I am on a very tight budget. I have a 15" powered subwoofer in my house right now that I am satisfied, but I have an itch for attempting to build things all the time. My skills are not the best right now but I can learn fast, and this is what I enjoy doing is learning new things.
The sub I own is this: http://www.buy.com/prod/bic-america-.../90136869.html
I have since modified it some. I did not like how it can bottom out when watching some high level LFE movies and what not. I replaced the driver with an Audiobahn 15" car subwoofer I found at a garage sale for $20 brand new. The driver has more excursion capabilities. The original does look "whimpy". I would not have bought it if it were not so cheap. After replacing the driver the low end has improved, especially adding a good bit of stuffing on every wall, but being sure not to block the port.
My problem is that although the bottom end has improved, and has more extension, the lows are not as loud as the 50-65Hz region. I realize that you cannot just take a driver and throw it into a box and have it work optimally, this is why I want to build a new enclosure for this driver.
I will be using sonotube. I should be getting 22" diameter sonotube from my father in law who works in concrete. The driver's T/S (while probably a bit "optimised" in a marketing fashion) are not quite enough to get full sims of excursion and max spl/power in winisd pro, but this is what I have. I will be using the built-in plate amplifier the BIC uses, which should have 275 Wrms, 600 max. The amp is a BASH amp, with variable LP, Phase, Hi and Low inputs. The WinISD Port air velocity is with 300W input power. I will be rounding the ends of the vents, and usually do not have the subwoofer playing too loud anyway. I don't feel I will have trouble with chuffing as I do not with the current setup, the BIC with a box a bit too small for the driver, and a single 4" flared port.
Thanks for taking the time to read this! I'm open to all criticisms.
The sub I own is this: http://www.buy.com/prod/bic-america-.../90136869.html
I have since modified it some. I did not like how it can bottom out when watching some high level LFE movies and what not. I replaced the driver with an Audiobahn 15" car subwoofer I found at a garage sale for $20 brand new. The driver has more excursion capabilities. The original does look "whimpy". I would not have bought it if it were not so cheap. After replacing the driver the low end has improved, especially adding a good bit of stuffing on every wall, but being sure not to block the port.
My problem is that although the bottom end has improved, and has more extension, the lows are not as loud as the 50-65Hz region. I realize that you cannot just take a driver and throw it into a box and have it work optimally, this is why I want to build a new enclosure for this driver.
I will be using sonotube. I should be getting 22" diameter sonotube from my father in law who works in concrete. The driver's T/S (while probably a bit "optimised" in a marketing fashion) are not quite enough to get full sims of excursion and max spl/power in winisd pro, but this is what I have. I will be using the built-in plate amplifier the BIC uses, which should have 275 Wrms, 600 max. The amp is a BASH amp, with variable LP, Phase, Hi and Low inputs. The WinISD Port air velocity is with 300W input power. I will be rounding the ends of the vents, and usually do not have the subwoofer playing too loud anyway. I don't feel I will have trouble with chuffing as I do not with the current setup, the BIC with a box a bit too small for the driver, and a single 4" flared port.
Thanks for taking the time to read this! I'm open to all criticisms.
Attachments
It looks as though the (two) four inch ports may end up chuffing at 20Hz with 300W. I hear if the ports are flared you can get away with more than 57 on that graph. Am I somewhat right about this?
That amp has a Hi-Pass filter around 20 hz, it doesn't appear you accounted for that in your modeling. 9 cu.ft. tuned to 22 hz with 350 watts input power and a Hi-Pass filter at 20 hz results in a port air speed of 25 m/s when using two 4" flared ports 13.5" long each. Cone excursion is within Xmax assuming the 14mm Xmax listed is one way and not peak to peak.
Here's the project file.
View attachment Audiobahn 15.zip
Hmm. I could open the amp up and disable the HP filter, but would it do much good in an enclosure tuned to 19 anyway? I probably might as well tune a couple Hz higher huh.
Thanks!
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.