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Sonos Amp and High level input from Subwooder?

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K

Not sure I want to get 2 Sonos subs in the same room, that’s why I tried something different with the Def Tech 800 and was considering a Rel Sub.
Even if Sonos Sub gives better results than the Def Tech in both high and low level mode? Because chances are that the REL will not do much better than the Def Tech.
Of course, the best would be to try everything and then decide!
K

Ok so just to make it clear, should I just keep the sub plugged into the Amp sub port and not worry about the high level? Just wondered if I’d get a better music experience, not that it’s lacking now
Why don't you see what happens if you connect the high end inputs on the Sub to the speaker terminals on the amp? Some experimenting with the Sub cross over may be needed keeping in mind how deep your main speakers go with enough energy, but all it will cost is time.
By the way, from one of your posts I got an impression that you got better results with the Amp using the Sonos Sub bonded to it. No?
R
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Ok so just to make it clear, should I just keep the sub plugged into the Amp sub port and not worry about the high level? Just wondered if I’d get a better music experience, not that it’s lacking now
Why don't you see what happens if you connect the high end inputs on the Sub to the speaker terminals on the amp? Some experimenting with the Sub cross over may be needed keeping in mind how deep your main speakers go with enough energy, but all it will cost is time.
By the way, from one of your posts I got an impression that you got better results with the Amp using the Sonos Sub bonded to it. No?


I will have to try it out, and test the Sonos sub again as well. Not sure if it was better or similar, just had a brief test and liked it enough to get a separate sub.

I’m using banana plugs, so I will try to put the sub to the amp first, and the 2 speakers connected to the Sub instead of crossing both at the amp end, wonder if that will work well with the amp
K

I’m using banana plugs, so I will try to put the sub to the amp first, and the 2 speakers connected to the Sub instead of crossing both at the amp end, wonder if that will work well with the amp
No no no. For it to be meaningful the speaker terminals of the amp have to be double wired. To both the main speakers as now, and also to the high level left and right terminals on the Sub.
Your way will deny the main speakers of the low level content that will be stripped out by the Sub crossover. Unless the Sub, as a few do, allows a full pass through of the signal.
K
For your evaluation remember that with the Sonos Sub, you can select the crossover that is most suited for the main speakers in use. If therefore your speakers already do a decent job of bass delivery, set the crossover on the Sub at the lowest - 50/60 hz if the speaker pair goes down adequately till there. This then will be very close to what high level connections are supposed to do, allowing the main speakers to do as much as they are capable of doing, and the Sub only for frequencies lower than that. Unfortunately, this choice is not available for third party subs where the crossover can be set to only 80hz.
Also, best results are obtained when the Sub is placed between the two main speakers, in the same plane. While centre position is ideal, offsets to either side to an extent do not make an audible difference, if the central position is not available. For movies, Sub placement isn't so important, but I have found it to be so for music. A Sub away to one side of the speaker pair certainly isn't good for stereo imaging and integration with the front speakers, for music sound quality.
Finally, if you are setting the crossover at the 50-60 hz levels, make sure that the content goes below that with some emphasis on the lower frequencies, else the Sub won't be doing much that is heard/felt.
R
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I got the Rel sub.

to clarify, I have a Sonos Amp, and a Rel t5i subwoofer that lets me connect either via high level input, low level input, or .1 LFE


LFE gave me more vas’s, low level I could barely hear the sub. Have not tried high level yet

Here was my question, rephrased again:

What is the best way to connect to the amp? For music only

1. High level input where I connect my main speaker cables together with the Rel sub supplied left/right cables together on the amp

2. Low level input, Rca mono cable from sub out on amp to Rel low level input

3. LFE from amp sub out to LFE input on Rel
K
REL suggests 1, but it is easy enough for you to decide after trying all. After all, you will be the one listening to it long term.
R
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REL suggests 1, but it is easy enough for you to decide after trying all. After all, you will be the one listening to it long term.

I connected it via the high level connection, and it seems to work best. The low level I would barely get any bass, and the lfe I'd get bass but not sure how optimized it was for music.

I connected all wires at the amp side, and the black ground from the Rel on the negative on the amp as well. They recommend to connect the LFE connection just to ground it better and avoid a hum, which I did, and seems to work.

It's definitely a bit of a complex way to make a connection, but I think it works for the little listening I did today.

