Connecting high level on REL subwoofer by biwiring

Jackm219

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I'm currently running two rel q100e subs in a 5.2 setup. Each sub is connected to the speaker terminal on the amp of each front speaker - essentially a sub for each front. (First picture)

I'm now looking to biwire my front speakers and am confused how to plug in the high level speakon connection for the subs. The neutrik speakon cable from my sub is a biwire cable so do I treat it like a speaker and do normal biwiring or do I merge the +be and -be speakon cable and plug them into the lf+ and lf- only. Or do something else? Hope this is clear from my pictures.

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Any help much appreciated.
 

Jackm219

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Pictures aren't working. They basically show scenarios of where to plug the hf+, hf-, lf+, lf- from the speakon cable out of the sub.
 

macdiddy

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on how to post photo's on this forum.

https://www.whathifi.com/forum/topic-and-miscellaneous/posting-photos-new-forum

as to how to connect your subs, surely the easiest way is to run two cables from the dual subwoofer outputs on the back of your amp to either of the inputs on the back of your subs.

either use two phono to neutrik cables or two phono to phono.

*music2*
 

Benedict_Arnold

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^ For powered subs, yes.

For UN powered subs, no.

Connecting the low voltage low current unamplified sub outs from an AVR to the speaker terminals of an UN powered sub most likely won't produce any sound at all. It may also overload the AVR and make it smoke.

Connecting speaker level outs from an AVR to the RCA inputs of a powered sub will certainly blow the sub's amplifier and the AVR. As my stepson found out the hard way.

If the OP is intent on using a separate power amp plus an UN powered sub, then he should run an RCA interconnect from the sub out on his AVR to the UN amplified input on his power amp, then speaker cables (hefty ones) from the speaker terminals on the power amp to the SPEAKER level inputs on his sub.
 

Jackm219

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Just to clarify what type of sub I have. It is an rel which means it has an life output (rca to sub out of amp) and a high level neutrik speakon output (very uncommon in normal home cinema subs). The rca is connected as normal. But the end of the neutrik speakon I plug into the amp is bare wire.

This bare wire is intended to be plugged into the speaker terminals at the amplifier.

My my question relates to how to plug the high level sub input into biwire speaker terminals at the amp end.
 

macdiddy

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90_3.jpg


if not then could you try to re-posting your pictures as to be honest I am confused at your current setup and can't really help you any further until you do.

sorry. *unknw*
 

macdiddy

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maybe you should do some research before posting a reply, if you had then you would know that the Rel subs the op uses are of the powered variety.

also I don't know where you got the idea that the op was thinking of using a separate power amp to use with his subs as there is no mention of this in his original first post.

to be honest, until the op has another go at re-posting his pics then I am also unsure what advice to give, maybe if it aint broke then don't try something that may not make any difference.

*unknw*
 

Jackm219

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Yes that is what the back of my sub looks like. All I'm saying is I know how to plug the 2 subs into the speaker terminals at the amp.

But I now want to biwire my front speakers. So how do I plug the subs in then. I am referring to plugging in the neutrik speakon cable at the amp end.
 

andyjm

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Jackm219 said:
Yes that is what the back of my sub looks like. All I'm saying is I know how to plug the 2 subs into the speaker terminals at the amp.

But I now want to biwire my front speakers. So how do I plug the subs in then. I am referring to plugging in the neutrik speakon cable at the amp end.

Jack,

Firstly, bi wiring is a complete waste of time, but if you are determined to do it anyway, you shouldn't need to change the way you have connected the subs.

If you could give us more details of the exact wiring you have in place (particulary how you have currently connected the two red cables from the sub's speakon connector), we may be able to be more help.
 

Benedict_Arnold

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Jackm219 said:
Yes that is what the back of my sub looks like. All I'm saying is I know how to plug the 2 subs into the speaker terminals at the amp.

But I now want to biwire my front speakers. So how do I plug the subs in then. I am referring to plugging in the neutrik speakon cable at the amp end. 
If your subs are of the POWERED variety then DO NOT connect them to the speaker output terminals of the power amp. You will certainly fry the amplifier inside the sub and possibly your AVR as well. Use the RCA subwoofer outputs on the AVR and run an RCA subwoofer cable to each sub. If you have two subs and only one output on your AVR you can use a short 1 male / 2 female RCA splitter cable or a 1 male / 2 female adaptor plug.

