Need help with bass response

[invstbiker]

As previously mentioned, rec'd the "Paul B's" today, dusted them off and hooked them up. What I cannot understand is why the little shitter 4412's have better bass in my home than the big boy 4343's? These are not bi-amped (yet). Why is this and how can I get more bass out of these?

[Zilch]

You've pissed off the 4412's (my favorite bookshelf), so they're showin' you what they can REALLY do! :p

[Check the phase of your woofers with the ol' 1.5V battery test....]

[invstbiker]

Thx, Z, I'll give that a try. These came stock as far as I know, but will check it anyway. Missing the thunderous bass they are.

[norealtalent]

FWIW, out of 7 pair, not a one had good bass until bi-amped, then look out!

[invstbiker]

Hey Dude, Yea even my 4333's don't seem to have the bass punch as the little 4412's

[Audiobeer]

I have a Phase Linear 400 just like the one in your Pics! The speakers look gorgeous! I have never used the 400 other than to drive some 4313Bs. As that what you are using on the 4343s?

[edgewound]

Placement will be a big issue. It's not unusual that the smaller speakers have more "punch"...that's what you get with the 40-60 hz range.

The Big Boys will have more low end room shaking bass...but you gotta be in the right spot to hear/feel it. You are probably experiencing room modes with peaks and nulls. Stand up against the wall and you'll probably hear it. Ken Pachkowsky knows that well with his Westlake HR-1's when I heard them in his Palm Desert home.

You might need bass traps or at least different placement...such as diagonally across a corner so they're not firing into parallel walls.

[invstbiker]

Here's the current setup, a couple of MAC daddy's and a tube preamp by Audio Horizons. The PL 400 is awaiting the Ashley that I bought from Ken P. Then I'll do my first bi-amp setup. I do notice that when I stick my head into the hole between the 4343's where a tv could go, the bass is more pronounced, so maybe it's all placement, I'll have to play around with it but hate to open these cabs up just to check wiring. I have to presume it's correct coming from Paul B. He was the original owner. One refoam. Maybe the woofs are wired backwards when he replaced them? The singer imaging sounds correct. Smack dab in the middle.

[Steve Gonzales]

I wonder if when he switches to biamp mode on the crossover, if there still a coil/inductor in the LF circuit? If not, shouldn't he be able to do the battery test using the LF input terminals, without removing the woofers?. Dunno, just a thought.

Sweet lookin' set up there BTW.

[Robh3606]

On a woofer you have an Inductor in series. The battery test should work just fine. The hf drivers will be protected by the series caps.

Rob:)

[invstbiker]

Without re-opening the whole phase issue again. I just need a simple answer to:

I popped the woofer. I have a green w black strip wire going to the black terminal and a solid green wire going to the red terminal. I'm not finding a schematic, but know it's here someplace. Is this correct?

THX in advance

[johnaec]

Green/black going to black speaker terminal sounds normal. Even if it were out of phase in the cabinet, this would mainly be noticeable at the LF crossover frequency, and not the low bass response. To have phase affect the general LF output when both cabinets are operating, a more likely scenario would be that one cabinet LF driver were wired the reverse of the other cabinet - this would definitely affect LF perception with both cabinets operating.

John

[invstbiker]

Green with black stripe to black terminal
Solid green to red terminal

So they are correct in both cabinets. I'll have to play around with positioning. Like moving a Mack truck...

[4313B]

Put one of them where you have those 4412's and see what happens.

[johnaec]

Is there a chance the LF drivers are new recones and not broken in yet? Also, where do you have the crossover levels set at? On my 4315's, if they're all set to "0", the MF/HF/UHF are definitely too strong, making the LF sound weak. When I finally used an RTA to check the response, I was surprised how much I had to cut those levels to bring them in balance with the LF.

John

[Don Mascali]

I would still do the battery test.:)

[invstbiker]

This seems to help. I took 'em off the tiny plant stands and per Giskard put the right one into the tv hole. My wife agrees this helps with the "decorating nightmare" as she so bluntly puts it. John, When I got these the setting were all +++, so I backed them all down to zero. Now will turn them all off and bring them up one at a time, to see if this help more. BTW, what settings are yours at and do you rent out that RTA? :D

Thx fellas...

[toddalin]

Is it possible that what you are hearing is just a different frequency balance between the little and big guys?

If the 4312s fall off at the mids and highs compared to the big boys, especially if you have them exadurated, you end up turning up the volume further enhancing the bass and this could be perceived as enhanced bass response.

A sine wave generator and accurate sound level meter with linear weighting could tell if this were the case.

P.S. Send those 4350's over here and I'll check the bass for you compared to my L112's.;)

[invstbiker]

OH, and the woofs are refoams only

[invstbiker]

Hey Todd, The 50's are parked (literally) in the garage. I'm thinkin' about bringing them up to Sturgis at the bar. Just need to weigh the idiot-drunk factor :barf:

[Steve Gonzales]

You're gonna like them better when they are bi-amped. There will be alot more control over the LF at least.

[johnaec]

My 4315's are labeled +/- an extra line past 3 each direction. So I have UHF at - 3.5, HF at -2 and MF at 0. I'd suggest as you mentioned, turning them all down, then start with the LF at the volume you want. After that, bring each level control up to where it sounds balanced.

John

[invstbiker]

If we know the solid green is positive AND
green with black stripe is negative per JBL spec

AND the transducer clearly has a red and black terminal AND the wires are properly connected, what is a battery test going to tell me?

[jim campbell]

a barroom that allows smoking will destroy those 4350's faster than the drunks.smoke will get into everything.why waste a pair of those on a place where no one is listening anyway?

[invstbiker]

Jim, "thinkin' about it" are the key words. You're absolutely correct. However, this isn't your normal dark, dingy, smokey hole in the wall bar. We're talkin' 40 foot ceilings and open doors, etc. See the picture at www.oneeyedjackssaloon.com (http://www.oneeyedjackssaloon.com)

either way, I'd have to crane them up to the ceiling and that would be a hugh effort. I could just build a new house to accomodate them however...:D

[Steve Gonzales]

If we know the solid green is positive AND
green with black stripe is negative per JBL spec

AND the transducer clearly has a red and black terminal AND the wires are properly connected, what is a battery test going to tell me? A battery allows you to see the cone movement and judge the polarity. If a woofer is designed to move outward when given a positive charge applied to the + terminal, you can apply that with a battery. Example: take a 1.5v battery, connect wires from the + battery terminal to the + of the speaker and do the same for the -, If you do that to both speakers and you find that one of them moves the opposite direction, you know that they are wired out of phase and that will cause cancellation, especially in the LF region, amongst other things.

