Bass trapping below 80hz, practical or not?

[yepimonfire]

I included the left speaker by itself to illustrate the steep drop off below 40hz on the front left side of the room near the closet. I get the same problem if I place a sub there.

I’m assuming the reason the surrounds and center don’t suffer as much of a peak is because they would normally roll off anechoic at about 63hz.

 

[yepimonfire]

Okay, I pulled the sub out and sat it in the mlp and measured around the room. Turns out, I found a relatively flat spot, but there’s a massive loss of content below 40hz. This seemed to be the case no matter where in the room I took measurements, leading me to believe it has to do with the listening position, not the sub placement. Lugging a big sub to different areas wasn’t practical, so I guess at this point I will just have to put the sub there and hope I can find a better measuring seating area.



Any idea what could be causing the loss below 40hz? This is sitting center left of the midpoint of the back wall. The phase response doesn’t suggest a room null spot, and neither does the group delay.

It almost looks similar to the bass leakage effect one sees sitting/placing a sub or speaker near an opening to another room. The dip is down almost 48 dB/octave

 

[TheWarrior]

I'm going 100 mph right now building a murphy bed from scratch, and painting, and packing for a trip, and...

Square rooms, or near square rooms have modes that stack on top of each other, and just like a filter, roll off at a certain slope so in your case, you don't have two peaks, rather a massive, high Q resonance as seen in 'sub only' and 'LR combined'.

I failed to mention earlier in my response to highfigh that the advice to measure all the speakers separately is great for speaker placement, but not for bass where you have to treat the system as a whole. If there's a pressure source not playing, then the distribution of modes in the room is going to be different.

I would measure again, with everything playing.

I cannot tell from your descriptions where anything is located, or where the mic was when measuring. Please take even an iPhone pic of sketch, whatever is easiest, to draw a diagram of the room. There's a closet? Draw that too! You're not having problems with it shaking/vibrating are you? Everything matters!

 

[TLS Guy]

I think Warrior makes a good point in his last post. You should consider getting rid of subs in a small room like that.

I came down to Eagan today. My wife is watching a movie on the main rig here.

I'm in a small room, that was a small bedroom but that we converted to a game room for the grandchildren.

I have just listened to the first half of the Friday evening concert of the Minnesota Orchestra live on this rig.

I'm just using two full range drivers with 4" aluminum cones weight 6 GM each. These drivers reach into the 40 Hz range.

The concert is very enjoyable and in this small room with plenty of bass gain the sound is full bodied and in no way anemic. We are talking a speaker design here nearly 60 years old. The sound is beautifully balanced.

I have thought of adding a couple of subs. However, I'm pretty sure I would create problems I don't now have. I never feel I need more bass listening to these speakers in this small room.

I listen to "Pipe Dreams" on occasions in this space, and I'm always astonished by the authority and clarity this rig brings to pipe organs even.

I personally still remain skeptical as to the benefits if discrete subs. Only one of my four rigs has discrete subs. One has integrated subs in the same enclosure, which I personally regard as integrated three way biamped speakers.

In my system that does have two discrete subs, the power drive to them is very low and the two 100 watts amps never get more than very slightly warm. Bass is not lacking and I don't get resonant problems.

I'm not at all convinced of the wisdom of this sub craze. I personally think it has created more problems than it has solved. I do think it has caused a deterioration in speakers on offer, especially in the lower octaves.

 

[yepimonfire]

I'm going 100 mph right now building a murphy bed from scratch, and painting, and packing for a trip, and...

Square rooms, or near square rooms have modes that stack on top of each other, and just like a filter, roll off at a certain slope so in your case, you don't have two peaks, rather a massive, high Q resonance as seen in 'sub only' and 'LR combined'.

I failed to mention earlier in my response to highfigh that the advice to measure all the speakers separately is great for speaker placement, but not for bass where you have to treat the system as a whole. If there's a pressure source not playing, then the distribution of modes in the room is going to be different.

