# PSW350 Placement/Phase Assistance...



## Osage_Winter (Apr 8, 2010)

I am running a rather "vintage" Polk PSW350 in my system, and while it has serviced me thus far through a few different systems, I recently re-installed it in a new system when we bought our new house less than a month ago.

Not really happy with the slam I have been experiencing since putting the sub in the new room, I spent a good deal of time today experimenting with placing it in a corner and adjusting the phase control; what I discovered was that placing it in the corner, with the port actually firing into the corner itself (so the sub is catty-cornered when looking at it) may have perhaps made the effect more "loose" and "sloppy" which was expected, but I can't really tell if it improved output or overall tactile slam at all. So, I switched the position back to where it was, directly to the left of the left front main (a Polk RTi12 tower) and ran various sequences off the _Haunting_ (1999) DVD which contains a great deal of ultra low sub bass on the DTS-ES soundtrack and did back-to-back comparisons. I couldn't really tell if one position sounded "better" than the other; from what I can hear, the position against the wall next to the left main channel may have made the bass a bit "tighter" and "more controlled," but with a bit less slam...

Now, with regard to phase, I was advised to leave this switch on "0" degrees (my PSW350 has a toggle for 0 or 180) and to keep the Low Pass Filter of the sub on its HIGHEST position because there is no bypass mode on it. On the 350, this level is "160Hz". While that seems a bit high to me, I jacked that up all the way. I experimented with switching the phase between 0 and 180, but honestly, I cannot tell if there's a difference...is this normal, for the phase not to make an audible difference in most cases? What should I keep it on then? The rear of the sub has the 180 degree position "suggested" by Polk with a white box indicator; is 180 or 0 correct? For reference, I am running my Onkyo receiver's LFE OUT direct with a single gold plated Monster RCA sub cable to the Polk sub's LFE UNFILTERED IN and keeping all crossovers in the receiver to 80Hz (main, center, surrounds); should this Low Pass knob on the sub make any difference where it's set?

As far as placement, if I can't really detect a difference between the corner or the wall next to the left main speaker, should I just leave it where it is, along the main wall next to the left channel? Would it be better not to leave it in the corner because of too much roll off and "boominess"?


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## glaufman (Nov 25, 2007)

Lots of questions here, I hope I get them all.. 
WRT the Low Pass Filter, assuming you're using a crossover in an upstream processor/AVR/BD then yes, leave the LPF on the sub all the way as high as it can go if there's no bypass/off setting. This control is generally for a different configuration, and the idea is to disable it as best as possible so it doesn't interfere with what the upstream crossover is doing.
As for the phase, it's very possible that the phase is as bad in the 0 setting as it is in the 180 setting. That could explain the no audible difference. In theory, you could play with the delays i nthe upstream AVR/processor to try and fine tune the phase, but people have mixed success with that. Sometimes the REW plot shows more differences than you can detect with your ears. Another thing to try would be playing not real world material but individual sine tones, and different frequencies at first just below, then at, then just above the crossover frequency. In such a case it'll be easier to detect nulls than peaks, but even this can be difficult depending on how bad the problem is. That's one of the best usages for REW. Run 2 sweeps, altering the phase between each sweep. The sweep that produces the smoothest curve in the crossover region is the best place to leave the switch.


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## Osage_Winter (Apr 8, 2010)

glaufman said:


> Lots of questions here, I hope I get them all..


Thanks much, Glaufman; I think you addressed most of them!



> WRT the Low Pass Filter, assuming you're using a crossover in an upstream processor/AVR/BD then yes, leave the LPF on the sub all the way as high as it can go if there's no bypass/off setting. This control is generally for a different configuration, and the idea is to disable it as best as possible so it doesn't interfere with what the upstream crossover is doing.


Okay; this is what I thought...

Yes, I am running the receiver's LFE PRE OUT to the sub's UNFILTERED PRE IN -- just one RCA link. Given this, the internal circuitry of the AVR should be handling the crossover duties, yes? So in this case, the suggestion is to turn the Low Pass knob on the sub all the way up? On the PSW350, this setting is "160Hz"...is this okay?

