PSW350 Phase/Low Pass Settings...In Conjunction With RTi12's

Mike LoManaco

Figured I would re-post this in the Subwoofer section for more proper content recognition as opposed to the general Speakers area; please forgive the double posting.

Okay, so the RTi12's will probably be installed this week, and I want to get the optimum settings on the rear of my PSW350 as it relates to working with the 12's; the two settings I'm concerned with at the back of the 350 are PHASE and LOW PASS. I'm figuring PHASE will be okay at 0 degrees, but the LOW PASS knob on this sub goes from somewhere around 60Hz to 160Hz, with no BYPASS option. What's the best way to set the LOW PASS? Would it be to keep it at the highest setting on the knob, which would be 160Hz?

In my Onkyo 605's speaker setup, I will be keeping all the channels rolled off at 80Hz, and the sub will be connected via the one RCA Unfiltered Input, so would the optimum LOW PASS setting on the back of the 350 be 160Hz? This seems a little high; should it be all the way up?

Thanks again for all the continued assistance.

Knucklehead

Thats one heckuva set-up your putting together Mike. Someone correct me if Im wrong, but if you have your AVR set at 80hz, you can turn your sub gain all the way up because the AVR will only send signals to the sub that are 80hz and below if im not mistaken....although I could be wrong here. I think my AVR is set to roll off at 70hz, Ill have to check tonight.

cnh

Mike,

The question is, is that sub IN filtered or unfiltered....??

If it is UNFILTERED! The sub crossover does NOT function and the AVR filters everything just ONCE!


It won't matter what you set the sub crossover at, it does not do anything unless you're using a 'filtered' in!

cnh

Knucklehead

cnh, how do you tell if your sub is filtered? Sorry for the dumb question.

cnh

Knucklehead wrote: »

cnh, how do you tell if your sub is filtered? Sorry for the dumb question.

It will usually be identified as such on back of the sub...if you have an unfiltered in--it will say so...or it will be marked LFE in (unfiltered). If it is not so labelled you must check your manual which WILL specify what kind of ins your sub has, sometimes it my say filter Bypass instead. But it is important to know what you have or else you run into the problems Kuntasensei mentioned in Mike's other thread.

cnh

Knucklehead

cnh wrote: »

It will usually be identified as such on back of the sub...if you have an unfiltered in--it will say so...or it will be marked LFE in (unfiltered). If it is not so labelled you must check your manual which WILL specify what kind of ins your sub has, sometimes it my say filter Bypass instead.

cnh

Gotcha, Thank You.

wutadumsn23

Direct from the Polk product page for the PSW350.


"The PSW350 features:


10-inch direct radiating subwoofer driver for deep bass
Dual flared ports for low distortion
High current power amplifier
Magnetically shielded for safe placement near your TV
Auto on/off circuit that automatically turns your subwoofer on when it senses a program signal. When no signal is present, the amplifier turns off within 15 minutes
Unfiltered LFE input for use with low pass filtered subwoofer output jacks
Adjustable lowpass crossover, phase switch and volume control allows perfect blending with any main speaker."

So it looks like the PSW350 is unfiltered.

-Jeff

cnh

Thanks Jeff,

Wow! That's an 'interesting' wording? Unfiltered for use with FILTERED output jacks!

Which output jacks does that refer too, I wonder? Without seeing the back of the sub...it's not clear!


cnh

wutadumsn23

Yeah, I thought was kinda weird too, had to make sure I didn't mess it up when I pasted it, lol. Can't find a pic. of the back panel though.

-Jeff

comfortablycurt

The low pass filtered subwoofer output jacks would be the LFE outputs of an AVR.;)

The 350 is filtered, but only when using the filtered inputs. The LFE input would would be the unfiltered input, where as line level is filtered by the subs internal XO.


Your AVR will be taking care of all of the filtering. Turn the crossover on the sub all the way up to avoid double filtering the signal. Cross the sub over at 120hz(IMO) in your AVR's settings, and you'll be good to go. 80hz is too low of a setting IMO. Dolby spec'd soundtracks have LFE content all the way up to 120 hz anyway, and by setting the XO at a lower point than this, you're missing out on some of it.

