NAD T778 Audio/Video Receiver (AVR) Review

[Chromatischism]

Amp vs. speaker is correct, but Dirac requires you to take nine different measurements in different locations, precisely so that it can distinguish between amp/speaker and room effects.

It will be a consistent feature of every measurement, so it will attempt to correct it. That said, the futility of trying to correct near 20 kHz and Dirac's low-frequency limit should also be considered.

 

[T3RIAD]

It will be a consistent feature of every measurement, so it will attempt to correct it. That said, the futility of trying to correct near 20 kHz and Dirac's low-frequency limit should also be considered.

Well, the point of my question was that actually, if it only happens to the analog inputs and not the digital, then it won't correct it, because the test tones it plays (digitally) won't have the problem.

So again, does the FR issue apply to digital as well, or just analog?

In the latter case, it won't be corrected. Though this isn't a deal breaker for me, because I would never use the analog input of an AVR.

 

[yourmando]

The problem is that you introduce an ADC-DAC cycle in that path (Denon pre-outs are analog) and you cannot use the amps in that Denon but you need another set of amps for all the channels or active speakers for all. If this is done for HT, the latency of that path relative to whoever is doing the video decoding and rendering may get quite a bit out of sync. So feasible but not very practical.

Correct. You'd ignore the built in amps. You still have a cheap pre pro if you just use the pre outs. Seems like a waste at first, but at their volume it's still cheaper as a pre pro.

There would added latency as with any DSP powered active speaker, but there should be no sync issues. The pre pro would think the speakers were further away because of the ms latency and compensate for that delay. Same as if you plugged in a Kii Three with it's built in DSP.

It would not be cheaper or easier this way--total price would add up to entry level Dirac capable pre pros or more. But could be an option for someone who wants to heavily customize.

 

[Vasr]

Speaking as an engineer,
...

So stop blaming the engineers, and in particular keep the targeted insults to a minimum, please.

Horrible take on my post.

If you can point to what you took as targeted insults in the post you quoted and it is legitimate I am happy to retract. This is an unnecessary and unjustified diversion.

What I explained was the raison d’etre for the forum and the philosophy behind the measurements and its general interpretation which was misunderstood by the post I was responding to because it interpreted better as better sounding. If you disagree with that fine, you are disagreeing with the forum which collectively has more experience than any one engineer. What you said could also be considered as insulting to the whole forum but people here can differentiate between disagreements in opinion and not take it as an insult.

Nothing in my post blamed engineers for the product directly, you seem to have a sensitivity to criticism of engineers as an engineer. I get that but you cannot do bad takes because of it. I specifically mentioned that the relative "poor engineering" of the product may come from any of the reasons - economics, sloppiness, pragmatics, etc.

The point as I specifically mentioned is that without being an insider, you judge the product of the company as a whole. Whether it is a marketing decision or engineering decision isn't relevant. As a consumer, how would you know? We can only assume the same philosophy carries through to other parts and it might be designed to be "just enough". Just enough for what? Who sets the criterion? Marketing who are driven by P&L typically. So, as a consumer, why wouldn't I assume the same would lead to taking shortcuts elsewhere. So, I discount such products. You may disagree with it but lecturing me or the forum to think otherwise is a bit rich when you yourself seem to feel insulted so easily.

 

[Vasr]

Amp vs. speaker is correct, but Dirac requires you to take nine different measurements in different locations, precisely so that it can distinguish between amp/speaker and room effects.

No, this is not correct from my understanding of the technology. All room eq systems take multiple measurements so as not to correct only for a narrow listening point. So, they average the responses over multiple positions and correct for it. Dirac, in addition, uses the multiple position measurement to detect reflection based artifacts to do its proprietary algorithms.

 

[Vasr]

There would added latency as with any DSP powered active speaker, but there should be no sync issues. The pre pro would think the speakers were further away because of the ms latency and compensate for that delay. Same as if you plugged in a Kii Three with it's built in DSP.