Truthfully, I never heard any difference between leaving this knob at a lower setting -- somewhere near the middle as that's where Polk has painted a white "indicator" suggesting this is where the knob "should be" -- and raising it to the maximum level that it will go (160Hz)...could this be because the Low Pass filter is being bypassed on the sub due to the fact that it's going PRE OUT/PRE IN?



> As for the phase, it's very possible that the phase is as bad in the 0 setting as it is in the 180 setting. That could explain the no audible difference. In theory, you could play with the delays i nthe upstream AVR/processor to try and fine tune the phase, but people have mixed success with that. Sometimes the REW plot shows more differences than you can detect with your ears. Another thing to try would be playing not real world material but individual sine tones, and different frequencies at first just below, then at, then just above the crossover frequency. In such a case it'll be easier to detect nulls than peaks, but even this can be difficult depending on how bad the problem is. That's one of the best usages for REW. Run 2 sweeps, altering the phase between each sweep. The sweep that produces the smoothest curve in the crossover region is the best place to leave the switch.


I'll try and play with the sine sweeps via the Spears & Munsil Blu-ray when I can, but if I don't discern any audible difference between the two phase settings, does it matter if I leave the switch to 0 or 180 degrees?

Thank you for your continued assistance, sir! :T

P.S. What part of New York are you in?


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## glaufman (Nov 25, 2007)

Osage_Winter said:


> Yes, I am running the receiver's LFE PRE OUT to the sub's UNFILTERED PRE IN -- just one RCA link. Given this, the internal circuitry of the AVR should be handling the crossover duties, yes? So in this case, the suggestion is to turn the Low Pass knob on the sub all the way up? On the PSW350, this setting is "160Hz"...is this okay?
> Yes, if the receiver is set to an 80Hz crossover, this is ok. Bypassed would be better, but since you don't have that, all the way up is as good as you can get.
> 
> 
> ...


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## Osage_Winter (Apr 8, 2010)

glaufman said:


> Doubtful. I don't see how the sub would know where it's input is coming from. If you're really curious, you could run sub only scans at different settings and see the knob working, or even faster, do it with the RTA function in REW and PN. In this case it's really a non-issue though.


I was under the assumption that if an LFE PRE IN is connected to the sub's rear, it just knows that it's being UNFILTERED and threfore it doesn't apply its own internal crossover...this isn't how the self powered subs work?



> You're Welcome! But My name's Greg, (Sir is my father).


Sorry! My apologies.



> NYC Metro area... click on "googlemap me" under my avatar...


Kewel. I am originally from Long Island. :T


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## glaufman (Nov 25, 2007)

Osage_Winter said:


> I was under the assumption that if an LFE PRE IN is connected to the sub's rear, it just knows that it's being UNFILTERED and threfore it doesn't apply its own internal crossover...this isn't how the self powered subs work?


Not really. They detect whether there's an input or not, and power down (mostly) if there isn't, and power on (usually) when there is, but it can't really tell what kind of input it's being fed from.


> Kewel. I am originally from Long Island. :T


Excellent. Which part? When did you leave?


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## Osage_Winter (Apr 8, 2010)

glaufman said:


> Not really. They detect whether there's an input or not, and power down (mostly) if there isn't, and power on (usually) when there is, but it can't really tell what kind of input it's being fed from.


From what I understand, a powered sub simply overrides any internal crossover it may do when it "senses" an unfiltered LFE input...but it's been suggested to me to simply keep the Low Pass knob all the way up on the back of my sub just to be CERTAIN. 

Still, I feel as though "160Hz" -- the maximum setting on my sub's knob -- seems too high. Is there anyone else who can confirm what this setting should be on?



> Excellent. Which part? When did you leave?


South Shore, near the Long Beach area...left around 2004 or so.


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## glaufman (Nov 25, 2007)

Osage_Winter said:


> From what I understand, a powered sub simply overrides any internal crossover it may do when it "senses" an unfiltered LFE input...


Still: no. It has no way of sensing whether the input is filtered or not. 


> but it's been suggested to me to simply keep the Low Pass knob all the way up on the back of my sub just to be CERTAIN.


It's not "just to be certain." It's to keep it doing as little harm as possible.


