PL-89 tower speakers & Klipsch RB-81 II bookshelfs as sealed

johnny45

johnny45

Audioholic
would pluging the ports on my pair of PL-89 tower speakers an the ports on my Klipsch RB-81 II
with some custom cut thick rubber to sort of make them sealed be ok or would it completly suck im feeding each of them 200watts from a xli 800 ?
iv got a parometric eq to use for room correction
 
S

shadyJ

Speaker of the House
Staff member
would pluging the ports on my pair of PL-89 tower speakers an the ports on my Klipsch RB-81 II
with some custom cut thick rubber to sort of make them sealed be ok or would it completly suck im feeding each of them 200watts from a xli 800 ?
iv got a parometric eq to use for room correction
Why would you want to seal the ports? Do you hate bass? The ports are going to be what's creating most of the bass below 70 or 80 Hz on those things.
 
johnny45

johnny45

Audioholic
That I did not know
I was just wondering if like sealed subwoofers some times have or get a tighter bass response an sometimes better power handling, I was just wondering after seeing Hsu and svs subwoofers that have those big rubber plugs for the ports for opinional port configuration from fully ported to semi-ported to fully sealed I just wondered if I could or would get a better or more optimal response
 
S

shadyJ

Speaker of the House
Staff member
That I did not know
I was just wondering if like sealed subwoofers some times have or get a tighter bass response an sometimes better power handling, I was just wondering after seeing Hsu and svs subwoofers that have those big rubber plugs for the ports for opinional port configuration from fully ported to semi-ported to fully sealed I just wondered if I could or would get a better or more optimal response
The 'tightness' of sealed subs is largely a myth. Ported subs get a bad wrap from really crappy band-pass designs that often came with home-theater-in-a-box type systems. So some sub manufacturers supply ways of sealing ports. Sometimes port output can combine with room gain to really boost deep bass output, and that can make for a boomy sound in a small room, so in that situation, it might be worth sealing the ports. Other than that, subwoofer ports are usually tuned too low for port phase rotation to make an audible difference.

You could seal the ports on your speakers to give it a try, if only as an experiment. All you have to do is create an airtight seal. The result would simply be reduced low-frequency extension and output.
 
KEW

KEW

Audioholic Overlord
would pluging the ports on my pair of PL-89 tower speakers an the ports on my Klipsch RB-81 II
with some custom cut thick rubber to sort of make them sealed be ok or would it completly suck im feeding each of them 200watts from a xli 800 ?
iv got a parometric eq to use for room correction
It never hurts to try it!
Often a pair of socks can be stuffed effectively in a port for a quick and easy test.
With one of the older poorly designed subs, you were more likely to notice a positive difference.
Aside from a poorly designed port (where the tuned note of the port is unreasonably dominant), I believe you are essentially reducing the bass similar to the effect you could get from using your parametric EQ. One effect of reducing the ratio of bass to mids and highs (per Josh Ricci) is a perceived added tightness (tightness defined as reducing the overhang of low notes). So you can look at it as finding your optimal point between sufficient bass and proper "tightness".
Of course plugging ports is a on/off switch, where you would ideally want a continuously variable knob, but it may give you a sense of whether you would like to tweak your PEQ.

Also note that if you have subwoofers, but do not have an AVR that would apply a high-pass filter to your speakers, plugging the ports is a fairly effective way to get much of the benefit of high passing the speaker!
 
J

Jerkface

Audioholic
The important thing to remember about sealed vs. ported designs is exactly that - it was designed that way. You start trying to seal a ported unit or putting a port in a sealed unit, you're going to compromise the integrity of the original speaker design. Check down in the DIY forum where people roll their own speaker cabs, they'll tell you, every decision made in a speaker design is deliberate, and one cannot just go changing things without screwing up that design.

It's rather like replacing the stock woofer in your speaker with a Rat Shack replacement driver. You have no idea what it's going to do, because it was never meant to be there.
 
KEW

KEW

Audioholic Overlord
The important thing to remember about sealed vs. ported designs is exactly that - it was designed that way. You start trying to seal a ported unit or putting a port in a sealed unit, you're going to compromise the integrity of the original speaker design. Check down in the DIY forum where people roll their own speaker cabs, they'll tell you, every decision made in a speaker design is deliberate, and one cannot just go changing things without screwing up that design.

