Bass Horns...... How come so small?

[Mikett]

I remember many many years ago when I read some AES papers and came to the conclusion that bass horns had to be very large to support the long wavelengths. Witness the Klipshorn etc. that actually need a room wall to extend the horn.

Now I am seeing all these posts about W bins that are actually quite small. Surely these don't go very low and are only good up to midbass frequencies at best or am I missing something?

[Richard C]

You aren't missing anything, the laws of physics haven't changed recently.

A small bass horn is a contradiction and IMO the idea of an in-car bass horn....

[sreten]

Originally posted by Mikett
I remember many many years ago when I read some AES papers and came to the conclusion that bass horns had to be very large to support the long wavelengths. Witness the Klipshorn etc. that actually need a room wall to extend the horn.

Now I am seeing all these posts about W bins that are actually quite small. Surely these don't go very low and are only good up to midbass frequencies at best or am I missing something?

W bass bins are designed for stacking and achieve genuine bass
extension when usen in closely coupled stacks. A single pair is
a poor design solution, 4 or 6 a side is a different proposition !

sreten.

[Mikett]

I understand that stacking creates mutual coupling that increases the effective efficiency. However, when stacked, the coupling starts at a fairly high midbass frequency thus the 3dB gain still doesn't kick in to augment the low end rolloff. I could see staggering every 8 feet or so might get you a little extra extension but with the horn rolloff this is minute.

I suspect these W bins are strictly midbass boxes at best, stacked and cranked to pound chests with high levels of midbass.

[sreten]

Originally posted by Mikett
I understand that stacking creates mutual coupling that increases the effective efficiency. However, when stacked, the coupling starts at a fairly high midbass frequency thus the 3dB gain still doesn't kick in to augment the low end rolloff. I could see staggering every 8 feet or so might get you a little extra extension but with the horn rolloff this is minute.

I suspect these W bins are strictly midbass boxes at best, stacked and cranked to pound chests with high levels of midbass.

The stacking increases the effective mouth area and thus
extends the low frequency cutoff point. Add the extra
efficiency from mutual coupling- which is less with horns
than conventional drivers but still significant and you
can see why a stack of six start to really kick some bass.

Proper W bins designed for stacking appear to have a flare rate
and length out of proportion to the mouth area, consequently
they are far too big for the performance they offer used singly.

But when used in large stacks there is nothing to touch them.
They are only built seperately to allow ease of transport.

sreten.

[OMNIFEX]

With W Bins, it takes 8 Bins to make a 40Hz Horn. If I
remember correctly, 4 Bins will give you a 60Hz Horn.

One of the reasons, why I never recomend anyone
to use 2 W Bins, or, e Horns (Cerwin Vega 36 Series)

They just won't deliver the goods. However, if you're
into midbass.....................


Actually, IMHO, 2 W Bins, or, e horns sound horrible.

I would much perfer using two Double Fifteens, or
Eighteens.

I guess its a matter of what are your requirements,
and/or the type of bass you're trying to replicate.

[mikee12345]

A small bass horn is a contradiction and IMO the idea of an in-car bass horn....

well see it and weep , i get 100db /2.8v/1metre in my room from my CHEAPIE 8" 40hz horn

I live in a house,with no room for 10,000L infinite horns...

il take a picture of it in my trunk/boot.

it is loud!



Basshorns are all about compromise. Those classic huge monsters are using the old math=when one must make the largest horn as to be sure it works

Now we have mcbeans hornresp - and it can show what happens when you shorten,or small mouth a horn

Its a matter of what compromises you want to make

For my 30hz expo horn for HIFI,its a matter of dropping efficiency slightly and gaining some low end...by being triky and getting some ripple.

i get ripple above 70hz-which doesnt matter if i filter sharply.

If one makes informed decisions,its no problem.


Cheers!

[OMNIFEX]

You forgot to mention you are using an 8 inch driver,
versus an 18 inch driver.

With todays technologies you can have a 8 inch driver
with the same Xmax as an 18 inch woofer. The 8 inch
requires less space than a 18, so, you have more room
to extend the length of the horn. In the golden days,
an 8 inch woofer couldn't hold a candle to an 18 in terms
of excursion. So, there was no other choice than to use
a 15, or 18 inch driver.


A W Bin box is ruffly 48 inches tall, 24 inches wide, and
24 - 48 inches in depth. Imagine building a bass horn
out of the 48 in depth box. Oh Yeah! they did, The LAB
Sub.....

[gjeff80]

Omni,

When you stack the W-Bins, are they made to be standing up, or laying doing? Should the 48 Length be from the floor to the top, or running parallel to the floor, so the height of the cabinet would only be about 24 inches? Does it matter which way you position them?

I know the JBL specs for their 18 W-Bin says it should be use in an array of 8 to give horn loading down to 40Hz. But, they say it is designed to be used in multiples of more than two.

Also. how would it work if you laid them in front of the stage? You know the 6 I have from my other post, what would you recommend for a configuration? Typically we used to just put two on each side of the stage, w/ the remaining cabinets stacked on top of them. Now I have another pair, and was wondering what would be the best configuration. Would it be better to stack them all in one place and make an array of 2x3 high if room permited, or would it work better to have 3 on each side of the stage, and laying them side by side running along the front of the stage?

[mikee12345]

omnifex=ofcourse mine is only an 8"
Ofcourse in the old days only larger subs had the power handling

infact the picture i show you is of a 12" transducer on the horn.

there is no point with having an 18" on a 'small' horn. smaller drivers can be more effective as the subwoofer shoot outs prove-the labsub comes out on top.

gjeff see www.prosoundweb.com for subwoofer arrays.

Cheers