M-Audio Studio Monitor Speaker Repair
HTML-код
- Опубликовано: 5 авг 2024
- Subscribe to the channel: / @allthingsoneplace
In this video we look at some M-Audio AV40 studio monitor speakers that have developed a humming/buzzing noise. Because they are used to mix audio and video editing, that could spell the end of these units.
But instead, I take them apart to see what went wrong with the AB class audio amplifier and attempt to repair the speakers by replacing the deformed and failed capacitors. This is a common failure point for powered speakers but sometimes can be repaired with a little soldering for a lot less than replacing the whole unit.
Beyond Hive Park: / @hivepark6844
Loudspeaker Repair: • Brüel and Kjær Type 42...
Tester: • Multi-function Tester ...
Timestamps:
00:00 Introduction
01:00 Examine the Internals
05:28 Repair Time
07:00 Cap Tests
09:40 Power Tests
Equipment:
Video Editing Software: Davinci Resolve 17
Video Camera / Still Camera: Sony ZV1
Lights: Three VILTROX VL-200T
Microphone: Rode SmartLav+
VARIOUS LAB EQUIPMENT
Website: www.allthingsoneplace.com
#maudio
#righttorepair
#soldering
#pcbrepair
Updated: 24/9/2021 11:45
Video: 57 
Наука
Thanks for the help, nice to have the monitors back and buzz-free 🐝
It was a fun project, glad they are working for you.
The two gray wires can be unplugged, along with the woofer and tweeter wires to remove the entire back assembly. The circuit board can be removed from the back panel as well. I bought a dead one of these just to get the tweeter, but now I'm repairing the board by recapping it. So I'll have a spare amp assembly! Thanks for sharing all your work.
I wonder how often the actual amp chips fail, I guess if the caps get bad enough the amp might fail too.
Thank you, this was really interesting to watch. I once repaired my Mackie CR4 speakers. It was also a faulty capacitor that made the speakers go mute all the time, and I also introduced a LM7812/LM7912 combo board for +/-12V instead of the original design which made the PCB burn. Now they work flawlessly, the PCB no longer heats up, still alive and kicking.
I have seen poor regulator design with a giant resistor next to a capacitor in so many speakers and the heat causes the ultimate failure of the board. All in the name of built down to a price. These M-Audios and the bend over leads... I know vibration, but that doesn't matter if the caps overheat so much they turn into crisps.
@@AllThingsOnePlace yes, and judging by the video, I think those M40 speakers also utilize two 12V zener diodes with one big resistor per each and a cap to stabilize the voltage. But the zeners usually cook those caps (and yours were bulging, too) and burn the PCB in that area.
That area on the M40s is all the way up, so the heat can instantly go upwards. On the CR4s, it is closer to the TDA7265 amplifier heatsink and just under the transformer, so it is already in the hot area and obstructed by the components above it, making the heat accumulate more easily and damage the PCB.
Nice video, glad to see these could be repaired and saved from the landfill
Saved for another day.
I have these exact same speakers that have been exhibiting this buzz since 2016. I’ve been dragging them with me in a box thinking I’d get around to taking them apart and fixing them so thank you for giving me the information I needed to do this weekend project. I bought them in 2007 and they performed awesome until the buzz. I wonder why M-Audio uses a cheap capacitor for these premium monitors.
Yeah, it is unfortunate. It is ultimately the demise of many electronics products today.
wonderful video. I know its months ago, but its great.
Thanks for watching! Yeah, this video is a 'sleeper', gets more views now than it did when it came out.
Thanks. I recapped mine because the amp was distorted, but last night it started the buzzing thing. I recapped them with all Japanese caps, but maybe I only replaced the bulging ones. So I guess I'm going to take it apart and recap everything again
Yeah, it's like hardly worth the effort but at the same time it keeps them going. I'd like to see more of these small speakers switch to class D amps but also just not cheap out quite as much or make them more repairable.
Awesome video, thx for sharing!! 🎉 Got same model, and same problem... Hope I'll find the issue
Good luck!
its mine.using 8 years and im happy.only some repair of cables and one socket repair
Nice! Yeah, I'd say the biggest thing is turning them off when not in use. Less wear and tear on the capacitors will mean a longer service life.
Amazing... Thanks a lot
Thanks for watching. They're still going.