Now what's confusing me is the Sub advanced setting in the sonos app - do I leave it on, or off? I thought the cross over would be taken care of by the sub itself via high level, but I did notice some more bass when the sub is on in the settings. Of course LFE is connected but volume on the sub is set to 0, so it's just a ground.
K
If you are using high level, there should be nothing plugged into the Sub out jack on the Sonos Amp; doing that will strip the lower frequencies from the speaker terminals. And if nothing is plugged into that jack, nothing you do in the Sonos controller app to the Sub will make any difference.
What does REL recommend connecting their LFE jack to?
R
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If you are using high level, there should be nothing plugged into the Sub out jack on the Sonos Amp; doing that will strip the lower frequencies from the speaker terminals. And if nothing is plugged into that jack, nothing you do in the Sonos controller app to the Sub will make any difference.
What does REL recommend connecting their LFE jack to?

In order to avoid "hum", they recommended to connect the sub out to their LFE, and just put the LFE on the sub to 0. Apparently this helps ground the system. I was getting some hum before I did this, and now it's fine.

So no danger connecting both the LEF and high level with a ground to the speaker neg terminal on the amp right? Seems to be working fine, just want to avoid any shorts or issues.

So the Sonos app sub settings will only control whatever is connected to the sub out amp correct? It did seem to have some effect, even with lfe turned down to 0 and high level being used.

I tried to use the low level output on the sub to the sonos sub amp first, with a mono rca cable, but I would get very low bass - only lfe and high level gave me the right levels. Any idea as to why that is? Volume and crossovers were the same as is working on the high level
K


So no danger connecting both the LEF and high level with a ground to the speaker neg terminal on the amp right? Seems to be working fine, just want to avoid any shorts or issues.


I tried to use the low level output on the sub to the sonos sub amp first, with a mono rca cable, but I would get very low bass - only lfe and high level gave me the right levels. Any idea as to why that is? Volume and crossovers were the same as is working on the high level
The way the Sonos Amp is architected, anything plugged into its sub out will immediately strip out low frequencies from the speaker terminals on it, even if there is nothing connected at the other end. So using that socket is not to be done unless there IS a working Sub at the other end that will reproduce the stripped out frequencies. And even with nothing connected at the other end, the Sonos app will work on the connected Sub out jack on the Sonos Amp, but obviously nothing will be heard if there is nothing at the other end. But, as explained, the main speakers will be deprived of frequencies below 80hz, whether the other end is connected to a Sub which is left at zero, or there is nothing connected to the other end.

There is no danger in connecting a double pair of speaker wires at the Sonos amp speaker terminals - one set running to the main speakers and the other set to the high end inputs on the Sub. As to the ground connection to the speaker terminals on the amp, if you do exactly what REL has recommended, there should be no danger; with respect to what is happening at its speaker terminals, the Sonos Amp is like any other stereo amp.

I don't know why the low level connection from the Sonos Amp sub out jack to the low level connection on the REL does what it does. Maybe the user manual will tell you what needs to be done if that route is used.
R
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So no danger connecting both the LEF and high level with a ground to the speaker neg terminal on the amp right? Seems to be working fine, just want to avoid any shorts or issues.


I tried to use the low level output on the sub to the sonos sub amp first, with a mono rca cable, but I would get very low bass - only lfe and high level gave me the right levels. Any idea as to why that is? Volume and crossovers were the same as is working on the high level
The way the Sonos Amp is architected, anything plugged into its sub out will immediately strip out low frequencies from the speaker terminals on it, even if there is nothing connected at the other end. So using that socket is not to be done unless there IS a working Sub at the other end that will reproduce the stripped out frequencies. And even with nothing connected at the other end, the Sonos app will work on the connected Sub out jack on the Sonos Amp, but obviously nothing will be heard if there is nothing at the other end. But, as explained, the main speakers will be deprived of frequencies below 80hz, whether the other end is connected to a Sub which is left at zero, or there is nothing connected to the other end.

There is no danger in connecting a double pair of speaker wires at the Sonos amp speaker terminals - one set running to the main speakers and the other set to the high end inputs on the Sub. As to the ground connection to the speaker terminals on the amp, if you do exactly what REL has recommended, there should be no danger; with respect to what is happening at its speaker terminals, the Sonos Amp is like any other stereo amp.

I don't know why the low level connection from the Sonos Amp sub out jack to the low level connection on the REL does what it does. Maybe the user manual will tell you what needs to be done if that route is used.

