Do I Really Need A Subsonic Filter?

Maybe your like

DIYMobileAudio.com Car Stereo Forum banner

Menu Log in Sign up

Home
Forums
DIY Audio Discussions
General Car Audio Discussion

Johnmcvey32 J I recently picked up a JL 12W6v3-D4 in a Bbox ported enclosure that measures to be 1.1 cubic feet. I plan on pushing it with a Rockford Fosgate Prime Amp R500XD1, at 500 Watts RMS. I listen to a lot of rap and music with heavy bass and plan on pushing the sub hard. I am not sure of the tuning frequency of the port or the frequencies of the bass in your average rap song, but I am curious if there is there a good chance I could damage the sub because there is no subsonic filter? I will most likely build a custom box for it at some point, probably about 1.5 cubic feet with a port tuned to around 30 Hz, but then I still have the same problem. I don't really want to use a sealed box knowing what a good ported box could do with that sub. What should I do? #1 · Jun 18, 2021 I recently picked up a JL 12W6v3-D4 in a Bbox ported enclosure that measures to be 1.1 cubic feet. I plan on pushing it with a Rockford Fosgate Prime Amp R500XD1, at 500 Watts RMS. I listen to a lot of rap and music with heavy bass and plan on pushing the sub hard. I am not sure of the tuning frequency of the port or the frequencies of the bass in your average rap song, but I am curious if there is there a good chance I could damage the sub because there is no subsonic filter? I will most likely build a custom box for it at some point, probably about 1.5 cubic feet with a port tuned to around 30 Hz, but then I still have the same problem. I don't really want to use a sealed box knowing what a good ported box could do with that sub. What should I do? Sort by Oldest first Oldest first Newest first Most reactions #2 · Jun 18, 2021 Yes, you definitely want to run a subsonic filter when using a ported box. The port acts as part of your subwoofers suspension and once you're below the tuning frequency it becomes an extra stress on the soft parts and loses it's ability to maintain linear control over your cone movement. If you plan to run the sub hard it's going to be even worse for it especially since the box you've mentioned isn't big enough for that driver in the first place (jl recommends 1.3 cubes not including woofer displacement) which will make your port tuning even higher hence making your "below the tuning frequency range" higher so it runs under that threshold sooner so to speak. If you had the larger box tuned lower, you'd be in the subs goldilocks zone down to a lower frequency essentially creating less stress on the subwoofer. You've got a one hell of a subwoofer there! I have 3 of them and they sound awesome. They're sensitive to their box though, that's for sure. Use that subsonic filter. You can find your tuning frequency by playing bass sweeps with sine waves. Adjust below your tuning frequency and you'll hardly even notice it's turned on. If it's a static setting it'll be set pretty low from the factory. Probably under 30 hz. #3 · Jun 18, 2021 The problem is, there is no subsonic filter on the amp. i could seal up the port and make it a sealed box until I can get a different amp. I even considered buying an epicenter which has the filter, and I'm still nostalgic about an epicenter I had back in the 90's listening to Kraftwerk. What would you recommend for box volume and port size since you own the same woofer? #4 · Jun 18, 2021 The box you mentioned wanting to build at 1.5 cubic feet tuned to 30hz would be perfect. JL recommends tuning to 32hz but 30 would be fine. My box is 4.5 cubes tuned to 30hz and its loud. I also have a sealed box that's the same volume but not ported. It plays more linear down to about 28hz but doesn't have that over the top bass sound that you're after. It's better served for a pure SQ setup which doesn't need much volume. Just having 3 of them is more than enough...but it's never enough if you love bass lol. If your power is clean, you should be able to beat that sub all day at 500 watts rms. I have mine hooked up to a Rockford 2500.1 and they ****in boogie! I don't run em for too long though otherwise they start to smell hot. They're rated for 600 rms, not 1,000. Probably not good for longevity. I've been doing this a long time so I have a good idea when to shut it down or let it cool off before they get damaged. #5 · Jun 19, 2021 If the amp does not have a switch for a subsonic filter email Rockford and ask if there is one built in... alot of times there is one built in at like 20hz... if not use one of these on your RCA signal... they come in 20hz and 30hz... they are only 12/db so the 30hz one would likely be more useful for a pre built box.. i bet its tuned at 35-40 hz if its a bbox... www.parts-express.com

Home

Harrison Labs FMOD Inline Crossover Pair 20 Hz High Pass RCAWhat is an FMOD? The FMOD is an active crossover simulator. It is better than a much more expensive electronic crossover that requires power to operate. FMODs are packaged in pairs and can be combined with other FMODs to obtain bandpass...

www.parts-express.com

Home

Harrison Labs FMOD Inline Crossover Pair 30 Hz High Pass RCAWhat is an FMOD? The FMOD is an active crossover simulator. It is better than a much more expensive electronic crossover that requires power to operate. FMODs are packaged in pairs and can be combined with other FMODs to obtain bandpass...

www.parts-express.com #6 · Jun 19, 2021 If your box is tuned at like 35-40 like i bet it is.. you will tear apart your sub pushing it hard... and youre not going to lose any loudness, most of that is about 35-80hz in that kind of box you are running. I would get the 30hz... if its only 1.1 cu ft and ported.. i bet its tuned at like 40hz the port would be wayyyy too long to be tuned any lower. Can you post a link of the bbox where you bought it? #7 · Jun 19, 2021 The box came with the speaker and bought from a friend. 303898

0 Reply #8 · Jun 19, 2021 For the W6 in that enclosure I would close the port. Maybe not as loud but should sound a sh!t load better! #9 · Jun 19, 2021

E12SV - 12" Single Vented - 1 Inch Faceplate

E12SV - 12" Single Vented - 1 Inch Faceplate atrendusa.com Manufacturer states it is tuned to 35hz... you definitely need a subsonic filter. The in line 30hz would be perfect for your setup... the 20hz would be too low especially at 12/db slope like they are.. also sometimes you can get them on ebay or amazon for cheaper than parts express. #10 · Jun 19, 2021 Thank you everyone for your feedback! Insert Quotes Post Reply

posts 3.4M members 150K Since 2005 A forum community dedicated to all mobile audio enthusiasts. Come join the discussion about capacitors, amplifiers, subwoofers, marine and automotive audio, troubleshooting, and more! Show Less Full Forum Listing Explore Our Forums Technical & Advanced Car Audio Discussion Car Audio Classifieds General Car Audio Discussion System Design: Help Me Choose Equipment For My Car Build Logs & Project Install Gallery