CraigG's KhanCinema Build Thread

[Hdale85]

So the extra output of the Silky RS takes care of what the screen takes away?

[CraigG]

Dougie, build a trio of Khanspires, use the silk dome version of the RS tweeter.

I've been on the fence about substituting the silk-dome tweeters in my front channels ever since I came across the discussion about them in the KhanSpire thread. You've just pushed me off. I ordered three silk-dome RS28s, and printed the return form for three of my aluminum-dome versions.

BTW, I got a sample of the Seymour screen material, and it's quite a bit better visually than the material in the Elite screen I've got. (Should be the roughly the same acoustically.) Looks like a DIY screen is in my future, too...

[cjd]

The Seymour screen should be better acoustically.

Roll off is fairly smooth except on the very top end, where I think it's about impossible to be super smooth going through any type of fabric (includes grilles). The silk dome won't be perfect, but it will help a little.

[CraigG]

OK, so I got some PE Sonic Barrier foam, and I was working on laying out dimensions of the pieces for the mid chambers. I figured I might need to make the sides a little shorter on the KhanCenters to clear the sides of the mid magnet, so I did some test-fitting to check.

Well, let's say I attempted some test fitting. Turns out the mid chamber from the original KhanCenter sketch is 4 1/4" wide, but the magnet on a RS150S-8 is 4 1/2" wide.

So, before I go nuts with the file/rasp/router/laser/explosives, is it going to cause a problem for the mid to be pinned in there on three sides? Should it have more room to breathe?

Also, what's the volume supposed to be for the mid chamber? When I calculate based on the original sketches, the mid in the KhanCenter only has about half the volume of what the same driver has in the In-Khans. Clearly, I've gone wrong somewhere, but where?

[---k---]

Well, let's say I attempted some test fitting. Turns out the mid chamber from the original KhanCenter sketch is 4 1/4" wide, but the magnet on a RS150S-8 is 4 1/2" wide.

They must have revised the driver and made it bigger. ops:


I'm really sorry about that. I didn't take good measurements during this build, and the documentation probably shows. In fact, the sketchup was even made by someone else. I'll try and put a note under the model.

So, before I go nuts with the file/rasp/router/laser/explosives, is it going to cause a problem for the mid to be pinned in there on three sides? Should it have more room to breathe?

Also, what's the volume supposed to be for the mid chamber? When I calculate based on the original sketches, the mid in the KhanCenter only has about half the volume of what the same driver has in the In-Khans. Clearly, I've gone wrong somewhere, but where?

The volume of the mid chamber really isn't super critical, unlike a woofer, because of the crossover point is above where they start to drop off. If you read the original Khanspire thread there is a little bit of talk about it. CJD was proposing 15L - 16L for a pair, or about 7 - 8L each. CJD is a big believer in allowing the drivers lots of room to breath, so this is more than others would probably say is 'required'. For some reason, I dropped down to about 5L for the Khancenter (probably because I didn't do enough planning ahead of time with this one, but luckily a talent like CJD's can make anything sound great!). I think I was actually a lot wider than the 4.25" shown...maybe like 5.5". (5.5"*6"*9.375" = 5.0L) Really sorry!

Can you post pictures that make show how tight it is? Maybe we can come up with some ways to fix it without getting to crazy.

[Hdale85]

Jed likes the oversized mid chambers as well, They've always sounded great in the designs of his that I've built.

[CraigG]

They must have revised the driver and made it bigger. ops:


I'm really sorry about that. I didn't take good measurements during this build, and the documentation probably shows. In fact, the sketchup was even made by someone else. I'll try and put a note under the model.

No worries! I'm REALLY glad I didn't glue up the rest of the enclosure before finding this.

Can you post pictures that make show how tight it is? Maybe we can come up with some ways to fix it without getting to crazy.

It wouldn't be too much trouble to take 1/8" out on each side to allow the magnet to at least fit in there, but there's not much breathing room except at the top.

I suppose I could cut most of the existing mid-chamber sides away, and add another piece on the outsides:



The only drawback is that it would take a little volume away from the woofers...

[Hdale85]

I would do option 2(sketchup drawing), that little bit of volume wouldn't make much of a difference at all.

[---k---]

OUCH! Yeah, that is a typo. I put a big red warning in the original thread to hopefully prevent other people from making that mistake... I'm really sorry about that.

You're not far enough along with that piece, that the mod you show in your sketch-up is a no brainer or just redo it completely. I wouldn't mess with a rasp; it is likely more work and the rs150 likes to breath.