Only issue if I unplug the Sub out from amp to the LFE on the Rel, the Sub gets a hum/vibration when music is off,and connected via high level.
K
I looked up the user manual online and did not find any reference to such a connection there. Where are you seeing it? When High level is used, per the user manual I found, the only connection from REL to amp is to its speaker terminals via the red, yellow and black cables at the other end of the REL supplied cable that has the speakon plug for use at the Sub end.
K
Further to the above, what happens if you let the black wire float, unconnected? If the hum goes away, properly cover the end of the black wire with insulating tape, and rollup/tuck it away out of sight.
K
If THAT does not work, what might is plugging a shielded RCA cable into the .1 LFE jack not to the Sub out on the amp, but into either of the two RCA input jacks on the amp. Via the shielding this should allow for grounding of the Sub to the ground of the Amp. I have not tried this myself, but seems to be a REL suggestion for amps that do not have a metal cabinet to which such a grounding can be done.
All the foregoing just shows how neat the Sonos Sub is; bond it to the Amp wirelessly with the app, choose the crossover based on how low the main speakers can go, and you are good to go. No worrying about high level/low level and grounding. If the sound is as good as REL, if not better, this begs the obvious question.
R
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If THAT does not work, what might is plugging a shielded RCA cable into the .1 LFE jack not to the Sub out on the amp, but into either of the two RCA input jacks on the amp. Via the shielding this should allow for grounding of the Sub to the ground of the Amp. I have not tried this myself, but seems to be a REL suggestion for amps that do not have a metal cabinet to which such a grounding can be done.
All the foregoing just shows how neat the Sonos Sub is; bond it to the Amp wirelessly with the app, choose the crossover based on how low the main speakers can go, and you are good to go. No worrying about high level/low level and grounding. If the sound is as good as REL, if not better, this begs the obvious question.

The only way I was able to get the hum to disappear while using the high level connection was:

Black ground to amp speaker negative
Rca cable from LFE on sub to the amp sub out


But this seems to make the sonos amp do the sub processing right? Can I by pass that by turning off the sub in the sonos options?


High level cable with no black ground or Rca connected gives me a very loud hum noise, I’ve tried it all ways and above was the only that worked

Also, low level input did not seem to work well, very weak bass when connected via Rca cable to the amp sub out. Why is that?

LFE sub out to amp sub in has proper volume and works, as does high level save for the hum. Why is low level not working?
K

The only way I was able to get the hum to disappear while using the high level connection was:

Black ground to amp speaker negative
Rca cable from LFE on sub to the amp sub out

This exactly what REL says you should not do, as far as the first part is concerned, where class D amps are concerned, and Sonos Amp is from that class.
As to the RCA cable from LFE to the Amp, REL says that a RCA cable can be connected to any RCA jack on the Amp that is free, it need not be the Sub jack only. Grounding is done via the shielding on the RCA cable so plugging the RCA cable to the line in jack on the Amp should also work.
Above two points as per REL videos on how to connect their Sub to an amp. If this is not working for you, I suggest you ask REL for help and return the Sub if they cannot solve the problem, subject to the next paragraph:
Plugging anything, even a blank plug into the Sub out signals the Sonos Amp to strip out the lower frequencies from the Amp speaker terminals. You cannot bypass that - all that turning the Sub off in the Sonos options does is turn off the Sub; this is a new feature and I suspect it does not restore the full frequencies to the speaker terminals. But there is no harm in trying this and seeing if it changes the overall sound quality in a beneficial way. I believe it will not make any difference, but I could be wrong, because I do not have this feature on my Connect Amps.
I don't know why low level isn't working; another question for REL, that.
R
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The only way I was able to get the hum to disappear while using the high level connection was:

Black ground to amp speaker negative
Rca cable from LFE on sub to the amp sub out

This exactly what REL says you should not do, as far as the first part is concerned, where class D amps are concerned, and Sonos Amp is from that class.
As to the RCA cable from LFE to the Amp, REL says that a RCA cable can be connected to any RCA jack on the Amp that is free, it need not be the Sub jack only. Grounding is done via the shielding on the RCA cable so plugging the RCA cable to the line in jack on the Amp should also work.
Above two points as per REL videos on how to connect their Sub to an amp. If this is not working for you, I suggest you ask REL for help and return the Sub if they cannot solve the problem, subject to the next paragraph:
Plugging anything, even a blank plug into the Sub out signals the Sonos Amp to strip out the lower frequencies from the Amp speaker terminals. You cannot bypass that - all that turning the Sub off in the Sonos options does is turn off the Sub; this is a new feature and I suspect it does not restore the full frequencies to the speaker terminals. But there is no harm in trying this and seeing if it changes the overall sound quality in a beneficial way. I believe it will not make any difference, but I could be wrong, because I do not have this feature on my Connect Amps.
I don't know why low level isn't working; another question for REL, that.

