Ported vs Sealed Speaker Box
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- Опубликовано: 27 июн 2019
- Closed vs ported speaker box
If you are designing a speaker for the ultimate music experience, you are likely to stand at this crossroad. So, this video is about making a choice between the 2 systems.
First let me introduce the two contestants
In the red corner
The closed speaker box aka sealed enclosure. Its descriptive of what it is, a box or cabinet essentially as airtight as possible, where there is holes cut-out for the speaker drivers, and then with those mounted the box is sealed. This provide a very quick response of the speaker driver and a lot of audiophiles really likes this type of system.
In the blue corner
The ported speaker box, aka vented speaker box, is typically using a piece of pipe out of plastic or thick cardboard called a port. The port serves to assist the speaker box to resonate at a lower frequency with less movement of the speaker driver. This helps the speaker driver to lower and more powerful bass. But it comes at the price of a slower response because the pressure must build up in the box, before it can generate the resonance through the port. This is called time smearing because the impulses of the bass will start to overlap more.
But like any drama it’s never that simple and the likely hero might have dirty secrets and can be abusive to certain types of woofers.
And this is certainly the case for woofers. They themselves have personalities because of the way they are build. So, an 8” inch woofer is not just an 8” woofer.
The traits and personalities of speaker drivers are mechanical and electrical, and 2 guys where able to map this out and named a list of data by the name of Thiele-Small parameters. Here is an example:
Impedance (Z) 8 Ω
Resonant frequency (fs) 38 Hz
Max. frequency range f3-5,000 Hz
Music power 80 WMAX
Power rating (P) 50 WRMS
SPL (1 W/m) 90 dB
Suspension compl. (Cms) 1.43 mm/N
Moving mass (Mms) 12.5 g
Mech. Q factor (Qms) 2.38
Electr. Q factor (Qes) 0.55
Total Q factor (Qts) 0.44
Equivalent volume (Vas) 37 l
DC resistance (Re) 6.2 Ω
Force factor (BxL) 5.9 Tm
Voice coil induct. (Le) 0.45 mH
Voice coil diameter 25 mm
Voice coil former aluminium
Linear excursion (XMAX) ±3mm
Eff. cone area (Sd) 137cm2
With these parameters you can calculate a likely good outcome for your woofer.
But let’s not get to far out on the deep end, and go right after getting the essential question answered, sealed or vented?
An excellent way is by calculating the EBP value, with stands for Efficiency bandwidth product.
This number is generated by finding where the woofer is resonating in Hz (hertz) and divide by how much electrically the woofer is resonating.
The point where a woofer is resonating by itself, is called the free air resonance frequency or just resonance frequency. In the Thiele-small parameters it will be called fs, and again measured in Hz.
How much the woofer is resonating electrically is named Qes. The higher this number is the more its resonating, and the electrical resonance is far more dominant than the mechanical.
This gives us a very simple formula EBP = fs / Qes
So, let’s say you already have a speaker driver like the one showed earlier in the description.
We find fs to be 38Hz and Qes to be 0,55.
38 / 0,55 = 69
What does an EBP of 69 mean?
The EBP has a scale in which the ideal boxes are represented.
50 is ideal for a closed speaker box
90 is ideal for a ported speaker box
So 69 is right down the middle so can choose either system and choose what you like the best, closed for best impulse response or ported for extended more powerful bass.
If the EBP was let’s say 58 so likely success with closed speaker box, and here again in uncooperative manner are choosing a ported box are you likely to get a muddy and unclear bass response.
In conclusion
One system is not better than the other, and it’s important to calculate the right box for a given speaker driver or to find the right speaker driver for your box in order to get a nice bass response.
As a heads up for you that wants to replace your woofers in your speakers because you cooked them at the last party with some Hypertraxx music, or other situations that lead to this search for woofers. Think about this aspect and perhaps you can initially use the EBP value to filter the useable from the unusable woofers. But there is more to picking a woofer that will work in an existing speaker, but that’s going to be another video.