> Still, I feel as though "160Hz" -- the maximum setting on my sub's knob -- seems too high.


It would be too high if you weren't using a xover somewhere else, like in your AVR or Processor, or even some BD players. If you have a crossover elsewhere, the idea is setting this as high as possible makes it do as little as possible so it doesn't alter what's being done by the other device.
If you were simply hooking your sub up in parallel to your main speakers, that's one scenario where you would use this control to limit how much HF energy was going to the sub.


> South Shore, near the Long Beach area...left around 2004 or so.


You're kidding? Because you saw my pin there? I still own an apartment in LB on W.Broadway, across from the Hebrew Academy. Small world.


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## Osage_Winter (Apr 8, 2010)

glaufman said:


> Still: no. It has no way of sensing whether the input is filtered or not.
> 
> It's not "just to be certain." It's to keep it doing as little harm as possible.


Well, I'm as lost as confused as ever; now I really don't know where to keep this knob's setting because what you're telling me is contradicting every other piece of advice I've received on the subject. 

I'm going LFE OUT from the receiver to LFE IN (UNFILTERED) on the sub -- and I was told "to make sure" the sub isn't adding any additional crossing over, keep the Low Pass knob to its highest position, which, on my sub, is 160Hz...which brings me to this:



> It would be too high if you weren't using a xover somewhere else, like in your AVR or Processor, or even some BD players. If you have a crossover elsewhere, the idea is setting this as high as possible makes it do as little as possible so it doesn't alter what's being done by the other device.
> If you were simply hooking your sub up in parallel to your main speakers, that's one scenario where you would use this control to limit how much HF energy was going to the sub.


Okay...I think I understand this more...

So, definitely keep that Low Pass knob all the way up if I'm running LFE OUT/LFE in and doing crossover inside the receiver?



> You're kidding? Because you saw my pin there?


Huh??



> I still own an apartment in LB on W.Broadway, across from the Hebrew Academy. Small world.


That IS a small world -- I lived right across the from the Sands in Atlantic Beach actually. I used to hang in Long Beach all the time; I had cousins that lived on Florida Street, and a grandmother that lived near your apartment in the Crown able home there. :T


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## glaufman (Nov 25, 2007)

> So, definitely keep that Low Pass knob all the way up if I'm running LFE OUT/LFE in and doing crossover inside the receiver?


Yes.


> That IS a small world -- I lived right across the from the Sands in Atlantic Beach actually. I used to hang in Long Beach all the time; I had cousins that lived on Florida Street, and a grandmother that lived near your apartment in the Crown able home there. :T


Wow. My wife's first place was in East Atlantic Beach. I don't recognize the "Crown" I wonder what it is now... there's Hoffman, King David...
Oh, how I miss hanging out in the West End...


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## Osage_Winter (Apr 8, 2010)

glaufman said:


> Yes.


Okay...even if that highest position on my sub is 160Hz?



> Wow. My wife's first place was in East Atlantic Beach. I don't recognize the "Crown" I wonder what it is now... there's Hoffman, King David...
> Oh, how I miss hanging out in the West End...


Wow...indeed a small world. I had a friend that lived in East Atlantic Beach, on Clayton, Robert McCauley, and I would always get sandwiches and bagels from Beach Bagels on Beech Street, right across from C Town, Surfside Drugs and San Remo Pizzeria (the best pizza next to Gino's across from the LIRR station)...:T


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## glaufman (Nov 25, 2007)

Osage_Winter said:


> Okay...even if that highest position on my sub is 160Hz?


Yup, with an 80Hz crossover upstream, that should be just fine.


> Wow...indeed a small world. I had a friend that lived in East Atlantic Beach, on Clayton, Robert McCauley, and I would always get sandwiches and bagels from Beach Bagels on Beech Street, right across from C Town, Surfside Drugs and San Remo Pizzeria (the best pizza next to Gino's across from the LIRR station)...:T


Ah, Gino's! Their "special" slice is my favorite of all time. Haven't been there in ages. Beach Bagels is good, but on the wrong side of town for me... I always went to the Bagel Club in the EAST end...
FWIW, the Inn and the Saloon have both been renovated in recent years...


