NAD Wireless USB DAC 2 Review

[PeteL]

I did a little bit of search to find the type of "3 selectable Channel" RF (WiFi? 802.11?) communication is being used.
I found out that the referenced "3 channels" may be those 3 that are considered the "non-overlapping (20MHz)" ones (802.11b/g/n @2.4GHz WiFi-band) shown in diagram below…
View attachment 211387
Those same 3-channels are also used by BlueTooth, baby monitors, car alarms sensors, garage doors, MicrowaveOvens, Zigbee/SmartHome devices, etc.
View attachment 211388
Theoretically the 802.11a/n/ac offers 25 such channels of which only 9 are unrestricted (non-DFS) allocation
View attachment 211389
I got nowhere: Even the NAD site lacks any information about the RF technology or type or specs.

The NAD DAC2' FCC certification shows approval for 2.4GHz band but another source alluding to: "The wireless transmission takes place at frequencies of 2.4, 5.2 and 5.8 gigahertz, and you can access the three channels by using the manual switch…"

Not that @amirm' test results showed any disruptions or drop-outs (etc.), but at least one other person talked about line-of-sight obstruction of the wireless signal.
I had an AudioEngine D2 wireless-audio system (using 17-band spread-spectrum in the WiFi (2.4GHz band) which had co-channel interference issues with other neighborhood WiFi activity.

It should not be this difficult but WiFi "6E" (5.925 to 7.125GHz) may even increase the line-of-sight related reception problems.

It's obviously a point to point transmission, not networking so it wont be bound with such standards like 802.11. But that said, trying to do that without any frequency hopping in such a crowded band is in my opinion very likely to experience some difficulties, and the previous post seems to reference "diversity antennas" which to me suggest that they may be trying to do that, transmit on a single (well 3 since there are three channels) frequency carrier. Hard to know for sure but a pair of diversity antennas is more alike antenna hopping (not exactly but rough idea) instead of frequency and sounds like a weird choice in this band.
Now as a more general thought, the FCC filing is obviously more reliable than this other source.

 

[pseudoid]

Hard to know for sure but...

...but... you (I?) can't have the expectation that NAD provide any technical information, at this price point.
I am not tempted enough to buy one, just to - carefully - take it apart...

 

[PeteL]

...but... you (I?) can't have the expectation that NAD provide any technical information, at this price point.
I am not tempted enough to buy one, just to - carefully - take it apart...

Well I was not clear, but this part is for sure, they use a pair of antennas arranged as a diversity system. Taking one appart wont tell you anything about the carriers or modulation protocols used. Already a spectrum analyser will give you more info. That's the unknown part. Before you take it apart, the pictures on the FCC site are quite clear.

 

[amm]

@PeteL here you go:

During the measurement, only the transmitter was turned on. It switches automatically between three frequency bands of 2.4 GHz, 5.2 GHz and 5.8 GHz, each time it uses a new channel within each band as indicated on the spectrum analyzer display. The spectrum analyzer was used in trace hold mode until the transmitter switched to all three frequency bands and tried various channels within each band.

 

[Xyrium]

Very neat. Is that RF transmission? I'm not sure if they can implement bluetooth from the transmitter to receiver of course, but...

$99 would get my money on a neat little device like this.

Edit: Post right before mine cleared up the method of transmission. Thanks!

 

[pseudoid]

I'm not sure if they can implement bluetooth from the transmitter to receiver of course, but...

Let's ask Sony:

...The range of the Bluetooth® connection is approximately 30 feet (10 meters). However, maximum communication range will vary depending on obstacles (person, metal, wall, etc.) or electromagnetic environment...

Bluetooth is a different animal (protocol) than WiFi.

 

[Cote Dazur]

Those colorations are left to the characteristics of your amplifier, headphones/speakers, or the addition of whatever DSPs/ASPs you so choose

Actually, the main factor is the room and speaker positioning, then the speakers themselves.
Everything else contribution is so small it has almost no effect if they are working properly.

