Jordan JX92S enclosure design

AudioGeek · 2004-01-28 4:57 pm

I am looking to build something with the JX92S. Sealed or BR. I do not have any design software so am looking at volumes, port lengths etc that are known to work.

Any help?

Thanks!

Timn8ter · 2004-01-28 5:03 pm

Have you looked at the published designs on the EJ Jordan website?

AudioGeek · 2004-01-28 5:12 pm

yep

yeah... but im looking more for not specific enclosure designs, but recommended volume for sealed and BR and port dimensions for BR.

I can always throw together a baffle step filter... so thats not a problem.

Guess i am looking for a smaller enclosure that has reasonable bass response but has very good transient response.

So for sealed... qtc of 0.5

leadbelly · 2004-01-28 5:34 pm

Re: yep

AudioGeek said:
yeah... but im looking more for not specific enclosure designs, but recommended volume for sealed and BR and port dimensions for BR.

I can always throw together a baffle step filter... so thats not a problem.

You've lost me. If you are willing to design/build a BSC circuit yourself, then if you look at the manufacturer's designs for box volume and port volume, you now have all the information to build it whatever shape you want. Or did I miss something?

Timn8ter · 2004-01-28 5:38 pm

Here's a link about Jim Griffin's award winning design .

AudioGeek · 2004-01-28 7:11 pm

location of port?

do you know if the location of the port in that 0.25 cu foot design is on the back or front?

Thanks@!

Timn8ter · 2004-01-28 8:53 pm

Looks like the port is in the back.

BrianGT · 2004-01-28 10:32 pm

I built a pair of Jordan JX92S mini-monitors based on Jim Griffin's design, and I love them. Here is a collage of picture from my gallery.

--
Brian

BrianGT · 2004-01-28 10:35 pm

I didn't show the port on the back, but it uses the port shown below from parts express. The port length is equal to the exact length of the port without the sliding piece, and it doesn't need to be trimmed or anything.

--
Brian

AudioGeek · 2004-01-29 3:04 pm

Thanks

Thank you for all the replies.

Very usefull stuff.

Is it my understanding that these drivers can only be got at creative sound from canada? (in US).

Also, is an internal MDF enclosure with an external layer of pine or oak a good idea?

BrianGT · 2004-01-29 3:21 pm

Re: Thanks

AudioGeek said:
Thank you for all the replies.

Very usefull stuff.

Is it my understanding that these drivers can only be got at creative sound from canada? (in US).

Also, is an internal MDF enclosure with an external layer of pine or oak a good idea?

For my Seas Thor TL speakers, I did 3/4" mdf covered with 3/4" solid oak on the front, back and top, and 3/4" oak plywood on the sides.

And to my knowledge, CSS is the only US distributor of the JX92s. They are located in Canada, but ship out of Washington state for the US shipments.

--
Brian

moving_electron · 2004-01-29 5:48 pm

Brian,

With the port on the back in this design, do you find that the monitors need to be fairly far out from the wall? Or are you able to use them within a few inches of the wall as the photo suggests?

net-david · 2004-02-04 8:03 pm

I decided to take the plunge and ordered the JX92S's from CSS today. Since I have no woodworking skills, I cheesed out and ordered the #302-704 pre-finished cabinets from partsexpress.com. I ordered the ports that BrianGT suggested.

Would it hurt to place the port on the front baffle?

I still need to get the coils, resistors, binding posts and hookup wire. What power rating does the series resistor need to be? For the inductor I was thinking of the air core Solen or maybe one of the foil coils. I'm feeling esoteric

Thanks,
David

BrianGT · 2004-02-04 8:22 pm

moving_electron said:
With the port on the back in this design, do you find that the monitors need to be fairly far out from the wall? Or are you able to use them within a few inches of the wall as the photo suggests?

It depends on the room. In large rooms, they will sound good removed from the wall with the BSC on them. In small rooms, close to the wall, it is best to not use them with BSC.

net-david said:
I decided to take the plunge and ordered the JX92S's from CSS today. Since I have no woodworking skills, I cheesed out and ordered the #302-704 pre-finished cabinets from partsexpress.com. I ordered the ports that BrianGT suggested.

Would it hurt to place the port on the front baffle?

I still need to get the coils, resistors, binding posts and hookup wire. What power rating does the series resistor need to be? For the inductor I was thinking of the air core Solen or maybe one of the foil coils. I'm feeling esoteric

The port can go on the front if you desire. It would be best for placing the speakers closer to a rear wall. As for the BSC circuit, Jim recommended a 1.5mH inductor, and a 4 ohm resistor in parallel. I recommend getting a Mills resistor for the 4 ohm resistor. For the inductor, I ordered an Erse 1.5mH (parts express) 266-900. I found serveral designs that used these, so I figured it would be fine. It is working fine, since it is only used below 1khz. I considered going with an air coil of copper foil inductor, but i wanted something that would easily fit in the cabinet and have a low DCR. Getting a low DCR 1.5mH air core/foil inductor, makes it quite large, probably 3"x2" for a 12ga with still a higher dcr.

--
Brian

sreten · 2004-02-04 8:53 pm

A 0.5 way with an extra driver is one way of getting more
bass juice and implementing BSC at the same time.

Anyway here are some alignments for a single driver :

sreten.

sreten · 2004-02-04 9:19 pm

with a 0.25 cuft box reflexing is barely worth the trouble :

sreten.

tpenguin · 2004-02-04 10:05 pm

BrianGT said:
It depends on the room. In large rooms, they will sound good removed from the wall with the BSC on them. In small rooms, close to the wall, it is best to not use them with BSC.

The port can go on the front if you desire. It would be best for placing the speakers closer to a rear wall. As for the BSC circuit, Jim recommended a 1.5mH inductor, and a 4 ohm resistor in parallel. I recommend getting a Mills resistor for the 4 ohm resistor. For the inductor, I ordered an Erse 1.5mH (parts express) 266-900. I found serveral designs that used these, so I figured it would be fine.

With the speakers near the wall, in an average room, I think the 4-ohm resistor provides too much compensation, so if you want your speakers to be near a wall, I would try a 2-3Ohm resistor in parallel with the inductor. Of course, this is a matter of personal taste, and either way, speaker placement will probably be the more important factor.

net-david · 2004-02-04 10:23 pm

BrianGT said:
For the inductor, I ordered an Erse 1.5mH (parts express) 266-900.
--
Brian

Doh! partSEXpress is out of stock of these. And, they don't specify the DCR.

Madisound's two iron core 1.5mH inductors with 16ga wire both have a DCR of .14. The Alpha-Core 1.5mh 12ga has DCR of .16.

I don't think the volume displaced by the coil will hurt my application too much, I am already a little over on enclosure size at .3ft3. I guestimated the Alpha-Core's volume at 15in3.

--David

net-david · 2004-02-04 11:59 pm

I got home to my handy printed partsexpress catalog and found the the Erse Super Q 1.5mh inductor has a DCR of .126. I guess I'll wait on them to come back in stock.

I could build the speakers without any BSC and then experiment with it externally.

--David

Colin · 2004-02-05 10:50 am

Would be an advantage keeing the x/over outside the box - less vibration and you can fit the components to a larger board to keep them farther apart.

Colin

Jordan JX92S enclosure design

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