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post #1 of 35 Old 01-13-2020, 12:51 PM - Thread Starter
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Impact of Cascading Crossovers on LFE

Hi All,
Simple FYI post on the impact of cascading crossovers that I thought was slightly interesting. I've been playing around with them after reading Mikes excellent guide and decided to do some REW measurements.

I used 24db slopes on the sub crossovers. FWIW this is a -5db sweep, subs running 0db hot.

In the attachment:

Orange - No Audyssey - Side observation, for this measurment, I had a door open at the far end of my HT/basement area at the top of the stairs, oddly closing the door creates that weird null at 19.5hz, for the other measurements I had the door open, it flattens my response - 6500+ cu foot room so I opted to take the flatter response over room pressurization). Thoughts on that anomoly appreciated, I would have expected a better response with the door closed.

Blue - Post Audy xt32 no Cascading Xover
Green - Post Audy xt32 - 100hz Cascading Xover
Red - Post Audy xt32 - 80 hz Cascading Xover

The most interesting takeaway here to me was that there is a pretty significant impact below the crossover point down into the mid 40hz when using in particular the 80hz Xover.

Any other thoughts and experiences on CC? I am still playing around with whats best.
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post #2 of 35 Old 01-13-2020, 12:57 PM
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I suggest to try a higher cascade: 120hz or higher
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post #3 of 35 Old 01-13-2020, 01:48 PM
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Originally Posted by Matt Fowler View Post
Hi All,
Simple FYI post on the impact of cascading crossovers that I thought was slightly interesting. I've been playing around with them after reading Mikes excellent guide and decided to do some REW measurements.

I used 24db slopes on the sub crossovers. FWIW this is a -5db sweep, subs running 0db hot.

In the attachment:

Orange - No Audyssey - Side observation, for this measurment, I had a door open at the far end of my HT/basement area at the top of the stairs, oddly closing the door creates that weird null at 19.5hz, for the other measurements I had the door open, it flattens my response - 6500+ cu foot room so I opted to take the flatter response over room pressurization). Thoughts on that anomoly appreciated, I would have expected a better response with the door closed.

Blue - Post Audy xt32 no Cascading Xover
Green - Post Audy xt32 - 100hz Cascading Xover
Red - Post Audy xt32 - 80 hz Cascading Xover

The most interesting takeaway here to me was that there is a pretty significant impact below the crossover point down into the mid 40hz when using in particular the 80hz Xover.

Any other thoughts and experiences on CC? I am still playing around with whats best.

Hi Matt,

That's interesting! As you know from reading the Guide, I got my best results at 80Hz, just as you did. I think that is the more common experience, judging from the extensive feedback I have received. Although I was pleased to have slightly more impact below the 80Hz crossover, the most valuable aspect for me was the overall increase in mid-bass clarity, and especially with respect to dialogue clarity.

It appears that we have similar rooms, as mine is also just a little over 6,000^3. I had a similar experience when I experimented with opening or closing doors. I can make my room pretty tightly sealed if I want to, or I can open a couple of different doors.

At one time, I experimented with opening two doors, to different widths, and found that I could tune my room to some extent, increasing the <20Hz SPL, with reasonably specific door widths. As I moved to even more powerful ported subs, I stopped experimenting with that. But, I think that is what you experienced. You were actually tuning your room somewhat.

Regards,
Mike

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post #4 of 35 Old 01-13-2020, 02:05 PM - Thread Starter
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Hi Matt,

That's interesting! As you know from reading the Guide, I got my best results at 80Hz with 80 hz xocer, just as you did. I think that is the more common experience, judging from the extensive feedback I have received. Although I was pleased to have slightly more impact below the 80Hz crossover, the most valuable aspect for me was the overall increase in mid-bass clarity, and especially with respect to dialogue clarity.

It appears that we have similar rooms, as mine is also just a little over 6,000^3. I had a similar experience when I experimented with opening or closing doors. I can make my room pretty tightly sealed if I want to, or I can open a couple of different doors.

At one time, I experimented with opening two doors, to different widths, and found that I could tune my room to some extent, increasing the <20Hz SPL, with reasonably specific door widths. As I moved to even more powerful ported subs, I stopped experimenting with that. But, I think that is what you experienced. You were actually tuning your room somewhat.

Regards,
Mike
Well when I say "impact" I mean that from 40-80 there was a significant reduction in output, IE at 60hz we are down 2db(edit) vs using no CC. Based on measurements alone I may actually end up with 90 or 100 as I'm not sure if we want to reduce volume so much from 40-80. I'm way more concerned with reducing volume over 80, but 24 db is the steepest slope I can employ and the type of slope can't be switched such that it has less impact below 80hz.
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post #5 of 35 Old 01-13-2020, 03:06 PM
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Well when I say "impact" I mean that from 40-80 there was a significant reduction in output, IE at 60hz we are down 2db(edit) vs using no CC. Based on measurements alone I may actually end up with 90 or 100 as I'm not sure if we want to reduce volume so much from 40-80. I'm way more concerned with reducing volume over 80, but 24 db is the steepest slope I can employ and the type of slope can't be switched such that it has less impact below 80hz.

Hi Matt,

I probably should have added more detail to my post, although I talked about this a little bit in the Guide. I think that cascading crossovers are most helpful where someone is employing a really significant subwoofer boost. Different people will find different uses for it, at different frequencies, but the amount of subwoofer boost someone is using can make a difference.

In my case, I am generally using a very substantial sub boost, so the fact that my subs begin to roll-off a little quicker below 80Hz is negligible compared to the total amount of the boost. And, I find that a little more perceived impact occurs in the 50Hz to 70Hz range, which is where I feel the most chest punch. I also augment my mid-bass a little by adding some bass to my front speakers with my Tone Control. That also helps a bit!

The biggest things I am trying to do with cascading crossovers are to keep my LFE lower, in order to obtain more mid-bass clarity, and to keep my subwoofer boost out of my center channel, in order to obtain more dialogue clarity. But, as with everything in audio, all of this is strictly a YMMV issue! You should definitely use 90Hz, or whatever sounds and feels best to you. I certainly wouldn't want to sacrifice any chest punch.

Regards,
Mike
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post #6 of 35 Old 01-13-2020, 04:44 PM - Thread Starter
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Hi Matt,

I probably should have added more detail to my post, although I talked about this a little bit in the Guide. I think that cascading crossovers are most helpful where someone is employing a really significant subwoofer boost. Different people will find different uses for it, at different frequencies, but the amount of subwoofer boost someone is using can make a difference.

In my case, I am generally using a very substantial sub boost, so the fact that my subs begin to roll-off a little quicker below 80Hz is negligible compared to the total amount of the boost. And, I find that a little more perceived impact occurs in the 50Hz to 70Hz range, which is where I feel the most chest punch. I also augment my mid-bass a little by adding some bass to my front speakers with my Tone Control. That also helps a bit!

The biggest things I am trying to do with cascading crossovers are to keep my LFE lower, in order to obtain more mid-bass clarity, and to keep my subwoofer boost out of my center channel, in order to obtain more dialogue clarity. But, as with everything in audio, all of this is strictly a YMMV issue! You should definitely use 90Hz, or whatever sounds and feels best to you. I certainly wouldn't want to sacrifice any chest punch.