 

[mikemcsw]

Actually, the main factor is the room and speaker positioning, then the speakers themselves.
Everything else contribution is so small it has almost no effect if they are working properly.

what a joke! i believe objective reasoning to a point, but i still have not heard about any measurements that determine instrument separation and soundstage, and without moving position of speakers or changing anything but amplifier, i have heard DRAMATIC differences by amp alone, with Pass Labs and Mcintosh having the best in this regard out of about 30+ amps i have tried... People can believe whatever they want about objective measurements, but until i hear about any measurements thtat actually determine how well instrument separation and soundstage is, i believe in both objective and subjective impressions, and it is not just bias. Even my wife who never does critical listening, she immediately stated that when i introduced either of the 2 amps mentioned that she could hear a dramatic difference...and the other amps were not sleepers or junk or malfunctioning...some amps are clearly designed better....DACS i have heard some differences but not nearly as daramatic as when i go to one of the mentioned amps.

 

[Trell]

what a joke! i believe objective reasoning to a point, but i still have not heard about any measurements that determine instrument separation and soundstage, and without moving position of speakers or changing anything but amplifier, i have heard DRAMATIC differences by amp alone, with Pass Labs and Mcintosh having the best in this regard out of about 30+ amps i have tried... People can believe whatever they want about objective measurements, but until i hear about any measurements thtat actually determine how well instrument separation and soundstage is, i believe in both objective and subjective impressions, and it is not just bias. Even my wife who never does critical listening, she immediately stated that when i introduced either of the 2 amps mentioned that she could hear a dramatic difference...and the other amps were not sleepers or junk or malfunctioning...some amps are clearly designed better....DACS i have heard some differences but not nearly as daramatic as when i go to one of the mentioned amps.

 

[mikemcsw]

i would slap my face too if i never heard a difference with different amps.

 

[Trell]

i would slap my face too if i never heard a difference with different amps.

It’s all in your own mind and the post you called a “joke” is spot on.

 

[DonR]

what a joke! i believe objective reasoning to a point, but i still have not heard about any measurements that determine instrument separation and soundstage, and without moving position of speakers or changing anything but amplifier, i have heard DRAMATIC differences by amp alone, with Pass Labs and Mcintosh having the best in this regard out of about 30+ amps i have tried... People can believe whatever they want about objective measurements, but until i hear about any measurements thtat actually determine how well instrument separation and soundstage is, i believe in both objective and subjective impressions, and it is not just bias. Even my wife who never does critical listening, she immediately stated that when i introduced either of the 2 amps mentioned that she could hear a dramatic difference...and the other amps were not sleepers or junk or malfunctioning...some amps are clearly designed better....DACS i have heard some differences but not nearly as daramatic as when i go to one of the mentioned amps.

The real difference is found in cables. Once you start spending 4 or 5 figures on the bits of wire that connect, you start to hear all manner of things that have secretly been hidden from you all these years.

 

[mikemcsw]

The real difference is found in cables, once you start spending 4 or 5 figures on the bits of wire that connect, you start to hear all manner of things that have secretly been hidden from you all these years.

I never heard a fidelity difference with any cables and i don't believe that, but I feel sorry for anyone that has never heard a difference in an amplifier and considers themself an audiophile....

 

[mikemcsw]

It’s all in your own mind and the post you called a “joke” is spot on.

I guess you use a $50 plastic amplifier then to pair with your $10K speakers....enjoy your listening pleasures mr audiophile.

 

[DonR]

I never heard a fidelity difference with any cables and i don't believe that, but I feel sorry for anyone that has never heard a difference in an amplifier and considers themself an audiophile....

As mentioned, separation and soundstage are ALL in the speakers and room treatment. A simple double-blind test would confirm this. The amp would have to be extremely poorly designed to affect these aspects of reproduction and I can confirm that examples of such exist all across the price range. The build material of the amplifier is immaterial here.

 

[Trell]

I guess you use a $50 plastic amplifier then to pair with your $10K speakers.

You do know that amplifiers are not made of plastic but has a lot of metal in in? Do you believe that interconnects and speaker wire is made of plastic to?

