| cheesehead |
So, I've built the GM/Abpea "first draft" Jordan JX92s MLTL's. Described right here. They're beautiful. Right now I'm listening to Michael McDonald's "Motown" - I still jump at some of the percussion, it's that good.
But I want to add baffle step compensation, 'cuz Michael's a little weak. OK, I can do inductors & follow formulas, and get about a 2 mH inductor || with a resistor I'll play around with to match the room. But I noticed that Martin King & Bob Brines have included a zobel with their Fostex full-range designs... on the other hand, from what I can find Jim Griffin's Jordan design does not.
Should I include a zobel for the Jordan?
mk |
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| cheesehead |
| oh, and, doh, I'm driving it with your average commercial 5.1 solid state receiver... |
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| GM |
Interesting! You are the first person I am aware of that has felt it needed some BSC. Anyway, yes, I would try a Zobel. Just using the published specs/plot, I get 5.625 ohms/5.053 uF to reactance annul Re (assumes 4.5 ohms). Really, with a Zobel, you may not feel the need for any BSC.
Anyway, please let us know the results and what you wound up using.
GM |
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| tcpip |
| Newbie question: the Jordan Website has recommendations of RL pairs to use with the JX92S in their standard boxes. These, I thought, were to strengthen the bottom end. Are these for BSC purposes? |
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| navin |
| hey TCPIP what box did you build for your JX92? |
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| Timn8ter |
| quote: | | I'm driving it with your average commercial 5.1 solid state receiver. |
Could we be seeing the difference between voltage and current source and/or a damping factor contribution? |
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| GM |
| quote: | Originally posted by tcpip
Newbie question: the Jordan Website has recommendations of RL pairs to use with the JX92S in their standard boxes. These, I thought, were to strengthen the bottom end. Are these for BSC purposes? |
Yes, though different values may be required for your app.
| quote: | Originally posted by Timn8ter
Could we be seeing the difference between voltage and current source and/or a damping factor contribution? |
AFAIK, all the other folks who have built the various ML-TLs are using SS, and while it's possible the receiver is 'laying down' if it's not rated for < a nominal 8 ohm load, I doubt it. Regardless, a Zobel and/or series resistor should remedy the problem.
GM |
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| tcpip |
| quote: | Originally posted by navin
hey TCPIP what box did you build for your JX92? |
Ordinary ported box, a little less than 18" tall on the outside. This is from the Jordan Website. I haven't tried GM's MLTL yet, though he had posted some of those details on this Website in response to one of my questions. GM and 7V had both been very helpful and encouraging. But I've since got caught up in another project. |
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| tcpip |
| quote: | Originally posted by GM
Yes, though different values may be required for your app.
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Okay, thanks. Will try it out and listen... haven't fitted any BSC on my ported box, and the sound does sound thin half the time. |
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| cheesehead |
| quote: | Originally posted by GM
Interesting! You are the first person I am aware of that has felt it needed some BSC. Anyway, yes, I would try a Zobel. Just using the published specs/plot, I get 5.625 ohms/5.053 uF to reactance annul Re (assumes 4.5 ohms). Really, with a Zobel, you may not feel the need for any BSC.
Anyway, please let us know the results and what you wound up using.
GM |
Preliminary report - I used this Zobel & a parallel 1.2 mH/2.5 ohm resistor for BSC. Yuck! Sounds muddy, boomy, like I put the speakers inside of a cardboard box. High end treble gone? I've gotta get a mic & preamp & start measuring frequency.
FWIW, I also included a driver brace as recommended in the original thread.
Of course, I put the zobel & BSC inside of the box, since I was "finishing" it :smash: . (They now they look great, just sound awful) This weekend I'm going to pull it out, re-stuff, and try the darned thing again, but with just zobel, just BSC (and do them external), just driver brace... the way I should have. |
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| Timn8ter |
| quote: | | I put the zobel & BSC inside of the box, since I was "finishing" it |
Been there, done that. Makes one start to consider external crossovers as part of the design. :xeye: |
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| navin |
| quote: | Originally posted by tcpip
Ordinary ported box....GM and 7V had both been very helpful and encouraging. But I've since got caught up in another project. |
BTW since you are the only person i know in India that has Jordan drivers of recent vintage (I knew of someone with the original jordan 50mm modules) how would you compare them with say a B&W 303, Epos ELS 3, Castle Richmond, Quad 11L or other speakers in that price range ($300-500/pair). The 92s cost about $270 per pair. add another $100 for cabinetry and we are looking at $350-400 per pair. I am looking at 3 pairs of a 6.1 system driven by a Marantz SR7000. The subs would be 4 x 12" (have not decided on the configuration yet) powered by a Carver 1.0t.