Regards,
Mike

Yeah I run hot (0 to -8 MV...6-13db hot with dynamic EQ off and I BEQ every movie I can) so I'm in the same boat as you are. The OCD tweaking never seems to end. I'm not even sure 80hz isn't the best for my setup, just trying to get some feedback from others on it. Its nice to have some things to play with that are free tweaks and CC is certainly one of them.
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I have not seen many REW examples of cascading crossovers but interesting. It seems to me the biggest issue that CC attempts to address is the poor blending of the sub and LCR channels when the sub is boosted substantially. While this does appear to work for many subjectively based on avs reports it does have the potential of unintended cancellation. I for one had a substantial loss of mid bass impact so don’t use it although never verified with REW. Another approach to potentially address this is to EQ in a “tilted” bass curve. Call it what you want- house curve, Harmon curve, etc. If you are an Audyssey and multieq app user, Avs member batpig discovered a rather simple method of doing this with just a single control point. If you drag down the highest sub frequency in the curve editor, which is 250hz, it has the effect of actually tilting the curve rather than just bringing down the top end. If you drop the top end down about 8db you wind up with about a 4db boost above baseline at the low end (~20hz) and down about 4db around typical crossover frequency 80-90hz. If you then boost sub channel by 4db the sub and main channels match up and you have a nice rising bass response. You can still add more sub boost to taste but you still wind up with a better blend at the crossover than you otherwise would. This seems to work well for me without the side effect of any cancellation. I’m sure you could create similar eq curves with something like a mini dsp but this is super simple with the Audyssey app.
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I have not seen many REW examples of cascading crossovers but interesting. It seems to me the biggest issue that CC attempts to address is the poor blending of the sub and LCR channels when the sub is boosted substantially. While this does appear to work for many subjectively based on avs reports it does have the potential of unintended cancellation. I for one had a substantial loss of mid bass impact so don’t use it although never verified with REW. Another approach to potentially address this is to EQ in a “tilted” bass curve. Call it what you want- house curve, Harmon curve, etc. If you are an Audyssey and multieq app user, Avs member batpig discovered a rather simple method of doing this with just a single control point. If you drag down the highest sub frequency in the curve editor, which is 250hz, it has the effect of actually tilting the curve rather than just bringing down the top end. If you drop the top end down about 8db you wind up with about a 4db boost above baseline at the low end (~20hz) and down about 4db around typical crossover frequency 80-90hz. If you then boost sub channel by 4db the sub and main channels match up and you have a nice rising bass response. You can still add more sub boost to taste but you still wind up with a better blend at the crossover than you otherwise would. This seems to work well for me without the side effect of any cancellation. I’m sure you could create similar eq curves with something like a mini dsp but this is super simple with the Audyssey app.
Good stuff, yeah I've never had much luck playing with the curve editor on the multi-eq app, its pretty clumsy. I may give that a shot.

Also nice to see another Cleveland member, I'm out in Kirtland.
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post #9 of 35 Old 01-13-2020, 10:23 PM
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Good stuff, yeah I've never had much luck playing with the curve editor on the multi-eq app, its pretty clumsy. I may give that a shot.

Also nice to see another Cleveland member, I'm out in Kirtland.
Cool. I work in Willoughby Hills 3 days a week so pretty close to you.
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While I have my REW charts in front of everyone, I want to try and better understand the impact of room correction (XT32), EQ, and net impact on FR headroom wise. In my case we are getting cuts from 40hz down and boosts from roughly 60 -75 peaking what is probably a 4db boost using no CC.

1. Say my area of focus in a particular movie is sub 40hz. Massive hits come at 17hz. Am I right in assuming I'm only losing headroom in the 17hz region if theres also transients occurring in the 60-75hz range where boost is happening?
2. Theoretically if we have a PEQ cut of 2db at 25hz and a PEQ boost of 2db at 60hz, assume same Q for both then do we still have a net headroom gain because 25hz is harder on the amplifier and we have lessoned the low end burden?

Ultimately I could use my mini dsp to do sub EQ, I want to do as little boosting as possible short of running the sub hot and using BEQ. With the above questions being the context do you guys think that boost from 60-75 by xt32 is having a major negative impact on headroom overall? I have room issues in the 60-75 hz region, apparently not a pure null as XT32 was able to defeat it based on the post XT32 measurements. Just wondering at what cost to headroom especially since I run very hot and often near or at reference. I'm assuming major LFE scenes nearly always have 60-75hz transients.

Hopefully any insight can be helpful to others as well in determining whether they should manually EQ their subs vs take their room correction result. Manual EQ vs Room Correction and the impacts of EQ on headroom and the FR is one area on the forums I haven't yet found great answers too. Or maybe my googling abilities just need to improve!

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post #11 of 35 Old 01-14-2020, 08:43 AM
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Originally Posted by Matt Fowler View Post
While I have my REW charts in front of everyone, I want to try and better understand the impact of room correction (XT32), EQ, and net impact on FR headroom wise. In my case we are getting cuts from 40hz down and boosts from roughly 60 -75 peaking what is probably a 4db boost using no CC.

1. Say my area of focus in a particular movie is sub 40hz. Massive hits come at 17hz. Am I right in assuming I'm only losing headroom in the 17hz region if theres also transients occurring in the 60-75hz range where boost is happening?
2. Theoretically if we have a PEQ cut of 2db at 25hz and a PEQ boost of 2db at 60hz, assume same Q for both then do we still have a net headroom gain because 25hz is harder on the amplifier and we have lessoned the low end burden?

Ultimately I could use my mini dsp to do sub EQ, I want to do as little boosting as possible short of running the sub hot and using BEQ. With the above questions being the context do you guys think that boost from 60-75 by xt32 is having a major negative impact on headroom overall? I have room issues in the 60-75 hz region, apparently not a pure null as XT32 was able to defeat it based on the post XT32 measurements. Just wondering at what cost to headroom especially since I run very hot and often near or at reference. I'm assuming major LFE scenes nearly always have 60-75hz transients.

Hopefully any insight can be helpful to others as well in determining whether they should manually EQ their subs vs take their room correction result. Manual EQ vs Room Correction and the impacts of EQ on headroom and the FR is one area on the forums I haven't yet found great answers too. Or maybe my googling abilities just need to improve!

Hi Matt,

I think that you are asking some very good questions (and answering some of them the same way that I would). I don't know that a Google search would turn-up anything on this subject, but I have been involved in some previous discussions along the same lines.

I believe that boosts in the 60-75Hz range will exact less toll on overall headroom than similar boosts down low would. And, cuts down low should free-up some headroom. But, I wouldn't want to try to develop any sort of formula for this.

If I wanted to see the net effect of my cuts and boosts on the overall headroom, I would do compression testing with all of the EQ in place, and with my subwoofer boost implemented. I would measure exactly as I would be listening. That would show you at what volume levels (and frequencies) you are running out of headroom.

The transient short-term nature of some low-frequency peaks might still make potential compression inaudible, but you would be able to get a pretty good general idea of how much headroom you have available, at a particular listening level.

