THE NEW CELESTION CF18VJD TESTED TO THE MAX

2.5kW into each driver then?

kevinmcdonough wrote: hey Can we have more details about this driver, is it a solid hardcore horn/small rear chamber driver like a PD1850/V18-1000, a more reflex orentated driver or an inbetweenie thats suitable for ported horns and larger chamber scoops etc?

Everything you need to know is in the specs & T/S really..

http://celestion.com/product/5/cf18vjd/

Suprisingly, the accurate Xmax is mentioned above, so in PD/Fane terms call it, 12mm.

Has strange Vas like 1851/Turbomax so HR & modelling software will not model it properly.

Fs/Qes ratio is fairly "horny", but not tight like 1850, so probably won't appreciate tight throat/expansion, or small chamber scoops. Qes of > 0.30 also suggests this.

Has good BL, so coupled with lowish Vas, & EBP > 100, suggests plenty of control, even at 800W & above in medium chamber scoop.

Overall depth is 233mm, "guestimate" 223mm depth from inside front rim to rear of magnet. So will not fit in most small chamber scoops, unless double front baffle. Usually a good idea to have at least 25mm betwixt driver magnet & rear baffle.

E.g, 1850 is approx 175mm deep (not inc rim), ASS RX18 is chamber is approx 190mm deep, Superscooper is 210mm deep.

So expect this to like all the cabs a Turbomax 1200 likes, and why the Earthshaker scoop design is as it is.


Edited by levyte357 - 12 March 2012 at 4:32pm

toastyghost wrote: Lev, can you get one and do you fancy a trip to Manchester to try it in something new that may be interesting? In typical roots fashion I can't fully divulge the details...

Sure LIGWA won't lend them out.

He may allow you to bring cab to his place and try it in there.

levyte357 wrote: From what I understand, the drivers were 8 ohm. The amplifier is rated 5kwpc @ 4 ohms.

I thought the FFA 10k was 5kw rms per channel at 2 ohms? or is this a new amp?

Just looking at the Celestion CF18VJD would explain why the amplifiers need to be bridged in order to achieve a reasonable amount of SPL.

What is most intresting about this driver is the VD hasn't changed in the past 30 years when you compare the CF 18VJD to older top of the line 18-nch drivers from Celestion despite offering more xmax.

Celestion was very conservative on their xmax decades ago and, now may have decided to be more upfront based on competition.

I do recall Celestion 18-inch drivers had a tendency to distort when driven hard which, may be a good or bad thing pending on the cabinet you put them in.

Best Regards,

levyte357 wrote: Elliot Thompson wrote: Just looking at the Celestion CF18VJD would explain why the amplifiers need to be bridged in order to achieve a reasonable amount of SPL. Personally don't believe Manufacturers sensitivity figures, so have a dynamic spreadsheet which calculates driver no from few T/S parms, then I re-order  sheet to according to most Efficient to least.

Once the no.% states a figure, there is no getting around it. It is one of the oldest figures listed in the TS Parameters yet many still pay no attention to it.

 

 

 

Best Regards,