When my ears were young and not buzzy speakers were crappy. Now my ears are crappy and my speakers are great (X- statiks). Thanks for the videos and my speakers GR research.

You deserve a ton of likes for just subjecting yourself to this disaster.

I remember all vintage speakers very well. They sounded killer when I was in my teens! Not so much when your older. Great job! Kudos on you schooling OCD Mikey on the Magnapan! 😊

I bought a pair of HPM60s new in 1976. Blew the woofers at a frat party in 1980. Replaced the woofers with some from Frasier in Dallas. Been using them continuously for almost 50 years! Now using them in my garage to rock the neighborhood. Looking forward to the HPM60 video.

I feel so bad for you, Danny. These old speakers are huge headaches to deal with. Thank you for your dedication and patience and doing the best you can with these beasts.

Great job again, Danny and Hobbs. Great to see you breathing new life into these oldies.

Thank you for this information! Ordered my upgrade kit with anticipation of hearing the difference! Well done sir!

I always watch right to the end! Another great upgrade and very interesting to see the filler driver applied like that! And what a huge bass driver, I would've expected to keep ringing more than it did. I was just thinking of pouring epoxy into the front to level out the front, that would alter the vintage speaker, but it might deal with the diffraction a little better.

loved this one. I used to be in a band that used a recording studio, where these were the main monitors, but they were wedged into the corners on shelves. We used to get some real weird sounding mixes from that studio.

I bought a pair of the upgraded version 4312 JBLs brand new in 1984 that were a huge difference from the JBL L40s I had.. used them with my Nikko 100 Watt receiver and was able to crank up the NOISE without blowing up woofers and tweeter's like the little ones did. But that's what they were made for I guess. Playing LOUD! I traded them in for DJ equipment in the late 80s & always regreted it until I knew what good speakers were all about. Nice watching this video now and knowing I made the right decision years ago. Thanks Danny! 👍✌️

I think is one of your best videos and upgrades this one and the HPM100, you said a great true about in the late 70's there were not measuring equipment like TEF to help designers in making the ideal crossovers and that's why this vintage speakers can be improve vastly with your work, anyone owning a JBL 4311 would be glad to pay those 730 dollars in order to make their 4311 to sing much better, I was waiting at the end that you say that after the new crossover you like a lot this speaker, maybe some day another guy bring you the L-112 which is a bit better than the 4311, thanks for this job

When I worked at Motown Hitsville Studios (Los Angeles) in the late 70's early 80's, these speakers were used all the time. They would sit up on a shelf on top of the consoles as near field monitors. I can't begin to list the albums mixed on these speakers, I constantly found the mid range drivers connected out of phase on some and not on others. Whether they came like that from the factory I had no idea but I had to go through and get them all to match. They were horrible but recording engineer theory was if you could get mix to sound good on them, they'll sound good on the radio.

Kudos to a manufacturer that still sells replacement parts. Try that with other older speakers.

I love these videos. I remembered drooling over these as a kid. Over the years I almost pulled the trigger several times but they always got away. It seems like I dodged a bullet. Im still interested in some Kenrick Sound modified JBL's but until then im good.

But still… back in the day I used these speakers as monitors for recording and mixing music professionally and guess what… I loved them! Of course they weren’t perfect, but they gave me mixes that translated very well to other systems and radio/tv. I had a hard time finding replacements when the time came… And I have to say that I enjoyed working with them. If I’d still have a pair I would certainly try your upgrade kit for sure…

You made the best of an impossible task. On the horizontal off-access, if I recall correctly, it's not possible to have the tweeters on the outside for both channels because JBL did not mirror the driver arrangement for left/right speakers in the 4310/4311 series. The 4311B and Pioneer HPM-100 were my two favorite speakers when I was a kid back in the mid-80's. I was ASTONISHED by what you were able to do for the HPM-100. Not surprised that the 4311 was a bigger challenge, but congrats on the results. I'm almost tempted to pick up a pair to give your upgrade a try. :)

Thank you so much for sharing your knowledge and experience with us.

Great Video! Nice to hear about these old (in your words) disaster.

Excellent vid. By the way, my Pedest'ale Tower speakers recapped and lined with No-rez are a testimony to Danny.

The 4311 was supposed to be the studio monitor version of the "legendary" L100 back in those days....

I was thinking the same thing as you were discussing the problems: basically make it a two-way with the midrange filling in a bit at the bottom.

One thing for sure after reading 303 comments... Speakers are like food. Some people like *this* and some people like *that*

Great information as always.

Excellent work Danny. I can only imagine how harsh and hot it sounded originally.... The JBL almost reminds me of the older horrible sounding speakers that came out of Japan back in the day, with little to no effort given to accurate sound quality. Well done!

When I was a young lad, this was a grail speaker. But never had the space, so i eventually settled on a pair of Advents.

