Cerwin-Vega JE36 replacement drivers

[steve hawkins]

I have 4 second hand JE36 Cerwin-Vega Earthquake bins. They are un-loaded and I was hoping someone could offer some advice regarding replacement drivers. I have a really old pair which have been fitted with Fane Colossus 18XB drivers and 'I think' they sound o.k. I intend to use the cabinets up to 80Hz and down to 35-40Hz. There are so many different drivers available that I don't know what would be most suitable without spending a fortune. The options I have been considering are PD186, Fane 18XB, Eminence Omega 18. Any help or advice would be most appreciated. I would use Cerwin-Vega drivers but they are expensive here in the UK. Many thanks.

Steve Hawkins

[Rademakers]

Do you have T/S-parameters of the original drivers?

Second possibility is to simulate the drivers in Hornresp and see which one comes out best.

Btw, are you going to use them in a stack, or two a side?

Wkr Johan

[Peavey MB1 MB-2]

Beyma 18-G50 , has the biggest SD over 1320!!
match.dk ballister sub says they sound 1dB louder becouse the 18" driver cone area has an SD of 1280!, Beyma 18G50 it's BiGGER! SD, also, has 4.5" voice coil that holds the paper cone,
has great BL! 28.8, gives loud & great freq. response in a sealed enclosure!, verry nice 9mm Xmax

BMSpro.info 18N850 has 13mm of Xmax, great BL over 31!!, but gives a bit less response in a sealed enclosure!
http://www.assistanceaudio.com/02_BMScones.html

PD1850, has all the numbers right, but the voice coil its larger 5" make it a bit slow,

Ciare 18.00SW has great BL, nice Xmax 11.5, a really strengh cone, but gives poor SPL response from 100Hz to 200Hz !
www.usspeaker.com

McCauley 6174, has the cone strengh, the Xmax of 15mm, and the response in a closed box could give a verry nice 50Hz, 60Hz, 70Hz, boost! but the BL maybe its not enough! to handle a front horn & has half the price of the aurasound

the Aura Sound NRT18-8, has the 18mm Xmax, the BL, the Cone strengh, but the price its over $900.us.dls
http://www.madisound.com/cgi-bin/ind....8784&pid=2076

BL its the magnetic strengh, magnet strengh & voice coil, it's needed to move the cone in such hostile enviroment like a verry small closed box in the back and a front folded horn with a small horn lengh,

cone strengh its needed for not breaking under heavy SPL, sound pressure levels, or large Xmax movement

Big Xmax its needed becouse front horns go crazy down the 1/4 wavelengh cuttoff point of the horn even with a verry small closed box in the back making oposite pressure!

speed of sound= 344meters/s = 1Hz, so 100Hz = 3.44mters of real horn lengh / 4 = 25Hz, a 25Hz Hipass filter should be used, if the horn lengh its 3.44meters,, i dont know any horn comercially available that long!

the B36 have verry smaller horn folded lengh,
emacoustics.co.uk ms-115 has 9ft! EAW bh822 has 12ft.!!! most like martin wsx have 6ft o 7ft of horn length, i think cerwin vega older B36 have a really small horn lengh,

so if the horn folded lengh its 2 meters = 172Hz / 4 = 43Hz from that the driver goes crazy Xmax even with the verry small closed box in the back,
= so a verry big Xmax driver should be used, or a Hipass 24dB/oct filter at 43Hz should be used, its required!

thats the purpose of the verry small closed box where the driver fits, to minimize Xmax of the driver, and make the horn beleive its bigger!
but needs a BL near 28, to handle the power compression the air makes to the cone!

the aluminium door in most cerwinvega "aluminium wall" in the verry small closed box where the driver couples with the horn, its to reduce temperature!
so drivers shoundt be used at rated power AES,
for example the Beyma has 75Ow AES = 8 hours of pink noise with 3dB fast peaks each hour!, so it should be used with less watts, if: you live in a hot place, and/or drive for more than 2 hours! if dont want to buy replacements each weekend!

Folded Horns should be used in groups of 8 to go low, deeper in the freq. response, all close together, same electrical phase, floor , or floor and wall, or corner = floor + 2 walls,

Folded Horns sound verry loud from 100Hz to 200Hz, , down from 100Hz its the coupling of 8 boxes,
total box mouth circunference must be equal to cutt off point, so for a 40Hz, should be 8.6meters,

if you can purchase 1 driver of each brand , and test them one in each box, and post the reply would be great!
with test tones and a SPL meter,
the beyma 18G50
or the mccauley 6174 look verry intersting,
also the BMS,
or the presicion devices pd1850, looks so so
or the ciare 18.00SW,


Thanks