My impression of the Planet10 Fonken

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Daze,

If you haven't already done so, check out Sonngsc's two posts on EnABL treating the Jordan JX92S. The first post is a long set of test data with increasing use of EnABL patterns. Post 279 is some ground breaking info on how to treat one so that all resonant modes disappear. Notice the phase information for high frequencies in the first post. I do not see any reason the Fonken box would not sound terrific with the Jordon driver, certainly the Fostex 127 E sounded quite good.

http://www.diyaudio.com/forums/showthread.php?postid=1227789#post1227789
http://www.diyaudio.com/forums/showthread.php?postid=1231568#post1231568

Bud
 
I suspect a Fonken style enclosure might not be the way to go; most of the posts I've seen of DIY or even commercial speaker products have been some form of TL , and there is also the BIB

Just for fun I dumped the Jordan TS numbers into the Onken calculator and WinISD alpha for confirmation. The JX92 would like to have 28" long vents for 44Hz tuning in a 15L box (not including 5L vent volume).
Not looking good at all in a Fonken box, however the Floorstander MkII would work with some minor box adjustments and one long vent. F3 would be around 43Hz, with a vent length of just over 17".

Jeff
 
chrisb said:
My only experience with the JX92 has been the 48" triangulated TL design as posted on the Jordon website. I simply didn't care for the sound of it, and while I'd normally not let one such experience turn me off a particular driver or enclosure design, the price tag associated with the Jordans certainly could.

Admittedly the pair of JX92s in those boxes had suffered from excessive thermal stress and i have the feeling they weren't respresentative...

dave
 
planet10 said:


Admittedly the pair of JX92s in those boxes had suffered from excessive thermal stress and i have the feeling they weren't representative...

dave


perhaps

Originally posted by Vinylkid58

Just for fun I dumped the Jordan TS numbers into the Onken calculator and WinISD alpha for confirmation. The JX92 would like to have 28" long vents for 44Hz tuning in a 15L box (not including 5L vent volume).
Not looking good at all in a Fonken box, however the Floorstander MkII would work with some minor box adjustments and one long vent. F3 would be around 43Hz, with a vent length of just over 17".

I'd be happy to listen to a pair of these - anyone got a pair of drivers to loan us for a few months?
Just kidding, the last thing I need is another pair of speakers I never listen to.

Seriously, the Jordans represent a large investment in drivers, and for anyone considering them for the Floorstanders, it might be worthwhile double checking the math with Dave. I could be wrong, but I'm not sure the basic Onken calculator would apply. A major feature of the Fonken design is the aperiodic affect of the multiple small CSA port slots - if you "simplified" things too much to a single long vent, that control might be lost.
 
chrisb said:

Seriously, the Jordans represent a large investment in drivers, and for anyone considering them for the Floorstanders, it might be worthwhile double checking the math with Dave. I could be wrong, but I'm not sure the basic Onken calculator would apply. A major feature of the Fonken design is the aperiodic affect of the multiple small CSA port slots - if you "simplified" things too much to a single long vent, that control might be lost.


I'm just using the software to predict the response of a given driver, I'm not actually doing the math. That doesn't mean that I'm right though, so anyone can check the numbers if they feel it's necessary. I certainly don't want someone to blow $500 on drivers and build speakers that don't sound right.

Neither WinISD nor the Excel Onken calculator can model the resistance of ports (not that I know of anyway), whether there is one or six. One long vent is definitely not going to behave like six skinny ones, so yes the same ability to overdrive a FE127 in a TL or TQWT (because of less port resistance) could happen to the JX92, even with it's larger power rating.

This is all IMHO of course.🙂

Jeff
 
A Jordan Fonken? Interesting idea. I can't calc. multiple distributed vents, aside from trating them as a single-location lumped parameter, but here's one idea in the classic GR Fonen style with a single vent:

Internal dimensions 20in. CSA 36in^2. Zdriver 5in. Slot vent a la Fonken 1/2in tall x 6in long. Internal top, rear wall and one side wall lined. The vent can be additionally damped via a piece of reticulated foam in its throat if desired. Excursion doesn't look too bad.
 

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maxro said:
No, I went for a Tamiya acrylic for the blocks. I still have to look for a caligraphy pen and nibs(Island Blueprint, perhaps).

I ended up with Micro Scale for the blocks but i'm going to keep looking -- Michaels has a huge array of colours in their housebrand stuff.

You going to do your FR125s?

Island blue has the pens... althou the pen comes in 0.60 or 0.70 (and pricey -- i'll be looking elsewhere for a backup)

dave
 
planet10 said:
You going to do your FR125s?

That's the plan. I got "nato black" which looks like it will blend in rather stealthily. I don't know when I'll get around to doing them up though.

Was there a recommended pattern treatment for the phase plugs? I seem to recall something, but I couldn't find it on a search and I don't think I'm up for a read through of the entire EnAbl/Mamboni thread again.

Sorry about the threadjack folks.
 
maxro said:
That's the plan. I got "nato black" which looks like it will blend in rather stealthily. I don't know when I'll get around to doing them up though.

Was there a recommended pattern treatment for the phase plugs? I seem to recall something, but I couldn't find it on a search and I don't think I'm up for a read through of the entire EnAbl/Mamboni thread again.

Bud made passing reference to treating phase plugs in a post (don't know if it was in the enable thread).

The FRs do benefit an amazing amount with 2 vanishingly thing coats of C37. Th epuzzlecoat was almost as good, so i expect even just the benefit of the gloss coat will make a substantial improvement. You do have to be very careful not to get any coating into the voice coil gap (one of the reasons i'd choose C37 over PK for this driver. I have C37ed FRs here somewhere if you want to borrow them -- or bring your speaks out to the fest -- you coming?

dave
 
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