Rel sub cable

Hi-Fi Corner
22

The high level connection is 150,000 ohms.

23

And a 150k ohms is going to put zero stress on any amp. My suggestion is if anyone has any questions call REL and ask them. I suspect they know more about their products than anyone here.

24

@toonfan As I mentioned just follow REL’s setup guide. Who’s going to know more about a REL the manufacturer, or ?

I can tell you for sure not to miss the “Phase Setup” very simple to do but very important.

Good Luck.

1 Like
25

Rel suggested the phase will probably have to be set on 180 due to how the transmission line speakers work, I have Pmc twenty25-23 speakers, my stackable banana plugs should be here tomorrow, and I will go ahead and connect the hi level cable that comes with the sub to the speaker terminals on the nova, I thank you all for taking time out to reply to my question

26

Follow REL’s phase setup it’s actually very simple. It very well maybe that out of phase will sound correct, but still check.

27

150k + capacitance!

It’s the capacitance that destabilises / stresses power amps - look at the Niquist plot (or Bode plot) and see how that varies with capacitative loads! If you don’t understand the principles, please don’t give misleading information.

Whether or not it damages an amp is, as I said, a different matter.

28

If using an n-Sub this is as it should be (relatively small difference), because the amps are so similar, so the pre-amp level connection is viable. Main issue with pre-amp level is the pre-amps ability to drive a long interconnect, once why Naim had to slug their own i/c.

1 Like
29

It probably won’t cause any damage but it can cause issues as was documented in several threads on the old forum with users connecting from the back of power amps or NAITs and experiencing reduced performance or humming/buzzing. This was solved by connecting from the speakers.

2 Likes
30

The phase delay necessary depends on the relative position of the main speakers and the sub, the method of connection and the group delay of the sub. The required phase delay can vary from 0° to 359°.

31

The phase adjustment on a REL sub and most Good subs is simply 0 or 180 degrees The only thing one is is doing is making sure the Subwoofers driver is moving in phase with the main speakers, no more no less.

32

@Xanthe BTW how much capacitance do you think a simple 18awg copper wire
20 ft long actually has, very very little about 16.5 pF/ft

33

That’s handy to know. Thank you for sharing.

34

The input impedance on the Rel is 150k ohm.

35

I joust did the maths and the Rel + 4 ohm speaker has a total impedance of 3.99989 ohms. How would this “stress” the amp?

36

And no capacitance at all, not even a connector or an internal cable connecting it to the amp input, and no interconnect cable (all these add capacitance)? So just 150k of pure resistance? As I pointed out earlier, it’s not the resistance that stresses amps, it’s the capacitance.

Look at the effect of capacitance on the Niquist plot or the Bode plot; then you’ll see the problem (always assuming you know how to interpret these diagrams, and if you don’t, then you don’t understand how amplifiers work and aren’t in a position to comment!).

37

Which is why for appropriate positioning of a sub (to minimise excitation of the fundamental room modes) and then be able to minimise phase shifts through the crossover region, it’s necessary to have the sub closer to the listener than are the main speakers, and may also require a DSP to trim the phase to something other than 0 or 180.

38

You’re 100% right Xanax! Party on!

39

Who cares? This isn’t the 1950’s and op isn’t building a HealthKit hifi. He just wants to confirm that it’s okay to to hook up his Rel directly to his Nova. The answer is yes. But you EE types just have to chime in with “but it will put additional stress on you amp” bs that just leads to fear, uncertainty, and doubt. Not once in the past eight years has anybody posted issues re Rel & modern Naim integrated amps. This additional “stress” is just theoretical and unlikely to have discernible impact on sq

1 Like
40

I should have gone with my gut feeling and used the supplied cable and saved myself over £100, my thinking was, in regard to connecting to the speaker terminals on the nova, or the speaker terminals on the speakers, if the Rel cable is connected to the speaker end, is it not still going to effect the amp, it’s forming a circuit back to the amp isn’t it ?, I thank you all for the help and advice, if somewhat conflicting at times, enjoy your day guy’s

41

@toonfan what did you buy for 100. ? Yes the supplied stock REL cable is fine. Yes the best way to hook up the sub is to follow REL’s instructions. I’m sorry if I contributed in anyway to your stress. Enjoy your REL :grinning_face_with_smiling_eyes: