Plugging ports of vented subwoof SVS PB16 makes it "same" as sealed SB16? - AVS Forum | Home Theater Discussions And Reviews
Forum Jump: 
 12Likes
  • 2 Post By Bill Fitzmaurice
  • 2 Post By Bill Fitzmaurice
  • 1 Post By SoCalGuy-99
  • 1 Post By donktard
  • 1 Post By cannga
  • 2 Post By SoCalGuy-99
  • 2 Post By mthomas47
  • 1 Post By SoCalGuy-99
 
Thread Tools
post #1 of 23 Old 11-19-2016, 09:38 AM - Thread Starter
AVS Forum Special Member
 
cannga's Avatar
 
Join Date: Feb 2001
Location: Palos Verdes - Lakers Land
Posts: 3,422
Mentioned: 73 Post(s)
Tagged: 0 Thread(s)
Quoted: 1909 Post(s)
Liked: 1862
Plugging ports of vented subwoof SVS PB16 makes it "same" as sealed SB16?

Questions for the subwoofer experts here; sorry if this has been discussed before.

In a subwoofer that is designed from the start to be either ported or sealed such as the gorgeous new SVS PB16, does plugging all 3 ports make it measure/sound/behave, etc., more or less identical or very close to its sealed counterpart SVS SB16?

If so for those who would like to experiment and/or could not be sure how a subwoofer would behave once it's actually in the room, the PB 16 would seem to be a much better choice? Price and size notwithstanding. TIA

Regards, Can
My System & Theta Casablanca Mini-Review Uncontrolled passion for music, and sound.
Casablanca IVa Dirac Set Up Help HERE And some interesting audio diagrams.
JTR Subwoofer Thread I don't always listen to subwoofers, but when I do, it's JTR :-).

Last edited by cannga; 11-19-2016 at 09:42 AM.
cannga is offline  
Sponsored Links
Advertisement
 
post #2 of 23 Old 11-20-2016, 06:46 AM
Member
 
Orijen's Avatar
 
Join Date: Feb 2012
Posts: 176
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 85 Post(s)
Liked: 69
Ported = louder, deeper, "sloppy" Bass right? Or, this is how some have described a ported type box.








A friend of mine has the PB13 and listens to Cannibal Corpse and Lamb of God type death/speed metal... His PB13 keeps up at 6-10 kick drum beats a second "OPEN" and you can feel every one. I cant imagine this 16 not being able to do the same. When I play the same music through my SB13's, sounds the same as far as "clean" Bass..


There is no magical EAR that someone bought from the same guy that sold Jack his bean stalk (My cousin Vinny reference) as to what subs or speakers "should" sound like.. This sub with the ports closed should make it "tighter" but this will all depend on how YOU like your Bass... Take the 45 day in home trial, don't like it return it for the SB. Don't like that one return it
Orijen is offline  
post #3 of 23 Old 11-20-2016, 06:58 AM
AVS ***** Member
 
mthomas47's Avatar
 
Join Date: Nov 2007
Posts: 8,483
Mentioned: 378 Post(s)
Tagged: 0 Thread(s)
Quoted: 5653 Post(s)
Liked: 11215
Quote:
Originally Posted by cannga View Post
Questions for the subwoofer experts here; sorry if this has been discussed before.

In a subwoofer that is designed from the start to be either ported or sealed such as the gorgeous new SVS PB16, does plugging all 3 ports make it measure/sound/behave, etc., more or less identical or very close to its sealed counterpart SVS SB16?

If so for those who would like to experiment and/or could not be sure how a subwoofer would behave once it's actually in the room, the PB 16 would seem to be a much better choice? Price and size notwithstanding. TIA
It's an interesting question. Ported subs are typically much larger and are also more expensive than their sealed counterparts. That is true with the PB16, compared to the SB16. So, some people have questioned the desirability of maintaining the sealed option in the flagship SVS ported subs, as it does add to the price. But, that versatility is part of the SVS trademark.

