Review and Measurements of Yamaha RX-A1080 AVR

[scooter]

From what you say, I would not be surprised if it was 3 Ohms, usually with 3-way speakers.

Woofers are the same, 16 ohms each, connected in parallel directly before crossover network = 8 ohms.
Midrange is 6 ohms and Twitter is also 6 ohms, connected in parallel but after the crossover network. It will be complicated to calculate common resistance of midrange and twitter, inductive and capacitive resistance elements are added.

 

[RichB]

I still think that there's something mischievously greedy going on.

THX reference levels are 85 dB at the listening position. With 6 dB for headroom peaks, we're looking at needing to achieve 91 dB (peak) at the listening position.

SPL drops by 6 dB with doubling position. So at 8 feet (not an unreasonable distance from a 50-60 inch flat screen's mains and centre channel speakers), 85 dB at one foot would drop by 18 dB. One would, therefore, need a sound system capable of 103 dB (continuous) and 109 dB (peak) at one foot in order for THX reference sound intensity plus headroom to be achieved at a listening position of 8 feet.

But wait, there's more...

Everyone, even the manufacturer's, know that people like to choose their own speakers to suit their spaces. The WAF is a common consideration that drives speaker cabinet sizes down. Smaller speaker cabinets mean smaller speakers, which means greater exclusion is needed per dB. This requires power... lots of it.

Thirty years ago, 8 ohms (nominal) was the most common loudspeaker impedance. Today and, indeed, for the past 10 years, 4 ohms (nominal) is the most common. Yet despite all of this, consumer AVR manufacturers insist on gain stages capable of driving loads down to 6 ohms... and not very cleanly either as they scrimp on power supplies and heat sinking needed to keep amps from running out of current or going into thermal overload.

So the little game of blind man's bluff continues to play out. Marketable features are added but the fundamental issues of power supplies and heat management go largely ignored, as do the practical implications of maintaining reference levels at reasonable distances, though common loudspeaker loads, without the amp reaching its limits.

The problem with these calculations is that if you are little off, the power calculations go through the roof.
Here is the estimate from crown calculator. Removing any headroom for 101 dB (104 stereo) the amplifier power required is computed to be 387 watts. That sound ok but since there is no ohm rating, it likely assumes 8 Ohms, but the Salon2s are basically 4 Ohms speakers so the better sensitivity for this calculator is 83. When that is plugged in, the required amplifier power is 773 watts.

I measured the SPL with 400 Hz and 1kHz tones stereo tones played at 2.83 volts. Taking into consideration the 4 Ohms load, this is two watts and it generated 86 dB, coincidentally the rated sensitivity. Using that anchor, the following power and SPL levels are obtained with stereo content:

In reality, 104 dB requires only 128 watts not the 773 watts from the Crown calculator.
This was a sanity check because I was surprised that I could not clip the AHB2 bi-amping the Salon2s even when turn the volume up past anything I found enjoyable.

This should indicate that an AVR should have no problem driving the Salon2s but that is simply not the case. I had tried driving the Salons with the Yamaha RX-A820 100WPC AVR and it was flat. I surmise that linearity into load and distortion are the culprits.

- Rich

 

[GrimSurfer]

It's all a matter of what you plug into the calculator, Rich.

3.5M is more than 8 ft. 101 dB at the listening position is much more sound pressure than the THX reference calls for. 0 dB overhead is less than ideal. 83 dB/W/m is a horribly inefficient loudspeaker.

Crown makes amps for public address (I know that ppl call them "pro" amps but the PA application is featured in Crown product literature), so perhaps their calculations include an ambient noise correction?

In the context of all this, getting an outrageous power figure makes sense. This is not the fault of the basic methodology but that figures being used and, perhaps, corrections being applied.

 

[bravomail]

Conclusions
Almost any hope we had of the Yamaha RX-A1080 being a stand-out among other AVRs is dashed. We are still in the red when it comes to DAC performance. We still have strangeness in audio pipeline. We still have ADCs that are not transparent to analog inputs.

Thx for review, Amir! I have seen other Yamaha AVR measurements (on other websites) so no huge surprise here. Power supply noise, Yamaha? Oh com'on! Just put PS brick outside of case!

 

[blueone]

It's all a matter of what you plug into the calculator, Rich.

3.5M is more than 8 ft. 101 dB at the listening position is much more sound pressure than the THX reference calls for. 0 dB overhead is less than ideal. 83 dB/W/m is a horribly inefficient loudspeaker.

In that context, getting an outrageous power figure makes sense. This is not the fault of the methodology but that figures being used.

I can't agree. The calculator specifies 1W at one meter, meaning it assumes 8 ohm speakers, and his Salon2s really are 4 ohm, so the math dictates they will dissipate 2W with 2.83 volts, so plugging 83db into the calculator is reasonable. 101db peaks at a listening seat is also reasonable for reproducing live performance level sound (I've measured at least that much at performances in medium-sized venues like bars), though I seldom listen that loudly at home. The unknown I'm wondering about is whether the calculator takes two channel stereo into account or is assuming mono. If mono, the per-channel power requirement for stereo might be about 3db lower, or only about 350 watts. I looked at the Crown web site and it implies a mono assumption.