Doesn't necessarily work that way. A DSP can only delay the signal not speed it up. So all that the pre pro can do is delay all equally. So the total latency would be where the slowest of the audio is.

Now, the sync depends on who is doing the video rendering. Say the TV with the passed through HDMI signal. It has no way of knowing how much the audio latency is. To make it sync with the audio, it has to delay the video rendering. So, it may provide manual settings for lip sync that would delay the video but it has limits on how much it can delay and long latency especially when you introduce multiple hops and conversions can be more than it can handle.

I get your suggestion in theory. But I am not sure it is very practical to do unless one has no other choice.

 

[voodooless]

Why should AVR companies spend money making numbers go up that don't affect the sound?

Why do you think they need to spend more money? They just need better engineering. That does not need to cost more money.

How is that any different from the $10,000 amps that have silver wiring and high-end capacitors and audiophile fuses in them? Those products are also technically better, but they get ridiculed here for good reason, IMO.

Those products are almost never objectively better.. so what’s your point?

 

[yourmando]

Doesn't necessarily work that way. A DSP can only delay the signal not speed it up. So all that the pre pro can do is delay all equally. So the total latency would be where the slowest of the audio is.

Now, the sync depends on who is doing the video rendering. Say the TV with the passed through HDMI signal. It has no way of knowing how much the audio latency is. To make it sync with the audio, it has to delay the video rendering. So, it may provide manual settings for lip sync that would delay the video but it has limits on how much it can delay and long latency especially when you introduce multiple hops and conversions can be more than it can handle.

I get your suggestion in theory. But I am not sure it is very practical to do unless one has no other choice.

Right--agree with all your points, and that there is an upper latency limit.

We do know it's possible because there are plenty of DSP based active speakers, or subs and speakers behind a mini dsp. So your PC based latency would need to be in line those solutions. AD back to DA adds about 1.4ms of latency for 16 in/out at the same time. A DSP based speaker might have 90ms of latency, and a low latency mode closer to 1ms.

Yes, you wouldn't do it if there was a simpler choice--as I mentioned, only if you needed customization beyond what you could get in the pre pros. Definitely easier to buy a Dirac capable unit if that's all you need.

 

[Matyam]

Well to any prospective 778 owners don't be put off by the measurements on here even though they are doing a valuable service and I'm sure a 779 will be better because of it.
After flaffing around with rew, graphs,various eq devices listening to lots different equipment because I'm still learning i came to the conclusion the room in whatever house is the biggest problem. I have no particular loyalty to nad as such even if i still have a pre power from the eighties,I still use a denon cd changer and dvd player even.
The nad is being rubbished by people who have never even heard it which is hilarious, dont be a sheep listen in your own home and make your own mind up.
Denon and yamaha will hopefully catch up as i miss my ax1 but for now dirac with nad for us mere mortals is the leveller for enjoyable music ,cute over and out.

 

[TweekinTubez]

Horrible take on my post.

“Dr. Strangelisten or: How Everyone Here Besides Me Reacts Inappropriately to Criticism.”

All kidding aside the real question to the marketing dudes at Denon is why do their engineers only build beautifully measuring AVRs that are butt ugly? Will straying too far from the utilitarian Panzer aesthetic negatively affect their precious frequency response?

Can I get a tone measurement?

 

[Chromatischism]

Well, the point of my question was that actually, if it only happens to the analog inputs and not the digital, then it won't correct it, because the test tones it plays (digitally) won't have the problem.

So again, does the FR issue apply to digital as well, or just analog?

In the latter case, it won't be corrected. Though this isn't a deal breaker for me, because I would never use the analog input of an AVR.

Thought more about this and looked back at the measurements. It's a good question. Amir seems to think that the rolloff is due to digitization of the analog input. If that's the case, the amps are not the cause and it wouldn't exist in the Dirac sweeps.