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## Osage_Winter (Apr 8, 2010)

glaufman said:


> Yup, with an 80Hz crossover upstream, that should be just fine.


What about if I lowered the mains' crossover points to 60Hz, as recommended to me by the Polk Audio forum?



> Ah, Gino's! Their "special" slice is my favorite of all time. Haven't been there in ages. Beach Bagels is good, but on the wrong side of town for me... I always went to the Bagel Club in the EAST end...
> FWIW, the Inn and the Saloon have both been renovated in recent years...


I hear ya...we always used to get pies at San Remo, too, with the owners' two daughters making the pies and from that point on, their taste went a bit downhill...

What about Minnesotas? Is it still there and is it still the biggest Hoochie Hangout in New York?

BTW are you Jewish by any chance? I was Bar Mitzvahed at the Sephardic Temple in Cedarhurst...


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## glaufman (Nov 25, 2007)

Osage_Winter said:


> What about if I lowered the mains' crossover points to 60Hz, as recommended to me by the Polk Audio forum?


No problem with the 160Hz setting on the sub. The idea is to put the corner frequency of the sub's LPF as far away as possible from the xover upstream in the AVR, so in this regard, 60Hz would work even better than 80Hz, but only WRT the 160Hz max corner for the LPF in the sub... 60Hz may be better or worse for the speakers and the sub combo in general, you can experiment with that, but again, as long as there's a crossover upstream in the AVR that your using, you turn the LPE control on the sub to as high a frequency as it'll go and leave it there, if it can't be bypassed altogether.


> I hear ya...we always used to get pies at San Remo, too, with the owners' two daughters making the pies and from that point on, their taste went a bit downhill...
> 
> What about Minnesotas? Is it still there and is it still the biggest Hoochie Hangout in New York?
> 
> BTW are you Jewish by any chance? I was Bar Mitzvahed at the Sephardic Temple in Cedarhurst...


Never been to San Remo... if I was that far west I was heading towards 5 towns or JFK... or (gasp) Jersey...

Haven't been in Minnesota's in years, but I imagine it's the same as it ever was...

As a matter of fact I am, but I grew up on the North Shore...


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## Osage_Winter (Apr 8, 2010)

glaufman said:


> No problem with the 160Hz setting on the sub. The idea is to put the corner frequency of the sub's LPF as far away as possible from the xover upstream in the AVR, so in this regard, 60Hz would work even better than 80Hz, but only WRT the 160Hz max corner for the LPF in the sub... 60Hz may be better or worse for the speakers and the sub combo in general, you can experiment with that, but again, as long as there's a crossover upstream in the AVR that your using, you turn the LPE control on the sub to as high a frequency as it'll go and leave it there, if it can't be bypassed altogether.


Okay...I have turned the knob all the way up on the Low Pass on the sub...

The issue I'm having now is, I tried running Audyssey tonight and it didn't really peg the system all that correctly; I had to change the mains and surrounds to something other than "Full Range" which is what the receiver set them to, and had to adjust some trim levels...is it okay to override Audyssey and manually adjust calibration?




> Never been to San Remo... if I was that far west I was heading towards 5 towns or JFK... or (gasp) Jersey...


I hear ya...5 Towns was my stomping ground for a long time; went to Lawrence High School. Always took Rockaway Turnpike past the Sherwood Diner and into JFK... 



> Haven't been in Minnesota's in years, but I imagine it's the same as it ever was...


My, was that place a scene...


> As a matter of fact I am, but I grew up on the North Shore...


Gotcha. I had a good deal of activities over the years on the North Shore...had a girlfriend of 11 years who lived in Roslyn...my college roommate from Adelphi lived in Cold Spring Harbor...another good college friend of mine lived in Northport...I worked in Huntington for a while at a public relations firm...


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## glaufman (Nov 25, 2007)

Osage_Winter said:


> Okay...I have turned the knob all the way up on the Low Pass on the sub...


Good!


> The issue I'm having now is, I tried running Audyssey tonight and it didn't really peg the system all that correctly; I had to change the mains and surrounds to something other than "Full Range" which is what the receiver set them to, and had to adjust some trim levels...is it okay to override Audyssey and manually adjust calibration?