 

[GrimSurfer]

There's a difference between "desired level" and "peak". This terminology is throwing ppl off.

You are correct that nominal impedance must be considered in conjunction with a power output requirement. 83 dB/W/m is an inefficient loudspeaker, though any reasonable person would admit that loudspeaker manufacturers routinely over rate their speaker efficiencies.

As you point out, the Crown calculator assumes mono. In stereo, to equidistant 101 dB sources would generate 104 dB. So all you'd need is 2x 98 dB to generate 101 dB at the listening position.

As for online calculators, I don't use the Crown ones. I'm not in the PA business. I use Sengpeil Audio calculators.

http://www.sengpielaudio.com/calculator-spl.htm

And since we're on a thread about AVRs, don't forget that an accurate spl calculation will involve varying distances AND anywhere between 5 and 9 speakers (not all of which will be calibrated to deliver the same spl).

 

[HammerSandwich]

This states that THX requires 105dB per speaker at the listening position. Bad link?

 

[GrimSurfer]

Peak vs average?

85 dB average is used because it is the cut-off for sound induced hearing damage. Every 3 dBs over 85 halves the time for permanent hearing damage.

 

[peng]

This states that THX requires 105dB per speaker at the listening position. Bad link?

That is correct, THX's 85 dB average, 105 dB peak requirement is for per speaker/channel. Obviously with more speakers playing you will get more spl, but again, the 85/105 dB is on per speaker basis.

 

[HammerSandwich]

Peak vs average?

Full-scale peak, but that's what sets the wattage requirement, right?

Every 3 dBs over 85 halves the time for permanent hearing damage.

IIRC, OSHA says 90dB for an 8-hour workday, but the standard's designed to allow retired factory workers to converse, not hear music with fidelity.

 

[RichB]

This states that THX requires 105dB per speaker at the listening position. Bad link?

That is correct. THX is 85 dB with 105 peak.
Since amplifier power is important, you really need to consider the gain from 2 speakers and the room.
If they mean peak, the that is 102 dB and still under 100 watts.

Here is one of the better calculators:
http://myhometheater.homestead.com/splcalculator.html

Here everything for gain was set correctly for the Salon2's.
This calculator predicts 224 watts for 102 dB when in fact 128 watts provides 104 dB.

- Rich

 

[DonH56]

I wonder if digital scaling for the S/PDIF (TOSLINK) inputs is messed up so the internal DAC is being overdriven... Or somehow being driven single-ended instead of differentially.

 

[scooter]

Also Yamaha lies when it states in RX-V583 manual that it has 7 individual amplifiers for its 7 channels. If this was true, then connecting my NS-777 in biamp configuration would have shown some improvement, total impedance seen by each used channel is increased and therefore less stress on amplifier. But it is a big marketing LIE! I've tried...

 

[RichB]

Here is what THX says about reference level:

https://www.thx.com/blog/questions/what-is-the-reference-level/

WHAT IS THE REFERENCE LEVEL?
THX Certified Audio products are designed to let you experience movies the way they were meant to be heard. On every THX Certified AV Receiver the “0” on the volume dial represents THX Reference Level, the exact volume level used by the moviemakers and sound artists in the studio.

For manufacturing receivers and speakers, achieving the THX Reference Level is no simple task. It requires a tremendous amount of power to drive an audio system effortlessly without clipping or distorting. To ensure the audio products reach this peak performance THX developed a set of standards as part of its THX Dominus, THX Ultra, THX Select and Integrated System certifications.

• Experience Studio Clarity: THX Certified Receivers reproduce studio Reference Level, 85dB SPL with 20dB of headroom.
• Reference Level for your Room: THX Dominus, THX Ultra, THX Select and THX I/S certification categories deliver Reference Level performance in your specific room size.
• Distortion-free Playback: THX Certified Receivers and speakers are designed to recreate Reference Level with minimal distortion.

I've always found this dubious.
First, 85 dB at home is VERY loud and I suspect uncommon for folks using AVRs.
Second, 0 as "reference" in my room (and I expect most rooms) this requires over 20 dB of attenuation.
What for, to get a particular number. I am not a numberist.

There is another method, set the volume to your preference

- Rich

 

[GrimSurfer]

Full-scale peak, but that's what sets the wattage requirement, right?


IIRC, OSHA says 90dB for an 8-hour workday, but the standard's designed to allow retired factory workers to converse, not hear music with fidelity.

Q1: Not really. Think about how you measure spl. You (or the amp/AVR) do a frequency sweep or transmit a broadband signal. The only thing that changes (or not) is the frequency. So there is no peak to measure. There are room resonances (not to be confused with room gain) but these are minor relative to the average spl.