Thanks so much for your video . I am working on a broken focal twin 6be .
Did you show in the video how you discharged the caps before working on them ? Or is that not necessar ?
Kind regards
I just checked them with a multimeter. By the time you unplug everything and disassemble it they should be at zero volts. I don't know the particulars of the power supply in that unit but if needed I use the low-z setting on my Fluke multimeter to discharge caps, probably not the best option but it's worked for me.
Hi there, i got a question. I have a pair of tascam studio monitors, bit one recently didnt produce any sound. I thought/hoped it would just be a cabel problem. But whenever i turn off the on en off switch off at the end i hear some music again, but when i turn it on again no sound come out. Have any idea what the problem might be? Thx in advance
It sounds like the circuit is deciding to mute the output. The amplifier IC's usually have a MUTE pin connected to some kind of logic for various reasons and during the ON mode it sounds like that is being enabled. During power down it briefly lets the amplifier turn on. This could be from several different causes inside the speaker. It would require some investigation of the circuit board to find the problem. If the issue is purely cosmetic (meaning a bad logic decision and not overheating or power supply issues then the logic could be replaced to solve the problem). If it is being kept off due to a bad power supply rail then it could be the same issue as with this M-Audio speaker.
@@AllThingsOnePlace thx for the explanation, hope my mate will be able to fix the problem. Bless
I've been having some problems with the AV-42's recently (very very similar to this pair)
They have no power of their own for some reason.
When plugged in and sending signal through an RCA from a pre-amp then sound plays fine, but the power light on the speaker isn't showing, and using the aux input doesn't work at all
Any suggestions?
That sounds like more of a loose or broken wire issue (inside the speaker I mean) if some inputs work and others don't. No power light is also concerning but seeing how that is on a remote board also in a lot of these I wonder if the connections got jostled enough to break. Just a shot in the dark on that one. If you don't know the insides of these thing it may be more risk opening it though if one of the inputs works, use it.
Years ago I made a video on repairing some BX5a & a couple days ago I just replaced the caps again but I still got a crackle so last night I re-capped the whole board except for the 1 NP cap on the MB & the 2 NP caps on the daughter board. My driver works but the tweeter now cuts out & then comes back on. Any ideas? Like maybe the 2 transistors are starting to go?
Hmm, if it is a passive crossover (single power amp, not bi-amped) it is probably a bad solder joint or loose connector/wire. If it is bi-amped, which it looks like it is, then the amplifier chip for the high side could be on the way out. Based on cutting in and out but works fully when it is on then I still lean towards a loose connection or bad solder joint.
@@AllThingsOnePlace Thanks for the reply. I much appreciate it! I'll have to go over everything again. I didn't see anything. I never had a amplifier chip go on me. If that's the case I hope I can get one.
SOMETIMES MY IMG stageline FLAT M100 just works. Whether I adjust the volume knob hard or soft. And the next day it does nothing, only when I adjust it louder. But the sound that comes out is very poor. Very strange. Do you know what the options are?
I'd start with getting some contact cleaner and spraying the adjustment knobs. Deoxit or something similar. You probably still have to disassemble to get to the area that will make the cleaner effective.
So I plugged the speaker wire into the back of the left speaker and when I did that, the clip that you push back and put the wire in, that clip fell off, is it an easy fix? It still works as long as I can keep the speaker wire in that port and they sound great..Can I use electricians tape to hold it in place? I did buy them through reverb used and I just tried hooking them up today, so except for that clip falling off they sound great.
Mmm. Yeah. I’ve had that happen to lots of other speaker clips. I think the temporary fix might have to be it if you don’t want to buy a new connectors and do some soldering.
My M-Audio started SCREECHING like an alarm. I turned the volume knob down all the way, still screeching. Pulled the cables and wires, still screeching. Could this effect be the transistors failing? I've never soldered and would like to get an iron, but I don't know if it's worth the cost and effort if it's not the same fix.
Sounds like the amplifier turned into an oscillator. The power transistors haven't failed yet if it's making noise but something else certainly has. I would start with inspecting the capacitors. Being a signal issue it might not be the main power capacitors but the smaller signal ones which there are a lot of and may put this in the beyond economic repair category. If it is a project to learn though, it is not a bad idea to spend some trying to figure it out.