From what I have read about the new PB16, it is an improvement over the PB13 (which wasn't too shabby) in this respect. The PB16, with all ports plugged, is supposed to be an almost exact match in sound quality to the SB16. So, for someone who wants to experiment at times with obtaining the SQ characteristics of a sealed sub, from a large ported sub, the PB16 may be a very good option. It is, apparently, even better in that respect than the PB13.

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.
mthomas47 is online now  
Sponsored Links
Advertisement
 
post #4 of 23 Old 11-20-2016, 07:10 AM
AVS Forum Addicted Member
 
basshead81's Avatar
 
Join Date: Mar 2013
Location: Fort Wayne, IN
Posts: 13,556
Mentioned: 200 Post(s)
Tagged: 0 Thread(s)
Quoted: 348 Post(s)
Liked: 10023
plugging all the ports to make it sealed. It does not make any sense to me. Basically you are defeating the ported sub's purpose of delivering 8-10db more output around tune....so now you have one massive box that is not doing any more then the much smaller SB16. If you want a sealed sub then get the SB16.
basshead81 is offline  
post #5 of 23 Old 11-20-2016, 07:10 AM
 
Bill Fitzmaurice's Avatar
 
Join Date: Nov 2009
Location: New Hampshire
Posts: 15,491
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 5778
Quote:
Originally Posted by cannga View Post
does plugging all 3 ports make it measure/sound/behave, etc., more or less identical or very close to its sealed counterpart SVS SB16?
If the box sizes are the same and the drivers are the same the result would be the same. They shouldn't be, as a ported cab would normally be larger than a sealed cab, and the drivers should have different specs. Only SVS can say for sure.
CoffeeHawk and audiofan1 like this.
Bill Fitzmaurice is offline  
post #6 of 23 Old 11-20-2016, 07:11 AM
Senior Member
 
CoffeeHawk's Avatar
 
Join Date: Aug 2004
Location: Austin, TX
Posts: 446
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 208 Post(s)
Liked: 115
What would an actual speaker engineer say?

Think about how much air is being pushed such that you can feel the bass.
For every action there is an equal and opposite action - the same amount of pressure being created in front of the cone is being created in back of the cone in a sealed speaker.

A ported cabinet allows the cone to move faster on the 'return stroke' (and prepare for the next note) whereas a sealed cabinet creates an air spring behind the cone - and how is all this moderated by the electronics that control the magnet (speed, duration, pause, etc.)?

How about the durability of the cone itself - speed vs. strength - how do they predict that based on sealed vs. not sealed? At 50 Hz. the speaker moves 50 to 100 million times a year.

No car maker would ever seal the engine's crankcase and no jet engine maker would ever port their jet engine.
CoffeeHawk is offline  
post #7 of 23 Old 11-20-2016, 07:53 AM
 
Bill Fitzmaurice's Avatar
 
Join Date: Nov 2009
Location: New Hampshire
Posts: 15,491
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 5778
Quote:
Originally Posted by CoffeeHawk View Post
A ported cabinet allows the cone to move faster on the 'return stroke'
That's not the case.
Quote:
the same amount of pressure being created in front of the cone is being created in back of the cone in a sealed speaker.
The same is true of a ported speaker. Logically a ported speaker would not have the same compression in the rear chamber as a sealed speaker. But as is very often the case with respect to audio this time logic is wrong.
basshead81 and audiofan1 like this.
Bill Fitzmaurice is offline  
post #8 of 23 Old 11-20-2016, 09:32 AM
AVS Forum Special Member
 
bigguyca's Avatar
 
Join Date: Oct 2007
Location: East Turkestan
Posts: 1,944
Mentioned: 38 Post(s)
Tagged: 0 Thread(s)
Quoted: 1239 Post(s)
Liked: 1049
Quote:
Originally Posted by CoffeeHawk View Post
What would an actual speaker engineer say?