[---k---]

Just make sure that your modification doesn't put you in the same position with the RS180s.

[CraigG]

OK, by adjusting the height of the chunk I cut out of the mid chamber sides , I can get 5L for the mid.

I calculated the woofer volume from the original sketch to be 48.7L, but with the mid chamber width corrected to 5 1/2", it looks like it really should be 47.4L.

The woofer volume for my version was going to be 48.8L, and adding the extra side plates to the mid chamber drops that to 46.8L. My version also doesn't lose any volume to crossovers, so I think I'll still end up really close to the actual volume of the original.

Ryan, as long as you're making corrections, what's the baffle width supposed to be on the In-Khans? That thread mentions both 9" and 9 1/2", and the sketches show 9 1/2". When I calculated the woofer volume, it was closer to the 18L target using 9" for the width, so that's what I used. EDIT: Looks like I made a mistake there, too--I forgot to account for the bottom thickness when I calculated. I get 17.4L @ 9" width, or 18.6L @ 9 1/2" width.

[CraigG]

Just make sure that your modification doesn't put you in the same position with the RS180s.

Yeah, I checked that--should be no problem there.

[---k---]

Ryan, as long as you're making corrections, what's the baffle width supposed to be on the In-Khans? That thread mentions both 9" and 9 1/2", and the sketches show 9 1/2". When I calculated the woofer volume, it was closer to the 18L target using 9" for the width, so that's what I used.

Well... that is another funny one. ops: I just got out the tape measure and measured it. It was 8.875" I then remembered that I was shooting for 9", had my fence set wrong and ended up with 8 7/8".

The great thing about building sealed speakers is that the volume doesn't have to be exactly anything. Small variations in size isn't going to make much of a difference and you can do a lot with polyfill to adjust the tuning to suite. Nothing to get too worried about and gives a lot of room to put the 'I' in DIY.

[Hdale85]

WoW 9, 9.5, finished speaker 8.875 :B Oh well junk happens.

[CraigG]

OUCH! Yeah, that is a typo. I put a big red warning in the original thread to hopefully prevent other people from making that mistake... I'm really sorry about that.

Here's a revised sketch of the original for your main KhanCenter thread:

[CraigG]

WoW 9, 9.5, finished speaker 8.875 :B Oh well junk happens.

Yeah, my In-Khans mysteriously lost 1/8" of depth from what I had planned...

[CraigG]

In-Khans are DONE!





Good tip on that Sherwin-Williams All-Surface stuff--I really like how it turned out. If these weren't going to be buried in the walls, I would add a second coat--the difference between MDF faces and edges is slightly visible, because the edges sucked up more of the paint.

So how do they sound, you ask? All I've got at this point is a quick first impression. I put a pair of them in place of my front left and right speakers, and despite having them poorly positioned, not running through the Audyssey setup to re-EQ them vs. the settings for the current Klipsch speakers, having made NO effort to integrate them with the existing center channel, and only having about 20 minutes to try them out, I can say that they sound friggin fantastic! There's certainly more bass available than with the Klipsch, and it's beautiful, lovely, tight, controlled bass. There's a stunning, and I mean really obvious, improvement in midrange clarity. On the high end, the improvements aren't as immediately obvious (although I certainly haven't LOST anything here)--I would have to take more time to set up properly and more listening time to make a fair assessment. So far, though, these seem to be everything I had hoped for!

I'm REALLY excited to get the fronts finished, get everything in place and set up properly, and start enjoying them!

[Hdale85]

Wow that's a pretty interesting cabinet.... So does the bottom driver have more cabinet space then the top?

[CraigG]

Wow that's a pretty interesting cabinet.... So does the bottom driver have more cabinet space then the top?

Yes, the volumes for the mid and the woofer are the same as Ryan's original In-Khan-Neatos. I just shuffled things around a bit to close off the tweeter and crossover into a separate section.

[---k---]

It looks like you recessed your tweeters exactly like I did - TOO DEEP!

Zaph uses some of that ~1/8" thick pink foam that you get in packaging sometime or that you can buy at a craft store to fill in the gap behind the tweeter. I've built up the thickness using a couple of layers of paint, and more recently duct tape. Not being able to do an A/B comparison, I'm not sure how subtle the improvement is, but it will show up in measurements... AND, besides it will impress your wife and friends even more if that tweeter is perfectly flush!

Really though, the look great. I'm glad the paint worked out for you. I'm really glad (relieved) that you're digging the sound.

[CraigG]

It looks like you recessed your tweeters exactly like I did - TOO DEEP!

