Hello all,
Please take a moment to look over my sub design.
The sub will be 80% HT and 20% music.
I'll be using this sub:
Dayton Audio RSS390HF-4 15" Reference HF Subwoofer 4 Ohm
In a 9 cu ft net vented box
Three 4" vents (could be flared, not sure yet) 24" long
I will attach the PDFs from bassbox pro with the results
Any feedback would be great
Thanks in advance.
Please take a moment to look over my sub design.
The sub will be 80% HT and 20% music.
I'll be using this sub:
Dayton Audio RSS390HF-4 15" Reference HF Subwoofer 4 Ohm
In a 9 cu ft net vented box
Three 4" vents (could be flared, not sure yet) 24" long
I will attach the PDFs from bassbox pro with the results
Any feedback would be great
Thanks in advance.
Since you will be using it for some amount of music, I would suggest keep the enclosure tuning about the same as you have in now but use a slightly smaller enclosure (around 6ft^3) which will result in a little higher F3 but a more gentle LF slope that will be more pleasing musically. In addition you should be able to use just 2 - 4" ports and not experience any port compression or "chuffing".
Design looks good as long as a suitable HP filter is used (around 17 Hz BW 24).
Vent size seems a bit small for full power use.
Flared vents would be prudent for as much displacement as the speaker has.
A "top hat" vent could reduce the length needed for the same tuning, which may reduce the pipe resonance the long small vents will have, which does not show up in bass box 6.
What is the excursion with 500 watts?
What power level does it take to hit the 14mm Xmax?
What is the vent air velocity at 14mm excursion, 18-20 Hz ?
What power will be used with the sub ?
Attachments
Thanks for the responses.
Bassbox pro said that three 3" ports would not meet the "minimum port diameter". I would like bery much not to have any chuffing. Is it more wise to model in winisd? I find the program less user friendly, but I do have it and can try it.
As far as going down to 6 cu ft for better music reproduction; would I need to be concerned about losing low end for home theater? This will primarily be used for home theater. Music will likely be during entertaining only and would be at low volume.
Bassbox pro said that three 3" ports would not meet the "minimum port diameter". I would like bery much not to have any chuffing. Is it more wise to model in winisd? I find the program less user friendly, but I do have it and can try it.
As far as going down to 6 cu ft for better music reproduction; would I need to be concerned about losing low end for home theater? This will primarily be used for home theater. Music will likely be during entertaining only and would be at low volume.
If you stay with the monster 11ft^3 you will require three 4" ports to stay under 15 m/s - the other thing you should be aware of with the 11ft^3 enclosure tuned to 16Hz, is that you will be limited, xmax wise, to a max power of 236 watts.
If on the other hand you take my suggestion of using a reasonable size 6ft^3 enclosure tuned to 16Hz you can drive it to 325 Watts without exceeding xmax, will only require two 4" ports to stay under 15 m/s and have a sub that actually will play louder and integrate better with the rest of your speaker systems.
As far as low end extension is concerned the f10 with the 11ft^3 enclosure would be about 12Hz vs the 6ft^3 enclosure having a f10 of 13.5 hz - I really doubt that you would hear or feel any difference - lol
Here is a quick WinISD plot of the 6ft^3(green) vs the 11ft^3(orange)
Last edited:
In the 16Hz tuning of the 6ft^3 enclosure it would require two 4" ports - each 41" long (flared at the outside end is always a good idea).
If it was my build I would think about making a small compromise and move to a 18Hz tuning which would then allow me to use two 4" ports, each 32" long (flared at the outside end is always a good idea) without really affecting the overall performance of the sub. ( fyi - will move the f10 up to about 14Hz)
winISD and Bassbox will give you basically the same results. Use what you're happy with. I was using the 9ft^3 size in my mockups. The 3" ports will not exceed 15m/s as you can see in the second plot I uploaded. Unless you regularly listen to movies/music above 105db
the port velocity of the ports would be below ~10m/s at 18hz.
Last edited:
One problem using 41" ports. You'd need the minimum box dimension of 45" on the long side which would have a panel resonance of 160hz, which is the 1/2 wavelength of 80hz. There will be a lot of energy in that box at 80hz...
Last edited:
Not necessarily, you can fold ports internally, use a slot port or even locate part or all the port outside the enclosure there are lots of options. As to panel resonances that is one of the main purposes of internal panel to panel cross bracing, to help move panel resonances out of the active passband regions that the sub will operate within.
Personally I generally try to avoid very long ports because they can start introducing undesired "pipe" effects of their own.
I have been doing car audio for many years and could certainly do a slot port. This is somthing I'm quite familiar with.
Everytime I run a sim in bassbox using a slot port I get some really long port lengths. That is if I use a typical car audio style slot port. i.e. if i use a tall narrow port, say 12" x 2" x L. That's the only reason I have defaulted to round ports. Not to mention I can just buy flared round ports. Flaring a slot port requires a little more work on the construction end of things.
That being said; I will run more sims with a slot port to check out the graphs. This time I will try to pay more attention to power handling at xmax. I don't want the sub bottoming out with moderate power.
Any suggestions? I'm still getting used to using bassbox and winisd.
Everytime I run a sim in bassbox using a slot port I get some really long port lengths. That is if I use a typical car audio style slot port. i.e. if i use a tall narrow port, say 12" x 2" x L. That's the only reason I have defaulted to round ports. Not to mention I can just buy flared round ports. Flaring a slot port requires a little more work on the construction end of things.
That being said; I will run more sims with a slot port to check out the graphs. This time I will try to pay more attention to power handling at xmax. I don't want the sub bottoming out with moderate power.
Any suggestions? I'm still getting used to using bassbox and winisd.
I played around with the sim in WinISD a little more and have the following suggestion
Driver: Dayton RSS390HF-4
Enclosure Internal Volume: 6ft^3
Tuning: 17Hz
Slot Port: 2" x 10" - 27" long - no flare required
(Port air velocity at max power - 12 m/s)
Max Power(within xmax limit): 350 W
Max SPL: 113db
F10: 16Hz
Note: requires HP filter @ 15Hz to limit xmax excursion below this freq.
Driver: Dayton RSS390HF-4
Enclosure Internal Volume: 6ft^3
Tuning: 17Hz
Slot Port: 2" x 10" - 27" long - no flare required
(Port air velocity at max power - 12 m/s)
Max Power(within xmax limit): 350 W
Max SPL: 113db
F10: 16Hz
Note: requires HP filter @ 15Hz to limit xmax excursion below this freq.
Yes, the WinISD model is net volume. I usually bounce between WinISD and BoxNotes to calc final enclosure size to achieve the targeted req'd net volume.
You could chance on not bothering with the 15Hz HP filter. Without the filter the driver won't exceed xmax until approx 14Hz and won't exceed xmech until approx 13Hz. Unless you are into listening to a lot of music by Basstronic or a lot of Techo, I really doubt that it would be a problem since there is almost no content that low in normal music files or most BR DVDs.
Hi, new here. Searching older threads as I'm contemplating building a home sub box with this speaker also. Still torn between a sealed box and a vented box. A question, hopefully without derailing the thread, is how do you get the WinISD screenshots to copy to insert here? I'll probably use mine 80% music and 20% video. Thus the thought to go sealed. Could build a second one later that is vented to help for HT situations a little more. Thanks! Jim.
Simple just hit the PrtScn key when you have what you want on your screen and then do a paste into Paint or your fav image editing program
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.