Think about how much air is being pushed such that you can feel the bass.
For every action there is an equal and opposite action - the same amount of pressure being created in front of the cone is being created in back of the cone in a sealed speaker. (1)

A ported cabinet allows the cone to move faster on the 'return stroke' (2) (and prepare for the next note (3)) whereas a sealed cabinet creates an air spring behind the cone - and how is all this moderated by the electronics that control the magnet (speed, duration, pause, etc.)?

How about the durability of the cone itself - speed vs. strength - how do they predict that based on sealed vs. not sealed? At 50 Hz. the speaker moves 50 to 100 million times a year.

No car maker would ever seal the engine's crankcase and no jet engine maker would ever port their jet engine. (4)

You may want to consider the following:

(1) Because of the sealed speaker box the pressure on the box side of the driver cone is higher or lower than atmospheric pressure on the outside surface of the cone depending on the position of the cone. The smaller the box with no other changes the greater the rise (or fall) in pressure. This pressure differential causes harmonic distortion since effectively the cone is being driven by a non-linear force. The smaller the box the greater the distortion although it is likely at low enough levels that it doesn't have a significant effect on sound quality. As the size of the box falls, with no other changes, more power is required to drive the entire system at low frequencies due to the increased pressure. It's not obvious, at least to me, what happens to the pressure in the box with a ported system.

(2) In a ported system around resonance the excursion of the driver is greatly reduced vs. the excursion for a sealed system. This is the benefit of having a port. This reduced excursion means that the velocity of the cone is also reduced.

(3) This seems to imply some level of consciousness in the driver. It is difficult to understand how the driver "prepares" for anything.

(4) How does this statement relate to the design or performance of loudspeakers?

Bill Fitzmaurice, who posted above, is a loudspeaker designer.
bigguyca is online now  
post #9 of 23 Old 11-20-2016, 09:49 AM
AVS Forum Special Member
 
bigguyca's Avatar
 
Join Date: Oct 2007
Location: East Turkestan
Posts: 1,944
Mentioned: 38 Post(s)
Tagged: 0 Thread(s)
Quoted: 1239 Post(s)
Liked: 1049
Quote:
Originally Posted by basshead81 View Post
plugging all the ports to make it sealed. It does not make any sense to me. Basically you are defeating the ported sub's purpose of delivering 8-10db more output around tune....so now you have one massive box that is not doing any more then the much smaller SB16. If you want a sealed sub then get the SB16.

IF box size and added cost aren't a problem, and if the driver and electronics provide an excellent result in all of the port configurations then the option of plugging the ports seems a good one. My bias is to get a PB16 since I've had good experiences with ported speakers and I frankly I judge that a well designed ported speaker is better than a sealed unit. Likely I'd use the PB16 with one port blocked, however I also find that I've been wrong before. I really like the optionality that's provided with the PB16. I would certainly try the sealed configuration since I'm a hobbyist, and who knows, I might like it better.
bigguyca is online now  
post #10 of 23 Old 11-20-2016, 11:06 AM
AVS ***** Member
 
mthomas47's Avatar
 
Join Date: Nov 2007
Posts: 8,483
Mentioned: 378 Post(s)
Tagged: 0 Thread(s)
Quoted: 5653 Post(s)
Liked: 11215
Quote:
Originally Posted by basshead81 View Post
plugging all the ports to make it sealed. It does not make any sense to me. Basically you are defeating the ported sub's purpose of delivering 8-10db more output around tune....so now you have one massive box that is not doing any more then the much smaller SB16. If you want a sealed sub then get the SB16.
Quote:
Originally Posted by bigguyca View Post
IF box size and added cost aren't a problem, and if the driver and electronics provide an excellent result in all of the port configurations then the option of plugging the ports seems a good one. My bias is to get a PB16 since I've had good experiences with ported speakers and I frankly I judge that a well designed ported speaker is better than a sealed unit. Likely I'd use the PB16 with one port blocked, however I also find that I've been wrong before. I really like the optionality that's provided with the PB16. I would certainly try the sealed configuration since I'm a hobbyist, and who knows, I might like it better.
Both points of view seem entirely legitimate to me. After all, it's just a matter of how we choose to implement our entertainment preferences. Speaking from a completely personal point of view, I like having ported subs, and need them in my big room for movies. So, the option to operate in sealed mode is a neat feature that I have never used, and probably never will. But, my preferences aren't other peoples' preferences.