My understanding is these JBLs were monitors intended to be mounted above a mixing console. That is why the tweeter/midrange below woofer. Back in the day there were listeners that loved them and those who hated them. Old saying .... "JBL" means "Junk, But Loud"

When I was young (talking 70's here) all the guys that were several years older all had those giant Pioneer receivers (or maybe Marantz if they were really cool) plus those JBL L100's Wasn't until I got to college and heard a guys rig who had modded Dynaco tube amps, the Chartwell version of the BBC monitor w/ a Linn LP12 deck. Changed my life. I realized how things were supposed to sound.

I have been watching your videos. Well done!! You share allot of info., I am sure that everyone out here appreciates it. It seems like these companies make their products but do not test them to see the performance. Maybe they don't care?? We the average consumer have to rely. On them to makes a good product for us. Maybe the people that design this stuff lacks the knowledge. that you have?? Or once again the don't care just want the money?? Nice video.

i remember being in several recording studios in LA in the late sixties and 4311's were the standard replay speakers...amazing.

I'd redo the crossovers, test each driver for frequency response, and then redesign the crossovers!, great video

funny, growing up with a pair of these and other vintage speakers, i was so happy with them when they'd thump and sizzle and now? i use morel dome mids and tweets and have no wish to change back to the harshness and slam..age helps us learn!

Danny, interesting upgrade. It would have been really interesting to hear your thoughts on the sound before and after as there is such a huge change in design. Perhaps some thoughts on what the original design goals might have been as I’m sure there would have been a reason for the response you measured. To balance out mid/bass gain from a mixing desk or being flush mounted? Also do t forget that in a nearfield situation in a damper room, the off axis responses are not as important. Also, how did your upgrade filter affect power handling with the tweeter playing so low? I know you love the spectral decay, but I think you should show THD at various SPL outputs (up to 96dB @1m ideally) as this really is the only way to validate the usefulness of the design.

Looks good! Danny just out of curiosity, what was a better speaker the CerwinVega! You just did or this JBL? Before and after.

These kicked ass in their day,all we had was our ears,we trusted brands. The old pioneer hpms were screamers to me,I gave mine to my little brother,those tweeters also had control knobs,that didn't do shit. Great video I love these vintage speaker redoes more than your doing new ones.

Wow... This one is interesting to me, because I heard a pair of these in a dedicated space with an old Marantz receiver. They had stands that raised them up about 8" and tilted them back a bit. The damn things sounded excellent!

It's amazing how all these speaker companies survived all these decades.

Thriller was mixed on speakers from this series.

It is amazing how much crossovers can balance and clean up sound.

Can 35yo crossover components cause ringing buzzing at certain frequencies? Or the old wood? I lined the insides with mat, nothing changed. It’s around 120 180 and 340 hz when doing a sweep. Rare Radian Engineering cabinets. Single point source with diaphragm mounted on the back of the woofer. I have 3x 10” and 2x 8” used in 5.1 setup.

a friend got new 4310s in the 70s and try as we may, we couldn't get them to sound good fin multiple positions, on the floor, on chairs against the wall and away about 3', sealed port, open port, no grills,etc. they would only sound acceptable EXACTLY on axis aimed straight ahead, and also at low levels for background or late night listening. he quickly sold them for the accommodation price he paid (he engineered for KPPC-prog rock-before it became KROQ in LA, actually located in Pasadena CA). he then went to work for Infinity Systems and the sound was WAY better from a variety of their speakers which he got to bring home. the L100 in general, which the 4310 and 4311 series were related to, were boomy, hard in the mids, and harsh in the highs. the new version, evenwith the new drivers and integral stands, are still too prominent in the bass which obscures their actual lows and overshadows any improvements in drivers. current pricing actually rivals original pricing adjusted for inflation. the fans of the old and new versions are certainly welcome to their choices but the new JBL Synthesis series are exquisite if chokingly priced in the five figure range.

Speakerlab, a DIY speaker kit store up in the Seattle area, had showrooms that you could go and demo their products in. This was around the late '70's. They had a set of JBL century 100 that they kept so folks could A/B their competitive product in the same price range. Speakerlab use air core inductors early on, the drivers were placed on the front baffle in line, the midrange crossed over at 500 Hz and had a rubber surround inside a dedicated dampened enclosure. The 12" woofer 3 way kits they had were the model 3, which used an Audax 1" soft dome linen tweeter, or you could opt for the model 4 with the upgraded Klipsch style Electro Voice T-35 compression tweeter. Both these would trounce the JBL, no contest.

Looks like your final result made a kick-ass rock-n-roll dorm room champion. Great party speaker. That thing looks like tons of fun in a dorm room or basement full of people with appropriate amounts of adult beverages thrown in. Well done, and once again, kudos to JBL for having/selling replacement drivers. Big Time thumbs up.