The sole reason for using the Carver is that it runs cool even in "virtually encolsed" conditions.
my intention is to use the system for HT and some music. the boxes i hope will look like something this http://www.musicalapproach.co.uk/news/KEF_KHT_9000.jpg
one other alternate i am considering (mostly due to WAF and my limited wood working skills) is speaker like the triangle titus, snell type Q, ALON/NOLA LITTLE RASCAL III, Monitor Audio 2.5, etc. |
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| tcpip |
| quote: | Originally posted by navin
BTW since you are the only person i know in India that has Jordan drivers of recent vintage (I knew of someone with the original jordan 50mm modules) how would you compare them with say a B&W 303, Epos ELS 3, Castle Richmond, Quad 11L or other speakers in that price range ($300-500/pair). |
Sorry Navin, no idea how those others sound. But I know some people who have heard very expensive finished speakers (e.g. Avalons, Dunlavys) and who then heard my Jordan drivers and said they sounded excellent. This is a very roundabout testimonial, but this is the best I have.| quote: | | The 92s cost about $270 per pair. add another $100 for cabinetry and we are looking at $350-400 per pair. |
I bought them from the UK, and EJ Jordan sold them for UKP 77 each, I think. That makes it more like USD 200 per pair, I'd have thought. And my cabinetry costs for small ported cabinets was about Rs.5000 per pair, which tallies with your figure. However, if you will add a sub, you might as well make even smaller cabinets (e.g. the sealed cubes on the Jordan site), and cut costs a bit further, specially since you are talking of making half a dozen.
I don't know whether it's very important to you to really compare the Jordan against any specific benchmark. If not, then just try one pair and see for yourself --- they are so good that they will not disappoint you by any absolute standards. |
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| navin |
thanks for everything TCP. madisound i think has them listed for $135 each. Also I hope they offer a dicsount when someone is nuts enough to get 6.
my other alternate was the FX120 from Fostex. i hear is sounds great and it's big brother FX200 is part of the holy grail fullrange system on the fullrange driver site. but it has a 70Hz limit, a Xmax of only 2mm and is limited to about 10W rms. the difficult part of many fostex drivers is that few affordable LF units match their sound. otherwise drivers like the FF85K and the FX120 would be nice to try in a 1.5 way. |
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| cheesehead |
Just finished pulling my my BSC/zobel out of my GM-designed Jordan MLTL's.
So:
With driver brace, zobel, BSC removed - I've got my nice speakers back!
With the driver brace - no difference with it tightened/off that I could tell.
With the BSC - :) a little better on the lows. Drums & bass sound like drums & bass. Might be a little boomy, but I'll wait until I get my mic & preamp and measure the frequency response.
With the zobel - the highs are gone, baby, gone :bawling: .
So it's now running with the BSC (1.2 mH 2.4 ohm parallel). Michael McDonald sounds nice and full, which makes the spouse happy... which makes me happy ;) |
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| navin |
cheese,
what music do you listen to?
do you have a pic of the nice speaker?
Thanks. |
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| cheesehead |
| quote: | Originally posted by navin
what music do you listen to?
do you have a pic of the nice speaker? |
Navin,
pics below:
As you can tell, these are now the fronts for HT. We played the Star Wars DVD's the last couple of days. Very good.
The speakers are made of oak-veneered MDF, cut 45 deg on edge for the joints. The top was oak veneer glued on with contact cement; the edges on the sides facing the front have iron-on veneer. No joints visible. Finish is stain + several coats of polyurethane; I used 000 steel wool after the final coat.
Music... most often played between the spouse and I
Older stuff: Police, Steely Dan, Eagles, Elvis Costello, Elton John... all sounds pretty good.
Female vocals k.d. lang, Indigo Girls, Mary Chapin Carpenter, Alison Krauss (sounds wonderful on the speakers)
a little (alt)-country - Dixie Chicks, Lyle Lovett, Neko Case
My brother-in-law said that Dave Matthews was so-so before BSC, with it I can't get him from in front of the speakers...
