MarkK's Rs22528A as surrounds build thread

[joeybutts]

Cab construction is complete! Need to round over the two vertical edges and flush the baffle edges, but other than that, good to go.

Things are beasts for TM's. Weighed them tonight. 29 lbs unloaded.





Mag for size comparison





Next to the D8's









Pop can size comparison









Me for size comparison....Fiance thinks I'm crazy.

[joeybutts]

Cabinets have one coat of 65/35 glue/water on them. Going to give them a nice scuff of 220 and give them a coat of resin, and prep them for priming!

Fully sanded.





Baffles routed and sanded









First coat of "sealer"

[joeybutts]

So got a chance to listen to these without the proper crossover network in place but using some active processing, and ....well......

LOVED THEM. OMG. I know that it was only a rough idea of what they will sound like when completed (due to the crossover not being in and only running on a combined maybe 30W and some leaks through the binding post holes where i ghetto-rigged it.....) but the extension and smooth tone and airiness was so sweet. I have some pics of the drivers installed and will post up later today.

[capww8]

What is the volume of the cabs? They look a bit bigger than .75 ft3

[joeybutts]

What is the volume of the cabs? They look a bit bigger than .75 ft3

I think they are a bit bigger.....like .76 cubes. :W

Seriously I think they come out a shade over .75 after displacement and what not.

[capww8]

Thanks. I'm building these also, and my .75 cabinet looked really small compared with yours... must be a slightly different shape / angle combined with my craziness.

I'm really glad to hear your initial report of good sound from the box... I'm still weeks away from turning mine on... I've got all the parts, but it's 110 degrees here. Way too hot to finish the cabs.

[kgveteran]

Here are my modified i built about four years ago. They are killer rear and back surrounds. I think they are 8" deep. That kinda ruined the bottom end, but i Crossover @ 80hz...no big.....they begin to rolloff around 50hz.

Sorry to hijack

[joeybutts]

Off the top of my head I think the dimensions on mine are 17h x 10w x 14d with 1" walls. And yes, it has been tough keeping the dripping sweat off the cab's, but now that they are coated in resin, don't have much too worry about. Hoping one more coat does them good.

Thanks kg and no worries on the hijack. As long as it is relevant I don't care. I remember checking out your pics before...maybe a thread? When I was listening to them roughly active, they seemed to dig pretty low, and wow did they seem to have nice off axis response....

[joeybutts]

Pics

[Bear]

I'm curious: why did you stop the roundover short of the ends? On the woofer side, you probably won't get too much diffraction, but on the top near the tweeter, the pointed corners will almost surely be measurable (potentially audible to a non-trained ear). This is less relevant for surrounds, but if you go to multi-channel music, it may bug you later on down the road...

[joeybutts]

I'm curious: why did you stop the roundover short of the ends? On the woofer side, you probably won't get too much diffraction, but on the top near the tweeter, the pointed corners will almost surely be measurable (potentially audible to a non-trained ear). This is less relevant for surrounds, but if you go to multi-channel music, it may bug you later on down the road...

Purely aesthetics. I thought that the roundover passed high enough from the tweeter that it wouldn't have too much impact on the sound.

Has there been any testing on at what distance does a variation not exist at the edge of the cabinet?

[Bear]

Purely aesthetics. I thought that the roundover passed high enough from the tweeter that it wouldn't have too much impact on the sound.

Has there been any testing on at what distance does a variation not exist at the edge of the cabinet?

You can play around with a baffle diffraction simulator (e.g., BDS is Excel-based or Edge is stand-alone). I'm not sure that either can model that type of edge treatment. I think both assume that a given face is uniformly chamfered, rounded or "square" (deep faceting like with Avalon-style cabinets are also not modeled well, though BDS probably comes closest).

[Ray_D]

I'm curious: why did you stop the roundover short of the ends? On the woofer side, you probably won't get too much diffraction, but on the top near the tweeter, the pointed corners will almost surely be measurable (potentially audible to a non-trained ear). This is less relevant for surrounds, but if you go to multi-channel music, it may bug you later on down the road...

Hi Bear

I think that is unlikely. It is a very small angular subtense. I think edge diffraction is overrated in general. Most simulations are on-axis only and most listening is off axis which changes the effect. I don't think this is worth worrying about.

Regards

Ray

[joeybutts]

YES!!! Finally! Crossover parts will be here next week!! Sweet victory!

[joeybutts]

Got one enclosure wired up and playing.

I am so embarrassed that I am going to be having such amazing monitors as my surrounds. It is complete and total overkill and in my opinion maybe a waste of ability. Super clean. SUPER clean. No one should ever hesitate to build these. Ruler flat response. I am not exactly a fan of that type of eq but makes it easy to adapt. It is so easy on these to hear what was actually recorded in the studio by switching between different albums.

