Let's say that I was planning on performing the same build, but was not scared of large center channels. Would you change anything on the XO to build it as a WW-T/M-WW 3 way with all the DA175s in a horizontal row and the RS28F above the Center? I'm assuming that there may be a need for less baffle step correction.
The surrounding environment would indeed affect baffle diffraction. In all likelihood, you'd want to relax the woofer inductor slightly if this was directly under a screen, but then the DA175 mid might not be able to keep up. As it is now, there's no padding at all on the mid.
But if your receiver has auto correction (Audyssey), then it wouldn't make much difference either way, as it would EQ back to flat for you.
R = h/(2*pi*m*c) and don't you forget it! || Periodic Table as redrawn by Marshall Freerks and Ignatius Schumacher || King Crimson Radio
If you simply blocked off the section behind the woofer under the tweeter in your illustration above, and extended it to the brace, that would be plenty. Just fill in the void in the brace in that section and you'd have more than enough. Leave the area behind the brace open, allowing all the woofers to share a single common volume.
For a sealed mid chamber, you could probably get away with as little as .3 cubic feet, and maybe even less than that.
Yup, that'll work. Mid just needs to be close to the tweeter (above or below, depending on listening position and preference), as pointed out before.
Volume and size of the enclosue looks good? I have it WWTMWW. I just want to be sure before I start this project. I would hate to get alot of money in it and not be happy.
One more point . . . the way you have the woofers distributed on the baffle, you could simply run the chamber all the way to the back wall if you wanted, separating the top two woofers from the bottom two. Looks like you have almost identical chamber sizes above and below the mid chamber.
R = h/(2*pi*m*c) and don't you forget it! || Periodic Table as redrawn by Marshall Freerks and Ignatius Schumacher || King Crimson Radio
One more point . . . the way you have the woofers distributed on the baffle, you could simply run the chamber all the way to the back wall if you wanted, separating the top two woofers from the bottom two. Looks like you have almost identical chamber sizes above and below the mid chamber.
The one piece brace with holes was conceived when the Schumakubin was a commercial design effort. It is not necessary to exactly duplicate that brace. here is how I did mine, no mid enclosure.
The one thing the deeper chamber gives you is the ability to get more sound deadening material between the woofer and the rear wall that will reflect the rear wave back toward the cone. Could lead to cleaner mids, though the shallower chamber is probably still adequate for the task.
R = h/(2*pi*m*c) and don't you forget it! || Periodic Table as redrawn by Marshall Freerks and Ignatius Schumacher || King Crimson Radio
The one piece brace with holes was conceived when the Schumakubin was a commercial design effort. It is not necessary to exactly duplicate that brace. here is how I did mine, no mid enclosure.
Thanks for the example, I wasn’t sure how much the design on the center brace played on how the speaker sounded. The only thing I did to the original design is to add .5 cubic feet volume for the additional speaker. I am hesitant to change it too much because I know Pete put things in certain places for a reason.
Originally Posted by Pete Schumacher ®
The one thing the deeper chamber gives you is the ability to get more sound deadening material between the woofer and the rear wall that will reflect the rear wave back toward the cone. Could lead to cleaner mids, though the shallower chamber is probably still adequate for the task.
I will model it up with a deeper chamber as you suggested and post it when I get time to mess with it. Thanks Pete!
Some builders make elaborate bracing from sheet mdf or ply, much machining and hole cutting. I tend to put my bracing together from sticks. Much easier IMO. The point of bracing is to prevent the sides of the enclosure from flexing from the sound waves. You need more bracing than most new builders would imagine.
Looks good to me. What's the overall volume in each woofer chamber? Should be somewhere close to 1 cubic foot if you're going sealed.
Ok in the top WWT chamber it is 1.102 cu ft.
The M chamber is .36 cu ft.
Then the lower WW is 1.266 cu ft.
I’m not taking into consideration the woofers themselves protruding into the chambers along with the tweeter.
Ok in the top WWT chamber it is 1.102 cu ft.
The M chamber is .36 cu ft.
Then the lower WW is 1.266 cu ft.
I’m not taking into consideration the woofers themselves protruding into the chambers along with the tweeter.
Looking good. The volume taken up by the woofer/tweeter structure protruding into the cabinet is fairly small for those drivers, so I wouldn't be concerned with the .1 or .2ft3 they'd take up. You can account for it, though. Perfectly acceptable to factor that volume into your cabinet build. Nice drawing!
John A.
Four wheels move your body, two wheels move your soul.
"Children play with b-a-l-l-s and sticks, men race, and real men race motorcycles" - John Surtees
Emotiva UPA-2 amp, USP-1 pre-amp, ERC-1 CD player
Yamaha KX-390 HX-Pro cassette deck
Pioneer TX-9500 II tuner
Yamaha YP-211 TT w/Grado GF3E+
Statement Monitors
Thanks!
I did end up picking up my DA175-8 woofers at 20% off at the tent sale this past weekend. I wanted the RS28F-4 tweeters, but found the RS28A-4 tweeters for $28 a piece so I went that direction.
The one piece brace with holes was conceived when the Schumakubin was a commercial design effort. It is not necessary to exactly duplicate that brace. here is how I did mine, no mid enclosure.
Re: Vince's VHT
Originally Posted by Pete Schumacher ®
![$vboptions[bbtitle]](images/techTalkHeader-leftGray2.jpg)
![$vboptions[bbtitle]](images/techTalkHeaderRepeatGray3.jpg)
Reply With Quote
