REL high Level + Class D amp help pls !

[noiwk1991]

I think Chrispy's proposal, with which I agree is:
- 1 sub out connected to one sub
- 1 sub out connected to a Y splitter, connected to 2 subs. Especially if those subs are the Left-Right and located symmetrically.

LFE gets to be a confusing term as it has two meanings:
- in the AVR, LFE is a *channel* that contains movie effects like explosions, rumble etc.
- in the sub, the LFE input in your REL, and in other brands the LFE setting in the "crossover" knob, mean: let the AVR handle the low-pass filtering.

In your AVR, you should set the bass as: Main + LFE.
In that way, your subs connected via the sub outs will get the LFE channel PLUS the low frequencies of regular content in the L/C/R *channels*

i see, but i heard bad things about LFE + Mail due to double bass stuff

 

[Chrispy]

im confused? please explain again

Oops that is a confusing sentence, was watching an interesting video at the same time, sorry....should say: " rca pre-outs on your avr, and yes a splitter works fine" and use rca inputs on the subs.

You have a choice with the avr, you can set all speakers to "large" which simply means do not use bass management, i.e. bass redirection from the speakers' channels to the sub, or use "small" and use a crossover to split what essentially goes to the sub vs the speakers. LFE is independent of the bass management, but will only be sent to the sub via pre-outs (so if you use high level/speaker level connections only you would lose the the LFE channel when it exists, it of course does not exist in 2.0 content).

The LFE+Main setting will send the speakers full range content (i.e. they're set to "large"), and use the crossover setting just as a low pass filter, and send the lower frequencies to the sub as well. Called double bass in some avrs...

I prefer the avr's LFE setting for bass management rather than LFE+Main but I'd say experiment with both.

 

[noiwk1991]

Oops that is a confusing sentence, was watching an interesting video at the same time, sorry....should say: " rca pre-outs on your avr, and yes a splitter works fine" and use rca inputs on the subs.

You have a choice with the avr, you can set all speakers to "large" which simply means do not use bass management, i.e. bass redirection from the speakers' channels to the sub, or use "small" and use a crossover to split what essentially goes to the sub vs the speakers. LFE is independent of the bass management, but will only be sent to the sub via pre-outs (so if you use high level/speaker level connections only you would lose the the LFE channel when it exists, it of course does not exist in 2.0 content).

The LFE+Main setting will send the speakers full range content (i.e. they're set to "large"), and use the crossover setting just as a low pass filter, and send the lower frequencies to the sub as well. Called double bass in some avrs...

I prefer the avr's LFE setting for bass management rather than LFE+Main but I'd say experiment with both.

ok so RCA pre in avr you mean to the LFE or low level RCA in the subwoofer? and when you say RCA pre you mean like.. of the speakers? like Center pre = Y splitter connect amp 1 connect subwoofer in second? left front same just to the front left subwoofer? or you mean subout RCA ?

 

[Chrispy]

ok so RCA pre in avr you mean to the LFE or low level RCA in the subwoofer? and when you say RCA pre you mean like.. of the speakers? like Center pre = Y splitter connect amp 1 connect subwoofer in second? left front same just to the front left subwoofer? or you mean subout RCA ?

RCA is the cable/connector type, and is low level. This is a splitter you can connect to the pre-out of the avr, then connect the different rca cables to each sub from that (assuming you have male ends on your sub cables). It wouldn't matter which of the rca inputs you use on the sub, but possibly the one marked "LFE" would bypass the sub's low pass filter (mislabeled as a crossover), but if you set the "crossover" to max value it shouldn't matter either way.

No, do not use the center pre-out, it isn't setup for a sub at all. Use one sub pre-out on the avr with the splitter to cover your two subs for L/R, then use the sub in the center on the second sub pre-out.

 

[noiwk1991]

RCA is the cable/connector type, and is low level. This is a splitter you can connect to the pre-out of the avr, then connect the different rca cables to each sub from that (assuming you have male ends on your sub cables). It wouldn't matter which of the rca inputs you use on the sub, but possibly the one marked "LFE" would bypass the sub's low pass filter (mislabeled as a crossover), but if you set the "crossover" to max value it shouldn't matter either way.

No, do not use the center pre-out, it isn't setup for a sub at all. Use one sub pre-out on the avr with the splitter to cover your two subs for L/R, then use the sub in the center on the second sub pre-out.

ohh ok understood you now, thank you ! but then will having this 1 extra subwoofer really give any benefit? considering its not as good as the other two? i have 2 t/9x and 1 t/5 x would it even have any benefit to add the t/5 if cant use high level?

 

[Chrispy]

ohh ok understood you now, thank you ! but then will having this 1 extra subwoofer really give any benefit? considering its not as good as the other two? i have 2 t/9x and 1 t/5 x would it even have any benefit to add the t/5 if cant use high level?