I figured as much. Well, if I'm going to be pulling one driver, I might as well pull all three, and add that second coat of paint!

I'm really glad (relieved) that you're digging the sound.

Me too! After ordering all the parts, I started to worry that there might be some aspect of the Klipsch speakers that I would miss related to the horn, the ported woofer, etc. I fully expected the In-Khans (and KhanCenters) to be better speakers overall, but I didn't know if the Klipsch would still have any points in their favor, and if those would turn out to be important. Well, they don't. The Klipsch are fine speakers and never gave me reason to complain, but the In-Khans are in an entirely different league.

My only reservation now is that I almost think I went too far. It seems almost embarrassingly decadent to use these as surrounds--like buying a Ferrari just to drive to the mailbox. That's the point of overkill, though, right? That's why I jumped over some of the more budget-friendly, get-your-feet-wet type of projects, and went straight for the big guns--to be sure they would do everything I could ever ask of them.

And that leads to my other "problem"--I've really enjoyed building these, but now I'm left with no reason to build any others. I guess I could look for a decent, inexpensive amp--then I could start churning out powered computer/iPod speakers for friends & family...hmmm...

[Hdale85]

Well in the DIY world the designs available at certain price points just aren't comparable to the commercial offerings of the same. You say they are a ferrari, but in this world it's more like a VW/Audi Which isn't bad at all, (after all I own a VW). But it shows you how much money speaker companies make and how far they are willing to go to make more. Although I think Klipsch makes some great speakers for the money for non DIY. I found my old RF-62's to be similar to what I heard with the NatP's in tower form. Although the NatP's did play lower for sure.

[Solid7]

Well in the DIY world the designs available at certain price points just aren't comparable to the commercial offerings of the same. You say they are a ferrari, but in this world it's more like a VW/Audi

I would agree with you if we were talking about a Phaeton or an RS-4.... :B

[Hdale85]

You have to leave some room, because there are insane designs like the Accuton based designs and what not. These would obviously be the Ferrari's and what not of the world. Then there are the higher end 3 way designs.....granted I can't judge this area as I own one of them and I'm not sure how the Khans compare. But the In-khan-neato's are surrounds and obviously the Khanspires are going to outperform them. So I think a midgrade audi/vw is about accurate lol

Edit: not that they have to be used as surrounds, would work well as an LCR as well.

[CraigG]

I didn't mean to imply that these are the Ferraris of the speaker world, just that their capabilities are grossly underutilized as surrounds. I might have to try out some DVD-A or SACD material, just to give them something to do!

As far as car analogies go, I'd say these are firmly in Mercedes territory, for Camry money. :T The Spasvogels, and some of the Accuton designs, etc., would be more like Bentley territory for Mercedes money, and those beautiful Galacticas mentioned here recently would be something like Veyrons for (merely) Ferrari money. Of course, having heard none of the others, I could be way off--we might be talking about something that looks like a Bentley, but performs like a Yugo.

[Hdale85]

Oh with the Talent involved I don't doubt the quality lol.

[---k---]

I would describe them as an Acura.

[Hdale85]

Acura fits.

[CraigG]

Mid chamber problem in the KhanCenters fixed:

[Hdale85]

Looks like a good fix!

[---k---]

Cool. I'm glad you found an easy solution.

[CraigG]

More Progress...

KhanCenters ready to attach baffles:



The baffles (and backs) ended up being a bit short of the height of the center section. I had been fixing errors like this on the tops and sides with the sander, curving them just a bit so that everything came out flush. This has been working fine, and the amount of material removed has been small enough that they don't even look curved.

Well, on the bottoms, I should have known this wouldn't work, because the error was significantly larger, and the bottoms need to be flat so the speakers don't rock. For some reason, I tried anyway, and ended up with a mess:



Not good. Fortunately, I had seen a woodworking article a couple of months ago outlining a process for making an old workbench flat using a router. I adapted this process by making up a sort of sliding table apparatus for the router using a scrap of MDF, a couple of aluminum straightedges, and some clamps:



This allowed me to remove the remaining material necessary to make the bottoms flat again. As you can see, I had to take A LOT off to get back to flat, like up to 3/8". This left the bottoms pretty thin, so I laminated on another 3/4" sheet onto the bottom of each speaker. This time, I did what I should have been doing all along--I cut the panel oversized on all four sides, and used a flush trim bit to remove the excess after it was attached.

To correct the not-quite-flush tweeters in the surrounds, I found some black foam board at Target. I located some appropriately-sized cans in the pantry, and used an Xacto knife to trace around them to make some spacer rings:



They're thicker than what I need, but they can be compressed down quite a bit, so I should be able to just tighten the mounting screws until the tweeters are flush.