It would be easier to replace the tweeter with a good modern soft dome in low Fs. The change is quite drastic, previously the 5-6k region had almost 100dB and now there is a dip there to approximately 86dB. Someone will say that changing the tweeter will mean a different speaker. But with such different frequency response it is also a completely different speaker. Objectively better, of course. Anyway imagine how many recordings of that time was screwed up by such "studio monitors"...

I n the 70's so many speakers from Japan and the US were made just like these and only GR can make such an amazing improvement

You should make a playlist just for the vintage reworks. I'd watch 'em.

The JBL 4311 reminds me of the abrasive performance of the Pioneer HPM 100... both speakers designed Bart Locanthi BTW.

The woofer and the mid can be time aligned to the tweeter just like in a 2 way design where you time align the tweeter to the woofer or vice-verser. In the end there will be 2 crossover points where the woofer will crossover with mid and tweeter will align itself with the mid and the mid will be crossed over to the tweeter. Its what I will call a modern 3 way design. It's complicated but with modeling software it's easy

I completely rebuilt a ragged set of the L100s last fall. I replaced the factory caps with Mundorf Oil Caps. Someone had put mids and tweeters from other JBL products in their respective holes. I wish this option existed then but then I'm not sure I would have pulled the trigger at this price, however. Spending $700+ is just too steep for this speaker. Unless you're never planning on selling them.

Is suspect there is one inherent advantage to the woofer running wide open; direct connection to the amp, ie., zero additional inductance! As I recall, a short time later, the 4430/4435 bi-radial monitor platforms were significantly better ... ie., output, linearity, extension, coverage.

Way back in the dark ages, I had a pair of these. Wanted them so bad I could taste it. Really liked them at the time. Drove them with a Marantz 2250. They were so much better than what I had previously. Was the first real speaker I had that made a real attempt as bass. Ironic Harman International a few years ago released an updated version of this (L-100) with a retail price of 4K. Have not heard them so can't comment on their sound but the claim is they measure much better than the older L-100 (and 4311). Not sure if its due to their price or SQ but they have not been selling like hot cakes the way the originals did. Going from memory all the big JBLs had a box that would resonate like crazy, even the big L-300s but folks still loved them.

Personally I would leave the tweeter in there as a hole-cover and take it out of the circuit, replace the mid-range with cheap but usable full-range that could reach down to your baffle step transition. Install it in a capped tube packed with insulation so its not sharing airspace with the woofer then flip the whole thing on end to get the full range on top. Make it a simple 2-way and choke that woofer out. Target crossover would probably be closer to 400hz.

Before / After test would be essential with a mic for us!

I'm curious what it would cost to send some older Beethoven Grands (2005 era) from Washington to Texas.....probably a lot! LOL Dang, I love what you do man, I really do! Keep them a coming! ⚽Also, do you have an EPL team?

I liked the JBL 4311 (and the L100 sister) as it was.

Thags cery true, maybe one of the worst for imaging and not the best blending of frequencies, but they sure do make some good looking drivers and speakers though! These look especially good with the orange grilles and those white aquaplas woofers, they grab your attention everytime.

Listen up all you vintage jbl fans, the man speaks the sad truth unfortunately 😮‍💨

I understand the bashing of these old JBL monitor speakers. That makes me want to hear your opinion on the 120Ti, 240Ti and 250Ti. As these models gets a lot of love.

where do u get OEM tweeters LE-25 ?

I added a 10" powered subwoofer to my Marantz / JBL set up and my 4311Bs sound better than ever. I may try your kit if the big improvement the sub gave me ever wears off.

Wow - throwing drivers in a box - pretty much sums it up! The front baffle is crying out for a couple of ribs/braces - the 3 holes with the narrow webs between them - probably are letting the panel flex a lot. Is the midrange driver a sealed back? You don't mention a separate enclosure, so it seems that it is?

an interesting listening test would be to compare GR-modded 4311 / L100 spkrs to a good, healthy original set. use a very good (& also healthy) vintage amp. select only rock music from bitd.

I'm very curious about the vintage Pioneer speakers. Back in the late 80s and early 90s, I dismissed them as JBODs. (Just A Bunch of Drivers - stuffed into a box). To me, they looked and sounded like that. I was also not impressed by all the chromed plastic. But then I fell in love with the Kenwood LSP-9000Ds. Quite honestly, those were also JBODs with plastic "beauty rings", but I was young and still had a lot to learn. I'm curious about whether I was right about the Pioneers back then.

How’s the new three way design coming along?

I remember some of the old JBL speakers. I was never a fan compared to some of their competitors. I often wondered what people saw (heard) in them. I was a fan of the ESS Amt tower that Team Electronics had back then. Let’s see how Danny does.