I can see someone, who uses his sub for music, wanting to experiment with the sealed mode just to see how much it changes the sound. Ed Mullen says it does. Taking off the front grille, and adding/removing port plugs is a bit of a pain, but being able to change the DSP settings easily, from the front, or with a remote, will simplify that aspect of things.

Every sub maker has a slightly different design philosophy. This is a trademark of SVS's higher-end subs. And, there is obviously room in the marketplace for this approach, at this price point.

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.
mthomas47 is online now  
post #11 of 23 Old 11-20-2016, 11:36 AM
Senior Member
 
SoCalGuy-99's Avatar
 
Join Date: Apr 2005
Posts: 370
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 178 Post(s)
Liked: 251
Quote:
Originally Posted by cannga View Post
Questions for the subwoofer experts here; In a subwoofer that is designed from the start to be either ported or sealed such as the gorgeous new SVS PB16, does plugging all 3 ports make it measure/sound/behave, etc., more or less identical or very close to its sealed counterpart SVS SB16?

If so for those who would like to experiment and/or could not be sure how a subwoofer would behave once it's actually in the room, the PB 16 would seem to be a much better choice? Price and size notwithstanding. TIA
You asked for the subwoofer experts to chime in and they have given a tutorial of subwoofer theory and operation, and that may be exactly what you were looking for. From a layman's perspective, the answer is Yes a ported SVS sub (PB16) operating in sealed mode will perform very close to its sealed counterpart (SB16).

We don't have data on the 16 Ultra line yet but we do have data on the 13 Ultra line, and the comparison will be very similar.

Attachment #1 (from data-base.com) is the max output of the PB13 operating in sealed mode verses the SB13, as we can see the outputs are similar, with the sealed PB13 having more output from 20hz to 50hz mostly due to the bigger box size of the PB13.

Next if we look at the 10hz-200hz frequency response of the PB13 in sealed mode vs the SB13 they are also very similar in nature and only really vary in output (see attachment #2 also from data-base.com).

Now for some on these forums, if anyone would sacrifice a single db of output on a subwoofer for any reason, this is a crime punishable my death or a life of shame and ridicule....but by using a sealed configuration it does reduce group delay and improve time domain behavior.

Below is a excerpt from Ed Mullen (Director - Technology and Customer Service of SVS) regarding this topic in 2013 from Sound and Vision:

http://www.soundandvision.com/conten...-relations-svs

"If we look at a sub like the SB13-Ultra, the phase response is quite benign, the roll-off slope is shallower, and there’s less phase rotation below the –3 dB point so there’s less group delay. Subjectively you get that stop-on-a-dime bass that enthusiasts describe as faster or tighter. We specifically designed the SB13-Ultra to have optimum group delay and time domain behavior. That doesn’t mean our bass-reflex subs are bad for music, because we do everything we can to maximize frequency response and bandwidth linearity [equality of maximum output at all frequencies], and to shift the phase rotation below the music bandwidth. With that said, if you plot the group delay and look at time domain behavior, you will see distinct ringing near the port tuning as compared to the sealed box."

See attachment # 3 (from data-bass.com) plotting the group delay of the PB13 in open port mode and sealed mode. As we see, the group delay for the PB13 in sealed mode is very similar to the SB13.