The "full range" thing is a sticking point for me with Audyssey. Audyssey says that for whatever reason, how the AVR sets this setting is up to the MFR, not up to Audyssey. It's most definitely ok, and recommended, to override this setting. As for the levels, I'd want to see the scans, but if you're sure what Audyssey did was wrong, then...


> I hear ya...5 Towns was my stomping ground for a long time; went to Lawrence High School. Always took Rockaway Turnpike past the Sherwood Diner and into JFK...
> 
> Gotcha. I had a good deal of activities over the years on the North Shore...had a girlfriend of 11 years who lived in Roslyn...my college roommate from Adelphi lived in Cold Spring Harbor...another good college friend of mine lived in Northport...I worked in Huntington for a while at a public relations firm...


Hah! My Dad went to Adelphi!, and I grew up in Huntington, and I know the Northport docks and waters like the back of my hand!


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## glaufman (Nov 25, 2007)

How about that $0.99 movie theater in Northport?


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## Osage_Winter (Apr 8, 2010)

glaufman said:


> The "full range" thing is a sticking point for me with Audyssey. Audyssey says that for whatever reason, how the AVR sets this setting is up to the MFR, not up to Audyssey. It's most definitely ok, and recommended, to override this setting. As for the levels, I'd want to see the scans, but if you're sure what Audyssey did was wrong, then...


Indeed, I have also learned this is something manufacturers -- i.e. Onkyo -- implement in the design phase, thus Audyssey "sees" the speakers as Full Range...it's just so strange how the system "read" my speaker array...okay, the Polk RTi12 monsters could be "seen" as "full range" but it also pegged my center at an 80Hz rolloff, and then identified my surrounds (in celing SpeakerCrafts) as "full range" as well. 

I since changed the Polk RTi12's to roll off at 60Hz, the center to 80 and the surrounds to 80...is there any way you can recommend or confirm these settings, taking my environment out of the equation for a moment?

In other words, I'm running tower RTi12's up front for mains, so I was advised by "members" of the Polk Forum to run these at 60Hz that way they can flex some muscle and still feed frequencies at the 80Hz stage to the sub...I originally had the RTi12's at 80Hz but since changed them to 60 based on this tip...do you agree for speakers the size of the 12's?

Also, what about my Polk CSi30 center and the SpeakerCraft surrounds? Can these be left to roll off at 80?



> Hah! My Dad went to Adelphi!, and I grew up in Huntington, and I know the Northport docks and waters like the back of my hand!


Excellent! A very small world. What year did your dad graduate? I graduated from there in '96.


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## Osage_Winter (Apr 8, 2010)

glaufman said:


> How about that $0.99 movie theater in Northport?


I wasn't that familiar with Northport, only went there to visit my friend occasionally...


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## glaufman (Nov 25, 2007)

Osage_Winter said:


> Indeed, I have also learned this is something manufacturers -- i.e. Onkyo -- implement in the design phase, thus Audyssey "sees" the speakers as Full Range...it's just so strange how the system "read" my speaker array...okay, the Polk RTi12 monsters could be "seen" as "full range" but it also pegged my center at an 80Hz rolloff, and then identified my surrounds (in celing SpeakerCrafts) as "full range" as well.
> 
> I since changed the Polk RTi12's to roll off at 60Hz, the center to 80 and the surrounds to 80...is there any way you can recommend or confirm these settings, taking my environment out of the equation for a moment?
> 
> ...


I haven't looked up the specs, but generally, 80Hz is a good setpoint even for capable speakers, unless you're very adept at bass localization.


> Excellent! A very small world. What year did your dad graduate? I graduated from there in '96.


mid 60s...


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## ToBeFrank (Feb 27, 2010)

Osage_Winter said:


> I'm going LFE OUT from the receiver to LFE IN (UNFILTERED) on the sub -- and I was told "to make sure" the sub isn't adding any additional crossing over, keep the Low Pass knob to its highest position, which, on my sub, is 160Hz...which brings me to this:


I just sold my 350 a couple weeks ago. The LFE IN on it bypasses the LPF. It doesn't matter where the LPF knob is set. From the manual:


> Connect a single RCA cable from the “SUB OUT” of your electronics to the LFE input of the subwoofer. This input bypasses the sub- woofer’s variable low pass filter and relies on the filter built into your electronics.