Regards,
Mike
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post #12 of 35 Old 01-14-2020, 08:55 AM
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Good stuff, yeah I've never had much luck playing with the curve editor on the multi-eq app, its pretty clumsy. I may give that a shot.

Also nice to see another Cleveland member, I'm out in Kirtland.
If you are interested here is Batpig's initial post and there is some subsequent discussion.

https://www.avsforum.com/forum/90-re...l#post59000616
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post #13 of 35 Old 01-14-2020, 10:05 AM - Thread Starter
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Hi Matt,

I think that you are asking some very good questions (and answering some of them the same way that I would). I don't know that a Google search would turn-up anything on this subject, but I have been involved in some previous discussions along the same lines.

I believe that boosts in the 60-75Hz range will exact less toll on overall headroom than similar boosts down low would. And, cuts down low should free-up some headroom. But, I wouldn't want to try to develop any sort of formula for this.

If I wanted to see the net effect of my cuts and boosts on the overall headroom, I would do compression testing with all of the EQ in place, and with my subwoofer boost implemented. I would measure exactly as I would be listening. That would show you at what volume levels (and frequencies) you are running out of headroom.

The transient short-term nature of some low-frequency peaks might still make potential compression inaudible, but you would be able to get a pretty good general idea of how much headroom you have available, at a particular listening level.

Regards,
Mike
I have a compression test handy actually. Thoughts on what you would do to optimize? This is post audyssey. When I started to compress heavily I limited the range just to determine Max output at the range that still had some juice left. This is dual PB3000s in 6500+ cu ft on concrete. Sweeps start at 0db MV and go to 14db hot. The first 2 sweeps are +5 then +2 and + 2. So for example brown line is 10db hot at reference level. This is using U-mik and -12dbfs sweep volume.

These sweeps use 80 hz CC.

Keep in mind I do use BEQ and I have crowson motion actuators that do a superlative job handling TR below 20hz and enhancing TR for 20-80 (I use mini dsp to cut it off sooner or later depending on the BEQ file and movie type)
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post #14 of 35 Old 01-14-2020, 01:06 PM
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I have a compression test handy actually. Thoughts on what you would do to optimize? This is post audyssey. When I started to compress heavily I limited the range just to determine Max output at the range that still had some juice left. This is dual PB3000s in 6500+ cu ft on concrete. Sweeps start at 0db MV and go to 14db hot. The first 2 sweeps are +5 then +2 and + 2. So for example brown line is 10db hot at reference level. This is using U-mik and -12dbfs sweep volume.

These sweeps use 80 hz CC.

Keep in mind I do use BEQ and I have crowson motion actuators that do a superlative job handling TR below 20hz and enhancing TR for 20-80 (I use mini dsp to cut it off sooner or later depending on the BEQ file and movie type)

Hi Matt,

I imagine that you probably see what I see. The first blue line, which is at about 108dB for most of the range below 70Hz, is really the only smooth one. You start to lose the frequencies below 30Hz, as you go up from there, and by the time that you are employing a lot of subwoofer boost, you are just playing the frequencies between about 25Hz and 55Hz, probably with a good bit of distortion, as well as audible compression.

FWIW, I think that those dual PB3000's are doing a terrific job to give you such a good FR, at 108dB from about 18Hz up, in a 6500^3 room. But frankly, I think that they are over-matched by the sheer room volume, and by your interest in loud listening levels and significant subwoofer boosts.

I really think that someone who enjoys using BEQ needs more subwoofer firepower than you currently have. I think that you especially need more <20Hz output. SPL and TR aren't exactly the same thing, and I think we need both to fully appreciate low-bass special effects.

I am reluctant to encourage someone else to spend money on more powerful subwoofers (said no one on AVS, ever ) but if you ever want to pursue some other options, I will be glad to try to help.

Regards,
Mike

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post #15 of 35 Old 01-14-2020, 01:19 PM - Thread Starter
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Originally Posted by mthomas47 View Post
Hi Matt,

I imagine that you probably see what I see. The first blue line, which is at about 108dB for most of the range below 70Hz, is really the only smooth one. You start to lose the frequencies below 30Hz, as you go up from there, and by the time that you are employing a lot of subwoofer boost, you are just playing the frequencies between about 25Hz and 55Hz, probably with a good bit of distortion, as well as audible compression.

FWIW, I think that those dual PB3000's are doing a terrific job to give you such a good FR, at 108dB from about 18Hz up, in a 6500^3 room. But frankly, I think that they are over-matched by the sheer room volume, and by your interest in loud listening levels and significant subwoofer boosts.

I really think that someone who enjoys using BEQ needs more subwoofer firepower than you currently have. I think that you especially need more <20Hz output. SPL and TR aren't exactly the same thing, and I think we need both to fully appreciate low-bass special effects.

I am reluctant to encourage someone else to spend money on more powerful subwoofers (said no one on AVS, ever ) but if you ever want to pursue some other options, I will be glad to try to help.

Regards,
Mike
Ugh my wife would kill me. KILLLL ME

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post #16 of 35 Old 01-14-2020, 01:49 PM - Thread Starter
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Ugh my wife would kill me. KILLLL ME
I have over a month left in my 1 year upgrade period for my first PB3000. Until July for the 2nd.

If I'm doing it I'm going all in and straight to the 16 ultra. I just don't know if I can justify $2000 for basically sub 20hz and lower. 25 and up is not a massive difference between the 3000 and the 16 ultra. 4db at 25hz.... EDIT... Actually its about 5db better at 31hz so thats a big deal. At 50 and up the 3000 is actually better oddly enough.
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post #17 of 35 Old 01-14-2020, 02:08 PM
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Originally Posted by Matt Fowler View Post
I have over a month left in my 1 year upgrade period for my first PB3000. Until July for the 2nd.

If I'm doing it I'm going all in and straight to the 16 ultra. I just don't know if I can justify $2000 for basically sub 20hz and lower. 25 and up is not a massive difference between the 3000 and the 16 ultra. 4db at 25hz.... At 50 and up its no different.
< 20Hz is expensive but also enjoyable. You clearly have demonstrated you want the best performance you can get with all the effort you have put in with REW, mini DSP, etc and have an otherwise very good setup. If you can afford to do so and think you can survive the marital stress do it and be done with it. AVS will notoriously spend your money but it is usually for a good cause. I started with a single PB-1000. Spent some time here and had dual PC-4000s after a while.

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< 20Hz is expensive but also enjoyable. You clearly have demonstrated you want the best performance you can get with all the effort you have put in with REW, mini DSP, etc and have an otherwise very good setup. If you can afford to do so and think you can survive the marital stress do it and be done with it. AVS will notoriously spend your money but it is usually for a good cause. I started with a single PB-1000. Spent some time here and had dual PC-4000s after a while.
I too started with a single PB1000 a little over a year ago lol.

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Originally Posted by mthomas47 View Post
Hi Matt,

I imagine that you probably see what I see. The first blue line, which is at about 108dB for most of the range below 70Hz, is really the only smooth one. You start to lose the frequencies below 30Hz, as you go up from there, and by the time that you are employing a lot of subwoofer boost, you are just playing the frequencies between about 25Hz and 55Hz, probably with a good bit of distortion, as well as audible compression.

