[T4Man]

Hey all,
Just curious about this after someone else mentioned getting a pair. Being so-called "studio monitors" isn't it the idea to set them on a shelf above a mixer board? That way the mid and tweeter would be at ear level, or they could be set on their sides so you have a TM on one side of the baffle. It's still a questionable driver layout but this way the measurements would made on-axis with the tweeter. Am I wrong?

[Hobbsmeerkat]

We did measure them initially with that in mind, between the tweeter/mid.
Even in those cases, they didn't measure well regardless of where we measured them from, and the off-axis measurements show that pretty readily, and with the speakers being non-mirrored pairs, you're getting different responses from each speaker.

When we designed the new crossovers, we moved the reference axis up to the center of the top woofer, closer to where a normal person would sit with the speakers on 12-18" stands.
While better than they were, they're still not a great speaker for studio work, and I suspect no one will be using them for actual studio work at this point.

[T4Man]

I suspect no one will be using them for actual studio work at this point.

  I have no doubt of that!

[Rusty Jefferson]

At the time they were introduced most recording studios had large format monitors in the control room and they were recording pop, rock, and disco music. The studio I saw 4311s being used in had them in dedicated mix down rooms to keep the control room free for recording. The lore is JBL was asked to design a small monitor that had the characteristic sound of the 604 based control room monitors (Altec and UREI) that virtually every studio in America was using. Forward midrange was the sound of the time.

That same studio built structures off the front wall the same size as the speaker cabinet outside dimensions that came out about 3' over the mixing desk and tape recorders and then turned inward (toe-in) about 20 degrees and came forward another foot or so. The engineer sat at the console and the 4311s were suspended above the console and just arms length away, toed in on axis. 4' or so from the front wall, 6' from side walls or ceiling. They were basically big headphones in a room covered with absorption panels that was completely dead. They were not intended to be listened to from 8' away with boundry reinforcement, or listened to off axis.

Everything in life needs context. Danny didn't say anything that wasn't true about the speakers, but there was no context. Mainly, that they're 50 year old speakers. 50 years from now someone will post a video (if there is still video) saying "...look at these old speakers from 2024!  They have these horrible things called passive crossovers that cause all kinds of problems with phase shift and stored energy and blah, blah, blah... What were those engineers thinking?!... " 

Would anybody post a video on the YouTube comparing the performance and handling of '74 Pontiac Firebird to a '24 BMW, completely condemn the Pontiac, and then sell a kit to improve the performance of the Pontiac to be more like the BMW?  "C'omon Man, what at are we even doin' out here?"  You gotta have context.

[Tyson]

There are people doing conversions of classic cars to electric drive trains.  Some people love the old forms but also want modern performance. 

[mlundy57]

At the time they were introduced most recording studios had large format monitors in the control room and they were recording pop, rock, and disco music. The studio I saw 4311s being used in had them in dedicated mix down rooms to keep the control room free for recording. The lore is JBL was asked to design a small monitor that had the characteristic sound of the 604 based control room monitors (Altec and UREI) that virtually every studio in America was using. Forward midrange was the sound of the time.

That same studio built structures off the front wall the same size as the speaker cabinet outside dimensions that came out about 3' over the mixing desk and tape recorders and then turned inward (toe-in) about 20 degrees and came forward another foot or so. The engineer sat at the console and the 4311s were suspended above the console and just arms length away, toed in on axis. 4' or so from the front wall, 6' from side walls or ceiling. They were basically big headphones in a room covered with absorption panels that was completely dead. They were not intended to be listened to from 8' away with boundry reinforcement, or listened to off axis.

Everything in life needs context. Danny didn't say anything that wasn't true about the speakers, but there was no context. Mainly, that they're 50 year old speakers. 50 years from now someone will post a video (if there is still video) saying "...look at these old speakers from 2024!  They have these horrible things called passive crossovers that cause all kinds of problems with phase shift and stored energy and blah, blah, blah... What were those engineers thinking?!... " 

Would anybody post a video on the YouTube comparing the performance and handling of '74 Pontiac Firebird to a '24 BMW, completely condemn the Pontiac, and then sell a kit to improve the performance of the Pontiac to be more like the BMW?  "C'omon Man, what at are we even doin' out here?"  You gotta have context.

My takeaway from all of Danny's upgrade videos, and this goes for current as well as old speakers, is that it's not about how the speakers were intended to sound and/or be used by the manufacturer, but how the current owner of said speakers wants to use them today.

Similar to Tyson's example, I think of it like my house which was built in the mid '70s. The builder built the house the way they thought it should be for a particular type of client, a family of 5 with 3 kids old enough to have their own bedrooms but young enough that small bedrooms were appropriate; a small lightly constructed deck; and single pane windows with storm windows. While that was fine for the intended buyer of the time, it didn't exactly fit how my wife and I wanted to use the house when we bought it in 2008. We tore off the small flimsy deck and replaced it with a much larger and stouter one. We also replaced the windows with modern energy efficient thermal windows, remodeled one one of the small bedrooms into a larger room for leather working, and put up a fence around the back yard for the dog among other changes.

Some might argue that we shouldn't have bought the house if we weren't going to use it as originally intended but should have bought one that was built the way we wanted. A valid point but there were things we did like about the house and property.

[Rusty Jefferson]

I think you guys are missing my point.  It's not about what people want to do with their stuff. What annoyed me was he absolutely eviscerated the engineering group at JBL for building the speaker.....50 years ago, with driver/cabinet technology that was available to them at the time. Criticism I think was uncalled for.

It's fine to say "here are the problem areas, and how we're going to improve them." But looking at a 50 year old product that was purpose built, with knowledge of what can be done with today's technology, and condemning what they did as terrible is not cool. Danny is better than that.  These weren't designed and sold last year, and worthy of engineering criticism. In the early '70s nobody measured vertical off axis or worried about cabinet diffraction because the marketing people wanted a flush mounted grille, and they were intended to be listened to at about a 3' to 4' distance, on axis. Context.