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## Osage_Winter (Apr 8, 2010)

glaufman said:


> I haven't looked up the specs, but generally, 80Hz is a good setpoint even for capable speakers, unless you're very adept at bass localization.


Yes, it seems that Jungle Jack is advising me of the same thing in my other thread in the speakers section; he also suggests 80Hz across the board, unless I am mistaken, but there's something that just doesn't rub me the right way about leaving speakers as big as the RTi12's crossed over at 80...almost like the bass these things can produce won't really be taken advantage of this way. I understand this would be a massive relief from my low powered amp, which I am all for, but I was hoping to get some more punch from the mains along with the sub...

Would crossing these over at 80 allow some punch to develop from the mains...at least a little?



> mid 60s...


Wow...way before my time! I wasn't even born yet! :blink:


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## Osage_Winter (Apr 8, 2010)

ToBeFrank said:


> I just sold my 350 a couple weeks ago. The LFE IN on it bypasses the LPF. It doesn't matter where the LPF knob is set. From the manual:


Thank You!

This was valuable information; I no longer have my 350 manual, so this was helpful...

Why did you sell your 350? Did you go with something "better" like an SVS, which I hope to, someday, move on up to? As far as I am concerned, Polk does everything right except for subs.

Do you have any phase tips, whether it should be on 0 or 180? Either position doesn't seem to matter, as far as I can tell, in my room/system...


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## glaufman (Nov 25, 2007)

ToBeFrank said:


> I just sold my 350 a couple weeks ago. The LFE IN on it bypasses the LPF. It doesn't matter where the LPF knob is set. From the manual:


If there're 2 separate inputs, one that bypasses the LPF and one that doesn't, that's a different story. My point is that the sub can't "sense" and "determine for itself" whether to bypass the LPF or not.


Osage_Winter said:


> there's something that just doesn't rub me the right way about leaving speakers as big as the RTi12's crossed over at 80...almost like the bass these things can produce won't really be taken advantage of this way. I understand this would be a massive relief from my low powered amp, which I am all for, but I was hoping to get some more punch from the mains along with the sub...


Tough for a lot of people to get over. Other than relieving power off the main amps, some other reasons to do it are:
1: Good place for emitting bass is usually not the same as a good place for imaging. Therefore, it's advantageous to use the speakers for imaging, and something else for bass.
2: Keep in mind that even crossed over at 80Hz, the mains will still be emitting energy below that. Crossover isn't a brick wall, it's a gradual rolloff. 
3: Because of #2 above, sometimes you have to be careful setting 80Hz speakers with an 80Hz crossover. The crossover rolloff combines with the speakers natural rolloff, and results in a less than optimal result. Ideally, the crossover would be set 1 octave above the natural low end of the speaker, with 1/2 octave being an often more practical acceptable compromise. Another possibility is an AVR whose crossover purposely works with the rolloff of the mains...


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## ToBeFrank (Feb 27, 2010)

Osage_Winter said:


> This was valuable information; I no longer have my 350 manual, so this was helpful...


You can download the manual here: http://www.polkaudio.com/downloads/manuals/home/PSW250_350_450Manual.pdf



> Why did you sell your 350? Did you go with something "better" like an SVS, which I hope to, someday, move on up to? As far as I am concerned, Polk does everything right except for subs.


I was watching Cloverfield and the 350 was bottoming out even at -12dB. Upgrade-itis kicked in and I upgraded my entire home theater. I went with a SVS PC12-Plus. The 350 served me well for the 8 years I had it but it's nothing compared to the SVS. Movies are a whole new experience. You won't regret the upgrade!



> Do you have any phase tips, whether it should be on 0 or 180? Either position doesn't seem to matter, as far as I can tell, in my room/system...


Before I set up my measuring rig I used an SPL meter and a calibration DVD. The DVD had a test for setting the phase. I could never tell a difference between the two settings and just set it (unscientifically) to 180 since the 350 was on the opposite side of the room. If you can't hear a difference I wouldn't worry about it. With only two settings it's doubtful either will be optimal anyway.