Once we do seal the PB13/PB16 and change the DSP setting, there will still be some differences in operation when compared to the SB13/SB16 because the drive topologies are different. The PB13/PB16 use a underhung driver while the SB13/SB16 use a overhung driver, which may exhibit different cone excursion and linearity at max output between the two configurations.

An overview is here at Audioholics.com http://www.audioholics.com/subwoofer-reviews/svs-pb16-ulta-and-sb16-ultra-subwoofer and illustrated at https://en.wikipedia.org/wiki/File:V...l_geometry.svg (attachment #4).

So at the end of the day if someone wanted "to experiment and/or one was not sure how a subwoofer would behave once it's actually in their room" and didn't want to order both versions (PB16/SB16) - Yes they could order the PB16 and configure it open mode and sealed mode (which is very similar to the SB16) - and then compare which is better for them in their room with their equipment, with their material and for their taste. And if they are not using room correction sw, they could readily switch back and forth between sealed and open port mode freely whenever they wanted to.

Because as shown, when you plug the ports and change the DSP settings, the sealed PB models test and sound very similar to the SB models.

Now regarding the nuances of overhung vs underhung, gap height vs coil height, operating in ported vs sealed boxes - we now return back to the experts
Attached Thumbnails
Click image for larger version

Name:	Max output PB13 Sealed VS SB13.png
Views:	155
Size:	48.5 KB
ID:	1780313   Click image for larger version

Name:	FR - PB13 Sealed Vs SB13.jpg
Views:	182
Size:	156.7 KB
ID:	1780321   Click image for larger version

Name:	Group Delay PB 13 all Modes.png
Views:	151
Size:	215.0 KB
ID:	1780329   Click image for larger version

Name:	Overhung vs Underhung Voicecoil.png
Views:	190
Size:	12.0 KB
ID:	1780337  
mthomas47 likes this.

SCG

Last edited by SoCalGuy-99; 11-21-2016 at 11:33 AM.
SoCalGuy-99 is offline  
post #12 of 23 Old 11-20-2016, 11:44 AM
Member
 
Orijen's Avatar
 
Join Date: Feb 2012
Posts: 176
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 85 Post(s)
Liked: 69
Quote:
Originally Posted by bigguyca View Post
(4) How does this statement relate to the design or performance of loudspeakers?
.




I believe he's referring to the fact that if you seal a engine crank case (no breather) it creates a vacuum and decreases horsepower. Jet engine's push the thrust out one hole....


Could be a conundrum .. Like they say in the car business, there's a Butt for every seat... SVS supplies the seats and the Butt's BUY them...
Orijen is offline  
post #13 of 23 Old 11-20-2016, 12:20 PM
AVS Forum Special Member
 
Join Date: Sep 2015
Location: Europe, Croatia
Posts: 1,746
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 1012 Post(s)
Liked: 562
Well, if plugging holes isn't enough and you really want SB16 performance from PB16, you simply need to make internal volume of PB16 equal to SB16. Pour some cement in through the ports.

P.S. Don't pour cement in through the ports.
Alan P likes this.

Revel Ultima Salon 2, Revel M106, Revel C208, Yamaha P5000S, Denon X5200, Panasonic 65" VT50, Dual VBSS w Faital 18FH510
Kef LS50, Parasound New Classic, Focusrite 2i4 2nd Gen
donktard is offline  
post #14 of 23 Old 11-20-2016, 03:39 PM
Senior Member
 
CoffeeHawk's Avatar
 
Join Date: Aug 2004
Location: Austin, TX
Posts: 446
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 208 Post(s)
Liked: 115
Quote:
Originally Posted by Bill Fitzmaurice View Post
That's not the case.
The same is true of a ported speaker. Logically a ported speaker would not have the same compression in the rear chamber as a sealed speaker. But as is very often the case with respect to audio this time logic is wrong.
I'd to sort out a couple of details on what's been said. Are you agreeable to a private message discussion?
CoffeeHawk is offline  
post #15 of 23 Old 11-20-2016, 04:06 PM
Senior Member
 