Most hip hop is recording trash. Sounds terrible on these. As soon as you put in something of a real music nature, not purely artifiical, they are UNBELIEVABLE. Just listening to one speaker I got goosebumps. Chills. I was moved. I may bring these to the meet for people to hear. The only negative is their size. Real big bookshelves.

I'll get an actual review up when I get the other one done tonight.

[---k---]

So, have you finished the finishing on your Khans yet?


Glad to hear you like them. One of these days, you should line them up all side by side, invite some people over and do a throwdown. Would love to see people's impressions of each.

[WilZirkle]

:lol:

[joeybutts]

I know Ryan.....I know...... I have 5 projects sitting naked. Full HT setup, Speedsters, Needles, and soon subwoofers. Trying to save for the last amplifier I need for the HT (pray I get it next month) and then will begin finish. Though I have been leaning toward painting the cabinets. 8O

Don't start Wil. :P If you ever want to make the less than short jaunt down to the Hampton Roads area to give a listen let me know.

[cjd]

Guess it's time to revisit the Khanspire crossover. Your review of just one of these was more ebullient than your review of the Khans... so much to do!

Glad you're enjoying it all so much.

[WilZirkle]

Hampton Roads, that's a haul, ~4 hours. Doubt I would be doing that any time soon but thanks for the offer. I've got most of my Kahn parts, and now you have cjd talking about redesigning the crossover...grrr. I guess I should relax though its not like I am rushing to get anything done, I only made two cuts on the MDF for my sub woofer this weekend.

[joeybutts]

cjd - I think my reviews were on the same level! I eve nreturned two or threetimesto fill in more review! Are you really going to revise the Khan crossover??? ugh. Please no.

Yeah, I saw ~4 hrs and that's why I said less than short. Good to hear you have the parts and are planning on starting soon. Mine took me quite some time, so no worries. Always amazed some of these guys get them done in a week.

[---k---]

He was joking on all fronts. Your reviews are just fine. There will be no crossover revisions. There is nothing left to extract out of these drivers. Any possible changes would be for personal preferences, which is likely better explored by the end user.

[joeybutts]

I figured he was, not 100% sure though.


Wrapped up the other loudspeaker last night, though couldn't really give them a thorough listening. Very quickly though, they have a very similar voicing to the Khanspires, but with some reallllly slight differences. I will double check these thoughts when I get to give them a thorough comparison. For my tastes, the Khan's edge out the RS22528A's by a small margin, and mostly due to the more capable ability to play the lower octaves. If crossed at an HT high pass, it would be a tough decision.

The average listener would have a tough time distinguishing the differences between these and the Khans and I think the Dayton RS Center. Granted they are of the same drivers, but the crossovers are all a bit different.

These are going to be some amazing surround speakers.

I am thrilled I went way overboard on all these builds, as I feel it has translated well to an amazing product that I could never afford at retail.

[---k---]

It's good to hear how similar they are all sounding. I toss around the notion that the NatP, ModulaMT, CJD RS150 MTM, KhanXXX, and MarkK's RS225 are all use the same drivers and are all based on a flat frequency response that they must be similar enough... But, it is never so simple. I'm really really have a little confirmation. Now you just need to build a pair of NatP.

Also, keep in mind that positioning is going to have a big role in the sound. Also very slight differences can be attributed to tolerances in the parts or stuffing.

Probably not enough to get excited about, because your probably going to put these in a room and run Audyssey and have it making all sorts of changes.




(Sidetrack - I do use Audyssey. I think it really helps clean up the low end. I wish I could tell it not to touch anything over say 300hz, but my Onkyo doesn't have that option. But, I can't hear that much change in the upper end.)

[cjd]

I tried the eq on my emo. The result sucked. So I pulled out the laptop and did some sweeps without the emo and scary flat response. No eq. In room. In walls behind the screen. So font assume it will help. Verify it.

Also I seem to have lost a post where I confirmed I was joking (probably. Really. Yup.) about a crossover revision. Silly phone.

[WilZirkle]

i knew he was joking too!...I did! Well ok I was a little worried.

Please don't encourage him to build anything else with my luck I will have finally started building boxes and then Mr. Butts will be raving about how much better his new build is...sigh

Wil

[joeybutts]

i knew he was joking too!...I did! Well ok I was a little worried.

Please don't encourage him to build anything else with my luck I will have finally started building boxes and then Mr. Butts will be raving about how much better his new build is...sigh

Wil

I do have some projects in the wings...... :

[joeybutts]

Quick pic -

[WilZirkle]

please have a shirt on