Centersub

[evorkahn]

hey. I was looking around on partsexpress site and an idea come to me. what do you think about a subwoofer with 4x aura ns6 drivers powered by a Dayton Audio SA240 . will be used as a centersub. want to make it as cheap as possible.

can someone help me with an enclosure in 0.75 mdf and with 2 ports . would like to have it 10 inch high the rest dosent matter because the tv will be on top of the it.


sorry for my english. im just a diy rookie from europe

[engr_dave]

With 55Hz Fs and 3.9mm xmax, these 6" drivers aren't going to go very deep as a subwoofer. Curt's "Stentorian" uses six of these per side in fairly large [sealed] boxes and still he had this comment:

apparent f3 down at least into the 50's, with 40's still being audible. I still recommend using these with a subwoofer, but they shouldn't disappoint if you don't.

[JonP]

Just off the top of my head, you might look at one 12" Dayton SD315A-88, for about $10 more than the four Aura's... Not the most extreme sub in the world, but it's a 12" with low Fs and 7mm xmax for under $60. It'll make some decent bass, probably do a MUCH better job than the Aura's...

Give it a model...

[evorkahn]

12 inch is to big. im more looking for the midbass actually. find out that i can spend a lot more money on this and will go up in quality. what about two Dayton Audio RS225-4 and one port. still same size and amp i wrote in the first post. more intersting drivers now??

[BOBinGA]

evorkahn,
Sorry for the late post. My main speakers use one RS225S8 per side in 1.75 cu.ft. boxes. While these are great woofers, they are still not subwoofers. I could certainly get by without a sub with them. But once I added an RSS265HF-4, the difference was obvious. The RSS265 is a true sub and the RSS225 is not. If size is a problem, use the RSS265HF-4 in a 1.75 to 2 cu.ft. ported box and you will hear what a real sub is. Granted, there are better subs that will go even deeper and louder, but for the size and money, the RSS265 can't be beat.

-Bob

[evorkahn]

thanks for shearing your experience with me


havent build or bought anything yet, just planing and getting some suggestions. its a sub for the center so size is an issue and money aswell. its my first build so wont spend so much money on this one. maybe I build something better if this turn out good.
the boxes you got with the rss225 are they ported? if so how big is the port? will most certain add 2 subwoofer for my surround later. think Im going for Dayton Audio RSS315HF . I havent decided on the 4 or 8 ohm.. my amp choice will decide that. I need to buy a new surroundreciever and maybe a effect for my front before I start with them.

[BOBinGA]

Yes, they are ported. I used PE rounded ports:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=260-478

I just used them uncut since the 8.5" length gave me the tuning I was looking for - about 27 hz.

I used the old shielded version. The newer unshielded RS225 will need a slightly smaller box and higher tuning. Based on the published specs, I ran it in WinISD and came up with a 1.5 cu.ft box tuned just over 31hz with a 2.5" x 7" vent.

-Bob

[evorkahn]

thank you for you effort.. could you ran it in winisd again with 1 and 2 woofers and with a
Precision Port-flared. will it be best with 1 or 2 ports when having 2 woofers in same box?

[BOBinGA]

With the precision ports, I would suggest using either two 3" ports or one 4" port if you use two woofers. Either one will work the same. These are large enough to prevent port noise. Rather than give all the port lengths that would work, I'll give what I would use for the tuning frequency for different box sizes. With two woofers, you can use a single box anywhere between 3 and 5 cu.ft. (85 to 140 liters). The larger the box, the lower you tune it and the lower it will play. I would suggest these tuning frequencies:
5 cu.ft. use 26
4 cu.ft. use 28
3.5 cu.ft use 30
3 cu.ft. use 31

I compared the port length calculator in WinISD and the one on the Precision Port web site and they are within a mm of each other, so once you decide on the box size based on your space requirements, go to the Precision Port web site calculator and put in the volume and tuning closest to the examples above to get the port length.

http://www.psp-inc.com/tools.html

Remember that the volume you put in the calculator is the net volume. You have to subtract the port volume and driver volume from the gross interior volume of your box. Remember that you do not have to extremely precise with the port length. You can change the length a few centimeters either way and it won't make any audible difference. The calculator also assumes that you line the inside of the box with foam. When its built, you can then add stuffing if you want.

-Bob

[evorkahn]

thank you so much for the effort you have put into this. really appreciate that you will help a rookie like me thank you for the link for ports and let me read and find out whats best for me. will write here what i came up with

[BOBinGA]

You are welcome. Let us know what you decide.

-Bob