[Side Note: 85 dB is the highest safely sustained limit. The audio community uses this because (1) it is safe and (2) it places the spl as far above a space's noise floor so that the sound being transmitted is overwhelmingly dominates. Sustained spl is measured because it is far easier to accurately capture than peaks. Peaks can cause analog devices' needles (which were the most common professional spl meters) to over-sweep. Room gain can greatly increase peak spl at a certain frequency, skewing the results far more than an average.]

To find how much wattage you need to reach this spl, the result of the calculation will be continuous power. This is much harder for an amp/AVR to sustain. So if it can sustain 85 dB spl at the seating position, hitting 15-20 dB during a very short duration peak is likely. There are many reasons for this, of the least of which include the capacity of a good amp's power caps and its excess cooling capacity.

Q2: I'll take your word for that. It's been a while since I've looked at OHSA and NIOSH standards, so I'll take what you're saying as correct. 85 dB is what the medical research says, so I use this more than what industry and unions have conspired with government to call acceptable during an 8 hr shift.

 

[DonH56]

Also Yamaha lies when it states in RX-V583 manual that it has 7 individual amplifiers for its 7 channels. If this was true, then connecting my NS-777 in biamp configuration would have shown some improvement, total impedance seen by each used channel is increased and therefore less stress on amplifier. But it is a big marketing LIE! I've tried...

If you can hook up seven speakers, and they all play with independent sounds (such as the calibration test tones), then you have seven individual amplifiers inside. I really doubt that Yamaha is stating that wrong.

Bi-amping in AVRs may not provide any additional headroom. Since frequency bands are not split within the AVR all amplifiers still see the full signal voltage. There is essentially no increase in voltage headroom, and current headroom depends upon the load. The load may or may not change and how much depends upon the speaker's crossover implementation and design. Also note some speakers (ESLs, some planar-dynamics and conventional designs especially using ribbon tweeters) actually have lower impedance in the HF region, not the bass. To me, the big lie is that "passive" bi-amping as implemented in an AVR (running the amps full-range and using the passive speaker crossovers to split the frequency bands) provides any real benefit.

FWIWFM - Don

 

[peng]

https://www.thx.com/blog/questions/what-is-the-reference-level/

Second, 0 as "reference" in my room (and I expect most rooms) this requires over 20 dB of attenuation.
What for, to get a particular number. I am not a numberist.

You are not an AVR user as far as I know. If you are, you would find that most Onkyo, D&M and Yamaha's are within the ball park to produce 85 dB average at volume 0 if you sit 10-13 ft from the speakers, without attenuation (may be a few dB at the most).

 

[peng]

Thanks PENG. I have upgradeitis I believe. So do you think I can improve on the performance with a solid integrated with room correction?

Which integrated with room correction are you referring to? If it is the Lyngorf TDAI-2170, I thought Amir reviewed it and it did not measure too well. Whether you can hear the difference between an AVR, integrated amp (there are many, so which one?), or separate preamp/power amp or not, the KEF R3 probably deserve something better than an AVR. Some integrated amps could be just adapted from their AVR cousins, so just be careful if that's an issue for you.

 

[peng]

It depends on source material, listening levels, where distortion occurs in the FR, and whether that distortion is even or odd order. It also depends how the distortion was measured. Was the device cold, warm, or hot? Is the distortion figure weighted or unweighted.

It also depends on the sensitivity of the listener and the degree to which they can distinguish between clean sound and distortion.

Of course, but a) the harmonic distortions spectrum of class AB amps, are not drastically different, and b) we are talking about <0.05 % THD+N 20-20,000 Hz, so no, I wouldn't worry about even, odd, low, high order.

 

[RichB]

If you can hook up seven speakers, and they all play with independent sounds (such as the calibration test tones), then you have seven individual amplifiers inside. I really doubt that Yamaha is stating that wrong.

Bi-amping in AVRs may not provide any additional headroom. Since frequency bands are not split within the AVR all amplifiers still see the full signal voltage. There is essentially no increase in voltage headroom, and current headroom depends upon the load. The load may or may not change and how much depends upon the speaker's crossover implementation and design. Also note some speakers (ESLs, some planar-dynamics and conventional designs especially using ribbon tweeters) actually have lower impedance in the HF region, not the bass. To me, the big lie is that "passive" bi-amping as implemented in an AVR (running the amps full-range and using the passive speaker crossovers to split the frequency bands) provides any real benefit.

FWIWFM - Don

I don' disagree but I do remember @amirm measured a case where bi-amping was beneficial when in lower amp clipped and the upper amp remained clean.

I have pushed the AHB2's single and bi-amped and with separate clip indicators, it was possible to see which amp clipped. The lower amp clipped 1 dB before the upper amp. So, as you stated, this looks to be voltage clipping. Either way, my listening habits do not clip these amps.

I don't bi-amp for power, I bi-amp for clarity. IMO, the Salon2's sound cleaner when the crossovers are not connected and driven by two amps.
A quote on AVS attributed to Kevin Voecks stated that there can be improvements in clarity. I have passed SBT's and conducted them with a friend who also passed when driving a single speaker and using stacking banana plugs.

- Rich