BTW, this is a momentary test, do not leave the battery hooked up, just touch it for a second. And please use a 1.5v, it's scary to use a 9v IMO

[invstbiker]

Thx Steve, I'll give it a try the next time I have use of the crane :D

Why would the woofs be internally wired incorrectly from the factory?

[Steve Gonzales]

I don't think that would be the case. If they have ever been removed for any reason, like a refoam, well, there is a chance, it happens to the best of us.

[invstbiker]

Well, Paul had them refoamed once to the best of my knowledge, so I do suppose anything is possible. Thx for the info!!

[Steve Gonzales]

You are very welcome Sir, you'll get it figured out and be lovin' them soon. i went through changes setting up my tri-amped system, but once I dialed it in, WOW! .

[Zilch]

If we know the solid green is positive AND
green with black stripe is negative per JBL spec

AND the transducer clearly has a red and black terminal AND the wires are properly connected, what is a battery test going to tell me?Disconnect the leads at the amp and apply the (+) of the battery to what you believe to be the postive polarity of the lead. The woofer will move either in or out.

Do it on each channel to verify that the systems are all connected in the correct phase. Both should move the same direction. It's just verification that everything is connected in phase. Even when I'm paying attention, I sometimes get it wrong.... ;)

Buy an RTA and learn how to use it. I'm convinced that few listeners without one have any clue as to how their systems are actually performing, or how to adjust them for proper balance.

[Yeah, I AM relentless about this. It's the best $250 I ever spent on audio.... :yes: ]

[Steve Gonzales]

A footnote to the polarity deal is that some woofers are designed to move in with the positive charge applied to the plus terminal so if indeed that is the case, and even if they are both moving in the same direction, you must also be sure that they are in proper phase with the rest of the system. I'm sure that there is someone here that can tell you what the correct movement of your particular woofers is.

[4313B]

Good grief! This is supposed to be the Technical Help forum. :banghead:

Let's start over.

1.) What I cannot understand is why the little 4412's have better bass in my home than the big boy 4343's?

Reverse the wires to one of the 4343's. If the LF response improves you have a polarity issue.

2.) These are not bi-amped (yet).

That is not your problem. Bi-amping makes a good situation better, it doesn't fix a bad situation.

3.) How can I get more bass out of these?

Move them until you get the LF response you want.

[Steve Gonzales]

Sorry about that Giskard, I didn't mean to imply that bi-amping would fix the problem.

[4313B]

Sorry about that Giskard, I didn't mean to imply that bi-amping would fix the problem.I was merely responding to his post. I'm not sure why he brought up the fact that they weren't bi-amped.

These are not bi-amped (yet).

[Steve Gonzales]

There have been two recent threads about the lack of LF performance here recently. This one and the 4435/B460. It must be frustrating to read all the glowing recommendations about them, only to find out that they apparently are not "plug and play".

[4313B]

I would imagine so. These guys aren't the first ones to have problems with their sound rooms. Some rooms work out just right to be all wrong for certain systems.

[Steve Gonzales]

I have been in and out of 3 different houses in the last year and wound up in one that by chance has wonderful acoustics. Same system ,basically, night and day difference. They're gonna have to drag my cold, dead corpse out of this one :D

[Ian Mackenzie]

Go back to the first picture. The most probably cause is not just the location of the 4343. Look what they are sitting on.

[chad]

Also - remember this:

Even if your cabinets are phased correctly and pass the battery test, you can still have one speaker cable (amp to cabinet) that is reversed.

[4313B]

Go back to the first picture. The most probably cause is not just the location of the 4343. Look what they are sitting on.I think he said he removed them at some point but I could be wrong.

I took 'em off the tiny plant stands

[Robh3606]

Put one of them where you have those 4412's and see what happens.


Yeah! :D Is that fireplace centered on a wall. If so look at where the 4412's are. There are on the centerline. If the fireplace is centered you are exciting one of the 3 primary axial modes in the room. Depending on what that is the 4412's will sound damn impressive but not at all smooth.

Rob:)

[Bernard Wolf]

Well, notwithstanding a RTA, Zilch.. I would be lost without my trusty test Lp which does channel identification as well as phase amongst other things. I test the treble and bass seperately and have been surprised more than once after mucking around with things. Think it cost me $2.00.

Bernard

[invstbiker]

OK, Guys, I can see how my simple threads get complicated. Here's what I have done so far.

1. No bi-amping (waiting for the ashley) I agree that biamping will not "fix" a problem for lack of bass.

2. I believe my room is fairly dampened. Carpet on the floor and furniture. I'm not going to buy sonic marketing.

3. I took the 43's off the puny plant stands, as they simply are to heavy for these. Now they just sit on the carpet, much easier to move around.

4. All the pots were at +3 when received from Paul B. They now are backed way down, this has improved the overall bass considerably.

5. Changed the overall positioning of the speakers themselves. One sits in the "tv hole" per Giskard. This has also helped.

6. Both green w/black stripe wires are confirmed going to the black terminal on the woofer. All wiring from amps double checked as correct. I have yet to do the "battery" test.

7. Don't get me wrong, this set sounds really nice, it's just that the 4412's had slightly more bass punch. My ears were used to them. My 4333's also "lacked " the bass punch of these little guys. I have yet to try the 4350's recently acquired, only 'caus I can't move them without a crane :D

8. I'm sure an RTA would help, Anybody have one "for rent" OR where does a person buy one? Recommendations please.

9. Not running a turntable so unable to test via LP

Other Than that, ALL is good on this Easter evening and hope alls well for everybody else as well!!

[invstbiker]

Rob, THe 4412's were simply sitting there, waiting for my back recovery to move them into storage. Werent even hooked up

[Zilch]

RTA - Behringer UltraCurve Pro DEQ2496. $250 at Guitar Center or your local pro sound dealer. Talk 'em into throwing in the $50 ECM8000 mic and cable for free. You'll also need XLR cables to hook it up, and a mini-boom mic stand, so count on spending $300 total for the complete setup....

[invstbiker]

Thank You sir for the rec!!

[Ian Mackenzie]

Hi,

About the smaller JBLs, are the connected to anything while in the room not playing? Might seem like a dumb question but unless they are shorted at the rear terminals or connected to an amp the 4343's will drive them like a passive radiator. Better still take them out of the room. Yes this is not a bunny joke.

