PDA

View Full Version : Baffle layout



boputnam
08-31-2003, 10:05 AM
Anybody got issues with this proposed baffle lay-out?

Last night I got to thinking I should align the axes of the 075 and LE5-9, and mirror-image same-same in left cabinet.

Would I be better off trying to center/align the LE5-9 with the LE14A, and leave the 075 in the outer/upper corner for imaging?

:hmm:

Thanks!

(apologies for image quality - it was a very light pencil drawing on tracing grid paper...)

4313B
08-31-2003, 10:52 AM
"(apologies for image quality - it was a very light pencil drawing on tracing grid paper...)"

I'll send you over some bar napkins and a felt tipped pen.

"Would I be better off trying to center/align the LE5-9 with the LE14A"

No.

Try to get the LE14 at least an inch off axis as well. In other words, make sure no dimensions of the LE14 mounting hole are the same distance from any edge. e.g. The 240Ti has a nice baffle arrangement.

boputnam
08-31-2003, 11:02 AM
Thanks, dude! ;)

"make sure no dimensions of the LE14 mounting hole are the same distance from any edge" Got it. Glad I asked before cranking-up the plunge router... :bouncy:

Is the 240Ti ported out the back? Should I consider same? Pluses/Minuses...??? :confused:

Here's a close-up of the 240Ti, for completeness of the Thread:

4313B
08-31-2003, 11:17 AM
"Is the 240Ti ported out the back?"

Yes.

"Should I consider same?"

If you want.

"Pluses/Minuses...???"

I won't go there. :p Someone posted in another thread about mounting ports on backs of enclosures...

Earl K
08-31-2003, 11:25 AM
Hi Bo

I much prefer vertical axis alignments for my 2way MTM stuff .

I can't offer easy answers for your question for 3 way designs . You might want to try putting the centre of your mid on a line drawn between the tweeters centre of axis and the vertical "edge" of the le14a(s)' 4" dustcap - this of course builds in a slight offset ) .

I suggest an extra ( perhaps intrusive ) step that I feel every project should be going through. I do believe that the perennial DIYer should invest the time and energy into the crafting of at least 3 different sizes of paired test boxes. The sizes would be chosen to accomodate ones' most likely utilized component types. Removable baffle boards with different ports and speaker hole sizes - is an added option.

In your specific situation, a pair of small enclosures for the le5(s) would likely suffice - just sitting on the chosen woofer box - with a 075 perched on top of the mid box. I sometimes use "road-case" foam to create additional adhoc baffle boards ( between odd size components ) to investigate the effects of having ( or not ) continuous surfaces between components.

Once one has these test enclosures in place - then the DIYer can move the parts around like a jig-saw looking for a "best- match" between crossover slope-types and that specific crossovers' interaction with the real distances between drivers.

As a "for instance"; if one designed the crossover with pure 12 db butterworth slope, then one may discouver that adding a measured distance between components might mitigate some of the expected (? db ) summing bump. Finding a distance ( that offers the smoothest transition ) between components is best done in an empirical fashion - thus the project boxes . The smooth transition between components certainly seems to have been accomplished in the 43?? 4-ways. When looking at the distance between its components - it looks to me that spacings are quite calculated. So, "tight-packing" components isn't necessarily the "way to go" when using butterworth slopes. An LR slope would be my first choice when tight-packing (flange to flange) - as in my MTM setups .

regards <> Earl K

boputnam
08-31-2003, 11:25 AM
"Someone posted in another thread about mounting ports on backs of enclosures..." Yea, I remember that - thunderous rush of air sounds and all that. I don't know - I sure cannot hear a thing with the 4345's, and if front ports are noisy, I be staring at the butt-end of a 747-400!!

Only hesitation is, that Ti series has Greg Timbers all over it, and he's got more port knowledge than I! :thnkfast:

4313B
08-31-2003, 11:28 AM
"Only hesitation is, that Ti series has Greg Timbers all over it"

I know, I asked him when the Ti series first rolled off the assembly line "why is the port on the back?" I won't post the response :D

boputnam
08-31-2003, 11:34 AM
Hey, Earl K...

