2 way MTM using Jordan JX150?

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Hi,
I was hoping someone here had experience with JX150's being run full range, i.e. any problems with cone breakup etc. Maybe planet10 would be able to help here? :)
What I was thinking was using these in MTM configuration (I don't think I can cope with 88-89dB efficiency at the moment :() and running the jordans full range, and accepting its natural roll off at the top end (unfortunately I can only find graphs up to 10kHz) and using a single tweeter to 'fill in' the 'missing bit', technical terms and all that....
Thanks everyone,
Steve
 
The smaller JX125 has been run with a ribbon tweeter in a Townshend design, back in the mid-90s. That got good reviews in The Gramaphone. I believe it crossed over around 5k. I've also seen a Swiss design which had two JX125s with one JX53. It sounded ok but I'm not sure why they did it. (It wasn't a MTM design.)

FWIW, I use a JX125/JX53 system with a mk 2 Nait, rated at around 15 watts, and it gives a good volume in a 19 x 10 foot room. Could do with a little more power on deep bass notes but otherwise fine.

The JX93 is more sensitive - how about 2 of those?

Colin
 
Hi,
Thanks for all your help.

navin:
yes i know, for single drivers. But i would need more sensitivity unfortunately, and i don't really want to double up the hf drivers for fear of any comb effects, as well as aesthetics.

colin:
The JX93 would be a nice idea, but their DC resistance of 4.5ohms scares me a bit. I don't really want to drop too far below 4ohms overall, ill give it a quick model in lspcad though and see what it comes out like, and it's still not as sensitive as the JX150. Im sure there must be some crossover tricks (besides adding series resistors) that allows an increase in overall impedance.

Thanks again,
Steve
 
baggystevo82 said:
Hi,
I was hoping someone here had experience with JX150's being run full range, i.e. any problems with cone breakup etc. Maybe planet10 would be able to help here? :)
What I was thinking was using these in MTM configuration (I don't think I can cope with 88-89dB efficiency at the moment :() and running the jordans full range, and accepting its natural roll off at the top end (unfortunately I can only find graphs up to 10kHz) and using a single tweeter to 'fill in' the 'missing bit', technical terms and all that....
Thanks everyone,
Steve

Well after BSC 88/89dB sensitivity is what you'd get from
an MTM, unless you do baffle step correction at line level.

If you don't do line level BSC then a TMM 2.5 way is IMO
a better option.

I'll also note two jx150's in parallel for sensitivity will be 4 ohm.

http://www.t-linespeakers.org/projects/rune/intro.html

Has a lot of useful information, and is a very good design.

Comparison of the waterfalls shows running the jx150 full range
is not a good idea, and the driver is designed purposefully to be
used with the jx53, and this is the best way of using it.

:) sreten.
 
Cheers Sreten. 4ohms is fine, though im playing around with the idea of using some bandor 150's at the moment which they make with 16ohm nominal impedence. The freq response curve on their site also goes up to 20kHz, would this imply that these could be run full range? Not sure how much of an issue baffle step will be as these speakers will be fairly close to the wall, i assume that helps? Baffle step correction at the line level stage means active xover? Would that work effectively like a little 'bass boost'. How about designing the enclosure volume/res freq to give a theoretical lift with an infinite baffle, to compensate a bit for the use of a finite baffle, would that work/help?
Cheers,
Steve
 
Well, this is what Ive got so far. It looks like it might work OK.
speakers are:
2*Bandor 150-16
Seas 27TFFC

Steve
 

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