If you have already done this please digregard this post..


OK, Guys, I can see how my simple threads get complicated. Here's what I have done so far.

1. No bi-amping (waiting for the ashley) I agree that biamping will not "fix" a problem for lack of bass.

2. I believe my room is fairly dampened. Carpet on the floor and furniture. I'm not going to buy sonic marketing.

3. I took the 43's off the puny plant stands, as they simply are to heavy for these. Now they just sit on the carpet, much easier to move around.

4. All the pots were at +3 when received from Paul B. They now are backed way down, this has improved the overall bass considerably.

5. Changed the overall positioning of the speakers themselves. One sits in the "tv hole" per Giskard. This has also helped.

6. Both green w/black stripe wires are confirmed going to the black terminal on the woofer. All wiring from amps double checked as correct. I have yet to do the "battery" test.

7. Don't get me wrong, this set sounds really nice, it's just that the 4412's had slightly more bass punch. My ears were used to them. My 4333's also "lacked " the bass punch of these little guys. I have yet to try the 4350's recently acquired, only 'caus I can't move them without a crane :D

8. I'm sure an RTA would help, Anybody have one "for rent" OR where does a person buy one? Recommendations please.

9. Not running a turntable so unable to test via LP

Other Than that, ALL is good on this Easter evening and hope alls well for everybody else as well!!

[4313B]

Are you going to fill that TV hole with something nice and big that will displace all that air space and create a nice flat surface for the 4343's to load up off? It doesn't look like a very fun room to try and set up big monitors in from that one picture. What are the dimensions again?

Have you moved around the room while listening to identify where the balanced spots are?

[Bernard Wolf]

9. Not running a turntable so unable to test via LP



Test CD's exist for the same purpose. I thought everyone had one of these :)... great for doing simple and easy verification tests. The one I have is put out by Stereophile. Maybe a friend of yours has one ?

[boputnam]

...and hooked them up. How?

Indulge me, but how is the crossover switch set on the rear?

[invstbiker]

Room dimensions are 23 * 19 with a 12 foot ceiling

Switch set to internal crossover on both speaks

[4313B]

It looks like a tough room... nice too.

[invstbiker]

Certainly not a studio...:D

[Robh3606]

What he said. Hey that's a nice looking room!!


Rob:)

[invstbiker]

Ya know, we could have a "help steve set up party" if anybody is in or coming to the greater phx area. :D Thank you

[edgewound]

Steve,

Great looking home. I know this might sound strange...but how do the speakers sound when you are in a different room? Big balanced bass as compared to the rest of the relative tonality? If so, keep moving them if possible to find the best location ( yeah...like that's easy). Usually that's diagonal across a corner so they're not firing into parallel walls...causing cancellations(nulls). If you stand right against a wall, I bet you'll hear plenty of bass.

[invstbiker]

Thank you, My wife and I love the "new" place. If I stick my head in the tv hole where the right speaker is, there is plenty of deep bass. None of this is "bad". Now, I believe it is a matter of fine tuning. I'll get to audio nirvana soon. That's the fun part of this hobby. :)

[4313B]

If I stick my head in the tv hole where the right speaker is, there is plenty of deep bass.No doubt...

[invstbiker]

I just picked up one of these gems.(ebay) This unit has a built in phase checker, so plugged it in and low and behold if my left channel was out of phase. Now, I have to say that right now, until I bi-amp, the left channel wire is spliced because I was too cheap to go buy some new wire..:blink: (The Canare is en-route.) BEFORE switching anything around, I double checked my wiring and I found it to be correct. So I then switched the wires where they are spliced, turned it back on and the Phonic now says the left channel is in phase. The bass has really picked up :D . So, I have to assume that a transducer is incorrectly wired. Next step is to return the spliced wire back to correct and then switch the wires on the woofer and recheck. Hopefully that will show in phase, I'll report my findings.

[4313B]

You're supposed to find that out after we have you bust holes in a couple of walls to flush mount them. :scold:

[invstbiker]

I know, movin' the 501 Macdaddys is tough enough, My wife would love these 43's built in, that would solve the "decorating" nightmare she's struggling with...

[invstbiker]

OK, I reinstated the external wiring back to what I know is correct AND swapped the internal wires on the woofer for the left channel. Plugged in the Phonic and all is now in phase and sounds great. So, the Green w/ black stripe wire is now on the + terminal and the solid green is on the - terminal which is backasswards per spec. My question is now... how in the hell could the polarity get reversed on this one woofer and the only known repair through it's history is a refoam? Original factory error?

[Zilch]

Check how the other woofer is hooked up....

[invstbiker]

The other woofer is per spec. Green w/ black wire to - terminal
Solid Green to + terminal

[Audiobeer]

That's strange as hell! :(

[CONVERGENCE]

This question is recurring all the time. My answer is buy a sub use your speakers as mid bass. With todays CD more bass is encoded with more DB in the recordings.The old vynils had a cut off at 100Hz in mono.

Here is a good choice for 20Hz to 85Hz then switch
your speakers >85 HZ


http://www.jblpro.com/pub/cinema/4641.pdf


.................................................. ...................................

[Zilch]

Well, we're back where we started:

Battery test both woofers. ;)

Phonic's reading (+) polarity, I betcha....

[invstbiker]

OK, I'll do the battery test and post my findings...

[grumpy]

If the battery test doesn't show a polarity problem with the bass driver terminals, you
might want to just trace -all- of the internal wires: input terminals to crossover,
then to each driver...

-grumpy

[invstbiker]

Here's a pic of my "battery testing lab". Now this may be off post so I will re-post new for others to see as well.

I checked the polarity of the woofer in question and son-of-a-gun if it isn't wired back-ass-wards. (or the terminals were reversed) When I apply the + to + and the - to - the cone moves inward. When I switch them around the cone moves outward. So the mystery has been solved, thank you Z-Man for the urgency of doing the batt check. My Phonic was right on too. The bass has improved along with the imaging. Much better.

I would still like to know how this could have happened. Maybe the terminals got switched at some point? I wouldn't think a refoam would have anything to do with it?

[toddalin]

I checked the polarity of the woofer in question and son-of-a-gun if it isn't wired back-ass-wards. (or the terminals were reversed) When I apply the + to + and the - to - the cone moves inward. When I switch them around the cone moves outward.

It's supposed to work that way. If the other cone is moving outward on a + to +, it's backward.

