Please help with design issues for home theater

[bluesboyjr]

This is my first post, and I would first like to thank everyone for the valuable information that I have already read on this forum, and I would like to ask for advanced forgiveness of my igorance on some of the subject matter. But, we all have to start somewhere, so here I go.
This is going to be my first project, and I am open to whatever ideas you guys can throw at me. I'm not stuck on a certain speaker, design, or anything, all I want is a set of speakers that sound good and are the best bang for the buck in my budget. I know these type of design questions have been asked hundreds of times by noob's, and I have read what I could find and just can't figure out what will work best for my room situation.

MY OBJECTIVES:

design: I would prefer a tried and true design over my own
design

# of speakers: 3 (left front, center, right front) eventually I would
like to add a sub, unless it is not needed

speaker configuration: open to ideas

budget: under $500

primary usage: 100% movies, 0% music

goals: I currently have a $500 sony htib, which to my tastes
could be a little bit louder and I have much trouble
discerning dialogue on movies (possibly b/c of the shape
of my room?) So, I would like to improve on these areas.

TECHNICAL DATA:

receiver: possibly either a yamaha htr5760 or a pioneer
vsx1014tx-k (I haven't ordered one yet, but these are
my top two choices because of their auto-calibration)

speaker location: all three speakers, will go behind my projector
screen (I plan on using either a screen research
or a da-lite high contrast cinema perf (both are
"acoustically transparent"))
They must fit in a space that is 27"h x 52"w, I
am somewhat flexible on the depth, but would
prefer to be under 12" (again, I am somewhat
flexible)

room size: I will post some pics with descriptions of my room
later in this post, but my total cubic volume
(including adjacent hallways and kitchen) is
approximately 5600 cu ft

main listening area: the area that will be sat in most is 12' away
from the speakers and the center of the
27"h opening is approximately 20" above
ear level



ROOM

PIC #1: http://us.f1f.yahoofs.com/bc/51a455c3/bc/My+Photos/room1.jpg?bfouqpBBH4.m4DQI

This is a side shot of the room from the kitchen side, you can see the open hallway the vaulted ceiling and the hardwood floor

PIC #2
http://us.f1f.yahoofs.com/bc/51a455c3/bc/My+Photos/room2.jpg?bfouqpBBUTXnOMM7

This is a shot from the screen side of the room, here you can see the odd shape of the room and the plant shelf in the upper right hand corner, along with another open hallway

PIC #3
http://us.f1f.yahoofs.com/bc/51a455c3/bc/My+Photos/room3.jpg?bfYBrpBBdHXEKFn8

Here is a shot showing the kitchen side of the room

PIC #4
http://us.f1f.yahoofs.com/bc/51a455c3/bc/My+Photos/room4.jpg?bfYBrpBBUzlq8DnM

This is the shot of where the screen and speakers will be going, there is also a mantle and fireplace I'm getting ready to put in, which will go under the screen



Well, I think I've given enough info to get started, let me know if I've left anything out. Just to let you know I have some decent experience in woodworking (not extensive, but I'm willing to give anything a try) and I am a residential electrician so reading schematics should not be a problem, and if I have any trouble putting parts together, my dad was a stereo repair guy for a few years way back, so he should be able to help me. Thanks again.

 

[LaMa]

Try full range tangband speakers for the center channel it doesn't cost too much. For your front speakers I suggest to go with some tangband Dayton hybrid. e.g. Dayton reference 8" for the bass and tangband for highs. In that case you have the same sound signature for all and true bass performance as a bonus.

You can put the dayton in a 60-70 l cabinet tuned at 22-25 Hz. Cross-over at 300-800 Hz with a tangband unit. Price indication ~$45/each

For the proper tangband unit I would suggest the W3-871S (the one with the metal cone). Price indication ~$25/each

Just a suggestion, if you want more extension on top you need to add a tweeter, but with the 3" TB I doubt it..