FWIW, I think that those dual PB3000's are doing a terrific job to give you such a good FR, at 108dB from about 18Hz up, in a 6500^3 room. But frankly, I think that they are over-matched by the sheer room volume, and by your interest in loud listening levels and significant subwoofer boosts.

I really think that someone who enjoys using BEQ needs more subwoofer firepower than you currently have. I think that you especially need more <20Hz output. SPL and TR aren't exactly the same thing, and I think we need both to fully appreciate low-bass special effects.

I am reluctant to encourage someone else to spend money on more powerful subwoofers (said no one on AVS, ever ) but if you ever want to pursue some other options, I will be glad to try to help.

Regards,
Mike
So I just watched a Dracula on Netflix a bit ago and the experience was pretty sensational, I heard no ill sounds and the mix and TR seemed top shelf. It could be I just don't know what distorted bass sounds like.

So Mike, using my compression chart and my below ramblings can you convince me what I'd gain from upgrading to pb16ultras?

TR is covered down to 5hz by the Crowsons, SPL is covered by PB3000s over 20hz (114.5 max output at 20hz (possibly distorted but I don't know if I could describe what that sounds like), should be good enough).


1. I like to run 10db hot for alot of material(that would be the brown line). My system sounds/feels great to me as is and for most things I don't hear distortion at that level. If I do its port chuff and the worst offender in my experience is A Quiet Place. I back that one down to 6-8db hot. 99 percent of movies I don't get port chuff. For example I don't get it in BR 2049 intro until I'm running 11db hot.

2. If there is audible compression I don't know what it sounds like perhaps because its masked by 20-55hz being loud and the crowsons being capable of producing TR that feels like my teeth are vibrating if I turn them up.

3. Even the best subs start compressing when you go low enough. So if we have a 10hz note in a movie that is -15dbfs (doable with BEQ) or even lower then surely all but the top tier of ID subs are going to compress. At that point are even those subs suffering in the 20-40 range) due to the compression happening at 10hz?

4. One thing I haven't experienced is a sensation of true pressurization and its always something I've wondered about. Are dual PB16s even enough to do this in a room as large as mine? I'm sure I've experienced close to 120db in room, I know I've hit 117db with a C weighted mic (Sicaro explosion near start) that would be down 3db at 31hz and 6db at 25hz. I didn't feel the air move when that happened. Is air movement pressurization? Would have thought 117-120db in the 30hz range would have been enough? And is sub 20hz extreme volume necessary to feel it? At what frequencies do we start to feel pressurization? Is 120db in a 3k cu ft room going to be different pressurization vs 120db in a 6k room cu ft room? Is it possible to pressurize a 6500 cu ft room w/o JTR Captivators?

Also I really appreciate your generosity in answering my ramblings and your contributions to the community in general. I hope others have the same questions as me and just haven't felt like articulating what I am above.

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Originally Posted by Matt Fowler View Post
So I just watched a Dracula on Netflix a bit ago and the experience was pretty sensational, I heard no ill sounds and the mix and TR seemed top shelf. It could be I just don't know what distorted bass sounds like.

So Mike, using my compression chart and my below ramblings can you convince me what I'd gain from upgrading to pb16ultras?

TR is covered down to 5hz by the Crowsons, SPL is covered by PB3000s over 20hz (114.5 max output at 20hz (possibly distorted but I don't know if I could describe what that sounds like), should be good enough).


1. I like to run 10db hot for alot of material(that would be the brown line). My system sounds/feels great to me as is and for most things I don't hear distortion at that level. If I do its port chuff and the worst offender in my experience is A Quiet Place. I back that one down to 6-8db hot. 99 percent of movies I don't get port chuff. For example I don't get it in BR 2049 intro until I'm running 11db hot.

2. If there is audible compression I don't know what it sounds like perhaps because its masked by 20-55hz being loud and the crowsons being capable of producing TR that feels like my teeth are vibrating if I turn them up.

3. Even the best subs start compressing when you go low enough. So if we have a 10hz note in a movie that is -15dbfs (doable with BEQ) or even lower then surely all but the top tier of ID subs are going to compress. At that point are even those subs suffering in the 20-40 range) due to the compression happening at 10hz?

4. One thing I haven't experienced is a sensation of true pressurization and its always something I've wondered about. Are dual PB16s even enough to do this in a room as large as mine? I'm sure I've experienced close to 120db in room, I know I've hit 117db with a C weighted mic (Sicaro explosion near start) that would be down 3db at 31hz and 6db at 25hz. I didn't feel the air move when that happened. Is air movement pressurization? Would have thought 117-120db in the 30hz range would have been enough? And is sub 20hz extreme volume necessary to feel it? At what frequencies do we start to feel pressurization? Is 120db in a 3k cu ft room going to be different pressurization vs 120db in a 6k room cu ft room? Is it possible to pressurize a 6500 cu ft room w/o JTR Captivators?

Also I really appreciate your generosity in answering my ramblings and your contributions to the community in general. I hope others have the same questions as me and just haven't felt like articulating what I am above.

Hi Matt,

First of all, you are very welcome for any help I have provided! Trying to answer all (or even some) of your questions will be quite an undertaking, but I will give it a shot.

Part 1:

Let's start with room pressurization. Room pressurization occurs when the air in the room literally becomes compressed, or condensed, due to air pressure. The sensation we feel is similar to that which we feel when an airplane cabin pressurizes. First, our ears start to tingle, and then our ear drums feel substantial pressure, and ultimately we may feel pressure in the head and face. I don't particularly like that sensation, but I have experienced it in my 6,000^3 room.

It is easiest to experience cabin pressurization in a sealed room, and smaller rooms can be pressurized more easily than large ones, partly due to room gain. Although I haven't attempted to measure the exact SPL (or frequency) at which room pressurization occurs in my room, I believe it happens with content in about the low to mid-teens, with about 115dB (or more) of volume at those frequencies. The thing about ported subs, though, is that we usually feel so much tactile ULF, before we feel cabin pressurization, that we never need to go quite that far. I certainly don't anyway!

With sealed subs, ULF TR can be somewhat insidious. It may not be an extremely overt sensation, at the listening position, as it is with ported subwoofers, although there may be vibrations occurring in the room or elsewhere in the house. Instead, with sealed subs, there is usually just a gradual build-up of pressure (from the right SPL at the right frequencies) until we feel our ears start to tingle, and then the rest of the sensations I described. Room vibrations may also be occurring, especially on a suspended wood floor. With enough pressure, we can feel it in other parts of our bodies, as well. This is one of those YMMV issues. As noted, those sensations are not something I particularly care for.

What I do like is the sensation of ULF energy running throughout the whole room, even on a concrete floor. With low-tuned ported subs, playing the right frequencies at the right volume levels, that can be a very forceful and memorable sensation. In my room, I have described it as making the whole room ripple with ULF energy. And, it is not exactly the same sensation that you feel with your Crowson's, even as good as they are. It's not the sensation of you and your chair moving, as much as it is the sensation of energy (air particles creating particle velocity) moving within the room.

