Yes, those measurements are from my own drivers.
So yes, the Radians have the capability of out-performing stock diaphragms.
So yes, the Radians have the capability of out-performing stock diaphragms.
Hi! I appreciate this is late, but I have a question that you maybe able to answer or lead me in the right direction.
I have coming out of Japan a pair of ec138 enclosures only. I have now accumulated all drivers except the 2235H woofers.
I have searched to try and find out what Attenuators are used on this model and where could I possibly get them ?
Considering they are a take off of the 4333a and L300's, my thoughts is they are the same !!! Can you shed some light ? many thanks
It'll depend on what crossovers you use with them
My unit was originally supplied with 3110a+3106 crossovers and these crossover units already have atteunators
If you plan on making your own crossovers, you'll need a 16ohm 100w and 8ohm 15w L-pads
https://www.parts-express.com/L-Pad-100W-Mono-1-Shaft-8-Ohm-260-265?quantity=1
https://www.parts-express.com/L-Pad-15W-Mono-3-8-Shaft-8-Ohm-260-248?quantity=1
Oh! Thank you... now all that makes sense. Here I am looking for the attenuators ( that sit in the top left corner ) thinking that i need them or by pass them altogether.
The stupid thing is I have coming the 3110a and the N8000 ( I believe it is the same as the 3106 ) and of course there is the rotary knob in the centre ( attenuator )
Plan was to install both networks and see how they perform. Leaving the option open to go active. So I gather I would need to plug the 2 holes that take the attenuators !
It does seem odd to have available both lots of attenuators, front 2 and 2 with the networks/crossovers.
I may take a look at the change you did with the 2405H tweeter after a listen.
The midrange I got ( designed with ) is the 2425J
Many thanks for your info, big help...actually saved me buying unnecessary attenuators.
Attachments
Yep, just seal those front atteunator holes
I see a top port missing , or you have them ?
Bottom port is 7" and top one is 11"
N8000 is meant for 8ohm midrange. You may want to use 2425H. While even 16ohm works, but it's response is different
I have a LE85 incoming . Will be doing le85 vs 2425h vs 2425h (with radian 1225) on 2307+2308
Only if these cabs were 2" deeper, could have used 2308
I see a top port missing , or you have them ?
Bottom port is 7" and top one is 11"
N8000 is meant for 8ohm midrange. You may want to use 2425H. While even 16ohm works, but it's response is different
I have a LE85 incoming . Will be doing le85 vs 2425h vs 2425h (with radian 1225) on 2307+2308
Only if these cabs were 2" deeper, could have used 2308
Well this is getting better all the time, thanks !
The cabs are as you see, must admit that top port had me thinking ( no do not have it, maybe inside the open cab ? ) if not will need to make one up, no biggy !
Thanks for the measurements. Wasn't sure whether one had to have both in place or could block one off, to change the bass !!! but then that would throw
out the tuning somewhat !
The other thing I see is the tweeter hole is sealed, why I do not know, again shouldn't be a problem to reopen.
In fact while this is all going on, I will check inside as all they ever put in these things was fibreglass wool. May dampen the inside walls and add bracing if needed
something JBL was not good at doing. all new wiring as well ( probably none there anyway ! )
Bugger and I thought the N8000 would work as they both cross at 8Khz but my 2425J is 16ohms.
Since I have that coming, I will try to find a 3106 to match up.
Yes the cabs are not as deep as the 4333a and L300.
In all it will be interesting once they arrive and put together.
Thanks again.
It's certainly going to be fun. Despite the shortcomings I keep coming back to JBLs for reasons I don't entirely know. I had ATC scm100 (with older tweeter) prior to JBLs, and despite ATCs measuring better, they just didn't have JBL energy
Also,
> N8000 = 3106 (also extremely easy to diy)
> For JBL2235 woofer + EC138 cabinet, Zilch's keeper network is easily better than 3110a. Smoother and less dark.
Also,
> N8000 = 3106 (also extremely easy to diy)
> For JBL2235 woofer + EC138 cabinet, Zilch's keeper network is easily better than 3110a. Smoother and less dark.
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Wow! okay ATC scm100 well sound and preferences is subjective. Prior to the ec138 yet to hear !!! will be my first JBL. I was going to build the L300 from scratch inc the Nelson Pass crossover until the ec138 rose it's head up ( totally unknown to me ) It was all about trying out 2 vintage classics inc amplification before jumping out of the rabbit hole. My current set is the Yamaha ns1000m fully restored driving them with the Willsenton R8 Int amp, the Accuphase e-206 and the Luxman L570'x class A Int.
