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Connection connverters and performance?


Standard Member
Just moved house, just bought a fairly decent subwoofer phono – phono cable to link it to by amp, just unpacked the subwoofer and having not seen it for a couple of months discovered it takes a 3.5mm mini jack (the center and subwoofer channels are combined). Having gotten my brain engaged, I recall now that I used to have a 2xphono to 3.5mm and I used just one of phonos in the sub output of the amp with the other left dangling.
Anyway, having now bought this lovely new phono-phono subwoofer specific cable, I now need to buy a phono to 3.5mm converter, you know, those rubbishy little y-shaped plastic things for about £3 on ebay. It seems a bit of a waste to have an expensive cable but then to have such as weak link in the chain in such a converter.
Would performance be affected or is it that its actually a solid piece of metal in there that it doesn’t affect quality at all? Whats the general feeling on introducing such items into a reasonably decent system? I either have to buy a converter or a new sub?


Active Member

It is always helpful to post the make and model of the gear when asking a question, however I will have a go from what you have posted.......

Many subs have dual inputs to allow you to combine left and right channels, so that LF signals on either channel reproduced. I dont understand your comment about 'centre and subwoofer combined', did you mean left and right?

Quick rule of thumb (assuming an active sub):

1. If you are using an AV amp, in most cases it will have line level sub/LFE output. This will usually be mono, the AV amps processing will have mixed any LF information to this channel. Just run a mono screened lead from this output to the sub input.

2. If you are not using an AV amp, in most cases you will need to drive the sub with separate L&R line level signals and the sub will mix these together. Run two screened leads from the amp's line outputs to the sub inputs (your amp may not have these though).

3. In some cases the sub will allow you to connect speaker cables direct to the sub. In this case run a cable from each speaker (or from the speaker output on the amp) to the sub. The sub will mix L&R together.

Guessing your setup, you have case 1 above. The sub has a stereo jack input and the AV amp has a phono output. Assuming the AV amp has mixed any LF to mono, then a simple phono to jack converter you describe at the sub should be OK. Unless the adaptor is so shoddy that it doesn't make a connection or falls to bits, pretty much anything will do.

Just as an aside, there is no such thing as a subwoofer specific cable, except in the mind of a marketing exec. The only possible argument for subwoofer specific cable is that its frequency response is so poor that is it unsuitable for use as a general audio interconnect and can only be used for low frequency connections. I that is the case, I am not sure I would brag about it in my marketing material.

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