 

[mikemcsw]

As mentioned, separation and soundstage are ALL in the speakers and room treatment. A simple double-blind test would confirm this. The amp would have to be extremely poorly designed to affect these aspects of reproduction and I can confirm that examples of such exist all across the price range. The build material of the amplifier is immaterial here

If that was true, by simply swapping out the amplifier you would never hear a difference...I feel sorry for so many people on this site that have never heard any differences in amplifiers.....the differences can be very dramatic, that even someone with bad hearing could easily hear the difference...clearly some people have never owned a decent amplifier that believe this nonsense....you can own a used amplifier for under $100 that would measure within the audible range", so i guess everyone that spends more than $100 on an amplifier is stupid....

 

[Doodski]

If that was true, by simply swapping out the amplifier you would never hear a difference...I feel sorry for so many people on this site that have never heard any differences in amplifiers.....the differences can be very dramatic, that even someone with bad hearing could easily hear the difference...clearly some people have never owned a decent amplifier that believe this nonsense....you can own a used amplifier for under $100 that would measure within the audible range", so i guess everyone that spends more than $100 on an amplifier is stupid....

Over several years I compared thousands of Luxman, Harman Kardon, Yamaha, Sony, Technics, Pioneer and Mission amps and receivers with instant switching capability on low end and up to ~$2500 speakers in a sound room and at low to low medium volumes the sound is virtually identical to each other except for some entry level Sony receivers using STK amp IC's. We did blind testing so that we could not cheat and be influenced by our bias(s). When getting into the more difficult load speaker types a more expensive high current capability amp is req'd as we know and in that category I've heard a couple that sounded different and that again was at low to low-mid volume levels. Of course for headbanging rocking situations we obviously need lots of power but we are chatting about sound quality not quantity. Have you been doing blind listening tests?

 

[mikemcsw]

You do know that amplifiers are not made of plastic but has a lot of metal in in? Do you believe that interconnects and speaker wire is made of plastic to?

not worth responding to...

Over several years I compared thousands of Luxman, Harman Kardon, Yamaha, Sony, Technics, Pioneer and Mission amps and receivers with instant switching capability on low end and up to ~$2500 speakers in a sound room and at low to low medium volumes the sound is virtually identical to each other except for some entry level Sony receivers using STK amp IC's. We did blind testing so that we could not cheat and be influenced by our bias(s). When getting into the more difficult load speaker types a more expensive high current capability amp is req'd as we know and in that category I've heard a couple that sounded different and that again was at low to low-mid volume levels. Of course for headbanging rocking situations we obviously need lots of power but we are chatting about sound quality not quantity. Have you been doing blind listening.

I am glad you are convinced. I am convinced differently. I also question your statement of comparing "thousands", especially with such critical listening, and even if you are in the business, and if i can discount even one part of your statement, i questions anything you say.
Regardless, even if you did compare thousands, i feel sorry for your ears not to be able to easily tell the difference...and I honestly believe you should consider a different hobby.
You shouldnt even need to do "critical listening" to hear soundstage open up...to me it is like night and day between Pass or Mcintosh as compared to some other amplifiers. I am sure there are other good amps besides Mcintosh and Pass labs, but to me those are the ones i have tried that i was able to easily hear a difference, by not changing out anything but the amplifier.

 

[Doodski]

not worth responding to...

I am glad you are convinced. I am convinced differently. I also question your statement of comparing "thousands", especially with such critical listening, and even if you are in the business, and if i can discount even one part of your statement, i questions anything you say.
Regardless, even if you did compare thousands, i feel sorry for your ears not to be able to easily tell the difference...and I honestly believe you should consider a different hobby.
You shouldnt even need to do "critical listening" to hear soundstage open up...to me it is like night and day between Pass or Mcintosh as compared to some other amplifiers. I am sure there are other good amps besides Mcintosh and Pass labs, but to me those are the ones i have tried that i was able to easily hear a difference, by not changing out anything but the amplifier.

That's all fine and dandy but have you been doing blind level matched tests?