Before it was all modern stuff like the Magnepan LRS, Triangle Comete 40th anni and DIY Troels Gravesen Revelator 851 which I still have.
So the ec138 will be quite interesting.
Okay will need to look up the Zilch's keeper network ( never heard of it )
Are you saying that one can covert the N8000 to a 3106 ? a mater of changing ???? it would save me buying the 3106 since I have n8000 coming. they are not
cheap to find.
Cheers.
IIRC N8000 and 3106 are the same units. So you're good with N8000, no need to get 3106
Zilch's Keeper: https://audiokarma.org/forums/index.php?threads/jbl-4333a-sansui-ec138.1037877/post-17129341
Zilch's Keeper: https://audiokarma.org/forums/index.php?threads/jbl-4333a-sansui-ec138.1037877/post-17129341
Thanks will follow up ( there is a lot to all this ! )
Didn't you say one sits at 8ohm and the other at 12-16 ohms ( My mid is the 2425J ( 16ohm )
Thanks.
Both 3106/N8000 are meant for 8ohm Midrange , 2425H
When using 2425J, 3106/N8000 will still be useable but may not be optimal
Your options:
> Replace Diaphragm on 2425J with JBL D8R2425
> Replace 3106/N8000 with 3105/N7000 . Although information is sketchy , but per this thread 3105/N7000 is optimal for 16ohm compression driver (2425J)
When using 2425J, 3106/N8000 will still be useable but may not be optimal
Your options:
> Replace Diaphragm on 2425J with JBL D8R2425
> Replace 3106/N8000 with 3105/N7000 . Although information is sketchy , but per this thread 3105/N7000 is optimal for 16ohm compression driver (2425J)
One more option, put a 16 (or 20) ohm resistor in parallel with the horn driver to reduce the impedience to ~8 ohms.
The fact of the matter is that in the later units, JBL would parallel a 20 ohm resistor on both the horn and tweeter anyway. I had also done this on my L200/300s but later took them off as I wanted them to play a bit lower in frequency and a higher impedience will let them do that.
BTW, the only difference between the early 7000 and 8000 crossover is the size of the inductor, 0.6 mH in the 7000 and 0.3 mH in the N8000. The pro versions 3106 (8000) adds the 20 ohm resistor.
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I have downloaded specs on all, 3110a, 3106, N8000, N7000, 3105... 2405H and 2425J.
It appears the best bet option is to take the 3105 with the 3110a ( which is coming anyway )
The unfortunate part for some reason people want the earth for them, may have to bite the bullet.
I have the N8000 coming as well, so will need to find a project for it Lol!
I have thought about the JBL or Sansui Le8t add a super tweeter like the 075 or 077 and use the n8000 to crossover.
Yes the N7000 crosses over at 7 Khz and the n8000 at 8KhzOne more option, put a 16 (or 20) ohm resistor in parallel with the horn driver to reduce the impedience to ~8 ohms.
The fact of the matter is that in the later units, JBL would parallel a 20 ohm resistor on both the horn and tweeter anyway. I had also done this on my L200/300s but later took them off as I wanted them to play a bit lower in frequency and a higher impedience will let them do that.
BTW, the only difference between the early 7000 and 8000 crossover is the size of the inductor, 0.6 mH in the 7000 and 0.3 mH in the N8000. The pro versions 3106 (8000) adds the 20 ohm resistor.
Not sure I would want to drop impedance down from 16 to 8 on the 2425J via the network, but a thought anyway considering I have the N8000 coming !!!!
Thanks for your input.
Learning from you heaps.
By the time it all arrives and set up, I may eventually go active ????? which will eliminate all crossovers and attenuators.
The rabbit hole just gets deeper :-(
Update:
> Acquired JBL 2420 pair (So the config is 2235 + 2420/HL91 + 2405)
> Made Zilch keeper network and been using for quite a whille
This setup sounds pretty good. Less sizzly 2405 and weightier midrange
However, I was always bothered with some veil in upper mids even with both lpads dialled to max. Bought a mic and ran some REW
1x Channel @1M (Mic positioned right between 2405 and HL91 Lens)
Both Channels combined from my listening position
That suckout from 5k-8k is what is making upper midrange muffled
All drivers are in positive polarity. Reversing polarity on 2420 makes suckout even worse and also introduces bit too energetic 1-2khz range
Zilch's driver placement vs EC138
Could driver placement be the reason Zilch's measurement doesn't have a suckout?