Brian Ding, of Rythmik, described the difference as similar to the sensation of having a baseball thrown close to our heads. We may hear the passage of the ball through the air, but we will also feel the energy of the air displacement occurring as the ball moves through the air. Brian went on to say that film mixers were well aware of the difference between sound and sensation and developed their low-frequency special effects in movies with that in mind.

I can't speak to that last part, but I can say that very low-frequency sounds, and the tactile sensations that accompany them, are not identical. They are hard for our brains to separate as two discrete events (as I think we can more easily with chest punch) but we are aware that both sound and sensation are occurring. I think it is especially difficult to separate <20Hz sounds and sensations, and yet in my opinion, that is where a lot of the real magic happens.

Thunder from a nearby lightening strike is a great natural example of ULF SPL and TR. We hear the peal of the thunder, and we feel the whole house vibrate from the massive displacement of air which accompanies it. I could try to add more detail to this part of the discussion, but I think I have made the point. If you haven't experienced the combination of ULF SPL and TR in your HT, you may not know what you are missing.

Part 2:

Now, let me try to talk about subwoofers a little. Yes, PB16's can theoretically pressurize a 6,500^3 room, as they can in my 6,000^3 room, although once again I would forget about the idea of room pressurization as a single specific goal, if I were you. There is a lot of ULF TR that can occur with ported subs, before room pressurization is achieved. Thank goodness, for those of us who don't enjoy cabin pressurization as much! (I have flown a lot, and done some scuba diving, and having my ear drums tingle and my ears stopped-up is not one of my all-time favorite sensations.)

I have the equivalent of four PB16's in my 6,000^3 room, on concrete. (Three PB16's and a PB4000 located 22" behind my listening chair.) My room is very heavily-constructed, which adds to the boundary reinforcement and mid-bass containment, and I can seal the room when I want to. Could I get quite as much bass into the low-teens, as I would like (the low-teens is really what I want for most movies) with only two PB16's? I'm not sure.

I already had four PB13's when the PB16's came out, so it was easy for me just to move-up a model, and later to replace my nearfield PB13 with a PB4000. As a side note, I not only get a great frequency response with four subs, and extra TR with a nearfield one, I also get great bass envelopment with the way my room is set-up.

It's possible that you will need to use the one-year SVS upgrade plan to move to PB16's, or that you will prefer to stay with SVS subs for other reasons. Personally, I really like the form factor, piano black finish, and digital controls and display. But, I was able to spread my expenditures and upgrades out over time, so I could afford to get four of what I wanted. If I were advising you, knowing what I do about your room, listening levels, and bass preferences, would I advise you to upgrade to dual PB16's? Once again, I'm not sure.

Leaving form/aesthetic/feature/ease of upgrade considerations completely out of the equation, I would advise you to buy dual Cap 2400ULF's. (As you may know, they have a 10Hz port tune, with a lot of DSP pushed into the lowest-frequencies.) They are more costly than the PB16's, and you would have to independently sell your PB3000's, but they are available in either a low version or a tall version. (The tall version can also just lay on its side.) There would be a considerable performance difference with those subs.

The PB16's would stay even with, or slightly better than, the Cap 2400 from about 30Hz down to about 14 or 15Hz. But, the Cap 2400 would be about 5dB more powerful in the mid-bass frequencies, and would absolutely smoke the PB16 below about 14Hz. In a 6500^3 room, where your pressure vessel gain (PVG is the strongest form of room gain) will start a fraction below 15Hz, I think that dual Cap 2400's would be a better solution for you than dual PB16's.

The new PSA TV3612's would also be a very good solution for you. Those are dual pro-audio 18" drivers, in a large cabinet volume, with a 13.5-14Hz port tune. They have a ton of mid-bass, and better low-frequency extension than the PB16's. They would be my second choice for your room, with the PB16's my third, based purely on SPL performance.

Sound signature and ULF TR are also considerations, though. And, these are somewhat subjective considerations, as are the observations which follow. The new PSA subs would have a slightly clearer sound signature and a more enveloping TR sensation, I think, compared to the Cap 2400's and the PB16's. The PSA subs might blend a little more with some content. The JTR subs would be more overt and violent, with the SVS subs a little more similar to JTR than to PSA. You really notice the <20Hz content, at high volume levels, when the JTR and SVS subs are playing.

I know that you said you had some work to do with your wife on this whole upgrade issue, which is still better than "She will kill me!" But, that is about the most objective answer to your questions that I can give you. I am lucky enough to be able to have just what I want right now, and it was pretty painless for me to get there. But, in trying to advise someone else, I need to leave aside my own situation and preferences, and just concentrate on performance factors.

If you need to stay with SVS, then a pair of PB16's may work perfectly well for you. But, I am much more certain that a pair of Cap 2400ULF's (or their slightly smaller 2400 siblings) will be able to energize your room with bass, and deliver the strong <20Hz SPL that you are lacking now. And, they will be able to do it with less compression and distortion.

The 15.5" driver, and lower amplifier power of the PB16, is just giving up a little too much for a full frequency response, head-to-head match-up, with the Cap 2400 in my opinion. It is possible to make-up most of the difference with additional PB16 multiples, but head-to-head, the advantage has to go to the JTR Cap 2400, and to the dual-driver PSA TV3612.

I hope this long post is helpful in clarifying some things that you and others may be curious about. If you want to understand more about room gain, or about some other things involving bass and subwoofers, additional explanations may be found in the Guide linked below.

Regards,
Mike

GUIDE TO SUBWOOFER CALIBRATION AND BASS PREFERENCES

* The Guide linked above is a comprehensive guide to Audio & HT systems, including:
Speaker placements & Room treatments; HT calibration & Room EQ; Room gain; Bass
Preferences; Subwoofer Buyer's Guide: Sealed/ported; ID subs; Subwoofer placement.

Last edited by mthomas47; 01-15-2020 at 02:43 PM.
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post #21 of 35 Old 01-15-2020, 02:40 PM - Thread Starter
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Originally Posted by mthomas47 View Post
Hi Matt,

First of all, you are very welcome for any help I have provided! Trying to answer all (or even some) of your questions will be quite an undertaking, but I will give it a shot.

Part 1:

Let's start with room pressurization. Room pressurization occurs when the air in the room literally becomes compressed, or condensed, due to air pressure. The sensation we feel is similar tho that which we feel when an airplane cabin pressurizes. First, our ears start to tingle, and then our ear drums feel substantial pressure, and ultimately we may feel pressure in the head and face. I don't particularly like that sensation, but I have experienced it in my 6,000^3 room.

It is easiest to experience cabin pressurization in a sealed room, and smaller rooms can be pressurized more easily than large ones, partly due to room gain. Although I haven't attempted to measure the exact SPL (or frequency) at which room pressurization occurs in my room, I believe it happens with content in about the low to mid-teens, with about 115dB (or more) of volume at those frequencies. The thing about ported subs, though, is that we usually feel so much tactile ULF, before we feel cabin pressurization, that we never need to go quite that far. I certainly don't anyway!

With sealed subs, ULF TR can be somewhat insidious. It may not be an extremely overt sensation, at the listening position, as it is with ported subwoofers, although there may be vibrations occurring in the room or elsewhere in the house. Instead, with sealed subs, there is usually just a gradual build-up of pressure (from the right SPL at the right frequencies) until we feel our ears start to tingle, and then the rest of the sensations I described. Room vibrations may also be occurring, especially on a suspended wood floor. With enough pressure, we can feel it in other parts of our bodies, as well. This is one of those YMMV issues. As noted, those sensations are not something I particularly care for.