"You might want to try putting the centre of your mid on a line drawn between the tweeters centre of axis and the vertical "edge" of the le14a(s)' 4" dustcap - this of course builds in a slight offset." That was the "B" option I thought of, too. The Ti series effectively did just that in the 250Ti. And, it looks like even in the 240Ti the MF and HF are not exactly on-axis. Maybe I seek too much with too little.. :duck:


"I suggest an extra ( perhaps intrusive ) step that I feel every project should be going through. I do believe that the perennial DIYer should invest the time and energy into the crafting of at least 3 different sizes of paired test boxes." That, is almost possible - at least I can swap-in different baffle configurations. This project is based around a re-fit for the Altec ModelNine cabinets, so I cut-out the old baffle leaving a 0.75-in lip to secure the new baffle to. This gives me the chance to try googles of splendiferous :eek: configurations - if my plunge router holds out...

Thanks!

4313B
08-31-2003, 11:53 AM
"it looks like even in the 240Ti the MF and HF are not exactly on-axis."

They are on-axis, I have a pair.


We used to build quite a few custom 3-way systems using the 2235H, 2105H, and 2405 with the N65. They came out remarkably well. Better than hoped for.

boputnam
08-31-2003, 12:07 PM
"They are on-axis, I have a pair." Thanks.


"We used to build quite a few custom 3-way systems using the 2235H, 2105H, and 2405 with the N65. They came out remarkably well. Better than hoped for." Nice! Well, the benefit to starting with the 075 is, the baffle-cut is the same for the 2405's, a pristine pair which is also sitting on the bench! So, if the lads decide they can do without those great looking bullets, we can do the right thing... :yes:

Oh - and I too am a fan of your avatar (Guido beat me too it!). I was wondering what you might choose - quite fitting for the JBL techbot... ;)

4313B
08-31-2003, 12:23 PM
"Oh - and I too am a fan of your avatar (Guido beat me too it!). I was wondering what you might choose - quite fitting for the JBL techbot... "

Well thanks... it was either that or this

boputnam
08-31-2003, 12:37 PM
Er, ah, uhm, a WOW Baby!

I have always pictured you a man!

Please, oh please drop-by and enjoy my 4345's whenever you need... :bouncy:

Mr. Widget
08-31-2003, 12:39 PM
Hey Bo,

My only concern with your layout is that if your cabinet has a lip around the baffle as your sketch indicates there may be early reflection issues.

Just a thought...

Giskard, no comment.:)

4313B
08-31-2003, 12:59 PM
"I have always pictured you a man!"

Well, that's why I didn't use the pic as my avatar :no:
She is an avatar :yes: but not my avatar.

"Giskard, no comment."

k

boputnam
08-31-2003, 01:08 PM
Hey thanks, Widget!

The old cabinet did have a lip, but by adding the new baffle thickness on-top of the old, it's nearly flush (well, not flush by Widget standards, but close enough for an old cowboy... ;) )

But say, Widget - what do YOU look like, huh? :D

4313B
08-31-2003, 02:06 PM
"But say, Widget - what do YOU look like, huh?"

We already know what you look like Bo ;)

http://www.audioheritage.org/vbulletin/showthread.php?s=&postid=1025#post1025

I look a lot like this guy:

boputnam
08-31-2003, 02:08 PM
I WONDERED if you'd remember!

Yup, that's me. Then, and even more, now... :rotfl:

Mr. Widget
08-31-2003, 03:04 PM
Giskard, I hope you have better hygiene.:D

I'd prefer to think you resembled the bearer of the sword.

I almost scanned and posted a photo of Mr. Widget, but I really need to get back to the shop. I have some walnut calling.

I will post some photos tomorrow of some of my work.

4313B
08-31-2003, 03:11 PM
What does "hygiene" mean? :hmm:

"I'd prefer to think you resembled the bearer of the sword."