[Mr. Widget]

JBL has been out of phase with virtually every other manufacturer of loudspeakers for decades, though they finally changed and now they share the same polarity as the rest of the speaker world.

http://www.jblpro.com/tech-library/JBL_TechNoteN1V12C_v5.pdf

It is one of Bo's favorite topics and it has been discussed a lot. If you are bored one night do some "polarity" searches.


Widget

[invstbiker]

Well this is really getting confusing now...

[Steve Gonzales]

A footnote to the polarity deal is that some woofers are designed to move in with the positive charge applied to the plus terminal so if indeed that is the case, and even if they are both moving in the same direction, you must also be sure that they are in proper phase with the rest of the system. I'm sure that there is someone here that can tell you what the correct movement of your particular woofers is. Now that you know that they were out of phase in respect to each other, you can fix your pair.

[Mr. Widget]

Well this is really getting confusing now...If you read the JBL Pro link I posted, it clears it up pretty well.


Widget

[invstbiker]

Yes, Thank you sir, it did help. Not to beat a dead horse anylonger , my Phonic tells me both speakers are now "in phase", it sounds good" So I'll keep it as is and enjoy the music...

[Don Mascali]

So I'll keep it as is and enjoy the music...


Thats what it's all about. Crank them puppies up and enjoy.:applaud:

[Zilch]

Now that you know that they were out of phase in respect to each other, you can fix your pair.


Not to beat a dead horse anylonger , my Phonic tells me both speakers are now "in phase", it sounds good" So I'll keep it as is and enjoy the music...


Thats what it's all about. Crank them puppies up and enjoy.:applaud:

While the lure of refreshing beverages may be compelling, y'all are quittin' much too soon.

We now have one woofer wired backwards, as the battery test revealed it was connected correctly, according to JBL convention. So, now, the phasing is incorrect with the other drivers in that cabinet.

Battery check the other woofer, and the fact that something else is still connected wrongly will be revealed.... :)

What's the system? 4343? Time to check the schematic to see how it's s'posed to be wired with respect to phase/polarity....

EDIT: Yup, unless I'm reading it wrong, woofer's supposed to be out-of-phase with the other three drivers. Follow the black input connections here:

http://www.jblproservice.com/pdf/Network%20Schematics/3143%20Network.pdf

[Phonic don't know that, OR the JBL polarity convention....]

[invstbiker]

OK, ZMAN, I'm backin' up the crane, and will break out the flashlight and check all wiring, etc...

[edgewound]

OK, ZMAN, I'm backin' up the crane, and will break out the flashlight and check all wiring, etc...


I will check the other componants. I am to assume that all solid color leads go to + terminals. So if another one is reversed on the mid, HF or tweeter, that could screw this all up as well. I'll check it out, I love playing with my crane...:D

The positive terminal is black. "Positive voltage applied to the black terminal will cause outward cone/diaphragm movement".

Crossover networks are wired so as to keep the phase correct based on the network topology. Black striped wire from each crossover output goes to black terminal on each driver, solid wire goes to red driver terminal. Yellow pair is HF, white pair is MF, green pair is LF.

Then do the battery check on the system inputs. Black is still positive. If a cone moves in when positive voltage is applied to black speaker system input, something is miswired internally....possibly at the crossover's input from the external terminals. The red and black crossover input wires should match the red and black system input terminals.

[invstbiker]

THANK YOU, I will try this first

[Bernard Wolf]

THANK YOU, I will try this first

Man.. I sure hope there isn't a lake too close to where you live..:blink: I'd be in it by now !! :) .. Hang in there, you'll get it right eventually.

[invstbiker]

See my post on DIY

Battery Test Re-Dux

Thanks to all

[B&KMan]

As previously mentioned, rec'd the "Paul B's" today, dusted them off and hooked them up. What I cannot understand is why the little shitter 4412's have better bass in my home than the big boy 4343's? These are not bi-amped (yet). Why is this and how can I get more bass out of these?

Sorry for my poor english but I smell a couple of idea to help you.

First your wood stand under 4343 is bad principe and unstabilize the speaker.

2-- the speakers is go down freq realy more than 4412 so more exication of modal room is created : and it is more tricky to position in room.

3-- your 4412 is a Bazooka set-up you put in cavity so the pressure is upper strongly... (try to invert position with your big 4343)

4-- dont minimize the realy realy problem to the #$%%?%??&?&*?&* old used switch on back 4343 to permit to switch bi amp is created a really loose response and power ( manys guy expose this problem and in first the great master greg Timber) (I personnaly exposed the difference result mesure in thread 4343 network modification.)

5-- the calibration of the rest of L-pad determine the importance to feeling of snap bass by tinuing balance sound.

6-- push up your big 4343 in more inch of the floor, according to greg timber the midbass is less flat.

7 --- :cheers:

[invstbiker]

Thank you for that B&K, my 43's are just on the floor now, but probably need to be on a correct stand which I am searching for.

[B&KMan]

The other woofer is per spec. Green w/ black wire to - terminal
Solid Green to + terminal

OH NO !!!!

Eternal drama...


I'm called JBL In california headquarter on this question and the red post is really positive signal and black is negative signal...

the reason why the driver is move backward is the coil is wired inverse way than standart. so your 15" inch driver is normally backward if correct connected.

so: it is not a circontantial error...

but check the rest of the drivers according to original spec...

p.s. your top upgrade 4343 is the cancellation of the bi-amp switch on back. this is a major lack of sound .

:cheers:

[B&KMan]

4-- dont minimize the realy realy problem to the #$%%?%??&?&*?&* old used switch on back 4343 to permit to switch bi amp is created a really loose response and power ( manys guy expose this problem and in first the great master greg Timber) (I personnaly exposed the difference result mesure in thread 4343 network modification.)


here : the test difference after (upper graph) and before cancel switch of bi-amp on back of the 4343


http://www.audioheritage.org/vbulletin/showpost.php?p=52144&postcount=113

[B&KMan]

Thank you for that B&K, my 43's are just on the floor now, but probably need to be on a correct stand which I am searching for.

the rule is simple : hard as possible and maximum weight & stability stand create a real better transfert impact and less coloration.

I invite you to keep a few time to explore many many points on this regards and in regards of you 4343...
this forum is really plenty questions and solutions in regards of your 4343.


:cheers:

[invstbiker]

FWIW, out of 7 pair, not a one had good bass until bi-amped, then look out!

