tade no subwoofer.

[tade]

I am looking to build a ported sub with good extention. I live in a concrete box of a dorm room so i figure room gain should be taken into consideration. I am torn between:
http://www.partsexpress.com/pe/pshow...5&ctab=10#Tabs
and
http://www.partsexpress.com/pe/pshow...0&ctab=10#Tabs

And if you told me this was a good investment.... I might consider it.
http://www.partsexpress.com/pe/pshow...99-665&scqty=1

Because they are both cheap and seem to be able to move a lot of air. the dayton dvc comes higly recommended, i like the dvc.
Should i plan for room gain? I was thinking making the port variable length.

Right now i just need a driver so i can sink my teeth into the project, please help!

Many thanks

[DcibeL]

How about one of these?

High fidelity
High Output

[tade]

the first link is broken i think, and the second is a single voice coil. I think haveing a dvc would simplify things. though, my amp does have a bridged mode.

[DcibeL]

Fixed the first link. Basically the high fidelity sub is made to work in a sealed box, while the high output is made to work in a ported box (I think). I cannot recommend that big buyout driver, from what I have read it is built for high SPL and not high quality sound. For the price a much better sub could be bought. If you wanted to spend that much money I would have to recommend the Peerless XXLS 830847. It is a dual 8 ohm voice coil subwoofer for ported boxes and sells for $164 at madisound.

[tade]

this will be a better performer than the dayton dvc 12?
I also really like the idea of a sealed box, but i really dont want to get into bass boost circuitry. I think i am scared. Plus, ported ought to give me better efficiency down low. then again, a sealed box can be made small and solid, and with a high enough power woofer and the proper circuitry can go low too. Is the bass boost ciurcuit very complex?

thanks for the help!

[tade]

I am really feelin that hi fidelity subwoofer. I think i am going to go for it because when i continue building my soundsystem, stereo bass might be something i am interested in, and i think these drivers seem quite nice.

I am paying around with Winisd, and have two options in mind. I can build a large box suitable for anechoic bass which is close to flat to 21hz with a minus three at 17hz, or i can give myself a long slow rolloff with a minus three at 21hz. How should i decide to go? should i do the rolling one and count on room gain? The nice low tuning frequency required might help dampen rumble frequencies.

thanks

[DcibeL]

I do believe the new Dayton reference subwoofers are very hard to beat for the price. They provide a very good competition to the Peerless XXLS for a less cost. Since you are in a dorm room I would go for the slow rolloff as a small room will have quite a bit of "room gain" over a larger room.

I believe the bass boost circuitry you are referring to is a Linkwitz Transform circuit, which unless you are experienced with electronics I would stay away from it. A nice ported box is always a good start.

In my system I use an Atlas 12" with a long slow rolloff to get better bass extension, and it sounds just great in room.

[tade]

excellent, wood is cheap, i am gonna do it!

I have heard that you shouldnt stuff a port. but i think i may be able to use that in tuning. can i stuff a port to allow me tune from between twenty five and fifteen hz? or will the stuffing be more of a between 20.5-19? Also, do you thin it would be too much of a leap of faith to make the box 40% smaller and stuff it? i figure a smaller box will be stronger.

[DcibeL]

Someone else will have to help you with the port stuffing question, but I believe stuffing a port will have more of an effect of an aperiodic vent on a sealed box, rather than changing the tuning. I could be wrong though, as I haven't looked into it.

40% smaller is overkill for the effects of stuffing a box. Something like 20% seems more realistic to me. I have never seen anyone heavily stuff a ported box, so I think it is safe to say it's not the best idea. I have always padded the walls of my (ported) sub boxes with polyfill, but nothing more than that. A large box can be just as strong as a small box provided it is properly braced internally.

[Volenti]

Originally posted by tade
excellent, wood is cheap, i am gonna do it!

I have heard that you shouldnt stuff a port. but i think i may be able to use that in tuning. can i stuff a port to allow me tune from between twenty five and fifteen hz? or will the stuffing be more of a between 20.5-19? Also, do you thin it would be too much of a leap of faith to make the box 40% smaller and stuff it? i figure a smaller box will be stronger.

Stuffing the port or the box won't allow you to tune the response the way you think, it will damp the resonance of the port/box system, reducing the output of the of the port at resonance.

It's usefull for taming the response of a boomy sounding enclosure, but won't change the tuning frequency.

Stuffing does not make the enclosure appear larger to the driver, it changes the damping and roll off of the driver to be similar to a larger enclosure but with reduced efficiency.