She does look pretty clean...

DavidF
08-31-2003, 11:19 PM
Say Bo, my first thought on the diagram is that there are a lot of holes in the baffle with the three drivers, the port, and the crossover panel. All this missing mass may cause some resonance issues on the front panel. This was my thinking on placing the port on the backside on my 3-way floor standing boxes. But, you may have to keep the port on the front if the required length requires a bend in the port. Installing on the back panel will probably run the tube into the woofer in some way. If you need to keep the port up front, a good stout back-side-front brace just above the woofer could be a benefit.

Regards,
David F

boputnam
09-01-2003, 12:52 AM
Hey, DavidF...

I'm following some old JBL plans, here, where a 3-ft3 cabinet for the LE14A calls for a 4" diam 3" duct. Looks kinda short to me, but the models I've run sez it's OK. That 4" diameter takes alot away from the needs of length. I'm willing and able to modify the port, if needed.

Here's relevant portion from the vintage plan:

Ian Mackenzie
09-01-2003, 03:55 AM
Regards the port pozzy,

Front baffle space reasons can be a benefit for certain layouts.

There are also noise (chuffing, organ pipe resonance and midrange output ) considerations. Port openings in the rear would have to be quieter, but the better way is to use bigger a port area to reduce air velocity and avoid the so called sonic boom effect according to some notable designers.

Although this in turn becomes even more impractical as larger ports demand even longer ports in boxes of limited size.

I read somewhere rear ports can also assist with modifying the bass output more effectively by moving the box in and out from the rear wall, presumable this is due to greater room gain from rear mounting if the port.

I recall rear ported bookshelf boxes have rather pronounced bass.

Some manufacturers are now offering adjustabe ports for modifying bass tunings to suit various rooms and locations.

Ian

4313B
09-01-2003, 12:38 PM
JBL Enclosure Information Manual.

http://www.lansingheritage.org/html/jbl/plans/1979-manual.htm

4313B
09-01-2003, 01:14 PM
Loudspeaker Enclosures Their Design and Use.

http://www.lansingheritage.org/html/altec/plans/1974-enc-manual.htm

4313B
09-01-2003, 01:52 PM
Originally posted by boputnam
Hey, DavidF...

I'm following some old JBL plans, here, where a 3-ft3 cabinet for the LE14A calls for a 4" diam 3" duct. Looks kinda short to me, but the models I've run sez it's OK. That 4" diameter takes alot away from the needs of length. I'm willing and able to modify the port, if needed.

Here's relevant portion from the vintage plan:

Hey Bo, I actually built a pair of these enclosures when I got my first pair of LE14A's!

I can't get all the actual plan sheets to scan. :( I was thinking of taking them to Kinko's. Anyway, I've attached the booklet that came with the plans above, as well as one for Altec. :)

boputnam
09-01-2003, 01:53 PM
Extraordinary effort, Giskard! And I think I have carpel tunnel syndrome!

I've had b/w copies of many, but now they're all compiled and buttoned-up within Acrobat, and look like they should! Ready for colour printing!

Very, very cool. :coolness:

What kinda mood you in!!?? A real Labor Day, my friend... ;)

boputnam
09-01-2003, 01:56 PM
"Hey Bo, I actually built a pair of these when I got my first pair of LE14A's!" Nice! I'll post some pics of the ending product. Only differences is I'm adding the LE5, and either the 075 or 2405, with the N65 network :eek: but that's all just for fun! :p

and


"I can't get all the actual plan sheets to scan. I was thinking of taking them to Kinko's." No need. I've already done them, and will try and follow your lead, here...

boputnam
09-02-2003, 04:18 PM
This evolved into a quite interesting, and archival thread! ;)

*****

In-between posts/steals yesterday, I redesigned the planned baffle that started this Thread, just a bit.

