New L C R 1st time build need help.

[Ram Jr]

Hi All,

I am looking to start planning my new Left, Center and Right speaker build to replace my existing 3 on my 7.1 home theater system. Just this week I started to watch video's on you tube and I have a ton of questions that I am hoping can be answered with links to sites and video's to help me do my build. The overall dimensions of each speaker will be 20 W X 13 T X 10.5 D. These will have to work in a horizontal format. The Left and Right will be a 3 way set up with a 8in woffer mid and tweets not decided on yet. The Center will be a 4 way. I need input for what brand of devices are recommended on all 3 speakers. I think that I want a port in each of the speakers but is not necessary.

My plan in my head is to not do this using wood. :eek: I want to make it out of 3/4 acrylic or thinner. The front will be black and the back will be clear. I want to put some type thinner acrylic air channels inside the cab to help with the no insulation. (maybe.. reason why I say maybe is because if it wont work like this or sound hollow then I will make the whole project out of 3/4 black acrylic and have the insulation.) I might put in some LED's into the acrylic just for effect but nothing tacky looking like it should belong in a crappy honda or something. I would need to find out how to make it so the LED's turn on when the system turns on and it would be a soft yellow color nothing crazy.

Please let me know what you speakers will work out for me by providing a link through this site. I am still learning all the tech data on what ohms and hrtz blah blah blah. My biggest concern with this build is how to figure out all the internal electronics or the crossover part. All advise will be appreciated.

My 200 gal DIY fish tank is done now I can move over to my other hobby witch is home theater.

[Steve Henry]

Re: New L C R 1st time build need help.

The Speaker Project Gallery is for finished projects. Please ask the mods to move this to Tech Talk. You will get many more responses there.

[lunchmoney]

Re: New L C R 1st time build need help.

Were you planning on having any internal bracing in the cabinets?

If not, they'll probably be very resonant and not sound very good, particularly since you're using plastic, not a good material for damping sound.

If you do use internal bracing, then that could have a real impact on the aesthetics you're going for.

I'd think real hard about the logic of using acrylic, and whether it makes sense with the fundamental of good sounding cabinets.

[kmibb]

Re: New L C R 1st time build need help.

Acrylic might be a good idea with drivers that are 4" or less, but anything larger (and even some 4") are going to displace way too much air for reasonable cabinet coloration levels in an acrylic cabinet. You'll have to brace it, which will make the transparent part a lot less cool looking.

Also, if you don't have any experience building speakers and you want them to sound good, you need to build a proven design. There is a sticky in the forum for links to great designer's build pages. Wolf has a build that's almost exactly what you're talking about, the Tesseracts (sp?). Check out a lot of the stuff from Paul C, Lou C, Curt C, Wolf C and others.

http://m18.photobucket.com/albums/wo...ker/Tesseracts

[johnastockman]

Re: New L C R 1st time build need help.

Internal bracing is very important, unless the cabinets are small. Resonance is not something that you want in a speaker enclosure. Using plexi or acrylic will lead to a resonant cabinet without internal bracing. If this is your first project, Paul has a most-excellent write up here about doing your own DIY speakers:

http://sites.google.com/site/undefinition/diy


Read everything under "Resources" at the right of the page. If I would have had the advantage of that advice when I was trying to "DIY" my own speakers years ago, I could have saved a load of money and a huge amount of frustration wondering why what I was doing wasn't working. I was advised to try a proven design when I found this forum over 11 years ago. I built Wayne J.'s "Dayton Budget Project", a small 2-way. To say the DBP's were better than what I had built on my own was a major understatement. I knew the SQ from the speakers I had built were unacceptable, but those DBP's put it into perspective for me as what constitutes a well-designed speaker. I'm sure we can help you find a design that would work for you, maybe even with the cabinet ideas you have. I'm just a builder, not a designer, but I'm very glad I took the advice from the guys here when I did; as I was about to give up on DIY-ing my own speakers at that point because of the poor sound quality I was getting.


John A.

[Ram Jr]

Re: New L C R 1st time build need help.

Glad to see that people this early are starting to read my thread.

I was planning on having inner supports. I found this link on line.

http://speakerdesignworks.com/Statem...r_Channel.html
for the center

http://speakerdesignworks.com/Statements_Monitor.html
Left and Right

This is what I have found so far but can I build this to my LxWxHxD? And any chance I can make the woffer bigger for the Left and Right?

[kmibb]

Re: New L C R 1st time build need help.

