PSW505 Subwoofer bottoming out?

xxmastermushxx

Hello, I've owned my Polk Audio PSW505 since Christmas, and was curious if what I'm experiencing is bottoming out.

Here's my equipment:

• Polk Audio PSW505
• Denon AVR-590

When I play a movie that has more bass heavy scenes such as War Of The Worlds, the subwoofer makes a wu-wump sound. It doesn't make a clang or metal hitting metal sound, just wump, wu-wump, wump etc...

My subwoofer's out of any corners, it has something around two, three feet of space behind, and nothing crowding around. I've calibrated the room using Audyssey, I set the crossover frequency at max (even though I use LFE out) and the volume at 12 O'clock when calibrating. It's set the subwoofer at -6.0 DB, and says it's 9.5 or so feet away. I've tried putting the master volume at something like -37 DB but at that level it defeats the whole reason of having a "home theater" system.

PS: If it matters, I'm using no special monster cable subwoofer connector, or anything fancy in that matter.

Let me know what you think.

Ron Temple

Welcome to CP...

WOTW will bring many subs to their knees. There's a ton of subsonic content below 10hz and very loud content in the 20-30hz range. I'm sure Polk has some protection below 25hz built in to the 505s amp, but it's obviously struggling with the low content. Your only option is to turn things down to protect the sub. In order to play content like that you really need a bottom dweller sub with plenty of amp power. The 505 is a decent Polk product. Keep it within it's limits and you'll be fine.

dane_peterson

To add to Ron's post,
WOTW is quite possibly THE most demanding film ever made for a subwoofer playback. I used it with my Sonosubs back in the day and rattled the entire apartment building. It wouldn't be uncommon for your 505 to bottom out in that movie, or some select others. Do you only experience this in the VERY low scenes?

http://www.avsforum.com/avs-vb/showthread.php?t=755493

xxmastermushxx

I believe it to be in most VERY low scenes. I only gave the example of WOTW because it was a good example of LOW frequency.

I simply started this thready because I was curious of ways to minimize this "problem."

Another example of a movie that had this was Fight Club, at the very end scene explosives destroy a couple of buildings, I had the receivers master volume at -21.5 running in DTS-HD 5.1, and the subwoofer still made a wu-wumping sound within its deep rumble.

I suppose there's nothing much to do, it is only a 12" not an 18". I need to be less demanding.

Edit: There were some others scenes in WOTW where they were boarding the ferry and there was just some wu-wumping. I didn't here any bass, just wu-wump.

Ron Temple

Do you have a SPL meter? If not get one and calibrate the sub no more than 2 or 3dbs hotter than your mains. If you've let Audyssey do it, then back off the sub trim in Speaker setup a couple of dbs and see if that fixes the problem. If you did it by ear, then you are probably waaaaayyyy hot and asking the sub for more than it can give.

mystik610

xxmastermushxx wrote: »

I believe it to be in most VERY low scenes. I only gave the example of WOTW because it was a good example of LOW frequency.

I simply started this thready because I was curious of ways to minimize this "problem."

Another example of a movie that had this was Fight Club, at the very end scene explosives destroy a couple of buildings, I had the receivers master volume at -21.5 running in DTS-HD 5.1, and the subwoofer still made a wu-wumping sound within its deep rumble.

I suppose there's nothing much to do, it is only a 12" not an 18". I need to be less demanding.

Edit: There were some others scenes in WOTW where they were boarding the ferry and there was just some wu-wumping. I didn't here any bass, just wu-wump.

According to Polks website, the PSW505's frequency response is limited to 23hz on the bottom end, with the -3db roll-off point occurring at 28hz. The 505's output will start to wane at 28hz...below 23hz the 505 won't have any useful output.

A lot of modern movie sound-tracks (particularly lossless tracks) have LFE content that's digging below 20hz these days.....most subwoofers will struggle to play this material. The size of the driver comes into play, but isn't the sole factor determining how low your sub can dig. There are plenty of 12 inch subwoofers that dig down to 18hz and lower.

I had the same problem with my old sub, which rolled off at 30hz. Turning the subwoofer gain will help, but won't eliminate the problem...the sub will likely still struggle trying to play extremely low frequencies at low volumes. You might want to try adjusting the equalizer for the sub on your receiver....turn down the output anywhere below 25hz.

