Sub Design?

cj.9

Member
2002-03-29 7:01 am
alaska
Hi,

This is my first post so take it easy.... I would like to build a second sub to add to my current home theater system, (B&W DM300 series - front ,center, surrrounds and asw500 sub. Denon 1802 recvr.)

I am thinking of using the Dayton 12" Titanic MKII in a vented box , EBS.
The white paper posted for the MKII Vented gives the following:
Box Volume 4.83 ft3
Fb 19.47 hz.
Vent 4"D x 15.2" L

Anechoic Response
F3 21.43 hz
F10 15.1 hz
Output @ 20hz - 101.5db

Typical In-room response
F3 13.7
F 10 11.0hz
Output @20hz- 119 db


I am planning to use Model 50-6281 250 watt sub amp from MCM Electronics and use Sonotube for the enclosure with MDF top and bottom.

I used the Sonosub Construction Kit software to calculate .
The software says the 24" Sonotube will be 21.78" and the port will need to be 4"by 15.2"

This will be my first DIY speaker project and I would like some opinions or suggestions. I'm not a true audiophile but I am slowly learning.

Please let me know if I'm on the right track or out in left field.

Thank you.
 

cj.9

Member
2002-03-29 7:01 am
alaska
The Shiva looks great. How close are you? Any pictures?

I ordered the amp from MCM yesterday. Not sure how long that will take, but I won't be able to get started for a couple of weeks anyway. If I don't decide on the speaker ,it may be a little longer.


Keep me updated on your progress....


:)
 
vents

Griff, howdy.
With the 142.5ltr vented shiva are u using flared ports, if so where did u get them from?
Im going build the 85ltr vented shiva but cant find the flared ports in australia, so I was thinking of making the box with a slot port any ideas?
Whats the go with correction factor on slot ports? something about friction of the air in the port?how do u work it out?I use Winisd which doesnt factor this in I've heard?
help!:confused:
thanks Rolfy72
 

griff

Member
2001-12-27 4:01 am
Melbourne
Slot port isnt really the way to go, from what ive heard if u dont stick to the plans pretty accurately then they will turn out a little less then anticipated.

There is a place in Melbourne that can do the Flared port and they have another nice trick that you might be interested in, i am looking for the same ports and i am going in tomorrow to pick up my SEAS drivers and looking at the ports. I will get pricing etc for you and be back in a day.
 
cj.9, I made my first sub with sonotube, I used a NHT 12" with a 250 watt amp. The enclosure was sealed. I did not like the looks of the sonotube and after about 2 months I built an MDF enclosure. I cant recall the exact volume but can send it if you need it. I wanted very low bass and did not want the enclosure sympathetically vcibrating so I put alot of braces in the inside. When it was complete I finished it in cherry. My main speakers are 2 way Seas excel magnesium with seas excel tweeter. The sub is great for movies but tends to be too much for normal music listening, the room it is in is about 18 by 14. I think the sub would be better in a larger room. Just another opinion!
 
I built a Shiva sonosub and love it. Ported, tuned to 16hz, but I go down to about 13 in room, and the rest is room resonances. Used in conjunction with an AVA-250 amp, barely feeding it any power for music for proper integration (doesnt take much to overdo it). The thing can pump out SPLs like its nobodys business, yet its very tight. Perhaps the most important thing was fiddling with the phase on the crossover, its just under 180, and it eliminated any "lag" associated with the transients otherwise.

Only thing I saw wrong with that original design was the in room f3 of 13hz. On a sub tuned to 21hz, that seems a bit of a reach in my opinion.

Oh, and if that amp comes with a bass boost, I strongly recommend disabling it. That thing will really make your music sound horrid (theres no easier way to put it, its truly annoying).
 
cj:

Speaking of the Sonosub construction kit, do you happen to know if it takes into account any stuffing being used?

I'm about to start building my first Shiva sonosub and am trying to make sure I get everything right the first time :D

I think I'm going to go for the 85L version. Seems like a good compramise between accuracy and HT use.
 
142L ported shiva

I made this design last summer and I have been very pleased. The bass is not overpowering for music as many commercial subs are. The EBS alignment can really shake the walls for home theater though. I would guess weight around 100lbs, very heavy. The design recommends no stuffing, but I found lining the walls with a small layer of polyester stuffing made response a little more smooth. Also, take extra care to make sure there are no air leaks in any of the joints. Keep us updated on your progess.