[Tyson]

Fair points.  And I don't disagree with them. 

On the other hand, there's a lot of badly engineered and poorly built audio gear in the world and exposing that in a direct manner with measurements is an invaluable service to the audio community.  It's also the reason I am a big fan of Erin's Audio Corner, where he goes even further using a full Klippel machine. 

[Rusty Jefferson]

Appreciated. Exposing 50 year old technology as bad, and especially calling out the engineers, requires context. As far as I know, Erin and Amir aren't calling out poorly implemented equipment from the Nixon administration era.

[mlundy57]

I see. You’re saying it’s about how it was said and that the point could have been made more tactfully.

[Rusty Jefferson]

Please see the example of Troels Gravesen redesign of JBL L-100 crossover from his website. Nothing wrong with this.

http://www.troelsgravesen.dk/JBL_L100.htm

[WGH]

I have the original JBL L100 (4310) speakers from the early 1970's I bought new. The JBL 4311B uses different drivers than the 4311 so the crossover redesigns either by Troels Gravesen or Dennis Murphy would have to be adjusted.

The JBL L100/4310 uses the 123A-1 woofer, the LE5-2 mid range, and the LE20-1 tweeter.

The JBL 4311B uses the 2213H woofer, LE5-10 mid range, and LE25-2 tweeter. At first the L100/4310/4311 used similar drivers, then different drivers for the 4311 were used in different years.

The general consensus is to change out/upgrade the caps and continue to listen to the speakers as they were designed, that is what I did. When you listen to old recordings you will hear the music exactly as the engineer intended, which is probably why old recordings are re-mixed and re-released.

The different JBL L100/4310/4311 crossover designs are explained in detail in the links below:

A guy who tried both L100 crossover designs
https://audionostalgia.co.uk/jbl-l100-crossover-upgrade/

Troels Gravesen redesign of JBL 4310 crossover
http://www.troelsgravesen.dk/JBL-4310.htm

Dennis Murphy's JBL L100 crossover design
https://forums.audioholics.com/forums/threads/the-vintage-jbl-west-coast-sound-becomes-the%e2%80%a6.25014/

[Danny Richie]

What annoyed me was he absolutely eviscerated the engineering group at JBL for building the speaker.....50 years ago

Engineering group? What engineering? They let the woofer play full range. They added one cap to protect the mid and one cap to protect the tweeter and that's it. There was no crossover in them. The response was rough. There was comb filtering in every direction. The cabinets had no bracing and stuck out past the front baffle (edge diffraction). The cabinets resonant like crazy. They didn't even recess the drivers.

There is no way I can sugar coat all of that. They could have done a lot better even back then.

[WGH]

The first time I opened up my JBL speakers I was confused, were they really running the 12" driver full range? I guess so, weird, totally weird. Reviewers talk about cheap crossover parts, how about no parts? The thing is it worked, everybody loved the sound in spite of all the flaws, I guess you had to be there in 1972 to understand. The L100's had no deep bass, the response rolled off real quick after 40 Hz, but that 40Hz was glorious for the rock n' roll we listened too. The L100's were also amazingly power hungry (76dB), they really needed a high power amp to strut their stuff but who could afford that in the early '70's. When I finally paired my L100's with a 120 watt high current amp I discovered what I had been missing.

My L100's actually started out as L88's. I bought them new in 1972, on sale for $188 pair. I did major surgery to them re-positioning the tweeter, and installing a sealed inner box for the midrange driver and the new crossover based on directions I received from the JBL factory. The L88's woofer and tweeter are the same ones used in the L100's in 1972. The 5" midrange is the LE5-2, the same as in the L100 and 4312.

While the speakers were apart I also did massive internal bracing and added another layer of 3/4" MDF to the speakers back, the results were a cleaner presentation with deeper, more defined, punchier bass since the cabinet was no longer flexing and damping the low frequencies. I used the pot to balance the new midrange and tweeter, I got real close and turned the dial until there was a solid center image between the two drivers. Back in '72 we didn't need no stinkin' measurements. 

Not pretty but I keep the cloth grills on and they are my shop speakers after all.

[77SunsetStrip]

Appreciated. Exposing 50 year old technology as bad, and especially calling out the engineers, requires context. As far as I know, Erin and Amir aren't calling out poorly implemented equipment from the Nixon administration era.

Is anybody sending Erin or Amir 50 year old speakers to measure, listen to, and potentially improve?  NO.  So not an apples to apples comparison. 

[Letitroll98]

We had JBL something's in our 70s bachelor's pad.  I couldn't tell you if they were 4310 or 4311 as they weren't mine.  Our third roommate was unemployed and drunk for the entire time he was there, but he has a stereo system thus his space on the coach secured.  They were three way JBLs with a 43xx on the label, that's as much as I can recall.  I hated them and thought they sounded terrible run by Radio Shack separates.  Yes, the Shack had separate components back then and that might have been the source of the sub par sound, who knows.  After my marriage I moved on to Scott then Allison speakers and never looked back.

[Danny Richie]

Is anybody sending Erin or Amir 50 year old speakers to measure, listen to, and potentially improve?  NO.  So not an apples to apples comparison.

Erin is a great guy and I like his reviews, but he is a reviewer. He doesn't design upgrades. And Amir.... Well, he can run the measuring device. I'll leave it at that.

People send us vintage speakers because there is a nostalgic or emotional attachment. They like and want to keep them. However, they also would like to listen to them and enjoy them. Technology has come a long way since then and transforming them into something that is much further up the performance ladder is not hard, and that is what we do.