Which Horn for linear response down to 20Hz?

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Magnetar

Magnetar

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Joined 2004
RobWells said:
:cool: Those main horns make the screen look small ! How big is it ?


What are your feelings on eq'ing horns below the cutoff ?


Rob.
Click to expand...


Back then I used a 7' 4:3 screen - now I use narrower speakers and built a 10' screen.

I believe if you build a horn for the deep bass you should use the room to it's full advantage - 1/8th space loading (corner) is a big plus and normally will use up less living space. Eq is fine as long as you don't over drive the driver and expect miracles with too small of a horn. My triple subs use a lowpass single pole lowpass at 30 cycles built into the front end of the bass amps. The JBL 2242's in the three horns have a combined sensitivity of around 112 db/W/M at 20 cycles. They are AWESOME basshorn drivers! I use 220 watt watts/ three channels with a mono input to all three horns, plus use a Paradigm X30 with variable low pass and 0 to 180 degree phase adjustment infront of the amps to fine tune to the main speakers. It will reproduce a thunderstorm with little to no compromise. It can be scary - the air pressure in my room can be overwhelming.
 
A

AndrewT

R.I.P.
Joined 2004
Hi Magnetar,
I have asked this question before and appreciated the feedback but I would like to hear your opinion.
How long are your horns?
The bass horn is very long and this effectively delays the bass signal. You mention a continuously variable phase control on the bass horn? Does this appear to bring the bass signals back in time with the main speakers or does it just avoid the suck out around the crossover band? with the resultant slow bass because all the main speaker signals arrive waaay ahead of the bass?

Hi all,
If I use an 18 inch driver in the sub-bass horn 6m to 7m(20 to 25feet) long driving a 3.6sqm (42sqft) mouth into the corner of a 160cubm (4500cubft) room will I get some room gain at very low frequencies? I think I will have a lot a spare capacity in power and volume terms, so does that mean I can apply a linkwitz transform to pull up the low frequency response for AV use? For music I will settle for a response down to 20 Hz.
How do you adjust Linkwitz to take account of room gain? Trial and error or something more technical?
 
DeonC

DeonC

Member
Joined 2002
Hi guys

I thought you might enjoy this: a picture of a pair of Jensen Imperial horns with a Hartley 24" driver in each! :bigeyes: :bigeyes: :bigeyes: Now that ought to get you real low with real ease!! :cannotbe: :D

Enjoy,
Deon
 

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Magnetar

Magnetar

Banned
Joined 2004
AndrewT said:
Hi Magnetar,
I have asked this question before and appreciated the feedback but I would like to hear your opinion.
How long are your horns?
The bass horn is very long and this effectively delays the bass signal. You mention a continuously variable phase control on the bass horn? Does this appear to bring the bass signals back in time with the main speakers or does it just avoid the suck out around the crossover band? with the resultant slow bass because all the main speaker signals arrive waaay ahead of the bass?

Hi all,
If I use an 18 inch driver in the sub-bass horn 6m to 7m(20 to 25feet) long driving a 3.6sqm (42sqft) mouth into the corner of a 160cubm (4500cubft) room will I get some room gain at very low frequencies? I think I will have a lot a spare capacity in power and volume terms, so does that mean I can apply a linkwitz transform to pull up the low frequency response for AV use? For music I will settle for a response down to 20 Hz.
How do you adjust Linkwitz to take account of room gain? Trial and error or something more technical?
Click to expand...

Hello, what I'm using is three horns combined together side-by-side sharing the same 42 square foot mouth in 1/8th space, because of this configuration the path can be as little as 7' or as long as 21' - it would be very difficult to model, although wizards like John Sheerin that visits this forum could do it.

The phase control does avoid suckout but you have to understand there is three drivers seperated by 13-28' each that span across the whole front of the room which does vary the time and phase at the listening position (and room modes overlap, reinforce, cancel, ect) so it really dpends where you are in the room and where the main bass drivers are. I feel the power, dynamics, articulation and depth with this subwoofer system is worth the paranoia of knowing there is a delay from the mains. I have uses a digital delay on the mains and didn't like it. I normally only run these up to 40-60 Hz.

Corner loading will give you higher output and less ripple in the bass with a smaller horn! It is the way to go if you have solid corners. If you model in the McBean program in 1/8th space compared to 1/4 or 1/2 you will see a pretty good simulation of what the differences are.

I also feel front loaded horns like mine are considerably better sounding than the backloaded horns I have seen posted here. It does however come down to much more than front loaded versus backloaded - IE the Imperial is not relly a horn subwoofer, it is more of a direct radiator with backwave reinforcement in the bass. Probably a better cjoice for someone who wants to crossover above 80 cycles, but not as good for what I want out of my subs,
 
freddi

freddi

Member
Joined 2005
although dB# did not beat expectations/rules , briefly tried a 416 in funky Karlson tuned ~28-30hz per eXemplar w. a couple of pvc elbows - didn't have proper bandpass filter centered @30 as they used - so kluged w. old EV Interface box and a funky k12 w. ancient Allied-Knight-Jensen - maybe good (not "thick") tone was due to low-mass Altec - but played very well on better theatre organ cds with nice decay vs a B6 reflex w. - uh Eminence/Dayton 15 - system ran mono w. thrift store 15W/channel receiver room was only 14x22 - guess lower tuning added ~7-8dB in 20-32Hz then boost another 6 on C note -maybe not what folks would call SOTA but... ducts were not well received on K-forum so it was trashed.

eXemplar sub

An externally hosted image should be here but it was not working when we last tested it.
 
Q

qi

Member
Joined 2003
Bass-Depth said:
Are there plans in this forum for Speakers which are loud enough to play with one or two Tuba 36 also as PA-Speakers but with clean sound like a super Hifi-speaker?
Click to expand...

My two cents...

I would go with the largest TUBA 36 plan with the horizontal (BR) slot option to get into the teens.

I would cross them over (36db active) at 50hz to this DIY design...

http://sparkgap.homestead.com/DIYHedlunds.html

I would use a single high quality capacitor at 4k to HEIL AMTs (or equivalent)
 
Q

qi

Member
Joined 2003
Bass-Depth said:
Are there plans in this forum for Speakers which are loud enough to play with one or two Tuba 36 also as PA-Speakers but with clean sound like a super Hifi-speaker?
Click to expand...

Here is another candidate, and there will be DIY plans posted "real soon"...

http://www.hornloudspeaker.de/

It looks similar to the Carfrae Little Big Horn
 

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