Thanks sir for sharing your knowledge with us.
Apart from capacitor is there any other components that causes humming sound
Yes, there are other ways humming can be introduced. Anywhere a ground loop can be created or some loose connections inside or outside the loudspeaker amplifier can also create humming. In general when the amplifiers fail you usually get silence though so hopefully not that condition.
@@AllThingsOnePlace Thanks alot for giving me such informative reply
I have the same issue but my caps are not bulging, could they still be bad? Also what is the reason for using different spec caps for the replacement? Thanks!
The capacitors could still be bad. I just used what I had on hand. Ideally getting a similar rated capacitor would be best but I did a quick check on energy requirements and found that was good enough for moderate volume playback. Full volume the caps I put in are too small.
@@AllThingsOnePlace Thanks for the quick response! I don't have large caps so I'll order identical replacement and we'll see.
hi sir,i have the m-audio studio monitor speakers,same like on this video
so my speakers problem is,the right speaker is louder than the left one
,so what can i do to make it balanced sir.thankyou
Hmm, that is good question. During my repair I didn't see any potentiometers for tuning the balance of the loudspeaker. It may have something under some of the other components but that might be more work than it is worth getting to it. A possible solution is to get an exact measurement of the difference between the left and right sides and add a passive resistor attenuator on the input cable with a resistor divider to bring the output back into balance. Another quick check is making sure the wire connecting between the two speakers isn't frayed or missing most of the strands. To make sure it isn't a cable or source issue you can swap the left/right RCA inputs and make sure the attenuation doesn't change speakers. If it does then the source is the problem not the speakers. A passive attenuator can be purchased ready made www.markertek.com/product/ses-rca-lvl-lr/sescom-rca-lvl-lr-stereo-rca-volume-control-with-independent-left-right-channel-control although this is a pretty expensive solution to this issue.
@@AllThingsOnePlace thankyou for your time to reply and give me some answer. ill try it
Hey Boss, I have the same speakers and a similar issue. I'm gonna crack the housings open and have a look inside to see if the caps have leaked. Thanks for the info I'll add replies to let you know if I fixed em.
Yeah, it's amazing how many products get ruined by such a small component in the system.
Is the crossover for the left speaker a stand alone part or is it on the board? I think I’ll convert it to passive, if I can figure that out.
The crossover is separate in each box.
@@AllThingsOnePlace Thanks! I can salvage the speakers and forget the electronics!
hi man i have the same speaker ,it was always okay until the past few days,suddenly the right speaker with power in it sound very quiet than the other one, is something happen with the speaker ?
Yeah, a few people have had that fault also in the comments section. It is a tough one to diagnose. It could be anything from a dirty potentiometer (volume knob) to a failing amplifier. The fault in this video was symmetrical in both speakers so probably not that. When it’s on one side I’m always suspicious of the wiring. If using rca connection swap the connection and if right is still quiet then the fault is in the speaker. If it swaps to left then the fault is in the cable.
Oh hey one more question about polarity. I understand the longer lead on the capacitor is the positive side. Is it obvious which pin goes into which pinhole on the circuit board?
Sometimes the manufacturer will put it on the silkscreen, sometimes they use a square and round pad in the copper layer. All up to preference. I usually give it a quick check with a multimeter to make sure the positive side goes to something that makes sense like the positive side of the bridge rectifier or the positive input on a voltage regulator or op amp.
I need one of my ex66 m audio speakers to work. It plays low while the other is loud. Can you help me
There is a whole chain of troubleshooting. I don't know your technical level so I assume beginner at first. The first step is somewhat obvious and you probably did this already but check the gain controls on the back of the monitor and make sure they are the same (as well as all the other settings). I noticed these have a voltage selector on the back too so another thing to check. The next step is to swap the input cables between the two monitors (at the monitor, not at the source). If the other speaker plays low now the problem is elsewhere (cable, mixer, etc.). Okay, eliminating a gain or a source problem the monitor speakers likely have some internal adjustments or components have drifted and after years of use something could have shaken loose or changed in value enough to cause some degradation. It is highly unusual for a power amplifier to go quiet. Amplifiers usually get noisy, make tones, oscillate, go silent, pop, but just getting a little quieter is not a normal amplifier failure mode. So, if there are any other symptoms those may be a clue to the issue. The next step is opening it up (at your own risk, remember mains voltage is present inside) and checking components (in circuit as much as you can) and doing a visual inspection. The next rule is check voltages. You have a known good to check against so that helps since the schematic isn't available. If you don't know the electronics then repair shop. If you do then there's a lot to do!
