JBL 4401s [Archive] - Lansing Heritage Forums

alexkerhead

10-31-2006, 10:30 AM

I got them in yesterday and have given them a good listen on 10 different receivers.
Receivers/amps used:
SX-1250
SX-680
Marantz 2265B
Marantz 2270
Marantz 1530
Marantz 2220B
Marantz 2216B
Realistic ST-500 integrated
Sherwood 7100A
Magnavox 6V6 tube amplifier

I must say, for their size, they are amazing. Best sounding 6.5" midbass I have heard and the tweeters are incredibly detailed compared to what I am used to with the LE25s in my L100s.

They sounded best on the Marantz 2265B, Pioneer SX-680, and the Pioneer sx-1250.

Excellent speakers all around. I have added them to the top of my L100 stack to compensate for the L100's rolled off highs.
Definetely whomped my L100s in HF detailing, heard some stuff I cannot hear on my L100s.

Just an opinion from an audio newb here.:)

Zilch

10-31-2006, 01:01 PM

soundboy

10-31-2006, 01:27 PM

Get some 4406's. I have had both. The 4406's are more extended top and bottom, and way more transparent. The 4406's I still have also have mylar caps bypassed with polyprope from the factory...the 4401's I had were equipped with electrolytics everywhere, even though they were older production:blink:....regardless, the 4406's just sound quite a bit smoother and detailed....and they are still cheap....I got a mint pair for $180.00 including shipping. I have seen them go for substantially less, but they aren't all that common on ebay anymore...I would keep both, though, if you can...the 4401's do have a noticeably punchier bass, because of the stiff paper/aquaplas cone. They also both look pretty cool in their own ways...one of the reasons I was always a sucker for JBL stuff....JBL got you all excited reading the color brochures for everything they made....they have to show you pics of the raw cast machined drivers, response graph's, etc....and then you have to have it....Rock on!

alexkerhead

10-31-2006, 04:14 PM

AHHHH, the light goes ON!

:hmm: Consider this:

http://audioheritage.org/vbulletin/showthread.php?t=11756

Can you mod 035tiAs (cheap on eBay, or maybe someone here has a pair for you to try,) to fit your DIY in-line L100 driver alignment? They play to some outrageously high frequency (27 kHz?) as I recall.

That's a far better approach than trying to boost the paper tweeters with EQ.

Also, as we've discussed before, getting down to just ONE tweeter and mid playing per side will be a substantial improvement.

Maybe try this with your 4401s:

Run a pair of your L100 woofers ONLY as "subs" with them. Make sure you get the phase correct.

Then, having stated elsewhere here that you don't like boomy bass, close the ports on the L100s with plumbers' test plugs (from the hardware store), and see if you don't like this combination even better with the boomy bass gone.

If so, add a sub crossover on the system to shut the woofers down above ~100 Hz.

THEN, you'll have a stack that actually works. (See below)

A waste of L100s using them just as subs? Find a pair of L88 cabs like these to refurbish. Same box, basically, with cool Eames moderne grilles to match your '50s phones.

[Pull the port plugs any time you want the boomy bass back.... :bouncy: ]
Thanks zilch, I did see your thread on modifying L100s. Awesome info.

I will keep an eye out for some lancers, but they don't seem to come up on fleabay that often.:(

Seems the light did come on, I was missing a lot of sound in the higher frequencies, especially the 11KHz+.
But my modded(bastardized) L100s will make great experiment fodder!
And if I can follow your steps correctly, it should turn out nicely.
I will attempt to copy what you have done in the image you posted!

Soundboy, I will keep an eye out for some 4406s, but likelyhood of finding them is low if they aren't often put on fleabay.

Alabama sucks for trying to find good speakers, most idiots down here buy sansui kabuki because they are flashy(Alabamians aren't to bright most of the time)(my mother comes from minnesota, so I got lucky not to be entrenched with redneck DNA)
So yeah, all you see for sale down here is kabuki and realistic speakers.
The occasional audiophile(rare) might have some nice stuff, but not many audiophiles in Alabama either.
I got my original L100s from my older brother, who got them from my dad, and he used them with a pair of L65s back in the 70s audio haydays.

Enough:blah:

Zilch

10-31-2006, 05:21 PM

I will keep an eye out for some lancers, but they don't seem to come up on fleabay that often.:(Two pair of L88 Nova grilles sold on eBay in the last couple of months; there musta been cabs what went with them. (I snagged one of the grille pairs, actually.)

They seem to get parted out more often than sold complete. There's a set of crossovers listed right now, for example. The chop shops don't want to mess with selling the cabinets on eBay, but for every L88 crossover or tweeter listed, there's a cabinet and grille ripe for refurbishing. Watch for the parts to be listed and contact the sellers regarding the cabinets. My mint-condition grilles came from Georgia, as I recall.

Here's a link to a recent post re: Eames speakers. Click the links there to see the similar JBL L88 Novas:

http://audioheritage.org/vbulletin/showpost.php?p=124748&postcount=7

They preceded L100 by several years, and, though merely a two-way, I find them to be a better-sounding (not to mention better LOOKING) speaker. 035tiAs in THEM would be a worthy upgrade as well.

