Help chosing a 5.1 design

[jgleadall]

Hi all, so i have been toying with the idea of building a 5.1 design for a while now. At first the TriTrix caught my eye, but after more reading the AviaTrix kit seemed to be more what i was after and fits reasonably within my budget considering the PE kit pricing. Does anybody have opinions about the Aviatrix, maybe some pros and cons or perhaps other designs that are in a similar range?

I was thinking a MLTL MTM for the fronts, an MTM for the center and MT's for the rears. I was also thinking of re-purposing a JL Audio 12w3 sub for the .1. For that i was looking at the Dayton Audio SPA250 250 Watt Subwoofer Amplifier for $119, seemed like a good value to me, does anybody have any experience with these? Or perhaps a better option?

Any opinions or advice would be greatly appreciated.

[ckmoore]

Re: Help chosing a 5.1 design

Budget?
Room size?

[NickJ]

Re: Help chosing a 5.1 design

Since you will likely want to cross over to your sub at about 80hz, you might not even need the TL version, and could probably go smaller and sealed. Then again, maybe you need to mains to go down deep for some reason. More info would be great. In addition to the previous questions, how loud do you want these things to be able to go?

[jgleadall]

Re: Help chosing a 5.1 design

These will be for both music and HT. they don't need to be super loud, but i would like them to fill the space with nice detailed sound, and room to grow in case i ever have a big party.

I was hoping to spend whatever the 2 and a half aviatrix kits were gonna cost, about $750 if i recall correctly. The room isnt big at all, about 10 ft wide by 20 ft long give or take, 8ft ceilings, hardwood floors. i will be sitting within 8 ft of them though. The space is kind of hard to explain, the room is sorta cut in half by a fireplace. My tv is mounted above it, so its more like a 10x8ish, 2 couches around it.

I kind of want the TL version more for the automatic height and standalone output. I would honestly prefer to not run a separate sub if these will put out reasonable bass, or perhaps cross the sub over real low like 50hz

[jgleadall]

Re: Help chosing a 5.1 design

Here, i just took a pic of the space to better explain what im talking about.


I was planning on putting a speaker on either side of the mantle and then the center above the tv

[jsr]

Re: Help chosing a 5.1 design

Paul Carmody has a nice HT design called the Swope. I believe someone had turned his MTM mains into towers also of you really want towers.

[[email protected]]

Re: Help chosing a 5.1 design

i have heard the aviatrix mtm in room your size. very sweet sound. while i agree you dont need the mltl for ht, you will for two channel. i like your plan alot. you might enjoy two subs though. one front, one rear.

[jgleadall]

Re: Help chosing a 5.1 design

Ok, well im glad to hear that, i think i will be happy with the aviatrix's, i always like to hear what others have to say though.

Two subs? that sounds a little greedy to me... maybe i will start with the one and see how that works. Does 250RMS watts sound like enough power? Ive had this sub(JL Audio 12w3 ) running in a car for years and there was always loads of bass.

Ultimately i would like to complete the mains first anyways, im in no rush for bass.

Now, on to my next question. For the sub i will obviously use 3/4" MDF, but what i would like to know is if there's any advantage to using 3/4" Baltic birch for the other boxes compared to MDF? I would really like to do everything i can do make these sound the best i can.

[saabracer23]

Re: Help chosing a 5.1 design

Well in a car you have lots of cabin gain, very little volume to pressurize. But who knows you may be happy with one 12. The Baltic is going to be lighter and size for size the Baltic is going to be stronger than the mdf. Also the baltic will be less mess when cutting and the like (mdf dust is no fun). Mdf is a "dead" material though and cheaper so that's why it is so popular.

Dan

[tashspop]

Re: Help chosing a 5.1 design

Paul Carmody has a nice HT design called the Swope. I believe someone had turned his MTM mains into towers also of you really want towers.

this is the direction i have chosen for my build. i've got the center done and its great. paul has just recently chose to match up some tmww so voiced options in the swope setup is wtmw,tmww, mtm, and tm. lots of options.

[TommyRocker]

Re: Help chosing a 5.1 design

Another vote for the Swopes. I built just the fronts as my first build and they sound great. I find that I've been listening to most things in stereo because the rest of my speakers just sound dead compared to the Swope MTM's. I can't wait to build the center and surrounds.

