Don't know if these links will help or not but thought I would just throw them to you.

 http://www.smarthome.com/SLChowto04.html

http://reviews.cnet.com/4520-11254_7-6360441-3.html

I'm sure you tried amny things but just in case try a Google search and put in "hookup powered subwoffer to Sherwood model (put in your model number here)

I don't have much to help you with just thought I would give it a shot.

Well, no.  My receiver/amp COMES WITH a powered sub-woofer...so in my case yes, it works.

If you need to ask then I must assume [ass out of u and me, etc] that your powered subwoofer comes from something else...and your tuner does not normally use one....

...or something.

As that eff-wit from Queensland says... "please explain" ...

ok.. lets see if i got it right...... the only sub you have that has a amp in it is from a system where the sub acts as the receiver?

And you want to connect it to your sherwood 5.1 sourround reciever.....

Yes you can connect the sub to the "sub out" on your sheerwood to that sub... the sub probably allready have a crossover with a set hertz in it allready and if you want it higher you can probably set it on the sherwood.

A rca cable that you modify  with a 3.5mm at one end our if you can find a premade one.

Then there was the guy who built himself the 1000watt [rms] amp...to play his rekkids....and found he was getting way too much feedback via the stylus....so he left the speakers and amp in the lounge....rolled out the wires and stuck his 'table in the garridge.....

Went in and cranked it up to where Spinal Tap likes it....

Went out and setup the rekkid.

All was going well till he dropped the needle onto the disk.....

There was a bit of a 'pop'   [as you do]....

Followed by a quite noticeable crash....

Popping back inside he found a quite dusty Lounge...devoid of plasterboard....

Silly boy!!!   I would put the 'table inside a polystyrene box and put the lid on... then put the box in a closet lined with egg cartons to muffle external influences.

Some years back (late 70's) I had a 500w per channel Pye amp with a Pioneer EQ with boost... a pair home home-made speakers with 16" drivers; 10" woofers; x2 8" midranges and x2 tweeters per... at 3 parts full volume, fairdinkum. it could be heard at the pub in the next suburb.  Ah, those were the days.

Well things didn't work out quite as I had planned... the place where I had lay-byed the Sherwood receiver went a sold it on me, didn't they!  Pisseded me off severely cos I had gone out especially to go pick it up...

Oh well, all's well that ends well.  For their mistake, they replaced it with a more expensive Pioneer VSX 518K... about a 100 bucks more for the same price.  OK, it's not top of the line and it doesn't have HDMI, but it'll serve my purposes just fine... apart from my TV, the only HDMI ready component I have is a top-box, and that's not really needed as the TV has built-in HD. I'll still hook it up, though... to record stuff while I'm watching something else.  More to the point, the Pioneer has more inputs and now I can hook up my turntable, CD player and tape deck as well

The other thing that didn't work out... the Pioneer is a tad higher and won't fit into the compartment in my TV/entertainment centre.... fixed shelves.  Ain't gonna hack into a reasonably decent piece of furniture to make it fit, so tomorrow I'll pick up a RTA TV/component stand that'll go beside my current unit.

The fun part 'll be setting it up... you know, fiddling with wires and cables through those piss farty little holes most entertainment units come with.  The pain in the arse is that my hands won't fit though them... that I'll have to hook up one component at a time (7 in total) to save having a swag of cables hanging out the back and getting confused as to which belongs to what.

I just don't let PH bother me... she just doesn't warrant the energy to get that way.

Saw her recently at an Ipswich shopping centre... while many were clamouring to be noticed/get her attention, etc, we just walked casually by... went there to shop, not worship/pay homage.

Things like that used to bother me, like when I was younger, but being married to a woman of colour I ended up with a thicker skin... had to, otherwise I'd have been never-ending fighting from of all the snide comments floating around.  The World is full of unpleasantness and people with narrow-minded views on what is right or wrong, good or bad, but I soon came to the conclusion that if I allow their thinking to affect me I'll never be happy or at peace.

One day I was out with my daughter (who is dark like her mother) when this woman took a look at me, then at my daughter in the stroller and promtly spat in my face before shouting racial obscenities at me, etc. I could have responded and escalated what was already a bad situation, but it made better sense to wipe off her spittle, ignore her taunts and continue on my way... and I did. 

It was a case of 'sticks and stones, and my kids learned a valuable lesson... that if the ignorance and bigotry is to end it has to begin somewhere, and walking away is a good start. Hopefully this attitude will grow and influence younger generation... and the PH's of this World eventually become extinct.

I have no tolerance for it, either, I just don't go getting my knickers in a knot when the smarter thing to do is ignore the ignorance and walk away.  People like that derive more of a rise from getting a response to their slurs... and I'm not one to give it to them.  Walking away gets up their nose more... while they're continuing to make effwits of themselves I'm laughing inside and know that I'm the better person, on many levels.

Now if that woman had spat at my daughter the response would have been swift and decisive.  Not an advocate of violence or hitting women, but she likely woulda been sipping and spitting through a straw for a while had the target been my girl.

Bit of a different story here... it's an international/multi-cultural site and it must be nipped in the bud, in everyone's better interests.