CoffeeHawk's Avatar
 
Join Date: Aug 2004
Location: Austin, TX
Posts: 446
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 208 Post(s)
Liked: 115
Quote:
Originally Posted by bigguyca View Post
You may want to consider the following:

(1) Because of the sealed speaker box the pressure on the box side of the driver cone is higher or lower than atmospheric pressure on the outside surface of the cone depending on the position of the cone. The smaller the box with no other changes the greater the rise (or fall) in pressure. This pressure differential causes harmonic distortion since effectively the cone is being driven by a non-linear force. The smaller the box the greater the distortion although it is likely at low enough levels that it doesn't have a significant effect on sound quality. As the size of the box falls, with no other changes, more power is required to drive the entire system at low frequencies due to the increased pressure. It's not obvious, at least to me, what happens to the pressure in the box with a ported system.

(2) In a ported system around resonance the excursion of the driver is greatly reduced vs. the excursion for a sealed system. This is the benefit of having a port. This reduced excursion means that the velocity of the cone is also reduced.

(3) This seems to imply some level of consciousness in the driver. It is difficult to understand how the driver "prepares" for anything.

(4) How does this statement relate to the design or performance of loudspeakers?

Bill Fitzmaurice, who posted above, is a loudspeaker designer.
Scroll about half way down to see the influence of cabinet size and ports/vents. It's not trivial. http://www.ht-audio.com/pages/SpeakerBasics.html

The point being you wouldn't want to plug up ports any more than you would drill holes in cabinets, especially not on high end speakers.
CoffeeHawk is offline  
post #16 of 23 Old 11-20-2016, 04:15 PM
AVS Forum Special Member
 
Join Date: Sep 2015
Location: Europe, Croatia
Posts: 1,746
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 1012 Post(s)
Liked: 562
Quote:
Originally Posted by CoffeeHawk View Post
The point being you wouldn't want to plug up ports any more than you would drill holes in cabinets, especially not on high end speakers.
In case you don't know/realize, you actually get port plugs with all SVS ported subs and you can also set port tune on SVS control panel depending on amount of ports you plugged.

Revel Ultima Salon 2, Revel M106, Revel C208, Yamaha P5000S, Denon X5200, Panasonic 65" VT50, Dual VBSS w Faital 18FH510
Kef LS50, Parasound New Classic, Focusrite 2i4 2nd Gen
donktard is offline  
post #17 of 23 Old 11-20-2016, 04:20 PM
AVS Forum Special Member
 
golfster's Avatar
 
Join Date: Oct 2005
Location: St Louis, MO
Posts: 1,933
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 798 Post(s)
Liked: 672
Quote:
Originally Posted by cannga View Post

In a subwoofer that is designed from the start to be either ported or sealed such as the gorgeous new SVS PB16, does plugging all 3 ports make it measure/sound/behave, etc., more or less identical or very close to its sealed counterpart SVS SB16?
It would only behave the same if they both used the same driver or one that has the same T/S parameters. Boxes are designed around the driver and some drivers are better suited for a ported or AS box.
golfster is offline  
post #18 of 23 Old 11-20-2016, 05:35 PM
AVS Forum Special Member
 
Join Date: Jan 2015
Location: United States
Posts: 2,623
Mentioned: 56 Post(s)
Tagged: 0 Thread(s)
Quoted: 1314 Post(s)
Liked: 2164
I just "sealed" my garage subs

Not for any audio reason, the 6" diameter ports make a nice walkway for critters to setup light housekeeping in my subs. For the winter, I run sealed for protection.

Modeled my subs to run sealed or ported, rather entertaining to watch the curves move around when figuring out the correct enclosure size. If you make a ported box then plug it up VS making a smaller sealed box--two things happen. An "oversized" sealed box will roll off at a lower frequency generally but you'll lose some power handling from the increased stroke.

It goes alone the line of an infinite baffle, those subs can go low but they can't handle much power before hitting Xmax.

