[pete in atlanta]

Greetings All-
I'm new to the forum and home theater, I've spent no less than 5 hours paroozing the forum and have found some fantastic subs. I'm looking for a tried and true, totally stable and proven performer for around $500.I already have multiple sheets of MDF so the box materials don't have to be factored into my budget.

I want base that is palpable. When the soundtrack has thunder, I want to feel the thunder. When a cannon goes off, I want my guests to run for cover.

I'm totally new so Im looking for a complete shopping list (and where to buy), drawings and instructions. I can build a box but the rest is all black magic to me at this point.


About my space:
I've built out my theater with Klipsch reference inwall speakers and am using a Yamaha RX-V665 receiver. The inwalls are really nice but as expected, need a good bit of help in the bottom end.
The room is roughly 20 X 15. It's a bonus room over my garage so the ceiling is angled along the longer walls. front stage is along one of the long walls (with the angled ceiling).

Thanks in advance for your help, patience and guidance.
-P

 

[Mike P.]

When a cannon goes off, I want my guests to run for cover.

You're talking a big ported enclosure. Do you have a box size limit or does anything go?

The best I can think of in that price range is a Dayton TIT400C-4 15" Titanic Mk III Subwoofer $219.88:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-420

with a Dayton HPSA500 500W Subwoofer Amplifier $250.00:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-806

and a pair of Precision Port 4" Flared Ports $13.90 each:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=268-352

With shipping it will be a bit over $500.

The sub in 11 cu.ft. tuned to 18 hz would work well.

 

[pete in atlanta]

Thanks Mike-

According to my wife...
...size does not matter

LOL

Actually I don't care about size. Would this work?
I have a closet in the front left hand corner of the room- just to the left of the front stage.
I was thinking that I could place the sub in the closet and cut a hole in the door and cover it with a grill.

I am really not a fan of having any equipment show in the room but if this wont work, I'll live with it.

We're not planning on staying in our current house much longer or I'd build something into the back wall. Theres a crawl space back there and it would be pretty easy to hack out a stud or two and build a tunnel for the sub. But since we're movin, I don't want to have to do any drywall work.

Are there any good plans for the setup you listed?

 

[Mike P.]

As long as the sub is right up against the door it should work. As for plans, the sub dimensions will depend on what width of cabinet will fit through the door.

 

[pete in atlanta]

it's a 32 inch door so we're pretty good size wise.

 

[Mike P.]

What's the depth of the closet from the inside of the door to the back wall?

 

[pete in atlanta]

depth of closet is 24"
Usable length of closet is 64"

 

[Mike P.]

Build a box that has external dimensions of 28" wide, 37" tall and 23" deep. Add a couple of "window pane braces" and you're good to go.

 

[pete in atlanta]

So far that's great Mike:
My apologies for green horn questions:

Does it matter where the sub sits in the room?
I'm thinking that I could also stick the sub behind the long sectional we're putting on the back wall or make it into a side table if I make the enclosure really deep.

Do the box dimensions matter past the overall volume of the enclosure?
Is it better to have a wide, tall or deep enclosure?
Do your dimensions include a double layer front?
Where do the ports go? Does it matter?
For the window supports, how much material should I remove?
Does the amp take care of the cossover stuff?
Do I need to do anything but plug the amp into the speaker and fire it up?

 

[hddummy]

End table builds are a perfectly valid option. Many have built fantastic looking "Furniture Subs". Room placement is a tricky thing, however, and should be evaluated for each individual situation. Do you have another sub or one that you can borrow to do some testing before you build your own? If you do the "crawl" test for your two proposed locations, it would help decide which of the two will give you the best sound response. Basically, you put a subwoofer on the couch were you mainly sit then listen to a movie or music with your head where you propose to put the sub.

Overall volume is obviously most important, but individual dimensions matter too. Generally, you should try to stay below 36" on any inside dimension. Anything higher can result in resonance frequencies that could color or accentuate certain frequencies.

If you do the closet idea, you would likely want the port on the front face with the speaker. The general rule of thumb is to keep the edge of inside port opening at least one port diameter from the inside face of the box walls.