Another option is to find a high pass filter to keep those extremely low frequencies from playing from your sub altogether.

xxmastermushxx

I really don't actually believe it's the frequencies, I've been talking with my dad and he believes (which I strongly agree with too) that the speaker isn't having trouble PLAYING the really low frequencies, but is getting over driven.

I tried once playing the subwoofer with a 1:00 minute 20hz frequency, and the subwoofer didn't actually bottom out, it wasn't being told to produce the 20hz frequency at very LOUD levels. Which is the opposite when watching a movie such as WOTW.

Is there a way to limit the amount of power/wattage/voltage what ever it is fed to the subwoofer?

Thanks

xxmastermushxx

xxmastermushxx wrote: »

I really don't actually believe it's the frequencies, I've been talking with my dad and he believes (which I strongly agree with too) that the speaker isn't having trouble PLAYING the really low frequencies, but is getting over driven.

I tried once playing the subwoofer with a 1:00 minute 20hz frequency, and the subwoofer didn't actually bottom out, it wasn't being told to produce the 20hz frequency at very LOUD levels. Which is the opposite when watching a movie such as WOTW.

Is there a way to limit the amount of power/wattage/voltage what ever it is fed to the subwoofer?

Thanks

There doesn't seem to be a way to re-edit posts.

I just wanted to add that the amp on my PSW505 appears to be clipping, that seems to be the "problem." Just wanted to make it more clear, my other post was rather vague about it instead of just saying out right.

cnh

That is certainly possible, if I'm not mistaken that sub has a 460W dynamic peak..for short bursts....but trying to get a 12" woofer to put out a lot of DBs at less than 25hz requires A LOT of POWER...lots. That's what Ron is saying to you above. You're probably running the sub too hot. You should NOT always be able to hear a sub...if you can then you are overdriving it. Lots of people think that they have to turn their subs up till they distort. If the sub says it can't play below 28hz don't push it. In all likelihood it can't even reach 90db at 28hz? The lower limit spec rarely comes with a db figure? 28hz at how many Decibels of loudness??

Good Luck.

cnh

mystik610

xxmastermushxx wrote: »

I really don't actually believe it's the frequencies, I've been talking with my dad and he believes (which I strongly agree with too) that the speaker isn't having trouble PLAYING the really low frequencies, but is getting over driven.

I tried once playing the subwoofer with a 1:00 minute 20hz frequency, and the subwoofer didn't actually bottom out, it wasn't being told to produce the 20hz frequency at very LOUD levels. Which is the opposite when watching a movie such as WOTW.

Is there a way to limit the amount of power/wattage/voltage what ever it is fed to the subwoofer?

Thanks

I don't think you're clipping your amp....If you were clipping your amp and pushing the driver to its physical excursion limits, you'd here a pretty violent clap/pop...its far more violent than the 'wud-ump' you described.

It sounds like what you're hearing is distortion caused by caused by port-flow restriction/compression in the sub. With smaller ported subs, evidence of this will usually happen well before you start to clip your amp or push the woofer beyond its excursion limits.

Given the size of the 505, I can see why it would start to roll-off at 28hz....it has less to do with the size of the driver or how power the amp is, and more to do with the limited size of the enclosure and port. In order for a ported sub to output below 30hz with a respectable level of output, it will have to move A LOT of air. If the enclosure and ports aren't large enough, the subwoofer will start to compress and distort.

Your sub may be able to play down to 20hz at low volumes, but its inability to move enough air is likely causing distortion when reproducing those frequencies at the levels a movie sound-track would demand.

As mentioned earlier, there are plenty of ported 12 inch subs that can hit hard down to 18hz or lower, but the enclosures on these subs are huge in comparison to the 505.

xxmastermushxx

So if Audyssey is running my sub "hot" what can I do without effecting the not so deep/loud frequencies? If I turned the volume of the sub down in the receiver menu, the lower frequencies will improve, but that means the other frequencies that sub doesn't bottom out on will have less impact. Any ideas?

Thanks

mystik610

xxmastermushxx wrote: »

So if Audyssey is running my sub "hot" what can I do without effecting the not so deep/loud frequencies? If I turned the volume of the sub down in the receiver menu, the lower frequencies will improve, but that means the other frequencies that sub doesn't bottom out on will have less impact. Any ideas?