What I do like is the sensation of ULF energy running throughout the whole room, even on a concrete floor. With low-tuned ported subs, playing the right frequencies at the right volume levels, that can be a very forceful and memorable sensation. In my room, I have described it as making the whole room ripple with ULF energy. And, it is not exactly the same sensation that you feel with your Crowson's, even as good as they are. It's not the sensation of you and your chair moving, as much as it is the sensation of energy (air particles creating particle velocity) moving within the room.

Brian Ding, of Rythmik, described the difference as similar to the sensation of having a baseball thrown close to our heads. We may hear the passage of the ball through the air, but we will also feel the energy of the air displacement occurring as the ball moves through the air. Brian went on to say that film mixers were well aware of the difference between sound and sensation and developed their low-frequency special effects in movies with that in mind.

I can't speak to that last part, but I can say that very low-frequency sounds, and the tactile sensations that accompany them, are not identical. They are hard for our brains to separate as two discrete events (as I think we can more easily with chest punch) but we are aware that both sound and sensation are occurring. I think it is especially difficult to separate <20Hz sounds and sensations, and yet in my opinion, that is where a lot of the real magic happens.

Thunder from a nearby lightening strike is a great natural example of ULF SPL and TR. We hear the peal of the thunder, and we feel the whole house vibrate from the massive displacement of air which accompanies it. I could try to add more detail to this part of the discussion, but I think I have made the point. If you haven't experienced the combination of ULF SPL and TR in your HT, you may not know what you are missing.

Part 2:

Now, let me try to talk about subwoofers a little. Yes, PB16's can theoretically pressurize a 6,500^3 room, as they can in my 6,000^3 room, although once again I would forget about the idea of room pressurization as a single specific goal, if I were you. There is a lot of ULF TR that can occur with ported subs, before room pressurization is achieved. Thank goodness, for those of us who don't enjoy cabin pressurization as much! (I have flown a lot, and done some scuba diving, and having my ear drums tingle and my ears stopped-up is not one of my all-time favorite sensations.)

I have the equivalent of four PB16's in my 6,000^3 room, on concrete. (Three PB16's and a PB4000 located 22" behind my listening chair.) My room is very heavily-constructed, which adds to the boundary reinforcement and mid-bass containment, and I can seal the room when I want to. Could I get quite as much bass into the low-teens, as I would like (the low-teens is really what I want for most movies) with only two PB16's? I'm not sure.

I already had four PB13's when the PB16's came out, so it was easy for me just to move-up a model, and later to replace my nearfield PB13 with a PB4000. As a side note, I not only get a great frequency response with four subs, and extra TR with a nearfield one, I also get great bass envelopment with the way my room is set-up.

It's possible that you will need to use the one-year SVS upgrade plan to move to PB16's, or that you will prefer to stay with SVS subs for other reasons. Personally, I really like the form factor, piano black finish, and digital controls and display. But, I was able to spread my expenditures and upgrades out over time, so I could afford to get four of what I wanted. If I were advising you, knowing what I do about your room, listening levels, and bass preferences, would I advise you to upgrade to dual PB16's? Once again, I'm not sure.

Leaving form/aesthetic/feature/ease of upgrade considerations completely out of the equation, I would advise you to buy dual Cap 2400ULF's. (As you may know, they have a 10Hz port tune, with a lot of DSP pushed into the lowest-frequencies.) They are more costly than the PB16's, and you would have to independently sell your PB3000's, but they are available in either a low version or a tall version. (The tall version can also just lay on its side.) There would be a considerable performance difference with those subs.

The PB16's would stay even with, or slightly better than, the Cap 2400 from about 30Hz down to about 14 or 15Hz. But, the Cap 2400 would be about 5dB more powerful in the mid-bass frequencies, and would absolutely smoke the PB16 below about 14Hz. In a 6500^3 room, where your pressure vessel gain (PVG is the strongest form of room gain) will start a fraction below 15Hz, I think that dual Cap 2400's would be a better solution for you than dual PB16's.

The new PSA TV3612's would also be a very good solution for you. Those are dual pro-audio 18" drivers, in a large cabinet volume, with a 13.5-14Hz port tune. They have a ton of mid-bass, and better low-frequency extension than the PB16's. They would be my second choice for your room, with the PB16's my third, based purely on SPL performance.

Sound signature and ULF TR are also considerations, though. And, these are somewhat subjective considerations, as are the observations which follow. The new PSA subs would have a slightly clearer sound signature and a more enveloping TR sensation, I think, compared to the Cap 2400's and the PB16's. The PSA subs might blend a little more with some content. The JTR subs would be more overt and violent, with the SVS subs a little more similar to JTR than to PSA. You really notice the <20Hz content, at high volume levels, when the JTR and SVS subs are playing.

I know that you said you had some work to do with your wife on this whole upgrade issue, which is still better than "She will kill me!" But, that is about the most objective answer to your questions that I can give you. I am lucky enough to be able to have just what I want right now, and it was pretty painless for me to get there. But, in trying to advise someone else, I need to leave aside my own situation and preferences, and just concentrate on performance factors.

If you need to stay with SVS, then a pair of PB16's may work perfectly well for you. But, I am much more certain that a pair of Cap 2400ULF's (or their slightly smaller 2400 siblings) will be able to energize your room with bass, and deliver the strong <20Hz SPL that you are lacking now. And, they will be able to do it with less compression and distortion.

The 15.5" driver, and lower amplifier power of the PB16, is just giving up a little too much for a full frequency response, head-to-head match-up, with the Cap 2400 in my opinion. It is possible to make-up most of the difference with additional PB16 multiples, but head-to-head, the advantage has to go to the JTR Cap 2400, and to the dual-driver PSA TV3612.

I hope this long post is helpful in clarifying some things that you and others may be curious about. If you want to understand more about room gain, or about some other things involving bass and subwoofers, additional explanations may be found in the Guide linked below.

Regards,
Mike

I think I'm locked in with SVS, I live an hour away from their offices and I can get a discount for driving there to do trade up. I also have the one year trade up and I'd really prefer not to deal with the hassle of selling the 3000s 3rd party. Otherwise I'd likely go with the Cap2400s. With the trade up I'm guaranteed full value. I can also get the dual discount.

Greatly appreciate all of this. I'd like it 10x if I could. I absolutely don't get the ULF SPL sensation of air moving around me with my current setup. THIS is what I want and is the rabbit in the hole I've been missing. I assumed that was pressurization. I am 10 feet from one sub and 13 from the other. If I can get a sensation of air movement going to the 16s then I'm all for it.

I think I'm making good progress with my wife (10 year contract to be done upgrading the sound lol).

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post #22 of 35 Old 01-15-2020, 03:52 PM - Thread Starter
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Originally Posted by mthomas47 View Post
Hi Matt,

First of all, you are very welcome for any help I have provided! Trying to answer all (or even some) of your questions will be quite an undertaking, but I will give it a shot.