XO was 2 kHz, 12dB/octave:

http://manuals.harman.com/JBL/HOM/Technical%20Sheet/L88%20Nova%20ts.pdf

4408 crossed 035tiA at 2.5 kHz. I don't know how low it can be used successfully; someone here with the data sheet might look it up and post the minimum recommended XO frequency and slope.

Just to be clear, I'm recommending you try them merely as subs with your 4401s, but they're also neato-looking two-ways, if that doesn't work for you.

[I've already posted how to make them "killer" in DIY, and it ain't by adding LE5-2.... ;) ]

SEAWOLF97

10-31-2006, 07:38 PM

the tweeters are incredibly detailed compared to what I am used to with the LE25s in my L100s.Definitely whomped my L100s in HF detailing, heard some stuff I cannot hear on my L100s.

Alex..I think you are starting to catch on to the current role of L100's . They get your foot into "the JBL door". After a while , you outgrow them and find other models that have more to offer.

Amazing how many members have the same story
" started out with L100s, eventually upgraded, passed L100s to son who loves them, then HE outgrows them, then the cycle repeats....."

alexkerhead

10-31-2006, 08:04 PM

I understand now seawolf97, indeed they did get me in the door.

I plugged the L100 ports on one set, tunred off the other set and disconnected the mids and tweeter in the set of L100s with the plugged ports.
Zilch was right, this is a better configuration!
Sound similar to a set of L-112s if my memory serves me well. Bass leaves a bit to be desired, but I might just build some large 3cu.ft cabs for the woofers by themselves.

Thanks zilch!

Zilch

10-31-2006, 08:34 PM

Bass leaves a bit to be desired, but I might just build some large 3cu.ft cabs for the woofers by themselves.

Thanks zilch!No problem, Alex.

Johnaec's cutting me a pair of new baffles for my C36 Viscounts (3 cuft.) to try the same thing.

123A(-x)/2213H is a closed-box driver with deliciously low free-air resonance. I'm anxious to hear what they can REALLY sound like! :thmbsup:

alexkerhead

10-31-2006, 09:29 PM

No problem, Alex.

Johnaec's cutting me a pair of new baffles for my C36 Viscounts (3 cuft.) to try the same thing.

123A(-x)/2213H is a closed-box driver with deliciously low free-air resonance. I'm anxious to hear what they can REALLY sound like! :thmbsup: Interesting.
Looks like we shall both find out how they sound!
Mine won't look very good, I am a poor wood worker!
But I can try and make them not look like crap.
My stupid ass made a set of cabs once from pine, that was the dumbest thing ever, they didn't even sit flat.:blink:
I am thinking old school 50s style cabinets, ya know square front, not too deep.:)
I may even try some glass on top with a viewing area to see the woofer, but that will be hard to keep from having air leaks...squeak squeak.:D

I also have 2327 horns, I just need to find some compression drivers for them.

Zilch

10-31-2006, 09:58 PM

Mine won't look very good, I am a poor wood worker!
But I can try and make them not look like crap.The single most important thing about closed boxes is that they really be well sealed. Carefully caulk all of the joints from the inside once completed, and use closed-cell foam weatherstrip (1/2" x 1/8" from Ace hardware, for example) as a gasket behind the woofer flange....

Edit: Here's my "vintage" cabs I'm using for this:

http://audioheritage.org/vbulletin/showthread.php?p=126539#post126539

That's an interesting thread on this subject, if you haven't read it before. Design graphs are in Post #25.... :thmbsup:

http://audioheritage.org/vbulletin/showthread.php?p=126647#post126647

alexkerhead

10-31-2006, 10:15 PM

The single most important thing about closed boxes is that they really be well sealed. Carefully caulk all of the joints from the inside once completed, and use closed-cell foam weatherstrip (1/2" x 1/8" from Ace hardware, for example) as a gasket behind the woofer flange....

Thanks for the suggestions!
I will try and get some birch for this project.:)
And a fuse for my table saw.

Zilch

11-01-2006, 01:29 AM

Yup, 3/4" birch ply with bracing should be good enough for this small of boxes. :yes:

[They be "Experimental".... :D ]

If they work, the finishing touch is here:

http://audioheritage.org/vbulletin/showthread.php?t=3216

alexkerhead

11-01-2006, 02:05 AM

I think since I am going to spend all that money on plywood, maybe I need to build something with some flexibility.

I was thinking 28"tall, 28"wide, and 14"deep internally.
Externally, it should be 29.5"tall, 28"wide, and 15.5"deep.
With overhanging top and bottom peices.

Roughly 6.35 Cubic Feet

What do you think zilch?
here is a drawing of the design I did in paint.
Imagine appropriate cross bracing as well to reduce resonance.

What compression driver for the 2327s would you recommend?

Thanks again for all the help!

Zilch

11-01-2006, 02:28 AM

You need to go back and read this thread again:

http://audioheritage.org/vbulletin/showthread.php?p=126371#post126371

The box you propose is way too large. Even at 5.0 cuft., you're out of cone excursion at 35 Hz.

I chose 3 cuft. because air cushion inside the box keeps 123A-x "safe" all the way down at 50W rated power.

Did you feel what happened to the cone when you plugged the L100 port? It goes from floppy to stiff instantly. Quite amazing what a closed box will do to damp the cone movement.

