It shouldn't have made a difference but it did...

[mtrycrafts]

You know I may try that blind test thing this weekend as well as the SPL meter.

That will tell the tale.

You may want to use that spl meter with a steady test tone when switching those loads, not music signal.

if levels by the spl is the same or close, have her do it randomly, have her write it down and you too, then compare in the end. Do at least 10 trials

 

[mtrycrafts]

I tried the blind test this morning and could not determine any significant difference with my ears. I didn't have time to set up my SPL meter. Then it dawned on me...

I'm not going to be able to resurrect the initial conditions, because I re-ran YPAO EQ when I installed the new center. The surrounds had to have been re-EQ'ed to match the front. With the new center, the front soundstage changed, so the receiver had to have changed the PEQ settings for the surrounds. But since I never wrote down the previous EQ settings I'll never know for sure.

Now you see why it is so necessary to do things in consistently, changing one item at a time, etc.

 

[mtrycrafts]

...
You are not going crazy. Realise that hearing is a b..... Also, as Peng said, something is wrong here. Looking at the quoted Yamaha note, they give 144W for the 8 ohm setting and 78W for 6 ohms.That is almost 3 dB but 8/6 ohm is only 2.5 dB. Not a great difference, until one calculates that with 144W for 8 ohms, exact reduction should have given 108W and not 78W - now it seems somewhat more enigmatic.

.

I think that the design, the voltage selected that is available at the 6 ohm setting can be anything the designers select, no? Hence, it can be any dB difference.

 

[PENG]

But definitely try what Davemcc suggested.

I was going to say the same Now we know for sure Davemcc had the best idea, it worked! I wish more people would do a blind test before reporting those day and night differences. I know, it will never happen.....

 

[Buckeyefan 1]

Is it possible in 8 ohm mode, the capacitors are drained much more quickly from the demanding fronts, and the surrounds don't have the available current to push them as opposed to in 6 ohm mode, the current isn't running as quickly - thus allowing additional reserves in the capacitors to power the surrounds for that nanosecond burst?

Think of it as having 5 "plumbing" valves (speakers) and one source of water (amp). If 3 were closed, the remaining two would see higher pressure. If none were closed, the pressure would drop. The 8 ohm setting would have the valves wide open. The 6 ohm would have them closed 25%, thus allowing higher pressure. Since in 6 ohm mode, not as much current is going to the mains, that allows more current to be distributed to the surrounds if/when they need it.

 

[jcPanny]

Receiver settings

It didn't come to me until I was doing the blind test. But now I'm not so sure YPAO is the culprit here. As the FRONT setting on YPAO is supposed to match everything to the Front L and R speakers which did not change. Oh well, as the blind test didn't distinguish any difference between the two setting.

Maybe I'm going crazy.

MP,
Sounds like the speaker upgrade and recalibration made the difference and not the impedance setting.
Here is another A/B test. Experiment with turning the Yamaha PEQ ON and OFF. The PEQ on most mid-fi receivers is not that great and it might sound better with the EQ off.

 

[mpompey]

I feel so stupid. I was all excited over nothing.

I'll try turning off the PEQ and recalibrating levels without and see how that sounds. I always figured some PEQ is better than no PEQ.

 

[mtrycrafts]

I feel so stupid. I was all excited over nothing.

I always figured some PEQ is better than no PEQ.

Don't be so hard on yourself.

Some PEQ may be better for you, a preference. Just be careful when you compare things with all the different changes.

 

[mpompey]

I'm not crazy, I'm not crazy!

A while ago I posted that I heard significant improvement from my rear surrounds when I switched my receiver from 8 ohms to 6 ohms. This improvement defied all logic, electrical theory, etc. When I did the blind test between 8 and 6 ohm setting I found no difference. Then, I pulled out my SPL meter and tested; and still I found no difference. Where did this perception come from? After reading all the advice in the forum, I just chalked it up to subjective hearing and having gone crazy.

But through a fortuitous set of circumstances, I've been able to recreate the original setup and conduct detailed tests with an SPL meter. And I've found the answer.

The issue wasn't that I changed the ohm setting from 8 to 6. The issue was with the center speakers themselves. My old center speaker was 8 ohms, my new one 6. All of my other speakers are 6 ohm. When I put the old 8 ohm center back on, (receiver at 8 ohm) I heard the drop in response and clarity from the rears. This was after I recalibrated all speakers to the AVIA test tones. When I took it off and put the 6 ohm center back on (receiver at 8 ohm), and recalibrated to AVIA everything was back to normal, clear, spacious, the new sound that I was hearing.

So now the question is:

Is this behavior from my RX-V1500 normal? I contacted Yamaha and they said I could safely run 4 ohm speakers on the front, and have 6 ohms on everything else. What could be the issue here?

Not that I'm looking for issues, or looking to swap my receiver, as the theatre now sounds fantastic with the new center; and new performance out of the rears. I'm literally re-watching all my collection, and getting a new auditory experience. And happy that I'm not going crazy.

 

[mtrycrafts]

A while ago I posted that I heard significant improvement from my rear surrounds when I switched my receiver from 8 ohms to 6 ohms. This improvement defied all logic, electrical theory, etc. When I did the blind test between 8 and 6 ohm setting I found no difference. Then, I pulled out my SPL meter and tested; and still I found no difference. Where did this perception come from? After reading all the advice in the forum, I just chalked it up to subjective hearing and having gone crazy.

But through a fortuitous set of circumstances, I've been able to recreate the original setup and conduct detailed tests with an SPL meter. And I've found the answer.

The issue wasn't that I changed the ohm setting from 8 to 6. The issue was with the center speakers themselves. My old center speaker was 8 ohms, my new one 6. All of my other speakers are 6 ohm. When I put the old 8 ohm center back on, (receiver at 8 ohm) I heard the drop in response and clarity from the rears. This was after I recalibrated all speakers to the AVIA test tones. When I took it off and put the 6 ohm center back on (receiver at 8 ohm), and recalibrated to AVIA everything was back to normal, clear, spacious, the new sound that I was hearing.

So now the question is:

Is this behavior from my RX-V1500 normal? I contacted Yamaha and they said I could safely run 4 ohm speakers on the front, and have 6 ohms on everything else. What could be the issue here?

Not that I'm looking for issues, or looking to swap my receiver, as the theatre now sounds fantastic with the new center; and new performance out of the rears. I'm literally re-watching all my collection, and getting a new auditory experience. And happy that I'm not going crazy.

Not sure what will happen with 4 Ohm fronts except that a different speaker will have a different frequency response, radiation pattern, sensitivity, etc.
I think that is what issues you also had with the 8 Ohm and 6 Ohm speakers.

Perception is a curious thing. Hard to know why and when it will misguide you. Certainly not predictable.