Okay,
11th August is good.
This will give you some insights on the way the stock crossover is connected.
http://www.audioheritage.org/vbullet...ial&highlight=
If you plan to build new charge coupled crossovers (or get someone to do it) the wiring codes are in this thread which should reduce a lot of confusion.
There are some good example of that on the forums
The stock crossover loops the signal back from the L pads and then to the drivers.
That is a lot of press on connections and a lot of wire.
That and the rotary bi amp switch creates measurable insertion loss and an audible impact on sound quality.
If you really wanted you could remove the Mylar caps and put in something better.
(I put in SA Clarity caps bypassed by Auricaps .01) it's reputidly a good combination according to some users who wanted to go that route. You would also want to bypass the biamp switch and upgrade the binding posts.
There is not enough room for charge coupling on the original boards.
Has anyone tried using magnets to mount the grill badges? One of mine has fallen off. Looks the the previous owner might have tried a few different methods. I was thinking you could hot glue a thin piece of metal to the back of the badge and then us a magnet on the inside of the grill cloth? I think the badges are aluminum and aren't magnetic so you'd need to glue something to them to make it magnetic.
I don't see any harm in trying that. It could be, however, that even so little weight would pull the fabric enough to change how the light comes off it.
One speaker I had (I think it was the 4333a) used tie tack type studs going through a bracket mounted on the grille frame. You could apply your magnet idea in the same way, setting the bracket and magnet so the magnet just brushes the inside of the fabric. You'd have to make your own brackets, of course, so it could get a little complicated. Your method certainly worth trying first.
"Audio is filled with dangerous amateurs." --- Tim de Paravicini
Some trivia.
A few months ago we moved house to a new property and l was “told” they needed to be re decorated “before” they were coming inside the new house.
Well, l am 80% there and they are in the new AV room (mine). Unfortunately they won’t be going in main “pavillion” (hers) but perhaps it will be arranged for special occasions.
Now onto some more I interesting stuff.
There is an opportunity coming up to directly compare the 2122H mid cone with the 2123H in the 4345 enclosures.
If time permits l will solicit some subjective feedback from impartial “audiophile nuts” (and yours truly JBL loyalist but l am biased ...no pun intended).
The plan is to also arrange a ground plane frequency response measurement of both drivers and the system with LinearX LMS. What that means is it will be done outside and will be precise.
I will also trial my new discrete 2 way active crossover that can be calibrated for the specific bi amp requirements of the 43xx and the 44Xx Bi Radial series pro monitors. More on that in due course.
If there is sufficient interest l will post some details of the comparisons and evaluations.
Currently working on a 4345 DIY, using Tasmanian Oak veneer over high grade Euro Birch ply. CAD/CNC'd baffles.
Quality gathering of drivers.
Massive project to upgrade xover, using passive for top three channels, plus active bass.
Gryphon amps will be used.
The gent I'm building these for requested a brighter blue...called Dulux Wing Man. Ports to be painted blue.
I'm refitting the tweeter...so this is incorrectly shown in the photos.
Stands are 100mm tall in matching Oak veneer/trim.
I've had some preliminary listening sessions using my crappy small amps...and these speakers are sounding remarkable.
A wonderful project....not without complexity.
Andrew
Adjustable for top three channels. Active bass using DEX.
Just a heads up l will post a discussion comparing the 2122H and the 2123 soon.
Btw l auditioned the much talk about Dynaudio Focus 60XD today.
It’s a nice active loudspeaker. It has 4x 150 Watt amps per box and some serious dsp horse power.
RRP $15000+
I later played the same cds on my 4345 clones with a custom hi-end analogue active crossover and Pass Labs amps. The 4345’s completely blew away the 60XD on all fronts. Effortlessness, soundstage depth, instrumental clarity and vocal definition was in a completely different league. As they say nothing even comes close.
So don’t even think about trading your 4345’s anytime soon!
Hello Ian been there done that I am curious if we will reach the same conclusionJust a heads up l will post a discussion comparing the 2122H and the 2123 soon.
Rob
"I could be arguing in my spare time"
Well that saves me time and effort....Lol
What were your conclusions and how did you arrive at them?
As to been there done that you may have but many people are late to the party and they would no doubt be interested in your observations.
Here below is a simple near field spl measurement with the tip of the calibrated test mic 1 cm off the centre of the dust cap.
You can see the raw driver response in pink and the passive network response in brown. The divisions are 5 db.
The driver is remarkably smooth and is about -4 dB down at 1.5 khertz.
The passive filter is highly effective in attenuation of the break up modes at higher frequencies. The response is -30 dB down at 2 khertz and -4 db at 340 hertz.
I will try and post a comparison of the 2122 driver over the weekend.
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