Exterior dimensions of my 3.0 cuft. boxes are 19-3/8"W x 23-3/4" H x 15-7/8" D. The front baffle is recessed 1-1/2".

2327 is a throat adapter, not a horn. If you want to do compression driver/horn, I'll have some inexpensive recommendations for you in that area.

That's a WHOLE 'nother subject....

alexkerhead

11-01-2006, 02:44 AM

You need to go back and read this thread again:

http://audioheritage.org/vbulletin/showthread.php?p=126371#post126371

The box you propose is way too large. Even at 5.0 cuft., you're out of cone excursion at 35 Hz.

I chose 3 cuft. because air cushion inside the box keeps 123A-x "safe" all the way down at 50W rated power.

Did you feel what happened to the cone when you plugged the L100 port? It goes from floppy to stiff instantly. Quite amazing what a closed box will do to damp the cone movement.

Exterior dimensions of my 3.0 cuft. boxes are 19-3/8"W x 23-3/4" H x 15-7/8" D. The front baffle is recessed 1-1/2".

Link me to some info on your horn. I'm drawing a blank on it....
Ah, I didn't realize that.
I guess 3cu. will be fine, I wanted a larger cab(to emulate old school speakers), but I dont want to sacrafice SQ.
I like your dimensions however.

Here is an image of the small horns.

Zilch

11-01-2006, 02:50 AM

Yeah, those be 1" to 2" throat adapters, not horns....

alexkerhead

11-01-2006, 02:52 AM

Yeah, those be 1" to 2" throat adapters, not horns....
So, they are like totally useless for my project?:(

Zilch

11-01-2006, 02:54 AM

Well, useless as horns, yes.

Not to worry. You can get into EXCELLENT JBL horns for $10 apiece. :D

Trust the Zilchster on this one:

http://audioheritage.org/vbulletin/showthread.php?p=123070#post123070

Draw the cabinet around that woofer and horn in your mind.

The horn is 12" W x 6.5" H....

alexkerhead

11-01-2006, 03:13 AM

Where do I get me some?:)
Like this?

Zilch

11-01-2006, 03:25 AM

Yes. You've got the idea, now. Scoot the woofer up closer to the horn, maybe 3/4" between them as in my photo, and then both of them up toward the top of the box a bit. The woofer will be playing midrange; for floorstanding, the drivers should be biased toward the top. Legs are gonna help some with that part, if used.

Send me a PM if you want me to order you a pair of the horns.

Refine the dimensions of a design for a 3 cuft. internal volume box incorporating that horn and the L100 woofer according to your desires.

$20 is not a huge investment to have them in hand, but I don't think you should further invest in compression drivers or crossovers until we both complete the boxes and see if you like how they work with the woofers.

The compression drivers I will recommend will be ~$125 apiece, and the crossovers, I don't know yet....

I've gotta go now and send Johnaec the final dimensions for my baffles....

alexkerhead

11-01-2006, 03:27 AM

Yes. You've got the idea, now.

Send me a PM if you want me to order you a pair of the horns.

Refine the dimensions of a design for a 3 cuft. box incorporating that horn and the L100 woofer according to your desires.

$20 is not a huge investment to have them in hand, but I don't think you should further invest in compression drivers and crossovers until we both complete the boxes and see if you like how they work with the woofers.

The compression drivers I will recommend will be ~$125 apiece, and the crossovers, I don't know yet....
Looks like I found something to spend holiday cash on(compression drivers)
I will send you a PM.
Thanks a ton zilch!

Zilch

11-01-2006, 01:38 PM

I wanted a larger cab(to emulate old school speakers)....
Our cabinets are decidedly "Old School." :p

Here they are in the 1952 catalog:

http://www.lansingheritage.org/images/jbl/catalogs/1952/page1.jpg

Check out the dimensions there.

[Looks like their size stayed the same for 54 years.... :applaud:]

alexkerhead

11-01-2006, 02:40 PM

Our cabinets are decidedly "Old School." :p

Here they are in the 1952 catalog:

http://www.lansingheritage.org/images/jbl/catalogs/1952/page1.jpg

Check out the dimensions there.

[Looks like their size stayed the same for 54 years.... :applaud:]

:D
Add some peg legs and it becomes 60s style.:bouncy:

Zilch

11-01-2006, 03:12 PM

alexkerhead

11-01-2006, 03:21 PM

The dimensioned plans are in the LH Library, actually, including the '50s legs:

http://www.lansingheritage.org/html/jbl/plans/c35-c39.htm

http://www.lansingheritage.org/images/jbl/plans/c35-c39/page2.jpg

The front moulding on mine uses a 3/4" inch strip rather than the 1/2" shown there, for a "bolder" look.

Our baffles are different, of course.... :thmbsup: Thanks for the reference!

I am going to model mine off the model 38 Lo Boy design. I know the wider approach make driver mirroring mroe difficult, but come on, that model 38 looks really nice.:)

Now I need to make plans!

Mr. Widget

11-01-2006, 03:46 PM

I got them in yesterday and have given them a good listen on 10 different receivers....Back to the original subject of this thread... was there a significant difference between the various Pioneer, Marantz etc. receivers? I have never bothered to compare more than one or two, but I always felt that most of the '70s era Japanese receivers sounded pretty much the same. At this point in history, some or most of the differences you heard could be due to bias drift and other time related issues.