Reviewing all the literature and plans here and elsewhere, I came way with the (possibly unfounded...) impression that Bafflers tended to position the port near the LF. Not in corners or away from the LF, but near to it. I couldn't find anything actually written about this - and this is different then the front/rear argument (whoops! :smsex: ). Ha!

So, I elected to move the port closer to the LE14A - Option B, below. Any of our gang got experience with either - is there any preferred location for the port relative to the LF (staying on the front, for now... :D )

I have taken the advice and offset the LE14A from any symmetry with the baffle edges, too.

And, please, I already took the obligatory abuse for the poor image quality - I assure you the original is quite a different matter! :rotfl:

4313B
09-02-2003, 04:54 PM
"is there any preferred location for the port relative to the LF"

Generally you want the end of the duct that is inside the enclosure as far away from other internal surfaces as it practical. Option B in that respect would be preferred to Option A. Option A would be fine for a port such as that found in the 4313 or L96.

"I have taken the advice and offset the LE14A from any symmetry with the baffle edges, too."

Symmetry sure looks nice but it generally isn't a great idea in loudspeaker design.

4313B
09-02-2003, 04:56 PM
My attempt to scan in the 1977 and 1980 versions of this publication failed. I may take them to Kinko's in the future.

4313B
09-02-2003, 05:21 PM
In real life, this simply sounds better

4313B
09-02-2003, 05:21 PM
than this

boputnam
09-02-2003, 06:22 PM
With ports, thusly...?

DavidF
09-02-2003, 07:39 PM
Thanks, Giskard, for the effort to post these items. No doubt it took a fair amount of time. This is the type of material I enjoy that once fed the home-builder types that we do not see anymore (save a few that linger around these parts, me included).

Bo, your position on the port may be better, as mentioned, to keep it away from the internal surfaces. These can alter the air motion around the port, or so I read. You will note that the L110 for instance tucks the port way down in the corner. No doubt this is more of a design compromise. Canít get you to move the crossover to back side, huh?

David F

Mr. Widget
09-02-2003, 07:49 PM
Now this modification would get rid of all that excess baffle and allow the speakers to image more like one of those &$#@% audiophile speakers.:D

boputnam
09-02-2003, 08:07 PM
from DavidF
Canít get you to move the crossover to back side, huh? Well, the N65 network is on the rear, with the binding posts handily fit through an opening. But it's darn convenient to have the L-pad on the face. Plus, since it is a pristine L65 face-plate, it looks nice, too! :D

I take note of your concern on resonance, and need for bracing. But, this baffle is 3/4-in oak plywood, and much more stout than MDF. It feels very solid, but man, when all the transducers are mounted, that baffle weighs a tonne. The baffle will be secured to the 3/4-in lip remains of the original baffle with 8-32 machine screws and T-nuts, so things should be good.

Oh, btw, that suggestion of Sono Tube from Gordon W is tops. That stuff is very heavy duty, and makes an excellent mid-range subenclosure. After all is dried and such in the next week, I'll post some pics to "feed the home builder types - which is all of us, at least in spirit! :bouncy:

4313B
09-02-2003, 09:37 PM
"Thanks, Giskard, for the effort to post these items."

My pleasure. I hope everyone enjoys the postings.

"You will note that the L110 for instance tucks the port way down in the corner. No doubt this is more of a design compromise."

True. Like the L96 and 4313, the port/duct is bent 45 degrees and points up into the interior of the enclosure. I think that very same port is also used in the 4311 and 4312.

"Now this modification would get rid of all that excess baffle and allow the speakers to image more like one of those &$#@% audiophile speakers."

I was just trying to illustrate the point of mounting off-axis. The original L212 was very symmetrical. I didn't really want to change the actual physical dimensions of the L212 enclosure for the illustration.

"Oh, btw, that suggestion of Sono Tube from Gordon W is tops. That stuff is very heavy duty, and makes an excellent mid-range subenclosure."