[johnastockman]

Re: Help chosing a 5.1 design

These will be for both music and HT. they don't need to be super loud, but i would like them to fill the space with nice detailed sound, and room to grow in case i ever have a big party.

I was hoping to spend whatever the 2 and a half aviatrix kits were gonna cost, about $750 if i recall correctly. The room isnt big at all, about 10 ft wide by 20 ft long give or take, 8ft ceilings, hardwood floors. i will be sitting within 8 ft of them though. The space is kind of hard to explain, the room is sorta cut in half by a fireplace. My tv is mounted above it, so its more like a 10x8ish, 2 couches around it.

I kind of want the TL version more for the automatic height and standalone output. I would honestly prefer to not run a separate sub if these will put out reasonable bass, or perhaps cross the sub over real low like 50hz

The pic you posted didn't show up, but if you want the system to perform adequately for the LFE's in movies, you'll need the sub for the uber-low stuff. Most HT receivers now have good bass management. Still, a cross-point from the sub to the front mains around 60-80Hz is a good place to keep the sub out of the "localization" frequencies...the point where you can start to tell where the sub is at in the room. Just general rules 'o thumb, as the room can contribute negatively or positively, to the overall SQ of the low frequencies. That's why one of the guys suggested 2 subs, as that can help with room nodes and the uneven distribution of the low end. BB plywood is a good material for the sub. If the JL is a pretty stout/heavy driver, you might want a double-thick front baffle for mounting the driver...just sandwich 2 pieces of 3/4" material together for 1.5" thickness. Get the T/S parameters for the JL and use either WinISD:

http://www.linearteam.dk/default.aspx?pageid=winisd

Or Unibox:

http://www.pvconsultants.com/audio/boxmodel/unibox.htm

With the T/S numbers, you can get an appropriate cabinet design/volume so the JL will work well in the home environment. Some drivers are more suited for a sealed app, some for a ported enclosure. Those easy programs can help you determine what would be best. Make sure you internally brace your sub cabinet. Very important. You can find examples of internal bracing that the guys here have implemented. Nothing fancy, just a couple side-to-side, top-to-bottom and if possible, front-to-back. The bracing is where store-bought subs fail...I've seen way too many popular name-brand subwoofers that have no bracing at all. If you need help with the enclosure for the JL driver, we can help with that. The Avia's are very nice, so is the Swope design that was mentioned. Either choice will net you something that will be quite a ways above the SQ and listening enjoyment of retail offerings for less money.


John A.

[jgleadall]

Re: Help chosing a 5.1 design

There we go, got the pic fixed, Im still figuring out how to host images with my gmail account. excuse the pic, i just took it on my phone last night without too much light.

So what your trying to say is that sub placement IS important? hrmm... i was just planning on hiding it below my components which is just behind the fireplace. Maybe having it closer to the couches would be a better idea? How about the direction the driver is facing? does that make much of a difference? i was thinking down firing would be better so i wouldn't have to worry about a grill, but i noticed most kits aren't.

I already loaded up the specs into WinISD a few hours ago and im trying to figure out where to go with all of this. it recommends a 5.6cu ft enclosure tuned to 22.54Hz for flat response, seems a little excessive to me. When i had this in my car it was in the JL recommended enclosure which is 1.75cu ft tuned to about 32Hz.

which would be more desirable?

[jsr]

Re: Help chosing a 5.1 design

Yes, room placement for subs make a huge difference. People do whats called the sub crawl where they inch the sub across the entire floor. Sub placement affects the frequencies that will get reinforced from room gain. For me, luckily (in terms of saving time), I had limited options for placement but I did put the sub in various areas that I could too see which was best.
You should consider multiple subs. It's not for more volume that most people think, but for more equal coverage across the room. If you have multiples though, you have to play with phase to make sure theyre not canceling each other out.
For your response sims, go for the one that extends lower. The reason JLs recommendation doesn't go as low is because most music doesn't have much content below 40hz. Also, the reinforcement frequencies in a car also tend to be higher and add to the 40-60hz range. For home, movies have alot of very low frequency content, so you want the sub to extend as low as possible without generating too much distortion.
It doesn't matter the subs orientation. Baas frequencies are omni directional. Lower cost commercial subs are down firing because it costs less to make without a grill. However, you can get a BIC F12 for under $200 shipped, and those are great performers. There are several sub-$200 or near subs that preform great for HT, though there are better ones for music.