What was the little jumper wire you added? that wasn't there originally was it?
No it wasn't originally there, when removing the old capacitor with it's bent over leads it pulled the pad off of the PCB.
Gotcha. Thanks.
Hi, I have changed these 2 capacitors but still have the same problem (buzz when I torn on). Do you know any other parts that can do that ?
Depending on how far down the rabbit hole you want to go, there are more capacitors that can fail on the circuit that will induce hum. I'd get an in circuit LCR meter to check the others and replace the others that also test poorly. Buzzing specifically can also be from ground loops or loose cables.
@@AllThingsOnePlace thanks, I just realize that fuse 1 is blown, I changed it and blowns again.
@@idlmAh, yeah. Sounds like there's a short circuit somewhere. A thermal camera is pretty useful or a milliohm meter if you have one. Or, inject a low voltage and probe around until you find the trouble spot. Check any capacitors for a short circuit. Hopefully, it isn't the chip that's gone bad.
Hi, I appreciate the video. I have m-Audio BX8a deluxe monitors. One of the woofers plays at a very low volume while the tweeter plays at a normal volume. I switched out the woofers and they aren’t the problem. Any ideas? I haven’t been able to find anyone with the same exact problem. Thank you
That could be a simple one, there is probably a small analog adjustment on the amplifier circuit board (potentiometer), it may have come unglued and moved a little inside the cabinet. This could lower the volume or raise the volume of one piece of the equipment. This is pretty rare but it can happen. Because it isn't a total loss of sound, and the rest of the system is working, it seems more likely, also assuming the sound is still clear but it is just quiet. There may also be crossover settings on the back of the speaker. I assume they and any potential wiring issues have all been checked first before opening or swapping anything. Anyway, opening or doing any work on or near the circuit board is certainly a more risky operation so always be safe and that is at your own risk.
@@AllThingsOnePlace alright great, thank you for your response. I might look into that in the future but you gave me a great idea in one of your other comments. I hadn’t considered turning them into passive speakers. I've replace some caps previously and the monitors are pretty noisy(buzzy) in addtion to one of the woofers playing at an extremely low volume. It seems like the amps in M-Audio monitors are very unreliable.
I have some Hertz Mille Pro passive crossovers meant for 2 way component speakers in a car and I dug out an old Kenwood KR-V87R receiver.
It sounds really good. I even measured the speakers with a umik-1, rew and pn pink noise to see if the crossover was working as intended and it measures very well above 40 hz. Thanks!
@@Titans2138 Ah ha, yes, that is a great idea!
@@AllThingsOnePlace Thank you! Like you, I'm sure, fixing things is very satisfying and figuring out this unique solution feels just as good.
I have the M-Audio Bx8 D2….. I’ve been searching for hours and this is the closet I’ve found. Hopefully someone can point me in the right direction.
My 1/4” TRS input was damaged. It’s still kinda works but I just need to know how to replace this part. Thank you!
Take it apart, desolder the bad connector, buy a new one and solder it in, reassemble. 1/4" connectors fail all the time, I keep a pile of them in stock. If you can't do that yourself that is fine, find a repair shop, it may be a ways away, they should be able to do that for not a lot of money. The part is only a dollar or so, labor should be less than 2 hours. You need to find someone local since shipping will make it beyond economical repair.
It’s normal the one with amplifier gets to hot ??? Any advice ?
How hot is hot? It is normal for a class AB amplifier to get warm, almost hot, if it is too hot to touch then it probably means some components have drifted in value and it is being biased on too much or trying to feed DC into the amplifier somehow. This causes extra heating and eventually will lead to the failure of the amplifier. It could be normal though, if the speakers are operating, when you turn them on you don't see any static speaker cone deflection or unusual noises it is probably fine for at least a little while longer.
Hi, this is awesome, but I don't have the tools that you've got for repair. I would LOVE to not toss our speakers. Even though I'm pretty sure I could manage the mechanics of repair, I'd have to buy all the stuff to accomplish it. Do you do repairs? I'm guessing no, but if yes, I'd love to hear back!