I would measure again, with everything playing.

I cannot tell from your descriptions where anything is located, or where the mic was when measuring. Please take even an iPhone pic of sketch, whatever is easiest, to draw a diagram of the room. There's a closet? Draw that too! You're not having problems with it shaking/vibrating are you? Everything matters!

You mean all channels going at once?

I think you do have a point. With Audyssey enabled, if i measure the sub by itself, it starts rolling off at 30hz and is down almost 7dB at 23hz, if I measure the mains crossed to the sub @40hz, the combined response is pretty much flat to 22hz.

Considering the rp-160m is easily able to reproduce full range content down to 32hz without distortion in my room, I’m wondering if it might be beneficial to set them full range and utilize the lfe+main setting in the avr with a 60-80hz xover. As of right now, the combined response with an 80hz xover vs 40hz is worse.

 

[highfigh]

That's a lot to unpack but while I agree that the water tank is not an accurate comparison to sound reproduction in rooms and that flat is not the goal, inducing a gap into the system playback with subs rolled off at 60 hz and speakers playing at 80 hz is not a solution that favors accurate sound reproduction.

You have to look at this as it would be taught in physics! Yep has taken measurements with the subs rolled off at 40 hz and was able to reduce SPL by 5 dB @ 50 hz by sitting between the subwoofers placed in corners to the Left and Right with the front speakers providing most of (not all) amplitude for the 50 hz modal frequency.

12' = 47 hz
11' = 51 hz
8' = 70 hz

If Yep was sitting nearer the middle of the room, they could use the front speakers down to their natural roll off if desired, but because the LP is near the back wall, only the correct placement of subwoofers can control those peaks. Or just cut off all playback to 80 hz, lose the subs and 'fahget abott it!'

The gap is intentional- the result is what's important. Ever do competition car audio? The worst part of a car's road noise is in the 60Hz-250Hz range and in order for the system to sound remotely smooth or flattish, the EQ must remove a lot of sound, but the road noise makes up for it. The problem in a car is that the road noise may be >30dB higher than the average SPL from the system and that would require 1000x the power in the problem range for the system to overcome the noise, so the most common solution is to use sound deadening materials.

In a house, it's not likely to work, but having said that, I would fire up the pink noise and RTA, then go around the room placing my hand on the walls in different spots, to find the areas that resonate the most at those frequencies. Deaden those and I would bet the problem goes away. It's easier to use a frequency generator and slowly change the frequency until the problems rear their ugly heads. It could be a hanging picture, a window, door, wall panel....

Lose the sub and set the HP to 80Hz, and then you that say creating a gap will sound unnatural?

His seat is a foot from the rear wall- I would move it TO the wall- that's where mine is and the response is very smooth, but I dumped my sub when I built my speakers.

 

[highfigh]

I have thought of adding a couple of subs. However, I'm pretty sure I would create problems I don't now have. I never feel I need more bass listening to these speakers in this small room.

I listen to "Pipe Dreams" on occasions in this space, and I'm always astonished by the authority and clarity this rig brings to pipe organs even.

I personally still remain skeptical as to the benefits if discrete subs. Only one of my four rigs has discrete subs. One has integrated subs in the same enclosure, which I personally regard as integrated three way biamped speakers.

In my system that does have two discrete subs, the power drive to them is very low and the two 100 watts amps never get more than very slightly warm. Bass is not lacking and I don't get resonant problems.

I'm not at all convinced of the wisdom of this sub craze. I personally think it has created more problems than it has solved. I do think it has caused a deterioration in speakers on offer, especially in the lower octaves.

I would much rather have great mid-bass than bad bass/sub-bass. It's much less aggravating and less thought goes into listening to music without a sub. If it can be done right, great, but otherwise, I agree that it's not worth having if it will just cause problems.

 

[yepimonfire]

I think Warrior makes a good point in his last post. You should consider getting rid of subs in a small room like that.