Yes, I use them to make 112, 2108, 2122 and 2202 subenclosures. There are two places here in town that sell them. One will cut them up to any length I want and the other won't. You can probably guess which place I go to ;)

Mr. Widget
09-03-2003, 12:22 AM
Originally posted by Giskard
"Thanks, Giskard, for the effort to post these items."

My pleasure. I hope everyone enjoys the postings.

"Now this modification would get rid of all that excess baffle and allow the speakers to image more like one of those &$#@% audiophile speakers."

I was just trying to illustrate the point of mounting off-axis. The original L212 was very symmetrical. I didn't really want to change the actual physical dimensions of the L212 enclosure for the illustration.



Yes thank you very much. You have posted hours of fun reading on the site. Quite a Labor Day!

On the L212, I was poking at JBL and having a little fun drawing on your post.

Robh3606
09-03-2003, 06:22 PM
Hey Mr. Widget

You making fun of my XPL's:p

Mr. Widget
09-03-2003, 06:27 PM
Striking resemblance! How do they sound?

Robh3606
09-03-2003, 07:04 PM
They sound great! Really like that TI mid and they do image well. Would love to hear the real thing! I saw your sketch and well LOL I couldn't resist:D .

Rob:)

boputnam
09-03-2003, 07:39 PM
OK, Rob...

Now, give us the assemblage, piece-by-piece. We want to know all.

1. Transducers, by relative position and offset.

2. Then, go over the networks - active and passive

3. Then, the amps/EQ's, pre's...[/list=4]

Come on!

Mr. Widget
09-03-2003, 08:01 PM
Dang Bo, do you want his inseam too!:D

Alex Lancaster
09-03-2003, 08:29 PM
When using a comp driver in reverse, as pictured, what do You do with the horn exit?, make a plate to cover it, or add more volume?

Do You reverse the polarity?

Thanks.

boputnam
09-03-2003, 08:31 PM
Widget...

I'm guessing it's all here: Describe your HiFi System - Link (http://www.audioheritage.org/vbulletin/showthread.php?s=&threadid=147) but I was hoping for a but more detail to accompany the Zoomed view...

:D

and, Alex...

Those are great questions!!

Alex Lancaster
09-03-2003, 08:58 PM
Bo:

I went to the thread, but there is nothing in it that answers my questions.

Thanks: Alex.

Robh3606
09-03-2003, 09:09 PM
Hello Alex

That is not a compression driver reversed. Sure look's like one though. It is an 093Ti 3" titanium dome midrange driver JBL made in the 90's. There was an automotive version to the 030Ti. You see them on Ebay from time to time. Attach is a photo of the front panel of an XPL-140 speaker. It has the mid and 046 tweeter.

Rob:)

boputnam
11-17-2003, 10:49 AM
Originally posted by Giskard
We used to build quite a few custom 3-way systems using the 2235H, 2105H, and 2405 with the N65. They came out remarkably well. Better than hoped for. Hey, Giskard...

I got some very crusty L-pad's in these N65's I'm using. I dismantled and cleaned them all yesterday, but they still have dead-spots / intermittent. Do you know of a comparable L-pad that I might use / get from JBL Pro?

Nearly complete with the modified L65's:
075 (the lad opted for this over the 077)
LE5-8
LE14A

Already got the L-pads mounted, so I need to fit into these baffle holes.

I wondered if the L-pad in, say, the 4312 was similar to the L65 (save me from tearing into my 4312's L/R and have a look...).

Whadya think?

boputnam
11-17-2003, 11:03 AM
(talking to myself here... :nutz: )

Looking at the "N65 Variants schematics, the L-pad's there are numbered "10285". That's the same part number as for the 4312, as I had guessed.

Unless sombody stops me, I'm going in, boys... :rolleyes:

4313B
11-17-2003, 11:11 AM
10285's are junk!

At the very least use the 58450 L-Pad, if not the ceramic.


