Wiim Ultra with REL T/x series subwoofers

[Promso]

Hi Guys!
I bought Wiim Ultra and pair of active speakers with integrated amps.
Think to order now REL T7X subwoofer, but I found in manual that they highly recommend to connect the sub as an inactive speaker for best quality. Screenshot from manual attached.

Anyone tried to connect such sub to Wiim Ultra? Which connection method you use? How is the quality?

I’m thinking that maybe it will not perform as well as it should if just connecting through sub out on Wiim and then maybe not even worth to overpay for this nicely sounding sub and just order something a bit cheaper.

 

[m_sherzod]

I connected my ULTRA by splitter cable to both HT1205 Mk2 L/R IN. I did it instead of just using one cable to LFE IN on the Sub.

It slams harder, more punchy and requires less volume set on Sub. Now it seems to me that it's better

Why is this happening? Is it because there is simply 2x signal is going to it? Could this have any additional benefits from just simple one cable connection? Any risks? Additional noise or something?

Thanks for reminding me. Do I connect the sub and Wiim Ultra using the following cable?))

 

[Promso]

Thanks for reminding me. Do I connect the sub and Wiim Ultra using the following cable?))

View attachment 16036View attachment 16037View attachment 16038

At least for me today in the shop they recommend to connect without split cable, just simple single one and connect to any port of JL d108. I took it for testing at home, will try to connect it tomorrow and will let you know.

 

[harkpabst]

At least for me today in the shop they recommend to connect without split cable, just simple single one and connect to any port of JL d108.

And they are right. There should be no difference (and thus no advantage) when using a splitter cable.

The separate left/right inputs are for cases where there is no monophonic (and probably low pass filtered) subwoofer output. If the "preamp" (or the device controlling the volume) just has stereo outputs the sub must be able to sum them to a single mono signal.

 

[m_sherzod]

And they are right. There should be no difference (and thus no advantage) when using a splitter cable.

The separate left/right inputs are for cases where there is no monophonic (and probably low pass filtered) subwoofer output. If the "preamp" (or the device controlling the volume) just has stereo outputs the sub must be able to sum them to a single mono signal.

Already ordered the split cable

 

[m_sherzod]

At least for me today in the shop they recommend to connect without split cable, just simple single one and connect to any port of JL d108. I took it for testing at home, will try to connect it tomorrow and will let you know.

Wow, cool. We will have the same subs) let me know how you like it? Mine should arrive in a week or so..

 

[sNc]

There should be no difference

But there is, at least with HT 1205 version

 

[slartibartfast]

And they are right. There should be no difference (and thus no advantage) when using a splitter cable.

The separate left/right inputs are for cases where there is no monophonic (and probably low pass filtered) subwoofer output. If the "preamp" (or the device controlling the volume) just has stereo outputs the sub must be able to sum them to a single mono signal.

Is it possible that feeding the same mono signal to both left/right inputs boosts the signal similar to correlated signals to a subwoofer?

 

[harkpabst]

The output level of the sub could be increased by 3 dB, indeed, depending on how the summation of the left and right signal is done. In this case I would rather decrease the WiiM subwoofer output level than turning the volume knob on the sub counter-clockwise. But there's no technical reason for improved performance. Not even REL recommend the use of a splitter cable.

Using the splitter cable the WiiM subwoofer output has to work into half the impedance, resulting in twice the current. Unfortunately REL don't bother to provide meaningful technical data like input impedance, but usually this shouldn't be an issue. But neither is it advantageous.

 

[rccarguy]

Using the splitter may also correct issue of low input level and the sub shutting down too often.

 

[harkpabst]

Using the splitter may also correct issue of low input level and the sub shutting down too often.

It may or it may just not. Auto-on and auto-off functions usually sense the input voltage, not the input power or current. The voltage stays the same (or worst case decreases slightly in case the input impedance really gets too low), current and power increase.

 

[m_sherzod]

Such an interesting hobby, there is not even a general consensus on how to connect a sub..))

 

[wkamil]

The output level of the sub could be increased by 3 dB, indeed, depending on how the summation of the left and right signal is done. In this case I would rather decrease the WiiM subwoofer output level than turning the volume knob on the sub counter-clockwise. But there's no technical reason for improved performance. Not even REL recommend the use of a splitter cable.

Using the splitter cable the WiiM subwoofer output has to work into half the impedance, resulting in twice the current. Unfortunately REL don't bother to provide meaningful technical data like input impedance, but usually this shouldn't be an issue. But neither is it advantageous.

I can confirm that the SVS SB-1000 plays louder when connected to the wiim ultra with a splitter than when connected with a single cable.

 

[Promso]

I can confirm that the SVS SB-1000 plays louder when connected to the wiim ultra with a splitter than when connected with a single cable.

Is playing louder max volume still good quality sound? Or it is just riseing volume level and max volume for good quality will be still the same? If second option, then no sense to use splitter, turn up volume knob on sub if you need that.

 

[wkamil]

At the same volume level set on the wiim ultra and on the subwoofer, connecting the cable from a single cable to a splitter causes the subwoofer to play a little louder in my set. I'm just stating a fact. Setting the subwoofer volume knob to maximum is asking for trouble.

 

[Promso]

At the same volume level set on the wiim ultra and on the subwoofer, connecting the cable from a single cable to a splitter causes the subwoofer to play a little louder in my set. I'm just stating a fact. Setting the subwoofer volume knob to maximum is asking for trouble.

Im not telling to turn volume max, I telling to compare if it is sounding better on maximum still ok volume in both options.

 

[Promso]

Wow, cool. We will have the same subs) let me know how you like it? Mine should arrive in a week or so..

To be honest I think it is too small sub for my room (42m2) I dint feel big difference without it. Let me know about yours when it arrives.

 

[harkpabst]

I can confirm that the SVS SB-1000 plays louder when connected to the wiim ultra with a splitter than when connected with a single cable.

That complies with theory, if the summing to mono results in summed voltages. The difference should be around 3 dB SPL, which is usually perceived as "a little louder".

 

[slartibartfast]

That complies with theory, if the summing to mono results in summed voltages. The difference should be around 3 dB SPL, which is usually perceived as "a little louder".

Wouldn't it be 6dB due to correlated signals?

 

[harkpabst]

Wouldn't it be 6dB due to correlated signals?

This is an electrical summation, so I think twice the voltage (if the signals are 100% correlated, same frequency distribution and phase) should be the maximum value possible. Double the voltage means twice the output power to the singlensound source, that the sub represents.

 

[slartibartfast]

This is an electrical summation, so I think twice the voltage (if the signals are 100% correlated, same frequency distribution and phase) should be the maximum value possible. Double the voltage means twice the output power to the singlensound source, that the sub represents.

Isn't 20 log(V1/V2) still 6dB?