Beolab 28 power cords/buzzing

[checkler]

I have just purchased and installed a pair of Beolab 28’s. As each speaker is no more than three inches from a power outlet on the floor, the power cord that comes with each 28 is rather long. Is there anything special about the power cord that the speakers come with? Is it okay to switch out a 3 foot cord for each speaker as long as both ends look the same as the original longer ones?

Secondly, although not particularly annoying, the Lab 28’s are connected to an LG9 television by a B&O core that is located behind the television. When the previous Lab 20’s were connected to the tv via Core, there was no humming sound when adjusting the volume. With the 28’s there is a subtle humming sound when adjusting the volume. This humming does not occur when just streaming music or radio.  Any imput or recommendations would be appreciated.

 

[Curly]

Totally off topic and I apologize but  I’d love to hear your impression of BL28 vs. BL20…

[checkler]

Curly,

Although I have only lived with the Lab 28’s for a couple of days, I have absolutely no regrets about their purchase. I researched carefully and listened to the speakers in two B&O stores before the final decision to buy them. The 28’s replaced the 20’s which have been placed elsewhere in the house where 9’s used to be. It has always been difficult for me to answer the question, “How do the newer speakers compare to the older ones”?, but I will try. – The 9’s remain one of my favorites which were my first three way B&O loudspeakers. The 20’s always seemed to have a more “crisp” sound to me with a less “boomie” sound on the bass side, but the 9’s still seem to deliver a more rich and full sound.  I guess the best way for me to describe the new 28’s is that they seem to represent a more realistic and natural sound than both the 9’s and 2o’s. Unlike the 20’s, 9’s, 12-2’s and 8000’s that I have, I find absolutely no reason to adjust the bass or treble on the 28’s.

[svendsen991]

Hi Checkler

Yes it’s okay to replace your power cords for the Beolab 28. It has its own power supply built in.

About the humming on volume change. I assume you have connected the 28’s over powerlink? I have experienced it when i used the wrong cable on the 28’s and 17’s. You need a good shielded cable that’s verified by your local B&O dealer/cable pusher or (if I remember correctly) an Ethernet cable CAT 7 also has the desired shielding that can get the job done. I found out that the shield works as signal ground and weird things happen when you don’t have a common ground.

Hope it helps solving your humming problem

[checkler]

Thank you for responding to my question regarding the 28’s. My B&O seller has sent me new and shorter ethernet cables for powerlink connection and has advised me for shorter 1 meter mains which have already been purchased. The next step is to figure out how to best remove and replace the wooden curtains before replacing these cables. Thank you again!

 

[matador]

checkler wrote:

has advised me for shorter 1 meter mains which have already been purchased.

Be sure they are labelled “audiophile power cord” to enjoy the full 28 experience!
(Dillen if you read us…)

 

 

 

 

 

 

 

 

(Of course a joke…)

[trackbeo]

Consider using the Core’s optical output to the Beolab 28’s combi-optical/analog input?  (Steve @SoundsHeavenly assures us that the Core can do variable volume out over the optical.  See: https://forum.beoworld.org/forums/topic/beosound-core-beolab-18-connection/  )

It’s a cheap & easy thing to try while you wait for your Powerlink cables to be delivered. A high-quality optical splitter is important (because the Core only has 1 TOSlink output & 28s do not have optical “thru” to the other speaker), but the TOSlink-to-3.5mm optical cables are cheap.  (Don’t use 3.5mm optical “adapters”, get one-piece cables; too much light loss/reflection otherwise, especially with a splitter inbetween.)

It might even sound better!  Certainly it will sound different.  Powerlink, being analog line-level audio, is susceptible to electrical noise, as you have discovered.  Plus you’re doing a D/A conversion inside the Core (to transmit the digital source or broadcast audio over analog cables) and then an A/D conversion inside the 28s (to perform the sound correction/EQ/etc.).  Even given the highest quality converters, it seems pointless.  [Insert equally-pointless argument here about effectively reducing audio resolution bit-depth, by doing volume control in the digital domain.  Just *try* it!!!]

P.S.  What’s dumber than a $5000 Audioquest “Perfect-Surface-Silver” power cord?  Gold-plated connector shields on a plastic or glass optical cable…

[Author]

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