Does it matter? Well, that depends.
18Hurts is online now  
post #19 of 23 Old 11-21-2016, 08:29 AM
Senior Member
 
CoffeeHawk's Avatar
 
Join Date: Aug 2004
Location: Austin, TX
Posts: 446
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 208 Post(s)
Liked: 115
Quote:
Originally Posted by donktard View Post
In case you don't know/realize, you actually get port plugs with all SVS ported subs and you can also set port tune on SVS control panel depending on amount of ports you plugged.
I did not, thank you.

Time for me to leave this thread, but I yell defiantly as I leave that using foam plugs is not the same as literally plugging up a ported speaker!
CoffeeHawk is offline  
post #20 of 23 Old 11-21-2016, 10:00 AM - Thread Starter
AVS Forum Special Member
 
cannga's Avatar
 
Join Date: Feb 2001
Location: Palos Verdes - Lakers Land
Posts: 3,422
Mentioned: 73 Post(s)
Tagged: 0 Thread(s)
Quoted: 1909 Post(s)
Liked: 1862
Quote:
Originally Posted by SoCalGuy-99 View Post
Once we do seal the PB13/PB16 and change the DSP setting, there will still be some differences in operation when compared to the SB13/SB16 because the drive topologies are different. The PB13/PB16 use a underhung driver while the SB13/SB16 use a overhung driver, which may exhibit different cone excursion and linearity at max output between the two configurations.

An overview is here at Audioholics.com http://www.audioholics.com/subwoofer-reviews/svs-pb16-ulta-and-sb16-ultra-subwoofer and illustrated at https://en.wikipedia.org/wiki/File:V...l_geometry.svg (and attachment #4).

So at the end of the day if someone wanted "to experiment and/or one was not sure how a subwoofer would behave once it's actually in their room" and didn't want to order both versions (PB16/SB16) - Yes they could order the PB16 and configure it open mode and sealed mode (which is very similar to the SB16) - and then compare which is better for them in their room with their equipment, with their material and for their taste. And if they are not using room correction sw, they could readily switch back and forth between sealed and open port mode freely whenever they wanted to.

Because as shown, when you plug the ports and change the DSP settings, the sealed PB models test very similar to the SB models.
....
Thanks everyone for the very helpful replies and interesting "debate." I appreciate now the importance of size of cabinet and that the drivers are actually not the same between SVS ported and equivalent sealed models.

In retrospect, my question is not whether the PB 16 will behave exactly like the SB 16, but whether the PB 16 once ports are plugged and DSP settings changed, will behave/measure/sound like or reasonably like a sealed subwoofer. To that end it seems the answer is yes and looking at the detailed answer above, it seems I am not the only "sweating the details" on this issue.

For me, the PB16 is extremely tempting because I like to experiment, and don't want the mistake of ordering the "wrong" type (I personally prefer sealed subwoofer for 2 channel music and ported for movies) but goodness, the size and weight are *overwhelming*. The kids are gone to college and moving this thing up to second floor is nearly prohibitive by myself - would need labor help for sure.
mthomas47 likes this.

Regards, Can
My System & Theta Casablanca Mini-Review Uncontrolled passion for music, and sound.
Casablanca IVa Dirac Set Up Help HERE And some interesting audio diagrams.
JTR Subwoofer Thread I don't always listen to subwoofers, but when I do, it's JTR :-).