 

[AndrewT]

Hi, plan for 5.1 channel and include for future rear left & right as well as sub.
I have seen recommended that all speakers should be full range and not just satellites. This also implies that the peak volume from each speaker should be about the same. This applies especially to dolby surround sound (movies) because the loud bits could come from anywhere.
& for best movie sound effect the sub bass should go really low, aim for an octave below music i.e. about 20Hz to 30Hz or lower if quality and budget permit.
From your listening distance it appears that the stereo separation is too narrow. Try; listening distance = left & right distance.
If your decoder cannot cope with time delays then also try to keep listening distance to all speakers about equal.
regards Andrew T.

 

[bluesboyjr]

Try full range tangband speakers for the center channel it doesn't cost too much. For your front speakers I suggest to go with some tangband Dayton hybrid. e.g. Dayton reference 8" for the bass and tangband for highs. In that case you have the same sound signature for all and true bass performance as a bonus.

Thanks for the reply, do you know of any established plans that use this set-up and have the design and XO mapped out, b/c I do not own any testing software and I want my first project to be a proven design, so I don't get frustrated building the XO. Sometime in the future, if this project goes well, I may try designing my own.

You can put the dayton in a 60-70 l cabinet tuned at 22-25 Hz. Cross-over at 300-800 Hz with a tangband unit. Price indication ~$45/each

What are you referring to when you say tune the cabinet at 22-25 Hz?

For the proper tangband unit I would suggest the W3-871S (the one with the metal cone). Price indication ~$25/each.

I checked up a little bit on this 3" and people seem to be pretty happy, but some have noted a peaking at 17 Khz. Have you noticed this and would it affect me much since I'm using it for ht and not music?

From your listening distance it appears that the stereo separation is too narrow. Try; listening distance = left & right distance.
If your decoder cannot cope with time delays then also try to keep listening distance to all speakers about equal.
regards Andrew T.

Thanks for replying, I probably will plan for a 5.1 set-up, but monetary funds are limiting me to just the three speakers for now. As far as the listening distance to the speaker seperation ratio goes, I'm pretty much stuck with what I have to work with, and I'm hoping that the auto-calibration of the receiver will help with this. If I am way off with my assumption, please let me know.

 

[bluesboyjr]

Any suggestions? Please help!

I forgot to mention in my original post that the speakers will be surrounded by sheetrock on the front, back, and sides. I can leave up to a couple of inches on the top and sides if I need to, but I'm assuming I need a sealed enclosure since there is not much room for venting.

Thanks so far for the help, but please, keep it coming.

 

[Bill Fitzpatrick]

I have tried several times without success to see the pics but only get an error message. Have others had a problem?

 

[bluesboyjr]

Sorry Bill and everyone else, I forgot to make the folder public, so nobody could see it but me. It should be fixed now, so let me know if you are still having trouble. Thanks.

And regarding my last post about the sheetrock, I said that wrong. The sheetrock will be in close proximity to the top, back, and sides, not the front, that would be senseless.

 

[johninCR]

First, will the fireplace be used? I don't know about a projection screen above a fire place.

Second, is the screen permanent or will it retract or roll up? Does it have to be flush with the wall or can it be out from the wall a foot or so?

Third, what kind of movies do you like to watch and how loud to you want it to go?

Get me these answers and I'll give you some different options. In the meantime, just forget about any boxes to build. Boxes is the main reason you can't understand the dialogue with what you have now.

 

[Bill Fitzpatrick]

Still no pix.

 

[Bill Fitzpatrick]

Boxes is the main reason you can't understand the dialogue with what you have now.

That's a load.

 

[bluesboyjr]

First, will the fireplace be used? I don't know about a projection screen above a fire place.

Yes, the fireplace will get used, but the mantle extends 12" away from the wall, so it should re-direct most of the heat. If necessary I will wire up a blower to re-direct even more heat.

Second, is the screen permanent or will it retract or roll up? Does it have to be flush with the wall or can it be out from the wall a foot or so?

It will be a fixed screen, that will be flush with the wall.

Third, what kind of movies do you like to watch and how loud to you want it to go?

I prefer movies such as Blade, LOtR, mostly highly visual movies, whereas my wife is more of the girly-movie type.