I'm not much of a fan of subs that small to begin with, let alone Rel (the cost on those t9x is ridiculous, at least here in the US), but you would be somewhat limited by the lesser sub's capabilities, though, altho those two are probably similar enough to not matter a lot. Do you need a third sub in the center? Matching speaker positions may not be ideal placement for the subs at all. I'd probably place the smallest sub nearfield or behind my seat or similar, so it wouldn't have to work as hard to keep up with the larger ones. The f6 on the T9x is 27hz and the f6 on t5x is 32 hz, so not tons different and they probably have similar response otherwise.

 

[noiwk1991]

I'm not much of a fan of subs that small to begin with, let alone Rel (the cost on those t9x is ridiculous, at least here in the US), but you would be somewhat limited by the lesser sub's capabilities, though, altho those two are probably similar enough to not matter a lot. Do you need a third sub in the center? Matching speaker positions may not be ideal placement for the subs at all. I'd probably place the smallest sub nearfield or behind my seat or similar, so it wouldn't have to work as hard to keep up with the larger ones. The f6 on the T9x is 27hz and the f6 on t5x is 32 hz, so not tons different and they probably have similar response otherwise.

Umm.. too late is too late.. i bought the rels already and somewhat regret it now.. yes they are awfully expensive .. however ill say .. despite of the lame spech on paper.. when i connected them to high level they did sound great..

 

[Chrispy]

Umm.. too late is too late.. i bought the rels already and somewhat regret it now.. yes they are awfully expensive .. however ill say .. despite of the lame spech on paper.. when i connected them to high level they did sound great..

They're decent, but they don't dig particularly low, and they're generally overpriced. They're shiny and small, which some like (but there are other small/shiny sealed subs, too). Are these your first subs?

 

[noiwk1991]

They're decent, but they don't dig particularly low, and they're generally overpriced. They're shiny and small, which some like (but there are other small/shiny sealed subs, too). Are these your first subs?

no i had SVS before.. and the REL sound many times better than the SVS subs i had

Edit but thats when connected through high level. ill be honest i did not think about all this when i ordered the class D amp.. because on the video REL made it look very simple just leave the black wire floating and you are done and connected to high level on a class D .. and the apollon amps seems amazing .. buit now its getting so complicated.. that i start to think perhaps i should;ve just bought a class Ab locally here which would also be much cheaper and connect without issue. . but im sure these feelings will fade the moment ill find solution

 

[Chrispy]

SVS should be at least as good as Rel, but depends on models somewhat and how you conducted the comparison and how well you set the subs up. Many times better isn't really possible with subs, they're not that different among competent subs. High level connections are nice when you have no pre-outs nor bass management. You can still do your high level connections if you want but there's really no point to it with your avr. The goofy wiring is Rel only, no one else does that or markets quite like that, as its simply unnecessary....

 

[noiwk1991]

They're decent, but they don't dig particularly low, and they're generally overpriced. They're shiny and small, which some like (but there are other small/shiny sealed subs, too). Are these your first subs?

@jsilvela
both of you please can you watch this video by Rel and then answer question i make here?
after you watch the video.. here is my question <3 pls !

as you see in the video.. REL suggest that a subwoofer with 2 Low Level input should connect to the Pre RCA left and right of the main speakers (not the sub)
but if it only have 1 it should be connected to the sub output. right ?

my question is... : if i have 2 subs 1 for the right speaker 1 for the left speaker. . (ignoring the amp for now). i would then connect both to the RCA pre of the mains?
1 subwoofer connect to the front right RCA and second sub to the front left RCA ? or i would still need to connect it to the subout ?

now assuming the answer for this first question is yes to main front/right i assume this would also be case for the center with 1 sub since it has only 1 pre not left and right.

assuming this is all correct so far. lets now add the amp.. the external amp should also connect to the Pre RCA right ? if now i use Y splitter and connect both the amp and the subs to the RCA pre . would that still work ? ( assuming the answer for the first question was yes)?

if the answer to this second question is yes..
would i have to connect the Y splitter to the amp? or to the avr? which of these 2 send the signal to my subwoofer ? thank you !

 

[Chrispy]

If you want to follow Rel's thing, follow Rel's thing, I generally dislike most videos, too. Some comments, tho:

REL suggest that a subwoofer with 2 Low Level input should connect to the Pre RCA left and right of the main speakers (not the sub)
but if it only have 1 it should be connected to the sub output. right ?

If you're trying to align the sub to a specific speaker you'd just use a high level connection. You could add a low level connection for LFE content separately. Just noticed many subs have both a L/R input in case the sub needs to sum the signal to mono....but these only look to have mono rca inputs that I see from a picture of the amp of the t9x so not sure why you'd use right and left pre-outs.