It's rather like replacing the stock woofer in your speaker with a Rat Shack replacement driver. You have no idea what it's going to do, because it was never meant to be there.
I would never put a port in a sealed speaker; however plugging ports is not such an obvious faux-pas as you present it to be!
There are several speakers that come with plugs for the ports including the JBL Studio 5 series (to name a major brand with significant research/science/competence behind their designs)!
It is especially beneficial if you end up having to place a speaker close to a wall or in a corner!
 
J

Jerkface

Audioholic
I would never put a port in a sealed speaker; however plugging ports is not such an obvious faux-pas as you present it to be!
There are several speakers that come with plugs for the ports including the JBL Studio 5 series (to name a major brand with significant research/science/competence behind their designs)!
It is especially beneficial if you end up having to place a speaker close to a wall or in a corner!
Fair. Though I would point out that JBL obviously designed the speaker to have that flexibility.

I guess the point I'm trying to make here is that just stuffing a port for the heck of it, without any clear purpose or outcome in mind, isn't a smart idea.

There are a thousand other ways one can "tighten up" the bass response in a room before they start plugging ports on speakers.
 
KEW

KEW

Audioholic Overlord
Fair. Though I would point out that JBL obviously designed the speaker to have that flexibility.

I guess the point I'm trying to make here is that just stuffing a port for the heck of it, without any clear purpose or outcome in mind, isn't a smart idea.

There are a thousand other ways one can "tighten up" the bass response in a room before they start plugging ports on speakers.
We'll have to agree to dis agree on this one.
Plugging a port may not get you the sound improvement you are looking for, but one of my main points is their is no harm in trying it. If the sound is not improved, remove the plug and no harm done (as opposed to porting a dedicated sealed design, which would likely overextend/destroy the driver at the tuned frequency)!
I'm sure Erin Hardin knows way more about speakers than both of us put together and plugging the port was his "go to" for improving these speakers (which did not provide plugs)!
Check 13 minutes and 45 seconds in this review:
 
Last edited:
S

shadyJ

Speaker of the House
Staff member
There are some who feel there is an advantage to having the ports sealed for integration with subs....like Barry O here https://soundoctor.com/whitepapers/subs.htm
While I'll be damned if I am going to read that wall of text, there is an advantage for subwoofer integration with sealing the main speakers (so long as sealing the ports doesn't reduce extension or bass output enough to matter). There is an inherent phase rotation in port output that can make it difficult to get perfect timing in crossing over to a subwoofer. Sealing the port smooths out the phase rotation since only the front side of the driver is producing output at that point. There are a lot of other factors in play here, but if you are having trouble getting the speakers to blend well with the sub, it might be worth a try to seal the speaker's ports.
 
KEW

KEW

Audioholic Overlord
There are some who feel there is an advantage to having the ports sealed for integration with subs....like Barry O here https://soundoctor.com/whitepapers/subs.htm
Agreed.
The bold below is why I felt compelled to respond to JF's post:
The important thing to remember about sealed vs. ported designs is exactly that - it was designed that way. You start trying to seal a ported unit or putting a port in a sealed unit, you're going to compromise the integrity of the original speaker design. Check down in the DIY forum where people roll their own speaker cabs, they'll tell you, every decision made in a speaker design is deliberate, and one cannot just go changing things without screwing up that design.

It's rather like replacing the stock woofer in your speaker with a Rat Shack replacement driver. You have no idea what it's going to do, because it was never meant to be there.
To me "compromise the integrity" means to do damage!
 
J

Jerkface

Audioholic
To me "compromise the integrity" means to do damage!
OK, so the language may have been a touch bombastic. Obviously stuffing a port with a pair of socks isn't likely to destroy your speaker. But it certainly can disrupt phase characteristics within the cabinet, making it sound like crap. When OP started talking about custom rubber plugs, I was like, "Hold up, let's not start throwing money at something that may not even be a problem here..."
 
lovinthehd

lovinthehd

Audioholic Jedi
Agreed.
The bold below is why I felt compelled to respond to JF's post:

To me "compromise the integrity" means to do damage!
Well you can get the port plugs from others too. Got them for my Ascend Sierra1s. Think my SVS came with them. My Studio 5 series did. I cross high enough I've not bothered using them, tho.
 