I came down to Eagan today. My wife is watching a movie on the main rig here.

I'm in a small room, that was a small bedroom but that we converted to a game room for the grandchildren.

I have just listened to the first half of the Friday evening concert of the Minnesota Orchestra live on this rig.

I'm just using two full range drivers with 4" aluminum cones weight 6 GM each. These drivers reach into the 40 Hz range.

The concert is very enjoyable and in this small room with plenty of bass gain the sound is full bodied and in no way anemic. We are talking a speaker design here nearly 60 years old. The sound is beautifully balanced.

I have thought of adding a couple of subs. However, I'm pretty sure I would create problems I don't now have. I never feel I need more bass listening to these speakers in this small room.

I listen to "Pipe Dreams" on occasions in this space, and I'm always astonished by the authority and clarity this rig brings to pipe organs even.

I personally still remain skeptical as to the benefits if discrete subs. Only one of my four rigs has discrete subs. One has integrated subs in the same enclosure, which I personally regard as integrated three way biamped speakers.

In my system that does have two discrete subs, the power drive to them is very low and the two 100 watts amps never get more than very slightly warm. Bass is not lacking and I don't get resonant problems.

I'm not at all convinced of the wisdom of this sub craze. I personally think it has created more problems than it has solved. I do think it has caused a deterioration in speakers on offer, especially in the lower octaves.

If the system was used for music I’d just eq the front two speakers and forget about the sub, for whatever reason, fixing the LF response on the mains is quite easy vs the sub, a peak filter with a q of 1.5 -9dB @53hz and another filter with a q of 2 -3dB @48hz provided a perfectly flat response down to 32hz with significant reductions in ringing in the time domain as seen in the waterfall graph.

The issue that arises with home theater and why a sub is absolutely necessary is the LFE channel. You really need a response down to a minimum of 25-30hz, and it needs to be able to handle it with 10dB of headroom. Even if you don’t listen at reference volumes, let’s say you listen at -5dB, the sub has to be capable of 110dB at the main seating area, -15dB still requires an output of 100dB. Even if I were to upgrade to the massive RF-7III with dual 10” drivers, there is no way they would be capable of handling 115dB or even 110dB peaks down to 20hz.

When you add in bass management for 7 channels, the requirement goes up to about 118dB.

Even if your main speakers are 3 ways with a 15” woofer, I’m willing to bet that 15” woofer isn’t capable of reference level lfe playback. Subwoofers are designed strictly for content 20-120hz. Many subs break up and roll off above 120hz, because the drivers are intentionally designed to have a low fs. In addition, you often trade sensitivity for extension. A 15” woofer in a regular speaker may be required to play anywhere from 250hz-500hz cleanly.

Sub bass frequencies are mechanically the most difficult to reproduce, because the impedance match to air at extremely long wavelengths is awful, even with an 18” driver.

 

[yepimonfire]

I think Warrior makes a good point in his last post. You should consider getting rid of subs in a small room like that.

I came down to Eagan today. My wife is watching a movie on the main rig here.

I'm in a small room, that was a small bedroom but that we converted to a game room for the grandchildren.

I have just listened to the first half of the Friday evening concert of the Minnesota Orchestra live on this rig.

I'm just using two full range drivers with 4" aluminum cones weight 6 GM each. These drivers reach into the 40 Hz range.

The concert is very enjoyable and in this small room with plenty of bass gain the sound is full bodied and in no way anemic. We are talking a speaker design here nearly 60 years old. The sound is beautifully balanced.

I have thought of adding a couple of subs. However, I'm pretty sure I would create problems I don't now have. I never feel I need more bass listening to these speakers in this small room.

I listen to "Pipe Dreams" on occasions in this space, and I'm always astonished by the authority and clarity this rig brings to pipe organs even.

I personally still remain skeptical as to the benefits if discrete subs. Only one of my four rigs has discrete subs. One has integrated subs in the same enclosure, which I personally regard as integrated three way biamped speakers.