A dedicated website to our speaker repair and service with more detailed information is currently in the works - keep an eye on audiovega.com/. I specialize in refoaming a diverse range of brands, having a wealth of experience with JBL, Cerwin Vega, Snell, Dali, Bang and Olufsen, and Scan-speak drivers. My proficiency particularly lies in refurbishing and upgrading crossovers, as well as carrying out driver replacements and upgrades that often necessitate precise measurements and calculations. Trust that your audio equipment is in capable hands.
Kind regards
Kent Larsen 
Хобби
listen the video with 1.25 x speed
much better lol
I actually thought he recorded at 1.25 and slowed it down to 1
1.5x 😎
I did this
I'm with you 💯😂
You helped me a lot with this video. My current project is a vented enclosure, but the next one will be a sealed box.
Good call, they general provide so much detail and nuance, but I still like the deep rolls from the ported.
Well explained! Thank you.
Thank you so much for sharing.
Amazing. Very useful, loving the vids. Keep it up!
Thank you Chris! I am motivated for more now!
Extremely useful vid! Thanks 👍😀
absolutely incredible video
Thank you for that information. It was very helpful.
thank you!
That was great !
Nice, useful information!
I like how you smiled more at "69" you definitely had a laugh before the edit.
instablaster
Great explanation. Thanks very much.
Thank you!!
Thanks for a great explanation 👍 I will absolutely follow your channel
Can you do a video saying about how close speakers bookshelf have to distant from the wall?
Good information thank you.
Very helpful thank-you.
Now i fully understand, thank you
This was very useful. Thank you :)
Thank you very much!!
Great Video!
Thank you!
I have a Stereo Integrity M3 mid range. I wanna use it in a pod for my car A pillar. It has a 107 EBP... What should I do? Vented needs to be big. Will I lose quality in a small sealed pod?
Do rear ported speakers send more sound to the back wall? My speakers will be on a party wall and want them firing as much sound forward as possible, I Can't seem to find this answer anywhere.
Thanks in advance :)
I want to keep my box from being too big and plan on using 2 identical woofers, is it possible to have good results with one being in a sealed chamber and the other in a vented portion? in parallel or I could design individual crossovers to make a 2.5 way. Has anyone ever done this? one sealed and one ported in same box? thanks
super informative thnks
What if i'm using large loud speakers that have 10", 15" and 18" woofers in my atmos system as well as 10" subs? my LCR are all 15" as well as the surrounds and rear heights. my front heights are 10" and my surround rears are 18". All the speakers are ported including the subs but the 18's are sealed. would this all cause infinite sound problems?
I've found the room plays a defining part in what sounds best with ported vs sealed. My sealed kef q550 sounded great in a small room, loads of tight bass, but too weak in a medium room.
I just picked up some ported kef r500. Will be interesting to see if they have too much bass or sound muddy and boomy in the small room and ok in medium size room.
I mean they were twice the price, and supposedly a better speaker, and many very expensive speakers still use ports, they shouldnt be worse speakers - IF in the right room.
KEF once used a band pass speaker box in their 104/3 and 104/2 speakers.
Hello sir, pls kindly post a video for how to calculate speaker cabinet for a speaker.
My JBL studio 580 has a port and a port insert. I keep the insert installed. Can't tell much boost with it out but the bass is definitely more smeared. It might be different if they weren't close to the back wall.
I think the speaker if it is specifically designed for use in a sealed enclosure it will not perform so well as a ported, and vise versa
Hello sir, your videos are more informative and educative. Actually I have made a 10 litters sealed enclosure for SB ACOUSTIC MW16P-4 6.5” mid bass driver and I have crossed it at 80hz high pass and 300hz for low pass. My concern is whether this specific driver is suitable for sealed enclosure.
Wow. The only useful video on this matter. LITERALLY!!!
Thank you very much
What about TLs?