A decent amp and preamp will usually sound significantly better... the more revealing the speakers, the greater the improvement.

Definetely whomped my L100s in HF detailing, heard some stuff I cannot hear on my L100s.That tweeter in the L100 isn't particularly stellar, so that is no surprise.

Widget

alexkerhead

11-01-2006, 03:51 PM

Back to the original subject of this thread... was there a significant difference between the various Pioneer, Marantz etc. receivers? I have never bothered to compare more than one or two, but I always felt that most of the '70s era Japanese receivers sounded pretty much the same. At this point in history, some or most of the differences you heard could be due to bias drift and other time related issues.

A decent amp and preamp will usually sound significantly better... the more revealing the speakers, the greater the improvement.
That tweeter in the L100 isn't particularly stellar, so that is no surprise.

Widget
I adjusted the DC offset and bias for all the units and the over 30wpc receivers I recapped.
Pioneers have great high frequency articulation.
Marantz is very warm, makes you feel comfy when you listen.
Sherwood sounds almost like a tube amp.

Each receiver's pre amp and amplification sections reproduce the sound quite differently.

If you get a chance, try it out, old receivers have a very old-timey sound new stuff cannot offer, which makes the older speakers I use sound more like they were intended.

The speakers Zilch is helping me with will most likely be powered by a 40wpc tube amp I am working on.

Zilch

11-01-2006, 04:01 PM

Member John W made a beautiful "Mini" version of that one recently:

http://audioheritage.org/vbulletin/showthread.php?t=12545

I'd be makin' the horizontal version, too, BUT there's other critical design considerations, most importantly related to using a horn:

1) Most rectangular horns intentionally have wider dispersion patterns for the horizontal than the vertical. The $10 JBL one we're using is 90° H x 50° V, as example. You don't want the wider dispersion to be the vertical; the horizontal will be "beamy," and will not match the dispersion of the woofer. This matters.

2) There ARE rectangular horns by other manufacturers with patterns suitable for vertical mounting, typically used in stage monitors. They're more like $100 apiece, tho, and do not have the excellent performance of the Progressive Transition waveguide we're using. It was developed using finite element analysis. We don't want to abandon it. Here's the white paper:

http://www.jblpro.com/ae/pdf/PT_WaveGuide.pdf

3) Ideally, the axis of the HF driver should be at listening height, with the others proximal for a coherent blend of sources. The vertical configurations gets us closer to that, whereas the "Lowboy" configuration sets it too low, even if a symmetrical dispersion (round, for example) horn is used. Thus, it's only suited to elevated mounting as a bookshelf speaker, unless an asymmetric horn is used to "aim" the axis upward. Those are available, yes, but once again, significantly more expensive. Another option is a symmetrical horn on a tilted baffle, but there's other compromises with that approach, as well.

There are compromises in all of this, but remember that the bottom-line objective is for the system to sound its best, and the factors I have outlined above are just as significant, if not more so, as the earlier choice between 6.35 and 3.0 cuft of cabinet volume.

Appreciate that designing a system such as this is MUCH more than throwing drivers and a horn in a box if the result is going to sound good....

alexkerhead

11-01-2006, 05:09 PM

I understand.
I will modify my plans I have made, really all I have todo is flip the boxes 90 degrees and it will be correct.

alexkerhead

11-01-2006, 05:17 PM

Here is the rough drawing of what I had in mind for a vertical speaker.

Zilch

11-01-2006, 05:27 PM

That looks good.

I think I'd move the woofer up a bit closer to the horn. You want about 3/4" between them. The top of the horn should be 1" - 1.5" down from the bottom edge of your moulding.

Moving the woofer up a bit will also allow more room at the bottom corners for a pair of ports if you want/need to add them later for a different woofer.

[With ported 2206H, these'd make kick-ass party speakers.... :D ]

alexkerhead

11-01-2006, 05:31 PM

Thanks zilch.
Here it is modified with the drivers closer together.

Zilch

11-01-2006, 05:39 PM

Better, but maybe too close together now. :p

Your horn proportions look wrong. 12" x 6.5"

I measure woofer outside diameter as 12.1875"

Baffle cutout is 11.0625"

Check those diameters before cutting, tho.

The drawing's not precise, I recognize. You know the layout parameters now.... :thmbsup:

alexkerhead

11-01-2006, 05:42 PM

Better, but maybe too close together now. :p

The drawing's not precise, I recognize. You know the layout parameters now.... :thmbsup:
Tommorrow I will draw by hand the correct inch scale model on paper and figure out how much wood I am going to need.

So far this has been a lot of fun, and I think the fun will increase once I get in the shop and start building these things.
My table saw is burned up, so I will have to cut them elsewhere, so accuracy in cutting is a must.
I think 2x 4'x8' sheets of birch should do it.

Zilch

11-03-2006, 12:29 PM

1, 2) Not a lotta room on my baffles, but they'll fit nicely.

3) Widget's 12" dogbone-horn monitors.

Mr. Widget

11-03-2006, 12:36 PM

Zilch, those dog bones are from Meyer Sound... they are a 1.5" modified radial horn... you might grab one and give it a try in your 1.5" trials. I believe they are around $125 ea. from Meyer.