In my system that does have two discrete subs, the power drive to them is very low and the two 100 watts amps never get more than very slightly warm. Bass is not lacking and I don't get resonant problems.

I'm not at all convinced of the wisdom of this sub craze. I personally think it has created more problems than it has solved. I do think it has caused a deterioration in speakers on offer, especially in the lower octaves.

I don’t recall him saying I should get rid of the sub.

No, I don’t need a sub for music since I get about 35hz in room, Audyssey does a good job taming the peaks of the front speakers, but this system sees more movies than music.

 

[TLS Guy]

If the system was used for music I’d just eq the front two speakers and forget about the sub, for whatever reason, fixing the LF response on the mains is quite easy vs the sub, a peak filter with a q of 1.5 -9dB @53hz and another filter with a q of 2 -3dB @48hz provided a perfectly flat response down to 32hz with significant reductions in ringing in the time domain as seen in the waterfall graph.

The issue that arises with home theater and why a sub is absolutely necessary is the LFE channel. You really need a response down to a minimum of 25-30hz, and it needs to be able to handle it with 10dB of headroom. Even if you don’t listen at reference volumes, let’s say you listen at -5dB, the sub has to be capable of 110dB at the main seating area, -15dB still requires an output of 100dB. Even if I were to upgrade to the massive RF-7III with dual 10” drivers, there is no way they would be capable of handling 115dB or even 110dB peaks down to 20hz.

When you add in bass management for 7 channels, the requirement goes up to about 118dB.

Even if your main speakers are 3 ways with a 15” woofer, I’m willing to bet that 15” woofer isn’t capable of reference level lfe playback. Subwoofers are designed strictly for content 20-120hz. Many subs break up and roll off above 120hz, because the drivers are intentionally designed to have a low fs. In addition, you often trade sensitivity for extension. A 15” woofer in a regular speaker may be required to play anywhere from 250hz-500hz cleanly.

Sub bass frequencies are mechanically the most difficult to reproduce, because the impedance match to air at extremely long wavelengths is awful, even with an 18” driver.

I don't understand all this need for this kind of power. I use four 10" drivers, which is 2 per side. That is equivalent to ine 15 inch driver per side. All I know is that on movie scenes it shakes the whole room. The whole room gets ready to explode, and I think would if you were crazy with the volume control.

The rig easily puts you right in the battle field in War Horse for instance. The system does it effortlessly without breaking a sweat.

Mind you I'm using pipes which couple to the room extremely well. I have a feeling there need to be TL subs about, which are a rarity, but if what you say is required they should not be. As any organ builder will tell you pipes couple to the space in a unique way. An electric organ with speakers is much louder close to the speakers and spl falls rapidly with distance. A pipe organ however fills the space uniformly and the volume is not much less close or far from the organ. Organ builders call this phenomenon encircling. I suspect that is the reason the bass is so uniform throughout my room.

 

[yepimonfire]

I don't understand all this need for this kind of power. I use four 10" drivers, which is 2 per side. That is equivalent to ine 15 inch driver per side. All I know is that on movie scenes it shakes the whole room. The whole room gets ready to explode, and I think would if you were crazy with the volume control.

The rig easily puts you right in the battle field in War Horse for instance. The system does it effortlessly without breaking a sweat.

Mind you I'm using pipes which couple to the room extremely well. I have a feeling there need to be TL subs about, which are a rarity, but if what you say is required they should not be. As any organ builder will tell you pipes couple to the space in a unique way. An electric organ with speakers is much louder close to the speakers and spl falls rapidly with distance. A pipe organ however fills the space uniformly and the volume is not much less close or far from the organ. Organ builders call this phenomenon encircling. I suspect that is the reason the bass is so uniform throughout my room.

True, with you’re monster TL speakers there’s no need for a sub. I also forgot that the lfe is split between the two front channels, so in reality full reference level playback would only need 112dB per speaker. If placed near corners and the room gain eqed out to flat, you’d get even more headroom.