Today was the day that Bi-amping took place in my home. Kinda like the first kiss thing. :bouncy: Last week, after "fixing" the phasing challenge and last night re-wiring female XLR to male RCA for my phase linear, I was ready to go. A BIG THANK YOU :applaud: to KEN P. who not only supplied the Ashly crossover but helped me with the dang wiring. I know some of you guys are thinkin' no big deal but to the beginner, it's a big deal. Just remember your roots...:D When I first turned it all on, (kinda like launching a spacecraft) the whole thing sounded a bit strange, THEN after tweaking the Ashly controls and turning down the midrange on the 43's....

:jawdrop: :jawdrop: :jawdrop: TRIPLE JAW DROP. Holy shit, I'm never going back to internal crossovers again. Even the wife said "honey, your system sounds really good" Well that's a first. The BASS is really there!! I'm a happy camper. Next up is to try my "new" 4350's (break out the crane boys)

"It just won't end" Happy beer thirty to all.............

[Ken Pachkowsky]

Enjoy the new crossover. You no doubt will.

Ken

[Robh3606]

So another biamp convert! Those woofers sound good with no passives in line. Glad you like it. Might be "beer o clock" for a while though as you go through your CD's. It was a little intimidating for me too the first time but once you have done it it's not so bad.

Rob:)

[Rudy Kleimann]

... Last week, after "fixing" the phasing challenge and last night re-wiring female XLR to male RCA for my phase linear, I was ready to go....

One thing I feel should be mentioned: If the crossovers are wired the same in both cabinets (almost certainly they ARE), the drivers are connected the same in both cabinets, and the problem persisted, then it leaves one of three possibilities IMHO:

1:One of the woofers has the red and the black push terminals swapped

2:One of the woofers has been reconed with a non-standard aftermarket coil (NOT a JBL recone kit).

3:One of the amplifiers is inverting phase from input signal to power amp output. It can happen! Could be a phase invert switch flipped on the amp, or one amp was altered. Your Phonic phase checker can help you ferret this out. If nothing else, swap speakers on the same amp and see if the other speaker does this too.

Regarding "JBL polarity convention", almost all of the older JBL woofers (and the systems they are used in) ARE "reverse polarity". The woofer goes in with + to red on both the woofer itself AND when applied to the input terminals on the back of the cabinet. This is the reverse of "absolute phase", meaning positive voltage should create positive air pressure by the woofer -not negative pressure (vacuum).

The simple fix (and correct one IMHO) is to connect your amplifier speaker cables with amp Red to speaker Black terminal on BOTH JBL cabinets. This gets 'em in sync with the world.;)

Otherwise, if you ever add other speaker systems that are "Normal phase convention" to the mix, you'll have the same confusing headache all over again.

[invstbiker]

One thing I feel should be mentioned: If the crossovers are wired the same in both cabinets (almost certainly they ARE), the drivers are connected the same in both cabinets, and the problem persisted, then it leaves one of three possibilities IMHO:

1:One of the woofers has the red and the black push terminals swapped

2:One of the woofers has been reconed with a non-standard aftermarket coil (NOT a JBL recone kit).

3:One of the amplifiers is inverting phase from input signal to power amp output. It can happen! Could be a phase invert switch flipped on the amp, or one amp was altered. Your Phonic phase checker can help you ferret this out. If nothing else, swap speakers on the same amp and see if the other speaker does this too.

Regarding "JBL polarity convention", almost all of the older JBL woofers (and the systems they are used in) ARE "reverse polarity". The woofer goes in with + to red on both the woofer itself AND when applied to the input terminals on the back of the cabinet. This is the reverse of "absolute phase", meaning positive voltage should create positive air pressure by the woofer -not negative pressure (vacuum).

The simple fix (and correct one IMHO) is to connect your amplifier speaker cables with amp Red to speaker Black terminal on BOTH JBL cabinets. This gets 'em in sync with the world.;)

Otherwise, if you ever add other speaker systems that are "Normal phase convention" to the mix, you'll have the same confusing headache all over again.

IT'S ALL GOOD NOW :D

[boputnam]

2:One of the woofers has been reconed with a non-standard aftermarket coil (NOT a JBL recone kit).I thought that was mentioned, but maybe not - these have not been reconed, I believe.



Regarding "JBL polarity convention", almost all of the older JBL woofers (and the systems they are used in) ARE "reverse polarity". The woofer goes in with + to red on both the woofer itself AND when applied to the input terminals on the back of the cabinet. This is the reverse of "absolute phase", meaning positive voltage should create positive air pressure by the woofer - not negative pressure (vacuum).

The simple fix (and correct one IMHO) is to connect your amplifier speaker cables with amp Red to speaker Black terminal on BOTH JBL cabinets. This gets 'em in sync with the world.;)

As Giskard posted a few years back, we all know JBL suck - it's the rest of the old world that had the polarity wrong! But it doesn't matter at all in bass reproduction or frequency response - that is a misconception.


Otherwise, if you ever add other speaker systems that are "Normal phase convention" to the mix, you'll have the same confusing headache all over again.Now then it DOES matter. But, these are loyal JBL fans and very few pair cabinets of other brands, or even multiple JBL without checking inter-cabinet element polarity.

-----

Doods - having two threads on this same topic is exhausting. I'm getting worse callouses than my guitar player... :blink:

[invstbiker]

I thought that was mentioned, but maybe not - these have not been reconed, I believe.

Doods - having two threads on this same topic is exhausting. I'm getting worse callouses than my guitar player... :blink:

Correct re-foam only. Shoulda booted that battery redux thread when you had the chance...:D

[boputnam]

This is the reverse of "absolute polarity", meaning positive voltage should create positive air pressure by the woofer - not negative pressure (vacuum). It's a sine wave, man. What do you think the woofers are doing half the time, either way...? ;)

[Rudy Kleimann]

It's a sine wave, man. What do you think the woofers are doing half the time, either way...? ;)

I understand what you are saying.

Best way I can describe it is this:

Whan I was a kid, I came upon an abandoned TV Set. Typical boy, I had to mess with it. Eventually, I smashed the picture tube. The implosion of the tube caused by the vacuum inside made a unique sound that I have never forgotten. It was competely different than, say, a firecracker or a gunshot.

Or, a drum set? The attack of a wind instrument? The human voice?

If you don't hear the difference, it doesn't matter. If you do...

[boputnam]

Or, a drum set? The only time I've noticed this, is on the Kit. If the mains are out-of-phase with the kick, snare, toms, there can be cancellations - but these are wave form cancellations, not an issue of whether it sounds "real".