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## Osage_Winter (Apr 8, 2010)

ToBeFrank said:


> You can download the manual here: http://www.polkaudio.com/downloads/manuals/home/PSW250_350_450Manual.pdf


Thanks...



> I was watching Cloverfield and the 350 was bottoming out even at -12dB.


Do you mean on your AVR or processor's calibration setting for the sub?

That's surprising -- my 350 bottoms out on scenes from DVDs like _Attack of the Clones_ if it's on, say, +6 or +7dB, but never in the negative values. 



> Upgrade-itis kicked in and I upgraded my entire home theater. I went with a SVS PC12-Plus. The 350 served me well for the 8 years I had it but it's nothing compared to the SVS. Movies are a whole new experience. You won't regret the upgrade!


I bet -- how expensive is that SVS PC12?



> Before I set up my measuring rig I used an SPL meter and a calibration DVD. The DVD had a test for setting the phase. I could never tell a difference between the two settings and just set it (unscientifically) to 180 since the 350 was on the opposite side of the room. If you can't hear a difference I wouldn't worry about it. With only two settings it's doubtful either will be optimal anyway.


Oh, so, if my 350 is on the same front wall as the TV, main channels and equipment rack, is it OK for me to leave the switch to 0?


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## Osage_Winter (Apr 8, 2010)

glaufman said:


> If there're 2 separate inputs, one that bypasses the LPF and one that doesn't, that's a different story. My point is that the sub can't "sense" and "determine for itself" whether to bypass the LPF or not.


Okay, but we were trying to determine if on _my_ specific sub there was something that "told" the sub to bypass the internal low pass control based on whether or not something was plugged into that LFE unfiltered in jack...that's why I wanted to know, concretely, if by plugging an LFE out into that jack, from the AVR, it automatically bypasses the sub's internal crossover...which apparently it does.



> Tough for a lot of people to get over. Other than relieving power off the main amps, some other reasons to do it are:
> 1: Good place for emitting bass is usually not the same as a good place for imaging. Therefore, it's advantageous to use the speakers for imaging, and something else for bass.
> 2: Keep in mind that even crossed over at 80Hz, the mains will still be emitting energy below that. Crossover isn't a brick wall, it's a gradual rolloff.
> 3: Because of #2 above, sometimes you have to be careful setting 80Hz speakers with an 80Hz crossover. The crossover rolloff combines with the speakers natural rolloff, and results in a less than optimal result. Ideally, the crossover would be set 1 octave above the natural low end of the speaker, with 1/2 octave being an often more practical acceptable compromise. Another possibility is an AVR whose crossover purposely works with the rolloff of the mains...


While I don't really understand why it would be tough for other people to "get over" outside of me and my obssessive tendencies, I want to be certain that the RTi12 models can "flex" a bit at 60Hz while feeding some additional lower information to the subwoofer. :scratch:


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## ToBeFrank (Feb 27, 2010)

Osage_Winter said:


> Do you mean on your AVR or processor's calibration setting for the sub?


My main volume is calibrated such that the 0dB setting is reference level. The 350 was bottoming out at -12dB from reference.



> I bet -- how expensive is that SVS PC12?


About a grand.



> Oh, so, if my 350 is on the same front wall as the TV, main channels and equipment rack, is it OK for me to leave the switch to 0?


Probably. But like I said it's unscientific unless you measure it. If it sounds fine to you I wouldn't stress about it.


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## Osage_Winter (Apr 8, 2010)

ToBeFrank said:


> My main volume is calibrated such that the 0dB setting is reference level. The 350 was bottoming out at -12dB from reference.


Okay; so, see, on some AVRs and processors -- such as the way Onkyo implements their designs -- there is a speaker calibration range from -12dB to +12dB. On Onkyo receivers, the sub calibration actually goes lower than -12dB; I think it goes down to -15dB or so. Regardless, you're saying that at a calibration of -12dB from the 0dB reference point the sub was still bottoming out, yes?