10285 L-Pad from Parts Express (http://www.partsexpress.com/pe/showdetl.cfm?&User_ID=16513260&St=8881&St2=69869716&St3=-70749323&DS_ID=3&Product_ID=5648&DID=7)

58450 L-Pad from Parts Express (http://www.partsexpress.com/pe/showdetl.cfm?&User_ID=16513260&St=8881&St2=69869716&St3=-70749323&DS_ID=3&Product_ID=5651&DID=7)

51594 L-Pad from Parts Express (8 ohm version - stock was 16 ohm) (http://www.partsexpress.com/pe/showdetl.cfm?&User_ID=16513260&St=8881&St2=69869716&St3=-70749323&DS_ID=3&Product_ID=5656&DID=7)

boputnam
11-17-2003, 11:16 AM
Nice...!

I'm thinkin' the 51594. Looks like it would fit right onto the original N65 L-pad foilcal setup.

Thanks, man. :thmbsup:

4313B
11-17-2003, 11:23 AM
Yep, just toss that goofy knob and plastic plate in the trash and then you have exactly what JBL would send you; except JBL charges a whole lot more and occasionally forgets to send the washers/nuts :D

boputnam
12-02-2003, 06:47 PM
Meet RH of the pair Modified L65.... Rob has been asking if he could see 'em.

Stereo-imaged pairs. The lad chose the 075's over the 2405 - he thought they looked "cooler". :coolness: I was OK with that, 'cause the 2405's now can go to the next project.

I'm hesitating completing the LH of the pair, thinking I might just baffle-around with a 128H and do some A/B comparisons. I'll let you know how it goes.

Oh, and grill-cloth (black :banghead: ) is in-hand, and will be fitted until we find the [i[right[/i] stuff!

Mr. Widget
12-02-2003, 06:59 PM
Nice work Bo! I agree with the lad, they do look cool!

Robh3606
12-02-2003, 07:08 PM
NICE!!

Thank's that looks great. That 2402 does look cool:D

Rob:)

boputnam
12-02-2003, 07:13 PM
The only oddity, is that JBL Blue with the white-faced LF. Not seen that before, but it sounds all-good.

Note the offset LF per Giskard's rants (ah, remember the day... :rotfl: ) but that positioning caused near endless iterations to avoid frame collision with the LE5-9 (due to the positioning of it's subenclosure to allow room for the 075). And then there's the 4-in port and 11.5-inch duct! I was going... :nutz:

Robh3606
12-02-2003, 09:32 PM
"The only oddity, is that JBL Blue with the white-faced LF. Not seen that before, but it sounds all-good."

Sure you have:hmm: Its perfect look at the legacy!

4350!

Earl K
12-03-2003, 05:51 AM
Nice Blue !

& a very handsome le14

<> Earl K:)

boputnam
12-03-2003, 08:45 AM
Thanks, Rob & Earl...

I forgot about them ol' 4350's - Yer right! And, those have the oddest mounting for the 2405's - seems the bracket is on front of the baffle. And, it looks like the bracket from a 2402!! :confused:

And, my photo doesn't do the JBL Blue justice. But, in-haste, it'll do until I get the duo completed.

boputnam
12-14-2003, 01:41 PM
...since they stick in my mind as being the main protagonists for building test boxes. Not exactly a test box, but with the donut on the left cabinet, I was able to trial a 128H in a baffle-cut fitted for the LE14A. The donut and 128H are airtight with dense (closed-cell) foam weather stripping. The duct is unpainted, since it was also customed for this trialing.

As of now, the LE14A "wins" in this A/B blind test.

boputnam
12-14-2003, 01:42 PM
Close-up

Ken Pachkowsky
12-14-2003, 02:08 PM
Curious to hear what they sound like?

Ken

boputnam
12-14-2003, 02:46 PM
Hey, Ken... :wave:

Well, they can't touch an L:):), but then again... :rotfl:

They are great - both iterations. The 128H (L) has a subtly more "filled-in" or full sound. The LE14A configuration (R) to me has more definition, and slightly stronger VLF (but the listening position a top that Teak stand-up workbench is not optimum - or is it...?). We did a blindfold test, and after different source materials the LE14A is coming-out modestly preferred, at least for this build.