Any remediations to fix this with my driver config?
> Acquired JBL 2420 pair (So the config is 2235 + 2420/HL91 + 2405)
> Made Zilch keeper network and been using for quite a whille
This setup sounds pretty good. Less sizzly 2405 and weightier midrange
However, I was always bothered with some veil in upper mids even with both lpads dialled to max. Bought a mic and ran some REW
1x Channel @1M (Mic positioned right between 2405 and HL91 Lens)
Both Channels combined from my listening position
That suckout from 5k-8k is what is making upper midrange muffled
All drivers are in positive polarity. Reversing polarity on 2420 makes suckout even worse and also introduces bit too energetic 1-2khz range
Zilch's driver placement vs EC138
Could driver placement be the reason Zilch's measurement doesn't have a suckout?
Any remediations to fix this with my driver config?
Actually, the Zilch "Keeper Crossovers" were of my design, modified from a combination of the L200 crossover and the N7000/8000, that I built and subsequently sent to Zilch for his testing. I've always had a similar dip regardless of polarity. The dip is inherent in the tweeter and is the reason why JBL uses the "quasi-3rd order" combination that they do in the L300. Maybe modify the tweeter section to that of/similar to the L300/3133 to replicate the JBL solution.
I've never seen Zilch implement these or his test results and would love to see his results if you could point me to them.
BTW, this is partially why I went with the ESS AMT and developed the Mermans.
I've never seen Zilch implement these or his test results and would love to see his results if you could point me to them.
BTW, this is partially why I went with the ESS AMT and developed the Mermans.
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@toddalin Here you go:
Tweeter sections looks exactly as that of L300
Schematic:
https://www.audioheritage.org/vbull...woofer-changes&p=131390&viewfull=1#post131390
Measurements:
https://www.audioheritage.org/vbull...woofer-changes&p=130382&viewfull=1#post130382
Tweeter sections looks exactly as that of L300
Schematic:
https://www.audioheritage.org/vbull...woofer-changes&p=131390&viewfull=1#post131390
Measurements:
https://www.audioheritage.org/vbull...woofer-changes&p=130382&viewfull=1#post130382
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@Oyster150
To figure out what's going on, you'll need to run REW and capture a trace of the raw output of your 2420/H2307 combo .
- ( start the sweep at around 500hz at @ 85db, on axis, at 20" to the horn throat )
Compare your results to those of Zilch ( I posted his results earlier in the thread >> post 30 ).
If they are sort of ballpark to what I have just shown, then also capture a trace of your 2420/H2307 combo with the bandpass in place ( disconnect the woofer when you do the and replace with an 8ohm resistor >> also disconnect the tweeter and replace with a 10ohm resistor ).
Compare that newly acquired trace to what Zilch shows ( again, in post 30 ) when the band-pass is working and in place.
Did you look at the diaphragms when you purchased those 2420 drivers ?? Do you have any pics to share ??
To figure out what's going on, you'll need to run REW and capture a trace of the raw output of your 2420/H2307 combo .
- ( start the sweep at around 500hz at @ 85db, on axis, at 20" to the horn throat )
Compare your results to those of Zilch ( I posted his results earlier in the thread >> post 30 ).
If they are sort of ballpark to what I have just shown, then also capture a trace of your 2420/H2307 combo with the bandpass in place ( disconnect the woofer when you do the and replace with an 8ohm resistor >> also disconnect the tweeter and replace with a 10ohm resistor ).
Compare that newly acquired trace to what Zilch shows ( again, in post 30 ) when the band-pass is working and in place.
Did you look at the diaphragms when you purchased those 2420 drivers ?? Do you have any pics to share ??
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@EarlK While I did not capture pics of the diaphragm, I did open them up to replace dampening pads. The diaphragms appear to be original (dull aluminium with tangential edges). Foam pads were replaced with https://reconingspeakers.com/product/jbl-60398-24402445-damper-pad/ (cut to size)
Going to take raw measurements of the driver. That should tell if 2420 has got enough output
Going to take raw measurements of the driver. That should tell if 2420 has got enough output
This could be the difference. The tangential edge was the first design, similar to the 2215/LE175. It goes lower, warmer, but falls off on the top end compared to the later, and probably more common now, diamond edge. Perhaps the diamond edge provides a smoother transition to the 2405. This was then replaced by the titanium diamond edge in the 2425. Do we know which version Zilch was using?
BTW, all three of my 2420s also have original tangential edge diaphragms.
These are made of unobtanium.
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