Horn questions....

[lpd]

I am working on a three way using a midbass horn with a 2461 mid and 2405 slot. Eventually there will be a sub as well, but for now the mid bass horn goes low enough to satisfy my tastes. I have a couple horns that I am experimenting with the 2461 driver. One is a Community/Rauland BRH-90 and the other is a SFA/San Fransico Audio horn very similiar to the 2345 horn used in the 4663 cabinet. Any thoughts on which would work better. The bas horn is using a 12" driver down to 80hz safely although I can squeeze 55 on a pinch :) I am thinking of crossing it at about 800hz. Does this seem right?

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Thanks,

Peter

[spkrman57]

80hz to 800hz is a stretch. If the bottom end did not have to go down that far then the top end response is easier to meet.

Say you used 100hz for bottom end then 800hz is easier to get to.

My Edgar midbass horns I have used are the 80hz and I crossed over at 500hz to midrange horn.

I have changed the last horn I bought from Bruce and went to with 100hz short horn to reach to 800hz. Bruce thought it was just close enough to make it.

As you try and reach lower in your horns, the upper level suffers.

I have subs and don't mind midbass units that only reach down to 100hz.

Your requirements might not be as demanding, but remember horns are only good for so many octaves of duty before distortion or reduced output start eating away at the premium performance.

Ron;)

[hapy._.face]

This is new audio territory for me- so don't quote me until some of the other guys have a chance to correct what may be wrong. I think I'll take a crack at it though :bouncy: :



Since the relationships between compression drivers and transducers tend to be enigmatic- my thinking is to get the maximum amount of octaves overlapping between the two. This way- you can try for a first order XO point. This should yield better coherence. Yes? Trying to push a compression driver to the ends of it's range will demand a steeper order and might result in an audible interruption of frequency when contrasted against a transducer. Short version- don't push the midbass horn too low. Allow stability in the XO point. Go low order, if you can.

Just my opinion- I am in NO way an expert. :p

[lpd]

80hz to 800hz is a stretch. If the bottom end did not have to go down that far then the top end response is easier to meet.

Say you used 100hz for bottom end then 800hz is easier to get to.

My Edgar midbass horns I have used are the 80hz and I crossed over at 500hz to midrange horn.

I have changed the last horn I bought from Bruce and went to with 100hz short horn to reach to 800hz. Bruce thought it was just close enough to make it.



Ron;)

I am looking to use the midbass horns for bottem and mid for now until I can fabricate a sub. I was thinking of cutting the midbass horn off at 500-700hz but am not sure where to cut off the 2461 to the slot tweeter? Any ideas where to top it off?

[hapy._.face]

Quote:snip...'not sure where to cut off the 2461 to the slot tweeter? Any ideas where to top it off?'

Well, it's gonna be steep 3rd or 4th order min. You only have about 1 octve between the two. Shoot for a linkwitz riley (24db slope) at about 10K- giving you roughly 1/2 octave stability either diection.

Based on these specs:
The 2405 slot has a range of 6500Hz-21.5KHz.
The 2461 horn/driver has an approx range of 800Hz-14KHz.
The 12" Driver loaded bass horn has a range of 80Hz*-"?".

*Correct me here: is the 80Hz the top end of your bass (with capability to go lower)?, or is this as low as she goes?
In short: What is the full range of your current bass setup?

[yggdrasil]

If the 2461's still have the phenolic diaphragm's I would cross over as low as possible. 7KHz would be approximately as low as the 2405's will go.

I had phenolics in my LE85's earlier, and was not pleased with the higher frequencies.

[spkrman57]

What kind of power are you running on this setup? I would run the midbass 100hz to 800hz and try it out.


You said:
"
I am looking to use the midbass horns for bottem and mid for now until I can fabricate a sub. I was thinking of cutting the midbass horn off at 500-700hz but am not sure where to cut off the 2461 to the slot tweeter? Any ideas where to top it off?
http://audioheritage.org/vbulletin/images/statusicon/user_offline.gif http://audioheritage.org/vbulletin/images/buttons/report.gif (http://audioheritage.org/vbulletin/report.php?p=92315)
"


What is the HF rolloff of the 2461??? I would say you might squeeze to 7 or 8khz if the horn/driver will allow it. I am not familiar with the 2461, so hard to say.

Hope this helps,

Ron

[Hoerninger]

Hi,

JBL describes in "Tech Note Volume 1, #24: JBL's New Maximum Output Midrange/Low Frequency Transducers" in part "Applications, horn loading" found at
http://www.jblpro.com/pub/technote/tn_v1n24.pdf
the upper and lower frequency range of a cone tranducer.
If you apply the appropriet Thiele Small Parameters found at
http://www.jblproservice.com/pdf/Thiele%20Small%20Parameters/Theile%20Parameters.pdf
you will see, that more than 500 Hz is hardly to obtain with an 12" transducer, which is pointed out by Bruce Edgar too.

If you are satisfied with a restricted directivity at the crossover frequency then it might work.

The more detailed theorie on horns you can find at the web site of D.B.Keele, jr:
http://www.dbkeele.com/PDF/Keele%20(1977-05%20AES%20Preprint)%20-%20LF%20Horn%20Design%20Using%20TS%20Paras.pdf


kindest regards
Peter