Thanks

I had the exact same problem with audyssey and my old sub. A lot of people have problems with audyssey calibrations and subs that are lacking below 30hz....there are entire threads dedicated to this issue. According to some, Audyssey will try to flatten the response of your sub by boosting the frequencies that start to roll-off. In my experience, it seems audyssey tries to compensate for the frequency roll-off by lowering the subs over-all output. This, like you mentioned, means that the upper and mid-bass frequencies will have less impact.

With my old sub, when I used the subwoofer gain audyssey set, I didn't have any distortion, but I didn't have much output in the LFE channel either. When I set the gain where my ears liked it, the sub would start to compress at the lower frequencies.

I eventually got rid of this problem by buying a better sub. If this isn't an option, look into this:

http://www.markertek.com/Audio-Equipment/Audio-Interface/Impedance-Matching-Transformer/Shure-Inc/A15AS.xhtml

This will filter the lower frequencies out of the signal line and keep them from playing through your sub.

xxmastermushxx

mystik610 wrote: »

I had the exact same problem with audyssey and my old sub. A lot of people have problems with audyssey calibrations and subs that are lacking below 30hz....there are entire threads dedicated to this issue. According to some, Audyssey will try to flatten the response of your sub by boosting the frequencies that start to roll-off. In my experience, it seems audyssey tries to compensate for the frequency roll-off by lowering the subs over-all output. This, like you mentioned, means that the upper and mid-bass frequencies will have less impact.

With my old sub, when I used the subwoofer gain audyssey set, I didn't have any distortion, but I didn't have much output in the LFE channel either. When I set the gain where my ears liked it, the sub would start to compress at the lower frequencies.

I eventually got rid of this problem by buying a better sub. If this isn't an option, look into this:

http://www.markertek.com/Audio-Equipment/Audio-Interface/Impedance-Matching-Transformer/Shure-Inc/A15AS.xhtml

This will filter the lower frequencies out of the signal line and keep them from playing through your sub.

So when you had this problem, at really low frequencies Audyssey for you didn't make the subwoofer compress, only when YOU modified it? In my case it always compresses when ever a REALLY deep/loud frequency plays.

I've seen those High Pass Filters, but how would that help? If I got a HPS it would cut me of at lets say, 23hz. Then any frequency below that wouldn't even play? My sub has played below 20hz though, just not at really LOUD levels. Please explain, I'm confused.

Thanks

Edit: Will the SHURE High Pass Filter automatically filter it out? Will it filter out the frequencies when the subwoofer starts to compress?

mystik610

xxmastermushxx wrote: »

So when you had this problem, at really low frequencies Audyssey for you didn't make the subwoofer compress, only when YOU modified it? In my case it always compresses when ever a REALLY deep/loud frequency plays.

In my case I would only hear compression after I turned the subwoofer gain up...the default audyssey settings didn't cause any distortion.

In your case, audyssey really might be boosting the lower frequencies to compensate for the roll-off at 28hz. Try playing the scenes that made your sub compress with audyssey off and see if the problem persists. If you find that audyssey really is causing the problem, turn it off and manually EQ the frequencies below 28hz....of course this means you'll lose the benefits of Audyssey dynamic EQ.

xxmastermushxx wrote: »

I've seen those High Pass Filters, but how would that help? If I got a HPS it would cut me of at lets say, 23hz. Then any frequency below that wouldn't even play? My sub has played below 20hz though, just not at really LOUD levels. Please explain, I'm confused.

Thanks

One thing that you have to consider is that you'll very rarely, if ever, hear subsonic frequencies (anything below 30hz) at anything other than loud volumes in a movie soundtrack...unless maybe you're listening to pipe organ music or test tones. Most subsonic material we hear in movies come from explosions, some sort of earth movement, etc etc.

To properly convey this material, a sub needs to be able to play loudly in the lower frequencies. If your sub can't hit those low frequencies hard, you're better off filtering or EQ'ing them out...the alternative is nasty sounding distortion.

xxmastermushxx wrote: »

Edit: Will the SHURE High Pass Filter automatically filter it out? Will it filter out the frequencies when the subwoofer starts to compress?