Widget

Zilch

11-03-2006, 01:05 PM

I can't see Widget's pic on my monitor, so I brightened it up for those in the same circumstance.

What does this have to do with 4401s?

Me and Alex are doing a top-secret transcontinental undercover DIY incognito here. If it's a total bust, all posts not directly relating to 4401s will self-destruct, and we will disavow any knowledge of this project! :D

[NOW, he's gonna want Sub1500s to go WITH! Just need to stack those, Mr. Widget, and you'll maybe HAVE something there.... ;) ]

Mr. Widget

11-03-2006, 01:10 PM

On my monitor it is seriously washed out now... the original is dark to be sure... a black speaker against a navy blue curtain and all... but I think your monitor is out of calibration, or perhaps you are in a very bright room.

Widget

alexkerhead

11-04-2006, 12:40 AM

Yes, zilch and I are trying to achieve greatness with little money.:)

I went and looked at some cabinet quality birch today and home depot has it in stock.
$39.99/sheet(4'x8')
They will even make all the cuts I want for free..:blink:
I wont be able to start until tuesday, but I think this will be a fun project.

Zilch

11-04-2006, 01:37 PM

I've got two viable crossover options working so far, one of them "quasi-three-way." That means separate MF and HF adjustments with the single HF driver.

Using L40s as a test platform right now:

http://audioheritage.org/vbulletin/showthread.php?p=132152#post132152

Johnaec's finishing up my baffles today, so I may be able to do some measurements on the complete system soon.

BB6P says we'll get 8 Hz more (lower) usable bass extension (orchid) than these already fine L40s are producing (black). :thmbsup:

alexkerhead

11-04-2006, 04:03 PM

:eek:

That is some ridiculously low bass response!

I hate to ask, but what are the capacitor and resistor values for the crossover?

I will need to order caps and resistors if necessary.

Zilch

11-04-2006, 11:09 PM

Throbbing quarterpanel megabass, actually. :p

Getting everything sealed was kinda labor intensive. Used lots of closed-cell neoprene weather strip to seal the baffle, back, and drivers. Horn was the toughest; back side of the flange is not solid.

I'll load the second one and get measurements tomorrow. Gotta get it up off the floor for that.

I did confirm Fc of 41 Hz, exactly what BB6P says it should be, just to be sure I got it sealed well.

The curve above is simulated with no crossover. It'll play like that as sub for your 4401s until we get everything else worked out.

That rat's nest on top is one of the crossovers I'm trying with it.

Thank you, Johnaec!! Beautiful job on the perfect-fit baffles. :thmbsup:

[Gonna make you start signing this stuff..... ;) ]

macaroonie

11-05-2006, 05:01 AM

Try using a non setting ' Frame Sealant ' for those awkward jobs like the horn flange. Comes in a squirty tube but is NOT silicone and is NOT caulk. Most builders merchants should carry it. Turpentine for cleanup.

alexkerhead

11-05-2006, 11:34 AM

I cannot wait to get started on mine!

johnaec

11-05-2006, 05:55 PM

They look good, Zilch!

I think the codeine I was taking for my back pain when I was over filtered my hearing too much to comment reliably on your other systems using the 2452 drivers when I was over - I'll have to give another listen again sometime...

John

Zilch

11-05-2006, 07:00 PM

1) After thoroughtly sealing all joints, "shoulders" for installation of front and rear baffles get self-adhesive closed-cell neoprene foam weatherstrip. View from rear.

2) Baffle with T-nuts is installed using #6 x 1-5/8" deck screws, angled slightly outward.

3) Weatherstrip seals installed on the front for horn and woofer.

4) Drivers installed.

Zilch

11-05-2006, 07:01 PM

5) Drivers and horn from inside. Yes, the box needs bracing. Haven't figured that out yet; want to be able to remove the baffle.

6) Design calls for "heavy" fill. Around here, that means high-density R-21.

7) STEREO!!

[Pop quiz - which model are the woofers? :) ]

Zilch

11-05-2006, 11:11 PM

Performance measurements here:

http://audioheritage.org/vbulletin/showthread.php?p=132587#post132587

:D

Zilch

11-06-2006, 03:09 AM

O.K., first listening impressions with Dzihan & Kamien, Patricia Barber, Larry & Lee, Keith Urban, Little Feet; 85 to 90 dB at listening position:

These have a unique, very pleasant voice. The bass is really big, with full tonality, perhaps a bit TOO big; I may try to knock that down some. In any case, it's different from, and I'd say better than, what a typical ported enclosure would provide. We've discussed the rationale for this over in the Acoustic Suspension thread.

The mylar diaphragm re-entrant ring radiator high frequency compression driver is smooth and mellow, playing out to 20 kHz. (See the performance measurements.) After hearing the damped titanium of 2452H-SL for nearly a month now, it's tough for me to listen to plain titanium diaphragms anymore. I've always liked these mylars, and of course, aluminum with its inherent damping.

The $10 PT Waveguide delivers. I'm crossed at 1.2 kHz with 3120A, and that's no sweat for either it or the HF driver. Pattern control is excellent, so tight I gotta be sitting down at 7' since the horn axis is only 24" off the floor in these. If 123A-x can't play well that high, I'm not sensing it.

