PSW 650 hookup suggestion

Kjeng

hi Polkmanias,

The last receiver I bought was a Sony with Pro Ligic 10 years ago. Recently I have decided to catch up with the new Home Theater and Stereo scene. This is my basic setup:


2 RTi 70 for Front
CSi 40 for Center
FXi 50 for Rear Surround

Harman Kardon AVR 8000 Receiver

The speakers are hooked up using Acoustic Research 12 gauge wires.

I have also ordered PSW 650, but it was backordered since late Feburary. The store just called me today and told me the sub came in today. I am quite excited expecting to pickup the sub tomorrow.

Right now the system is setup without the subwoofer. The system sounds really good when I listen to Classical music. However, the system sounds really bad when I put in Techno or Drum N' Bass. The bass response and frequency are just not there. The speakers are setup so that Front, Center, Surround are all set at "Large" in bass management. Subwoofer is set to "None."

After reading "Case against subwoofer output" on Polk University. I am really confused. I was wondering if anyone can give me some suggestion.

On my Harman Kardon AVR8000, there's a "LFE/Subwoofer Preout." I suppose that's where the Subwoofer jack would go. However, I do not know whether the LFE is filtered or not. In Bass Management of AVR8000, I can either choose SUB/LFE or SUB LFE+L/R. Which mode should I choose.

I want to be able to enjoy the LFE of movies and also use my subwoofer when listening to music.

On the manual for PSW650, there are 4 options of connecting the subwoofer to the system. 2 of the methods don't apply to my situation because i don't have a pre-amp/processor and i am not using small speakers. That left me with either connecting speaker wires to input on sub and output to front speakers (Option 1) The 2nd option is just to connect front speaker to the receiver and use LFE preout to LFE in on the subwoofer (Option 3)

Suppose I choose option 3 above(which is the easiest), and then in Bass Management, selecting Front as "Large", Center "Small", Surround "Small", LFE "LFE SUB + L/R"; Does this configuration serve as the same purpose as Option 1 and selecting "Large" for Front and "None" for Sub??

Please give me some suggestions on hooking up my sub. Any commets appreciated!


Kai-Wei Jeng
www.kaiwei.unfranchise.com

botany

Hello, I too have a H/K receiver, but its the 520. I also have Rti70's for my fronts, CSi40 center, FXi50 for the rears, FXi30 side rears, and the PSW650 sub (front of the room), and PSW 202 used for the (rear room).
I am using (option 1) that is found in the PSW650 book. I have the fronts set to large and the rest of the speakers to small. In the Polk book that came with the PSW 650 this is the best way to hook-up the sub (The polk way). The sound is really great in movies and music.

Botany

botany

One more thing the sub's are set to none.

I hope this helps.

Botany

Kjeng

I've picked up the sub today. It was huge!!!


I will try both ways. Thanks!


Kai-Wei Jeng

Dr. Spec

Set ALL your speaks to small.
Set your filter point to 80 Hz.
Set your sub to on/yes.
Set the sub level in the AVR to -3.
Connect the sub out from the AVR to the LFE (unfiltered) jack on the PSW650.
Run the AVR speaker test tones at Master Volume 00 and calibrate all the surround speakers to 75 dB.
Run the sub test tone at MAster Volume 00 and adjust the plate amp on the 650 until the meter is reading 78-79 dB (on average).

Edit - use C-Weighted Slow on the SPL meter.

Doc

Kjeng

Dr. Spec,


This was my setup yesterday: hooked up the sub using speaker wire input. In bass management, Fronts are set to large, Center and Surrounds are small. Sub none. AVR master volume was set to -15dB and calibrated the 5 speakers to 75dB using C weight/slow on a digital SPL meter. I could not test the subwoofer tone since it was selected none and not hooked up to the LFE preout.

PSW 650 is placed behind the plane of my RTi 70. Drivers are at least 6 inches away from wall or entertainment center. Room is 15x12 with one open side to the nook and kitchen. When I play Peral Harbor, the bass was really powerful and shook the house. I thought the bass was really deep, but it was not as tight as I would have expected. Low pass crossover frequency was set between 60-80 Hz. It blends really well with the mains.

Is it because the size and placement of the sub and also dimension of the room that I don't get a tighter bass response? I will try your suggestion tonight.

"Run the sub test tone at MAster Volume 00 and adjust the plate amp on the 650 until the meter is reading 78-79 dB (on average)."

Do you mean adjust the voulme on the sub ?

"Set your filter point to 80 Hz." At the AVR? The THX cutoff frequency?

