08: Home Theater Project Beginning (2 Viewers)

[God_Speed351]

Yeah I have been looking around their site for a few days. Thanks anyway though.

 

[Robert_J]

An IB is really just a very large, sealed box. So large that the enclosure has no effect on the performance of the driver. No coloration of sound (good) and no air acting as suspension (sometimes bad). They will easily play down into the single digits. To get a conventional sub to do that it would have to be the size of a refrigerator. And yes, there are guys building them this size.

The only downsize to an IB is output. Since there is nothing stopping it from playing so low, we can only power it based on single digit extension. For example, a ported enclosure tuned to 20hz can play at 110db. The ported sub has a filter at 20hz to keep from playing anything below that. Because an IB can play down to 10hz, we have to look at driver excursion. If a conventional sub moved 10mm at 20hz when driven by 200w, it will move 40mm at 10hz. It takes 4 times the excursion to play the same level one octave lower. Can you find subs with 40mm of excursion? Yes. There's a nice 18" model from resonant engineering that costs $1,300. To make up for the lower output, we use multiple drivers. Basically, the more cone area you have the less you have to push your subs to reach your desired levels. The less excursion the less distortion you have. Basically, you can't have enough cone area.

Like JJ's install, a manifold will with opposing drivers will cancel out mechanical vibrations. When testing my 18's, I can't hold them still when pushing less than 100w to them. It's like holding a jackhammer. That's why you will see most IB's with an even number of drivers.

Fi Car Audio has 15" and 18" drivers designed for home IB use. They aren't on the web site so you have to e-mail Scott for details. I may have linked to the Home Theater Shack thread about them. Besides Fi, AE Speakers has 15" drivers. Parts Express has the Dayton line with 12" and 15" IB drivers. They were nice when they were first introduced but now there are much better drivers out.

-Robert

 

[God_Speed351]

You did link the Fi drivers and thank you. I guess I need to do some persuading the the wife on how much better it would sound/feel with an IB and opposed to a traditional. Plus I could free up some floor space

 

[Robert_J]

Freeing up floor space and getting rid of a huge, ugly box has WAF written all over it. And patching drywall takes less than an hour of work time.

-Robert

 

[God_Speed351]

Yeah,. I'll let everyone know how tonights "negotatiions" go.

 

[God_Speed351]

Well the "negotiations" went ok. I think I almost have her convinced that it would be a better option to have a IB than a traditional sub sitting in the floor. I am posting a pic of out living room(just ignore the clutter). The wall behind the tv is a shared wall between the living room and a oversized 2 car garage. Now my question is would I be able to mount an IB sub on this wall?

On either side of the TV. It is also an option to turn the shelves with the books and DVD's so that they sit facing the TV so I could mount an IB in the corner to the far right. If I do the IB then the small pioneer sub and PC will be removed from the area to the right side of the tv. The small corner shelf beside the PC is also on its way out. It kinda just got stuck there, and had some flowers put on top of it.

Get two of the FIiCarAudio 15's or 18's and the amp from Guitar center That will put the price around $507(15's) to $667(18's) Plus materials for the enclosure.

 

[Robert_J]

If there is a garage behind that wall, then you can install an IB. Check out Cult of the Infinitely Baffled for dozens of different manifold designs. And I'd go with the 18's over the 15's any day.

-Robert

 

[God_Speed351]

I have a thread over at Cult of the IB about my IB setup. I have been looking at these speakers to go with the Onkyo 705 or 805 receiver Onkyo SKS-HT540 - 7.1-Channel Home Theater Speaker System | Model Information | Onkyo USA Home Theater Products]http://www.onkyousa.com/model.cfm?m=...eater Products I know it comes with a powered sub but I could always put an IB in the front and run the traditional sub behind the couch.

 

[Robert_J]

The powered sub in that setup would only add distortion to your IB. I wouldn't use it. In fact, I wouldn't buy a package set like that. You are stepping into world class bass but going cheap on the speakers. Upgrade in stages and get quality speakers. AV123, SVS and Elemental designs all have nice speakers that you could use as your front 3.

-Robert

 

[JJMJ71]

Chuck,
How much are you willing to spend on speakers for the HT room? Do you have an idea of a brand of speakers that you would like to have at some point in time if you were to upgrade? If so and the budget is minimal I would at least invest some money on a good center channel and mains at Robert mentioned. If you do not have that much then at least get a good center channel since the center is one of the most used speakers out of the 5.1 system. Then you can eventually buy mains and then the surrounds. Then you could eventually use the onkyo speakers for the room upstairs.