Part 1:

Let's start with room pressurization. Room pressurization occurs when the air in the room literally becomes compressed, or condensed, due to air pressure. The sensation we feel is similar to that which we feel when an airplane cabin pressurizes. First, our ears start to tingle, and then our ear drums feel substantial pressure, and ultimately we may feel pressure in the head and face. I don't particularly like that sensation, but I have experienced it in my 6,000^3 room.

It is easiest to experience cabin pressurization in a sealed room, and smaller rooms can be pressurized more easily than large ones, partly due to room gain. Although I haven't attempted to measure the exact SPL (or frequency) at which room pressurization occurs in my room, I believe it happens with content in about the low to mid-teens, with about 115dB (or more) of volume at those frequencies. The thing about ported subs, though, is that we usually feel so much tactile ULF, before we feel cabin pressurization, that we never need to go quite that far. I certainly don't anyway!

With sealed subs, ULF TR can be somewhat insidious. It may not be an extremely overt sensation, at the listening position, as it is with ported subwoofers, although there may be vibrations occurring in the room or elsewhere in the house. Instead, with sealed subs, there is usually just a gradual build-up of pressure (from the right SPL at the right frequencies) until we feel our ears start to tingle, and then the rest of the sensations I described. Room vibrations may also be occurring, especially on a suspended wood floor. With enough pressure, we can feel it in other parts of our bodies, as well. This is one of those YMMV issues. As noted, those sensations are not something I particularly care for.

What I do like is the sensation of ULF energy running throughout the whole room, even on a concrete floor. With low-tuned ported subs, playing the right frequencies at the right volume levels, that can be a very forceful and memorable sensation. In my room, I have described it as making the whole room ripple with ULF energy. And, it is not exactly the same sensation that you feel with your Crowson's, even as good as they are. It's not the sensation of you and your chair moving, as much as it is the sensation of energy (air particles creating particle velocity) moving within the room.

Brian Ding, of Rythmik, described the difference as similar to the sensation of having a baseball thrown close to our heads. We may hear the passage of the ball through the air, but we will also feel the energy of the air displacement occurring as the ball moves through the air. Brian went on to say that film mixers were well aware of the difference between sound and sensation and developed their low-frequency special effects in movies with that in mind.

I can't speak to that last part, but I can say that very low-frequency sounds, and the tactile sensations that accompany them, are not identical. They are hard for our brains to separate as two discrete events (as I think we can more easily with chest punch) but we are aware that both sound and sensation are occurring. I think it is especially difficult to separate <20Hz sounds and sensations, and yet in my opinion, that is where a lot of the real magic happens.

Thunder from a nearby lightening strike is a great natural example of ULF SPL and TR. We hear the peal of the thunder, and we feel the whole house vibrate from the massive displacement of air which accompanies it. I could try to add more detail to this part of the discussion, but I think I have made the point. If you haven't experienced the combination of ULF SPL and TR in your HT, you may not know what you are missing.

Part 2:

Now, let me try to talk about subwoofers a little. Yes, PB16's can theoretically pressurize a 6,500^3 room, as they can in my 6,000^3 room, although once again I would forget about the idea of room pressurization as a single specific goal, if I were you. There is a lot of ULF TR that can occur with ported subs, before room pressurization is achieved. Thank goodness, for those of us who don't enjoy cabin pressurization as much! (I have flown a lot, and done some scuba diving, and having my ear drums tingle and my ears stopped-up is not one of my all-time favorite sensations.)

I have the equivalent of four PB16's in my 6,000^3 room, on concrete. (Three PB16's and a PB4000 located 22" behind my listening chair.) My room is very heavily-constructed, which adds to the boundary reinforcement and mid-bass containment, and I can seal the room when I want to. Could I get quite as much bass into the low-teens, as I would like (the low-teens is really what I want for most movies) with only two PB16's? I'm not sure.

I already had four PB13's when the PB16's came out, so it was easy for me just to move-up a model, and later to replace my nearfield PB13 with a PB4000. As a side note, I not only get a great frequency response with four subs, and extra TR with a nearfield one, I also get great bass envelopment with the way my room is set-up.

It's possible that you will need to use the one-year SVS upgrade plan to move to PB16's, or that you will prefer to stay with SVS subs for other reasons. Personally, I really like the form factor, piano black finish, and digital controls and display. But, I was able to spread my expenditures and upgrades out over time, so I could afford to get four of what I wanted. If I were advising you, knowing what I do about your room, listening levels, and bass preferences, would I advise you to upgrade to dual PB16's? Once again, I'm not sure.

Leaving form/aesthetic/feature/ease of upgrade considerations completely out of the equation, I would advise you to buy dual Cap 2400ULF's. (As you may know, they have a 10Hz port tune, with a lot of DSP pushed into the lowest-frequencies.) They are more costly than the PB16's, and you would have to independently sell your PB3000's, but they are available in either a low version or a tall version. (The tall version can also just lay on its side.) There would be a considerable performance difference with those subs.

The PB16's would stay even with, or slightly better than, the Cap 2400 from about 30Hz down to about 14 or 15Hz. But, the Cap 2400 would be about 5dB more powerful in the mid-bass frequencies, and would absolutely smoke the PB16 below about 14Hz. In a 6500^3 room, where your pressure vessel gain (PVG is the strongest form of room gain) will start a fraction below 15Hz, I think that dual Cap 2400's would be a better solution for you than dual PB16's.

The new PSA TV3612's would also be a very good solution for you. Those are dual pro-audio 18" drivers, in a large cabinet volume, with a 13.5-14Hz port tune. They have a ton of mid-bass, and better low-frequency extension than the PB16's. They would be my second choice for your room, with the PB16's my third, based purely on SPL performance.

Sound signature and ULF TR are also considerations, though. And, these are somewhat subjective considerations, as are the observations which follow. The new PSA subs would have a slightly clearer sound signature and a more enveloping TR sensation, I think, compared to the Cap 2400's and the PB16's. The PSA subs might blend a little more with some content. The JTR subs would be more overt and violent, with the SVS subs a little more similar to JTR than to PSA. You really notice the <20Hz content, at high volume levels, when the JTR and SVS subs are playing.

I know that you said you had some work to do with your wife on this whole upgrade issue, which is still better than "She will kill me!" But, that is about the most objective answer to your questions that I can give you. I am lucky enough to be able to have just what I want right now, and it was pretty painless for me to get there. But, in trying to advise someone else, I need to leave aside my own situation and preferences, and just concentrate on performance factors.

If you need to stay with SVS, then a pair of PB16's may work perfectly well for you. But, I am much more certain that a pair of Cap 2400ULF's (or their slightly smaller 2400 siblings) will be able to energize your room with bass, and deliver the strong <20Hz SPL that you are lacking now. And, they will be able to do it with less compression and distortion.

The 15.5" driver, and lower amplifier power of the PB16, is just giving up a little too much for a full frequency response, head-to-head match-up, with the Cap 2400 in my opinion. It is possible to make-up most of the difference with additional PB16 multiples, but head-to-head, the advantage has to go to the JTR Cap 2400, and to the dual-driver PSA TV3612.