NB: BBPro set Fb of 27.11 Hz (L) and 30.88 Hz (R).

4313B
12-14-2003, 03:38 PM
Those look quite nice Bo! :)

Yes, I realize they "ain't no L1:hyp::hyp:'s" but I'm sure they sound good anyway :p

L88P
12-14-2003, 04:16 PM
Very nice engineering Bo! :yes: Whatís the investment in material and labor hours in the cabinets? How does the 128H compare in the LF and MF range with an L112? Wonder what they would sound like with a 123A?

L88P
Roger

Guido
12-14-2003, 04:18 PM
They look perfect!

Nice baffle mod to enable the A/B Test:bouncy:

boputnam
12-14-2003, 06:01 PM
Originally posted by L88P
Whatís the investment in material and labor hours in the cabinets? How does the 128H compare in the LF and MF range with an L112? Wonder what they would sound like with a 123A?
Well, as I (think...) posted much earlier-on, the cabinets are some old Altec Model Nine's that I re-employed, here - they had just about the minimum volume to try the LE14A's. The 128H is the LF in the L112 (right...?), so that's an easy comp. :yes: I prefer the 128H over all the JBL 12's. I even swapped 'em into my 4312's a while back and was very pleased with the improvement (and I otherwise am not a fan of swapping-in different JBL components. "Just won't work" :scold:...).

I have A/B'd the 123A vs the 2213H, the 123A vs 128H, and 128H vs 2213H, and the 128H wins. And yes, I maintained proper polarity - that's how I got into that whole mess in the first place! ;)

L88P
12-14-2003, 08:53 PM
Originally posted by boputnam
Well, as I (think...) posted much earlier-on, the cabinets are some old Altec Model Nine's that I re-employed.

I missed that... I was thinking maybe this was going to be a limited production line, maybe the B43xx something similar.

, here - they had just about the minimum volume to try the LE14A's. The 128H is the LF in the L112 (right...?), so that's an easy comp. :yes: I prefer the 128H over all the JBL 12's. I even swapped 'em into my 4312's a while back and was very pleased with the improvement (and I otherwise am not a fan of swapping-in different JBL components. "Just won't work" :scold:...).

I have A/B'd the 123A vs the 2213H, the 123A vs 128H, and 128H vs 2213H, and the 128H wins. And yes, I maintained proper polarity - that's how I got into that whole mess in the first place! ;)


I missed that... I thought this could be a limited "Bo" production run.

I was asking if you could comment on the performance differences from the 128H in the 112 vs your design?

For a 12' the 128H is nice... I've got a pair in 112's, gifted to my oldest son! I hear them through the walls, that's my first clue he's home on college break :wave: not an Alnico correct?

I'd like to test LE5-2's in pair of 166A's... anything to look out for here?

Why the 128H over the 123A?

JBL should have took a tip from GM and the SBC on the polarity... keep it the same. With the 43XX components, is the polarity all :spin: also?


L88P

Roger

boputnam
12-14-2003, 09:54 PM
Hey, Roger...

Whoa - lotsa stuff there, pard'.

I can't comment upon the differences with this, and the L112. I'm using the N65 network, so for starters that is a bit different.

I love the comment about the son - my daughter "enjoys" her L26's same-same... ;)

I MUCH prefer the performance of the 128H. Significant design improvements over the 123A, IMO. Quite audible. :yes: Try some modelling in WinISD or BBPRo, for same cabinet sizes, and you'll grok the situation.

No, there is nothing "different" about the 43xx series component polarity. It's all JBL, and consistently negative (at least at the component level - ex-network polarity is another thing entirely...)

Ian Mackenzie
12-14-2003, 10:20 PM
Why not put L100 emblems on them Bo, t'll makem sound better!!


Ian
:rotfl:

boputnam
12-14-2003, 10:48 PM
:banghead: