diy sub/tv stand

sophie wrote: »

I'm going to build a sub enclosure to use as a stand for a 42" tv and my m5jr's. I am thinking of using 2 dayton 15" Reference HF drivers from PE, one on the left side and one on the right side. the enclosure is going to be 14-18 ft^3 with a port tuned to 23hz. to keep the weight down i'm planning on single 3/4" mdf sides with bracing every 8". Does anyone have concerns about the enclosure being to weak or putting electronics on top of this?
I don't know what im powering these with yet...thinking about a crown xls1000 or two 500W bash plates. any input?
can someone tell me how to figure out what port size or how many I need using winisd?

Thanks,
Payton

That size sounds right (7-9 cu per driver) but I think it would be better sealed usually porting sounds good at one are but not so good at the others , I built a 5 cubic ported tuned at 23 hz it was a failure ,Than I went sealed at 8 cubic feet and got that from winisd , I am using a dayton single quatro 15" and a parts express sa220 plate amp .
You can try isoberic clamshell design , my mtx 12 (2 of them) goes lower than my 15" I get 109 db at 20 hz w/300 watts . Dont try a crown XLS 402 I just sold two it wont push the sub under 25 hz .
Why are you going ported ?
I am willing to bet if you sealed 7-9 cu you will get a better sounding bass and you wont need a monster amp , on winisd it shows curves power in vs db output and at what frequency , with that you can see how much power you need , maybe winisdpro will be easier .
I dont think it will be wak but I would br concerned about magnetics plus early failure shaking the tv plus it way produce a unclear picture during the deep bass you will have to isolate the tv's base .

I see less spl in the sealed but a smoother curve (less hump) than the sealed , I cant read your graphs what driver is that for ??
Its possible a ported cabinet will have more spl but my past experiance with all ported home subs just gave me not that nice a sound , wont you get a smoother curve but will need more power ?
Your graph shows 15 cu feet with one driver I thought the plan was 14-18 for 2 drivers , when 2 drivers are in a box (except isoberic) the drivers share the volume so thats 7-9 cu per driver .
Also I think you are using one enclosure so remember 2 ports will act differantly so a single port is better .
Why not build 2 boxes one for each 15 and make each a stand ?
Also how much power did your graph say it needed ?
it may be there but no matter how much zoom I try cant see it .
at 20 hz its like 5 db differance , a buddy of mine runs 4 of the hf 15" with a adcom multi ch its like 250x5 wpc if you pm me your email address I will have him write you .

http://www.the12volt.com/caraudio/boxes.asp
http://www.decware.com/newsite/diy/decware/Plans.html
http://www.mobileinformationlabs.com/HowTo-1Woofer-Box-CAL%20Port%20lenth%201.htm

I wouldn't set any electronics on any sub period. Why not make it into a coffee table instead of a tv stand?

I have a homemade in an 18x30 room with (1)15"/500wrms in a 4.15'^3 dual 4 inch ported enclosure. When its bumpin its like talking into a fan.

I know I'm about to get the book thrown at me but in my opinion the flatness isn't nearly as critical when your talking movies and video games as its usually the boom your after not the musical accuracy. MY.02...

Good luck at any rate. Subs are an infinite source of adjustability and entertainment. Have fun!

1C

I talked to my friend w/4 of them .
He mentioned going from 10 to 15 cu only adds 2 db at 20 hz be lucky if you notice it .
He ran it at 15 cubic feet and found that 100 watts (each) will get the drivers to exceed xmax (bottom out) .
He mentioned
http /audio.claub.net/software.kougaard/ubmodel.html

its kristian Ougaard's unibox spread sheet if he has excel .
have fun

sophie wrote: »

what kind of enclosure is he using? I don't see how he bottomed out the drivers with 100w unless he was below the tuning frequency or using a sealed enclosure without a high pass...

Payton

On yours I think he ran the graph ported w/out any subsonic filter, that driver has a 2.5" voice coil and is kinda effeciant ,when the box is bigger it will have less rear resistance on the cone so it can exert very easily so w/out a filter low bass will kill it .
He uses a adcom ?7500? its 225x5 WPC w/like 4 db headroom it has plenty of power he uses one channel for each 15" his box is sealed , I think his are like 3 cubic each he uses a audessy to tune it .
W/out the audessy he would probebly need to go bigger and four of them each being bigger wife would really be unhappy .

SDA1C wrote: »

I wouldn't set any electronics on any sub period. Why not make it into a coffee table instead of a tv stand?

I know I'm about to get the book thrown at me but in my opinion the flatness isn't nearly as critical when your talking movies and video games as its usually the boom your after not the musical accuracy. MY.02...
1C

Agreed 1000 times over about electronics on the sub. I would go with a table top on it and do a wall-mount for your TV.

I also agree about accuracy not being so necessary with movies and games. It's that ultra low thunder and boom that you're typically going for.