In my room larger 20x12 living room, with the RP-160m’s, I can get a clean output of about 107dB per channel from 32hz-80hz. Combined that’d be about 110dB, enough for -5dB from Reference. Still going to miss half an octave though without the sub. Xmax concerns don’t apply from about 45hz to 32hz with the speakers, since the port tuning is around this range.

I do agree that it’s easier to get good sounding bass from speakers vs trying to integrate a sub with an xover, but speakers capable of achieving sub 30hz output are far and few between. Not only that, but they are generally very expensive. TL speakers are extremely complicated enclosures to both build and design, even though they’re probably the best performing when it comes to excellent bass response, output, and extension.

I suppose I could give a subless system a shot, crossing the center and surrounds at 60hz to the fronts, and use eq on the front L/R speakers to tame that 53hz peak and reduce ringing in the time domain. At this point it’s not like I’m able to get a decent response below 40hz from the subwoofer anyways. Most of the exciting chest slamming, room shaking bass in the LFE channel falls in the 30-70hz range anyways, and given the size of the room, I should have no problems getting enough clean output.

I took a few measurements yesterday afternoon of the speakers only and the Audyssey corrected bass response from the l/r is fairly consistent from 30hz-200hz across the entire back half of the room, considering nobody sits on the front half, this might work out better. I’ll run some cea 2010 bursts later today and check the headroom, if I can get enough spl (112dB by my calculations) with just the fronts from 30hz on up without distortion, there’d be no reason to use a sub in the bedroom setup. Audyssey automatically filters out content below the measured f3, so there shouldn’t be any issues with frequencies below the box tuning causing unloading.

 

[TheWarrior]

True, with you’re monster TL speakers there’s no need for a sub. I also forgot that the lfe is split between the two front channels, so in reality full reference level playback would only need 112dB per speaker. If placed near corners and the room gain eqed out to flat, you’d get even more headroom.

In my room larger 20x12 living room, with the RP-160m’s, I can get a clean output of about 107dB per channel from 32hz-80hz. Combined that’d be about 110dB, enough for -5dB from Reference. Still going to miss half an octave though without the sub. Xmax concerns don’t apply from about 45hz to 32hz with the speakers, since the port tuning is around this range.

I do agree that it’s easier to get good sounding bass from speakers vs trying to integrate a sub with an xover, but speakers capable of achieving sub 30hz output are far and few between. Not only that, but they are generally very expensive. TL speakers are extremely complicated enclosures to both build and design, even though they’re probably the best performing when it comes to excellent bass response, output, and extension.

I suppose I could give a subless system a shot, crossing the center and surrounds at 60hz to the fronts, and use eq on the front L/R speakers to tame that 53hz peak and reduce ringing in the time domain. At this point it’s not like I’m able to get a decent response below 40hz from the subwoofer anyways. Most of the exciting chest slamming, room shaking bass in the LFE channel falls in the 30-70hz range anyways, and given the size of the room, I should have no problems getting enough clean output.

I took a few measurements yesterday afternoon of the speakers only and the Audyssey corrected bass response from the l/r is fairly consistent from 30hz-200hz across the entire back half of the room, considering nobody sits on the front half, this might work out better. I’ll run some cea 2010 bursts later today and check the headroom, if I can get enough spl (112dB by my calculations) with just the fronts from 30hz on up without distortion, there’d be no reason to use a sub in the bedroom setup. Audyssey automatically filters out content below the measured f3, so there shouldn’t be any issues with frequencies below the box tuning causing unloading.

Eliminating the subs was intended as a joke, but in all seriousness might actually be an *easier* solution. We've only hit the tip of the iceberg in terms of data needed to properly integrate subs, and despite my good intentions, I've yet to be able to explain the importance of these processes via forum. As is often the case, the discussion overwhelms and the initiative to do the necessary work gets lost. Hey, I get it... I'm great at overloading myself!