As for the rest we need a sketch...

Bi-wiring by and large is a waste of time. Instead use single runs of better speaker cable. If you speakers have two pairs of inputs for bi-wiring, one simple improvement CAN be to replace the brass links on the terminals with short lengths of the same speaker wire as used on your main runs.

Bi-AMPING is an argument that goes on here forever, on the other hand. If you want to use two separate monoblocks, one for each speaker, then just run an RCA cable form the preamp outputs of your AVR (NOT the speaker terminals) to the RCA inputs on each monoblock, then speaker cables from each monoblock to the speaker it drives. If your monoblocks can be "daisy chained" then run a single RCA cable, say, from the front left pre-amp output on the AVR to the RCA inputs on the first monoblock, then a second RCA cable from the "chain out" on the first monoblock to the input on the second.

If you want to bi-AMP each speaker, using a total of FOUR monoblocks, repeat as above, but use an RCA 1 male / 2 female splitter and run a separate RCA cable to each monoblock. Then run one speaker cable from any given single monoblock's speaker output terminals to one pair of terminals on each speaker. Be sure to get the lefts and rights properly paired and be sure to take the brass jumpers off the speakers' input terminals. Tip there: to avoid loosing the brass jumpers just loosen one set of speakers terminal screws, swing the jumpers out of the way so that they are no longer connected, then re-tighten.
 

andyjm

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Benedict_Arnold said:
If your subs are of the POWERED variety then DO NOT connect them to the speaker output terminals of the power amp. You will certainly fry the amplifier inside the sub and possibly your AVR as well. Use the RCA subwoofer outputs on the AVR and run an RCA subwoofer cable to each sub.

Benedict,

Not so. A number of powered subs, particularly at the lower end of the market have both high level inputs (you connect the sub's input to the speaker outputs of your main amp) and low level (you connect the sub's input to the LFE output of an AVR or processor) .

The REL sub owned by the OP has high level inputs connected via a speakon connector, and low level inputs connected by RCAs.

The electronics in the sub attenuates the high level input before feeding it to it's internal amp.
 

Benedict_Arnold

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Many many subs have both RCA and speaker level inputs, agreed. The point is NOT TO connect speaker level outputs from the AVR to line level inputs on the sub. Only connect line level to line level, speaker level to speaker level.

Some Simple sums:

Error #1 - Connect Line Level (RCA) Output from the AVR to the Speaker Level Input on the Sub

​The line level outputs of an amplifier are typically around 0.3 volts RMS. The impedances of the downstream devices are usually high (typically 10,000 Ohms or 10kOhm, so that very little current.is drawn through the line (RCA) wire.

Typically, the current driwn, I, is given by the voltange applied (V) divided by the impedance (R). That's Ohms Law as you may remember from school physics.

S the current drawn through a properly connected line level cable is 0.3 volts divided by 10,000 Ohms = 30 MICROamps.

Now, if you put 0.3 volts across a typical 8 ohm speaker, it'll try to draw 0.3 volts divided by 8 Ohms = 37.5 MILLIamps, or about 1,250 times more current.

This will almost certainly blow the line out circuit on the AVR, as my teenage stepson found out the hard way.

Error #2 - Connecting Speaker Level Outputs to Line Level Inputs

Now. let's assume you're trying to pump, say 32 watts (not a lot) into an 8 Ohm speaker. 32 watts keeps the sums easy, which is why I've chosen that number. The power in Watts is given by the current in amps squared mutiplied by the impedeance. So the current is equal to the square root of (32 amps divided by 8 Ohms) = the square root of 4 = 2 amps. See I told you 32 watts kept the sums easy!

So. 2 Amps, 8 Ohms, That, using Ohms Law again, means a voltage of 16 volts. So what your AVR amplifier does is to raise the voltage to 16 volts and the current that flows is a consequence of the voltage, not the other way around.

