Wifi interference on speakers?

If it persists even when muted and is volume independent then this implies it is being picked up in the circuit made from speakers to amp and not caried via the interconnect. Can you:

1. Confirm the problem persists when wifi is enabled but the streamer is disconnected?
2. Clarify where you speaker cable slack is located and how it is gathered? Is it bunched,  or coiled and if so, near the amp (how many cm)?

If breaking the connection from streamer to amp resolves the issue, maybe look at the quality of the earthing and how it is set (if a naim streamer, there should be a switch to set this to chassis). A set of ferrite cores on the interconnect at the amp end may help (certainly they shouldn't hurt). If breaking the connection has no effect then it means the circuit betwen amp and speakers is acting like an antenna and picking up the tranmissions from the streamer (it may be receiving but it has to constantly communicate back to the access point so is constantly transmitting too).

But in answer to your first question, no, I've never experienced this.

Hi, some sort of wifi RF coupling into the speaker leads is possible, although feels unlikely given the frequencies involved.. Try moving your speaker leads around to see if it changes...

However I suspect its noise from the wifi module in the SU.. perhaps conducting through internal the SU Power lines. So if moving the speaker cables around or even trying with headphones if you can makes no difference, I would speak to your dealer to ask them check the unit for you at their shop to see if the noise is still prevalent .. If it is it might need to go back to Naim.

Thanks FZ, problem indeed persists when both bi-amp speaker cables and interconnect disconnected from SU, albeit fainter still. Reappears as before when reconnected.

Not much speaker cable slack, no bunching at all - heavily shielded Chord Epic Super Twin bi-wire used to bi-amp SU and NAP 200 DR to PMC 23's.

I should add that the interference is completely inaudible when playing music from any source and, to my ears, does not impact SQ whatsoever. In fact, if I hadn't happened to be sitting next to a speaker tinkering with iRadio stations on the Naim App on my iPad, I would never have heard it at all.

I am inclined to see if the effect can be reproduced on the dealer's demo SU before moving to repair/replace, as it is most probably exactly what Simon says, RF leakage from the wifi module.

Thanks both, KR, J

Ahh the plot thickens, there is another power amp involved. 

I would definately follow Simon's line of thinking and see if the interference is being transmitted through the mains. An extension cord to another socket on a seperate mains rung will help confirm/eliminate that.

As with any troubleshooting, keeping things simple is best. if you can test without the 200, then do.

Finally, my ears pricked a bit when you mentioned shielded speaker cables. A shield without a drain (earth) can cause more RF problems than it prevents. Hence most speaker cables aren't shielded. If you can borrow something simple and unshielded like A5 for a day, it may be worth it.

Once you figure out which of the variables impacts the problem, you can then spend more time formulating what to do about it.

So the plot thickens a little more.

If I remove the wifi antenna, then the interference disappears. And rotating the wifi antenna through 90 degrees, until it is pointing horizontally away from the SU chassis virtually eliminates the effect, the faintest of faint interference remaining.

Unless I am mistaken, this appears to point to environmental directional coupling or re-radiating RFI  through the speaker/interconnect/mains cables, resulting from normal, not faulty, wifi operation, which could prove very difficult, time consuming and expensive to wholly eliminate?

Anyone care to suggest alternatives? Would the WA-5 offer any improvement perhaps - higher gain, lower power transmission?

KR, and thanks again to all, J

ok - given the new info - and the sensitivity of Naim power amps to speaker cable - i.e. best to use their own cable - I would swap out and use Naim speaker cable or borrow from your dealer - I suspect that will nail it

Simon

If you have to use WiFi I would use an Airport Express or similar external device connected to the SU with a patch cable, rather than the poor 802.11g built-in WiFi module that Naim streamers use. This should give you better performance, and means you can ditch the offending antenna permanently. By doing this, you are, of course, adding another SMPS near your system, which is a potential issue in itself, but overall, I found this to be a useful move before I switched to a full wired network. 

Chrissu, did you configure your AE to 'extend' or 'join' your wifi network? KR, J

I have 2 AEs, both set to 'extend'. I need these as my house has two thick stone internal walls, and the Airport Extreme connected to my router just can't manage to reach all over the house. An added bonus of having an AE near your streamer is that in addition to the Ethernet connection, you can add an optical connection which gives you Airplay should you need it.

Chrissu, AE installed to 'join' network to minimise bandwidth impact, hard wired to SU @ 300 Mb/s, and NO wifi RFI in the background, only 'inky blackness'! Many thanks. KR, J

Glad to hear you're sorted. It's been so long since I configured my network that I can't even remember what the difference is between 'join' and 'extend'! But was long as it works, who cares 

And, networking trivia point, the SU only appears to broadcast a DHCP request over the wired connection once, when it is powered up?

KR, J

Dr_J posted:

And, networking trivia point, the SU only appears to broadcast a DHCP request over the wired connection once, when it is powered up?

KR, J

That's what is supposed to happen with DHCP.  If/when the router expires the lease, then the SU will be told by the router that the lease has expired and the SU will broadcast another DHCP request for an IP address.

best

David

Thanks David.