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/pshowdetl.cfm?&DID=7&Partnumber=295-185&ctab=10#Tabs
and
http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=295-560&ctab=10#Tabs
And if you told me this was a good investment.... I might consider it.
http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=299-665&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
http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=295-185&ctab=10#Tabs
and
http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=295-560&ctab=10#Tabs
And if you told me this was a good investment.... I might consider it.
http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=299-665&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
Member
Joined 2003
Member
Joined 2003
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.
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!
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!
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
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
Member
Joined 2003
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.
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.
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.
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.
Member
Joined 2003
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.
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.
tade said:
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.
Those new Dayton subs do look good. Keep in mind that if you went with a vented box, cone excursion goes out of control below tuning, and for home theatre this is a problem, limiting the output due to crazy excursions on movies ... unless you have a rumble filter! Unfortunately most plate amps don't have this, hence this can stuff up the apparently simplicity of using a plate amp as a beginner project with no electronics fiddling! Consider this: if you are using all of the excursion your driver has to offer at 20 Hz and there is equal signal level at 5 Hz, you need FOUR times xmax!
With simplicity in mind, in a small room a sealed sub is most likely the quickest and surest path to getting good sub bass. You may not need any eq at all. You have both room gain and room modes, neither of which can be predicted accurately.
Another thing which can stuff up your desire for simplicity is built in boost on your plate amp! It amazes me that they think it is a good idea to include this! You have to change resistors which is not difficult, but it doesn't exactly help your warranty!
I bought a subwoofer filter kit, which includes a rumble filter, one band of parametric eq and a crossover. I actually think using this with a power amp is easier than modifying a plate amp and adding on a rumble filter.
With simplicity in mind, in a small room a sealed sub is most likely the quickest and surest path to getting good sub bass. You may not need any eq at all. You have both room gain and room modes, neither of which can be predicted accurately.
Another thing which can stuff up your desire for simplicity is built in boost on your plate amp! It amazes me that they think it is a good idea to include this! You have to change resistors which is not difficult, but it doesn't exactly help your warranty!
I bought a subwoofer filter kit, which includes a rumble filter, one band of parametric eq and a crossover. I actually think using this with a power amp is easier than modifying a plate amp and adding on a rumble filter.
The kit was AU $30 purchased from Jaycar in Australia. Getting a sealed subwoofer to go down to 20 Hz in room is a trivial matter. You might not need any eq to do it. A 20 Hz anechoic subwoofer in a small room is likely to have so much room gain down low that you will probably get bloated bottom end and have to use eq to cut it back!!!
really??? that is wonderful news, i like little sealed subs! What size for mine, winisd says maybe 2.5 cubic feet, sound good? I might also like to make it down firing. i once found a spreadsheet which would tell me weathe that was feasible, anyone know where that is?
Thanks for the support guys!
Thanks for the support guys!
You should model it in WinISD. If you aren't going to use a Linkwitz transform, then you need to make the box so that the Q isn't too high. Ideally a box that has a Q of either .5 or .707. The lower Q is better, but often quite large, so .707 is often a good compromise. Stuffing the box can also provide some damping and lower the Q.
Downfiring - this is good to animal and child proof the sub but it can also mean the sub can move itself around! Also it causes cone sag, and reduces xmax over time by an amount determined by the suspension stiffness and the compliance of the cone. An Adire spreadsheet determines if the initial sag is less than 5% of xmax, however, you will always lose some output, and this will increase over time.
Personally, I like to see the cone, its fun to watch, I like how they look and I'd rather not compromise performance in any way. I wouldn't do it. I made a sub for my parents, they don't push its performance and protecting the cone is more important, so I made it down firing. I'd never do this for one of my own subs though.
Downfiring - this is good to animal and child proof the sub but it can also mean the sub can move itself around! Also it causes cone sag, and reduces xmax over time by an amount determined by the suspension stiffness and the compliance of the cone. An Adire spreadsheet determines if the initial sag is less than 5% of xmax, however, you will always lose some output, and this will increase over time.
Personally, I like to see the cone, its fun to watch, I like how they look and I'd rather not compromise performance in any way. I wouldn't do it. I made a sub for my parents, they don't push its performance and protecting the cone is more important, so I made it down firing. I'd never do this for one of my own subs though.
I find WinISD pro gives much more useful information than XL spreadsheets, this is why I recommend it.
As far as looks go, that is entirely up to you. Something with a small footprint fits more easily into a dorm, with height to get the required internal volume. Comercial subs are typically cubed in shape, but this is less practical for placement with limited space where the sub isn't a small 1 cu ft cube.
As far as looks go, that is entirely up to you. Something with a small footprint fits more easily into a dorm, with height to get the required internal volume. Comercial subs are typically cubed in shape, but this is less practical for placement with limited space where the sub isn't a small 1 cu ft cube.
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