i have never made a HT box so im not sure if i should go sealed or ported. what do you guys think will be best it will be used 95% for movies

I am on the verge of building a HT box and I'm going sealed

for movies im guessing ud want as flat of a response as possible. So sealed or possibly Horn design

Depends on the driver you pick and the room you are putting it in. If you check out the DIY sections at most of the forums that cover home theater, they are going with very large and very low tuned boxes. By large, I'm talking 6 cubic feet for a 15" and up to 12 cubic feet for an 18". Tuning starts at 16hz and goes down from there.

-Robert

I was under the impression of the opposite assumption actually.

If you were going to listen mostly to music I'd probably go sealed at home; however, as you said your looking for 95% movie response - which is typically only going to be used then for explosions and the like, a.k.a. dramatic sequences - letting it have a good boom isn't a bad thing.

Personally, for movies, I'd build it BIG and port it LOOOWWWW!

Nothing like the feeling of reality when the movie's thunder hits or car blows up and your house feels like it was the victim because it's experiencing it's own personal shake down.

But, that's just me.

If you can build a horn enclosure though... Do it! Those just look bad ass haha.

Your best bet would be to just go the easy route first. Build a large sealed enclosure and see how that sounds. Then when thats all said and done take your time and build a low ported box. Install the woofer in the new box and see if that fits your needs better.

i have made many sub box';s just non have been for home use, like i said above the sub is a re sx/xxx i got back from scoot at fi about a year ago.

im going to look at how much rm i can give up and ill post tonight

I'm doin the same thing... but since we are in the same boat, maybe you can help me which would in turn help you too.

I have an Original Audioque HD3 15 that i plan on using for HT.

I plan on building a box about 7 cubes NET tuned around 17-19hz.

My problem is what amp to use... I dont know how much power this thing can live with to get deadly loud but i know it can take about 3kw all day.

I ran it in my car at 7.9 cubes net tuned to 29hz off of a 1500w amp and it never reached it's thermal or mechanical limits! And the recommended box is only 4-4.5 cubes so... i need a large o amp but all the amps i look at are OVERRATED and overpriced!

That is where i am stuck at and you might be too...

I tried to find me like a 12v 70A power supply, i'd just power a car audio amp on it but i cant find one... I found a 60A but i dont know if a 120A fused class d amp can run on a 60A supply for something like this...

i need a large o amp but all the amps i look at are OVERRATED and overpriced!

Then you're not looking in the right places. QSC's Powerlight and PLX series are quite good, so are Crown's upper end lines. Heck, Nick M. told me he gets pretty good results with a QSC RMX series amp, and those are available everywhere.

I think you're expecting to find the saturated market prices of 12V audio, which you aren't going to get.

If you really want the low end output for HT, take a look at what people are building. How well a sub will perform depends on its parameters. Lots of examples here to give you an idea:

http://www.hometheatershack.com/forums/diy...r-database.html

i need a large o amp but all the amps i look at are OVERRATED and overpriced!

Then you're not looking in the right places. QSC's Powerlight and PLX series are quite good, so are Crown's upper end lines. Heck, Nick M. told me he gets pretty good results with a QSC RMX series amp, and those are available everywhere.

I think you're expecting to find the saturated market prices of 12V audio, which you aren't going to get.

You are exactly right.

I am expecting to see an equivalent of what is paid in the 12v market but i am not seeing it.

Therefore.... i am deciding to run 12v amp off of a 60A 12VDC power supply. It's cheaper with more power.

I am very, very curious as to the power supply that you think you have found that makes it "cheaper"

Well, when i went to go find the link for ya, it's the Tripp Lite PR60... it's WAY wrong then what they told me on the phone yesterday..

They told me it would do 48A continuous\60A surge...

I go to their site, it says 15A... 300w 12VDC.

I got lied to AGAIN by a manufacturer... i swear, i'm gonna have to start suing companies for lying to me on the phone all the time.

I didn't think there was any way in hell it would be cheaper.

Just find a cheap old QSC amp on ebay and pick it up...

i like behringer amps too. Not top of the line, but they are decent, and you can save some money too. Otherwise as Topgun said, grab a used QSC or Crown.

i can get 5.5-6 cubes will that work? im going to use 2 layers of mdf and all theed to brace it

so i down fire and port the frount? if so should i go with a a single 6" or 2 4" ports and what should i tune it to?

i have made many sub box';s just non have been for home use, like i said above the sub is a re sx/xxx i got back from scoot at fi about a year ago.

Did you get the Theile/Small parameters of the sx/xxx?

i can get 5.5-6 cubes will that work?

That depends on the T/S parameters of the driver, the amp and your goals.

im going to use 2 layers of mdf

Double thick MDF is always good.

all theed to brace it

Did you mean 'all thread'? That is not a good way to brace a box. Just go with window pane braces.

so i down fire and port the frount?

No one configuration is better than the other. Front fire both. Front fire the driver and down fire the port. Do whatever works for you.

should i go with a a single 6" or 2 4" ports

Which will give you slower port air speed? That's right, no T/S parameters so you can't figure that out.

what should i tune it to?

Did you figure out which amp you are going to use? Does it have a sub-sonic filter? Yes - tune right below the SSF. No - tune as low as possible.

By the way, you can pick up a keyboard with a working shift key at Wal-Mart for just a couple of dollars.

-Robert

Edited August 4, 200817 yr by Robert_J

right now the amp is going to be a bash 500 or oaudio 500. in my first post i said it's going to be used for 95% movies. im going to get ahold of scoot from fi but i think the spec's are the same as the fi audio ssd.

just to let you know right now i only have one arm thanks to a honda 400 dirt bike

right now the amp is going to be a bash 500 or oaudio 500. in my first post i said it's going to be used for 95% movies. im going to get ahold of scoot from fi but i think the spec's are the same as the fi audio ssd.

Do you mean Scott? As in Scott the owner? I'd go with the O Audio amp over the PE model. The PE has a fixed SSF at 30hz. Way too high for home theater use. The O Audio model has an adjustable SSF. If you use multiple ports you can basically clone what SVS does with their adjustable tuning subs.

just to let you know right now i only have one arm thanks to a honda 400 dirt bike

Right now as in healing and it will get better or right now as in you will be fitted with some sort of pirate hook?

-Robert

Yes Scott the owner.

Last year when i sent him my sub's to do the upgrade he said the se/xxx are the grandfather of the ssd and have just about the same spec. i read someplace about the ssf on the bash amp that's why i looked into the oaudio.

I'm about to go get fitted for my hook now, j/k i have to go to another doctors appointment

By the way, you can pick up a keyboard with a working shift key at Wal-Mart for just a couple of dollars.

this is what i got back from Scoot

"6 cuft after port and driver displacement using (2) 4" Aero port kits at full length. This would yield a nice solid response down to 20Hz and tune you to 22Hz. As most plate amps (assuming its a plate amp) have a slight boost at 25Hz followed by their subsonic filter kicking in after that it would work well. You can tune things lower if youd like, but you would be sacrificing output vs extension. If its with a plate amp I wouldnt do it as they roll off below 20 Hz"

The amp i plan to use is a Oaudio 500watt plate amp.

what do you guys think?

I think Scott knows what he's talking about

this is what i got back from Scoot

Still have a problem spelling Scott?

The amp i plan to use is a Oaudio 500watt plate amp.

The O Audio amp has a selectable SSF with frequencies of 25hz, 20hz, 16hz and 12hz. If you tune it to 22hz, then you want to use the 20hz SSF setting. Plug one port and you can set the SSF to 16hz for more extension. Similar to what SVS does with their tri-port system.

-Robert