I'm looking at the link I posted and it doesn't look like that's exactly what you need. This is what you'll want to try:

http://store.hlabs.com/pk4/store.pl?view_product=10

These will apply a 12db drop in output starting at either 20hz or 30hz, depending on which one you opt for, which should mediate the distortion you're hearing. The FMOD will have no idea when your sub starts to compress...it merely mimics the functions of a cross-over or high pass filter.

xxmastermushxx

So any frequency below 20hz will just be filtered out? Isn't there a way of just doing that in the receiver? I have a Denon AVR-590.

I tried another scene, it was LOTR: Fellowship of the ring. The scene is 3:49, it's where the ring hits the ground, and is where a 8hz frequency is played. The subwoofer also went wu-wump here, and even after turning it down to -22 DB it went wu-wump, but was less audible.

You mentioned something about EQing the subwoofer. How how would I go around doing this?

Thanks for all your help

xxmastermushxx

xxmastermushxx wrote: »

So any frequency below 20hz will just be filtered out? Isn't there a way of just doing that in the receiver? I have a Denon AVR-590.

I tried another scene, it was LOTR: Fellowship of the ring. The scene is 3:49, it's where the ring hits the ground, and is where a 8hz frequency is played. The subwoofer also went wu-wump here, and even after turning it down to -22 DB it went wu-wump, but was less audible.

You mentioned something about EQing the subwoofer. How how would I go around doing this?

Thanks for all your help

Edit: I read on AVS Forum about how MultEQ creates distortion in sub-woofers. Apparently, if there's headroom, MultEQ will boost the subwoofer in lower frequencies. One guy used an SPL meter and found out that Audyssey boosted his subwoofer +12 DB at 10hz, causing the subwoofer to bottom out, sound familiar?

Here's the link: http://www.avsforum.com/avs-vb/showthread.php?t=1078077

The way he, or some other guy, solved the problem was by using a High Pass Filter, like you've said. I'm just curious, Would I really want to cut my subwoofer off at 20 hz? How would I know what frequency I should cut my subwoofer off at?

Thanks!

mystik610

xxmastermushxx wrote: »

So any frequency below 20hz will just be filtered out? Isn't there a way of just doing that in the receiver? I have a Denon AVR-590.

I tried another scene, it was LOTR: Fellowship of the ring. The scene is 3:49, it's where the ring hits the ground, and is where a 8hz frequency is played. The subwoofer also went wu-wump here, and even after turning it down to -22 DB it went wu-wump, but was less audible.

You mentioned something about EQing the subwoofer. How how would I go around doing this?

Thanks for all your help

The denon should have a low pass filter for the LFE channel, but not a high pass filter.

I'm not sure how it would work on the Denon, but in my Onkyo there's an equalizer menu that by default is set to 'Audyssey'. By setting it to manual, I'm able to adjust the EQ settings myself. Simply turning audyssey off might be enough , but you can adjust the trim at the lower frequencies if necessary.

xxmastermushxx wrote: »

Edit: I read on AVS Forum about how MultEQ creates distortion in sub-woofers. Apparently, if there's headroom, MultEQ will boost the subwoofer in lower frequencies. One guy used an SPL meter and found out that Audyssey boosted his subwoofer +12 DB at 10hz, causing the subwoofer to bottom out, sound familiar?

Here's the link: http://www.avsforum.com/avs-vb/showthread.php?t=1078077

The way he, or some other guy, solved the problem was by using a High Pass Filter, like you've said. I'm just curious, Would I really want to cut my subwoofer off at 20 hz? How would I know what frequency I should cut my subwoofer off at?

Thanks!

I think the problem is, Audyssey has no idea of knowing if your sub has enough headroom to play the subsonic frequencies at listening levels...let alone reference or peak levels. The audyssey test tones for the main speakers are pretty damn loud.....the test tones for the subwoofer are comparably soft. It doesn't seem that audyssey is designed to account for the limitations of a subwoofer. Tts sole purpose is to flatten the response of your sub. It has no idea that the drop in frequency response at 28hz is a limitation of the sub itself. It will equate this drop off to room response, and boost the frequencies to compensate.

