Is this normal?

[Rabepobemababe]

Yesterday, I took home my new acquisition, a brand new NAD C-426 AM/FM tuner, from VECTOR, Banjara Hills, Hyderabad (thanks to all those courteous folks at VECTOR!!!). I connected it to my existing component setup, and it sounded indeed very clean with just the supplied wire-dipole, indoor antenna (no external Yagi, Quad, Dipole or Whip). However, I observed that the left channel volume is always slightly lower than the right one. Also, the left channel is mostly treble dominated, while the bass is concentrated in the right one. I tuned into different Hyderabad based FM stations, and experimented with different interconnects, with the same results. The observation held good every time. This is a bit strange to me!

When I searched online, I found out that the "left channel low" problem is a commonly perceived one with the FM receivers of different brands.

Now, I am guessing that this has something to do with imperfections (either at the station level, or at the tuner level) in the addition-deletion process that the FM Stereo transmission employs. From Wikipedia:

"...It is important that stereo broadcasts should be compatible with mono receivers. For this reason, the left (L) and right (R) channels are algebraically encoded into sum (L+R) and difference (L?R) signals. A mono receiver will use just the L+R signal so the listener will hear both channels in the single loudspeaker. A stereo receiver will add the difference signal to the sum signal to recover the left channel, and subtract the difference signal from the sum to recover the right channel..."

Is my guess correct? Has this phenomenon ever been observed by the distinguished members of this forum? Or is it that my brand new tuner has some flaw?

 

[omishra]

No, I never observed this. Whatever you read is correct but you can misinterpret the same.

It is true that Stereo transmission contains (L+R), (L-R) and 19KHz pilot.

Mono receiver do not recognize pilot and puts (L+R) in output. (be mixed/same audio in both channels)

Stereo receiver will recognize that pilot and produce 2X19KHz = 38KHz in phase carrier. This will be used to decode that L and R separate by stereo decoder as follows -

[ (L+R) + (L-R) ] / 2 = 2L/2 = L

[ (L+R) - (L-R) ] / 2 = 2R/2 = R

So nothing getting lost here and FM station equipments are far far better than receiving ends. So most of the problems are here at receiving end only.

 

[reubensm]

I use the NAD 402, one of the all time greats (Best in the world - 1994) and after seeing your post, I put on the earphones and listened to all our local FM stations for about 10 minutes each. Could not notice any difference in performance from the left channel. Both were perfect. Transmission was in perfect stereo. Of course, its really bliss, listening to the 402 on my floor standers.

However, I must tell you that my brother once tried out a Marantz tuner and had a simlar problem. He returned it to the seller and got himself a NAD 416 which is the successor to the 402.

 

[prankey]

Get it replaced unless some settings are messed up (or cabling or speakers - swap them to confirm). I used to have similar issues on my Phillips 2in1 and I also got into this placebo that its "normal"

 

[reubensm]

Yes, agree with Prankey. You need to check the following:

1) Are you receiving strong signals from your local FM radio stations (not too much of a concern as NAD tuners are very sensitive)? Have you tried an external antenna?

2) Did you check for electrical interference and cabling issues?

If both the above dont exist, suggest you return the tuner you got and get another piece. NAD tuners are usually the best probably in their class.

 

[sam9s]

***Off topic*** what on earth does "Rabepobemababe" relate to and how am I suppose to pronounce it ... ..... ****Off topic end****

 

[omishra]

Get it replaced unless some settings are messed up (or cabling or speakers - swap them to confirm). I used to have similar issues on my Phillips 2in1 and I also got into this placebo that its "normal"

In my case this happened after new furniture in bedroom. That changed speaker setting for left speaker which as 1 meter away from side wall. Now 12" away from furniture door. So that speaker sounds little brighter than right. I testing will all swapping including swapping the input, out of amp, speakers itself. That's there from onwards unless I move speaker away.