These are shallow-frame woofers, physically, and the HF driver uses a thread-on throat adapter, adding depth to it. CLIO says I can achieve optimum time alignment for this woofer/HF driver/horn combination by rear-mounting the 123s. Having the removable back panel on the cabinets will allow me to try that.

I'd call these a success, and I'm anxious to hear what other listeners will have to say about them.

[May have to order up some stilettos... :thmbsup: ]

johnaec

11-06-2006, 06:06 AM

Nice work, Zilch! The 3120A has CD compensation built-in, right?

John

clmrt

11-06-2006, 06:40 AM

Z -

Do you have a day job??:blink:

alexkerhead

11-06-2006, 06:43 AM

Wow, nice!
I cant wait to start on mine.

Still gotta find some money for some birch. I almost cheaped out and got pine, but I decided to wait for the right stuff.
Plus it gave me a chance to see your impressions.

Is that a 2213 woofer out of a 4311?
Seems like the same basket, but motor assembly is smaller.

Zilch

11-06-2006, 11:58 AM

Nice work, Zilch! The 3120A has CD compensation built-in, right?Yup, with several different selectable slopes, depending upon three settings each, mid and HF boost. I haven't dug into designing a specific crossover for them yet; just trying whatever might at least play them here. The additional L-pad is necessary for these very efficient HF drivers, and gives even more adjustability for balancing with the woofers. New system, I usually grab 31xx to tell me "where I'm at."

Z - Do you have a day job??:blink:It was the weekend. (And very, very, late night listening.... ;))

Is that a 2213 woofer out of a 4311?
Seems like the same basket, but motor assembly is smaller.Good guess, Alex, but it's actually the basket that's different. The motors are the same. The clue is on the front. Edgewound earlier documented this difference in the drivers for us:

The 123A-1 on the left has the terminals and voice coil leads midway between the frame webs, and thus between the mounting holes, so you can see the leads oriented at 12:00. See post #35, second image for rear view of that driver.

On the 123A-3 on the right, the leads are aligned with the frame web and mounting holes, instead, and thus you see them at 10:30 where I've oriented this driver. See top pic in post #47 - terminals are mounted on the web itself.

Also, 123A-1 is positive polarity, and 123A-3 (2213) is JBL standard negative polarity convention. You'd know THAT soon's you hooked these up:

"HEY, where's all the BASS these're s'posed to have? :banghead: "

alexkerhead

11-06-2006, 02:14 PM

On AudioKarma, someone recommended a 4"x4" flared port on a 123A-1 in the stock box.
Maybe something similar would work?

Just a thought.

clmrt

11-06-2006, 02:33 PM

"Stock Box"

?

4401 box?:D

123A, 3 cu ft, 4x4 vent and closed =

Zilch

11-06-2006, 02:34 PM

Run the sims in WinISD, BB6P, or any box design program.

Show us ANY port configuration that will "fix" the bass in that too-small stock L100 box short of closing it as I have documented in these forums.

Not gonna happen, I don't believe. It's a closed-box woofer, according to the T/S parameters....

*****

AudioKarma - isn't that where they suggest that woofers need to be at the bottom of a cabinet because bass is heavier than treble and will interfere with it as gravity pulls the bass down?

[Where is that post again, now? I can find the one where virtual performers are taller with stacked L100s, but not that one.... :p ]

*****

EDIT: Thanks, clmrt! There's our closed-box C36s on a different simulator - Woo HOO!! :bouncy:

[I'm NOT making the this up AFTER all.... ;) ]

alexkerhead

11-06-2006, 03:50 PM

His simulation suggests the bass is better than stock L100s, which is excellent, but you were complaining about lack of bass zilch?

Stock l100s are bassy enough..:blink:

Edit: I mixed them up, I see the problem now.
Less bass is a pay off for a better curve.
I downloaded winisd and will mess with it tonight.

Zilch

11-06-2006, 04:25 PM

... but you were complaining about lack of bass zilch?Not hardly. The standard complaint about L100 bass is that there is too much, and it is "boomy." Sims and measurements confirm that. I can't imagine anyone but a "Beater" wanting more than what they deliver, standard. Like you say, they're "bassy enough," and as you correctly observe, the objective of my L100 "fixes" with respect to the bass is to strip away the boominess.

Closing the port accomplishes that, as you'll see in WinISD. The perceived result is loss of bass, but the REAL result according to the measurements is merely loss of the boom, and better, more extended bass. The change is dramatic, and for someone accustomed to listening to L100s, it very likely takes some getting used to; it may also require readjustment of the MF and HF levels, "presence" and "brilliance" to achieve a better balance, as others have suggested here.

Then, the logical question: "If closing the port on L100 gives it better bass, what happens if you then provide the L100 bass driver with the larger closed box the sim programs suggest it really needs?" That led us to these 3 cuft C36s, wherein we're concurrently also attempting to overcome more of L100s "shortcomings" with a compression driver, horn, and a proper crossover....

alexkerhead

11-06-2006, 05:06 PM

I see what you are saying.

Seeing how I adjust my EQ, the closed 3cu.ft design would alleviate the need for acoustic equalization.

You wouldn't happen to have a schematic of the crossover?