Phase will most likely be 0, but there's absolutely no way for us to tell you that when you don't even have your gear set up yet. Phasing all depends on the room, placement, and other factors. You're going to have to flip it back and forth and decide what sounds best to your ears.

Knucklehead

Ok, so my M&K sub is good from 20hz to 200hz......If I have my AVR is
set to 80hz won't the R50's handle anything above that?

concealer404

Knucklehead wrote: »

Ok, so my M&K sub is good from 20hz to 200hz......If I have my AVR is
set to 80hz won't the R50's handle anything above that?

Not necessarily. The LFE track is separated from the L/R front signals. You'll be missing out on the LFE signal ONLY from 80hz to 120hz.

That said, what i do not like about doing this (though i assume there's receivers out there that can get around it) is that when you set that filter, your mains will only handle 120hz and above. If i were using my Paradigms in an HT setting, i wouldn't want that, since they're good to 80hz and well below without strain.

kuntasensei

comfortablycurt wrote: »

The low pass filtered subwoofer output jacks would be the LFE outputs of an AVR.;)

Just so we're clear, there is no LFE output on an AVR. There's a subwoofer output, which contains both the LFE channel and the summed bass redirected from the other channels. It sounds like a minor niggle, but a lot of confusion is caused by calling it an LFE output.

comfortablycurt wrote: »

Your AVR will be taking care of all of the filtering. Turn the crossover on the sub all the way up to avoid double filtering the signal. Cross the sub over at 120hz(IMO) in your AVR's settings, and you'll be good to go. 80hz is too low of a setting IMO. Dolby spec'd soundtracks have LFE content all the way up to 120 hz anyway, and by setting the XO at a lower point than this, you're missing out on some of it.

120Hz is too high to cross your speakers over to the sub, because 120Hz bass becomes directional, meaning your ears will hear it coming from the subwoofer itself instead of the individual channels. 80Hz isn't just a number THX pulled out of the air - it's the approximate point where human hearing begins to lose directionality with bass. Fortunately for Mike (and users of most modern AVRs), his Onkyo has both crossover settings for the individual channels AND a low pass filter of the LFE channel (which people commonly mistake as a crossover of the subwoofer, which it is not). Older AVRs didn't give you that much control and tended to low pass the entire summed subwoofer output at the lowest crossover point you set for any of the individual channels... but that's not the case for Mike.

An important note: The LPF of LFE setting is ONLY there for THX compatibility. Older Onkyos default this to 80Hz to suit the use of a THX-spec'd subwoofer. However, the proper setting of the LPF of LFE is 120Hz, as this allows the full bandwidth of the LFE channel to pass through to the subwoofer. You can then set individual channels to 80Hz, meaning the individual channels will carry all the directional bass for each channel and hand off the non-directional bass to your subwoofer, which will also be passed the entire 20-120Hz of the LFE channel. LPF of LFE does not affect any of the bass management from the other channels. Now do you see why it's important to differentiate between "LFE" and "subwoofer"?

comfortablycurt wrote: »

Phase will most likely be 0, but there's absolutely no way for us to tell you that when you don't even have your gear set up yet. Phasing all depends on the room, placement, and other factors. You're going to have to flip it back and forth and decide what sounds best to your ears.

If he's using Audyssey 2EQ, odds are that 0 will be the right setting. Audyssey's equalization in the time domain and setting of each channel's delay based on acoustic distance does a pretty solid job of lining up the phase correlation between the subwoofer and speakers. If he's not using Audyssey's equalization, the best method is to play an 80Hz tone in the main channels with the speakers crossed over at 80Hz and flip the phase switch back and forth to see which setting is loudest in the main listening position.

It's a shame Mike has me on ignore. Somebody quote me.

comfortablycurt

kuntasensei wrote: »

Just so we're clear, there is no LFE output on an AVR. There's a subwoofer output, which contains both the LFE channel and the summed bass redirected from the other channels. It sounds like a minor niggle, but a lot of confusion is caused by calling it an LFE output.