Separately, generally you connect the plus and minus of the speaker output of the amp to a sub if using the high level inputs. It looks like the Rel uses a cable with three spade connectors (to connect to your amps' output terminals) to a speak-on connector (not rca type) to connect to the sub. I'm not sure how that is supposed to work with the three connectors on the amp side, I'll let jsilvela answer that, since he has a Rel.

If you do go with the high level inputs you would set no bass management in the avr, but use a sub pre-out for LFE to each of the subs rca inputs to get the LFE signal.

 

[jsilvela]

I agree with Chrispy's comment.

Let me try to clarify something in addition.
REL and John Hunter will generally steer you towards left sub, right sub, center sub. Meaning, feed different signals to each sub.

Whether this makes sense is a debated question. Many believe that, since humans are not capable to detect directionality below 80Hz (conservative estimate, more like 100Hz), then having *stereo* subs does not make sense.
Many Denons, like mine (AVR X1500H) will have two sub outs but send IDENTICAL output to both, i.e. mono sub.

Why the reason to have multi-sub if you send them the same signal? For acoustics reasons. Making the bass more even and powerful across your room.
That there is another rabbit hole to get into, and plenty of threads deal with that here at ASR.

Let me try to summarize a bit:

The recommended REL way:
If you have 3 subs for three channels, connect each sub to a single channel. I.e. both yellow and red wire to the red binding post of the single channel.
And if you're using a Class D amp, leave the black wire un-connected.
Having the black wire un-connected does not necessarily mean you'll have ground noise.

The way that Chrispy and I are recommending (we don't match 100%, but more or less):
Let the AVR do the bass management and integration. Bypass the high-level cables, and use the RCA out from your AVR to the subs (either to the LFE input or the low level).
Since your AVR has control for 2 subs, with a Y splitter, you could still connect 3 subs. But two of them would get the same input.
Now, the AVR is set up to handle the low frequency from the L/C/R channels, even if you have a single sub, so you're not "losing" any low frequency information.

 

[Willem]

My suggestion would be to go the Multi Sub Optimizer route. This means connecting them at low level to the same mono output from the AVR, and into a miniDSP 2x4HD. Connect all three subs to the 2x4HD outputs. The 2x4HD will allow you to equalize each of them individually for best in-room response over a wide area.

 

[noiwk1991]

I agree with Chrispy's comment.

Let me try to clarify something in addition.
REL and John Hunter will generally steer you towards left sub, right sub, center sub. Meaning, feed different signals to each sub.

Whether this makes sense is a debated question. Many believe that, since humans are not capable to detect directionality below 80Hz (conservative estimate, more like 100Hz), then having *stereo* subs does not make sense.
Many Denons, like mine (AVR X1500H) will have two sub outs but send IDENTICAL output to both, i.e. mono sub.

Why the reason to have multi-sub if you send them the same signal? For acoustics reasons. Making the bass more even and powerful across your room.
That there is another rabbit hole to get into, and plenty of threads deal with that here at ASR.

Let me try to summarize a bit:

The recommended REL way:
If you have 3 subs for three channels, connect each sub to a single channel. I.e. both yellow and red wire to the red binding post of the single channel.
And if you're using a Class D amp, leave the black wire un-connected.
Having the black wire un-connected does not necessarily mean you'll have ground noise.

The way that Chrispy and I are recommending (we don't match 100%, but more or less):
Let the AVR do the bass management and integration. Bypass the high-level cables, and use the RCA out from your AVR to the subs (either to the LFE input or the low level).
Since your AVR has control for 2 subs, with a Y splitter, you could still connect 3 subs. But two of them would get the same input.
Now, the AVR is set up to handle the low frequency from the L/C/R channels, even if you have a single sub, so you're not "losing" any low frequency information.

i see, sorry for delay. i was at the gym. but will connecting high level with class D amp dmg the amp in anyway?

 

[noiwk1991]

My suggestion would be to go the Multi Sub Optimizer route. This means connecting them at low level to the same mono output from the AVR, and into a miniDSP 2x4HD. Connect all three subs to the 2x4HD outputs. The 2x4HD will allow you to equalize each of them individually for best in-room response over a wide area.

mini dps is something i should check

 

[jsilvela]

i see, sorry for delay. i was at the gym. but will connecting high level with class D amp dmg the amp in anyway?

No, just remember to leave the black wire unconnected, as per REL manual for class D generally.
Remember, if you do this, to set the channel to Large on the AVR.

 

[noiwk1991]

No, just remember to leave the black wire unconnected, as per REL manual for class D generally.
Remember, if you do this, to set the channel to Large on the AVR.

thank you.. so stressful hope it works fine

 

[jsilvela]

thank you.. so stressful hope it works fine

One step at a time; you'll be fine

 

[Chrispy]

Just try to keep an open mind and maybe try each configuration, in the end it's not "reference" but rather "preference".....