THanks for all your help!


Kai-Wei Jeng
www.kaiwei.unfranchise.com

Dr. Spec

OK, your volume control is different. If you are using -15 for 75 dB, then also use -15 for the sub, obviously.

Yes, leave the sub AVR setting at -3, and adjust the sub volume control until you get 78-79 dB. That's a good starting point for HT, but you may prefer it a bit hotter or cooler.

If you can alter your high pass filter freqency, pick 80 Hz - yes at the AVR. You will be doing all your filtering in the AVR and none of it at the subwoofer. Make sure to use the LFE input on the 650.

You will be sending the subwoofer the low-passed bass from every speaker, and also the LFE channel. There are a many sound technical reasons why this method is better performing and better sounding than any other for HT, but they take too long to explain and you will have to trust me because CSI just started. :-)

As for the sub not being "tight" enough - could be placement, could be the sub, maybe a little of both. Try the new method and see how you like it.

Doc

fireshoes

Hey Doc, with that receiver, he could probably set the fronts to large and sub to no, run front preouts to the sub and the back to the receiver's main-in, bypassing the receiver's crossover and using just the sub's. What's your opinion on that method? I would think it would be the best in theory. I'm not sure about reality though.

Kjeng

hi Doc,

This aftrenoon, I disconnected the "Polk Way" and used LFE input on PSW650 and LFE preout from my AVR8000.

I then set all speakers to small and bass cutoff at 80Hz. I set the master voulme to 0 dB and calibrated Front/Center/Surround to 75dB. Set sub to -3dB and calibrated to 78-79 dB.

From my understanding, if I use LFE input, then the knob on back of PSW650 for frequency adjustment will not interact with frequency from receiver (correct?) I auditioned Norah Jones/Live in New Orleans, Peral Harbour, Hebert Von Karajan's Classical music on DVD. I also poped in several CD with lots of bass. THe result? I like the new setup. The bass blends seamlessly with the main. Is this due to the fact that because I set all the speakers at "small?"

I am not much of a stereophile, but I must admit, the polk RTi 70 is just "okay" for a loudspeaker. It lacks the lower end of the frequency. By setting it small, it handles better the midrange and highs, correct?

Getting back to PSW650, I think because the room is small, and with all the furnitures and speakers, it limits the way standing wave travels!? When I listen to music, I usually set my volume at -25dB, and with movies at around -15dB. I have not really try to turn up the volume more. At these volumes, my floor and ceiling are already vibrating from the bass. If I turn up more, it would really rock the house. I wonder if the sub would sound different with a bigger room and louder volume.

Thanks for your help! WOuld love to hear more of your input!

Kai-Wei Jeng
www.kaiwei.unfranchise.com

Dr. Spec

Yes, you are correct - the LFE input on the PSW650 bypasses the filter control, which is exactly what you want when you are filtering at the AVR. Otherwise you can "double filter" which is a bad thing and creates a large depression in the FR at that point.

The RTi70 is a great speaker for HT and music when high passed. It lacks deep extension and also lacks air moving capability and is not as impressive running in a full range configuration.

There are basically two reasons why your rig sounds better:

1) Your AVR is no longer straining to send a full range, full current signal to the 650. When you set the speaks to Small, you are filtering before the amp stage and the load on the AVR becomes a piece of cake in comparison. You will now find the AVR to suddenly have far more guts and dynamic quality that its power rating would otherwise suggest.

2) The RTi70s are no longer trying to produce bass and mids and the same time, which causes Intermodulation Distortion in the drivers, particularly the woofer. Many enthusiasts report a considerable increase in midrange clarity when the speakers are high passed.

fireshoes - I'm against running the RTi70 on large because of the above-mentioned limitations of its design, and also because several sources of low bass (two towers run on Large and a sub) can (not always) interact with each other in bizarre ways and create nulls in the room where they otherwise would not be.

The 650 digs deeper and plays louder and is a better candidate to handle the low passed bass from the mains than the RTi70 is running on full range.

Doc

fireshoes

Hey Doc, the method I was referring to sends the full signal to the sub, gives it the bass, then sends the highs back to the receiver where the signal is amplified and sent to the mains. The sub's crossover is taking the low signal out so the towers would not be getting full range sound.

Dr. Spec

Oh, sorry, I misunderstood you. Yeah, I suppose that would work, but if you have a variable set point in the AVR for the high pass, it would seems like almost the same thing as setting the speaks to small.

If you don't have a variable high pass set point, then I can see your method having an advantage, at least in theory.

Doc