Setting up psw 450 sub, rt8001's and rt245i with Sony STR DB930 receiver

hugh

Hello from a delighted new owner of a set of Polk speakers in Ireland, possibly your first Irish member? This is the best set of speakers I have possesed and the overall sound and performance is really great with excellent definition and with the 450 sub, good clarity right down as low as I have ever heard (or rather felt!).

I have read all the threads about using the LFE input versus feeding the 800i's through the sub and am still a little confused, especially about using a y cable. At the moment I am using an ordinary single phono to phono cable from one of the two pre amp sub out connections to one of the two filtered LFE inputs. Is this the right kind of cable or is the cable mentioned in the threads something different and should I try and find a y cable? (Difficult in Ireland I would say). I have notice quite a bit of difference in the response of the sub depending on what the input source is, when the source is analogue and maybe not too strong (phono for instance) the performance does not seem to be too good.

I have also not been able to figure out the pros and cons of adjusting the db level for each of the speakers on the Sony DB930 receiver setup. If anyone has the patience to explain the best setup procedure to me, I would be really grateful.

By the way, my rear speakers are Acoustic Research bookshelf speakers, at the moment the 800i's are set to LARGE and the 245i centre speaker and the AR rear speakers set to SMALL.

I have found the information submitted by members to be really useful and informative, thanks to all those who take the time to share their knowledge and experience.

Hugh

CHRIS

Hugh-First off welcome to the forum . The ‘Y’ cable is needed for most dual voice coil subs t work their best. You can get a sub cable from www.monster.com.
As far as the db settings, sit where you will be sitting when watching movies. On your remote there will be a button labled test. When you push it you will get ‘white noise’ a type of test tone which will sound like a hiss or static out of your speakers. Set each speakers db so each speaker is of equal volume from where you are sitting when watching a movie. If you have an spl meter avalible to you set each speaker to 75db for best results, again pointing it at the speakers from where you sit to watch movies or the sweet spot. I had a Sony back when the model was a STR-DA925 it was the first to have DTS decoding I beleave, think, or IMO. If you have any more questions I will do my best I haven't had that receiver in almost 3 years so this is from memory and the best I could do at the moment.
Hope it helps.
BTW-IMO I would keep all but the 800s set to small. If you search around the Polk site or go o the site map. Loo for 'The Speaker Specialist' in either vol. 2 or 3 Paul did a section on bass manegment.

hugh

Hi Chris,
thanks for the welcome and for your advice. I will follow up your "lead" at monster.com and look at the speaker advice on the Polk site too. As having a sub is a new experience, I suppose I am not too sure what I should be aiming at. It would help if there some enthusiasts round here to visit but milking cows is more the order of the day than tweaking knobs on a sub woofer!
Cheers,
Hugh

jcaut

Hi Hugh, and welcome, as well!

I'm a little confused about something you said in your initial post. You said that you have a single RCA-type cable running from the "Sub Out" on the receiver to "one of the two filtered LFE inputs" on the sub. Are the "Sub Out's" on your reciever identical, or are they Left and Right? I figured that the PSW450 had only one "LFE" input (I don't have one, so I may be wrong), and that input should be UNfiltered. It also will have left and right line level inputs. If your receiver's "Sub Out" is a filtered, mono signal, then you really shouldn't use the L&R line inputs, since that would route the "already filtered" signal throuth the sub's variable low-pass filter.

I just wanted to try and clarify that.

If you're using the Left and Right Line Inputs on the Sub, then normally you would feed them the full range signal from the L&R "Preamp Out" on your receiver.

To sum up, I don't think you need to bother with finding a Y-adapter. Even if you were supplying a mono signal to the L&R line in, I believe Ken S. has said that for the PSW- subwoofers, it's fine to just use one of the jacks. Polk's Customer Service is top-notch, and could tell you for certain.

I hope that makes sense. I think you're right, on the Large/Small settings for your other speakers, as well.
Jason

hugh

Hi Jason,
Thanks for your contribution and for querying my information. The Sony DB930 has two pre amp sub outs, it says in the manual that they are for two subwoofers. It actually says "You can connect an active sub woofer to either of the two jacks. The remaining jack can be used to connect to a second active sub woofer". It doesn't say in the manual whether the signal is filtered or unfiltered. I was worried that I might be overloading the input by also connecting the 2nd sub out to the psw 450.

So at the moment I have just one lead from the one of the pre amp sub outs connected to one of the two L/R inputs! Any further suggestions appreciated.
Thanks in anticipation.

Hugh

jcaut

In that case, I'll stick with my previous post: Don't worry about a Y-adapter. Run a single RCA-type cable from one of your sub outputs to the "LFE IN" on the subwoofer, and you should be in business as far as connections go. Again, I'm not sure if that subwoofer has more than one LFE input. You should use the "
LFE IN" instead of the "L/R LINE IN" to avoid passing the signal through two filters.

My experience with Sony receivers is very limited, but I believe most of them let you choose a crossover frequency for the sub output. If you have that ability, I'd recommend setting it for 80Hz, or a little lower. I've got RT800i's, and they seem to have good output down to 50 Hz or so. My Denon receiver has a fixed 80Hz crossover on the sub out, and it seems to work really well. Your Sony may also allow you adjust the subwoofer output level differently for different sources, and/or surround modes. I can't help you there, so you might just have to check the manual.

Good luck, and enjoy your new Polks!
Jason