I hope this long post is helpful in clarifying some things that you and others may be curious about. If you want to understand more about room gain, or about some other things involving bass and subwoofers, additional explanations may be found in the Guide linked below.

Regards,
Mike
So I presume you recommend running them in extended mode then?

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post #23 of 35 Old 01-16-2020, 08:10 AM
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Originally Posted by mthomas47 View Post
Hi Matt,

First of all, you are very welcome for any help I have provided! Trying to answer all (or even some) of your questions will be quite an undertaking, but I will give it a shot.

Regards,
Mike
I shortened the quoted lengthy post for brevity sake. But that was one hell of a response Mike. How do you continue to write such precise, comprehensive and relatable posts amazes me. Your unbiased neutrality stands as a Golden Beacon of Truth and honesty I wish we saw more of that around here.

Major Kudos Mike!

I do have a very small addition to your example of what room pressurization feels like. It happens in a Car. When you open one window a vary small amount, normally from the back seat. It can create a "thump", "thump", "thump" sensation on your ears. Also when you are in the Car and someone gets out and slams their door closed. That is a good example of "Room Pressurization" that we all have probably felt at on time or another.

Mike, keep a copy of your above Post. I suspect it may live to serve another life in a Guide of some type. If only someone would write one!!!!
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post #24 of 35 Old 01-16-2020, 11:06 AM - Thread Starter
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I shortened the quoted lengthy post for brevity sake. But that was one hell of a response Mike. How do you continue to write such precise, comprehensive and relatable posts amazes me. Your unbiased neutrality stands as a Golden Beacon of Truth and honesty I wish we saw more of that around here.

Major Kudos Mike!

I do have a very small addition to your example of what room pressurization feels like. It happens in a Car. When you open one window a vary small amount, normally from the back seat. It can create a "thump", "thump", "thump" sensation on your ears. Also when you are in the Car and someone gets out and slams their door closed. That is a good example of "Room Pressurization" that we all have probably felt at on time or another.

Mike, keep a copy of your above Post. I suspect it may live to serve another life in a Guide of some type. If only someone would write one!!!!
Well said.

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post #25 of 35 Old 01-16-2020, 01:13 PM
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Quote:
Originally Posted by Adamg (Ret-Navy) View Post
I shortened the quoted lengthy post for brevity sake. But that was one hell of a response Mike. How do you continue to write such precise, comprehensive and relatable posts amazes me. Your unbiased neutrality stands as a Golden Beacon of Truth and honesty I wish we saw more of that around here.

Major Kudos Mike!

I do have a very small addition to your example of what room pressurization feels like. It happens in a Car. When you open one window a vary small amount, normally from the back seat. It can create a "thump", "thump", "thump" sensation on your ears. Also when you are in the Car and someone gets out and slams their door closed. That is a good example of "Room Pressurization" that we all have probably felt at on time or another.

Mike, keep a copy of your above Post. I suspect it may live to serve another life in a Guide of some type. If only someone would write one!!!!

Thank you very much for the compliments, Adam! I really appreciate your supportive comments! Most of what I wrote is already in my Guide, in a much more spread-out form. But, the condensed version is much easier to read.

I also really like your car analogy, as a simple way to illustrate TR. I think I will steal it and use it sometime. They say that imitation is the sincerest form of flattery. Outright theft of an analogy would still be flattering, wouldn't it?

Regards,
Mike
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GUIDE TO SUBWOOFER CALIBRATION AND BASS PREFERENCES

* The Guide linked above is a comprehensive guide to Audio & HT systems, including:
Speaker placements & Room treatments; HT calibration & Room EQ; Room gain; Bass
Preferences; Subwoofer Buyer's Guide: Sealed/ported; ID subs; Subwoofer placement.
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post #26 of 35 Old 01-16-2020, 01:56 PM - Thread Starter
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Well its done, exchanging the 3ks for 16 ultras tomorrow!

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post #27 of 35 Old 01-16-2020, 02:44 PM
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Originally Posted by mthomas47 View Post

I also really like your car analogy, as a simple way to illustrate TR. I think I will steal it and use it sometime. They say that imitation is the sincerest form of flattery. Outright theft of an analogy would still be flattering, wouldn't it?

Regards,
Mike
Mike,

I would be honored if you did. Think that goes without saying.
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post #28 of 35 Old 01-18-2020, 04:45 PM - Thread Starter
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Originally Posted by mthomas47 View Post
Thank you very much for the compliments, Adam! I really appreciate your supportive comments! Most of what I wrote is already in my Guide, in a much more spread-out form. But, the condensed version is much easier to read.

I also really like your car analogy, as a simple way to illustrate TR. I think I will steal it and use it sometime. They say that imitation is the sincerest form of flattery. Outright theft of an analogy would still be flattering, wouldn't it?

Regards,
Mike
So I've had a chance now to do a few meaningful tests now with the PB16s.

The most meaningful one was testing Rogue One. This is because I had just watched it last weekend running at reference with BEQ and running 9db hot so it was fresh in my mind. Its an amazingly well mixed movie with prodigious LFE. Last weekend I thought it was great, extremely powerful bass. Well it turns out I didn't know what I was missing.

Again running at reference 9db hot with BEQ on I'll describe it like this, dynamic moments caused goosebumps, TR on the ottoman and legs that I had never experienced, my eyelids were literally twitching similar to one whose eyes have gone crossed out of their control, and several times I knee jerk blurted out gleeful hoots. While the previous weekend was impressive to me and surely anyone else not knowing what is possible, this was something else entirely. At dynamic moments there was a crescendo I didn't realize I was falling short of. I wouldn't say the effect for Rogue one at least was the 'baseball flying by your head' sensation level of TR. I don't know how hot you have to run and at what frequency would cause such a situation to arise. This was running in extended mode FWIW.

So, yeah it was worth it, Not an ounce of regret.

Another observation: This is totally subjective but I felt like my other speakers sounded better, they already sounded amazing but it seemed as though there was more accurate panning across the soundstage. Not sure if this is because the 3k's amps were tapped out and we had moved on to tapping out the AVR power causing general degredation in the system?? Or maybe the panning sounds had bass management that was getting compressed by the lack of juice so I was just missing out on the presense for those effects?

Whatever, thanks Mike for seducing me into upgrading. All the thumbs up!

Two more quick smash and grab questions:
1. Do you have ports angled at MLP such that they become small air conditioner units?
2. Do you ever find an advantage to running in standard mode?

Again, couldn't be happier I did this and thanks for all your valued commentary.

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post #29 of 35 Old 01-18-2020, 05:33 PM
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So, are you still running the cascading crossovers with the new subs?

Denon, Polk, Parasound, PSA
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post #30 of 35 Old 01-18-2020, 05:43 PM - Thread Starter
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So, are you still running the cascading crossovers with the new subs?
Yeah 90 hz. But I'm sure I will play around with the link confinoj pointed me to as well as default CC and 80, 100 etc. 90 sounds great to me right now but I never stop screwing around with stuff.

My room causes FR to drop like a rock past 90hz with both the 3ks and the 16s so I don't know if theres much point trying to defeat it with EQ. I'm assuming its the placement I'm using. Thing is this placement gives me the best response 60 and down so I'm sticking with it.

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