Any one with an oscilloscope?

[tillerman6]

Just curious- I was getting a big "muddy" zone in my listening area and reading all about things being out of phase and to double check my speaker wiring- (which I did 3 times) but today I decided to put my two channel oscilloscope on my left and right AMP TERMINALS. Lo and behold- the two positive red terminals on the main front left and right terminals were 180 out of phase!
(1000 hz test tone from YOU TUBE)
Is that normal? My Receiver is a Yamaha RX-V365 . I couldn't do anything about the internal wiring inside the unit, so I swapped the perfectly correct wiring on the right speaker, and it made a difference even the wife noticed! Go figure! Is this a Yamaha thing? A guy could chase his tail for a long time trying to get rid of that muddy sounding set of speakers, or even start trading them for more expensive ones whose own internal wiring MIGHT BE REVERSED AGAIN??? in which case it would point to the speakers fixing the "problem" or worse yet- endlessly swapping speakers and never getting the dead zone fixed at all!

 

[TLS Guy]

Just curious- I was getting a big "muddy" zone in my listening area and reading all about things being out of phase and to double check my speaker wiring- (which I did 3 times) but today I decided to put my two channel oscilloscope on my left and right AMP TERMINALS. Lo and behold- the two positive red terminals on the main front left and right terminals were 180 out of phase!
(1000 hz test tone from YOU TUBE)
Is that normal? My Receiver is a Yamaha RX-V365 . I couldn't do anything about the internal wiring inside the unit, so I swapped the perfectly correct wiring on the right speaker, and it made a difference even the wife noticed! Go figure! Is this a Yamaha thing? A guy could chase his tail for a long time trying to get rid of that muddy sounding set of speakers, or even start trading them for more expensive ones whose own internal wiring MIGHT BE REVERSED AGAIN??? in which case it would point to the speakers fixing the "problem" or worse yet- endlessly swapping speakers and never getting the dead zone fixed at all!

If that is true, your receiver is faulty. If you know how to read a scope it will not be lying to you. Never heard of this happening before. Can you take a photographs of the scope screen, so we can confirm this for you?

 

[tillerman6]

If that is true, your receiver is faulty. If you know how to read a scope it will not be lying to you. Never heard of this happening before. Can you take a photographs of the scope screen, so we can confirm this for you?

I thought of that, but I could not hold the test probes on the output jacks and take pictures with one hand while crawling behind the equipment stand. Trust me it's 180 out!

Just to make sure I put both probes on the calibration test point on the front of the scope and they were perfectly in phase as you would expect. Both signals are 1KHZ. the one on the scope is a square wave.

I have some new cabling and clips coming in the mail soon that will make it easier to take pictures next time.

 

[tillerman6]

I thought of that, but I could not hold the test probes on the output jacks and take pictures with one hand while crawling behind the equipment stand. Trust me it's 180 out!

Just to make sure I put both probes on the calibration test point on the front of the scope and they were perfectly in phase as you would expect. Both signals are 1KHZ. the one on the scope is a square wave.

I have some new cabling and clips coming in the mail soon that will make it easier to take pictures next time.

Did the test again after hooking up the aforementioned test leads and now the out of phase condition is gone.

I will be removing this receiver soon and I plan to investigate further. Not sure what happened, but could be a scope setting. still have a weak right channel after approx 1 hour of play time.

 

[Speedskater]

An easier way:
With a battery powered Digital Multi-Meter (DMM) that has a low voltage AC range. It does not need to be True RMS or even accurate.
Play a mono tone test track.
Measure each channel Red to Black terminal, there should be a few Volts
Measure amp's Red terminal to Red terminal, there should be about zero Volts.

 

[Hobbit]

Just curious- I was getting a big "muddy" zone in my listening area and reading all about things being out of phase and to double check my speaker wiring- (which I did 3 times) but today I decided to put my two channel oscilloscope on my left and right AMP TERMINALS. Lo and behold- the two positive red terminals on the main front left and right terminals were 180 out of phase!
(1000 hz test tone from YOU TUBE)
Is that normal? My Receiver is a Yamaha RX-V365 . I couldn't do anything about the internal wiring inside the unit, so I swapped the perfectly correct wiring on the right speaker, and it made a difference even the wife noticed! Go figure! Is this a Yamaha thing? A guy could chase his tail for a long time trying to get rid of that muddy sounding set of speakers, or even start trading them for more expensive ones whose own internal wiring MIGHT BE REVERSED AGAIN??? in which case it would point to the speakers fixing the "problem" or worse yet- endlessly swapping speakers and never getting the dead zone fixed at all!

Do you use YPAO? I have no direct experience with it. However, I accidently got the terminals mixed when wiring speakers and Audyssey caught it. It gave me a message telling me which speaker was out of phase and to swap the wires. I would think YPAO would do the same thing.

