Newbie with questions

[d_sinsley]

Ok so I have had surround sound for ever. However, I have always had cheap speakers and really didn't and still don't know what I am doing. I want to build all new speakers for my system. I want to build because I want to save money and get the best bang for my buck. More importantly I like to build and learn. So I will have lots of questions I am sure because I know nothing about the adventure I am setting out on. Here is my layout. I have a 13X13 room which is a multi-purpose room mainly for watching tv and movies but is not isolated from the rest of the house. The Tv sits in one corner and the sectional couch in an opposite corner. So the setup is diagonal across the room. I have a center channel that currently sits well above the TV but I will be redoing this area and want it just under the TV. Currently I use two older tower 3 way speakers for the fronts and two very small 4" speakers for the rear. I also have a 12" powered sub. I would like to replace all five surround speakers with matched speakers. I was thinking 2 ways. Let the sub be the sub and not have subs on the side speakers like I currently have. its about a 12 foot viewing distance to the TV. The fronts will sit on a shelf on either side of the TV and the rears will be wall mounted up by the ceiling. That's what I want in a nut shell.

Now my first set of questions is what size drivers should I use for the four side channels and for the center? I was thinking 5 1/4 or 6 1/2 for the woofer and a 1 1/8 dome tweeter. I have to balance money and quality. I can't afford the best. I saw on Parts Express a Kit using Dayton Audio shielded 6.5s for a $100.00 a pair sans the enclosure which is fine I want to build them anyway. and it had good reviews. This is my base line, I don't need to go with a kit but am ok with it. So what size drivers would be best to get the sound quality and not be real big enclosures? Is a single woofer and a tweet ok for the sides. And for the center should it be two woofers of equal size and a single tweet? Should all drivers be the same size?

This brings me to my next question. When building a ported box all the calculators ask for a resonant frequency (not fs). What little I know about this subject tells me this is the target frequency that I want to tune the box for. this is determined by port volume. In the kit above they are shooting for 45 hz. When pairing an enclosure and a driver how do you know what frequency to target? Say I want to build a box for 5 1/4 driver how do I know what number to feed into this slot so that it will compute the port dimensions? Also the kit above suggests a .5 cu ft ported enclosure however when I run it through a box calculator (2 different ones actually) I came up with a box size of .29 cu ft. I know smaller is not better but can an enclosure be bigger or does this change speaker dynamics? Especially for the rears size is an issue. I want as small an enclosure as feasible. When I ran the numbers on Daytons 5 1/4 driver the box size was more in the .4 range. So I am a bit confused on how to properly design the box and make sure I have it right.

The last question I have is the tweets are already sealed units so I assume they can be put into the same enclosure as the woofers without issue except that their volume must be figured in to account for their displacement. Is this correct thinking?

Ok that's enough for now, I look forward to the help.

Devon

 

[ski2xblack]

Speaker design is pretty complex, especially the whole passive network thing. Unless you are willing to go all the way down that rabbit hole, go with a full kit where everything from a design/engineering perspective has been done.

I haven't heard any of the Dayton/PE kits, but their forum is very helpful. Although not very active, Audioholics own DIY forum may have some ideas for you. Others catering to the diy kits that I've actually heard and can recommend would be GR Research.

Also consider your woodworking skills; if you're a novice cab builder there is a learning curve.

Regarding your room, I kind of like a diagonal layout. In our home it helps accommodate a multi-purpose room, and just so happens to be a good way to avoid strong early reflections with minimal treatments. I would suggest if at all possible to pull the couch out from the opposite corner-same orientation, just further from the walls. Treat the wall behind the couch. That should sound pretty good. The square room may be fighting you in the bass department, depending on how enclosed or open to other areas the room is.

 

[ImcLoud]

Speaker kits, loudspeaker design services, sub-woofers and amplifiers. and parts-express are great places to start... start with a kit like the tri trix and then build the center from scratch, then maybe some of the overnight sensations for surrounds...

 

[d_sinsley]

Thanks for the suggestions guys. I have no problem with the kit idea. As for building the enclosures, I assume that is what the cab is, I am very confident I can handle that task from a woodworking standpoint. I have built sub boxes for car stereos not to mention many many other things out of wood. Now the engineering is a different story. I think I have a good grasp on building the enclosures once I know the numbers I need to work with. The electrical end of the issue is a whole different ball game. The crossovers and what not are over my head. But I also love to learn. This is as much about learning how to do it as doing it. As for the GR kits I'll poke around and see what there is. The Dayton/PE kit is just a jumping off point for me. I am nowhere near committed. I liked the price, and the reviews. But am open to any and all suggestions. Especially before dropping the cash.

 

[ARES24]

I am going to second ImcLoud on this one, the tritrix build is highly recommended. (I am currently building a pair) It also doesn't cost too much and is simple to build (by comparison to some others). Putting together a crossover from a blueprint is easy, if you have to, youtube soldering. That's all it takes!