Ok...you've got me by a technicality, but the subwoofer output is there for the sole purpose of outputting an LFE signal(as well as re-directed bass from other channels), so for lack of a better word, I simply call it the LFE output. Call it what you want, but we're both talking about the same output.;)

120Hz is too high to cross your speakers over to the sub, because 120Hz bass becomes directional, meaning your ears will hear it coming from the subwoofer itself instead of the individual channels. 80Hz isn't just a number THX pulled out of the air - it's the approximate point where human hearing begins to lose directionality with bass. Fortunately for Mike (and users of most modern AVRs), his Onkyo has both crossover settings for the individual channels AND a low pass filter of the LFE channel (which people commonly mistake as a crossover of the subwoofer, which it is not). Older AVRs didn't give you that much control and tended to low pass the entire summed subwoofer output at the lowest crossover point you set for any of the individual channels... but that's not the case for Mike.

An important note: The LPF of LFE setting is ONLY there for THX compatibility. Older Onkyos default this to 80Hz to suit the use of a THX-spec'd subwoofer. However, the proper setting of the LPF of LFE is 120Hz, as this allows the full bandwidth of the LFE channel to pass through to the subwoofer. You can then set individual channels to 80Hz, meaning the individual channels will carry all the directional bass for each channel and hand off the non-directional bass to your subwoofer, which will also be passed the entire 20-120Hz of the LFE channel. LPF of LFE does not affect any of the bass management from the other channels. Now do you see why it's important to differentiate between "LFE" and "subwoofer"?

Here's where you're confusing me...You're saying that 80hz is the ideal XO point, but 120 hz is better, because there's LFE information all the way up to 120 hz anyway?

I think I was basically suggesting the same thing you are. 120hz crossover point for the sub, with 80hz crossover points on all the other speakers. That's how my setup has been for a long time, and I've found it to work best with several different speakers.

If he's using Audyssey 2EQ, odds are that 0 will be the right setting. Audyssey's equalization in the time domain and setting of each channel's delay based on acoustic distance does a pretty solid job of lining up the phase correlation between the subwoofer and speakers. If he's not using Audyssey's equalization, the best method is to play an 80Hz tone in the main channels with the speakers crossed over at 80Hz and flip the phase switch back and forth to see which setting is loudest in the main listening position.

I've never had to really mess with the phase when I've run Audyssey on my 606(which is basically the same receiver). I've always just set the subs phase to 0, then run Audyssey. I'll always try flipping the phase switch just in case, but 0 has been best every time.

It's a shame Mike has me on ignore. Somebody quote me.

Quoted.;)

kuntasensei

comfortablycurt wrote: »

I think I was basically suggesting the same thing you are. 120hz crossover point for the sub, with 80hz crossover points on all the other speakers.

In that case, we're saying the same thing, but the confusion lies in your use of the terminology. A crossover consists of two filters - a low pass and a high pass. LPF of LFE is not a crossover, because it is a single filter that does not affect the other channels. You're not setting a crossover point when you change the low pass filter of the LFE channel, nor are you setting an overall filter for the summed subwoofer output (because you could have LPF of LFE at 120Hz and still cross your speakers over above that point if you chose to - though you really shouldn't).

Thanks for quoting me.

kuntasensei

comfortablycurt wrote: »

Here's where you're confusing me...You're saying that 80hz is the ideal XO point, but 120 hz is better, because there's LFE information all the way up to 120 hz anyway?

I should clarify. The LFE channel is brickwall filtered at 120Hz during encoding, which is why it's the ".1" channel in 5.1 (so called by Prof. Tomlinson Holman of THX, now of Audyssey). As I said, however, bass begins to become directional above 80Hz, so why would you want the 80-120Hz information in the LFE channel passed to your subwoofer? The immediate logic would be, "Doesn't that make it easy to localize?"

The answer is no, because mixers don't place anything of significant energy above 80Hz in the LFE channel specifically because they don't want it to be easy to localize. So you're thinking now, "Then why not set LPF of LFE to 80Hz?" The reason is that our ears perceive the tone of deep bass primarily based on its harmonics. So while the majority of energy in the LFE channel will be below 80Hz, there are harmonics above that point that, while not of significant energy to make your sub easy to localize, will lend the sub-80Hz content its specific tone. A good example of this is Sauron's death at the beginning of LOTR. There's a sweeping bass tone that is partially in the main channels but primarily in the LFE channel. With a capable subwoofer, you can play this scene with LPF of LFE at 80Hz and 120Hz and hear a distinct difference in the perceived tone of that bass sweep.

