Should Subwoofer Be Plugged Into Same Circuit?

@lewinskih01

I have no particular knowledge of the technical characteristics of electrical noise that can be generated by LED lighting, although I understand that it can be significant. I found the following writeup, though, which indicates that the amount of noise can vary drastically among identically rated LEDs, depending on the manufacturer and how they have implemented the design:

https://healthybuildingscience.com/2013/09/10/emi-and-leds-not-all-leds-are-the-same/

Best regards,
-- Al

@craigert, being familiar with Ieales’ posts I can vouch for the accuracy of analyses he provides. Also, given the equipment in your system that you’ve listed in another thread, namely:

Sony OLED TV, Marantz preamp processor, Atoll amp, cable box, nighthawk router, Xbox, Rega P3 TT, and powered 12” subwoofer with 2 stereo speakers.

... it seems safe to assume that a 15 amp circuit and 14 gauge wiring of reasonable length (e.g. 50 or 75 feet or so) would be suitable for powering your equipment.

Of course installing a 20 amp circuit can’t hurt, and conceivably could provide added flexibility in the future. I would be more concerned about the drop of a volt or two or three that would occur due to the resistance of that wiring (depending on the current drawn by the components as well as the length of the wires) if a tube amp having unregulated filament (as well as high voltage) supplies were involved. And there are some very high powered solid state amplifiers which can require a separate 20 amp circuit even for each of two monoblocks, but those are big, heavy monsters which typically are at the extreme upper end of the price spectrum. Different animals altogether.

Regarding the possibility of adverse sonic effects from GFCI or AFCI/GFCI outlets, I have no particular knowledge. FWIW, though, my instinct would be to doubt that there would be any adverse effects. For one thing, if significant voltage was being dropped in their contacts they would be heating up significantly.

Best regards,
-- Al

... why is a 20 amp circuit recommended over a 15 amp out of curiosity?

My understanding is that 15 amp circuits are often wired with 14 gauge conductors, although they can be wired with 12 gauge, while 20 amp circuits must be wired with 12 gauge or larger. For a given amount of current 12 gauge will of course produce less voltage drop in the conductors than 14 gauge, resulting in a slightly higher voltage being supplied to the components. (Although if the line voltage that is supplied to the particular location is near the high end of its +/- tolerance less voltage drop in the conductors could conceivably not be preferable, depending on the design of the specific components). Also, of course, with a 20 amp circuit and breaker there is less chance of overloading the circuit and causing the breaker to trip, for instance if the power amp and/or the sub draw large amounts of current for significant amounts of time, during high volume musical passages.

@lowrider57
... correct me if I’m wrong, one of the receptacles needs to be grounded to the service panel, not self grounded. If there are two separate runs of Romex, then both need to be grounded to the panel to help prevent a ground-loop. This may also lower the noise floor.

I think your words "not self grounded" are referring to the fact that it is preferable for the safety ground wire to not be connected to metal conduit at the outlet, and that is correct per my understanding. Regarding that also see page 191 of the reference I linked to earlier, which discusses "isolated ground" receptacles. Note that using Romex to connect to a non-isolated ground receptacle accomplishes that by its nature, since there is no conduit.

And of course neutral and safety ground for all runs must be connected together at the main service panel, and they should be and hopefully will be connected from there to a nearby earth ground.

Best regards,
-- Al

My guess is that you'll be ok plugging the sub into a different outlet than the rest of the system, on the same circuit. Assuming (per the reference cited in my previous post) that the wiring between outlets is Romex or some other wire type which has the safety ground conductor symmetrically placed between the two current carrying conductors, or alternatively has them all twisted together.

The only way to know for sure, though, is to see how it works out, as susceptibility to ground loop issues is also very much a function of the design of the specific components.

Best regards,
-- Al

To add to the foregoing comments, I suggest that you read pages 31 through 35 of the following document, the section that begins with "this finally explains what drives 99% of all ground loops." It was written, btw, by Bill Whitlock, a renowned expert on such matters.

https://centralindianaaes.files.wordpress.com/2012/09/indy-aes-2012-seminar-w-notes-v1-0.pdf

As you’ll see, the type of wiring can dramatically affect susceptibility to ground loop issues. Romex (i.e., NM cable) is pretty good in that respect. The worst case in that respect is discrete wires randomly positioned in conduit.

My thanks to member @Jea48, this Forum’s foremost expert when it comes to electrician-type matters, for calling this paper to our attention here a few years ago.

Best regards,
-- Al