[CraigG]

Done!



My wife suggested that it would be nice to have these ready in time to watch Iron Man 2 (released on Blu-Ray today), so I busted ass the last couple of days to get it done. I got the fronts painted and covered in felt, drivers & crossovers installed, rebuilt the wall under the sub, got all 7 speakers installed, and re-ran the receiver's Audyssey calibration.

The verdict: THESE THINGS ARE AMAZING! I really couldn't be happier.

Thanks to everyone for your support & advice, and especially ---k--- and cjd for these fantastic speaker designs!

[---k---]

Awesome! I'm glad you're liking them. That looks like a pretty sweet setup. I would love to see a photo from even further back.

I am a believer in a little driver break-in. Don't do anything funky with them, but give them a few hours of good usage before you go critical listening or playing with the stuffing. Iron Man should just about do it! . Let me know how Iron Man2 is, I got to wait Netflix's 30 days.

[cbark]

Now that is a wall of sound! 8O

Love that the wife had her input also. Get it done....or it would be nice... :P

[cjd]

That looks like a fun setup!

[Hdale85]

Looks great!

[CraigG]

Awesome! I'm glad you're liking them. That looks like a pretty sweet setup. I would love to see a photo from even further back.

Getting further back is tough--it's a funky-shaped room built over the garage with a ~2-foot high by 3-foot deep "shelf" along what's now the back wall. Where I was standing for the pic was up against the shelf. I'll see what I can do after I get the rest of the wall covered in black felt.

I am a believer in a little driver break-in. Don't do anything funky with them, but give them a few hours of good usage before you go critical listening or playing with the stuffing. Iron Man should just about do it! . Let me know how Iron Man2 is, I got to wait Netflix's 30 days.

I was wondering about break-in. Right after getting them installed, I noticed an intermittent "scratchyness" in one of the speakers, but it was acting like it only resonated at certain frequencies. At first I suspected maybe one of the clips in the screen frame was rattling, but it was still there without the screen.

My next thought was that I messed up the crossover or wiring, but everything checked out OK. After I had removed and reinstalled the tweeter, the problem seemed to have disappeared, and we watched Iron Man 2 without noticing any issues (loved it, BTW!).

The next day, I tried out some music, and the resonance/scratchyness came back. The synth/thunder at the beginning of "Brothers in Arms" REALLY brings it out--it sounds awful. The good news is that when I swapped the tweeters in the left and right speakers, the problem followed the tweeter, so I haven't screwed anything up. The bad news is that I've got a defective tweeter.

It's not present (or maybe just not noticeable) at low volume levels, so I've left the speakers in place, and for watching TV, etc., it seems to be OK. I ordered a replacement from PE, and I'll return the old one as soon as it gets here.

[evilskillit]

Getting further back is tough--it's a funky-shaped room built over the garage with a ~2-foot high by 3-foot deep "shelf" along what's now the back wall. Where I was standing for the pic was up against the shelf. I'll see what I can do after I get the rest of the wall covered in black felt.



I was wondering about break-in. Right after getting them installed, I noticed an intermittent "scratchyness" in one of the speakers, but it was acting like it only resonated at certain frequencies. At first I suspected maybe one of the clips in the screen frame was rattling, but it was still there without the screen.

My next thought was that I messed up the crossover or wiring, but everything checked out OK. After I had removed and reinstalled the tweeter, the problem seemed to have disappeared, and we watched Iron Man 2 without noticing any issues (loved it, BTW!).

The next day, I tried out some music, and the resonance/scratchyness came back. The synth/thunder at the beginning of "Brothers in Arms" REALLY brings it out--it sounds awful. The good news is that when I swapped the tweeters in the left and right speakers, the problem followed the tweeter, so I haven't screwed anything up. The bad news is that I've got a defective tweeter.

It's not present (or maybe just not noticeable) at low volume levels, so I've left the speakers in place, and for watching TV, etc., it seems to be OK. I ordered a replacement from PE, and I'll return the old one as soon as it gets here.

I had something really similar with an RS125 once. I thought my tweeter was toast because at certain frequencies it would squeal, very shrill, but only a bit and occasionally. Then one day I was playing some violin music and it kept doing it so I figured to heck with it, I'm going to figure this out and if it breaks it then I'll get a warranty replacement. So I played with sine waves till I found the frequency, turned out it was about 650hz, it was in the woofer. So I played that tone and kept turning it up and after a few seconds it stopped, and never did it again. I'm guessing a piece of grit was either in the gap, or between the cone and the phase plug. Either way it went away and never came back. Don't know if that helps at all, but the one time this sort of thing happened to me, thats how it played out.