All that said, it's a VERY minor niggle, and one that most people wouldn't hear with 90% of LFE content. Setting LPF of LFE to 120Hz merely ensures that you aren't filtering any of the LFE information that the mixer intentionally placed in that channel.

comfortablycurt

kuntasensei wrote: »

In that case, we're saying the same thing, but the confusion lies in your use of the terminology. A crossover consists of two filters - a low pass and a high pass. LPF of LFE is not a crossover, because it is a single filter that does not affect the other channels. You're not setting a crossover point when you change the low pass filter of the LFE channel, nor are you setting an overall filter for the summed subwoofer output (because you could have LPF of LFE at 120Hz and still cross your speakers over above that point if you chose to - though you really shouldn't).

Thanks for quoting me.

kuntasensei wrote: »

I should clarify. The LFE channel is brickwall filtered at 120Hz during encoding, which is why it's the ".1" channel in 5.1 (so called by Prof. Tomlinson Holman of THX, now of Audyssey). As I said, however, bass begins to become directional above 80Hz, so why would you want the 80-120Hz information in the LFE channel passed to your subwoofer? The immediate logic would be, "Doesn't that make it easy to localize?"

The answer is no, because mixers don't place anything of significant energy above 80Hz in the LFE channel specifically because they don't want it to be easy to localize. So you're thinking now, "Then why not set LPF of LFE to 80Hz?" The reason is that our ears perceive the tone of deep bass primarily based on its harmonics. So while the majority of energy in the LFE channel will be below 80Hz, there are harmonics above that point that, while not of significant energy to make your sub easy to localize, will lend the sub-80Hz content its specific tone. A good example of this is Sauron's death at the beginning of LOTR. There's a sweeping bass tone that is partially in the main channels but primarily in the LFE channel. With a capable subwoofer, you can play this scene with LPF of LFE at 80Hz and 120Hz and hear a distinct difference in the perceived tone of that bass sweep.

All that said, it's a VERY minor niggle, and one that most people wouldn't hear with 90% of LFE content. Setting LPF of LFE to 120Hz merely ensures that you aren't filtering any of the LFE information that the mixer intentionally placed in that channel.

Alright...So I think we were both suggesting the same thing, just in different words. Your HT terminology is much better than mine.;) Makes more sense now...thanks for clearing it up.:)

cnh

xcapri is right...all the info above is great and also informative...but it's only going to make Mike ask about 3 dozen more questions.

Also, Kuntasensei, you say that Mike has you on ignore? Does that have something to do with all the flack, a while back, about his movie reviews?

And just to clarify one more thing....according to both Polk and yours truly....that sub has an unfiltered in...which renders the sub frequency settings knob on the sub 'useless'--are we in agreement there? Hence all the adjustments above are AVR based.

Because if we don't agree about that then we need to discuss it further.



cnh

kuntasensei

cnh wrote: »

Also, Kuntasensei, you say that Mike has you on ignore? Does that have something to do with all the flack, a while back, about his movie reviews?

Yeah, but I have no problem with him personally and am still willing to help.

cnh wrote: »

And just to clarify one more thing....according to both Polk and yours truly....that sub has an unfiltered in...which renders the sub frequency settings knob on the sub 'useless'--are we in agreement there? Hence all the adjustments above are AVR based.

Yes, as long as he's using the unfiltered LFE in and not the line ins, the frequency knob on the PSW350 should do absolutely nothing. But for peace of mind, I say turn it to its max anyway, just to be sure.

Mike LoManaco

Unfortunately, cnh is right about having to now ask more questions -- but I won't ask quite as many as he suggested in that post...;)

So now there's a bit of confusion with the hookup; I'll be sending the LFE signal from the 605 out of its "SUBWOOFER OUT" into the 350's LFE IN...using this method, is it still advised to crank the LOW PASS knob up to 160Hz (the maximum on the rear of the sub) and let the receiver do the bass management?

160 just seemed a bit high to me -- furthermore, I'm still wondering what those rolloff settings should be for the RTi12 mains. Normally, I'd use 80Hz across the board, but the 12's can add some rumble, so am I better with another frequency for the left/right mains?