 

[bluesboyjr]

Sorry again about the pics, Bill, this is my first time trying to post pictures on the net. I'll try re-posting the url's now that I have made the file public.

Pic #1: http://us.f1.yahoofs.com/bc/51a455c3/bc/room+pics/room1.jpg?BC7KCqBBnrpZ.Xj2

Pic #2: http://us.f1.yahoofs.com/bc/51a455c3/bc/room+pics/room2.jpg?BC7KCqBB_63oV9DC

Pic #3:
http://us.f1.yahoofs.com/bc/51a455c3/bc/room+pics/room3.jpg?BC7KCqBBQAjaF3cE

Pic #4: http://us.f1.yahoofs.com/bc/51a455c3/bc/room+pics/room4.jpg?BC7KCqBBvzGa.6_5

 

[bluesboyjr]

Well, I checked on my wife's computer and it looks like the pics are up now. So, now that everyone can see them, please don't jive on me for my temporary wiring job. I've already heard enough from my dad (who is also my boss) came over to see the house.

 

[johninCR]

Is that a door or a window to the right of your screen?

What's behind the screen? If you just cut this 27x52 hole you are talking about is air volume up above that or is 27x52x12 all the airspace available?

 

[bluesboyjr]

Is that a door or a window to the right of your screen?

It is a window.

What's behind the screen? If you just cut this 27x52 hole you are talking about is air volume up above that or is 27x52x12 all the airspace available?

Well, technically, by our local building codes I need sheetrock seperating the chimney duct from the living area for fire reasons, but since I am doing it myself I could allow for some venting into the chimney chase which would give me more usable airspace. This would be only at the backside of the speaker, but the top could also be done, minus 4 1/2 in for the header and existing sheetrock.

 

[Bill Fitzpatrick]

Still no pics.

 

[johninCR]

First let me say that for a real cinema like experience that audio is almost as important as the video. Whatever receiver you get is going to be at least 5.1 capable, or you don't want it. You need 5 speakers and a sub, not just 3 speakers. If you insist on them being behind the screen, then a center channel speaker isn't really necessary.

A better option is a center channel behind the screen and 2 front left and right speakers off to the side. This will make the sounds that pan from left to right, etc. more realistic. It will also enable you to use open baffle speakers which will give you more natural and clear dialogue and the sound is much more open instead of sounding like it is coming from inside a box. There are some nice 8" pioneer drivers that work well on OB for only $25 each, so $125 plus shipping for 5 and you'll have money left for a sub and subwoofer amp. http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=290-045. You'll just have some limited wood and supplies to buy. The only real drawback with open baffle is that getting bass is more difficult, but that's what your sub is for.

If you really want them only behind your screen, then just use 2 of the same driver, cut a hole in the sheetrock for each out near the left and right edges of your screen as low as makes sense since your screen is elevated. This will work well as what is called infinite baffle if there is a good bit more airspace behind the sheetrock and it doesn't get hot in there. It works well because the speaker cone is allowed to move freely without the pressures inside a box, but it won't have the open sound of OB.

For the subwoofer, from the pictures it looks like some of the walls have an attic on the other side of the wall. That's where the sub will go in an infinite baffle setup. Don't worry you won't even know that's where it is because sound waves below 100hz or so are omnidirectional and that's all the sub will play. You'll set the distance to you for each speaker in your receiver, so all the sounds get to your ears at the proper time.

Now to make an open baffle believer out of you. Bill's still a non-believer. Take the drivers out of one of your existing speakers. If there's more than one set of wires make note of which goes where. Get a piece of cardboard. It doesn't have to be big, but the bigger the more bass you'll have. Cut holes with a seraded knife for the drivers and use duct tape around the edges to hold them in place on the cardboard. Reconnect the wires from inside the old box (you'll need some extra wire for this) Tape up any exposed bare wire so you don't blow your receiver. Then give it a listen along with your other speaker. It won't have the same amount of bass, but you'll hear that it sounds more open and natural than before and the other will sound like what it is....just sound coming out of a box.

