MarkK's Rs22528A as surrounds build thread

[joeybutts]

All panels were cut from 1/2" and laminated together to be approx 1" thick. All panels are laminated, I just need to cut braces and am waiting for Mark to confirm the layout dimensions for the baffle.

uhmmm....These are huge too.
First though, panels....



And then there were monster bookshelves. The baffle is on top for reference...

[HareBrained]

You're a busy boy, Mr Butts. Got any car projects in the works?

[joeybutts]

ahhahahahah You have no idea. 8)

I do, but it won't be for a little while. Gonna do the (and I'm serious here) final install in the mustang. Should be rather ridiculous when done. I've also been tossing around getting a new H/U, but one thing at a time.....

[ruseriousclark]

Those are some $$$ rear channels.

Built these a few years back. Excellent design. Sound and imaging is remarkable.

Please listen to them alone before relegating them to soley rear channel use. You'll be amazed how well they perform.

[joeybutts]

Those are some $$$ rear channels.

Built these a few years back. Excellent design. Sound and imaging is remarkable.

Please listen to them alone before relegating them to soley rear channel use. You'll be amazed how well they perform.

Oh really? I was wondering how they would perform, and hearing this makes me ecstatic. I'll def listen to them as mains prior to using them as rears. They can always be moved, purpose changed, etc.....

Plus it would mean I would need to find and build another design.......sigh.....
:lol:

[Mark K]

Oh really? I was wondering how they would perform, and hearing this makes me ecstatic. I'll def listen to them as mains prior to using them as rears. They can always be moved, purpose changed, etc.....

Plus it would mean I would need to find and build another design.......sigh.....
:lol:

Hi Joey,

The RS225 is centered on the baffle vertically, and the center of the RS225 is 6" above the bottom edge of the baffle.

The RS28A is offset 3/4" from the vertical centerline (one to the right and one to the left-obvious but lots of folks accidentally forget to mirror one.)

The RS28A center of the tweeter dome is 3" down from the top of the cabinet.

The PE baffle is the standard size for 3/4 cu ft non mtm box.

Hope that all makes sense...

[Mark K]

Those are some $$$ rear channels.

Built these a few years back. Excellent design. Sound and imaging is remarkable.

Please listen to them alone before relegating them to soley rear channel use. You'll be amazed how well they perform.

Thanks for the kind words!

BTW I lived in Lexington for 3 years from '95-98 when I worked at UK. Occasionally I wonder if I should have stayed!!

[joeybutts]

Hi Joey,

The RS225 is centered on the baffle vertically, and the center of the RS225 is 6" above the bottom edge of the baffle.

The RS28A is offset 3/4" from the vertical centerline (one to the right and one to the left-obvious but lots of folks accidentally forget to mirror one.)

The RS28A center of the tweeter dome is 3" down from the top of the cabinet.

The PE baffle is the standard size for 3/4 cu ft non mtm box.

Hope that all makes sense...

Thanks Mark! Much appreciated. And makes total sense. Hopefully get those knocked out this weekend.....

[joeybutts]

Baffles are cut out and laminated. Need to cut the bracing next.

[joeybutts]

The bracing is planned, Thursday it will be cut....

[joeybutts]

Brace complete

[joeybutts]

Bracing done!

[joeybutts]

Pics of one surround bracing channeling done.

[JonP]

Wow... double walls all the way around! Cool bracing, nice interleaving of the parts. Those boxes are going to be stiff, dead, and heavy... :T Watch your back!

I did a set of boxes the same (.75 cu ft) size, but 5/8" Baltic Birch (thinner and lighter per volume than MDF) only 2 layer laminated for the front baffle, and just a single height x width brace with much cutout. Even with the lighter RS180, they were still over 25lbs each when done. Wonder how much more yours will weigh?

[joeybutts]

Thanks Jon! I have no idea and haven't even thought about that! I'll try and get a weight today of these and my center channel.

[joeybutts]

Well, finally back up on this horse. Since I'm not having the surgery on my knee because my insurance told me I'm fat, I'm hoping to have these constructed by next weekend.

[bigbardmusiq]

I think i will build these one day, I love those RS225's!! is this a non-bsc crossover for on wall or in wall designs?

[joeybutts]

I think i will build these one day, I love those RS225's!! is this a non-bsc crossover for on wall or in wall designs?

I am not sure and you would have to speak to Mark K about that....

[Hunter12]

Mr Butts,

I was wondering if it is possible to build these speakers in 30 liter cabinets
or larger without having to change the crossover. Paul Carmody has a number
of TM designs that are housed in larger cabinets with increased bass and
the benefit of being able to stand on their own feet.

Thank you and good luck with your mini tanks.

