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Wow, thanks for editing it for those that asked for a shorter version. I didn't see the longer version, but I appreciate your dedication to your audience, Dave. One of the best RU-vidrs I've ever subscribed to. Top dude!

Excellent repair video Dave. I especially appreciate the difficult soldering of the main chip. You're a professional and strive for high quality. But I'm a hobbyist and it educates and encourages me when I see that everyone has difficulties. Thank you for not editing out that portion.

Before I retired I worked on cable headend equipment and I must have changed a thousand tiny chips like this in the video. I found out that using a new straight edge razor on each job to slice the legs like you did in this video was the key to a clean job with no board damage.. For me that was the ticket because once the chip is removed you can carefully sweep the cut pins away followed with prepping the board for the replacement chip. Don't miss doing that kind of work and yep I'm loving retirement.

For what it's worth I watched the longer version and I appreciate that you left it available! I really like the longer videos.

That's a great idea, mate. Having the full video gives us the insight into the nitty-gritty, while the overview video gives us a good feel for what's in should we be looking for that sort of content for our own education. Also makes good use of all your recording time and efforts for people who need it. Winner winner! (You know what comes next)

Will definitely be watching the 50min version! Thanks Dave

Actually using a DSP allows you to use stuff that's impossible in analog like FIR filters. You take the impulse response of the speaker with no filter, then apply a reverse FIR filter to correct it. You can get much better results than with IIR analog filters. Almlst completely flat response in the passband, very fast rolloff crossovers, etc.

I like repair videos and loved this one in particular. The fact that you are feeling your way through this without the benefit of detailed documentation makes it a great learning tool for me... thanks, Dave ... from Dave

Gday from NZ...honestly mate the longer your videos the better...just my opinion gotta have your commentry and banter! cheers from NZ

@Dave The ADC/DAC and DSP is for adaptive equalization to create a flatter frequency response. Because each speaker is it's own amplifier, speaker, and enclosure, they can digitally modify the audio signal to boost and cut certain frequency bands in order to compensate for the mechanical and acoustic short comings of the speaker. The result is a flatter, more flattering, sound and an amplifier precisely matched to the acoustic characteristics of the speaker and enclosure. Since this is easier and cheaper to do in the digital realm, you get ADC's and DAC's.

Thanks heaps for doing both short and long versions. Much appreciated.

Hey Dan, one trick I've learned is to solder one pin on the corner first with an iron, and align it properly using that pin, and then solder the opposite pin diagonally. That will let you align the IC while only having 2 pins anchored for easy manipulation.

I've got a pair of these. I use them for my TV, awesome speakers. They've been on non stop for 6 years. This will be me soon.... lol

I've been a fan for 10 years or so an this is really one of the best videos. Very interesting insight in modern digital amp studio speakers and straight forward repair!

One trick I have learned when Soldering SMD ICs is to hand solder Pin 1 and the diagonal pin to align it. Its good to use a pointy tip for for this. Then u can proceed with hot air and solder paste.

Nice, I've watched many EEVBlog episodes through a pair of these!

Well, add this to the list of things I would have never been able to fix.

I love repair videos. And support the idea of full video on EEVBLOG2, and strimmed down on main channel. Kudos!

Working for a startup in the industry, I appreciate the audio content-although I try to keep to code and avoid anything involving solder.

My theory is the DSP has all the flat response parametric equalizer settings so the speaker is acoustically flat as possible at all volume levels. Lower volume levels, excursion at low frequencies can be increased to extend low frequency response without damage as it approaches resonant frequency of the port. At higher volumes, can limit to prevent driver damage or distortion...allowing much louder playback than normal. The magic in addition to Class-D amplification is what allows these small speakers do big amazing things.

Dude is a boss. I managed to fix my gaming monitor after following your videos. Thanks man!

