I’ve done some research regarding adding a sub to my 250/52/Supercap setup. I have a pair of Harbeth SHL5’s, and although I’m very happy with them I’d like a bit more bass at lower listening levels. The Rel T series seem to get good reviews so I had a look at the manual with regard to connectivity.
Rel state that I can connect the sub direct to the speaker outputs on the power amp. However, I’ve seen in this forum that this is not advisable for Naim amps, although I can’t see a reason why. Can anyone explain?
So if I can’t use the power amp then my next connection option would be to connect directly to the speaker terminals, using red and black for one speaker and yellow for the other. My speakers are about 10 feet apart, where can I source an appropriate cable?
I’m a complete newby regarding subs, so any other advice would be welcome.
TIA.
Welcome to the Fourm Tony. In case you were unaware, the forum has a pretty decent search facility, which you may find useful as this has come up many times previously.
In a nutshell, if you connect two things to the speaker outputs, it changes the load the amp sees and it may get upset. An exception to this is REL’s Bassline Blue sub cable, which is compatible with Naim amps and lets you connect to the back of the amp. If you choose to connect to the speakers you can use twin core mains lead, connecting two cores to one speaker and one to the other. Obviously both speakers need to be connected. No need for anything fancy.
I would just add that it’s the Naim specific variant of the Bassline Blue cable you need, not just the regular version.
There is also a much cheaper version of this cable available from Designacable.
FYI. Alan Shaw of Harbeth hinted that a subwoofer was in the works.
I can’t imagine the upcoming subwoofer from Harbeth to be as versatile as a REL, KEF or SVS subs though, so looking at your setup connecting to the terminals (speaker or power amp) it surely is the only way to go. I’d probably look at a sub which allows you to use a high-pass filter which in some cases will allow an easier integration into your system. With low-pass you are basically counting on a bit of luck to make it all work.
I found that the options to connect a sub are not straightforward, so take your time in reading about the different options available to decide what suits you best. There are plenty posts in the forum.
I decided to go against the high-pass filter in my system because having additional speaker cables hanging around between the components is not really a sight to behold…
I am a bit surprised that you feel the need for a subwoofer with the SHL5. I suppose you have already optimized speaker placement to get a more bass in your room?
I have removed the link. Please respect and abide by forum rules. Thanks.
Connecting directly to the speakers works absolutely fine and also avoids the high cost of the BassLine Blue cable (and it’s weak stackable banana connectors). All you need to do is split the supplied cable. The handbook shows which cables to connect where. Works a treat in my system with no negative side effects at all.
That’s certainly the cheapest solution as it uses the cable supplied with the sub. Probably also the best way if your sub is reasonably close to the speakers, but not so much if it’s on the other side of the room.
The supplied cable (with mine, at least) was a good 10m long, so it shouldn’t be a problem unless OP lives in a converted church!
Still a potential eyesore or trip hazard in some rooms.
Many thanks for all the replies. Some food for thought there. I’m liking the idea of using a Rel with the Designacable version of the Bassline so I can connect directly to the power amp. I’ll have a think and do a bit more research, maybe see if I can borrow a sub from somewhere. Thanks again.
I have a 252/SC/250 set up, so similar to you. I use a single Totem Storm sub, which is wired direct off the second output on the SC, using a Din to RCA cable. My speakers are Totem Forest Signature, so I went with the Storm as the natural combination - being designed to be used with the main Totem speakers. It all works very well in my set-up.
T series are not recommended for the Harbeth SHL5. On REL’s subwoofer pairing guide, the S812 is the minimum requirement. You can still try the S510 but I wouldn’t drop to the T series if I were you.
FWIW I have the SHL5 Plus and REL S510 but the sub is currently used with the Marten Duke 2 in the main system. I haven’t tried the REL with the SHL5+ yet.
I have a REL S/510 with ProAc’s , setup right it will make a huge difference. If it’s too much $$$ a REL T/9X would work fine. Also I’d just split the OE REL cable and tap off the speakers, much simpler than trying to hook up to the Naim speaker outputs.
Was wondering if adding REL subwoofer would stave off the desire for a speaker upgrade. However the REL site recommends a pair of S/510 which would take us (with trade in) almost to a pair of Kudos 606!
So no quick win 
Many thanks for pointing this out, I hadn’t realised.
I would like to use a REL T/7x with my NAP 500, but don’t quite understand how the Designacable works in that situation.
Can anyone enlighten me?
Never mind.
Finally found the answer on Designacable’s website. Thanks!
Presumably you are aware that the 500, being a bridged design, has slightly different connection requirements to other Naim amps?