But given that audyssey is designed to give a flat frequency response across all your channels and account for the acoustic properties of your room...one thing you should realize is that the real reason you're having these problems is that your sub doesn't have enough output for your room. The LFE settings for audyssey are rather conservative. Audyssey will set the lfe channel at a level where your sub will be level matched to your mains. Most people prefer to run their LFE channels a few DB's higher than their mains. How big is your room?

mystik610

xxmastermushxx wrote: »

I'm just curious, Would I really want to cut my subwoofer off at 20 hz? How would I know what frequency I should cut my subwoofer off at?

Thanks!

Your best bet is to pick up an SPL meter from Radio shack and download some test tones to play through your system. Place the SPL meter on a tripod or something similar and take note of the changes in SPL (sound pressure level) at different frequencies. You should filter out the frequencies where you start to see a drastic drop in SPL. Based on Polk's specs, you'll probably see the SPL slope downwards at around 30hz, and fall off sharply at around 25hz....that's a pretty small window actually.

I'm thinking you might actually want to use a 30hz high pass filter....which sounds less than ideal, but will sound fine 95% of the time. It will certainly sound better than hearing distorion.

xxmastermushxx

How big is your room?

The room I have is 19X18 with a nine foot ceiling.

Here's some pictures of my room: Attachment not found.

mystik610 wrote: »

Your best bet is to pick up an SPL meter from Radio shack and download some test tones to play through your system. Place the SPL meter on a tripod or something similar and take note of the changes in SPL (sound pressure level) at different frequencies. You should filter out the frequencies where you start to see a drastic drop in SPL. Based on Polk's specs, you'll probably see the SPL slope downwards at around 30hz, and fall off sharply at around 25hz....that's a pretty small window actually.

I'm thinking you might actually want to use a 30hz high pass filter....which sounds less than ideal, but will sound fine 95% of the time. It will certainly sound better than hearing distorion.

Yeah, I figured a 30hz high pass filter would probably be the best solution; however, I thought at anything below 20hz just got cut off using a 20hz high pass filter. At 19hz wouldn't that be at -12db? Or do they go down -3db an octave?

I believe this subwoofer can do well at 20hz, I played the same 20hz tone again, and really boosted the sound up, no wu-wump. I was going to try a movie with good strong 20hz in it and see if it wu-wumps. If I can, I'd prefer a 20hz filter over a 30hz, but will see.

Thanks

mystik610

xxmastermushxx wrote: »

The room I have is 19X18 with a nine foot ceiling.

Here's some pictures of my room: Attachment not found.



Yeah, I figured a 30hz high pass filter would probably be the best solution; however, I thought at anything below 20hz just got cut off using a 20hz high pass filter. At 19hz wouldn't that be at -12db? Or do they go down -3db an octave?

From the marketing material, it looks like it will apply -12db filter per octave...it doesn't sound like you'll be at -12db until a full octave lower. That being said, it looks like you can put two FMODs on yours subwoofer line and it will apply a -24db filter per octave. I'd start with a 20hz high pass filter, and if the problem persists, return it for the 30hz one.

xxmastermushxx wrote: »

I believe this subwoofer can do well at 20hz, I played the same 20hz tone again, and really boosted the sound up, no wu-wump. I was going to try a movie with good strong 20hz in it and see if it wu-wumps. If I can, I'd prefer a 20hz filter over a 30hz, but will see.

Thanks

Your sub might be able to handle test tones...but is probably having trouble playing spikes of high SPL low frequencies you typically find in movie soundtracks. I'm talking 100DB spikes or higher at 20hz or lower....which in a movie like LOTR, isn't totally unreasonable at a moderate-high listening level.

You can probably tell from the test tones, that 20hz at a low SPL is pretty unremarkable, and nothing to comment about. At high SPL's, 20hz will compress the room, shake walls, and rattle your bones....this is what most of us look for with subsonic frequencies, and this is the level at which they're usually edited into a movies soundtrack.

xxmastermushxx

You can probably tell from the test tones, that 20hz at a low SPL is pretty unremarkable, and nothing to comment about. At high SPL's, 20hz will compress the room, shake walls, and rattle your bones....this is what most of us look for with subsonic frequencies, and this is the level at which they're usually edited into a movies soundtrack.

Yeah, I've noticed that.