If it looks difficult to get the drivers out and you don't want to destroy the box trying, just go down to the local thrift store and buy the cheapest pair you can find that looks like it would be easy to get the drivers out.

 

[bluesboyjr]

First let me say that for a real cinema like experience that audio is almost as important as the video. Whatever receiver you get is going to be at least 5.1 capable, or you don't want it. You need 5 speakers and a sub, not just 3 speakers. If you insist on them being behind the screen, then a center channel speaker isn't really necessary.

Both the yamaha htr5760 and the pioneer vsr1014tx-k receivers I am looking at are 7 channel, but I plan on only using a 5.1 set-up, b/c in a compromise to keep the wife happy, I have to keep the speakers as hidden as possible. As far as the rear surrounds go, I plan on keeping the ones I am currently using from my htib, since most sound comes from the fronts anyways. If a center channel isn't necessary, that's great! More money for a sub!

A better option is a center channel behind the screen and 2 front left and right speakers off to the side. This will make the sounds that pan from left to right, etc. more realistic. It will also enable you to use open baffle speakers which will give you more natural and clear dialogue and the sound is much more open instead of sounding like it is coming from inside a box. There are some nice 8" pioneer drivers that work well on OB for only $25 each, so $125 plus shipping for 5 and you'll have money left for a sub and subwoofer amp. http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=290-045. You'll just have some limited wood and supplies to buy. The only real drawback with open baffle is that getting bass is more difficult, but that's what your sub is for.

Will I need a tweeter since the high frequency roll-off of the pioneer drivers is 17 khz? Also, would I benefit from dual drivers for both the left and right since my room is rather large?

If you really want them only behind your screen, then just use 2 of the same driver, cut a hole in the sheetrock for each out near the left and right edges of your screen as low as makes sense since your screen is elevated. This will work well as what is called infinite baffle if there is a good bit more airspace behind the sheetrock and it doesn't get hot in there. It works well because the speaker cone is allowed to move freely without the pressures inside a box, but it won't have the open sound of OB.

Could this area benefit form some sort of dampening material? Could I build some sort of transmission line using this set-up?

For the subwoofer, from the pictures it looks like some of the walls have an attic on the other side of the wall. That's where the sub will go in an infinite baffle setup. Don't worry you won't even know that's where it is because sound waves below 100hz or so are omnidirectional and that's all the sub will play. You'll set the distance to you for each speaker in your receiver, so all the sounds get to your ears at the proper time.

Could I then put the sub above the plant-shelf behind the seating area to keep it completely out of view?

Now to make an open baffle believer out of you. Bill's still a non-believer. Take the drivers out of one of your existing speakers. If there's more than one set of wires make note of which goes where. Get a piece of cardboard. It doesn't have to be big, but the bigger the more bass you'll have. Cut holes with a seraded knife for the drivers and use duct tape around the edges to hold them in place on the cardboard. Reconnect the wires from inside the old box (you'll need some extra wire for this) Tape up any exposed bare wire so you don't blow your receiver. Then give it a listen along with your other speaker. It won't have the same amount of bass, but you'll hear that it sounds more open and natural than before and the other will sound like what it is....just sound coming out of a box.

I am going to try this as soon as I get a chance. What is the best material to use for the baffle in a permanent set-up? I am assuming it is something thin and sturdy. Thanks for all the help so far. I am going to put diagrams I drew up of where the speakers are actually going, in my next post, to help clarify everything.

 

[Bill Fitzpatrick]

JohninCR seems to have you convinced that open baffle is the end all and that enclosed speakers sound like they are coming from a box.

This is simply untrue as can be attested to by the hordes of happy box speaker owners.

Don't limit your options here just because he is all excited about open baffles.

I'm not a non-believer in open baffles but they are not always the best choice. Much depends on the situation.

 

[bluesboyjr]

Thanks, Bill, my mind is still open to whoever convinces me is the best for my situation. I do give much gratitude to JohninCR, though, for all the help he has given so far. By the way, have you been able to view the pics, b/c JohninCR has, so I'm pretty sure they are working?