B&C 12PE32, what to do with it

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Hello!

I have 2pcs of 12PE32 that at the moment I use in a front loaded conical horn (5400cm2 area, 70cm deep cone). Because I have 2 front loaded Tractrix horns Fc 250Hz that I don't use, I want to switch from conical horn (not so good loading) to something else.

The midbass shall cover 100-400Hz, and the Tractrix horn above 400Hz-3k (loaded with FaitalPro 3FE25 at the moment).

I have checked EBP on this site mh-audio.nl - Home and, with a value of 268, ported enclosure is recommended.
Also B&C recommends a ported enclosure.

Searching with Google on some sites, there are different ideas, that ported for this 12PE32 is not ok, other guys wrote that even sealed works ok..

So the question is, what enclosure type to use for 100-400hz with 12PE32?

Vented, as in the specs (31 liters, tuned to 85Hz)?
Sealed ?? liters?
Tractrix horn? (simulated gives great response but it's a bit too big at minimum 70cm horn length, also considered folded midbass horn, but I am concerned about the quality of the sound with the folds involved..)
K402-horn clone, with the midbass entering on one side?
Live with the conical horn?

I have seen all threads regarding front loaded horns with 12PE32. but somehow I am not convinced that for such small room I have advantages with a bigFLH. What do you think?

Bellow 100Hz I have 2 sealed 12"-subwoofers and a 10"-tapped horn. Crossover is active, using EqualizerAPO.
Room size is 5m/5m.

I will appreciate any idea and reviews regarding 12PE32 usage.
Thanks!
 
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These are good speakers and it's a shame to have good speakers looking for a place if you can't find one. On the other hand you have plenty of performance to sacrifice/compromise in making it fit. What do you want to get out of it, sub-vocal to tweeter?

Tractrix is interesting but needs space around it so at low frequencies takes up much room and beams if you take it too high. If you use tractrix cross sectional expansion with fixed conical sides, the vertical expansion can beam considerably.

Hyp/Ex might reduce this to find a compromise even though with this sensitivity you could just waveguide it. This would be a big build but it could be made to tolerate being closer to the walls. For a simpler build you could use it as a direct radiator, and maybe it would work well in an upper bass horn where folds are tolerated.
 
a scaled University Classic might be pretty good - mine, built by Triticum Audio is a bit shy of holding a 12" so runs a 10" Eminence - an additional inch or so of depth would have worked for a 12.

https://scontent-ort2-1.xx.fbcdn.ne...=4ef278256a7ad96a35875b62c447a38f&oe=5A71C719

https://scontent-ort2-1.xx.fbcdn.ne...=b1687a6794e1eab0512f054591a320b0&oe=5A64C2CE

I've had 12pe32 in Karlson's distributed slit vent K12 - maybe a bit overdamped with a solid state pro amplifier compared to the Kappa12a type. Those narrow slits develop a lot of noise and harmonics with sine wave in the area of tuning - not noticed normally with music.

http://i.imgur.com/EQcGApb.gif

out of curiosity, my next horn will be a ~0.83 scale Klipsch Belle for 12pe32.
 
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Is this the Vox? What is the lower horn? Also, why do you want to use it as described above because usually the design parameters guide the horn type, and here this isn't clear.

If you want to do a front horn at these frequencies it could be challenging if you can't make it big. You already have plenty of sensitivity so maybe you could compromise there. It may be a difficult choice to fold, but it would help in making use of room corners if you choose a horn that can be used that way.
 

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Trying to process this information, I notice a few things. It is said that it sounds resonant, I don't know why but I think it is small for the frequencies and is made for half-space loading so maybe you could improve on that..

It is ported, which is interesting. Have you played with porting in hornresp.exe? Group delay can be manipulated among other things.

It is said to be solid. Romy will agree, as I do that the rear chamber and throat (at least) should be solid.
 
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One rule of thumb would suggest you should cross that at or just below 300Hz. On the other hand the spike might be less audible because it is at such a low frequency. Will it actually be in 2pi loading? I suspect between that, and the box parameters you might have some control over it.
 
(how does one select TRA in hornresp?) - likewise, I think my 0.83 scale Belle could be vented to extend its low end with 12pe32. I don't know if the low end would extend well with a high source Z amplifier (?) - there may not be quite enough space in this scaled version to equal the vented sim (? - it should be around 33L back chamber at 0.83X)

I'd like to hear how your vented rear chamber horn turns out.

https://i.imgur.com/4txmanm.jpg
 
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100Hz to 500Hz 9 litre sealed box, no horn.

Hiya Arcgotic,

The attached shows a sealed box loading with 9 litres and a Q of 0.62.
Staying within Xmax and 250 watts AES the driver will give superb results... Over 113dB at 100 Hz!
With DSP to Eq the response and crossover to your other drivers you will have a very accurate and natural upper bass / low midrange without any horn resonance or port / transmission line distortion... Accurate time domain performance is vital.

Good luck and all the best
Derek.
 

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