First message/question (audio interface + 4.1 speakers)

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Hi. This is my first message in this forum. I really appreciate your input regarding the following situation:

My music room is just my computer and turntable (I'm a vinyl collector). My setup during the last twenty years or so was a Sound Blaster Audigy 2 Platinum with third-party drivers (kX Project - The Creative ones are terrible) and a Cambridge SoundWorks FPS1800 4.1 speaker system (one subwoofer, two front satellites and two rear satellites). My room is pretty small, so this system fills it pretty well, and sounds great here.

But last week, my sound card died. So, I started to read reviews for audio interfaces and chose a Focusrite Scarlett 2i2. The thing, at first, was solving the problem of connecting the speakers, since the 4.1 has front and rear channels (both stereo), and the 2i2 has just two L-R output channels. But it wasn't difficult to solve: I connected the 2i2's left output channel to the front speakers inputs using a cable with a 1/4" plug on one end (2i2) and a 1/8" stereo plug on the other (active subwoofer - that's where the front and rear speakers input are). Likewise, I connected the 2i2's right output to the rear speakers input using another cable with the same plugs. After relocating the speakers, I got two fronts to the left and two rears to the right. I don't perceive any sound quality difference between front and rear speakers, so that way I could solve the stereo L-R positioning in the room.

And it sounds great, but here's the problem: now there's no (or barely any) sound from the subwoofer. It is working, since it has a master volume and on/off control that works, and also a volume control just for the subwoofer to adjust the bass amount to taste.

With my old setup, the subwoofer volume control didn't need a lot of push for the bass to fill the room. It was at around the 8:00 o'clock position. It's a really powerful subwoofer for my small room, but now I have to turn it all the way up to barely feel the bass. Of course, the bass can be heard, but it doesn't fill the room. It can be heard, but not felt. And the volume control makes a difference, but nothing compared with the powerful bass sound I could feel with my previous setup (with no need of pushing it all the way up). Of course, I could try using an equalizer, but that's not the point. The point is: this subwoofer has a very powerful sound without any kind of EQ, so it should work that way.

I guess this problem is related to the fact that the 2i2 only offers standard stereo speaker configuration (no 4.1), so I also guess that the only solution is ditching the 4.1 speakers (which, again, sound great in my room) and get a pair of studio monitors. But before doing that, I'd like to hear from the audio experts about a possible solution to this (if any) before saying bye to my current speakers (I don't want to do that, and will do it only if definitely there's no other solution).

Thank you for reading!
 
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As the fronts are both left, and the rears are both right, what is driving the sub? I woukd look first at where the sub is getting its signal from, as I'm guessing either there's an output level issue, or it's a phase issue, as the sub should be seeing a mix of left and right, but might be seeing L-R, which if fed from the left only, results in almost silence. Does the sub have a phase switch? If so, try it the other way round.

S
 
Sergeauckland said:
what is driving the sub?
Click to expand...

With the Sound Blaster sound card, the only thing that connected it to the speakers were two cables with stereo 1/8" plugs on both sides. One of them went from a line out jack to the "front" input jack on the back of the subwoofer, and the other one went from a second line out jack to the "rear" input jack on the back of the subwoofer. There wasn't a dedicated subwoofer signal connection. In that regard, there was no difference with the current setup. The difference now is that, before, the satellites were L-R / L-R, and now they are L-L / R-R.

The subwoofer doesn't have a phase switch.
 
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The 2i2's outputs are balanced. I assume your subwoofer's input is unbalanced, so how are you connecting the 2i2's output to ths sub? You say a cable with a 1/4 " on one end (Is this a TRS or just TS jack?) and a 1/8" stereo on the other. It sounds more and more like an issue of cabling.

S
 
I think that explains it. The sub takes in a stereo signal (A & B) and mixes it internally to mono (A+B). What you're doing it sending the sub a balanced signal (A+ & A -) which the sub mixes together and the result of mixing the same signal with its opposite polarity is 0.

What you need to do is to take only the tip signal from one output to the sub. The easiest way of doing this is to disconnect the wire going to the jack ring, that should work. Doesn't matter which end, but probably the 1/4" end will be easiest to get to.

S
 
Sergeauckland said:
I think that explains it. The sub takes in a stereo signal (A & B) and mixes it internally to mono (A+B). What you're doing it sending the sub a balanced signal (A+ & A -) which the sub mixes together and the result of mixing the same signal with its opposite polarity is 0.

What you need to do is to take only the tip signal from one output to the sub. The easiest way of doing this is to disconnect the wire going to the jack ring, that should work. Doesn't matter which end, but probably the 1/4" end will be easiest to get to.

S
Click to expand...

So, replacing the 1/4" TRS jacks with TS may be a solution?
 
Possibly, but a TS jack on the output of the 2i2 will short out the -ve output, which could cause distortion or even damage the output driver chip. You need to check on how the 2i2 manual recommends unbalancing the output. If they say to leave the -ve open circuit, then using a TS jack will be wrong.


Edit. According to the 2i2 gen 4 manual, it's OK to use a TS jack on the outputs at the back.
S
 
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Sergeauckland said:
Possibly, but a TS jack on the output of the 2i2 will short out the -ve output, which could cause distortion or even damage the output driver chip. You need to check on how the 2i2 manual recommends unbalancing the output. If they say to leave the -ve open circuit, then using a TS jack will be wrong.

S
Click to expand...

Although the manual says that TRS is recommended, it also says that both TS and TRS may be used.
 
Sergeauckland said:
What you need to do is to take only the tip signal from one output to the sub. The easiest way of doing this is to disconnect the wire going to the jack ring, that should work. Doesn't matter which end, but probably the 1/4" end will be easiest to get to.
Click to expand...

I've just did it with a little help from a friend, since I'm very bad at working with solder.

And guess what? It worked. IT WORKED! The subwoofer has returned. Thank you! Thank you very much! "Appreciate it" is not enough to express my feelings. This is one of the greatest things of the Internet. A thousand thanks! :)
 

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