Things that sound lousy:
The Beatles One album (sounds harsh?) - can't even play it.
Eric Clapton/Derek & the Dominos/Layla sounds really thin & flat.
Next steps:
1) Get a preamp & mic & learn Speaker Workshop! See what additional tweaks might be necessary.
2) Build a sub - I'm thinking of a Shiva, sealed.
cheesehead |
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| navin |
| quote: | Originally posted by cheesehead
pics below:
Music... Police, Steely Dan, Eagles, Elvis Costello, Elton John...
Things that sound lousy:
The Beatles One album (sounds harsh?) - can't even play it.
Eric Clapton/Derek & the Dominos/Layla sounds really thin & flat....2) Build a sub - I'm thinking of a Shiva, sealed. |
thanks. you mean to say u run these fullrange for HT with no sub at the present? wow! HT usually requires a lot of air esp for the special effects. my intention is to run these from my HT/AVR with the AVR speaker set up set to small (XO at 100hz).
Have you tried heavier music (Black Sabbath, Aerosmith, Who, Stones, AC/DC, etc..). which beatles album sounds flat i have quite a few of them. Do other EC albums sound thin too (I assume this is after BSC)?
thanks again and sorry for being such a pest. |
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| cheesehead |
| quote: | Originally posted by navin
you mean to say u run these fullrange for HT with no sub at the present? |
Yes. And the speakers are set for "large" with the LFE re-directed to them. It's not the full experience, but it's still pretty darned good. I could feel explosions through the floor when my kids were watching the original Star Wars downstairs. | quote: | | Have you tried heavier music (Black Sabbath, Aerosmith, Who, Stones, AC/DC, etc..). which beatles album sounds flat... Do other EC albums sound thin too |
Don't have much of that; what I have is on vinyl and my turntable or receiver/preamp are screwed up. I've got the Beatles One on CD, and it's not flat, it's harsh. (Treble pumped up too high on the remaster?) Elvis Costello sounds fine, but those are rips I did from LP --> CD. |
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| cheesehead |
| quote: | Originally posted by navin
my intention is to run these from my HT/AVR with the AVR speaker set up set to small (XO at 100hz). |
Navin,
Have you thought of running the Jordans sealed? They should give a f3 of ~80 Hz in a 7.5 L volume... I know there are some posts on this on the fullrange forum. |
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| navin |
| quote: | Originally posted by cheesehead
Have you thought of running the Jordans sealed? They should give a f3 of ~80 Hz in a 7.5 L volume... I know there are some posts on this on the fullrange forum. |
Yup I did. but I have a strange way of working. I prefer to look at all options. besides I live in india and they only way we can get drivers here are a reasonable cost if a few of us get together on a purchase. so if i get 5 JX92s and convince a few of my friends to get some drivers (from the same retailer) then we save on shipping costs. since duties and taxes are on CIF it helps. by using the same driver in different systems i get to convince some friends to get 2 or 3 (rear and center) etc... so while i use them in 5 channels, another friend will use them as a PC system and another as center and rear only etc...i hope to collect a lot of say 20 drivers before ordering. so far 5 JX92 and 2 FX120 for me.
thanks for all the help. |
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| tcpip |
| quote: | Originally posted by navin
madisound i think has them listed for $135 each. |
Are you sure? I didn't see any mention of Jordans on the Madisound catalog; I checked a minute ago. The only people who retail Jordan drivers in the NA continent appear to be Creative Sound, but you seem to have got the price right: they are quoting USD 140. |
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| navin |
| quote: | Originally posted by tcpip
Are you sure? I didn't see any mention of Jordans on the Madisound catalog; ..but you seem to have got the price right: they are quoting USD 140. |
u are right. maybe i forgot where i was looking. i had researched the prices some time ago. my budget was for a fullrange under $150 that worked well (95db at 100Hz+, neutral yet lively) in 12 liters or under with no tweeter and only a HT sub for the low end. I ended up with 2 choices - Fostex FX120 and Jordan JX92. Now it seems I might get both. 2 FX120 and 5 JX92. the sad part is that the apt where i intend to house these 2 systems along with one more for which i already have the components is not ready yet. so i will wait a bit before ordering just in case Fostex revises the FX120 or Jordan the JX92. |
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| Colin |
Navin - You could try ordering the JX92s direct from Jordan and see what they would charge for 5 units.
Colin |
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