Changing the Statement's dimensions is kind of a no no. Typically the only dimension that needs to stay the same is the baffle width, otherwise you'd need a crossover change. However, since the Statement series uses an open tunnel in the back, changing the length of the tunnel would also require a change in the crossover.

Also, substituting drivers in any design will almost always require a crossover change. All of the proven designs have crossovers specifically made for the drivers used and many other factors.

I strongly recommend against making any changes to a design that would require a crossover rework. However, if you find a design you like that doesn't use an open back mid, you can usually change the dimensions, aside from baffle width, to suit your needs. However, you have to maintain the same internal volume to avoid changing the bass tuning.

[kmibb]

Re: New L C R 1st time build need help.

Just FYI, the dimensions you gave yield an internal volume of 1.11 cu ft or 31.4 liters. Given that your mid will need its own small enclosure, you're left with about 1 cu ft to tune the woofer with. I'd look for designs that say they have a 1 cu ft (~30 liters) enclosure.

[dwigle]

Re: New L C R 1st time build need help.

Glad to see that people this early are starting to read my thread.

I was planning on having inner supports. I found this link on line.

http://speakerdesignworks.com/Statem...r_Channel.html
for the center

http://speakerdesignworks.com/Statements_Monitor.html
Left and Right

This is what I have found so far but can I build this to my LxWxHxD? And any chance I can make the woffer bigger for the Left and Right?

As suggested, read everything on http://sites.google.com/site/undefinition/diy.

Typically, you can't make changes to drivers, baffle width or enclosure volume without a re-design.

The designs you picked are very good but need to be constructed as designed. That said, if you're not particular about how they sound, you can make any change you want.

Pick a design with a following and build it as designed, you'll likely be very surprised at the quality. I wouldn't get hung up whether it's a 2, 3 or 4 way - it's kind of irrelevant, just a means to an end.

[Ram Jr]

Re: New L C R 1st time build need help.

Based on the above links that I posted can you provide a link to a kit that has a 1 cu ft 4 speaker enclouser for my center and a 1 cu ft 3 way system for the Left and Right?? I am kinda at a loss now.. :(

[kmibb]

Re: New L C R 1st time build need help.

http://sites.google.com/site/undefinition/swope-ht

Center channel is almost exactly what you asked for.

[Ram Jr]

Re: New L C R 1st time build need help.

Thank you for showing me the 5.1 build. I really like the center channel that he has. Do you think I can get away with building 3 of these and using them for my Left and Right as well?

I was reading his forum page on how he built them and I know the center channel was made for voice more so then music but would it be something that I could just adjust with my reciever?

[kmibb]

Re: New L C R 1st time build need help.

Thank you for showing me the 5.1 build. I really like the center channel that he has. Do you think I can get away with building 3 of these and using them for my Left and Right as well?

I was reading his forum page on how he built them and I know the center channel was made for voice more so then music but would it be something that I could just adjust with my reciever?

Not sure, PM or call Paul Carmody and ask.

[Paul Carmody]

Re: New L C R 1st time build need help.

Thank you for showing me the 5.1 build. I really like the center channel that he has. Do you think I can get away with building 3 of these and using them for my Left and Right as well?

I was reading his forum page on how he built them and I know the center channel was made for voice more so then music but would it be something that I could just adjust with my reciever?

Heyyy... You just might be in luck! I see from your location that you are in Plainfield. That's great. All we'd have to do is this: you build the cabinets, bring them to my house. I'll measure them, voice a crossover for you, and then you can have everything back. Shouldn't take me longer than a week. I'm in the Northwest suburbs, but still a drive over in your car beats "shipping and praying" any day... way cheaper, too. ;)

I've had several requests to do what you're attempting (LCR with the Swope Center Channel), but I've balked at all of them because I don't have the drivers nor the cabinets here anymore.

[kmibb]

Re: New L C R 1st time build need help.

Heyyy... You just might be in luck! I see from your location that you are in Plainfield. That's great. All we'd have to do is this: you build the cabinets, bring them to my house. I'll measure them, voice a crossover for you, and then you can have everything back. Shouldn't take me longer than a week. I'm in the Northwest suburbs, but still a drive over in your car beats "shipping and praying" any day... way cheaper, too. ;)

I've had several requests to do what you're attempting (LCR with the Swope Center Channel), but I've balked at all of them because I don't have the drivers nor the cabinets here anymore.

Doesn't get any cooler than that.