Double 136a's with single 2118?

[subwoof]

Well I will step away from this argument...seems that all sides have a part of the answer while no one has it all...and I do not profess to because this is NOT a linear equation and the variables are not exactly defined. Different cabinets, loading, spacing, placement, etc ALL go into play with LF cone coupling.

There seems to be a lot of confusion over doubling - in DB terms doubling the voltage is 6db, power 3db, This is indisputable.

BUT a smattering of amplifier scenarios and cabinet couplings have been presented on this thread so it is not comparing apples to oranges, litres to quarts or kumquats to koala's

Anyways, my point is that the paper cone on the 2118 is a thin, rip-prone mistake from JBL. In the multitudes of cones that have passed thru the JBL service center I helped set up in 1993, COUNTLESS 2118. 2119 and their variants have come into the shop with paper cone damage even from systems that were power controlled, within "spec" and generally well taken care of. They are just too SMALL for any decent application.

If you want to use a cone mid above a PAIR of 136A'a that I strongly suggest either the 2202 ( AKA the 4355 monitor ) or the 2012H high power 10"

The 2012's frame width is only 1/8 inch wider that the extended lip on the 2118 and you have a REAL high power cone / coil and a large magnet.

Sell the 2118's and move up.

sub

[Zilch]

It's covered in the Eargle sound reinforcement manual in the subwoofer section. Mutual coupling gives you an extra 3 dB. With each doubling of drivers, the frequency at which mutual coupling occurs also moves lower, so at some point (8 drivers, as I recall,) you're done with the free lunch....

[rs237]

Zilch hello, the free lunch is not dependent on the number of Driver. The free lunch will end when the distance between the membrane centers larger than 1/4 wavelength. By two tightly side by side mounted 15 "drivers out of the Mutual coupling already at about 200Hz. Look here
http://www.audioheritage.org/vbullet...ght=TAD&page=3
http://audioheritage.org/vbulletin/s...ic+coupling%22


regards
juergen