[joeybutts]

Mr Butts,

I was wondering if it is possible to build these speakers in 30 liter cabinets
or larger without having to change the crossover. Paul Carmody has a number
of TM designs that are housed in larger cabinets with increased bass and
the benefit of being able to stand on their own feet.

Thank you and good luck with your mini tanks.

Hahahaha. Mini Tanks. I like that. :T

I do believe that you can alter the enclosure size to your liking and it will not require a crossover change, but will alter the low end extension. The only thing I am 99% certain is that you will need to keep the baffle alignment the same or the crossover will need to be tweaked a touch for optimal performance.

[Hunter12]

Thank you for anwering my question this has helped me a lot with
making my decision. I started with larger designs in mind and made
scale models out of cardboard to show my wife. The designs were
all too big for her so I stared making smaller and smaller ones until
she was happy. By this point my interest started to wain as I felt
like I had been castrated with a rusty spoon. These 8" drivers help
to make me feel like a man again which is good. With the other
midget speakers my wife loves I was starting to feel like a
girlyguy/metrosexual.

I took some time to view your thread and I suspect the inside of
your speaker cabinets are going to look better than the outsides
of mine, well done, superb job..

[BobEllis]

A little clarification - You can change the height to whatever you want, but keep the width and driver position the same. Be sure to model the drivers in boxes of the volume you intend. While you can get the RS225s to tune quite low, you'll run out of excursion if you try to get too loud if you try to make them act like subwoofers.

[Hunter12]

Bob,

Thank you, I think I understand what you are saying. I called Solen
intending to extend the SR71 cabinets to the ground similar to Paul
Carmodies Amiga/TRS 80 designs, Solen said it wouldn't work, woofer coudn't
handle 30 liters of air. I said okay and that was that. My intent was to
try and buy drivers that were made in the West (Norway I believe).
I like how we live and feel I should support our cause.

Then I found Mark K and Mr 8 inches, I like this idea a lot but just
want to avoid having to make speaker stands and using the 34 inches
of height to ones advantage. (my friends Totem Rainmakers have fallen
down twice and blown up twice, yes he smokes too much dope but
they dont look so good now, he paid $1000 Canadian 3 years ago)

Hope this makes sense, I just like the idea of 8" inch drivers in a TM
as does Troels Gravesson in his TQTWO or something like that.

Am I right in ordering the RS 225-8 or is it one of these two
RS 225-4/RS 225 S-8, this is how Solen lists them.

Thank you for your help, the French guy at Solen makes me look stupid
which I am when it comes to this stuff.

Maybe my question should be can this RS 225 in MarkK"s design be happy
in 30 liters of air? while keeping the width and driver position the same (thanks Bob).

Dayton states that the VAS (liters) is 37.5 for the RS225.

[cbark]

Hunter12,

Hoping not to take over joey's thread here, but you usually can make a TM a floorstanding tower by building the enclosure into two chambers. The bottom will be not integral to the tuning of the speaker because it will be sealed of from the upper speaker portion. This option allows you to make the enclosure teh size that you would like. I would model the size you intend first.

[Hunter12]

Cbark,

Thank you for your input. Your advice makes sense.
I need to buy a book on this or find a design that
needs no alterations. I still love the idea of a muscular
8" TM. Have no plans on giving up on my idea, to me
it makes sense.

[BobEllis]

The RS225S has been discontinued, substitute the RS225-8. The top end response is close enough to use the existing crossover, but take a look at box tuning. The T/S parameters are a bit different and you won't need quite as much box volume.

Thanks Cbark for adding the part that I forgot to post.

[fjhuerta]

That bracing is prettier than the veneer on my speakers!

[Hunter12]

Bob and Cbark,

Thank you for your help, I'm feeling more confident
about my plans and I will do some research regarding
box tuning.

[Hunter12]

Joey,

I'm keen to know why you chose a 8" driver for your TM, most people are using a 7" or smaller not sure why you are travelling on a different path. I realize you already have an association with 8" drivers from your D8's but these are not intended for mains from what I can establish. Hope this question makes sense.

Is MarkK's cross over as big as a laptop computer and does it cost more than
the drivers themselves? Good to know these things before it's too late.

How can you afford to build so many speakers and still have a girlfriend?

I have done some calculations on progressive resistance and have figured
out that by the time you have finished all these super heavy speakers
that you should easily be able to power clean and press your D8's, this
would put you into a "elite" strength category which is just short of
being able to wrestle with a Grizzly Bear, not bad.

[joeybutts]

Thanks fjhuerta! I've been under the weather as of late and haven't had a chance to work on these.

Hahhahaha. I like your style Hunter. I'm originally from Buffalo, NY, a short jaunt from Toronto.