Since I cannot afford JBL crossovers, I will be making my own.:)

The only thing I am saving up for that costs a lot of money are the compression drivers and birch plywood.

Zilch

11-06-2006, 05:19 PM

Seeing how I adjust my EQ, the closed 3cu.ft design would alleviate the need for acoustic equalization.Yes, that's one element of this. The BIG one is you'll be getting HUGELY better extended bass, as well. (I'm listening to it RIGHT now, from the other room, Larry and Lee again. :thmbsup:)

Alex, I am trusting that by the time you get all of this together, we'll have an appropriate crossover design to work with. JBL 3120A is just one that I use in testing here, because I have it, and it offers some versatility for that purpose, getting me quickly to something listenable, and telling me, generally, what will be required for that. To replicate it would require having the tapped inductor (L3) used as an autotransformer in it for attenuation:

http://www.jblproservice.com/pdf/Network%20Schematics/3120A%20Network.pdf

There are better options. Just for information, I'm running HF boost at max and HF gain (MF, kinda) at med. That establishes the requisite compression driver compensation curve Johnaec alluded to above. Consider it passive EQ built into the crossover. Right now, it's similar to the green curve in post #2 here:

http://audioheritage.org/vbulletin/showthread.php?t=5376

oznob

11-19-2006, 10:20 AM

Yesterday, I stopped by The Zilchters to see what he had been up to. Oh, took the L111A's for the L110's to Daniel at Audivex to get a re-foam. Anyway, having not seen this thread I was curious about the two ways in the "ancient" looking cabinets, no ports BTW, with the very familiar looking woofers. :hmm: an acoustic suspension cabinet with 123 woofers?

Without much prompting, Zilch fired them up with some Jazz, Little Feat and others and what came out was nothing short of amazing! Tight, yes tight, punchy accurate bass, smooth highs and killer mids! Piano and acoustic guitar just jumped out of them. Cymbal crashes with good sustain and shimmer. Kick drums that sound like kick drums with no slop. Almost seemless transition from the horns to the woofers. I have listened to and had my share of L100 type speakers and these clearly bested all of them. The 123 seems to beg for an acoustic suspention cabinet, properly damped, getting frequencies below 1200 HZ. Kuddo's to Zilch for putting together what I feel is one of the best two ways I have ever had the pleasure to listen to!:applaud:

johnaec

11-19-2006, 10:45 AM

Yeah, I stopped over later myself. Those 2-way's really work well. I'd just gotten out of 3 hours of probably 95-100dB band rehearsal, so I don't know how much I could trust my ears, but they certainly played flat, with those little neodymium HF drivers putting out crystal-clear highs. And obviously, you're not going to get earth-shaking bass out of that particular 12, but in those cabinets, they far outshine the original L100's in terms of bass extension and smoothness.

I'm really surprised JBL hasn't come out with a nice 2-way home system similar to these. The nearest comparable I can think of is 4425's. Of course, with all the used L100T's and such available at low prices on eBay, whether it's a marketable idea or not, I don't know...

John

oznob

11-19-2006, 11:19 AM

Great observations John, maybe your next project?. Sorry we couldn't hook up yesterday. Mayby when I come down and get the 111's?

:cheers:

Zilch

11-19-2006, 02:35 PM

Quasi 3-way filter w/adjustable mids and highs derived from 4425's N3124.

Check me HF, please. I haven't built from this redrawn schematic yet; presently using HF section of factory crossovers:

http://www.jblproservice.com/pdf/Network%20Schematics/3124%20Network.pdf

HF gets additional fixed L-pad attenuation before the driver, value to be determined. (It's an adjustable right now; gotta measure stuff to get it right.)

Gonna try an inexpensive active biamp approach using T-amp for HF later this week. Parts in transit.... :thmbsup:

Zilch

11-19-2006, 03:24 PM

Thanks John and Oznob for coming by to listen and reporting your "findings" here.

I'm kinda stunned by these, myself.

[Must be the 10,000 monkeys in play at ZilchLab.... :p ]

Zilch

11-19-2006, 08:16 PM

... they certainly played flat, with those little neodymium HF drivers putting out crystal-clear highs.I've been liking this driver/horn combination since the first of this year:

http://audioheritage.org/vbulletin/showthread.php?p=90134#post90134

[Had to use it in something.... :thmbsup: ]

alexkerhead

11-19-2006, 09:53 PM

I am glad to hear they are sounding great, I should be able to start mine over the thanksgiving week.:)

Zilch

11-20-2006, 12:53 AM

In designing your boxes, Alex, consider that mine are now elevated such that the horn axis is 29" off the floor. Given the 50° vertical beamwidth, I have found that to be minimum height for seated listening. It also reduces the boundary reinforcement of bass from the floor.

I'll end up with either a plinth or tall legs under these.

[Or Eames table bases, or Nelson slat bench, or.... :hmm: ]

alexkerhead

11-20-2006, 04:53 PM

Is the difference severe enough to HAVE to have the raised?
Because mine will HAVE to be close to the ground.:(

Zilch

11-20-2006, 05:05 PM

It depends upon how far away from them you are listening.

Plot the 50° vertical beamwidth window from the proposed horn axis height.

Another option is tilting them back, i.e., "aiming" them upward somewhat.