Last edited by cannga; 11-21-2016 at 10:21 AM.
cannga is offline  
post #21 of 23 Old 11-21-2016, 11:15 AM
Senior Member
 
SoCalGuy-99's Avatar
 
Join Date: Apr 2005
Posts: 370
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 178 Post(s)
Liked: 251
Quote:
Originally Posted by donktard View Post
...you actually get port plugs with all SVS ported subs and you can also set port tune on SVS control panel depending on amount of ports you plugged.
Quote:
Originally Posted by cannga View Post
For me, the PB16 is extremely tempting because I like to experiment, and don't want the mistake of ordering the "wrong" type (I personally prefer sealed subwoofer for 2 channel music and ported for movies) but goodness, the size and weight are *overwhelming*. The kids are gone to college and moving this thing up to second floor is nearly prohibitive by myself - would need labor help for sure.
If you have the cash and the space you can't go wrong with the PB16 (as donktard mentioned it comes with the plugs and the DSP settings) so it's designed by SVS to run in both ported and sealed mode, thus giving you the best of both worlds if you like sealed for music and ported for movies (like I do). The only real trade off is what you mentioned about the "overwhelming" size and weight of the PB16 - it's a big beautiful heavy beast, that takes 2 to install, but there are quite a few other subs on this forum that are a lot bigger and heavier.

Riztnack has two installed, as does Gene4ht, I have 2 on order, and Mthomas47 has 3 on order - so if you order one - welcome to the club, and remember labor's Not included, unless you do it while the kids are on college break





Pics by Riztnack, Imagic and Gene4hz
mthomas47 and joseph10704 like this.

SCG

Last edited by SoCalGuy-99; 11-22-2016 at 10:40 AM.
SoCalGuy-99 is offline  
post #22 of 23 Old 11-21-2016, 04:35 PM
AVS ***** Member
 
mthomas47's Avatar
 
Join Date: Nov 2007
Posts: 8,483
Mentioned: 378 Post(s)
Tagged: 0 Thread(s)
Quoted: 5653 Post(s)
Liked: 11215
Quote:
Originally Posted by CoffeeHawk View Post
I did not, thank you.

Time for me to leave this thread, but I yell defiantly as I leave that using foam plugs is not the same as literally plugging up a ported speaker!
A lot of that going around lately!

I wouldn't just arbitrarily start plugging up ports on a subwoofer, expecting to get good results, either. But, the upper tier of SVS subs are specifically designed to operate optimally with one port plugged, and the provided foam plugs work fine for that. Data-Bass, among others, has thoroughly tested the older flagship PB13 Ultra that way.

But, part of SVS's trademark is versatility in operation. So, even though the more expensive ported models are really designed for optimal performance (low extension, vis-a-vis SPL) with the one port plugged, and concomitant DSP adjustment, they still like to provide options for individual users who prefer other operating modes. And, as this thread and others demonstrate, some people do really appreciate and take advantage of that flexibility.

There is no doubt that the flexibility adds to the cost of the higher-end SVS subs, compared to subs such as the Cap 1400, which have only one tuning mode. But, again, that is part of the SVS brand, and they have the sales volume to demonstrate the strength and durability of that business model. And, they have plenty of professional and user reviews to demonstrate the inherent performance quality of the subs with variable port tunes. Just thought you'd like to know.

Regards,
Mike
SoCalGuy-99 and CoffeeHawk like this.

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.
mthomas47 is online now  
post #23 of 23 Old 11-22-2016, 10:49 AM
Senior Member
 
SoCalGuy-99's Avatar
 
Join Date: Apr 2005
Posts: 370
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 178 Post(s)
Liked: 251
Quote:
Originally Posted by mthomas47 View Post
I wouldn't just arbitrarily start plugging up ports on a subwoofer, expecting to get good results, either. But, the upper tier of SVS subs are specifically designed to operate optimally with one port plugged, and the provided foam plugs work fine for that. Data-Bass, among others, has thoroughly tested the older flagship PB13 Ultra that way. ...concomitant DSP adjustment...
Well said, and I would add that they are optimize for all ports plugged also, as tested by data-bass.com - nice use of the word concomitant
mthomas47 likes this.

SCG

Last edited by SoCalGuy-99; 11-22-2016 at 04:02 PM.
SoCalGuy-99 is offline  
Sponsored Links
Advertisement
 
Reply Subwoofers, Bass, and Transducers

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off