Questions regarding passive vs active audio switch box for subwoofers

[dlovesmusic]

Hi everyone, just bought a Benchmark LA4 preamp, which comes with a mono XLR single output for powered sub.
However, I have 2 subwoofers, only taking RCA input and i will need about 30' cable run from the preamp to the subwoofers.

I looked at different options and found the following:

1) Nobsound Little Bear MC3 3-IN-3-OUT XLR Balanced/RCA Stereo Converter Audio Selector Splitter Box passive preamp XLR to RCA Audio Switch (XLR & RCA)

https://www.amazon.ca/Nobsound-Balanced-Converter-Audio-Selector/dp/B07D7P7366/ref=asc_df_B07D7P7366?tag=bingshopdesk-20&linkCode=df0&hvadid=80676757818148&hvnetw=o&hvqmt=e&hvbmt=be&hvdev=c&hvlocint=&hvlocphy=&hvtargid=pla-4584276311186662&psc=1

So I can put the Little Bear switch box closer to the two subwoofers, run a single XLR cable from the Preamp mono XLR -> XLR splitter -> Little Bear XLR input -> Little Bear RCA output L and R to the two subwoofers.

My question is - does it mean that from the Preamp all the way up to the Little Bear switch box, I still maintain a balanced connection up until the Little Bear reroute/convert to RCA output? If that's the case, it seems to be a better option as opposed to using a XLR splitter and running a pair of 30' XLR to unbalanced RCA cables from preamp up to the two subwoofers?

2) ArtPro - Cleanbox Pro - Dual Channel Level Converter

CLEANBox Pro – Dual Channel Level Converter – ART Pro Audio

artproaudio.com

This is active and converts XLR input to RCA output. So I can put this box closer to the two subwoofers, run a single XLR cable from the Preamp mono XLR -> XLR splitter -> Artpro XLR input -> Artpro RCA output L and R to the two subwoofers.

Is that a better option than a passive option?

Any advice will be greatly appreciated.

Cheers

 

[kemmler3D]

Hi everyone, just bought a Benchmark LA4 preamp, which comes with a mono XLR single output for powered sub.
However, I have 2 subwoofers, only taking RCA input and i will need about 30' cable run from the preamp to the subwoofers.

I looked at different options and found the following:

1) Nobsound Little Bear MC3 3-IN-3-OUT XLR Balanced/RCA Stereo Converter Audio Selector Splitter Box passive preamp XLR to RCA Audio Switch (XLR & RCA)

https://www.amazon.ca/Nobsound-Balanced-Converter-Audio-Selector/dp/B07D7P7366/ref=asc_df_B07D7P7366?tag=bingshopdesk-20&linkCode=df0&hvadid=80676757818148&hvnetw=o&hvqmt=e&hvbmt=be&hvdev=c&hvlocint=&hvlocphy=&hvtargid=pla-4584276311186662&psc=1

So I can put the Little Bear switch box closer to the two subwoofers, run a single XLR cable from the Preamp mono XLR -> XLR splitter -> Little Bear XLR input -> Little Bear RCA output L and R to the two subwoofers.

My question is - does it mean that from the Preamp all the way up to the Little Bear switch box, I still maintain a balanced connection up until the Little Bear reroute/convert to RCA output? If that's the case, it seems to be a better option as opposed to using a XLR splitter and running a pair of 30' XLR to unbalanced RCA cables from preamp up to the two subwoofers?

2) ArtPro - Cleanbox Pro - Dual Channel Level Converter

CLEANBox Pro – Dual Channel Level Converter – ART Pro Audio

artproaudio.com

This is active and converts XLR input to RCA output. So I can put this box closer to the two subwoofers, run a single XLR cable from the Preamp mono XLR -> XLR splitter -> Artpro XLR input -> Artpro RCA output L and R to the two subwoofers.

Is that a better option than a passive option?

Any advice will be greatly appreciated.