I guess I'll try a 20hz High Pass Filter, see if that works. I'm still looking for a movie that can play a 20 hz frequency at, like you said, 100Db spike. Do you know any scenes in LOTR that have frequencies like that, I looked in the AVS Forum's list of BASS movies and couldn't find any 20hz 100db spikes in LOTR.

I tried a new test tone, this tone went from 100hz-5hz, it was pretty damn impressive. The PSW505 played down to 5hz even though I had to really turn the volume up to make anything out of it. I could see why a movie like WOTW would bottom out this sub.

Ron Temple

xxmastermushxx wrote: »

I tried a new test tone, this tone went from 100hz-5hz, it was pretty damn impressive. The PSW505 played down to 5hz even though I had to really turn the volume up to make anything out of it. I could see why a movie like WOTW would bottom out this sub.

What you're hearing is distortion harmonics and room resonance. 18hz at 100dbs is about the lowest the human ear can hear. The distorion harmonics are probably 40hz and 80hz. Really with that sub you should be dead silent or very low below 25hz. Since it's not something else is being excited. I wouldn't even try to listen to tones above the 75db level for testing. You can damage the amp and driver through clipping trying to get audible performance in the deep stuff.

mystik610

xxmastermushxx wrote: »

Yeah, I've noticed that.

I guess I'll try a 20hz High Pass Filter, see if that works. I'm still looking for a movie that can play a 20 hz frequency at, like you said, 100Db spike. Do you know any scenes in LOTR that have frequencies like that, I looked in the AVS Forum's list of BASS movies and couldn't find any 20hz 100db spikes in LOTR.

Check out this list of 'demo' scenes from SVS's website. A few 'demo' scenes from LOTR are listed there....including the ring dropping scene that you mentioned made your sub compress.

http://www.svsound.com/questions-faqs.cfm#moviedemos

The Balrog scene near the end of the fellowship of the ring is one of my favorites.

Iron Man is a staple 'demo' movie for me....the entire scene in the cave, and the scene with the F-22's will give your sub a workout.

Another good demo clip....look for the 'Amazing Life' THX demo. Burn it on a DVD or play it via a network player. Watch out for the 'mushroom drums of death'

xxmastermushxx

Check out this list of 'demo' scenes from SVS's website. A few 'demo' scenes from LOTR are listed there....including the ring dropping scene that you mentioned made your sub compress.

http://www.svsound.com/questions-faqs.cfm#moviedemos

The Balrog scene near the end of the fellowship of the ring is one of my favorites.

Iron Man is a staple 'demo' movie for me....the entire scene in the cave, and the scene with the F-22's will give your sub a workout.

Another good demo clip....look for the 'Amazing Life' THX demo. Burn it on a DVD or play it via a network player. Watch out for the 'mushroom drums of death'

Are these just recommended movies to watch? I can't get any actual movie demos, or short clips of movies. Am I missing something?

What you're hearing is distortion harmonics and room resonance. 18hz at 100dbs is about the lowest the human ear can hear. The distorion harmonics are probably 40hz and 80hz. Really with that sub you should be dead silent or very low below 25hz. Since it's not something else is being excited. I wouldn't even try to listen to tones above the 75db level for testing. You can damage the amp and driver through clipping trying to get audible performance in the deep stuff.

Yeah, it started to distort around 20-15hz. I'll take your advice and stay clear of attempting to get an audible response from a 5 Hz frequency.

TECHNOKID

mystik610 wrote: »

I don't think you're clipping your amp....If you were clipping your amp and pushing the driver to its physical excursion limits, you'd here a pretty violent clap/pop...its far more violent than the 'wud-ump' you described.

It sounds like what you're hearing is distortion caused by caused by port-flow restriction/compression in the sub. With smaller ported subs, evidence of this will usually happen well before you start to clip your amp or push the woofer beyond its excursion limits.

Given the size of the 505, I can see why it would start to roll-off at 28hz....it has less to do with the size of the driver or how power the amp is, and more to do with the limited size of the enclosure and port. In order for a ported sub to output below 30hz with a respectable level of output, it will have to move A LOT of air. If the enclosure and ports aren't large enough, the subwoofer will start to compress and distort.

Your sub may be able to play down to 20hz at low volumes, but its inability to move enough air is likely causing distortion when reproducing those frequencies at the levels a movie sound-track would demand.

