New to DIY, seeking help with Khancenter

[losergamer04]

I just got done on another forum finding out how difficult it is to DIY from scratch. After a lot of talking I concluded building my own was still what I wanted but I'd need to use a tested design. Discussions and recommendations were made and I found DA Khancenter to be what I am looking for. I intend on building the In-Khan-netos as well as the fronts (vented) as well... eventually.

The forum mentioned starting another thread if I had questions, so that I am.

The XO shows only 1 speaker for the woofer. I am guessing that the two were combined in the XO design and should be run in parallel and proper polarity (unlike the front's woofers)?

There was mention of the speakers no longer being available and no need to change the XO. Is this still true? Also, I wasn't able to find pictures of the XO for the DA Khancenter. I'm going to try an mirror it to the best of my ability.

I have parts to return to PE and I will be using them to pay for the XO. This is going to be a slow process. Over the summer, if I'm not riding I'd like to be poking away at this. I'm hoping I can get this done before the fall semester starts, but I work full time, too, so I'll see how it goes.

You guys seem mighty helpful to everyone that as asked and I'd like to say thanks in advance.

[---k---]

Good luck with your build. Although I don't post as often, I do visit here about once a day and try and answer all questions about my speakers.

The RS180 woofers are run in parallel with REVERSED polarity to both woofers (Note the little red '-' sign). Take a close look at the crossover photo and you'll see the polarity is reversed.

Correct, the sheilded drivers are no longer available. But, CJD has done some testing and the new 8 ohm versions are close-enough. He's quite picky, so if he approves you're in good shape.

I've attached photos of the crossover. Sorry they weren't in the thread. I got bunches of photos, so let me know if you got any other questions. Make sure you read the whole thread, I'm sure there are a few hidden secrets in there.

[losergamer04]

Do you mind looking this over for me before I pull the trigger? It's about $30 more than when you did it 3 years ago.

Your Shopping Cart
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Dayton DNR-10 10 Ohm 10W Precision Audio Grade Resistor
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Dayton Audio DMPC-1.0 1.0uF 250V Polypropylene Capacitor
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Mills 2.5 Ohm 12W Non-Inductive Resistor
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Dayton Audio DMPC-50 50uF 250V Polypropylene Capacitor
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45 Day No Hassle Return Policy Order Subtotal: $163.50

[Silver1omo]

Currently PE has a stock of RS180S:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-364

[losergamer04]

Thanks for the heads up. I'm glad to see they have them back in stock.

It will be a few weeks before I order up the parts. The return needs to processed/refunded and I will be out of town at the end of May. *hits the pause button* Around the first of June I should be ordering the XO parts

Just for fun, if you had to (of even could) compare this to something one could buy, what would it be?

[---k---]

Ascend 340SE speakers. I owned a full Ascend 5.1 prior to these. Very similar voicing style.

Once upon a time, I ordered / borrowed a bunch of speakers and CJD and did some comparison to his RS150 MTM's. Included were: Paradigm Titan v2 (my original speakers), SVS SB-01 (because they were the "in" speaker at the time), Ascend 340SE (because they were also a cool speaker at the time), DynAudio 42, and Paradigm Studio 40. I thought the DIY RS150 MTM was the best. The Ascends were second, and depending on type of music and volume level, they at times were very similar. The SVS were good for a cheap small speaker, but the bass was, I'll never forget CJD saying this, "like banging on a rubbermaid tub." So true. The Dyn's were an odd speaker. I really liked the sound, but it was not true to the source. The Paradigms were, well, Paradigms.

[losergamer04]

Complete noob question here, but what kind of effect would adding a curve of some sort to the enclosure have? I've read it helps diffraction issues that square boxes can create.

[---k---]

Adding curves to the sides or back is good. Having non-parallel sides may prevent sound from bouncing back and forth, so it can help. It's not within my wood working skill set, so I've never attempted it.

[losergamer04]

What if I used a trapozoidal design? Up the front by an inch or two each way and reduce the back by the same? Do you think that would have the same effect, so long as I kept the volume the same? I could use a dowel and spike to prop up the back.

[cjd]

The realistic gains from doing this are probably not worth the effort for a center, especially if you ever think you might want to set the TV right on top of it

It probably can deal with adjusting the height of the baffle more than most designs since it's designed (crossover-wise) to sit right under a big glass surface with as few issues as I could manage.

[---k---]

Are you trying to make it shallower? or Sexy?

If shallower, make sure you read towards the end of the thread. I way oversized my box. I'm pretty sure that I did some modeling that showed that you could reduce the depth quite a bit. I don't remember off hand but from like 20" down to 16" or maybe 14" isn't a big deal - especially if you're using the new woofers, which I believe like slightly smaller boxes.

Of course, you're always encouraged to take the hobby to the next step and model the woofers up yourself. It really isn't that hard. I taught myself Unibox. Give it a go. :T

[losergamer04]

I was more talking sound quality. But it seems the effort in the enclosure will not be worth the gains. I guess I will stick to the plans. It will be a few weeks before I can order the XO parts. It seems attending weddings is more expensive than I thought >_>

[---k---]

Ahhh... people like to get fancy with their boxes. I'm not one of them because I'm lazy, so my opinion is biased in that direction. But, my results have been pleasing enough that I'm not rushing to re-evaluate my bias.

[BeerParty]

I was more talking sound quality. But it seems the effort in the enclosure will not be worth the gains. I guess I will stick to the plans.

The stuffing inside the box is there in part to address the concerns about internal reflections. Diffraction effects are addressed by the baffle width and edge (most baffles have a round over for this reason).