I know some guys in monitorworld reverse phase on the kick mic (like a SM52), to feed it back to the drummer boy so his wedge is phased with the skin motion. Some say they can hear the kick better - that the wedge is not being cancelled by the kick wave form. I don't know. Best to keep the artists happy, though... :)

But otherwise, unless there is wave-form cancellation... :no:


The attack of a wind instrument? The human voice?
Actually these sounds you refer to are dominantly in the frequency range of the MF (3-way cabinet) or compression driver / horn (two-way cabinet). In these cabinets, elements are phased differently than the LF. So, even if, in your "absolute polarity" world these sounds would be coming from elements that are moving in opposing directions to the woofer cone, i.e., their diaphragms would be going in on (+) signal, when the woofer cone is excurting (is that a word...? :blink: ) out on (+).

[Rudy Kleimann]

Not on gigs- on my Martin-Logans here at home. Hell I've got enough things to handle at a gig without giving any thoughts to that...:band:

[invstbiker]

Today is the first day I've been able to recheck the phasing issue I previously had, now that I'm bi-amped. Here's what I have setup. The phase linear is running the top end and the Macs are running the 2231's only. Phonic testing the top end only, both left and right are in phase. Running the Macs only, the left channel only is not in phase (again)..:banghead: I swapped the leads on the back of the left speaker, bottom end only and it now reads in phase. I am no longer running spliced speaker wire. The only other thing I added was the Ashly Xover/. Since I'm headed to SD soon, I'm gonna just leave it 'cause I don't have any more time to fool with it. Actually, it sounds fantastic, so I believe I'm just gonna leave it, period. Pain in the ass it is...:D

[boputnam]

...the Macs...Man, I wish you'd call those "Mc's" - I keep thinking there is something Mackie in there... :barf:

Overall this is good news.
1 - The cabinets are consistent, it seems.
2 - You can hear the impact(s) of running two cabinets out-of-phase.
3 - You are liking the improvements.

There must be some connection wired wrong, is all. Try and label everything - both ends - and double-check that none of the balanced cables are confusing Pin2 and Pin3 - that can happen...

[invstbiker]

Man, I wish you'd call those "Mc's" - I keep thinking there is something Mackie in there... :barf:

Overall this is good news.
1 - The cabinets are consistent, it seems.
2 - You can hear the impact(s) of running two cabinets out-of-phase.
3 - You are liking the improvements.

There must be some connection wired wrong, is all. Try and label everything - both ends - and double-check that none of the balanced cables are confusing Pin2 and Pin3 - that can happen...

OK, How 'bout MacDaddys'...:D ? 90lbs each

1. Cabs are consistant
2. I cannot hear any difference
3. I'm running the leads backassward on the left 2231 only as my phonic tells me this is in phase.

XLR cables, maybe something there, but I'd have to rip the whole thing apart and right now, no can do. When I get back from Sturgis, in Sept, I'll give that a try....Thx BO

[invstbiker]

Here's my newest revelation regarding the above referenced title. I just went bi-amped and love it. I have a couple of questions and comments. On the 4343's, the bass driver (2231A) is a negative transducer meaning when I apply the battery test, the cone moves out when the + battery is contacted with the - terminal on the transducer. This we know. Q? When using an external Xover and switching to external crossover on the rear of the speaker, is the bass driver isolated from the internal crossover? I have swapped leads on both bass drivers and now have the + lead going to the - terminal on the speaker and so forth. My Phonic Phase tester (EBAY $350.00) playing just the bass only, one channel at a time tells me that my bass transducers are both IN PHASE. Testing the top end only, one channel at a time again I am IN PHASE whereby + is + and - is -. So now, my whole system is IN PHASE per Phonic. When I switch the leads on the bass drivers only whereby + is + and - is -, the Phonic reads Not in phase. Does anybody else have this situation?

[boputnam]

When ... switching to external crossover on the rear of the speaker, is the bass driver isolated from the internal crossover?Yes, completely. Check the schematic - you'll see how.

[boputnam]

When I switch the leads on the bass drivers only whereby + is + and - is -, the Phonic reads Not in phase. Does anybody else have this situation?I'm starting to get confused... :spin:

I think what is confusing you - but I might be confused in what you are observing - is that when the cabinets are wired the way JBL intended, the woofers are opposite the polarity of the rest of the cabinet. This response is confusing the Phonic which is seeing the different polarity as "wrong". It is not wrong, it is correct by design.

I've not used the Phonic, but can you hold it RIGHT UP in the woofers to check only them, and then do likewise with the other transducers?

If you had the Galaxy Cricket, it would tell you the woofs are (-) and all the others are (+). That is good. That is what JBL designed for that network.

[invstbiker]

If this is the case, then all (neg) bass transducers need to be wired unconventionally to be in proper phase. That is the + lead to the - low frequency terminal. That's what my Phonic tells me anyway. I'm all IN PHASE now with this wiring. And it sounds DAMN good!

[Zilch]

If you go back to the original thread on this, I believe you'll find that that woofers are supposed to operate out-of-phase with the other drivers on the schematic. Follow the black leads there.

Why? Because JBL determined doing that produced the desired acoustic transitions between/among the drivers, in the context of their physical alignment and the passive crossover topology built into the system.

When biamping, you must make your own determination according to the differences that might be inherent in whatever external crossover you are using. Your RTA can help with this, but listening is the final determinant.

Read up on biamp phasing in the 5235 manual, for example....

[invstbiker]

I'm starting to get confused... :spin:

I think what is confusing you - but I might be confused in what you are observing - is that when the cabinets are wired the way JBL intended, the woofers are opposite the polarity of the rest of the cabinet. This response is confusing the Phonic which is seeing the different polarity as "wrong". It is not wrong, it is correct by design.

I've not used the Phonic, but can you hold it RIGHT UP in the woofers to check only them, and then do likewise with the other transducers?

If you had the Galaxy Cricket, it would tell you the woofs are (-) and all the others are (+). That is good. That is what JBL designed for that network.

NOW that makes sense, If this is JBLS's intention, then the Phonic SHOULD READ not in phase and is reading it correctly. PERFECT!!:applaud: GEEZ. And Yes I can check Low end, High end, Left and right all separately. That's worth a drink right there.:bouncy: Thank you!! GEEZ I can finally end the 2 am thinking about this. Now it's happening!!

[invstbiker]

If you go back to the original thread on this, I believe you'll find that that woofers are supposed to operate out-of-phase with the other drivers on the schematic. Follow the black leads there.