I think you should be similar in concept to this build for box configuration and bracing.
http://www.hometheatershack.com/forums/diy-subwoofers-sealed-ported/18149-jon-fs-dual-9-8-ft3-css-sdx15-ported-box-build.html

The AV receiver will handle all of the crossover from the main speakers to the sub. THe sub will still require a High Pass sub sonic filter. The amp should have one built in and MikeP is good about accounting for those. Another really good alternative is the 500W amp by O-Audio as it has some filter adjustment and equalizer features built in.

Building a sub is really a plug and play project. Oversimplified: build the box, install some sound absorbing material, install the port, install the speaker, connect speaker to amp, install amp, connect amp to AV Receiver, test and tune sub, enjoy movie.

 

[Mike P.]

Thanks Matt for joining in!

Do your dimensions include a double layer front?

No, box dimensions stated were based on a single layer.

 

[pete in atlanta]

thats a smart looking sub design Matt. Perhaps I just need to get over my stigma with the big box in the room and build a traditional box first. If it drives me crazy, I'll try the closet idea.

Would that be the correct size for the woofer that Mike suggested? Seems Mikes sub has around 11 cubic feet minus bracing while the other enclosure is around 9 cubic feet.

I'm kinda looking for a plan that has been built many times so, has a cut list, and all instructions and all the issues already been ironed out. Can't seem to find it yet.

Coupla questions:
1) what should the receiver crossover be set at. I just checked and it's currently defaulted to 120.
2) For the plate amp- do I need to build a box inside the enclosure for the plate am or just cut a hole for it to fit?
3) Port length- Mike mentioned two four inch ports. How long should they be? Can I use a single six inch port instead like the plan you linked to? Are there advantage to multi / single port?


My pal is heading out of town on Thursday and loaning me his velodyne sub to test the room with. I dunno the model yet but he's got a similar sized room and says its more then enough.

Thanks for all the help guys- I'm learning alot.

 

[DragonArt]

1: Depending on your main speakers, it should be set between 30 and 80hz. Anything above that and the subs will start to localize.

2: Depends on your plate amp, but it is generally a good idea.

3: Use WinISD to calculate, it is really simple to use.

 

[Mike P.]

The Titanic sub is in 11 cu.ft. net volume, the bracing, sub and port displacement need to be added to that. There is a volume calculator here that makes box design easy.

http://www.hometheatershack.com/forums/enclosure-volume-calculator/

 

[pete in atlanta]

new plan- same price considerations but saw this and it would be prefeect:

http://forum.edesignaudio.com/picture.php?albumid=94&pictureid=955

these are sealed but I'm thinking that I could make a ported enclosure and slide it behind the main seating area of the couch.
What do yall think?

 

[Mike P.]

Same setup as shown, dual subs? Do you have a driver picked out?

 

[hddummy]

what kind of box dimensions can fit behind your couch?

 

[fredm]

Just to jump in:

The Dayton amp that Mike P. said would not be my first choice. It's big brother tested out horrible. The O-Audio Bash 500W amp is cheaper and tests out great

http://www.oaudio.com/500W_SUBAMP.html

 

[Mike P.]

It's big brother tested out horrible

The test done on the HPA1000-rack mount amp was done with a fully resistive load bank. No sub in the world offers any amp a fully resistive load. As stated by Rich Taylor from Dayton Audio:

I'd like to say I’m concerned by some here that immediately assume this amplifier is “bad”, especially in light of the fact that this is a tracking amplifier that's designed to deliver high voltage into reactive loads (ie, loudspeakers). They are not optimized for fully resistive load banks. So much of this talk in this thread is not relevant to driving woofers. These hi-tech amps can put a ton of power into the actual woofer and cannot be fully tested using standard non-inductive resistant loads.

Lots of people are using the 500 and 1000 watt Dayton amps with no problems. The 1000 watt plate amp version was tested on SSA and it made it's rated power output.

 

[pete in atlanta]

OK- dimensions behind couch could be:

H: 30"
D: 28"
W: anything- we have 19 feet of fall here.

So for the driver, I was thinking I would stay with the configuration that Mike P had laid out:
-Dyton TIT400C-4 15" Titanic Mk III Subwoofer
-Dayton HPSA500 500W Subwoofer Amplifier

I did a search on behind couch, wedge, hidden and couldn't find anything but the gigantic wedge that
Sonnie built:
http://www.hometheatershack.com/forums/soundsplinter/3519-dual-rl-p15-d2-llt-sub-project.html

I'm uh... looking for something a bit less substantial