Connect Pre to Sub (RCA/XLR; Atom)


#1

Hi!

I’m considering adding a Sub to my Atom; as I understand, I can use the pre-out for this.
(I don’t think I want to look at the connection options via the speaker connects.)

I’ve had a look at a model, which offers both, an RCA and XRL input.

I guess the obvious is to get a RCA/RCA cable, and connect the Sub to the Atom this way.
Question: What’s recommended “maximum length” of such a connection? I guess, this depends on the quality/shielding of the cable; any ballpark figures say for a simple or moderate expensive cable?

As for the XLR: is there any use for that with the Atom? (I guess, without an XLR output on the box: no?)
So I should consider this a “connector to be considered for any future deployments”? (Not sure, if any Surround-Receivers have such connections, to e.g. connect the Sub to both systems in parallel?)

BR/Philipp


#2

I’m not aware of any information that Naim have released about the ability of the Atom to driva a sub via long interconnects, so I would suggest that you contact them directly and ask. If in doubt, the high level input is usually a safe bet.


#3

I’ve sent a request…
… the FAQ just mentions, that sub/power-amplifier are options (without details).


#4

Unfortunately, we do not have a recommended length of RCA/RCA cable to connect your Atom to a subwoofer.

(…)

We’ll, maybe I’ll talk to my potential dealer and/or just assume “decent lengths” must be supported. (Otherwise the option would not be mentioned?)


#5

That looks like a bit of a halfarsed reply to me. When Naim made a sub, they were quite clear in the manual (remember them?!!) that care should be taken selecting a low level interconnect “to protect the preamp from the high capacitance inherent in the necessarily long lead.” If your reply came from somebody in the same building where your Atom was designed and built, surely they can answer a basic connection about how to use it for its intended purpose?


#8

(…)

Ah, yes. This sounds more like a typical IT support answer within the company I work with (after series of outsourcing and cost-cutting on internal IT support - which is deemed a cost item mostly) than an engineering answer from a company dedicated to quality products and support. :wink:


#9

Maybe you could ask your dealer to press them for a better answer.


#10

Interested to know if you get a better answer from Naim … my dealer was a bit stumped when I asked about sub connections,

I connected a sub to my Atom via spare 1m RCA interconnects I had lying round (in fact I’ve got both cables plugged into the Atom, not sure if that’s necessary/correct but nothing’s blown up yet) into the low level sub inputs. Sounds great.


#11

I’ll check with my dealer.

For a 1-meter connection I would not bother - that must be “okay”, if you want to connect to a sub standing on the floor. In my case it might up to 4-5 meters, depending on where I would “squeeze it in”.

As for connecting both parts of the RCA: from what I read, you should definitely do so. The RCA-out on the Atom is stereo - so for the sub to process both left and right channel (extracting the low frequency parts), both need to be connected.
(This is opposed to having a sub running in a A/V-receiver setup, where the receiver does a low-frequency-effect (LFE) mix specifically for the sub considering whatever is marked as LFE in the original x.1 source plus whatever its DSP might want to put there. The A/V-receiver will then output a mono signal to the sub.)


#12

Good info - thanks very much. Hope you can get some proper insight into max cable length.


#13

I connected a single 3 meter subwoofer cable to the left pre out socket of my UQ2 with no issues.


#14

Naim’s own sub lead (DIN4 - 2 x RCA Phono) came in two lengths - 5m or 10m. IIRC it used lavender/grey i/c cable and in both cases the lead was slugged with a 100R resistor to prevent possible instability, mainly because the pre-outs in the PSUs were never originally designed to drive such long i/cs.

Since then there have been Naim products with specific “Sub OUT” RCA phono sockets that have been designed to drive a subwoofer lead without the need for a resistor “slug”. It may well be that the pre-out on a Uniti Atom is similar here, but probably worth checking to be certain. Either way, your sub lead should be low capacitance and I would try to keep it as short as is practical for your needs.