Why? Because JBL determined doing that produced the desired acoustic transitions between/among the drivers, in the context of their physical alignment and the passive crossover topology built into the system.

When biamping, you must make your own determination according to the differences that might be inherent in whatever external crossover you are using. Your RTA can help with this, but listening is the final determinant.

Read up on biamp phasing in the 5235 manual, for example....

NOW it makes sense, just takes me a little longer....Thank You!!

[boputnam]

Yes I can check Low end, High end, Left and right all separately. Good.

For the polarity test, use the Phonic up close - right at the transducer you are checking.

You should get:
UHF = (+)
HF = (+)
MF = (+)
LF = (-)

Man, if we finally got there, you should be very pleased with the bass response.

Zilch'ster - thanks for sticking with this!! :applaud:

-----

One thing on the Ashly XR1001: the decal markings on the front are not very precise. On mine, I find that I need to set the frequency just a bit below what is marked on the face to be at the desired point. You could check this using your Phonic.

Mute the HF outputs on the Ashly. Using only the LF outputs, use the Phonic RTA. You will see the frequency response curve slope off. Dial the xover point slowly and watch the curve change. Listen, and watch the RTA - you may be able to pin-point the right setting. I don't know if the RTA's resolution is sufficient to really see what is going on, but maybe.

[invstbiker]

Good.

For the polarity test, use the Phonic up close - right at the transducer you are checking.

You should get:
UHF = (+)
HF = (+)
MF = (+)
LF = (-)

Man, if we finally got there, you should be very pleased with the bass response.

Zilch'ster - thanks for sticking with this!! :applaud:

-----

One thing on the Ashly XR1001: the decal markings on the front are not very precise. On mine, I find that I need to set the frequency just a bit below what is marked on the face to be at the desired point. You could check this using your Phonic.

Mute the HF outputs on the Ashly. Using only the LF outputs, use the Phonic RTA. You will see the frequency response curve slope off. Dial the xover point slowly and watch the curve change. Listen, and watch the RTA - you may be able to pin-point the right setting. I don't know if the RTA's resolution is sufficient to really see what is going on, but maybe.

This is exactly what I have now. Thank God it's over :bouncy: whew. Now just enjoy the music..:applaud:

[edgewound]

All through this exercise it's still important to know that all 4300/4400 series studio monitors and L-Series home speakers, with the exception of 4311 and 4312, are positive to black input terminal.

[invstbiker]

Why? Because JBL determined doing that produced the desired acoustic transitions between/among the drivers, in the context of their physical alignment and the passive crossover topology built into the system.

When biamping, you must make your own determination according to the differences that might be inherent in whatever external crossover you are using. Your RTA can help with this, but listening is the final determinant.



I just did several A/B comparisons with different pieces of material and I've gotta tell you, I get better bass response when the woofs are wired back asswards making it "IN PHASE" vs. out of phase with the other transducers. "listening is the final determinant" I agree...

[boputnam]

I get better bass response when the woofs are wired back asswards making it "IN PHASE" vs. out of phase with the other transducers. "listening is the final determinant" I agree...With them wired that way, you are getting a doubling of the frequencies in the area of the crossover point between the LF and MF. I don't know the exact range, but guess it is between say 200Hz and 400Hz. The slope on the Ashly is -24dB, but I think the passive network is -12dB, so there could be a considerable area of summing.

If you like that, cool. However, you may find that while there is "more bass", it is not as distinct tonally as with the LF opposite. Keep us posted...

[boputnam]

...positive to black input terminal.This got me thinking, invstbiker - you face one hell of a quandry.

Going with this, you'll get:

JBL spec
UHF = (-)
HF = (-)
MF = (-)
LF = (+)

invstbiker way
UHF = (-)
HF = (-)
MF = (-)
LF = (-)

The whole thing will suck. Your eyeballs will pop out of your head!

Remember what Giskard used to say - "it's all fun and games until someone loses an eye...!"

:rotfl:

[invstbiker]

This got me thinking, invstbiker - you face one hell of a quandry.

Going with this, you'll get:

JBL spec
UHF = (-)
HF = (-)
MF = (-)
LF = (+)

invstbiker way
UHF = (-)
HF = (-)
MF = (-)
LF = (-)

The whole thing will suck. Your eyeballs will pop out of your head!

Remember what Giskard used to say - "it's all fun and games until someone loses an eye...!"

:rotfl:

Correction, I have all

UHF = +
HF = +
MF = +
LF = +

The only difference is the LF. The JBL way has the LF = - when I switch this one only, I get it + thereby all are in phase, not out of phase. If I follow the Edgewound way, I get a better kick out of the LF

[boputnam]

Ah...

[Mr. Widget]

Bo asked me to merge the Phase thread with the Bass thread as they are a bit intertwined... hope this makes sense.


Widget

[invstbiker]

Bo asked me to merge the Phase thread with the Bass thread as they are a bit intertwined... hope this makes sense.
Widget

Perfectly

[Mr. Widget]

I'm starting to get confused... :spin:I got confused awhile back too...

All this phase/polarity stuff shouldn't be all that complicated. Has anyone mentioned that some amps are inverting and others are not? This may have already been looked into or not... and it may or may not be relevant. I hope you get this whole thing figured out.


Widget

[invstbiker]

I got confused awhile back too...

All this phase/polarity stuff shouldn't be all that complicated. Has anyone mentioned that some amps are inverting and others are not? This may have already been looked into or not... and it may or may not be relevant. I hope you get this whole thing figured out.


Widget

I'm confident that I have it all correct now. All my top end is "IN PHASE" and rather than having the woofer "OUT of PHASE" as JBL intended it, I have that "IN PHASE" as well. I get better bass response this way. I'd rather have it all "IN PHASE" rather than a combo plan. Thank You

[boputnam]

Do you still have that Phonic thingy out?

I know they're all the same now - as your preference - but I'm curious what all the elements read now... :hmm:

If they are all (+), then you must not have wired the "tops" with positive to black, like edge posted.

[invstbiker]

Bo, All transducers read IN PHASE +

Remember, the only leads that I reversed are the LF, the top end is still +=+ and -=-

If you swap your low end leads, your bass will really pop. Just a preference at this point. I'm still listening...

[boputnam]

Bo, All transducers read IN PHASE +

Remember, the only leads that I reversed are the LF, the top end is still +=+ and -=-

If you swap your low end leads, your bass will really pop.Got it - exactly what I thought.