First, thank you for the detailed answers, I appreciate it.

I did also contact Rel and Sonos, Rel will get back to me after talking with an engineer. Seems like not many people have the new Sonos Amp and a Rel sub and have done this, or at least have not asked about it to them or online much.


To answer your question, using high level input I and lfe at the same time (They recommend having both, for movies and music i guess) and if I turn off “sub” in the Sonos app, I do get a difference in sound. Control seems to be reverted back to the sub, I can adjust the crossover and volume on the sub itself and it seems to be working. When I turn sub back on, it seems to add some sort of digital processing that changes the nature of the front speakers sounds.

The hum I am getting is audible if I turn the crossover up high, and when the sound is idle after playing. It auto standby after a few minutes and the humming seems to stop. The ground on or off, same result. RCA cable to lfe or Rca out, same result with high level. If I remove the Rca all together, I get extremely loud humming on the sub at all times.


I do have a Sonos Sub as well, but that’s paired with my 5.1 system and I do like the sound of this Rel for music, as that is what I use it exclusively for.
K
It might be useful to open a thread here on the following question:

What happens at the speaker terminals of the Sonos Amp if a blank jack is plugged into the Sub out jack? Are the speaker terminals then denied frequencies below the crossover setting of 80Hz even if there is nothing at the other end of the jack? And then does turning the Sub on/off in room settings for the Sonos amp in the Sonos app have any impact on what happens at the speaker terminals? Are low frequencies restored to the speaker terminals with the jack plugged in, but the Sub setting on off?

And/or pose this question in an email to Sonos Support.

All other questions are for REL to answer. But if you like the sound from the REL sub compared to the Sonos Sub, I would just keep listening to it and not overthink the matter.
K
This, from the horse's mouth:
https://relsupport.zendesk.com/hc/en-us/articles/115004649588-How-do-I-stop-my-subwoofer-from-humming-

Also see if the hum goes away by connecting both the amp and the REL to the same wall power socket, and stays away without the cable from the LFE to the Amp.
K
More intriguing results on googling from REL:

https://relsupport.zendesk.com/hc/en-us/articles/227195467-Tzero-Sonos-A-connectivity-Update

I know that this link does not refer to your specific model and this is referenced in the linked article, but I have not been able to find the link for another article mentioned that does.

But this one is interesting because it says that with Sonos, only a low level connection is recommended.

I also think that the article is not being completely honest is using as an excuse the Sonos lack of Hi Res capability to say that if you use low level connection, it is still ok because Sonos does not go the distance anyway as far as sound quality is concerned, so what is a little loss of Sub integration quality by using the low level connection? Hogwash, that excuse.

It seems to me that REL and Sonos are not a happy pairing. Perhaps due to the Sonos sleep mode feature as the article suggests, perhaps something else. After all this research I would not use REL with Sonos kit. In any case, I use the Sonos Sub for music and it does all I expect a Sub to, bonded to a play 1 pair.
R
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So i've not had luck with the high level connection, still getting a hum regardless of how I tried to do the ground.

I'm testing between using the Low level connection, and the LFE now to the Amp Sub out.

The only issue I have with the low level connection, is that the bass and gain seem to be considerably lower than the LFE, not sure yet if it's normal or just has to be turned up a bit.

I know theoretically LFE is for movies, but I'll see what type of bass response it gives me and if I can still adjust crossover. (The app allows me to, just need to confirm by listening that's working)

I wonder what are the downsides of using LFE for music, aside from the crossover being at 80hz? Does it strip out any other things?
K
No idea; I haven't used REL. The only additional information I have gleaned is that where the Sonos Amp is concerned, the frequency stripping at the speaker terminals happens only if something is plugged into the Sub out on the Amp AND that Sub is turned on in the Sonos app, under settings for the Amp in room settings. Even if that something is just a blank jack. So if you make sure that the Sub is turned off, you should not lose anything by wiring the Sub out to the LFE in as suggested by REL for hum elimination. If you do this, and let the black lead of REL float unconnected, according to REL there should be no hum for high level connections to class D amps like the Sonos Amp.
L
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Just my opinion, but I I find fault with Sonos for not allowing the sub output to be used without engaging the crossover. They could easily fix that with a firmware update, I would think. Maybe they will if enough people bug them. I sent an email asking for this a month or two ago.
K
Just curious; why do you need this? To present the main speakers with the full signal or to do the same to the Sub, using the Sub crossover for filtering?
And for getting either/both, won't high level connections work - the REL seems to have hum issues with these, but that seems to be a REL thing, not one related to high level connections as such.
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