My 4411s have a MASSIVE crossover so I'm very surprised that these only have capacitors on the back of the drivers.

I have a pair of JBL 4312 speakers. I don’t know how they compare to the 4311s internally but externally they seem the same just the other way around with the mid and tweeter above the woofer. Do you think your upgrade kit would work well with my 4312s?

Danny I want to know what are your top five favorite vintage speakers that don’t need any or at least not a lot of work.

Danny, Can your upgrade kit for the 4311's be used with the L100's?

Another big problem with this speaker: the Qts of the woofer is close to 0.5, so it really wants to be in a sealed box. In JBL’s reflex box, it has a nasty peak around 55-60 Hz, below which it drops off rapidly. In partial defense of JBL, it was designed before Thiele and Small’s seminal work.

you probably know this one but back in the 70s and 80s did they even have the equipment to measure and design crossovers like they do today? cost cutting aside the major brands seem to be making a lot better balanced crossovers than they once did. some may add a deeper sound like a drop at 2khz but it's intentional not accidental.

Would like to see the crossover you made for it in the video.

Perhaps an Option B of a new mid? One that would go low enough?

Any reviews on how this upgrade sounds and not only measures? i'm very interested because i love how my speakers sound generally but boy they can be harsh in the upper mid. i'm guessing this should fix that? i feel like at 700$ its a tough gamble..

Thanks.😊

Troels Gravesen talks about the original L100, and said the crossover was a ‘mess’. Good drivers, poor XOs.

The Troel Gravensen upgrade crossover came out over 7 years ago.

Will you test an AR2ax speaker and provide a kit? These were well liked and huge numbers were sold in the day

Chuck a bunch of pretty looking drivers in a big box with lots of ting and boom, That was the 70's! Nice job on even attempting to tame them.

I have just restored a pair. Wow What a sound

It would have been interesting to see the horizontal and vertical off axis response changes with the speaker flipped upside down.

Dan thinks he is the savior to the loudspeaker world , these speakers came out in 1973, professional studio Monitors , they are enjoyable ( re cap them to save the tweeters) and a great piece of audio history. I bring mine of now and then . Most of the older jbl’s are very well made and enjoyable to listen to.

I'm surprised you didn't address that the woofer is physically 180 out per JBL plus, the response below 100Hz down to 60. We know that speaker pretty much stops reproducing below 45Hz. Now, recording engineers as myself used these pretty much exclusively from 71 (4310) through mid to latter 80s. The primise was- "you can hear the songs as the recording engineer balanced them"

I love seeing the upgrades more than expensive new speakers being ulgraded

What state are you in. I have the same speakers that i would like to do the same thing. Or do you sell the kit?

Danny.... Love this video on a studio classic..... but why oh why does your 3rd plot line need to be Yellow? It's so hard to see yellow on white, and I'm watching on a calibrated monitor. (maybe I need some Clarity caps in my 4k monitor??)

I always thought the positioning of the drivers was odd , to say the least , but then I thought that maybe JBL knew something that I didn't.

The filter working for the JBL 4311B Monitors ????

Equalization really helped a lot back then.

Some of us knew they sucked when everyone else wanted them! And laugh like crazy at those suckered into the rerelease of the L100!

LOL...JBL fans gonna key your car! (but they crank, man!) I'm always amazed how many really popular speakers just suck....and people love 'em anyway.

Have to agree with Danny on this one. I had a set of 4312’s. Horrendous

Lol! I have these speakers in my office connected to a McIntosh MC2300 Amplifier. They get loud, but lordy they sound terrible.

I wonder what he thinks of the more expensive JBL studio series vs. these. I think these were the mass market crap that JBL produced vs. the much better larger 43xx models and such...

Would the kit also apply to the 4311b speakers?

When was this speaker available? Anyone know? No discussion of how they sound?

At 0:45 yep, that's what I was thinkin. Otherwise, JBL makes some great stuff, newer stuff that is. I mean their Studio 590's for example, on sale at $400..... Go try to beat it from any brand out there at that price point! I have 4 of them, and right out of the box they measure so good, I don't even bother to EQ them. They are ugly, but they sound like they measure, just very good. These dinosaurs you were trying to bring back to life, well, ya can't shine poop, it only smears, right? In something like this ya just have to replace drivers, no amount of EQ crossover work is gonna fix this kind of broken. I understand the orientation is by label, but I'd listen to upside down if it were me. Anyway, I love this stuff, the show and tell, the real science behind the sound. Cheers 🍻

Wow! We as diy RS have better technology than the big manufacturers did in the 70s.

I know the mid's and high's are where most of the magic happens, but what if there are issues below 200Hz?

I googled it and manufacturers started to use anechoic chambers and swept frequency testing in the 1930'a

Would not just replacing the midrange be cheaper AND better? The range from 500 to 6K is covered by MANY wide band 5" drivers.