But as a fellow owner of ML-TL speakers, the speakers measure great but the room is in control. I require subwoofers to get even bass just across the couch, which has nothing to do with awesome output of the Phil 3's which are run full range. That's just the nature of bass reproduction in small rooms!

If you are still serious about taking measurements and want to see where this thread will go, then I encourage you to try and provide as much data on your room as you can and see what we can do!

I'm heading out town Monday and will have limited computer access for more than a week. So hopefully you're planning on an audio weekend!

 

[TLS Guy]

Eliminating the subs was intended as a joke, but in all seriousness might actually be an *easier* solution. We've only hit the tip of the iceberg in terms of data needed to properly integrate subs, and despite my good intentions, I've yet to be able to explain the importance of these processes via forum. As is often the case, the discussion overwhelms and the initiative to do the necessary work gets lost. Hey, I get it... I'm great at overloading myself!

But as a fellow owner of ML-TL speakers, the speakers measure great but the room is in control. I require subwoofers to get even bass just across the couch, which has nothing to do with awesome output of the Phil 3's which are run full range. That's just the nature of bass reproduction in small rooms!

If you are still serious about taking measurements and want to see where this thread will go, then I encourage you to try and provide as much data on your room as you can and see what we can do!

I'm heading out town Monday and will have limited computer access for more than a week. So hopefully you're planning on an audio weekend!

I'm sorry, but I do not recognize mass loaded TLs as pipes. You can call them TLs if you want, but they DO NOT radiate as pipes. They have far more in common with Helmholtz resonators than pipes. So they are modified Helmholtz devices and NOT gedeckt pipes from the physics of the way they behave. So they will radiate as a Helmhotz resonator and not a gedeckt pipe. That is really important. If you hang around an organ builder for a while you will understand the difference.
Properly designed TL speakers that are gedeckt pipes sound totally different to other loadings in the room, with highly positive benefits.

The problem is that very few have ever heard a TL speaker I'm talking about that radiates from open pipes in the last two octaves and a bit. As far as I can tell only myself and the late John Wright have built dual TLs that acoustically hand over and cover the last two and a half octaves or so from speaking pipes.

 

[highfigh]

Any idea what could be causing the loss below 40hz? This is sitting center left of the midpoint of the back wall. The phase response doesn’t suggest a room null spot, and neither does the group delay.

It almost looks similar to the bass leakage effect one sees sitting/placing a sub or speaker near an opening to another room. The dip is down almost 48 dB/octave

In your first post, you wrote that the room "is well treated with Auralex..."- care to expand on that? If it's possible to run REW without the treatment, it would be good to see the response, or maybe you have files showing that.

If the room has open doorways to other rooms, you seem to have forgotten than the room's response isn't limited to that room, alone. Bass pressurizes the air and because of this, those other spaces are part of the room. Think of the room with the speakers as a large speaker cabinet and the doorway as a port, tuned to some unknown frequency. If it's a hallway, it's tuned to a different frequency from that of a simple doorway to another room.

Here's an interesting room mode calculator- among other info, it includes the surface area that would need to be treated in a room of your size in order to reach various RT60 ratings (use the drop down and choose the models for music) and a 3d representation, which can be rotated and with the keyboard showing where the modes exist and the keys allow hearing the notes. When you move the cursor to the mode, the 3d model shows where they are, in the room.

https://amcoustics.com/tools/amroc?l=12&w=11&h=8&ft=true&r60=0.6

 

[TheWarrior]

I'm sorry, but I do not recognize mass loaded TLs as pipes. You can call them TLs if you want, but they DO NOT radiate as pipes. They have far more in common with Helmholtz resonators than pipes. So they are modified Helmholtz devices and NOT gedeckt pipes from the physics o the way they behave. SO they will radiate as a Helmhotz resonator and not a gedeckt pipe. That is really important. If you hang around an organ buider for a while you will understand the difference.
Properly designed TL speakers that are gedeckt pipes sound totally different to other loadings in the room, with highly positive benefits.

