Tweet
I am looking to get this subwoofer and would like to have it in a ported box. I have looked all over the net trying to find a ported design for this sub. With no such luck. I was wondering if any of you guys have come across one or could help me design one.
-
-
Hello Mike,
The RSS315HF is not really a great woofer for ported boxes. It would require a 5 - 6 cubic ft box tuned to ~20Hz. For 5 cubic ft this would be a 4" port 14" long. Most people do not want a box that big for a single 12. The good thing is that the -3dB point will be about 18.5Hz. Cone excursion gets to be an issue with this design. I would suggest the RSS390HO if you want ported. The box will be about 3.75 cubic feet and the power handling will be nearly double. The 3db will move up to about 22Hz.
Greg -
Greg, I'm not sure where you're getting a requirement of 5-6 ft^3 for the 315HF. Even WinISD's default recommendation is only 4.5 ft^3 with a 20Hz tuning. Personally, I wouldn't hesitate to use the 315HF as small as 3 ft^3 with a 20Hz tune...it's only down 4dB@20Hz, which should work nicely with a little bit of room gain. Even 2.5/20 looks doable with an f6=20Hz if one really needs to minimize cabinet size. At that point, though, I'd probably just go with the 315HO and an AE Speakers PR15-1050 in 2 ft^3, but it would need more power for similar output.
Anyway, Mike, the attached graph is a 315HF in 3.5 ft^3 net tuned to 19-20Hz via slot port. Measurement is in room (24'x16'x9'), corner placement about 14' to the mic...no smoothing, no EQ, no rumble filter. The null at 17Hz is mic/listening position related and shows up with every sub I measure, regardless of sub placement. Predicted anechoic f3 is 20Hz per WiniSD Pro.
For the 315HF, anything between 3-4 ft^3 tuned to 20Hz looks fine, IMO. Decreasing volume results in slighly earlier rolloff, but as I mentioned above, even the 3/20 alingment is only 4dB down at 20Hz while the 4/20 is only 2dB down at 20Hz.
-BrentAttached FilesComment
-
-
At the time I built the 315HF, I also built an identical cabinet for an SVS db12.1 driver that I picked up from a friend who took advantage of one of SVS' upgrade offers. The 3.5 ft^3/20Hz alignment corresponds pretty well to the 20-39 cylinder as confirmed both by email with Tom V. and someone who autopsied their own 20-39 for a similar clone project.
The slight difference in the two measurements is more likely from me deciding to recalibrate the meter when switching the sub being tested for some boneheaded reason. Nothing else changed except the sub being measured...same location, drive level...there was no reason to recalibrate the meter.
HTH.
-BrentAttached FilesComment
-
-
I built one of these for my friend using a 5 cu ft ported box tuned to about 20hz using a 3" port and used the Bash 300 watt plate amp. In retrospect the 3" port is technically too small but air speeds only get high enough to make noise at high volumes below like 30hz. So basically you would only get port noise during explosions and whatnot during movies, which are just noise anyawys. I've never heard the thing make any nasty chuffing noises yet.
The Bash 300watt amp is a great plate amp in this configuration because by default it has a high pass filter at like 17.7hz if I recall correctly which just keeps the sub from exceeding xmax in this configuration. The thing is a bit big and heavy but it sounds really good and for movies and HT it is quite a bit louder and lower than I expected. It will rattle the dishes in the cupboards in the kitchen.
Anyways, the thing rocks. You'd have to either be a bass head or just want a really rockin HT setup to want much more bass than one of these 12s will provide in this configuration, in my opinion.Comment
-
I'm using mine in a 6 cf box tuned to 20hz. Dayton 240 watt plate, perfect match, hits 18hz in room flat.Comment
-
Hmm, maybe i have the a bad file for this. My WINISD recommends 6.528 cubic feet!Originally posted by brent_s
GregComment
-
Parts Express provided me a set of plans for a ported box for the RSS315HF. The box as an internal volume of about 3.5 cubic feet (external dimensions of 19.25 x 19.25 x 19.75 and 3/4 MDF sides).Comment
-
I'm working on a pair of subs based around this same driver. Fitting the port a 30" long 4" port in my little box is a pain - 22x17.5x11 internal.Comment
-
i have two wired in 8ohms using a 6ft^3 box, ported, using a 4in dual flared port that 7.75in long (20Hz tune) heavy fill, and the 500w BASH amp from PE.
This thing is killer!Attached FilesComment
-
-
Nice looking sub. Nice looking CoolerMaster 690 too :P I'm using the same case for my gaming rig.Originally posted by bbecker1983Comment
-
I am building a downward firing ported sub using the RSS315HF driver. The box will have an internal volume of approximately 3.3 cubic feet, and will use 3-inch diameter port 12.6" long.