 

[gobble]

Yesterday, I took home my new acquisition, a brand new NAD C-426 AM/FM tuner, from VECTOR, Banjara Hills, Hyderabad (thanks to all those courteous folks at VECTOR!!!). I connected it to my existing component setup, and it sounded indeed very clean with just the supplied wire-dipole, indoor antenna (no external Yagi, Quad, Dipole or Whip). However, I observed that the left channel volume is always slightly lower than the right one. Also, the left channel is mostly treble dominated, while the bass is concentrated in the right one. I tuned into different Hyderabad based FM stations, and experimented with different interconnects, with the same results. The observation held good every time. This is a bit strange to me!

When I searched online, I found out that the "left channel low" problem is a commonly perceived one with the FM receivers of different brands.

Now, I am guessing that this has something to do with imperfections (either at the station level, or at the tuner level) in the addition-deletion process that the FM Stereo transmission employs. From Wikipedia:

"...It is important that stereo broadcasts should be compatible with mono receivers. For this reason, the left (L) and right (R) channels are algebraically encoded into sum (L+R) and difference (L?R) signals. A mono receiver will use just the L+R signal so the listener will hear both channels in the single loudspeaker. A stereo receiver will add the difference signal to the sum signal to recover the left channel, and subtract the difference signal from the sum to recover the right channel..."

Is my guess correct? Has this phenomenon ever been observed by the distinguished members of this forum? Or is it that my brand new tuner has some flaw?

I seem the have the same problem in my car stereo. but that may be a loose contact.

The NAD tuner looks nice - is the large dial knob for tuning channels or a volume pot?

How much did you pay for it?

Try swapping the L and R speaker cables and see if the symptoms are mirrored/swapped. This will tell you if its the room acoustics or something else.

--G0bble

 

[siva1306]

***Off topic*** what on earth does "Rabepobemababe" relate to and how am I suppose to pronounce it ... ..... ****Off topic end****

I gues it is "Come, Go, baby"

 

[Rabepobemababe]

After mounting the twin-lead dipole antenna that came with the tuner higher up at the lintel level (A wooden stack was made in DIY fashion for the "Classical Jesus Mount," and copious amounts of duct tape was used to keep the 'T' straight), the imbalance between the left and right channels has now disappeared.

Earlier, I had gobbled up the twin-lead, and packed it behind the hi-fi rack to keep the mess out of sight. I guess a properly mounted antenna is a must for decent FM reception.

There was a Telugu joke regarding the President of Zimbabwe, "Rabepobemababe" (spoof on Robert Mugabe, the then President of Zimbabwe), who once invited the "who is who" of the world for playing a death-roulette. However, there was no revolver and single bullet in this roulette. Rather, the one to die was chosen through a card-game. Much to the chagrin of the remaining participants, the fellow who was to die, was sent into an adjoining bed-room with couple of voluptuous six-footer African girls. The participants protested. Mr. Rabepobemababe smiled, and explained to them that the girls were cannibals. I took my user name from this story, the meaning of "Rabepobemababe" being what Siva has described above.

 

[reubensm]

Great to know that your tuner is fine...NADs have a reputation for making some fantastic tuners...happy listening!!

 

[theironhorse]

***Off topic*** what on earth does "Rabepobemababe" relate to and how am I suppose to pronounce it ... ..... ****Off topic end****

OT but that was my first question.. man what does that ID mean..

 

[theironhorse]

saw it later.. got it..

 

[mrunalrane]

dear o mishra,
can u pls explain in detail how does a radio decode the L & R signals for a stereo reception eager to listen to u. i did not understand in u r post
thk u
waiting for a feed back..

 

[omishra]

dear o mishra,
can u pls explain in detail how does a radio decode the L & R signals for a stereo reception eager to listen to u. i did not understand in u r post
thk u
waiting for a feed back..

Hi, Just saw your post, I was away from the base.

Please find some interesting stuff here..

Also some tips for someone like me he spends money on old stuff.

There are loads of stuff on FM antenna, I built one and using since last 2 monsoons.

 

[gobble]

Whats the price of a NAD c426? I want one now.

-G0bble

 

[canchi]

Whats the price of a NAD c426? I want one now.

-G0bble

You do realize you are biting at a thread that has been dormant for a year and a half. Let's see who gobbles up the bait