Awesome. You shud start making troubleshooting guides for daily electronics which is normally just thrown away when faced with errors like this. Would really help with the " REPAIR IT ,DKNT THROW IT AWAY IDEA" which is great for the environment

Those JBLs are AWESOME sounding speakers.

Thanks for sharing. The interior design looks much simpler than I thought.

None of this 30 minute rubbish.. heading over to EEVBlog2

NIce work Dave, great that you showed that it still is not too complicated to isolate the fault even if most of the signal path is digital.

I used to work for Harman; a former coworker did firmware work on an older version of the LSR speakers. They used to use an 8051-based micro; I guess the STM8 is a step sideways? The micro is mostly for the custom control networking called HiQnet that all Harman pro gear speaks. You can control the volume and other settings for a whole set from just one speaker, or from your studio PC. There's an automatic EQ system for calibrating your setup to your room; they come with a calibration microphone and everything. That's likely what the ADC and DSP are mostly for, though they may do some additional stuff now as well.

yeah, most if not all of them have dsp; for active crossover, frequency response and phase correction. One of the main reasons why they all went active, it lets you iron out or hide some imperfections, and gives you great control over the sound of the speaker, as a whole product. Genelec has a system where you can wire up a provided microphone to do room correction, though Sonarworks does that as a standalone company.

Great repair video, I liked it and probably will watch the whole 50 mins version later. You could have tried getting a service manual, JBL has been very cooperative with repair shops (at least they were 15 years ago when I worked in the audio business). Personally I would have measured and tested the loads right away (old habit of repairing speakers), since it's a digital amplifier chip it might go into fault if there is an unexpected load. But that's just a different approach. About the "It doesn't sound as good as my Focals". I would say that "Red isn't as nice as blue", but I never heard the LSR308 and I am not a big fan of those cheap speakers being part of the LSR series. The series started with the LSR28P and LSR32 which cost 10 times more and part of a whole different league of speakers (I have owned both and still own the LSR32). Just for info : LSR stands for Linear Spatial Reference, their main goal was to achieve linearity in space and not only on axis (when sitting behind a huge recording console you cannot constantly stay on axis of a near field speaker).

Going over to the other channel because repair videos are awesome and I don't want to miss anything!

I've actually got these speakers. They're nice! And it's kinda meta to see them being torn down while Dave sounding from them. :)

haha - no way.. I have a LSR305 to repair so this is gold!

This was great. But I would have called JBL Customer Support and ask them what the flashing LED meant.. I did that with my JBL PartyBox 200, they told me it was most likely a particular driver chip. They admitted this has been an issue in the past. They were nice enough to send me the replacement part for Free, it was out of warranty, and after replacing it, the unit was fine.. Saved some time troubleshooting, but took away the FUN part of figuring out what was wrong! :-) Keep up the great videos!!!

Very nice interesting vid - just the right length and detail. 👍👍👍

For me it just sounds like two new videos to watch. Double the fun.

Thanks for this. I did 7 pair of KRK a few months ago, had the typical capacitor blow out from the conductive goo. Was a pain to fix, but our budget collapsed so we couldn't buy something better and I had to fix them.

winner winner! unless i missed it when you mentioned it, i'm a bit surprised you didn't immediately test the woofer/tweeter for shorts or open lines. some amps have an impedance measurement at power on and would report a fault when going under or over a set value so having blown components would summon a fault bit. :)

"Good enough for Australia..." :) I hadn't heard that one before. Nice video, It reminded me of back in the 70s' and reading the Electronics Australia TV Service column where the writer did an article each month about fixing peoples TVs, but a bit more complicated these days with digital circuits in a speaker!

DSP is has been a trend in the more high-end monitors and is now coming to less pricey units as the cost for integration has become so cheap. Way better (ie: higher order) crossovers, phase/time correction and frequency response correction can just be done in DSP at a low price, so it's not so much rubbish as a way to make a better monitor for cheaper.