I don't have my speakers calibrated to reference points, and my receiver doesn't do relative volume in scale, only absolute; I just adjust trim levels to where I've always been comfortable with them, never reaching the "+12dB" maximum though -- given this kind of scale and setup, as I said, discs like _Attack of the Clones_ used to severely bottom out my PSW350 during the senator ship explosion sequence but that was when the sub was pushed into the "+7dB" or so area -- I had to turn that down! 



> About a grand.


Not bad...perhaps I will look into that. Can you send me a link to that specific model? 



> Probably. But like I said it's unscientific unless you measure it. If it sounds fine to you I wouldn't stress about it.


Thanks. :T


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## glaufman (Nov 25, 2007)

Osage_Winter said:


> Okay, but we were trying to determine if on _my_ specific sub there was something that "told" the sub to bypass the internal low pass control based on whether or not something was plugged into that LFE unfiltered in jack...that's why I wanted to know, concretely, if by plugging an LFE out into that jack, from the AVR, it automatically bypasses the sub's internal crossover...which apparently it does.


There's nothing that "tells" the sub it's filtered or not. What I missed is that there's another input that bypasses the LPF. It's just wired differently. "Automatic" implies some intelligence, which isn't there.


> While I don't really understand why it would be tough for other people to "get over" outside of me and my obssessive tendencies, I want to be certain that the RTi12 models can "flex" a bit at 60Hz while feeding some additional lower information to the subwoofer. :scratch:


Same reason it's tough for you  You can set the xover to 60 if you like. With the publlished FR, the speaker can do it. Whether the acoustics work you'll have to see. Whether the amp'll do it you'll have to see.


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## Osage_Winter (Apr 8, 2010)

glaufman said:


> There's nothing that "tells" the sub it's filtered or not. What I missed is that there's another input that bypasses the LPF. It's just wired differently. "Automatic" implies some intelligence, which isn't there.


It seems that by plugging in a subwoofer cable to the "LFE UNFILTERED IN," the sub's internal low pass filter is "bypassed;" I keep saying "automatically," but it's simply the best way I can describe what's going on here. Either way, that knob doesn't work on the sub once something is connected to LFE pre-in. 



> Same reason it's tough for you  You can set the xover to 60 if you like. With the publlished FR, the speaker can do it. Whether the acoustics work you'll have to see. Whether the amp'll do it you'll have to see.


Does dropping the crossover to 60Hz for these very large floor standing speakers allow them to play a bit deeper with their three woofer arrangement in each tower?


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## glaufman (Nov 25, 2007)

Osage_Winter said:


> It seems that by plugging in a subwoofer cable to the "LFE UNFILTERED IN," the sub's internal low pass filter is "bypassed;" I keep saying "automatically," but it's simply the best way I can describe what's going on here. Either way, that knob doesn't work on the sub once something is connected to LFE pre-in.


Perhaps I'm being a little nit-picky. :dontknow: 


> Does dropping the crossover to 60Hz for these very large floor standing speakers allow them to play a bit deeper with their three woofer arrangement in each tower?


As long as your talking the xover upstream from the speakers/sub, yes, it will send more lower frequency content to the towers than setting it to 80Hz. That may or may not make it sound better/worse/same. If the scans or your ears say it's better at 80, then I would leave it there and try to get over it. If the scans/ears say it's the same or better at 60, then there's no issue.


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## Osage_Winter (Apr 8, 2010)

glaufman said:


> Perhaps I'm being a little nit-picky. :dontknow:


It's all good. :T



> As long as your talking the xover upstream from the speakers/sub, yes, it will send more lower frequency content to the towers than setting it to 80Hz.


I'm referring to _inside the AVR_ in the crossover frequency setup menu, setting the "Fronts" or "Mains" to "60Hz" for rolloff...



> That may or may not make it sound better/worse/same. If the scans or your ears say it's better at 80, then I would leave it there and try to get over it. If the scans/ears say it's the same or better at 60, then there's no issue.


Gotcha. I am discussing this very thing in the Speakers section with some folks; will report back with any changes in quality with the crossover at 60...

Thanks for your assistance thus far! :T


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## glaufman (Nov 25, 2007)

Osage_Winter said:


> I'm referring to _inside the AVR_ in the crossover frequency setup menu, setting the "Fronts" or "Mains" to "60Hz" for rolloff...


That's the spot!


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