 

[tillerman6]

Thanks for the question!
But at that time, and with that receiver Yamaha RX-V365 there was no YPAO functionality available. I have had that receiver for years and it does not even have a jack for a microphone anywhere on it. So I was doing it all by trial and error. It took weeks to get it sort of normalized.

I sort of got frustrated and changed amps to a Denon AVR-S970H which I'm trying now. It has a EQ app and a micophone and I'm in the middle of getting it set up now. I ran one calibration test and it was OK, nothing to write home about. But a lot of changes were put into the mix and I did not have my new speakers installed and located where they should be. I am using two flat panel ( ceiling tiles) with the Dayton exciters glued to the backs- surprisingly, they do work fairly well, but the room has a vaulted ceiling and is about 24ft wide and 16 feet deep, so it needs a lot of help. I am using the two flat panel "speakers" hanging from the ceiling and slung down facing my seating position across the room. There are also the usual 5.1 channel surround speakers beyond that.

Overall- I'm mostly interested in the audio qualities of any system. We don't watch movies, and the wife can't stand much volume while I also have tinnitus, so it's hard for me to enjoy at any level she can tolerate.

Yes I have some headphones, but when she sits on the couch and I have the headphones on I can't hear her asking me questions or whatever, so most of the time- no headphones.

So am trying for a lower level listening experience with max intelligibility of voices in the music. And it's 90% Spotify, 5% You Tube and 5% DVD's or other CD's .

If you have any questions or comments, I am always here. I'm sure I could learn a lot.

The new receiver was a handfull to get going and some of the instructions were a bit confusing, but it's working fairly well now- not sure if it can be made simpler to operate? The HEOS and Denon apps are separate from the Spotify app and the remote for the Denon AVR-S970 is a bit rough on the volume adjustment, so it's smoother to use the HEOS app for volume adjustments- which are quite frequent because of the variability of the Spotify source, but you find yourself constantly switching from APP to APP to control everything.

 

[tillerman6]

An easier way:
With a battery powered Digital Multi-Meter (DMM) that has a low voltage AC range. It does not need to be True RMS or even accurate.
Play a mono tone test track.
Measure each channel Red to Black terminal, there should be a few Volts
Measure amp's Red terminal to Red terminal, there should be about zero Volts.

Have the receiver loose now- but found one problem- My bad- I use Spotify about 90% of the time and in the accessibility section- I had the speaker balance offset to the left side about 10%. That was causing the "weak" right channel problem.

But now that the Yamaha is out of the system- It should be possible to do some more testing- I think the out of phase problem was also my fault because of a scope setting (invert channel B?) not sure, but last time I checked, the problem was gone.

 

[isolar8001]

Man, this thread is like a bad case of shingles that last forever.

 

[lovinthehd]

Thanks for the question!
But at that time, and with that receiver Yamaha RX-V365 there was no YPAO functionality available. I have had that receiver for years and it does not even have a jack for a microphone anywhere on it. So I was doing it all by trial and error. It took weeks to get it sort of normalized.

I sort of got frustrated and changed amps to a Denon AVR-S970H which I'm trying now. It has a EQ app and a micophone and I'm in the middle of getting it set up now. I ran one calibration test and it was OK, nothing to write home about. But a lot of changes were put into the mix and I did not have my new speakers installed and located where they should be. I am using two flat panel ( ceiling tiles) with the Dayton exciters glued to the backs- surprisingly, they do work fairly well, but the room has a vaulted ceiling and is about 24ft wide and 16 feet deep, so it needs a lot of help. I am using the two flat panel "speakers" hanging from the ceiling and slung down facing my seating position across the room. There are also the usual 5.1 channel surround speakers beyond that.

Overall- I'm mostly interested in the audio qualities of any system. We don't watch movies, and the wife can't stand much volume while I also have tinnitus, so it's hard for me to enjoy at any level she can tolerate.

Yes I have some headphones, but when she sits on the couch and I have the headphones on I can't hear her asking me questions or whatever, so most of the time- no headphones.

So am trying for a lower level listening experience with max intelligibility of voices in the music. And it's 90% Spotify, 5% You Tube and 5% DVD's or other CD's .

If you have any questions or comments, I am always here. I'm sure I could learn a lot.

The new receiver was a handfull to get going and some of the instructions were a bit confusing, but it's working fairly well now- not sure if it can be made simpler to operate? The HEOS and Denon apps are separate from the Spotify app and the remote for the Denon AVR-S970 is a bit rough on the volume adjustment, so it's smoother to use the HEOS app for volume adjustments- which are quite frequent because of the variability of the Spotify source, but you find yourself constantly switching from APP to APP to control everything.

As to the Spotify volume thing, check out "volume normalization" in the settings for Spotify, might try that. What's the issue with the Denon's volume control?