I'm really suprised as a audio enthusiast. These speakers are really decent and sound better (subjectiv) then their pure analog counter parts. It just feels so wrong, but at the same time I admit that it is really hard to get an even frequency response with just analog parts. Digital really does the trick (again) ^^

Always learning something from videos like these.

I have the JBL LSR 28p monitors. You can tell your friends that I was here. PS if you see some for sale, you can't go wrong.

Thank's Dave for repair video! I'm buildind and repairing stuff, but never get hands on digital audio amplifier and even not realizing, that this kind of thing exists.. :D Very helpful video for new information. :)

Thanks Dave, great video. That leg amputation technique looks like fun!

Thumbs up baby! Tuning in from Colorado Springs! Say hi to Dundee for me. Cheerio Matey!

I have done this about 15 years ago with exact the same technique. With controllers which had lot more pins. And it works. Hundrets of times. Much faster than you did it ;-)

I would suspect the hiss you hear from the speakers is actually the ADC (analog to digital converter). DACs are almost always hiss free, even for very inexpensive ones, but the ADCs at the lower price points still have hiss under sub-optimal conditions. This problem is greatly exacerbated by the fact that the incoming signal level often varies greatly per consumer application (the ADC's incoming signal level), so the circuit maker is forced to design these circuits so they can tolerate a very high input signal to protect against overload. This works great for people indeed using a strong signal and sitting far from the speakers, but for the people using a lower level signal and sitting close to the speaker it means a compromised SNR, i.e., hiss. Keep in mind when you consult a spec sheet which implies an ADC chip has a great SNR it is being measured with an optimal signal coming in. People who use a signal that's 20 dB down from that experience a 20 dB inferior SNR experience.

I love how 30 minutes is short

Wow nice I really love the troubleshooting videos I always learn a lot Take care and have a good day Dave

Excellent repair and interesting fault! Thank you.

I figure that the convoluted ADC -> DSP -> DAC signal path is probably to equalise out the speaker response; to provide a predictably (flatish) curve.. it's probably hard to effectively flatten the response with purely analogue circuitry.

I have passive speakers from the 70’s that still work. This thing lasted what 3 years? What great progress we’ve made over the decades 🙄

23:05, that was so cool 😃😃😃

Great explanation and great soldering skills, thanks for the video!

Fortunately I didn't have to open my Adam A7X monitors when I had a problem. They sent a FedEx label and paid for shipping back to them.

Interesting, I have the 5 inch version of these. I didn't know that there was digital circuitry in there. I figured it was all analog.

Hi Dave, you should use chipquick part removal next time instead of risk damaging the PCB traces. It works great for parts that require large amounts of heat to remove.

I edit my love making time down to under a minute. Works for me.

Nice repair..👍 i have done an attempt to repair a hdmi fault on an onkyo receiver. It still doesn’t work but. The new chip is not smoking like the original one. But soldering that small stuff is a challenge.

Love the short version better most of us watching your great video have some good electronic knowledge and we are here to learn more from a great man than you 👍👏👏

The LSR is the old version, the new ones has scrapped the LSR and for example the successor to this one is 308p mkII.

i'm gonna remember that leg cutting method, looks easy and clean.

Very surprised about that hiss at the end. After seeing the measurement of the two supply voltages (at 07:08 showing 3.300V and 5.000V, so exact) I would expect a silent design. Maybe another fault ? B.t.w., I saw Fran Blanche with an EEVBlog multimeter, now I wonder.

Boy, that power amp datasheet is terrible! That pin description table should show the active state of the RESET pin. And the operation of the INT_LINE output is not described anywhere at all. Maybe in a User Guide? Couldn't find one on the ST website 😖

Not sure how I feel about the digital processing bits, I quite like analogue but that board is lovely, clearly marked connectors, SWIM port for programming the CPU, serial port on the flat flex socket, it looks like it'd be fun to hack on.

