REL volume level with Naim system

Hi all,

My current system setup is Naim dac+200+202+dynaudio contour s1.4 with 2 new added REL t9x. I connected the t9x to the back of the speakers with red cable and black cable only, leaving the yellow cable hanging. Since I found the volume is too high for the sub by twisting red and yellow cable together.

Rel recommended the crossover and volume to be 15 clicks from the minimum. However, I found that by doing so, the sound is twisted with hard mechanical hitting sound, with the amp volume level tuned at about 10 o’clock when watching movies. I believe that is sound of the sub being bottomed out. Therefore, I tuned the volume of the REL to 8 clicks instead of 15. That’s when the hard mechanical hitting sound disappear. My NAIM amp is usually at 9 o’clock.

I wonder what are you volume levels for the REL and the NAIM amp?

Many Thanks!

I assume you have watched all the Rel videos on their website if not well worth while.

I connect my Rel to the 552 power supply and have settings at 10 for crossover and 15 for line level.

Reading some comments on FB plenty of people have settings way different to the 15 +/- 3 that Rel talk about so experimenting is worth while albeit a faff……



Welcome to the forum BTW! Plenty of Rel users about so hopefully others will chime in with their experiences.


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Every system has its own settings, and REL’s guideline is meant as a basis to start with. Where REL recommends both xover and gain to be set at 15 clicks, I believe that is just for the first part of setup, where you determine phase. Then you typically lower the xover point, how much depending on speakers. Offhand 15 clicks for both seems too high to me. I had a pair of Controur S1.4, and they have pretty good bass for a standmount speaker. I used a single sub with them and am positive I did not set the xover that high.

I have a pair of REL R-328. My xover is set to dead bottom (30Hz I thjink) and the gain is 9 clicks. I have the new S/510 on order and will see how those integrate. I may try the same setting to start with, and work from there to get them dialed in.

With REL subs the rule of thumb for better and well-integrated bass is lower xover and higher gain, vs the other way around.


Best way to set up a sub is using REW software (free) with a measuring microphone (cost around £110, or from about £60 secondhand, and easily re-sold if you don’t need it anymore. That will help with frequency cut-in, level, and phase. (It can also greatly help assess best speaker and listening positions in your room, and help identify room problems.)

The level to match the sound from main speakers will depend on the sensitivity of those, and on room factors.

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[quote=“Innocent_Bystander, post:5, topic:27028, full:true”]
Best way to set up a sub is using REW software (free) with a measuring microphone (cost around £110, or from about £60 secondhand, and easily re-sold if you don’t need it anymore. That will help with frequency cut-in, level, and phase. (It can also greatly help assess best speaker and listening positions in your room, and help identify room problems.)

The level to match the sound from main speakers will depend on the sensitivity of those, and on room factors.

I’m not very technical minded so have not explored the REW software but prob should. May do some research at the weekend as plenty of people recommend it.


Thank you so much for your kind reply! I wonder what is your volume level for the Naim Amp?

Thank you so much for your reply! It helps a lot, especially knowing you are using S1.4 as well. What is your current speaker? And what’s the volume level on the Naim amp? When you are using a pair, do you lower the volume by half for each?

Many thanks for suggesting measuring and tuning in a solid scientific way. Any thoughts on using a phone app compared to using a measuring microphone? I believe nowadays the phone apps have good algorithms to compensate the sensitivity of the measuring microphone? Any suggestion on what sound track to measure? pink noise or frequency sweep?

I did some test… which setting would you recommend? I used logarithmic sweep from 20hz to 20khz. X means crossover, v means volume for 2 RELs at the same setting. It looks like volume 8 gives me the same level with the main speakers. However, it is not very sensitive to the crossover settings.

No subs:

Suggested setting from REL, clearly it is too much bass.

Sorry for multiple posting…It looks like the forum only allow 1 pic for new users…
It looks like volume of 6 is a little bit low…

Ended with this, Volume 8 gives the similar volume as the main speakers. But it looks like there is still a dip at 100. I don’t think I should go any higher on the crossover… Any thoughts? Tried crossover from 6 - 20, it is not that sensitive. Probability each click is too subtle, given 40 clicks ranging from 30hz to 120hz. Each click only tuned about 2.25hz. So 20 clicks is about 75hz.

in my setup I am about 5 clicks on Xover and 5 clicks on Gain. Any louder and it booms. Walls area concrete though and the Olympica Nova 3s are not bass shy to start with.

The purpose of a sub is to fill in the lowest octave or two below wherever the main speakers start to roll off. The specification of the Coutour S1.4 claims it is 3dB down at 40Hz, which seems to be consistent with the response in your room unsupported by the sub, though that is looking at the yellow plot, the red showing roll off from just below 50Hz - I don’t know why there are two plots: what is each supposed to represent? However it looks either as if that phone app doesn’t have a level response below 40Hz, or the sub’s output is very poor where it is needed. I would suspect the phone app, so it would seem it isn’t suitable for this.

You want the sub to be coming in just where the Contours start to roll off. The X15 shows boosting at 62Hz which suggests a lower crossover setting needed, but it is not easy to be sure without a level microphone response in the bass region going well below 40 Hz, and impossible to tell anything about required volume setting.

I don’t have experience with setting up subs myself. A person who has and may be able to advise better is @Xanthe, using miniDSP as a tool to tailor.

All right…Problem solved…after setting the crossover to max (120hz), the dip around 100hz is gone. Conclusion: 15 clicks for both crossover and volume is a very far starting point.
REL suggests it is a common mistake to set the crossover high with the volume
Lesson learnt: Don’t be too shy to max out the crossover.

I assumed you wanted to supplement the Contour’s output below its cutoff, however from your latest post I gather you are trying to remove a dip around 100Hz, which in turn suggests you are using the red plot not the yellow - though the yellow is the one that has certain frequencies picked out which, which together with yellow being the more visible one (I have to strain to see the red) led me to focus on the yellow.

But what are the two traces, red and yellow? The two are very different in response, yellow in your latest post showing a marked lowering of response below about 800Hz apart from that distinct peak at 322Hz, while the red is better though rolling off markedly below about 50 Hz (though I’m not sure the app is reliable at the bottom end.

My guess, the app is Spectroid on a phone or tablet. The yellow line is the current reading, the red line is the peak, so at some stage the volume for any particular frequency has hit a maximum. So possibly the dips around 100 Hz on the red trace are room cancellations? It might be worth putting the room dimensions in Amroc room simulator?

Great guess! You are absolutely right, the app is Spectroid, and the red line is the peak level. I used a frequency sweep as the source. What would you guess for the room cancellations? I have a large flat table between the listening position and the speakers. Would it be the reason? Here is the screenshot for Amroc room simulator. Any thoughts?

Okay, with frequency sweep the peak level – red line - is the signal, the yellow will be background noise with aproportion of the peak added in. That puts a bit of a different complection on things where I was looking at the yellow line which is the only one I can see clearly, and is of no value at all with the frequency sweep.

The app really does not seem to be much use below about 40Hz, which is just where you need it if you want the sub to do a normal sub’s duties of filling in the bottom end or see what the effect is there with your intended boost around 100 Hz.

As for the area around 100 Hz, your final settings do indeed appear to have improved that, though how even a response you get simply with a phone app is questionable. I’m not saying that the peaks/troughs or rolloff are artefacts of the phone, simply that I have no idea at all. (There is a reason why measuring microphones are normally used for this sort of purpose, having an essentially flat response across the whole audio band, with a calibration curve that is used to cancel out whatever deviations there may be.)

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