Need help guys...want to make a horn box

[GM]

Ducted port:

GM

[pat allen]

the driver is an Alpine SWR series, this speaker is specifically designed for sub boxes.
its a dual voice coil rated at 1500w peak per coil.

Xmax pk to pk is 65mm.

thanks.

[pat allen]

Originally Posted by GM

This driver isn't efficient enough for high output at low distortion in a simple reflex, but if it has at least 15 mm of Xmax, then it will in theory do the DD/DTS/THX 115 dB reference at 1m/400 W, but this is based on the listening position, so either some room gain or more Xmax will be required to meet it.

Here's one like you want, but FWIW, a ducted port alignment is theoretically slightly more acoustically efficient in slightly less bulk.

GM

PS: driver brand/model for my records please........

thanks for all the numbers, there is something i am not doing right, my screen is different than yours, maybe i dowloaded a wrong version ?
and for the human alike, the S numbers are the volume of each section of the throat righ ? i try hard to understand here...i am begginer with thoses designs.

[pat allen]

ok, i corrected my drawing a litle bit.

The reason i want to make such a box is because i heard one designed like that and the bass was soo deep. Maybe my expectations are wrong but at least this is easy doable.

At first i wanted to make an equivalent front loaded box with a single port, the port beign at the back and the lower portion beign just a rough horn.

Volume A beign around 75L
Volume B beign the port, which is a rectagular calculated port at 1" by 16" by 20" long, for a tuning frequency of about 24hz,
and volume C would be just some sort of exit/horn...
maybe it sounds too simple mind, let me know what you think.

[BP1Fanatic]

Originally Posted by pat allen

the driver is an Alpine SWR series, this speaker is specifically designed for sub boxes.
its a dual voice coil rated at 1500w peak per coil.

Xmax pk to pk is 65mm.

thanks.

The SWR-1242D only handles 500wrms (250 per coil).
Alpine SWR-1242D Type-R 12" subwoofer with dual 4-ohm voice coils at Crutchfield Signature

I can't believe Alpine-USA won't provide the T/S parameters on their site.
Alpine Electronics of America, Inc.
Alpine Electronics of America, Inc.

[pat allen]

Originally Posted by BP1Fanatic

The SWR-1242D only handles 500wrms (250 per coil).
Alpine SWR-1242D Type-R 12" subwoofer with dual 4-ohm voice coils at Crutchfield Signature

I can't believe Alpine-USA won't provide the T/S parameters on their site.
Alpine Electronics of America, Inc.
Alpine Electronics of America, Inc.

yeah i had a hell of a time finding the specs. the canadian web site is down btw for several years.
on the data sheet i have it says 1500w peak per coil, 500rms. Anyway, for what it changes...

[GM]

Originally Posted by pat allen

thanks for all the numbers, there is something i am not doing right, my screen is different than yours, maybe i dowloaded a wrong version ?
and for the human alike, the S numbers are the volume of each section of the throat righ ? i try hard to understand here...i am begginer with thoses designs.

You're welcome!

Don't know, mine is V26.00 and don't recall it looking any different from any recent versions. Anyway, what are the differences you're seeing?

Right, they are the cross sectional areas in cm^2. For folks like me that only think in Imperial units, highlighting the values and pressing F6 brings up a conversion window.

GM

[Rademakers]

The peak power handling is that number you want to forget about, the moment you have laid your eyes upon it. It's ussually between 2,5 and 10 times larger then the actual power handling.

Best regards Johan

[pat allen]

well, i came upon the Tuba HT on BFM web site, it looks quite easy and impressive.
I am just concerned about the power handling of that sub enclosure itself, everyones states that they only drive it with lets say 25w, 60w,...and get plenty of bass. Ok, i buy the idea, but what happens if i drive it with more than 250w ?

Will it overload the box design ?

[GM]

Originally Posted by pat allen

The reason i want to make such a box is because i heard one designed like that and the bass was soo deep.

OK, but did it use this driver?

Regardless, reducing the rear chamber's Vb and adding a straight initial expansion increases its HF gain BW above 100 Hz at the expense of some acoustic efficiency with the length and flare frequency governing the shape of its pass-band response. Unfortunately, adding another section means the Loudspeaker Wizard is disabled, so you'll have to do it the old way of tediously comparing different input values instead of seeing it in real time as you use its sliders.

Anyway, using your dims and adding a 20" long flared section expanding to ~116.25"^2 (750 cm^2) yields a ~maximally flat half space response of ~23.7 Hz -185 Hz. Again though, the simple ducted port alignment I suggested yields more bang/buck and easier to build, but being more acoustically efficient it's ~50% bigger also, though still tiny by my standards for a 'sub'.

Note that published specs are probably off enough to render all this moot unless significant EQ is used.

GM