The problem is that very few have ever heard a TL speaker I'm talking about that radiates from open pipes in the last two octaves and a bit. As far as I can tell only myself and the late John Wright have built dual TLs that acoustically hand over over and cover the last two and a half octaves or so from speaking pipes.

I thought I recalled yours being mass loaded from the construction photos you sent way back when?

 

[TLS Guy]

I thought I recalled yours being mass loaded from the construction photos you sent way back when?

I have never built a mass loaded TL.

Shorter line of mains.

Long line being built round the short line.

Note the large ports at the open end of the long pipe.

The center channel line

There are no lines opening into resonant ported cavities.

 

[yepimonfire]

Eliminating the subs was intended as a joke, but in all seriousness might actually be an *easier* solution. We've only hit the tip of the iceberg in terms of data needed to properly integrate subs, and despite my good intentions, I've yet to be able to explain the importance of these processes via forum. As is often the case, the discussion overwhelms and the initiative to do the necessary work gets lost. Hey, I get it... I'm great at overloading myself!

But as a fellow owner of ML-TL speakers, the speakers measure great but the room is in control. I require subwoofers to get even bass just across the couch, which has nothing to do with awesome output of the Phil 3's which are run full range. That's just the nature of bass reproduction in small rooms!

If you are still serious about taking measurements and want to see where this thread will go, then I encourage you to try and provide as much data on your room as you can and see what we can do!

I'm heading out town Monday and will have limited computer access for more than a week. So hopefully you're planning on an audio weekend!

Okay, speakers do fine from about 45hz on up but definitely do not have the headroom necessary at 40hz and below to handle the +10dB LFE and bass management from the other 5 channels, at least not at the crazy levels I like watching movies at, so I'm going to have to just pick the best spot for the sub and use audyssey. The larger room had some gain at about 28hz, which helped prop up the output in the 30hz range, but this room is all 53hz being square.

The response with audyssey isn't 100% perfect, but it's definitely a massive improvement that takes it from unbearably bad to reasonably flat sounding, and does manage to correct most of the 40hz roll off issue. Someone is going to kindly allow me to borrow a second subwoofer so maybe that will help even out some of the response issues and help audyssey do a better job. If it does, I'll at least know another sub or two thrown in is the answer.

Either way, there's no way this room will ever have anything close to resembling flat bass without room correction.

Sent from my LM-X210(G) using Tapatalk

 

[TheWarrior]

Okay, speakers do fine from about 45hz on up but definitely do not have the headroom necessary at 40hz and below to handle the +10dB LFE and bass management from the other 5 channels, at least not at the crazy levels I like watching movies at, so I'm going to have to just pick the best spot for the sub and use audyssey. The larger room had some gain at about 28hz, which helped prop up the output in the 30hz range, but this room is all 53hz being square.

The response with audyssey isn't 100% perfect, but it's definitely a massive improvement that takes it from unbearably bad to reasonably flat sounding, and does manage to correct most of the 40hz roll off issue. Someone is going to kindly allow me to borrow a second subwoofer so maybe that will help even out some of the response issues and help audyssey do a better job. If it does, I'll at least know another sub or two thrown in is the answer.

Either way, there's no way this room will ever have anything close to resembling flat bass without room correction.

Sent from my LM-X210(G) using Tapatalk

Sounds good. When you're ready to tinker, hit me up!

 

[TheWarrior]

I have never built a mass loaded TL.

Shorter line of mains.



Long line being built round the short line.







Note the large ports at the open end of the long pipe.


The center channel line



There are no lines opening into resonant ported cavities.

Whoops, brain error.... I've only studied pipes, completely forgot the coupling chamber just exits into fluff.

 

[yepimonfire]

Sounds good. When you're ready to tinker, hit me up!

Oh ill be tinkering away. Should be a nice collection of results waiting in this thread when you return.

Sent from my LM-X210(G) using Tapatalk