GM's JX92s with tweeter, would that be good?

[_henry_]

hi,

i know a lot of u guys been building GM's design and getting good results.

2 weeks ago i bought the jordans and RT2 planar tweeter from Hi-Vi right now i'm planning to build GM's ML-TL with the rt2.
a friend who is an experienced DIY-er suggest that it will sound good with series x-over with 1,5 mH and prob 1,0 to 2,2 mF caps.

what do u think?

[THOR]

I tried useing this combo , as I had the tweets left from an earlier sys.
My impression of the tweet is its pretty smooth. i tried it with various caps@ various freqs from 5K to 15 K. never got a good match. the dispersion is too different to match with a Jordan . It ALWAYS sounded like a "split" speaker,u loose the coherency of a single point source,the highs are spread vertically as a source over 4" or so and not from a point . If you try to roll off the top of the jordan it SUCKS the life right out of it. i did this as an expierament as other people were sugesting such . its a bad go IMHO. have you listened much to the jordan without tweet? do u really think it needs help? I dont. Warning : it takes a LOOOOOOONG time for it to break in . I sugest you pack pillows tightly around it to damp it, and play it at 90 db or so for about 300 hours using a warble or swept sine from 80 Hz to 20 k otherwise you will prob not like it a lot for some time. make sure the pillows dont hit the alum cone.
after breakin this is one sweet speaker all by itself, and needs nothing.
there was a project about the jordan with an Arum cantus tweet that made a splash on this forum and was supposed to be IT!!!!!, and suddenly dissapeared, never heard of again . prob because of the above !

[planet10]

I don't think the psudeo-ribbons are of high enuff quality to keep up with the Jordan.

Have an upcoming project coming with JX92 & the smallest AC tweeter (and a pr of ApexJr Super 8s on the bottom). This could well end up being tri-amped. Will keep you aprised.

dave

[Jim Griffin]

Al Wooley gave us a preview of this speaker design (Jordan JX92S and Aurum Cantus G2si two-way) earlier this spring in his posting:

Few new Jordan designs with a tweeter.

The final assembly/design was completed this summer and I’m very pleased with the results. These two drivers blend very well. The G2si adds a sparkle in the upper octaves that is missing in the Jordan JX92S if it is used full range.

This design corrects for on-axis response roughness exhibited in the JX92S operation above 7000 Hz (see http://www.ejjordan.co.uk/drive_frameset2.htm ). Also above 3000 Hz the 30 degrees off-axis response of the JX92S starts to drop (shows beaming) and is especially rough as frequency continues to increase. Hence, a 3000 Hz crossover point was selected as ideal so that wide horizontal dispersion could be preserved throughout the response range. Hence, this design blends the coherency of the JX92S with the quickness of the small G2si ribbon. The speaker is voiced to be natural sounding without being overly bright across the upper mid and treble regions. Perhaps the only down side to this design is that with 3 dB of baffle step compensation, the overall sensitivity of the speaker is 84 dB SPL 1w/1m.

Finally, the enclosure is a 0.33 cu. ft. ported box with a 1.375” diameter port tube. Bob Reimer of Creative Sound Solutions (www.creativesound.ca) will offer drivers, parts, cabinets, and detailed plans for this design.

Jim

[Colin]

The best tweeter for the JX92 (apart from none) is probably the JX53 - same materials, same directivity pattern. Neither of these units is designed to be listened to on-axis, the axis should cross well in front of the listener.

The 53 would be a good match crossing over first order around 500Hz - you could probably use the x/over on the Jordan site, though the 92 may need padding down a little as it is slightly more sensitive than the 53.

Colin

[_henry_]

thank's everybody for your insights.

i haven't build the cabs yet, but tomorrow i will start to build it.
the reason why i want to add the tweeter because i want the extended response higher, and RT2 currently available, and the g2si is currently out of my budget.

right now i think i will build it with a single jordan first, then i will decide later if i want to add the T or not.

Are there any T besides G2si that prob can match the jordans?

and any of u used the RT2, what would be a good match for them?

[planet10]

Originally posted by Colin
The best tweeter for the JX92 (apart from none) is probably the JX53

This is what my German friend decided after trying a number of tweeters with his JX150, later he decided that he liked it better without the tweeter at all -- i'm still going to stubbornly go ahead and try with the G2si.

The 53 would be a good match crossing over first order around 500Hz

JX150/JX53 above was XOed at about 3-4k (series)... mating 2 essentially FR speakers gives a lot of vrsatility in terms od XO placement.

dave

[_henry_]

Dave, i know that u have many experience with fostex FR, how about their FT96h Horn Super T with alnico?

will it be up to the jx92s standards?





henry

[planet10]

Originally posted by _henry_
how about their FT96h Horn Super T with alnico?

will it be up to the jx92s standards?

I haven't had any experience with the big-buck Fostexes, but i haven't met one i didn't like yet. It is undoubtedly a very good tweeter, but there are more ingredients to the equation than just good.

If used as a super-tweeter at the top end of a FR, i've found that the narrower dispersion of a horn better mates up with the dispersion at the top end of the FR thou.

dave

[Nardis]

Ý use the Fountek JP3 wýth the JX92S ýn a nodded versýon of Jim Grýffins mýnmonýtor desýgn . Ý am pleased although it is not as good as the GS2 Ý have heard. Ýt is a lot cheaper however.

Xover ýs 6.3k fýrst order wýth zobels on both and the rýbbon padded.

The rýbbon ýs at the lower lýmýt of ýts freq range and needs care when used fýrst order. Ý found the JX92 too harsh on strýngs used by ýtself. The ribbon opens ýt out.
oard - excuse the strange spellıngs
Ý intend to try the GM MLTL wýth both drývers.

Am in Turkey on holıday usıng a Turkısh keyboard so excuse the strange spellıngs!