Bass Horn

[Dr.db]

Hey folks,


me and a couple of friends are planing to build a little PA for outdoor use.

The Tops are JBL: 2402,2260 & 2*E-110(frontloaded horn)
The amp for the bass-section is an old and heavy(80lbs) Bose 1800 with aprox. 250.w @8ohms....
The subwoofers shell be running down from 40hz up to 150hz....
Cause of the little power we got the subs must have a very very high sensitivity!!

Im not shure which drivers to use and which enclosure will fit best...? :dont-know
....i thought about using 2226 in the 4530 scoops.
But I recon they wouldn't go deep at all and sensitivity isn't that good too.?!?
The usual sensitivity of the 2226 is 97db. Is it 103db in the 4530 scoop?
How about a 4520 with two E-140 !? Would that be 106db?


Which other horns would be better for my use ?


Thanks a lot for your help!!!
Best whishes from germany,
Olaf

[Zilch]

http://www.audioheritage.org/vbullet...ad.php?t=24695

[jcrobso]

The horn loading tends be a little more efficient than the driver's direct radiation so crossing over at 150 is a good idea. Over the years subs in big boxes have replaced bass horns, mainly because of the size of bass horns.
For the same size box you can get two 18" drivers and get down to 30hz. Horn loading gets you the most db per watt, John

[jbl4ever]

http://www.jblpro.com/pub/obsolete/l...nclosures2.pdf

[Dr.db]

Horn loading gets you the most db per watt, John

So horn loading is the only possible way for me.
Since I got just 250.watts @ 8ohms...


Is there any sense in using old E-140 or E-145 instead of new 2226 ?

These speakers shell reproduce up to ~150hz, above 150hz the E-110 will get
on... So does the 2226 a better job then the E's? Or does a E-140/145 has a higher efficiency ?





Would you guys build a 4530 or 4520 when powering with 250.watts??




Thanks a lot so far!!!
For the links and for the ideas

Olaf

[CONVERGENCE]

Hey folks,


me and a couple of friends are planing to build a little PA for outdoor use.

The Tops are JBL: 2402,2260 & 2*E-110(frontloaded horn)
The amp for the bass-section is an old and heavy(80lbs) Bose 1800 with aprox. 250.w @8ohms....
The subwoofers shell be running down from 40hz up to 150hz....
Cause of the little power we got the subs must have a very very high sensitivity!!

Im not shure which drivers to use and which enclosure will fit best...? :dont-know
....i thought about using 2226 in the 4530 scoops.
But I recon they wouldn't go deep at all and sensitivity isn't that good too.?!?
The usual sensitivity of the 2226 is 97db. Is it 103db in the 4530 scoop?
How about a 4520 with two E-140 !? Would that be 106db?


Which other horns would be better for my use ?


Thanks a lot for your help!!!
Best whishes from germany,
Olaf

The 4520 and 4530 are short throw rear loaded bass horn that become direct radiators above 150hz. Recommended speaker 2205. No sensitivity gain.

The 4560 and 4550 are front loaded horn long throw with a 6db sensitivity boost above 100 Hz. Recommended drivers are 2220 and 2205.

......................................

[Dr.db]

Thank you.


Which enclosure (horn) and driver do I need for sensitivity gain below 100hz ?
....it should be well over 100db/m/w
....Size does not matter a lot

[CONVERGENCE]

Thank you.


Which enclosure (horn) and driver do I need for sensitivity gain below 100hz ?
....it should be well over 100db/m/w
....Size does not matter a lot

None ,only the 4560 and 4550 will add 6db above 100hz.

[Dr.db]

And how much amp-power is ideal for one E-140/145 ?

Sine-Power! ...not music-, peak-power or whatsoever....





Could I simply build the hornmouth of the 4560 aprox. 50-60cm deeper to achieve sensitivity gain from ~70hz instead of 100hz....!?

[subwoof]

The rear loaded scoops *do* add sensitivity - the peak is around 60hz. Look at the JBL graphs ( note the zero line ). the boost is much lower in frequency than the 4550/60


:o)

[Hoerninger]

A bass horn up to 150 Hz should be frontloaded and should have horn support for its lowest part too, no bass reflex.
When driven with a compression chamber the results are improved efficiency and a smoother frequency response.
The response shown below is for a room corner. When driven in front of a wall there is a slight roll off and above 100 Hz increased peaks and lows, but still good for usage. The sound pressure level will be decreased by 3 dB of course.

Just an example which might be possible.
___________
Peter

[Dr.db]

The rear loaded scoops *do* add sensitivity
- the peak is around 60hz. Look at the JBL graphs ( note the zero line ).

How much?
What sensitivity do the scoops have at 60hz eg. 100hz ?

Sorry for asking soo often, but it's quiet important for me to know...



And thanks to Hoerniger for the simulations!!!

[paragon]

Sieh das nicht so eng. Die 4530 geht bei Eckaufstellung bis ca 40 Hz runter. Das Lautsprecherchassis ist hier nahezu egal. Die Lautstärke ist allemal groß genug. Ich habe diese schon in einer Discothek gehört, reicht locker, laut und tief genug. Die 4520 geht noch ca 10 Hz tiefer bei gleichen Bedingungen.
Die 4530 steht bei mir in einem 12 qm Raum in den Ecken. Geht tadellos.

[Dr.db]

@Paragon
Hallo,

die Bassrutschen werden ausschließlich draußen eingesetzt, dort gibt es leider nirgends Ecken...
Ob die Lautstärke groß genug ist....!? sehr relativ...
Ich frage deshalb so akribisch nach dem Wirkungsgrad; denn wenn dieser nicht größer ist als wie bei einer regulären Reflex-box dann muss ich mir beim bauen nicht die Arbeit mit dem Horn machen

Besten Dank & Schöne Grüße,
Olaf


@Paragon
Hello,

the scoops will run outdoors only, there aren`t any corners at all.
If soundpressure will be enough....!? ....quiet questionable...
I`m hanging onto this question(if sensitiviy is higher than Reflex/vented), because if this isn't so, I won't have to spend plenty of time building scoops when bassreflex will have same sensitivity

Thanks alot & Whishes,
Olaf

[Paul D]

This site has some interesting designs for horn subs. I built a lab 12 sub which is a similar design and it had high output to about 30hz. Some of these designs use the 2226 or cheaper alternatives.

www.billfitzmaurice.com