Cheers

I think technically the passive solution *should* give the best quality, but even at a 30 foot run you shouldn't have big problems with noise on an unbalanced connection.

The active box will have its own noise floor which could be higher than the Benchmark (likely is) so I'd try a passive solution (even just a Y-cable, maybe?) first.

 

[dlovesmusic]

I think technically the passive solution *should* give the best quality, but even at a 30 foot run you shouldn't have big problems with noise on an unbalanced connection.

The active box will have its own noise floor which could be higher than the Benchmark (likely is) so I'd try a passive solution (even just a Y-cable, maybe?) first.

Thanks before the benchmark preamp, I used a Freya + and Sim audio preamp (xlr to power amp and 30 foot run rca to the subwoofers), it seem to work fine.

With the benchmark preamp, the xlr output voltage is so much higher than the rca output voltage so I can’t just go directly from rca output to the subs. Hence I am looking at using the xlr mono output of the benchmark, split it up and feed rca to the subs

 

[antcollinet]

My question is - does it mean that from the Preamp all the way up to the Little Bear switch box, I still maintain a balanced connection up until the Little Bear reroute/convert to RCA output? If that's the case, it seems to be a better option as opposed to using a XLR splitter and running a pair of 30' XLR to unbalanced RCA cables from preamp up to the two subwoofers?

If how it works : electrically generates unbalanced outputs from balanced inputs, then yes this is a much better solution than splitters/XLR to RCA cables.

However it would appear to be passive - in which case, all it will do to convert to RCA will be to split off the hot pin from the XLR to the Pin of the RCA - In which case no balancing is going on, and you might as well do it with passive XLR to RCA cables.

Then the active ART pro device should do a better job in terms of creating a balanced connection for the greater length of that 30ft.

 

[dlovesmusic]

If how it works : electrically generates unbalanced outputs from balanced inputs, then yes this is a much better solution than splitters/XLR to RCA cables.

However it would appear to be passive - in which case, all it will do to convert to RCA will be to split off the hot pin from the XLR to the Pin of the RCA - In which case no balancing is going on, and you might as well do it with passive XLR to RCA cables.

Then the active ART pro device should do a better job in terms of creating a balanced connection for the greater length of that 30ft.

Just to clarify, with the passive box, isn’t the initial connection from benchmark preamp xlr output to the passive box xlr input remain a balanced connection?

 

[antcollinet]

Just to clarify, with the passive box, isn’t the initial connection from benchmark preamp xlr output to the passive box xlr input remain a balanced connection?

Not if it is just connecting XLR hot to pin of the RCA.

A balanced connection needs both hot and cold to go into a differential amp to allow common mode noise to be cancelled. You can't have a passive balanced input. The only exception would be if it was passively converting using a transformer in the box. I suspect it is not.


EDIT - here is the review - no transformer.

Little Bear MC3 XLR & RCA Switch Review

This is a review and detailed measurements of the One Little Bear (Nobsound/Duok) Little Bear MC3 XLR and RCA switcher. It is on kind loan from a member and costs US $69.99. I like the large knobs although I wished they had aligned them better. As you see, you can switch between one RCA and two...

www.audiosciencereview.com

 

[dlovesmusic]

Not if it is just connecting XLR hot to pin of the RCA.

A balanced connection needs both hot and cold to go into a differential amp to allow common mode noise to be cancelled. You can't have a passive balanced input.

Thanks so I am probably better off with the Artpro

 

[antcollinet]

Thanks so I am probably better off with the Artpro

That is what I would choose.

 

[dlovesmusic]

Update: so I picked up the Art Pro two channel level converter today. I am still waiting for the long run xlr cable and xlr splitter to come, but it should be pretty straight forward to use.

I was reading the manual and was a bit confused about what this feature does or its use case - “inline balanced or unbalanced level/gain control”??

It requires looping either the balanced output to balanced input or unbalanced output to unbalanced input to achieve an inline level/gain control…

Maybe for people to use this as an active attentuator? Say you have too much gain in your preamp and you use this to adjust the level?