As mentioned earlier, there are plenty of ported 12 inch subs that can hit hard down to 18hz or lower, but the enclosures on these subs are huge in comparison to the 505.

Ron Temple wrote: »

What you're hearing is distortion harmonics and room resonance. 18hz at 100dbs is about the lowest the human ear can hear. The distorion harmonics are probably 40hz and 80hz. Really with that sub you should be dead silent or very low below 25hz. Since it's not something else is being excited. I wouldn't even try to listen to tones above the 75db level for testing. You can damage the amp and driver through clipping trying to get audible performance in the deep stuff.

+1, the OP is simply pushing the sub above its abilities.

WEAKNESSES:
On low frequencies the port has a flutter noise from the air but its only on the really low stuff Like 25 herts so its no big deal.WEAKNESSES:
It would be nice to be able to go down to 30hz on the crossover -- but for the price I am NOT complaining!

WEAKNESSES:
It would be nice to be able to go down to 30hz on the crossover -- but for the price I am NOT complaining!

Yet out of 59 reviews, only 2 mentions the weakness at lower frequencies (at or below 25 hz which you are trying to aim at even lower (20 hz) and furthermore at high db rate. This subwoofer does what Polk claims it can do). At the blasting level you seem to be trying to drive it along with lower range that it can perform, this is the only reason you are having this issue, your options would be to either get a subwoofer which has the ability to go lower in the low range or maybe buy a second PSW505 which should allow you to run them at lower level gain which would give a break to the subwoofers when trying to get them to perform in the area of 20 - 25 hz and still provide you with the blasting level your looking for, now, the only problem that would be left is damaging your hearing

xxmastermushxx

TECHNOKID wrote: »

+1, the OP is simply pushing the sub above its abilities.

Yet out of 59 reviews, only 2 mentions the weakness at lower frequencies (at or below 25 hz which you are trying to aim at even lower (20 hz) and furthermore at high db rate. This subwoofer does what Polk claims it can do). At the blasting level you seem to be trying to drive it along with lower range that it can perform, this is the only reason you are having this issue, your options would be to either get a subwoofer which has the ability to go lower in the low range or maybe buy a second PSW505 which should allow you to run them at lower level gain which would give a break to the subwoofers when trying to get them to perform in the area of 20 - 25 hz and still provide you with the blasting level your looking for, now, the only problem that would be left is damaging your hearing

Please don't take me wrong, if your judging me off of my comment about the 100Hz-5hz test tone, and believing I'm over driving my sub, don't. I just tried that test tone to see what this sub can do, and was pleasantly surprised to see the thing actually move air.

I'm trying to solve my problem of distortion, and I believe to have found the solution.

I use Audyssey, and leave it to Audyssey to set my sub, I strive for perfection, and if you met me in person, I'd probably drive you nuts (I know it drives my dad nuts). Mind you, I'm only fifteen, I don't have any high paying job, I can't even get a job for another year.

If I could, I'd love to get a Velodyne sub that can pump 14Hz frequencies.

I'm not trying to push my sub, I'm trying to solve the problem of Audyssey pushing my sub. If I can get away with a strong 20hz frequency from distorting, I'll be happy, if not, I guess I'll have to do with a 30hz filter.

TECHNOKID

xxmastermushxx wrote: »

Please don't take me wrong, if your judging me off of my comment about the 100Hz-5hz test tone, and believing I'm over driving my sub, don't. I just tried that test tone to see what this sub can do, and was pleasantly surprised to see the thing actually move air.

I'm trying to solve my problem of distortion, and I believe to have found the solution.

I use Audyssey, and leave it to Audyssey to set my sub, I strive for perfection, and if you met me in person, I'd probably drive you nuts (I know it drives my dad nuts). Mind you, I'm only fifteen, I don't have any high paying job, I can't even get a job for another year.

If I could, I'd love to get a Velodyne sub that can pump 14Hz frequencies.

I'm not trying to push my sub, I'm trying to solve the problem of Audyssey pushing my sub. If I can get away with a strong 20hz frequency from distorting, I'll be happy, if not, I guess I'll have to do with a 30hz filter.

No judgment here, if you think that was the purpose of my thread I apologize.

