C-40 LF horn cutoff Hz

[toque-eh!]

does anyone know what the low frequency cutoff is for the C-40 Harkness cabinet? would the driver loaded make much difference in that respect? mine are loaded with 150-4c's if that helps.

thanks in advance for any replies.

[Charley Rummel]

The C40, as with the C34 and the C43, has a low end of around 50 Hz, and can reproduce as low as the mid 30's at around minus 10 db. Placement in their environment also has an increasingly significant impact on performance as we get into the lower frequencies.

Regards,
Charley

[Charley Rummel]

(Couldn't finish what I had to say last time)

As for my experiences with these types of enclosures, the 150-4C is a great match; most of them went into horns anyway.

Also, though I don't know what your particular application involves, a mutual coupling effect of the horns can occur if your C40's are within a distance of each other proportional to the wavelengths of a horn with a total mouth area equal to both horns combined. The virtual low end is definitely lower, around 40 Hz (I don't have the data within arms reach at the moment - anyone out there care to look this up?) and as before, placement in the environment will have it's influences.

An extreme example I can compare to is being at a rock concert where the PA main low ends are clusters of "scoops" (4530, 4520, etc.); the sum of the parts gets loud and mighty low.

Regards,
Charley

[Zilch]

See pages 120-121 of the JBL Audio Engineering for Sound Reinforcement manual for an interesting exposition of mutual coupling in LF drivers, the science of "moving" audiences with bass....

[toque-eh!]

thanks for the reply charley. i am definitely hearing sub 50 output from my system, but it must be attenuated, as you say. 50 seems like a believable cutoff though, as far as the horn loaded response goes. maybe the sub 50 output is coming off the driver as directly radiated energy?