Due to spousal approval issues, the box will have dimensions of 14 x 17.5 x ~30. Would it be best to have the port downward firing as well or locate it on the side of the box? Also, is two inches sufficient distance for clearance from the bottom of the box/downward firing driver to the floor, or should the distance be greater?
Thanks
KrisComment
-
The rule of thumb is that you need atleast a port width of clearance between the internal port mouth and any walls. Also the port mouth cannot be directly aimed at (in-line and parallel to) the rear of the driver.Comment
-
A port can certainly run parallel to the driver.Originally posted by bemis23
If possible the port terminus shouldn't directly behind the driver. If however that's the only option then run with it.
IB subwoofer FAQ page
"Complicated equipment and light reflectors and various other items of hardware are enough, to my mind, to prevent the birdie from coming out." ...... Henri Cartier-BressonComment
-
Of course it can be parallel, but it's best if it's off axis to the cone. That's all I was getting at.Originally posted by ThomasWComment
-
Just built this for a friend:
~2cu ft. (if i remember correctly) sealed RSS315HF with a 500w amp. Sounds great IMO.Comment
-
While you're never doing a driver any favors with horizontal mounting, the 315HF exceeds the recommended sag factor of 5% at 5.5% according to WinISD. IOW, you've lost 5.5% of your Xmax before you send it the first watt before you get into the cumulative effects of gravity working on the suspension 24/7. If possible, I'd only go with the horizontal mount as a last resort.Originally posted by kvardas
-BrentComment
-
I built a subwoofer cabinet for the RSS315HF-4 driver. The cabinet has an internal volume of 3.4 cubic feet, is lined with 1" sound barrier foam, stuffed with poly fill, and has a 12.6" 3-inch diameter port. I am using an NHT SA-2 amplifier and have the crossover set to its lowest frequency setting of 35 Hz. The subwoofer sounds ok and very modest levels. Anything louder and it really rumbles. I wonder if a higher quality subwoofer amp would generate better results. Pictures of the cabinet to follow.Comment
-
Here is a pic of the cabinet. Volume, port length/tuning per plans from PartsExpress,Attached FilesComment
-
-
why do you have the crossover set at 35hz? Are you using mid-bass modules?Originally posted by kvardasComment
-
Good looking build! What kind of veneer is that? My subs are still sporting the raw MDF look while I decide on a finish.Comment
-
Crossed any higher and the thing starts to sound bad. I have a nice pair of M8ta speakers built per Jon's specifications. I wanted to add a bit of low end, of which I think the M8tas need just a bit.Originally posted by kevinp.
The veneer is stripped mottled makore (19" wide!)Comment
-
This topic keeps coming up. The problem is that PE changed the RSS315HF-4 specs a while back and never changed the model designation (like adding an "a" to the model).
The old specs were Qts=0.45, Vas=77.5 l and Fs=24.75 hz
This gives an optimum ported box of about 3.6 cu.ft. tuned to 23.5 hz.
The new specs are Qts=0.49, Vas=85 l and Fs=21.0 hz
This gives an optimum ported box of about 4.9 cu.ft. tuned to 18.25 hz.
(I used tunings that result in no bump before LF roll off.)
PE is still giving customers the box design from the old specs and the old designs keeps showing up around the net. These no longer work with the current driver.
So keep in mind that the latest version of the RSS315HF-4 requires a box that's one-third bigger than the old one. In exchange, you do get a lower tuning.
-BobComment
-
Well, could I close of the port and use the 3.4 cu ft. cabinet in a sealed arrangement?Originally posted by BOBinGAComment
-
That would certainly work.
Another alternative would be to use an amp with some type of LF equalization like the O-Audio 500 watt amp. You could keep the 3.4 cu. ft. box, probably increase the port length to tune it to 13 - 14 Hz and use the amp EQ to add 6 db at 16 hz. That would get you flat down into the teens and well over 100 db without exceeding X-max. (Use the EQ/Filter tab in WinISD and add a second order peaking high pass with +6dB and 16 Hz to mimic the O-Audio EQ to see what you get.)
-BobComment
-
I ran your box and tuning in WinISD and it does not come out too bad. There is a couple of dB peak, but not bad. If it sounds a bit boomy, you could simply increase the port length a couple of inches or move it away from corners and it would still work pretty well. So don't worry about your current box unless you find it a bit too agressive. Keep it out of a corner and it should work just fine. If it has problems at high volumes, it could need a larger port. A 4" port would need to be about two feet long if you can fit it in the box.
-BobComment
Comment