Kingnoob

Kingnoob

Audioholic Samurai
The important thing to remember about sealed vs. ported designs is exactly that - it was designed that way. You start trying to seal a ported unit or putting a port in a sealed unit, you're going to compromise the integrity of the original speaker design. Check down in the DIY forum where people roll their own speaker cabs, they'll tell you, every decision made in a speaker design is deliberate, and one cannot just go changing things without screwing up that design.

It's rather like replacing the stock woofer in your speaker with a Rat Shack replacement driver. You have no idea what it's going to do, because it was never meant to be there.
Yeah can’t port a sealed speaker unless volume is large enough for proper tuning , sealing a ported tower may ruin it ... and overdriving it could blow a woofer while sealed .
Sealed subs aren’t better then ported , just poorly designed subs suck , sealed or typically ported .
 
johnny45

johnny45

Audioholic
the reason im considering this is i did run rew once unplugged of course an the response that rew got showed the room correction need more peq adjustments then my outlaw audio 976 4k receiver had or could do especially when the option to set the software to match my 10 band parametric eq to get the necessary values that mine could do, so getting it to show the necessary room corrections base on my eq was not doable so i did the best to improvise to smooth out the bass but it was just recently while watching a video on subs with plug for port option configs like hsu an svs i thought made plugging my ports might help

that said what would you suggest to test with a big wad of cotton or some waded socks
 
Pogre

Pogre

Audioholic Slumlord
the reason im considering this is i did run rew once unplugged of course an the response that rew got showed the room correction need more peq adjustments then my outlaw audio 976 4k receiver had or could do especially when the option to set the software to match my 10 band parametric eq to get the necessary values that mine could do, so getting it to show the necessary room corrections base on my eq was not doable so i did the best to improvise to smooth out the bass but it was just recently while watching a video on subs with plug for port option configs like hsu an svs i thought made plugging my ports might help

that said what would you suggest to test with a big wad of cotton or some waded socks
You can use anything that stops the airflow. Some wadded up socks should work just fine. Or an old shirt, towel... whatever. It's not so much what the "plug" is made of as it is just stopping air movement through the port.
 
lovinthehd

lovinthehd

Audioholic Jedi
Y
You can use anything that stops the airflow. Some wadded up socks should work just fine. Or an old shirt, towel... whatever. It's not so much what the "plug" is made of as it is just stopping air movement through the port.
Yep, port plugs supplied generally are not rubber plugs that literally seal but rather open cell foam plugs....
 
johnny45

johnny45

Audioholic
update its been a little over 2 months since i plug my bic's ports i went with some spare lux foam custion materil

in the result is damn good at least to my ear the bass is still very present an i fell ,an i hate using the terms TIGHT AN SNAPY an other words detailed more then before
an at high volumes no distortion as before ref v -10db currently powered off my crown xls 1502 with the highpass at 42hz
at from the outlaw receiver per channel using its highpass shelf set at also 42hz at -6db with a bass boost at 50hz at +3db at q 1 at an 120hz +1.5db at q .5

now its deeper an tighter then before it was plugged iv yet to run rew to compare before an after but to my ear is good

with an without the eq settings when unplugged i could tell the bass was not as sharp a good exmple is the show seal team i was 1 season in an that show has so great battle sences with good dynamics but based on the screen while watching its seemed like with an without the eq settings when unplugged some up the explosions that appered they should sound separate on screen seemed blended togather as if one boom merged into the other

after plugging wow i was missing detail !!!!!

the battlefield 2042 trailer i watched 7 times it sound that good

i decided not to plug the Klipsch RB-81 port (currently as my center)

im thinking about upgrading to the CCB-8 Bookshelf Speaker as aloso for all my surrounds

thoughts
 
newsletter

  • RBHsound.com
  • BlueJeansCable.com
  • SVS Sound Subwoofers
  • Experience the Martin Logan Montis
Top