Best box design for 10" subwoofers

Hi, recently I tried to build a subwoofer box for a 10" driver with the calculation on WinISD, but I'm not very satisfied. What I've searched a lot without finding a solution is what is the best type of enclosure for a subwoofer. I mean: what should I choose between:
reflex (vented) box, transmission-line box, horn box and RTL-like box. I wish to have a subwoofer that can play as high volume as possible with a decent low frequency (30 to 40Hz).
I'm using a Pioneer TSW 254-C 10" 250W RMS driver
The attached installation manual has size recommendations for three enclosure types - sealed, ported and bandpass, including variations of each type for "Tight, Recommended, or Deep" sound preferences. I prefer sealed subs for their accuracy, smaller enclosures and simpler construction.
I know the manual doesn't have your exact model listed but that's what downloads from Pioneers site on the TSW 254-C page.


  • TS-W254R_InstructionManual062011.pdf
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Sealed preferred
Reflex works
Something which efficiency wont fit in a small place

Over the years and many builds
Not using 4 ohm and 2 ohm coils and torturing amplifiers.

And using drivers which do well sealed.
Or using a reflex which Tunes as low as possibly
In a standard QB3 or BB4

Looking at the impedance curve
Reality ends at the first peak.
You haven't said what box you built, that you weren't happy with.

Modelling in Basta with the TS paraments suggests that the 0.8 ft3 sealed box will be rolling off in the 30-40 Hz band - about 6 dB down by 37 Hz.

If you could equalise the response, of course, you could change that.

A vented box could have better extension - maybe 45 - 50 litres, with a vent tuned to about 27 Hz (80mm diameter, 310mm long), which could get you down to 23 Hz, -6dB.

Those are just estimates though. Whether it would sound good to you, I can't tell. It would depend on various things: whether you want it for movies or music (and what type of music); what your room's like; how loud you like to play it.
Sealed is the easiest to construct and obtain good results. It's very tolerant to minor enclosure size variations. Also, in my opinion they do sound the best.
Ported enclosures can be a challenge to tune and can have "port noise" which I find incredibly irritating. They are more efficient than sealed if power is an issue.
I can't speak for horns, other than I suspect the enclosures will be much larger than the other types.
Good luck with whatever you choose.
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I would like to build a sub for music that can play as much as high as possible (so I want to use ported box design) with a tuning around 30-40 Hz.
Previously I've built a ported enclosure but after doing some searches I found that i made a port a little to tight for air to pass. Also the port has one 90 degree curve, and I found that is not good for airflow.
Next I will try to build another box with a tube shape port and flanges. Hope the best.

Also I have some last questions:
-based on what I should decide the tuning frequency of my port. For example the Fs of the driver is 27,90Hz, should I go higher or lower with frequency, and how much?
-what net volume should I decide? Pioneer says that for ported box 1 square feet is good but WinISD (is this program good or not?) says that much larger is better but obviously I can't do the box endlessly big, no sense. The first try were 2 square feet large
I tried to find the TS parameters for the pioneer driver.
What are they?

Car manufactures usually recommend small boxes which make a huge response bump
at around 50 Hz usually rather horrible and boomy.

Common Reflex Alignment that always works is QB3

But that would be generalized

Tuning as low as possible, Usually few Hz Below or at FS
So QB3 be few Hz below and BB4 tunes at Fs

Lot of people tune high for whatever reason to make the graph pretty and
flat. When it is just a Transfer Function based on theory not the actual response.

WinIsd is fine it uses the same math as anything else.

It can only calculate ports that do not share walls.
Since Highest Port K =.850

If you are using a " Slot Port" that shares 3 walls or Triangle Port
which shares 2 walls Correction factor is Higher.
And need another program

For Round ports sharing no walls WinIsd works fine

Otherwise shared wall ports will be too long.
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Another 2 questions:
-what should be the optimum air velocity in the port? Ai I can choose the diameter of the port base on this as well
-has phono absorbing materia sense inside the box? In the previous box I included some phono absorbing material but nothing really changes, just the net volume of course. (Consider I'm using 2cm thick wood that does not vibrate at all, even with phono absorbing material inside)
Absorption material is not very effective at extremely
low frequency.
It is common to have none in a sub.

18 to 20 m/s is pretty normal port velocity.
At the actual linear power rating.

Not max power in WinIsd since it just applies the
power you entered for the driver.
Unless of course linear can go to full thermal.

Im curious, guess I will enter the driver into WinIsd
and have a look
Long as the box is 1.5 to 1.8 cubic feet
or 42 to 50 liters

And you can get tuning around 25 to 30 Hz
In the real world.
Should be good.

I would apply 150 to 170 watts
And getting 18 to 20 m/s velocity you'll be fine

2x Flared round port 2" to 2.5" diameter

Far as your original box is likely ok
tuning might be way lower. Can shorten the port.
Using WinIsd for shared wall port make it too long.

Either way if you can apply a little 50 hz boost
for now. to see how it sounds.
Woofer is what it is.
Would want 2 of them to get very loud.
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The mechanical parameters is actually the same. Before taking the parameters of the dvc model I let WinISd calculate the parameters for the c model, I found out they are nearly the same.

I'm sorry, I don't understand why you would use the parameters for the dual voice coil version if yours is single coil. They are similar, yes, but not the same. Maybe I'm missing something.

Anyway what I said in post 7 above is still the best suggestion I can make. (WhiteDragon's advice in post 17 is virtually the same - the only difference is 2 ports at 60mm diameter versus a single port at 80mm, which amounts to the same thing thing really.)

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