Half a dB at 10 kHz, 1 dB at 15 kHz, and -1 dB at 18 Hz might not be deal breakers to many people, but it's not hard to achieve linearity these days at a lower price point, so it doesn't look good.

 

[T3RIAD]

@amirm Did the frequency response problem exist just for the analog input, or also for digital inputs?

 

[Dmitri]

I can't say it will never do so without knowing the technical details of the system but in my experience across multiple systems, I have never encountered corrections to raise the frequency response across a band in lower frequencies. There may be ways to force them to do so in manual tweaking but I have never tried to.

Note that the room-eq systems do not know if the fall-off is due to the amp or the speaker or some room mode. It is far more common to encounter such fall-offs due to speaker limitations than either of the other two in which case eq is not very effective in extending the lower FR of speakers and pumping large amounts of power to do so may be useless if not harmful.

Despite what the target curve is (or even what is shown as theoretical corrected curve which is pure fiction in some systems), natural slopes are left as is but they will smooth out deviations as they determine it. Just to illustrate from a known system, in REW, it will generate filters only when the response curve crosses the target curve successively in opposite directions in a local area. This detects peaks and troughs but will not consider fall-offs.

They may tame higher frequencies by cutting with shelf filters (ARC seems to do this in full range correction) to get closer to a target curve slope. But most corrections here will create at best locally optimal (in seating position) but likely artifacts everywhere else.

Thanks for the time spent and clarity of your response. Having not looked at them for awhile, I had this image in my head of my ARC target curves being flat to 20kHz knowing full well that my speakers don’t. I went back and looked, and my target curves do roll off. So, assuming similar to ARC in this regard, Dirac would not correct for the amplifier’s drop off from 5k on.

 

[BDWoody]

Well to any prospective 778 owners don't be put off by the measurements on here

Too late.

The nad is being rubbished by people who have never even heard it which is hilarious

And it's being defended by people who are determined to miss the point. No one doubts Dirac makes a big difference (I don't think), but personally, I am just not in a rush to get a mediocre processor for a great correction system.

cute over and out.

Thank you, and take care now.

 

[3dbinCanada]

Amp vs. speaker is correct, but Dirac requires you to take nine different measurements in different locations, precisely so that it can distinguish between amp/speaker and room effects.

YPAO takes 9 as well including angle and height but its not to distinguish between amp and speaker but speaker and room effects. Dirac is no different.

 

[T3RIAD]

YPAO takes 9 as well including angle and height but its not to distinguish between amp and speaker but speaker and room effects. Dirac is no different.

That's what I meant. It distinguishes between (amp + speaker) and (room) effects. But it can't distinguish between amp and speaker.

 

[TonioRoffo]

Sure, look here: https://www.avsforum.com/threads/the-official-nad-t-778-thread.3123286/page-38

vs

Strange, so they want to cut costs, put cheaper coils in, but leave the modules, well, modular. They might as well have licensed the whole UcD thing and put it all on one board.

I guess this leaves a route open to plug in NC500 modules, if the pin out is compatible (power would be less of course)

 

[voodooless]

Strange, so they want to cut costs, put cheaper coils in, but leave the modules, well, modular. They might as well have licensed the whole UcD thing and put it all on one board.

I'm guessing Hypex only licences modules, and I'm also guessing they are made by Hypex, just a bit lower spec.

I guess this leaves a route open to plug in NC500 modules, if the pin out is compatible (power would be less of course)

No, it's not compatible.

 

[Matyam]

Let's face it all amps over a certain snr sound the same within there tolerance did anyone ever win the Bob carver challenge ? or was it only asr experts

 

[Billy Budapest]

Let's face it all amps over a certain snr sound the same within there tolerance did anyone ever win the Bob carver challenge ? or was it only asr experts

Carver’s challenge that he could make a solid state amp sound like any other amp, or like a tube amp? I imagine that it would not be very hard to take the electrical characteristics of one amp and engineer another amp to measure similarly in the areas that would affect sound quality.