Cheers,
JJ

 

[God_Speed351]

I looked at those speakers. I like the Elemental Designs prices(budget friendly) If I got the A6-6T6(200w) for my center and the A6-5T5(150w) the the Front L and R I would still be within my budget on things to get now assuming I could use my kenwood speakers now for the Left, Right, And rear surrounds in a 7. setup.

All this equipment will be installed in the upstairs living area for the time being and then when the basement is finished I will move the Receiver, Speakers, Blu-Ray player, and Build a new IB sub. The Speaker wire is run under baseboards now for a 5.1 setup so I will add 2 more wires for the 2 more channels which will be run using the wall channels which can be moved if I wish to later.

I will be adding a 56" or 61" 1080p DLP Samsung with the LED light engine upstairs and selling the 720p Samsung DLP that is there now.

 

[Robert_J]

ED even runs their own forum (icixsound.com) where you can ask detailed questions. About half of the time, the owner of the company is answering the questions. Other than AV123 and SVS, I know of no other company where you can get that kind of service.

You can absolutely use the Kenwoods for surrounds. I'm using older Polks as my surrounds. One even has a busted tweeter. They are temporary until I can build 7 identical speakers. Now that I have time to build, the temp has dropped below the minimum recommended by my wood glue manufacturer.

-Robert

 

[God_Speed351]

So you are going to build all your speakers?

Do you have any opinions on the TV's I listed?
circuitcity.com- Product Comparison - Projection TVs

 

[Robert_J]

Yes, I'm building all of my speakers. Six of the mid-tweeter-mid and one of the center channel using the Dayton home theater plans. Build my subs as well. Literally. I bought the magnets, frames, cones, etc. Bolting and gluing up four 18's.

Out of those TV's get the biggest. Don't pay any attention to how they look in the store. Once home and calibrated, they will all look great.

-Robert

 

[God_Speed351]

Would LED lights offer anything extra except for longevity? I will have to take a look at those plans.

 

[God_Speed351]

What are some opinions of the AE15 vs the FiCar Audio 15's vs FI 18's.
So

(a) 2 FiCar Audio with ep-2500 $488(est)
(b) 2 FiCar Audio 18's with ep-2500 $650(est)
(c) 4 AE15's with ep-2500 $650(est.)
(d) 4 FiCar Audio 15's with ep-2500 $726(est)

in a 17'5" x 14'8" x 8'(celings) Room.

 

[Robert_J]

Design and quality between the two companies is a wash. Scott Atwell at Fi is a great transducer engineer as well as John J. at AE. John's business is a little smaller. Scott not only builds drivers for Fi, the builds them for Ascendant Audio, Epik Subwoofers and I think Sound Solutions Audio.

For actual performance, we need to look at the displacemnt of the drivers. Take the piston surface area of the cone (the Sd parameter) and multiply it times the xmax (in cm) times 2. Then multiply that times the number of drivers. Divide by 1,000 and that gives you the liters of air the proposed sub system will be able to move.

You can also look at the other T/S parameters. The lower the driver's Fs, the easier it is to for the sub to play low. Not always a big issue with EQ available. Also, the Qts should be a little higher for IB subs. .500 is perfect. But again, that's debatable. I'd go down to price vs. having a 2 driver IB or a 4 driver IB. I thought about having a 4 driver manifold but determined that I would have to build it in my attic. I switched to a having a pair of dual driver manifolds that I can easily get through the attic door. I will still install the drivers while in the attic. I don't think I can carry an 80 pound manifold with 80 pounds of drivers installed without bumping into something and breaking it (the bumpee, not the sub).

I did some calculations and the 18" Fi will potentially move twice as much air as the 15" Fi. I would go with a pair of the 18" Fi subs and wire them in series to one channel of your EP-2500 for a 4 ohm load. If that isn't enough, then get another pair of 18's for the other channel of the amp.

-Robert

 

[God_Speed351]

Thats the entire reason I am here.
Now I have another question. Would it be possible to do the following. using 2 18's to start and then adding 2 more in a few months? Or would it simply not work or sound like crap. I could always add a center wall to divide the box into 2 smaller boxes until I added the other subs.

 

[Robert_J]

That would absolutely work. Go ahead and cut the holes for the drivers and mount in MDF discs in the place of the future subs. Make sure you use closed cell weatherstripping for an air tight seal.

If you were local, you could have my manifold for 15's in the pic below. I was testing it to make sure it didn't vibrate and make any noise.

-Robert

 

[God_Speed351]

Thats good news, I'm going to start an actual "list" of parts I need for the initial build now. Building a box for 4 18's but will only have 2 to start.

I am guessing I will need a least 40" High x 16" Wide x 20-21" deep box for the subs with some support in the middle. And how well will an ep-2500 power 4 Fi 18's?