So I have ported subwoof currently but prefer sealed subs.
What would happen if I use something to plug up the port of the subwoof? Would it cause any damage?
Afaik lots of people do that.
I have sealed in my car because I don't want a giant sub taking up all my space.
I have sealed in my apartment because I have a small space. Sealed won't play as loud as ported. But all my stuff is high power so I get big bass out my speakers.
Lots of factors room acoustics and types of music played. For home theater ported hits low and hard. For Rock music I love sealed you really hear and feel the drum notes.
Good and informative video. My only question left from this video is where does a sealed box with resonator sit, is it close to a ported design, or a sealed? Or is it better suited for entirely different driver characteristics?
Hi Peter, are thinking of a passive radiator? in that case its closely related to ported, but has its own calculation due to weight of the cone and stiffness suspension will affect the result. A resonator is not intended for a box, its also what is called a tactile transducer or an exciter, they get mounted on the structure where you sit typically.
A friend has late 70's Infinity Reference Studio Monitor Speakers , they have acoustic suspension cabinets, their sensitivity is only 88db and therefore the speakers are not easily driven , now he want to know
can making a bass port hole in the cabinets on the front make them more efficent , if yes , by how much db in your opinion, thanks in advance for your valuable answer.
Hi Rodney and a good question, unfortunately, it will change the speaker too much to put a port in it, you will get a lot of bass decay because a closed box requires rather high Q drivers and ported low Q if the drivers are something around the middle you potentially can, but the box will typically need to be bigger on top of adding til port. I highly recommend adding a subwoofer, because your speakers very step response will go, and that nicely nuanced bas from Arnies early designs I think is really something, so I will highly recommend not to do it but add a subwoofer, either SVS or Earthquake MiniMe if you really want some juicy lows.
I wouldn't recommend it at all. Ports have to be specially tuned
Nice video explanation. I'm interested in building a small, around 27 liters speaker cabinet for a full-range SB Acoustics SB20FRPC30-8 and I found that the Efficiency Bandwidth Product (EBP) is 83. Does it mean that this speaker driver is more suitable for a ported speaker or is it ok for a sealed speaker cabinet?
Nope you have to look at the QTS if > to 0,45 u can go sealed
I made a compromise. I used both in the same pair of speakers.
My fs/Qes is 126. What should I choose
Ported
i have a 18" 4500W sub that i have in a 10.5 cubic foot enclosure, tuned to 34hz. i just did the math and my ebp is 42.2... i had assumed this was meant for a ported box and the mfg also says either or BUT if the ebp is anything to go by... i should try a sealed box o.O. its quite peaky right now (to be expected) so maybe if the sealed smooths that out i could add a second to help bridge the gap in the output from a ported to sealed... edit: fs=24.9, qes 0.59, qms = 7.38
Hi John, yes that gives you a qts on the driver of approx 0,55 so I will recommend a closed box if you want nuances and a nice natural roll-off , but you will get less extended lows.
2:32 was before
2:34 is after
Me: Wow, what skin products do you consume?!
closed with subs paired
Jesus, so I’m not crazy when I play with all my unique woofers. 😂🤣😅
69 is the best. CONFIMED!!! 🤣
my problem with ported designs not even time smearing, but rather i dont like to hear 'woo-woo' produced by box, i would much rather listen to clean signal.
and after you know how closed box sound you just cant un-hear this nasty woo-woo sound that just masks the bass, if anything
This is nice. Very good explanation. How can we have a chat. Want to talk more about this. Instagram?
Overbased (most systems) are crap. Meaning, they sound like shit. It's more base for the sake of more base. It's like a woman with a BBL. yuck.
A sealed enclosure is clean and tight. It's like a natural slim fit woman, a dancer for example. yummy!!
Sealed is amazing but doesnt work for all drivers for a balanced natural response, there is no getting around looking at each driver. You need a fair amount of qts compared to your fs not to role off to soon and make it unnaturally anemic.