For the sake of making a video, I did this one. This really falls into the beyond economic repair category, just shipping these will cost more than a replacement. High end gear generally makes it worthwhile to repair. Event Precision 8 are an example there. There are companies that specifically repair that speaker. So, anyway, no I don't have a repair business.
How is it happened that the PCB pad was missing?
The way they manufactured it with the bent over legs on the components it pulled the pad up with it on removal.
How much would a repair like this cost if I brought it to a shop? Great video
The parts were less than $10, it should take less than an hour to do this repair but the issue is one hour of labor and $10 of parts is probably more than buying a new set.
i have those.. but the left speaker lost power.. it sounds muddy and like half its volumen
Hmm. That sounds like it could be as simple as cleaning the volume potentiometer. But as a proof of not the input, swap the input cables around to make sure the bad audio doesn't swap sides. Eliminate the cable and source as the problem. The amplifiers can go bad though, and it is possible that a difference capacitor has failed within the amplifier unit causing one side to attenuate and change frequency response.
Possible to bypass everything and straight to speakers like the other monitor?
Yes.
How does the speaker that you opened compared to the other speaker without the volume control look like?
@@VanThieu You know I never opened the other one so no idea!
What is this music on 5:40?
When Johnny comes marching home. It’s called pick something from the RUclips library I recognized… also in die hard 3.
mine gets super hot a the back how to fix this issue
I am not sure. These use class AB power amplifiers so they do get hot but there is a point that it is excessive. As the operating point drifts on the amplifier it may be slowly going more class A which means getting hotter. As that happens the amplifier will thermally run away at some point and shutdown or break. This was notorious for happening with the Event Precision 8's. These M-Audio's are made with the right components but certainly not made to last a long time.
Does anyone here have an idea why my monitors sound is uneven? These are powered monitors and one side is louder than the other and if I switch the position select from left to right or viceversa one side still will be louder. It has a damaged capacitor or a resistance or what is could be the problem?
There are potentiometers inside the monitor that adjust gain for each, these aren't really user serviceable and are glued into place. So, as long as both are working, it doesn't sound like damage but a gain adjustment that has shifted.
I have one that just doesn’t work at all same unit
Yeah, that will require much more work. It is likely the amplifier chip itself has gone bad. I would expect the capacitors to be bad as well. This can always be repaired but it gets to borderline beyond economical repair.. I would actually recommend converting the powered speaker into a passive one and getting a small external amplifier. Time wise it will be much cheaper.
че за музон?
Standard system greeting.
So long story short.... I should be turning off my studio monitors after every use....?
Yes.
🙏🙏🥳🥳💖💖💖🤗😀😆😆😛👍👍🥰🥰🥰🥰🥰🎁🎁🎁💖💖💖💖💖💖💖🤗
Yes
😆😆😀😛👍🥰🥰🤗🤗🤗💖💖💖💖💖💖💖💖💖💖💖💖💖💖💖💖
Okay
That was Greek. 😂 I’ll figure it out
Yeah, I can’t know the skill level I guess. Worst case take a photo of how they are and put them back the same way.
👍🏻
Thank you
Great video! 🙌🏼
I have the same pair but the next generation but my problem is that when powered on the light comes on but neither speaker produces sound except the headphone jack. I’ve opened them once before but didn’t find any obvious faults would you be able to point me to where it may be? Thanks
That could be two things. 1, the headphone jack actually lifts the signal to the amplifier and is stuck in the open position, so even with nothing plugged in it never reconnects the amplifier. 2, the amplifier chip itself has failed and is stuck in a protect mode so won't make any sound. Obviously one of those is more of a visual inspection but probably not the issue, the 2nd is much more involved and is probably it.
I bought 2 sets of these and they both tanked with relatively short use . I can`t do the fix so what would it cost at a repair shop ? M-audio should use better capacitors in the first place . Will never buy anything from the again cuz they suck !
I agree with you on the quality front. Bending the pins over on the caps is an especially mean trick, takes a one hour job and turns it into a four hour job. It's probably well over a hundred dollars to take this to a repair shop (if you can even find one). Which means not worth it. Another option is make both speakers passive and use a small external amplifier.