[---k---]

I don't want to start a witch hunt, but I had to return one of my RS28A. It sounded a lot like what you described. I ran a impedance sweep with a woofer tester 3 and the impedance was funky. PE gave me no issues swapping it out.

If it moves with the tweeter and its only from one speaker, it sounds like the tweeter is bad. There are a few here who would just disassemble it and recenter the diaphragm. But, I would send it back.

I've also had a little scratching sound from one of my RS180. But, that was my fault from some dust or something that got in the gap between the phase plug and the cone. Could see it. Blew that out and it was better. I really shouldn't take the woofer out into the garage for test fits with saw dust all over the place.

[CraigG]

The replacement tweeter is in, and all is right with the world. As usual, Parts Express customer service was great to deal with--no issues at all with the return. They offered to send either a replacement diaphragm or a complete speaker, but when I informed them I had already purchased a replacement, they were fine with crediting the price back to my card, and immediately emailed me a prepaid Fedex label to return the bad unit.

Now I've got to get all my old Klipsch speakers sold, which means I need to get set up to demo them in the garage once I get them posted on Craigslist. I don't have a spare receiver to drive them, so I was looking for something either a) cheap enough to be disposable, b) a good enough value that I'd have no trouble reselling it for what I paid, or c) good enough quality to keep and re-use elsewhere. I came pretty close to hitting all three options--I scored a pristine Rotel RA-931 integrated amp for $55. Not a lot of power, but sounds wonderful with the efficient Klipsch speakers, and will do a fine job of powering a future set of DIY computer speakers for my wife.

After being a little stunned at just how good the Rotel sounded with a cheap DVD player as a source and a pair of Klipsch floorstanders, I thought just for grins I'd hook it up to the L and R Khancenters. Again, it sounded very nice even with the receiver out of the picture, which got me thinking about just how much value the Denon receiver's Audyssey eq/room correction was providing.

I did some comparisons and looked at the Audyssey EQ settings the receiver was coming up with, and it turns out it's really not doing very much at all. I had a very hard time distinguishing between corrected and "straight through" sound, and an even harder time deciding which was better. This was definitely not the case when I was using the Klipsch speakers--the difference was immediately noticeable, and the corrected version was clearly superior. What this tells me is that my room's acoustics aren't all that bad, and most of what Audyssey had been correcting was the issues with using my bookshelf speakers in-wall, and possibly shortcomings of the speakers themselves. Both of those issues are gone now, leaving Audyssey with very little to do.

Comparing the new speaker to the old ones in a corrected-vs-corrected system, I'm very satisfied with the improvements. But in an uncorrected-vs-uncorrected comparison (which I haven't done, directly), the gap would widen, and the new speakers would really just blow the old ones out of the water. Once again, kudos to cjd and ---k---! ;x(

This discovery also opens up possibilities for a future receiver upgrade. I'm pretty happy with my Denon, so I don't have a pressing need to upgrade here, but more HDMI inputs would be nice, as would the ability to decode DTS-HD MA and TruHD directly. Audyssey MultEQ made such a big difference in my old setup that I wouldn't have considered another receiver without it. Now it appears it's not really necessary, so I have a lot more options. Also, being an addict to overkill and a sucker for a sale, I just picked up another Emotiva amp (UPA-5 for $399 shipped :T ) to power the surrounds. I already have an XPA-3 driving the fronts, so now I'll have outboard power for all channels, and I can consider not just receivers but dedicated pre/pro's, too. Hmmm...

[---k---]

:T

I love hard data like that. The Audyssey has to do nothing! That is fantastic, especially since you're sticking them in the wall and all.

Good luck getting the old stuff sold. Depending on your market, Craiglist can make it pretty easy.

[FracturedDS]

How would you compare the In-Khan-Neatos vs the Khancenters as mains? I was originally planning on doing the SL/L/R/SR with the In-Khan-Neatos and the C as Khancenters. Do you feel going with the Khancenters as L/C/R would be a worthwhile upgrade?

[---k---]

You might gain a little more capability. But, there is something special about the In-Khan. The design turned out really nice. I'm very happy with the Khan-center too. I would decide based upon what placement works best for you.

[FracturedDS]

I will Stick with the In-Khans for the L/R, I love the design and I can't wait to get these up an running. Do you have a suggest amp power to run these?