How do you hook up a Sub?

No idea if I am on the right track here and likely to be a stupid question (no stupid questions, just stupid people, right?)…

Our old surround sound system for the TV died a while back but I thought I may be able to hook up the sub woofer speaker as part of my mixing set-up. And that’s where my actions have ended.

It has RCA inputs and out puts (stereo, marked R and L Low Input and R and L level output). Is this something I could use and if so, how the heck do I go about integrating it into my system (at the moment running two Profire 2626s with Reaper).

I am not a hardware tech kind of fella, so speak to me as though I was five please :slight_smile:

I’ve only ever investigated getting a studio subwoofer into my system. The way that would work is you would take the two TRRS / XLR plugs out of your monitors, and then connect them to the Sub’s inputs. You would then run the L & R output from the subwoofer into your monitors. So the subwoofer would handle the entire signal coming out of your interface, and then handle what is playing through the sub and the monitors. In fact, studio subs would let you control the crossover frequency. This means you would control what frequencies are going to play through the subwoofer, and which frequencies you would hear from the monitors. You would also get to control the overall level of the subwoofer as well as the phase.

For your situation, you have to see whether the subwoofer you’ve got is passive or active. If it doesn’t connect directly to an electrical outlet, it’s a passive subwoofer. In that case it’s going to be really hard to put it into your setup. You’ll need a separate amplifier for it. If it does connect to an electrical outlet, it’s an active subwoofer, with a built in amplifier. But generally home cinema systems use passive speakers for the L & R’s, so again, depending on your monitors you may get something or nothing by plugging your monitors into the subwoofer.

Now, the only way I could think of avoiding all of this hassle, would be to connect the subwoofer to the interface alongside your monitors. But in this case, you’d be routing your audio from your DAW into 2 monitors, and then the subwoofer. So essentially all frequencies would be sent to all three speakers. I think that defeats the point of having the subwoofer in the setup, but I could be wrong about this.

I think I’ll let somebody who actually has a subwoofer in their setup take over from here…

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Well almost right… In my case the direct outs (left and right) of my interface go straight to my subwoofer. The subwoofer has a knob to regulate the crossover frequency (i.e. the low frequencies that are handled by the sub and the higher ones that go to the monitors). But you will need a powered sub not a passive one (i.e one that needs to be connected to a 220 V socket - you do have 220 V in Australia don’t you? I can’t remember for sure). If you do use a passive one you not only need a separate amplifier but also a separate cross over filter. I was at one point thinking about this option, but you get better results and probably cheaper by looking for a second hand studio subwoofer. I did and never regretted it!

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I didn’t write my report correctly! As I was thinking about connecting a cinema sub to a studio situation, I also came to the conclusion that a half decent second hand studio sub would actually be the route to go

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I have a pair of these in my sub room. Though these arent my main monitors, I do use this quite often to reference mixes. It is pretty decent and straightforward to use. Comes with trs and unbalanced inputs, the filters and gain functions are real handy

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Hi Dan, I’m not running a sub but I looked at the manual for your interface and it has a pretty nifty software mixer you can run and the manual shows a set up for running a subwoofer as part of a surround sound setup. The mixer should allow you to configure the EQ for a sub but Reaper should be able to do that as well. Here’s the manual

And here’s the surround sound set up.

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This makes the most sense to me.
It is an active Sub. Unless someone is screaming “NO!! Don’t do that, it’ll blow up!” this may be the way to go.

Ok, so as above but instead of going from my monitors to the sub, I’d go from my interface to the sub first, then from the sub to the monitors? it is active and also has the frequency cross over too.

Thanks! I’m not too sure I’ll go down this path only in that I am likely to upgrade/replace or integrate these into a new system at some point this year. I also have the ins and outs configured a little differently to use some outboard gear too.
But I can;t thank you enough for going the extra mile to go as far as to look it up in the manual (I probably should have thought of that but didn’t think it would have that info in it!).


Your Profire 2626’s are really versatile and have lots of options; they seem like a great choice to do whatever you want. I only posted the surround sound setup as an example of what they are capable of, I’m sure they’ll work for however you want to set up your studio. I guess they’ve been around for a while and you could always go look for the latest and greatest

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It’s not so much them but my PC. It’s starting to show its age and is running Windows 7. There are a few layers to this. The Profires require certain chipsets that were hard to find ten years ago!
So I am likely to upgrade my PC and then upgrade interface but still use them as I have been told I can still chain them into the new interface - I’ve been informed this will work. We shall see.

Thanks again, Ingo!

So, here’s what I’m working with. Below are some images of my monitors and the sub.
Is it is simple as taking one of the outs (if so, which is preferable) of either the rca or the balanced trs from the monitors and simply plugging it into the rca low input of the sub and away we go?
Any suggestions based on those pics?

In my opinion that would make sense, BUT, before you try that, wait to get confirmation from a more informed IRD member. I’m not the most knowledgeable guy when it comes to this kind of thing.

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So, @Wicked, I completely disregarded your advice to wait and went ahead anyway.

I ran RCA cables from the monitors to the Lo Input of the sub. Nothing.
Tried various RCA cables to be sure but still nothing. I (as it will probably will be quite obvious to most) know little about this stuff, so it was likely an “of course that wouldn’t work” thing I have tried.

Any thoughts? Maybe TRS to RCA?

Hey Dan, you’re talking to a guy who is about as knowledgeable as the average teenager when it comes to this sort of thing. I kind of expected there to be an easy solution to hooking up those subs, but this sort of thing is not my forte.

You could try TRS to RCA, but before doing that it would be a good idea to learn more about it on google, YouTube or elsewhere. I can’t think of a reason that TRS to RCA would be risky…but, I’m not qualified to answer that question. Never trust me ! :grinning:haha. Maybe your local music store or a store that specializes in stereos and audio equipment would be able to help you out. I’d try giving them a phone call.

I hope you can get it sorted out and make use of the subs. Let us know how it goes, either way.

Hey Dan, I went through almost the same thing a couple of years ago. Here’s the thread.

I got a Focusrite 2i4 because it had extra outputs on the back. So I run the RCAs from my audio interface into the subwoofer which works really well!

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The manual for Dan’s interface shows that set-up but he says he doesn’t want to do it that way, I forget why.

You’ll just need to leave those speaker I/O’s alone on that sub.

The downside to using a sub like that is that you won’t have a crossover, so you may get some funkiness in the low end. Really all you can do is get a TS->RCA cable and run it from your interface into the sub. Your monitors don’t have a passthrough, and neither does the sub for line level.

A dedicated mixing sub will have XLR and/or TRS inputs as well as a crossover and passthrough so you can hook them up to your monitors from a single output without any issues.

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Thanks folks. Seems like I may have to hold off just for a touch then.

@ingolee - You are correct. The reason I didn’t want to go down the interface path is two fold. A) I have a few things set up through most of those outputs, which sounds like a lot but there is a weird routing thing I had to do to get headphones and monitors independent of each other and B) I will be likely upgrading my PC and interface later in the year so I may as well just wait. I don’t NEED a sub as such, I just had one lying around and thought I’d try it. I’ll just hook it up to my record player instead!

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