My source bombed! She gave the sample back to me. She said she would be going to a trade show in Los Angeles late Spring early Summer and would take the sample with her then.
Giskard, isn't JBL using this same fabric for the 4344 MkII and others in Japan? Couldn't we try to source it through JBL Consumer?
Widget
Ooops, I forgot to check
Had a friend over for tea on Friday night and gave the system a stretch.
He played the Car mix version of a Sade album, well to cut a long story short I think I redefined the meaning of Slam.
It reminded me of Bulldog Brower the then strongest the westler in the world picking up Haystack Kalhoon all of 35 stone plus- the then heaviest wrestler in the world.
Not only did Bulldog Brower fully slam Haystacks Kalhoon he also caved in the whole ring and snapped it in half!!!!! Needless too say Haystacks did'nt get up..he was completely %^&*($.
That was a first.....and all recall Jack Little the comentator saying "Thats it folks, thats all there is, there is no more....LOL"
And so it is with the 4345's, be afraid, be very afraid.....
Ian
Last edited by Ian Mackenzie; 02-29-2004 at 01:56 AM.
Well Ian you obviously built them right because if you got on here posting how awful they were after you finished them then I would know immediately that catastrophic "user error" was involved
Excellent job
Na Na,
The only user error is on the knob on the Phase Linear 700B Series 2 when wound fully clockwise...the fine print says your f&^%$n "broken" mate.
Ian
Here is a new digital file a bit like one of the 4345 promotional 2 colour images....black..blue it does not matter.
Some trivia, I heard an odd resonance from the left channel the other night and was convinced the woofer was odd.
After changing out the driver and re foaming it I realised I have two room mode resonances at 40 and 50 hertz during a sweep tone test.....how unlucky and you be... well you live and learn.
Will need to hunt down a graphic or parametric EQ, moving the enclosures does not seem to help.
Ian
Last edited by Ian Mackenzie; 03-04-2004 at 12:07 PM.
Hello Ian
Sheet rock vibration or molding on the rattle?? I have a similar problem on my right side. In my case it was molding at the ceiling that had worked its way loose. Drove me nuts from my seat it sounded like it was inside my cabinet. Took a while to find it. 40 and 50 Hz are close how bad are the peaks??
Rob
Well now, that's what you get for using a crummy old 2245H woofer! I hear the entire city would resonate where it a SUB1500!!Originally posted by Ian Mackenzie
Will need to hunt down a graphic or parametric EQ, moving the enclosures does not seem to help.
You should have an EQ anyway, dood. Will really smarten-up the acoustic response. Nothing else quite like it. I'm running the dbx1231 - clean, flexible, parallel in and outs, both balanced and unbalanced. Full +/- 6dB (or 15dB switchable) of cut or boost. All I do is notch-out the badly behaved portions...
Are you sure it's the room, and not the cabinet? Hoping...
bo
"Indeed, not!!"
The room is rendering on brick but the left wall is some other construction like hard plaster board.
I am sure its not the box, and it can't be my clacka..that resonates a 17 cycles..square wave!
I swapped L/R last night, the left side of the room is odd, the right side is minor resonances .
I will exlpore this more over the long weekend and play with the oscillator and virtual ears to work out best enclosure placement.
Oh well another JBL weekend.
Ian
My wife hates it when I say that!Originally posted by Ian Mackenzie
Oh well another JBL weekend.
Ian
:shock:
But thats not a bad thing!
Well we all make Bloopers every now and then...this is mine.
Earlier I reported a strange resonance on the LHS of the room but could not figure it out properly.
Previously this baffled me......for fff'n days and nights...why did the RHS channel sound good...the LHS chesty and muffled?.....buggered if I knew and this was given me the willys
It sounded great the first few days....then hello what's that?
Well I left it alone and did the Formula One thing here a bit and came back to this issue arvo...and just decided to play some Madonna because I know the bass lines very well...and put my hand gently on the 2122 LHS cone while I was tweaking the Pad.
Hello.......why was it vibrating.......at low volume...that's strange.
So I changed out the woofer and checked the crossover.
There it was...a crocodile clip shunted across the 60 uf High Pass midrange filter.......SHIT.
The explanation.....
The other day I after the initial trials I did some phase tests just to be sure all 4 drivers were wired correctly...with 4 its easy to get it wrong.
Anyway to test the 2122 absolute phase I had to temporarily bypass the 60uf series HP capacitor and remove the 4.8 hm choke.....the driver was in correct phase so I then did the other channel.
The lighting was not the best and I re wired the choke ...but forgot to remove the crocodile jumper shorting the 60 uf mid filter on the left channel.
So there you have it....a JBL Blooper.....we all havem.
Back to researching the 4344 drawings....Ian
Last edited by Ian Mackenzie; 03-08-2004 at 01:22 AM.
This post possibly belongs in a tweak thread.
I recently played around with decoupling the 4345 cabinets from the floor to see what the effect was.
The cabinets sit atop a 2 inch kick base which is in direct contact with the floor. In my case this is carpet/underlay on 6 inches of conrete (reinforced I hope).
You would think concrete is dead and not prone to vibration..WONG. Its actually quite easy to get LF resonances with a slab.
At the time I was also considering various cabinet locations so I hit on the idea is using some 2 inch heavy duty castors and installed them on the inside perimeter of the kick base. The kick base now just clears the floor enough to enable the cabinets to be rolled around without to much effort.
The improvement in bass clarity is quite noticable on certain program material and this effect extends well into the midrange.
On recordings like The Eagles "Hell Fleezes Over" one of my favourite albums, the system appears more dynamic as there is more or less silence between the heavy bass transients, no overhang there at all now.
Considering the improvement I thought I would pass this tweek on. No doubt those Hi End tip toes or cones would also decouple the cabinets, but they are not very convenient if your WIFEY likes to vacum behind your second wife.
Being in a playful mood I also hooked up one of my diy baby class A amps. This one is rated about 35 watts 8 ohms and double again into 4 ohms. It cruises with a total of 9 amps bias current and and pair idle at about 300 watts....a small hair dryer tell the wifey.
"Hell Fleezes Over" never sounded so good..
Ian
Very Nice!
Very nice DIY Ian!!
Shane
Okay,
Here are some images of my 4345 cabinets with the authentic JBL Blue baffles.
Special thanks to Bo for so kindly assisting with the sourcing and colour matching, a difficult job and a fantastic result.
If we had an award for the most well liked and most generous Lansing Heritage Forum member, Bo would be the recipent.
The look in reality is quite impressive and I am sure they sound even sweeter. (no kidding).
Ian
ps A little touching up to be done in the ports , but is not obvious with normal lighting.
Last edited by Ian Mackenzie; 04-22-2004 at 05:48 AM.
Another angle
Ian
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