Jordan JX92 bookshelf TL

[BrianGT]

Originally posted by tpenguin
If you want bass lower than ~60Hz, I'd recommend you consider a different driver.

That is exactly what I decided after thinking about it for a while.

I also had BSC on my speakers 4 ohm resistor in parallel with a 1.5mH inductor, so they can get boomy if you put them too close to the wall, or in too small of a room. If I bypass the BSC, they sound much better in a small room, but thin in a larger room.

The design is based on Jim Griffin's speakers that I heard over a year ago at the DIYATL2002 event.

--
Brian

[Rafal]

Thanks for all your suggestions.

Brian,

What driver did you finally decide on?

Backing up a bit...

What I am ultimately trying to do is improve upon my current speakers which are Tannoy System 800 Active - professional monitors. The rason I am leaning towards asingle driver is to avoid a passive crossover. Basically what I want to improve is percieved realism of the performance. I have heard some nice Linn active setups and that would be ultimate but the bank sys NO.

Can you suggest an approach, hopefully a single/wide range, that would present a major improvement over my existing setup (and not cost me an arm and a leg)?


Cheers,

Rafal

[tpenguin]

Originally posted by BrianGT




That is exactly what I decided after thinking about it for a while.

I also had BSC on my speakers 4 ohm resistor in parallel with a 1.5mH inductor, so they can get boomy if you put them too close to the wall, or in too small of a room. If I bypass the BSC, they sound much better in a small room, but thin in a larger room.

The design is based on Jim Griffin's speakers that I heard over a year ago at the DIYATL2002 event.

--
Brian

Maybe for the best overall sound you should decrease the BSC by about 2dB?

[Colin]

Another option might be the Jordan VTL, on the Jordan website. It isn't a bookshelf design but the commercial version, the Konus Essence, gets very good reviews and is reported to extend the driver to around 50Hz. I believe there are a few people on this and the fullrange forum who have built this design.

Colin

Jordan VTL transmission line

Konus Essence

[IanHarvey]

I'm currently building some standmount speakers using JX92S's, which I'll post details & measurements of when I've finished fiddling. They're not exactly "bookshelf", at about 15 litres, but roughly the same size as the speakers in your pic. I'm planning on a bass reflex, not TL design, and I'm aiming for a smooth rolloff and good transient response, rather than a boomy highly-tuned one.

A number of reports suggest the driver needs quite a bit of break-in to achieve "full" bass response. This might have some truth to it - out of the box the free-air resonance was about 55Hz, but after an hour of playing LF sweep tones through it, it had dropped by a few Hz.

More later...

Cheers
IH

[Rafal]

Thank you all for your suggestions.
I have considered making the floor standing VTL with Jordan 92's. I even considered pairing it up with a subwoofer. I may still go down that path, but there is something to be said for a beautifully executed bookshelf (like a B&W nautilus 805 Signature).

Ian,

I would be very interested to sread more about your project. can you e-mail me once you have it done?

[Nardis]

I built 7 litre minimonitors using Jim Griifins design, but using an 2x12mm MDF + 2mm lead sandwich. I put the port on the front and use them without BSC against a brick wall. I also exchanged the foam for a Deflex panel on the rear wall and a ring on the rear of thje driver. I thought this gave more sense of air around the instruments.
The mid is superb but they need a subwoofer. I also found the top a bit harsh especially on orchestral strings. and am in the process of adding Fountek JP3 ribbons, which make a big difference in my first lash-up. I need to make new front baffles now.
I'm crossing at 6k with a first order, but am thinking of going up to 7.5k with a 3rd order, following the xover at
http://www.d-s-t.com.au/Ventura/RibbonTweeter.htm