I find odd that Audissey doesn't set the sub appropriately. I have a PSW110 which is not as good as the PSW505 and never had any problem as the YAPO sets it appropriately and it follows the speakers settings as I increase the volume no problem. I don't believe it is a power issue since you have mentioned you do not drive the sub at more than half power however trying to go below its average specs seems to cause the problem. Subwoofers are the most demanding speakers and especially at the lower end. If Audissey will not properly set the subwoofer for its optimum, have you tried manually setting it up? Doing such might help you find the best setting for your specific listening in your specific room. Yet experimenting might be your best way to optimize and will also get you to know your sub capability and limitations. Some that I agreed with Ron and wanted to emphasize is the below:

Really with that sub you should be dead silent or very low below 25hz. Since it's not something else is being excited. I wouldn't even try to listen to tones above the 75db level for testing. You can damage the amp and driver through clipping trying to get audible performance in the deep stuff

I use Avia II for test tones and in their WARNING section, they specifically point out that;

Your audio system should be set to normal listening level before using the audio test tones

...and the main reasons are to not damage either your speakers and your hearing.

Note that I ended my post with smilies Keep us posted

Cheers!
TK

BeefJerky

I also wonder why Audyssey is setting your sub up that way. I've used Audyssey MultiEQ on my Denon AVR-788, and even with a bottom-of-the-line Velodyne VX-10 (36hz at -3db, and lucky to hit 30hz at all) I've never run into that issue. I've also used a Polk PSW650 and (my current sub) a Paradigm PW2500 in this setup without issue.

xxmastermushxx

Thanks for the support, I calibrate my setup quite profusely until I'm happy with the stats. Audyssey always seems to drive the subwoofer "hot" at lower frequencies.

I've talked to my dad and said I could get a FMOD 20Hz High Pass Filter for $30. His reply was "those aren't worth fifty cents, I can make them for cheaper." So, we're going to make are own, since he is an electrical engineer, and has done these things before. We're going to create one that filters out after 25Hz, that should keep the lower ends from distorting but leave us with DEEP bass.

mystik610

TECHNOKID wrote: »

I find odd that Audissey doesn't set the sub appropriately. I have a PSW110 which is not as good as the PSW505 and never had any problem as the YAPO sets it appropriately and it follows the speakers settings as I increase the volume no problem. I don't believe it is a power issue since you have mentioned you do not drive the sub at more than half power however trying to go below its average specs seems to cause the problem. Subwoofers are the most demanding speakers and especially at the lower end. If Audissey will not properly set the subwoofer for its optimum, have you tried manually setting it up? Doing such might help you find the best setting for your specific listening in your specific room. Yet experimenting might be your best way to optimize and will also get you to know your sub capability and limitations. Some that I agreed with Ron and wanted to emphasize is the below:

BeefJerky wrote: »

I also wonder why Audyssey is setting your sub up that way. I've used Audyssey MultiEQ on my Denon AVR-788, and even with a bottom-of-the-line Velodyne VX-10 (36hz at -3db, and lucky to hit 30hz at all) I've never run into that issue. I've also used a Polk PSW650 and (my current sub) a Paradigm PW2500 in this setup without issue.

Room response probably has a lot to do with it....if the subwoofer and/or listening area are sitting in a null area in the room, the roll-off at the subsonic frequencies will be further accentuated, as the lower frequencies are more susceptible to standing waves.

This is accentuated even further if the subwoofer is too small for a room, and the mains are actually overpowering the sub. At the end of the day, I think that's the OP's problem...given his listening levels, the sub simply isn't powerful enough. One of audyssey's main goals is to level match the subwoofer with the main speakers...if there's any kind of distortion with audyssey's default settings, then the sub flat out can't keep up with the mains given the size of the room. If the sub is running a little hot trying to play the mid/upper bass frequencies, it will run very hot trying to play the lower frequencies...couple that with some boosting of the lower frequencies by audyssey, and you can see why he's having problems.

tonyb

Did I miss where the OP stated his front speakers ? Is he trying to run the sub with the TV speakers ? I would imagine his problems are a combination of things. Whats the crossover in the AVR set at ? Pushing too hard...could be. Placement...maybe, but I tend to lean more towards a setup issue and the OP expecting too much from the sub in a room that size.