The positive to Red or Black doesn't matter so long as you are in the privacy of your own home and not pairing with anything. You can imagine the struggle internal within JBL when they decided to go with the "AES standard" which post-dated their pioneering work...:( .Anyway, if you are going positive to Red on the tops you're just "old school" (:wave:) - there's no difference in response. :no:

I don't think I'll "reverse" anything. I'm (so far... ;) ) sticking with the age-old design.

As I told you by pm - in response to your donation to LH site!! :cheers: - it's really cool you're happy with the outcome. We've all learn a lot in the sharing, here. Thanks, Widget for merging these - it maintains the continuity of the project.

[invstbiker]

:thmbsup: :thmbsup: It's been a hell of a ride...I'm just happy with the outcome and the fact that I'm not having to deal with other brands all mixed in. That would really create havoc in my brain...I'm stickin' with the vintage gear.

[edgewound]

Bo...

Remember that when biamping the 4345 with 24dB/oct, there is 360 degrees which is equal to zero... phase shift....whereas there is 180 degrees of phase shift with the internal 12dB/oct passive filter. When running the system in full passive the internal wiring color code takes care of the system's driver phasing...whether it be connected to the amp positive to black for the compression pulse first or positive to red for the rarefaction pulse first. It does sound different and feel different whether you get the compression or rarefaction first, and will also react to the room differently based on placement and room modes....but you already knew this;) .

[boputnam]

....but you already knew this;) .You bet! :D

But, it's not that simple. I've never run these passive. The factory active crossover - the 5234A which I used before this one - has -18dB slopes (but you already knew this... :o: ). So, I'm closer to the "factory" passive phase than your post suggests.


It does sound different and feel different whether you get the compression or rarefaction firstAlthough this we differ on, in home applications. Live (where it's my gear...), everything is AES convention (that is, pin2 (+), and woofs out on (+) ).

-----

Hell, I'm not even sure you can easily tell in many (most...?) live settings, either. There is so much interaction with the room, the ampitheater, the crowd, wind, walls, bleachers, whatever. Furthermore, with today's time-alignment in the system, and then the delay on the mains to "position" them with the Kit/backline, I just don't know. I know we'd all like to notice a difference - but will you, 10m, 20m, 30m out?

Someday I should soundcheck with the polarity normal and reversed, and test if we can really tell anything, honest A/B. There's never a great deal of time, but, someday...

[boputnam]

So, edgewound, maybe you're still watching? The question of live sound, brings a question:

You've probably worked on a great number of Fender amps. And, some have (D-, E- and) K-series woofs in-place of the original. How are they wired? Do you reverse their connections so they are cone out on (+)? That would be consistent with the kick and mic pulse. Just curious...

[edgewound]

So, edgewound, maybe you're still watching? The question of live sound, brings a question:

You've probably worked on a great number of Fender amps. And, some have (D-, E- and) K-series woofs in-place of the original. How are they wired? Do you reverse their connections so they are cone out on (+)? That would be consistent with the kick and mic pulse. Just curious...

Yes.

[boputnam]

Thought so.

I've not yet found one done that way - but I do suggest it to the artist. When they aren't I just switch the polarity on the mic input... :)

[Chas]

Hey, I've just had a fundraising idea for the LHS. Spend a day with your favourite LHS member....$500.00 donation:) . A day with Bo would be fun being his roadie....Is that the correct term?

Sorry, if this is off topic, but I think the polarity question is solved. By the way: I always get confused when people use the term phase instead of polarity. After all, you can have identical phase, but opposite polarity, right?:p

[edgewound]

Hey, I've just had a fundraising idea for the LHS. Spend a day with your favourite LHS member....$500.00 donation:) . A day with Bo would be fun being his roadie....Is that the correct term?

Sorry, if this is off topic, but I think the polarity question is solved. By the way: I always get confused when people use the term phase instead of polarity. After all, you can have identical phase, but opposite polarity, right?:p

Right...phase is concerning the time arrival of the drivers soundwaves and coherence with one another with regards to comb filtering, cancellations or good, accurate summation. Polarity just means how the wires are connected...which could turn into a loooong discussion on crossover design, physical alignment of the voice coils of each driver, cabinet design, etc....a blending of both art and science....kind of like a fine chef's creations...not everyone will agree on flavor;) :)

[B&KMan]

Hello with all, I arrive at the end of this other eternal problem of the polaity and the phase in the 4343... My experiment of the 2231 shows clearly that it has better an extension of the high frequencies if the impulse is negative (as prescribed by the manufacturer) of course, you can find that doubtful as method to stretch the band upwards but it is nevertheless the approach of JBL. thus if you to use the networks passive or credit of JBL and fact for this enclosure, you will definitively have a better integration by respecting the convention of connections of origin. However, your 2231 was certainly reconed, but the guy who did it by error "corrected the polarity" according to usual standards'??

manys other threads is builded on this question...

[B&KMan]

I wanted simply to add another information... The integration of the delay of the 2405 in the 4343 is bad it is necessary to put a delay of 0.613 ms approximately. If you use an active network which allow it, that could big improve realism of the sound...

:cheers:

[edgewound]

Investbikers 2231's weren't reconed...original voicecoils.


Really...this thread is all about the color of the terminals and getting the best bass response out of the woofers. JBL Literature states that the 4300 series monitors...and other models... have positive as the black input terminal. There is needless confusion here and intellectuallizing as to what JBL designed the polarity to be when the simple correct answer is the colors are reversed...and this goes back decades as to why it is that way. Some historians think that since electricians installed this stuff and Lansing was one of the first mfg's, black is hot on 120 volt AC...Maybe that's the right story, and I think Hal Cox told me that during a phone call about 16-17 years ago...and going forward starting a few years ago, JBL is going AES standard of RED=+.

But Geez...this has gotten way too deep...for the wrong reasons....the stuff is just backwards and a little digging on JBL Pro's website will enlighten. I've got an older version of the Tech Notes 1 Volume 12(12B is a revision that leaves out Lansing hisself) that explains it....I'll upload it when I have the time to scan it.

[boputnam]

But Geez.......the stuff is just backwards:yes: :rotfl:


I've got an older version of the Tech Notes 1 Volume 12 (12B is a revision that leaves out Lansing hisself) that explains it....I'll upload it when I have the time to scan it.Cool.
v12B has been posted here, a number of times.
v12C (June '05) is on the JBLPro website.
v12 would be the complete set.