So you try putting 16 volts across a 10,000 Ohm line level input. That's 16 volts comapred to 0.3 volts, or about 43 times as high as the line level voltage it was intended to handle. The resulting current will be 16 volts divided by 10,000 Ohms = 1.6 milliamps, or about 500 times what it was intended to take. That'll sure as Sherlock fry the low voltage side of the sub's internal amplifer, and it it doesn't, it'll be tring to push so much power through the sub's speaker coil it'll blow that instead.

If you don't believe me, try it and get back to me. After the Fire Brigade leave.
 

andyjm

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Benedict_Arnold said:
Many many subs have both RCA and speaker level inputs, agreed. The point is NOT TO connect speaker level outputs from the AVR to line level inputs on the sub. Only connect line level to line level, speaker level to speaker level.

Indeed.

Who suggested otherwise?
 

Benedict_Arnold

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Just a warning to the OP.

Some people make the mistake of assuming that because a sub has line level and speaker level inputs they are interchangeable. They are not, of course.
 

Jackm219

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Thanks for all your reponses. I think some of you don't fully understand my setup and I aim to clarify that now.

Firstly: REL subwoofers are different to the majority of subwoofers. You do have a high level output (from the neutrik speakon input) and this is designed to be plugged into your speaker outputs on your AVR.

Typically, you plug one end of your neutrik speakon cable into the sub (via neutrik speakon plug) and the the other end (bare wires) into your amp -

for a 2.2 setup you twist the yellow and red cables together and plug into positive right speaker terminal on amp and plug the black cable into the negative right speaker terminal. This is the right sub now set up. You repeat for the left sub but plug into the respective left terminals.

That is the setup I am I am currently using.

but what if I no longer have one positive and one negative speaker input for left and right I.e. Biwired outputs. Where do I now plug the REL wires?

Without meaning to to be patronising, this is a very specific question! I am aware how to connect a regular subwoofer.

It it does seem that a lot of people have not heard of these subs. I highly recommend looking into them and how the combination of high level and LFE is truly spectacular. It also means you can encorporate subwoofer(s) into a traditional stereo music setup.
 

Benedict_Arnold

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I think you had best ask the manufacturer then.

Apologies if we sounded patronising but you would (or perhaps would not) be amazed at how many newcomers try silly things and end up blowing up their gear.

FWIW bi-wiring WON'T improve sound quality or decibels. Bi-amping can repeat can improve sound quality, but not necessarily, and you will need a ten-fold increase in power (e.g. from 50 watts to 500 watts) to increase the sound pressure by a factor of two (10 decibels).

If I were you I would simply run simple reasonable quality subwoofer cables from the subwoofer output(s) of your receiver to the RCA inputs of you subs and simple two-core reasonable quality speaker cables from the speaker outputs of your receiver to the speaker terminals on your speakers.
 

andyjm

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Jackm219 said:
Thanks for all your reponses. I think some of you don't fully understand my setup and I aim to clarify that now.

Firstly: REL subwoofers are different to the majority of subwoofers. You do have a high level output (from the neutrik speakon input) and this is designed to be plugged into your speaker outputs on your AVR.

Typically, you plug one end of your neutrik speakon cable into the sub (via neutrik speakon plug) and the the other end (bare wires) into your amp -

for a 2.2 setup you twist the yellow and red cables together and plug into positive right speaker terminal on amp and plug the black cable into the negative right speaker terminal. This is the right sub now set up. You repeat for the left sub but plug into the respective left terminals.

That is the setup I am I am currently using.

but what if I no longer have one positive and one negative speaker input for left and right I.e. Biwired outputs. Where do I now plug the REL wires?

Without meaning to to be patronising, this is a very specific question! I am aware how to connect a regular subwoofer.

It it does seem that a lot of people have not heard of these subs. I highly recommend looking into them and how the combination of high level and LFE is truly spectacular. It also means you can encorporate subwoofer(s) into a traditional stereo music setup.

Jack, just to reiterate my previous comments, biwiring is a waste of time. However if you really want to do it, you need to give us more information about the amplifier and speakers you are using and how you intend to do the biwiring, as biwiring can mean different things to different people. I am familiar with the model of sub you have, but please explain clearly what connections on your amplifier will go to which connections on your speakers in your planned biwire setup - we can then advise you on how to attach the sub(s).
 

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