Thanks mate love the repair videos

Amazing how efficient Class D Amps are

Wow, the +5 volt line was spot on! 5.000! 😊

watched the full vid on EEVblog2... but thumbs up here too!

Heatsink dissipation of aluminium heatsink is 0.05 vs 0.85 for anodized one

@EEVblog2 thanks for this detailed video. I do have one issue with this same model; it has a very low volume output even at maximum volume on the knob. What could possibly cause this? Thanks in advance

What's the white goop all over the caps? Has Emma Thompson been here? How about the edge of the board ...

very nice Dave

I'm guessing they used an ADC+DSP because the previous LSR4 series were DSP-based and because the new waveguide requires too complex of filtering to be practical in analog.

Thanks for tearing those apart! They're fairly cheap so that probably explains the usage of DSPs .. I wonder if all speakers of that price range use them?

Maybe just resoldering the IC does the job. Those class D amplifiers come with a bunch of auto diagnostics and internal protection. I don't think it will blow the internal mosfets because it checks for load impedance, voltage rails, etc.

Regarding the ADC: It is much cheaper to build a crossover in software than in the analog domain. The EQ and phase response curves you can obtain in the digital world would be incredibly hard and expensive to achieve in the analog world. Regarding the quality: this is an entry level home studio speaker.

Learned a lot. Thanks

My guess - Motional feedback, where the speaker is equipped with an accelerometer ? (I haven't watched the full video yet - just a guess)

Dave sure goes through his fair share of monitors

Yes, I think it's a good idea to edit the video a little.

Where is the flux at 😳😂 Thanks for sharing Dave

love to hear your videos...... but solder, you need a upgrade ..kkkkkkkk never the less job done :)

Damn he's so smart

Solder paste now thats what i need

really great video ! Thank's

That's a bad ass looking speakers i love tweeters to

Hi EEVblog, thanks for this detailed repair work. I have a pair of this LSR308, with a very low volume output even at the maximum volume at the pod. I have checked all the voltage output as you demonstrated and everything looks good. The pod turns smoothly but I am not sure if it is working properly. Could you kindly offer any suggestions on this issue? Thank you.

Nice,.. Hope to see some waveform output of the main amplifier.

His voice like my grandma 😊

This combination ADC to some DSP+ClassD is common in extremely cheap products (that somehow want to look premium) this DSP+amp chips have really bad reputation for failure.

I first thought it was 'My Mate Vince' he'd done that in his last repair video too. ;)

I'm guessing that the digital sampling and filtering allows them to effectively calibrate the response of the speaker for variances in assembly. Probably means less precision needed elsewhere re: ABS front panel, etc...

Nice repair video 👍

Ok, who else cringed when he pulled off the pad? And also, who else has done this? (raises hand). I was surprised you didn't use hot air/rework tool to start but hey, it still works! Solder, its not just for breakfast!

Dave, Instead of cutting the pins with a big risk of pad damage, use a special low temp solder, e.g. SMD Removal Kit from Chip Quik, model SMD1NL (Farnell code: 1850218). This stuff is like magic.

12:54 - Promo for EEVblog #1323- Phone REPAIR

Same thing for the marshall stanmore/woburn speakers. Highly disrecommended.

Hi Dave i've been waiting for a video of this kind, about fixing monitors, to sugest you something: Maybe you have heard about it, it's the infamous Logitech z333 fake tweeter thing. I got them as a birthday gift and since then i've been trying to figure out a way to install a small crossover and a pair of real tweeters on them. They sound really lackluster on higs as they are right now. I don't have the necessary knowledge to decide which crossover or tweeter pair would be the appropiate. I wouldn't mind sending my z333 but i guess shipping costs from Spain to Aus are gona be prohibitive for my economy right now.....since the covid hit i am unemployed and things are looking bad around here. If you could take a look at the problem it would be great for many of us who have them, either got them as a gift or bought them unknowingly of logitech's lack of scruples. TYVM.

Nice!Vegas Pro!