CoEntrant coaxial technology

[454Casull]

http://www.renkus-heinz.com/technolo...ch_pat_co.html

It's funny how much you can manipulate sound waves, though I do wonder how this sounds...

[Mudge]

It seems remarkably similar to SPL's Unity horns, although I'm assuming they use an hyperbolic/tractrix horn with a single throat and multiple drivers firing into the throat chamber, rather than multiple throats along the body of the horn.

[BillFitzmaurice]

It seems remarkably similar to SPL's Unity horns

And the Unity horns were remarkably similar to the EV Manifold Horn systems; this is not a new concept at all. If you want to see another example of this concept at work look at the mid drivers in JBL or EAW pro-touring line arrays, both of which use two to four drivers feeding a single horn.

On the upside you can get a lot of power handling with this arrangement. On the downside for every doubling of drivers you only pick up an additional 3dB of voltage sensitivity, all of it from the increased power handling factor. You don't get any additional radiating sensitivity, as that is a product of the horn mouth area, which remains the same irrespective of the number of drivers in the throat. Therefore putting the same drivers each into their own horns of the same size will give an additional 3dB output per doubling of drivers over a manifold loading of a single horn.

There is another downside to this arrangement, as there comes a point where too much input power causes the throat to suffer from an acoustic overload, with serious distortion resulting. EV had to add spacers between the drivers and the throat to control this, with a loss of sensitivity being a consequence.

Where this arrangement is most useful is with high Fs/low Qts/ low Xmax midrange drivers where the total displacement at max Pe won't overload the throat; with long throw bass drivers that can happen with the air displacement of a single driver, making the addition of more drivers useless.

www.billfitzmaurice.com

[Mudge]

Originally posted by BillFitzmaurice

There is another downside to this arrangement, as there comes a point where too much input power causes the throat to suffer from an acoustic overload, with serious distortion resulting. EV had to add spacers between the drivers and the throat to control this, with a loss of sensitivity being a consequence.

Isn't that an area where the aperture summation designs score better, as obviously each driver has it's own throat, rather than multiple drivers feeding a single throat chamber.

I agree with you about the use of this design with classic PA midrange drivers, the benefits are quite obvious.

[BillFitzmaurice]

Isn't that an area where the aperture summation designs score better, as obviously each driver has it's own throat, rather than multiple drivers feeding a single throat chamber

Absolutely, though even then the summed throats could overload where they combine if the acoustic impedance of the horn at the summation point is high enough. With midrange drivers and the limited excursions involved neither throat arrangement is likely to be problematic, but if you take it as low as EV does with the MH4020, to 100Hz, then the potential for serious power compression and throat distortion is there even with the high Bl EV DLX10 drivers used. I don't see manifold loading as being fool-proof much below 500 Hz.

[pinkmouse]

Having used Renkus systems a lot I have to say they sound good, and the dispersion is well controlled enough that you don't generally need to do much room correction. As to the throat compression issues that Bill mentions, that is purely down to specifying the correct spec. for the gig, (most boxes sound unpleasant if pushed too far), and this is generally due to people being cheapskates and not getting enough kit in to do the job properly...

[BAM]

My high school had Renkus-Heinz speakers. They sounded very good, as I remember. Better than I ever expected PA speakers to sound.

[phase_accurate]

BTW: One of the senior engineers of RH is a member of this forum. Maybe he would answer detailed questions.

Regards

Charles