Mike LoManaco

Here's another query to ponder, as well...

Would corner-loading the sub yield maximum output in terms of LFE energy waves? I think I have a spot to the left of the wall unit (that arrives tomorrow) in the left corner that can be used for the PSW350, katty-cornered in there, and I understand there is great debate over this placement matter. Heck, I've found massive discrepencies in placement during my review sessions over the years. But I figured I'd ask some of you folks that have had experience with models like the PSW350 and see what you think of corner-loading the sub...

Should this greatly increase the energy wave, putting it in the corner, that is?

cnh

The idea of just turning the sub crossover to its max is just to play it safe....it has no effect...but just in case....if you leave it at its highest this will allow the AVR to send it what it wants! So don't worry about that, just do it and forget it.

As for corner loading, as you may know, yes, room boundaries increase the subs db levels but at the expense of the quality of the bass...it's a trade off. More bass means less controlled bass.

The best way to find the ideal spot for you sub...is to use the tried an true technique of putting the sub in your listening position then walking around the room listening for where the bass sounds the best....that IS the place you should put your sub, if possible.

For HT effects, corner loading may not be the 'worst' thing! But it'll really affects your 'music' in a negative way.

cnh

Mike LoManaco

cnh wrote: »

The idea of just turning the sub crossover to its max is just to play it safe....it has no effect...but just in case....if you leave it at its highest this will allow the AVR to send it what it wants! So don't worry about that, just do it and forget it.

Gotcha. So even though the "highest" setting on the knob is 160Hz, crank it to this point?

As for corner loading, as you may know, yes, room boundaries increase the subs db levels but at the expense of the quality of the bass...it's a trade off. More bass means less controlled bass.

The best way to find the ideal spot for you sub...is to use the tried an true technique of putting the sub in your listening position then walking around the room listening for where the bass sounds the best....that IS the place you should put your sub, if possible.

For HT effects, corner loading may not be the 'worst' thing! But it'll really affects your 'music' in a negative way.

cnh

Understood. I'll see where I can actually place it.

Thanks 'cn.

kuntasensei

cnh is steering you in the right direction. Turning the knob to 160 on the sub is just for peace of mind, since LFE will be limited to 120Hz in your Onkyo and bass redirected from the other channels will transition near the crossover points you set. You won't actually have any 160Hz bass come from the sub with any appreciable energy.

Also, from my own experience with the PSW350 (and subs in general) and floorstanding speakers, don't place either within at least 3" of the wall if you can help it. Aesthetically, people tend to shove them flush against the wall for the sake of appearance. Sonically, placing them too close to the wall (especially with drywall) can make the wall itself act like a passive radiator, muddying the sound and potentially causing audible vibrations (and in worst case scenarios can cause cancellation/phase issues). Even if you corner load the sub (which may not be an awful idea with the PSW350, depending on your room), keep it at least 3" away from either wall. The PSW350 is forward firing so you likely won't have issues... but keep in mind that if the port for the sub is firing toward the wall, you're basically throwing equal bass energy out behind it, directly at a reflective surface. Give it a little room.

cnh

kuntasensei wrote: »

cnh is steering you in the right direction. Turning the knob to 160 on the sub is just for peace of mind, since LFE will be limited to 120Hz in your Onkyo and bass redirected from the other channels will transition near the crossover points you set. You won't actually have any 160Hz bass come from the sub with any appreciable energy.

Also, from my own experience with the PSW350 (and subs in general) and floorstanding speakers, don't place either within at least 3" of the wall if you can help it. Aesthetically, people tend to shove them flush against the wall for the sake of appearance. Sonically, placing them too close to the wall (especially with drywall) can make the wall itself act like a passive radiator, muddying the sound and potentially causing audible vibrations (and in worst case scenarios can cause cancellation/phase issues). Even if you corner load the sub (which may not be an awful idea with the PSW350, depending on your room), keep it at least 3" away from either wall. The PSW350 is forward firing so you likely won't have issues... but keep in mind that if the port for the sub is firing toward the wall, you're basically throwing equal bass energy out behind it, directly at a reflective surface. Give it a little room.

Thanks Kuntasensei,

I just wanted to highlight your post so Mike could see it as well.

cnh