMP I'm considering:
"12V 60W Hi Fi Stereo Digital Audio Power Amplifier Volume Tone Control Board Kit"
http://www.ebay.com/itm/12V-60W-Hi-F...-/301029437405


Here are a few speakers I'm considering:

"GRS 8FR-8 Full-Range 8" Speaker Pioneer Type B20FU20-51FW"
GRS 8FR-8 Full-Range 8" Speaker Pioneer Type B20FU20-51FW | 292-430

"Goldwood GW-8004 8" Coaxial Speaker"
Goldwood GW-8004 8" Coaxial Speaker | 290-378

"Lowell Model 810 dual cone whizzer 8"
Lowell 810 Speaker Drivers


So far, I'm considering a Karlson Klam or possibly a JBL Scoop.
What do you guys think? Is there a better design out there?
Max dimensions will probably be 48" tall, 11" wide, 20" deep.

The $ budget for speaker & amp is not mine to set.
But the woodworking is my hobby and I'm okay at it. Not scared of challenges. Been there, done that.

[CharlieLaub]

Unless you are designing a horn, it's more determined by the drivers than the cabinet...

If you use smaller diameter (e.g. 4"-5") "fullrange" type drivers, you can just plop them in a shallow cabinet and use the rest of the space to augment the low end with a larger driver. The smaller driver will have good dispersion, and the larger one will fill in the bass.

If you want to use a single driver, you could think about a t-line. This is a very nice sounding one:
The Metronome

[xrk971]

If you want wide dispersion go with smaller drivers as 8 in full range will 'beam'. With that said, if you put it in Karlsonator cabinet the dispersion will be improved.

My suggestion is to go with a dual Vifa TC9FD in a 0.53x Karlsonator. Drivers will be $20 to $24 a pair. For the amp, I suggest the TPA3116D2 - amp is $15. Both of these have their own extensive thread so check it out. The 0.53x Karlsonator with those drivers can get pretty loud as they are now 91dB efficient at 2.83v. I have driven them up to 14 volts rms (about 50 watts which is 105 dB) and it is loud but without distortion. The dispersion has also been measured and is very uniform and wide - almost 90 deg.

The 0.53x Karlsonator hits 60 Hz easily and sounds very even and works for all kinds of music.

[CZ Eddie]

Thanks for the quick & good responses, guys!

Originally Posted by CharlieLaub

Unless you are designing a horn, it's more determined by the drivers than the cabinet...

If you use smaller diameter (e.g. 4"-5") "fullrange" type drivers, you can just plop them in a shallow cabinet and use the rest of the space to augment the low end with a larger driver. The smaller driver will have good dispersion, and the larger one will fill in the bass.

If you want to use a single driver, you could think about a t-line. This is a very nice sounding one:
The Metronome

I do like horns.
I'll have to google the Metronome some more. At first glance it looks a bit wider than I'm able to go, but I haven't yet seen the actual dimensions or any build plans.

Originally Posted by xrk971

If you want wide dispersion go with smaller drivers as 8 in full range will 'beam'. With that said, if you put it in Karlsonator cabinet the dispersion will be improved.

My suggestion is to go with a dual Vifa TC9FD in a 0.53x Karlsonator. Drivers will be $20 to $24 a pair. For the amp, I suggest the TPA3116D2 - amp is $15. Both of these have their own extensive thread so check it out. The 0.53x Karlsonator with those drivers can get pretty loud as they are now 91dB efficient at 2.83v. I have driven them up to 14 volts rms (about 50 watts which is 105 dB) and it is loud but without distortion. The dispersion has also been measured and is very uniform and wide - almost 90 deg.

The 0.53x Karlsonator hits 60 Hz easily and sounds very even and works for all kinds of music.

I forgot about beaming. Thanks for bringing that up.
Have *always* wanted to build a Karlsonator. I may have to go that route!
The Vifa are just barely in budget, so do-able.
But with the small drivers, were you able to get decent midbass at 105db?
I know the Karlsonator is reputed to have tons of midbass, but that was with larger drivers.

EDIT: I found your build thread and will check it out!
Mini Karlsonator (0.53X) with Dual TC9FD's

[xrk971]

Plenty of mid bass. See measurement.

[CZ Eddie]

Hahah, I edited my post just as you replied. Thank you.
I am excited about reading that build thread!

[sreten]

Hi,

$20 for the driver, $20 for the amplifier and you want
to drive a large (huge) space with wide dispersion ?

You need a serious reality check. A tall multidriver column
is what is needed to beam vertically giving better throw.
You will need a lot more power. A double column with
a 60 to 90 degree front baffle if on axis is not wanted
as stated. Minimum is just two angled drivers, but
they will have very poor throw, and won't work well.

rgds, sreten.

[CZ Eddie]

Originally Posted by sreten

$20 for the driver, $20 for the amplifier and you want
to drive a large (huge) space with wide dispersion ?

Yes, the room is quite huge.
BUT, the intended audience are all within 15' of the speaker.
With the majority being within 10'.
We do not care about anything outside of the 15' target area.

Originally Posted by sreten

A tall multidriver column
is what is needed to beam vertically giving better throw.

Vertically?
The intended audience are either standing up or sitting on tall bar stools.
So vertical target is maybe 30 degrees at between 4.5' and 6.5' above ground. Not much to worry about there.
Horizontal audience target area is about 5' - 15' from the speaker, with the sweet spot being 7' distance from the speaker and about 10' wide.

I don't think we'll need clean 105db at the 15' mark.

[sreten]

Hi,

There is no middle to 5 darts machines an the best option would
2 speakers between 1&2 and 4&5. Forget hifi stuff, this is PA.

Two columns using these is probably your best bet :
4" Paper Cone Midrange Speaker 8 Ohm A0100008FP06DA-C | 289-133

8 per column wired for 4 ohms will work with a 20W / channel T-amp.
The Lepai amplifiers spring to mind. 8 should give about 100dB/W,
and good throw, i.e. apparently even more at a distance.
Sealed column, well stuffed, about 0.4 cuft internal for 8 drivers.

rgds, sreten.

Some advantage to rolling off the input of the amplifier, say
-3dB at 150Hz to 250Hz by increasing the input capacitor.
Needless to say mount the column center at ear height.

If you don't understand how columns work I suggest you read up.
Control of vertical dispersion gives greater throw with wide horizontal
dispersion, look at the sound systems in train stations. The throw
collapses at wavelengths longer than the speaker is tall, so there
is not point trying to attempt any real bass, it simply won't work.

Hence the to a hifi person the high Fs and Qts of the suggested driver,
might seem very wrong, in reality for 32" column they are near ideal.

[sreten]

Originally Posted by CZ Eddie

I don't think we'll need clean 105db at the 15' mark.

Hi,

True, but you haven't a hope in hell of achieving that and
have no idea about the coverage characteristics of PA stuff.

rgds, sreten.