I'm not sure you understand what I'm saying above, really. What I mean is consider making your boxes taller, and shallower and/or narrower to raise the horn axis height, while maintaining the 3 cuft internal volume.

Woofer moves up with the horn.

Another option: stack the horns on top of the woofer boxes, which are inverted so the woofer's at the top. That moves the horns up to listening height. Build separate matching enclosures for the horns later, like Altec Model 19....

Zilch

11-22-2006, 12:54 AM

I THOUGHT I had an easy approach to biamping these: T-Amp, active XO, DONE!

Not so FAST, Zilchster. Seems everybody has a different definition of "CD compensation." Of these three (top,) only the venerable 5235 with FFBREQ cards worked for this combination of drivers, though its dip at 3 kHz is too deep.

CCBREQ doesn't have the dip, but I don't have a set of those cards at 1.2 kHz, or specs for how to make them.

Sonic Impact T-amp (silver, lower right in first pic) is barely on running these compression drivers.

They all flatten the HF well enough, it's the summing that doesn't happen. Behringer (results not shown) leaves a bigger hole than the M553 (center).

Voltage drives tell the tale, bottom. Crossings from the LF drives: 5235 = -3 dB, M553 = - 6 dB, Behringer = -12 dB???

It looks to me like the Behringer calibration is just, well, wrong. It SAYS 1K2, but it's actually more like 800 Hz. I like that it goes flat at UHF, tho, for reasons discussed elsewhere here. Also, it has adjustable delay for the woofer, which works for time alignment on these.

None of them sound particularly bad, actually. Without measuring, I probably wouldn't even know. :p

[Series 60 comp and CCBREQ left yet to try....]

alexkerhead

11-22-2006, 11:35 PM

I have a couple small problems:(.
1. I do not own and cannot afford a active crossover.
2. It is unlikely I will be bi-amping them(maybe bi-receivering them).

Do you think this project is worth my trouble if it won't sound good setting on the small legs and being powered by a pioneer sx-1250?
If you don't think I should worry with it, I have some other stuff I can use the project money for.:)

I wouldn't want to build something that didn't sound good on what I own.;)

Zilch

11-23-2006, 03:44 PM

Do you think this project is worth my trouble if it won't sound good setting on the small legs and being powered by a pioneer sx-1250?50° vertical beamwidth is double axis height at 51.46" from waveguide acoustic center. [Oh NO, it's friggin' TRIG!! :banghead: ]

Also see http://audioheritage.org/vbulletin/showthread.php?p=135182#post135182

[How high are yer ears? :p ]

Zilch

11-23-2006, 05:02 PM

1. I do not own and cannot afford a active crossover.
2. It is unlikely I will be bi-amping them(maybe bi-receivering them).
Price out the parts to build the passive crossover posted @#64, above.

I'm merely exploring biamping as a potentially cost-effective alternative; they sound spectacularly good with the passives.

The T-amp for the HF is $28 at Parts Express:

http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=300-952

The Behringer XO I tried is $129:

http://www.partsexpress.com/pe/pshowdetl.cfm?Partnumber=248-668

BUT, the JBL 5235 works the best so far, and Giskard is now helping us figure out how to make what may turn out to be the correct EQ cards for these:

http://audioheritage.org/vbulletin/showthread.php?t=13202

5235s go for as little as $35 on eBay. The cards can be easily made from scratch on perfboard for just a few bucks.

Read up 5235. It's got a selectable subsonic filter built in to protect your woofers from altered consciousness, as well. I'm hoping I can make it work as an option to the passives with these:

http://www.jblproservice.com/pdf/Vintage%20JBL-UREI%20Electronics/JBL-5235%20manual.pdf

I wouldn't want to build something that didn't sound good on what I own.;)
Send me your baffle layout, and build the boxes. You are but $50 away from a major revelation.... :yes:

I have some other stuff I can use the project money for.:)PS3? :p

alexkerhead

11-24-2006, 04:52 PM

PS3? :p

I understand the beam width of the horns and my seating arrangement should be just right for the center axis at the proximity.:)

PS3? LOL, perhaps you haven't seen what I play games on?
http://ubertech-museum.com

Take a look, I don't actually play any video games, but I do collect vintage computers on top of my audio addiction.
:D

Thanks for the 5235 recommend zilch.
I don't have enough money for birch yet, but I am getting there. Just had to buy some books for next semester, just the cisco book I needed was over a hundred bucks.:(

jcrobso

11-24-2008, 10:17 AM

Back in the late 1950's when I started getting interested in Hi-Fi the battle was raging, bass reflex vs sealed box!
Acoustic Research (AR) speakers were the rage in the early 1960's.
The concept was to make the LF driver with a very lose(complaint) suspension, the box was filled with fiber glass and sealed tight. The trapped air stiffens the LF driver, the box is a variant of the infinite baffle. The box filled with fiber glass tricked the LF driver into thinking that it is in a larger box than it really was.
It would be interesting to see how and L88 woofer would react if you filled the box with fiber glass and plugged the port. I'm might try this with one of my L88s if I run out of things to do.
In 1964 I had chance to spend 3 hours just listing to just speakers, JBL,AR, Jensen, Empire, etc. I did a lot of comparing AR to JBL and I all wise liked the JBL ported boxes over the AR, I have been a JBL person since then. John