Non-square cabinets built around here are almost exclusively built for their aesthetic qualities. If you have the woodworking skills and the time, we would love to see the pictures of your curved cabinet build. So if you want a lot of people to follow your build thread, build curved cabinets! :P

[BeerParty]

It seems attending weddings is more expensive than I thought

Been there. Learned that. Bought the tee shirt. :twisted:

[losergamer04]

I haven't forgot, I swear. Sadly, a ferret had to be taken to the vet last week for an emergency visit. She's fine but the XO's will have to wait yet another week.

[---k---]

No worries. You're still likely to beat ET to complete some of the projects he says that he is working on.

[losergamer04]

Well, I'm waiting on a job that may move me or a house I may buy... But the box will be built in a few weeks (I hope).

[---k---]

Well, we'll be looking for an update.

[losergamer04]

The guy is going to start working on the box as soon as I get him the MDF and glue. I have a question about the foam or, rather, Acusta Stuff. Would a bag of Acousta Stuff be a good alternative? I ask because I'm trying to make it as easy on him as I can and I could just stuff the Acousta Stuff (pun intended) in there after it's put together.

And I remember there being a website that had these posted with plans. Can you link it? I can't find it again and I seem to have lost the book mark. Sorry, I can be a little (read, a lot) scatter brained some times.

Crap, and how many sheets of MDF does this need? Don't worry, I plan on having more sleep in me before I start the XO.

[---k---]

Everything is a tradeoff. I can't say how much. What I used on mine is sort of middle of the road. JonMarsh uses much fancier foam, others use Foambymail.com.

Stuffing with AcustaStuff will have many of the same effects, but not all. I would suggest stuffing with R13 Fiberglass insulation cut to size and thickness instead of Acustic Stuff, but only from a cost perspective.

Most important to get foam directly behind the driver. You can probably reach most of the surfaces but cutting small squares and placing it through the driver cutout afterwards. The amount of stuffing and foam does affect how the speaker will sound, so if you don't build it exactly the same way I do, you might or might not need to experiment with adding more or less stuffing to get it to sound the same as mine.

A better alternative might be to ask him to build it with a removable from baffle. Have him put some cleats on the inside that have threaded inserts. Then use some thin weatherstripping or speaker gasket between the box and the baffle. It shouldn't be that much more work for him and will be less than dealing with the foam. Then you can add the foam yourself easily. Zaph builds all his boxes with removable front baffles.

First post in mission accomplished has the best plans:

http://www.htguide.com/forum/showthread.php4?t=28262

If you're having someone else build your box for you: Make sure you give him the drivers so he can measure them and TELL HIM TO DOUBLE CHECK ALL MY DIMENSION!!! Warn him the the tweeter and the mid are EXTREMELY tight and likely end up touching - or if your cut is a little off, you have to shave your RS28 flange down a little like I did. It is close by design, but it doesn't have to be that close. Of course it is close on the top too. Also, make sure he understands the drivers are supposed to be recessed. Probably best to print out some of my build photos and show him. Same with chamfering the back side of the drivers - especially the RS150. This is important and doesn't show up on the drawings. Oh, and the roundover on the front baffle doesn't show up either... but isn't necessary since it was designed to be installed flush, but I think looks better.

If you want to make it easier on your guy, you can eliminate the one brace too.

Here is a great program to let you layout the cut and figure out how much MDF you need:

http://delphiforfun.org/programs/cutlist.htm

[losergamer04]

You said R13 cut to thickness, how thick is it?

I'm a little paranoid about the order so can you confirm the drivers before I hit the GO button? I linked my cart for XO parts above earlier. $331.79 in total

Dayton Audio RS150-8 6" Reference Woofer X 1
Part Number: 295-354

Dayton Audio RS28A-4 1-1/8" Aluminum Dome Tweeter X 1
Part Number: 275-1

Dayton RS180S-8 7" Reference Shielded Woofer 8 Ohm X 2
Part Number: 295-364

[---k---]

Yes. Those are the correct drivers.

If you want to save $16 you can buy the RS180-8 (non-shielded) part number 295-355. CJD has said that they are nearly a drop in replacement.

R13 thickness, well here is where it gets to be a little black art. I would say a layer about 2" thick would be good. Use spray glue to adhere it. Then stuff with loose fistfulls of R13 as needed. I did my subwoofer and my brothers Sietecerocero this way. It works. A gooden ear like CJD would probably spend a lot of time tuning the stuffing, but I don't. I just spend sleepless nights wondering if I should add more or less.

This is from the Sietecerocero thread. Could be thicker on the back. You just don't want to over do it around the driver.

[losergamer04]

Bad news, my '97 Dakota is holding fluids like a seive. It's been needing fluids (power steering, oil, coolant) slowly but today a leak came. It's going to need some work. This means funds are being redirected Maybe in 6 months after I get me a nice Jeep with a 4.0L in it. I think I am going to have the box built but it's going to be a while before I can wire up an XO.

[---k---]

The Khancenter is great. But, I was very impressed with what ~$85/per speaker got me when I built my brothers Sietecerocero. Something to consider.

[looneybomber]

Weigh your priorities, $350'ish vs. $85. I say, sell the truck, walk to work, and build an entire Khanspire 5ch setup.

On a serious note, I was one of those talking to you on AVS that led you to HTguide, but I don't remember what your current setup is. If you have some L/R's, use them alone for another 3-6 months. It's better than nothing.

[losergamer04]

Yeah, I've got some Polks and that's all I have hooked up. They are not so great. I've been dying to build up a good set. I think these 8 year old, $200 for the pair speakers are not doing my Adcom 7607 with a Dennon 2808-CI (pre only) justice...