Is this how Neumann KH80 speakers die?

[dasherzx]

darn. i have 4 of these near the ceiling and curtains. got them used and overseas too. on a scale of cooked/10 guess i should mount orbit11s up there next

 

[Breeze98]

There is no valid excuse from Neumann for using such awful caps

Andreas Sennheiser is not available for comment -)

 

[paudio]

Andreas Sennheiser is not available for comment -)

They probably didn't even choose them. Probably just bill of materials and price. Neumann should be putting good caps in there for sure but likely just something that was contracted out. Lack of attention to detail there.

Similar to RME rack units having good quality caps but off the shelf awful power supplies with awful caps that always fail. I repair them.

 

[paudio]

Just ordered a for parts KH80 but looks like this one works. Just has a input padding issue.

 

[paudio]

Got a KH 80 off of Reverb listed as is. Had an issue where it was 15db or so quieter than it should be. Bought a used working one. Factory reset the unit and then measured in REW confirming the issue. Tested the XLR inputs and one pin to the other two was open. Unlike the other speaker. Took both units apart and the pin in question had no continuity to the mainboard. Sucked the solder out and you can clearly see that the pin is bent and not in the through hole. Some flux and a chunk of resistor leg and got it connected without having to remove the whole module. Remeasured in REW and looking good. These units are pretty cheaply made. Screws just screw into plastic. One of the two bottom screws that wedge the enclosure to seal it is stripped/cracked. So I am repairing that as well. Cheap capacitors just like shown in this thread.

 

[kyuu]

What is the reasoning for putting that goop (RTV silicone?) all over the PCB?

 

[dfuller]

What is the reasoning for putting that goop (RTV silicone?) all over the PCB?

It squelches vibrations. With big heavy parts like electrolytic caps that can cause mechanical failure of solder joints down the line.

 

[JoeDiMEG]

These units are pretty cheaply made. Screws just screw into plastic. One of the two bottom screws that wedge the enclosure to seal it is stripped/cracked. So I am repairing that as well. Cheap capacitors just like shown in this thread.

Sad to see. The name Neumann does not deserve this. And also no customer.

KR

 

[kyuu]

It squelches vibrations. With big heavy parts like electrolytic caps that can cause mechanical failure of solder joints down the line.

Ah, I see. Makes sense for active speakers then.

 

[respice finem]

Ah, I see. Makes sense for active speakers then.

What would IMHO make more sense - an external amp+radiator module, without the "gunk" on the PCB. Some do this, like Genelec in their recent top models.
Bonus: In case of electronics failure, it might suffice to send in this module, instead of the whole speaker.

 

[Chr1]

I agree. Wish this was standard practice with studio monitors. (Reckon it's more about appearances and keeping everything compact with the smaller models unfortunately.)
I have KH310s and am hoping that the build quality is better. I think that their reliability record indicates that it is thankfully.

 

[markstein]

It would be interesting to know where the line between "junk" and "serious/professional" Neumann loudspeakers goes.

KH120II?
KH150?
KH310 and KH420 are clearly good quality.

Let's be honest: If the market asks for inexpensive products with high performance (means high R&D effort), of course the BOM cost needs to be as low as possible.

 

[paudio]

It would be interesting to know where the line between "junk" and "serious/professional" Neumann loudspeakers goes.

KH120II?
KH150?
KH310 and KH420 are clearly good quality.

Let's be honest: If the market asks for inexpensive products with high performance (means high R&D effort), of course the BOM cost needs to be as low as possible.

My K&M O410 were about the same retail price as the KH 420. I know money sure doesn't goes as far now compared to when the O410 was released. Though at $7500 CAD there ought to be some budget still for proper cabinets, capacitors, etc. These KH 80 sure seem cheap. I suppose part of it is making it light but I don't buy that at all. The wedge design for sealing the cabinet is super iffy. I had to mess with my second used unit a ton to just get it to actually seal. I had to drill out the main enclosure threads and put in some brass heatserts and switch the bolts to make the second one seal.

After fixing the sealing issue I took apart the one that had the bent leg and desoldered the entire Kean input module, unbent the leg and resoldered it in. Added some hot glue as well for mechanical mounting.

It would be nice if these were made better. Not sure what kind of margins on these. Clever design with the 2 screws only to seal the enclosure using wedging. Though not giving it metal threads and using plastic pieces that wedge into the case seems crazy. They do sound good though. I was thinking about downgrading from O410 + 2x810 to something for my currently quite small bedroom (yes) but having to repair both of these I am feeling really turned off about the insides.

 

[JoeDiMEG]

The KH120II and KH80 are ... :-(

BTW: Both are to my knowledge produced in different countries.

The wedge design for sealing the cabinet is super iffy.

I had to drill out the main enclosure threads and put in some brass heatserts and switch the bolts to make the second one seal.

Though not giving it metal threads and using plastic pieces that wedge into the case seems crazy.

I am feeling really turned off about the insides.

Thank you for your work!

KR

 

[dfuller]

My K&M O410 were about the same retail price as the KH 420. I know money sure doesn't goes as far now compared to when the O410 was released. Though at $7500 CAD there ought to be some budget still for proper cabinets, capacitors, etc. These KH 80 sure seem cheap. I suppose part of it is making it light but I don't buy that at all. The wedge design for sealing the cabinet is super iffy. I had to mess with my second used unit a ton to just get it to actually seal. I had to drill out the main enclosure threads and put in some brass heatserts and switch the bolts to make the second one seal.

After fixing the sealing issue I took apart the one that had the bent leg and desoldered the entire Kean input module, unbent the leg and resoldered it in. Added some hot glue as well for mechanical mounting.

It would be nice if these were made better. Not sure what kind of margins on these. Clever design with the 2 screws only to seal the enclosure using wedging. Though not giving it metal threads and using plastic pieces that wedge into the case seems crazy. They do sound good though. I was thinking about downgrading from O410 + 2x810 to something for my currently quite small bedroom (yes) but having to repair both of these I am feeling really turned off about the insides.

AFAIK the 310 and 420 are using higher grade parts, I know for a fact the 310s I used to own were all Japanese save for the main bulk cap on the primary side of the SMPS which was Yageo branded (a higher quality Taiwanese brand). I have yet to pop a plate amp off my 420s to see what's in them, but maybe I'll do that at some point.

 

[paudio]

AFAIK the 310 and 420 are using higher grade parts, I know for a fact the 310s I used to own were all Japanese save for the main bulk cap on the primary side of the SMPS which was Yageo branded (a higher quality Taiwanese brand). I have yet to pop a plate amp off my 420s to see what's in them, but maybe I'll do that at some point.

Ya. Maybe my post seemed like I was assuming they weren't but I meant the opposite.