I chose the Markk RS225/28A because all the drivers match up with what I will be using for my mains and center (Khanspires for mains and Dayton RS center channel, which have their own respective build logs here.) Also, I'm one of those guys that says go big or go home. : My D8's (which I am going to be trying sell shortly ) we're my first HT build after my HT subwoofer (which is now gone).

I was informed by someone that this design is quite good for an 8" 2-way, and could be/should be used as mains. I'd have to scrounge around to find it.

I haven't had a chance to pick up the crossover components yet, but by the look of the BOM, it seems that the board will be a small to medium size. I only see one large cap and no big inductors at quick glance......

As I've grown older, I've reduced the number of hobbies. So now I basically play sports, workout, work on my car and build speakers. And I let her know as soon as we started dating this was my passion. I lucked out and she understood. Oh...and this is part of why it takes me forever to get these projects done! :

I do workout's of a powerlifting nature. That's why I'm 5'7", 210, 14% body fat. I haven't maxed out lately, but by the percentage chart my five big lifts should be

Bench 330
Squat 465
Deadlift 475
Hang Clean 295
Leg Press ~1400.

Too bad I've been sick the last week.

[Hunter12]

Thank you for the answer, what I plan to do is just follow along with your project
and learn from you. I went to Markk's site and got very confused plus concerned
that his last update was in 2008. Plus I don't want to bother him until I'm 100%
sure that I'm proceeding with his speakers.

Very impressive lifts, you have been at that for years to reach those numbers. I got
onto Bill Starr's "big three" a couple years ago a made some good gains, my German
wife has terrible english she said you have become "the double" meaning bigger, yes
I had to buy new clothes. Problem with heavy squats and deadlifts is it makes you
insanely hungry the next day.

The confusing thing for me is that Troels Gravesson talks about smaller,lighter, faster drivers for the midrange of music and then he designs his dream speaker DQTWO or something with a large midrange driver not unlike yours. Okay, he had it specialy built for his "perfect pair" , but it aint small.

They say to get good at something takes 10,000 hours of focused work, my speaker
time is very, very low.

Get well and enjoy your project. (did you damage our knee while lifting?,
very dangerous if one looses ones focus with a lot of weight on ones
back)

[joeybutts]

Markk seems to be a well received and respected designer, so I trust the work he has put into designing this 8" 2-way. You don't see many 8" 2-ways due to complexities in properly fitting two drivers together that don't require laptop size crossover designs.

I don't think you should have any doubts in building this design, besides the fact that it REALLY stretches the term bookshelf.

I hurt my knee playing football. In the gym, ihave nothing but focus, technique, and intensity.

[joeybutts]

Bracing and one side glued together on both. Hopefully tonight I get the top and bottom on both enclosures. I'm building this full HT set clamp/glue, so it will take some time. Should have these just about ready for OC703 and putting in the terminal cup in the back.

Pics up tonight.

[joeybutts]

Clamps

[joeybutts]

Slow slow progress

[joeybutts]

Coming along......

[krips]

Those will be some sturdy and weighty little TMs when you're done.

[joeybutts]

Those will be some sturdy and weighty little TMs when you're done.

Oh....you better believe it.

I'm going to estimate them to end up around 50 lbs not even really thinking about it.... I'll try to weigh the enclosure some time this week.

[looneybomber]

I'm an EAS fan myself, but it's good to see you're taking MetRx. With those heavy suckers, you're gonna need it!

[joeybutts]

I'm an EAS fan myself, but it's good to see you're taking MetRx. With those heavy suckers, you're gonna need it!

HAHAAHAHH. No Metrx for me....just a calendar out of my M&F. But I've been prepping my whole life for this. 8)

Can't wait to get my Khanspires done that are built in the same manner. :twisted:

[joeybutts]

Got the terminal "cups" just about done. Need some detail work since my old but trusty miter saw isn't quite as precise as necessary. Going to pick up some belts for the belt sander shortly to clean up the mounting faces.

Parts for all five terminal cups cut and glued







Check out the awesome armchairs......





I wanted something different than just perpendicular to the cabinet and would streamline the cables coming out so that they were almost hidden so I went with a downward angled terminal style.





And here is an idea of what it will be like, using one of my waterlogged baffles I need to recut. I don't know if the pics really show it well but I tried.







Slowly but surely......

[joeybutts]

Terminal cups glued in. One of them almost done being sanded. Both done tomorrow and new baffles cut.

[joeybutts]

Picked up the 703 and made the new baffles. Just need to make sure that I don't have TOO much 703 in the cabinets. Can somebody give me guidance on if I need more/less in there? My biggest question is if I need more room between the motor of the woofer and that piece of 703 on the bracing.....

Owen Corning 703



Cut up and in!! If this checks out going to seal up the cab's and then just need crossover components and do the finish! WOOT!

[joeybutts]

Revised the 703 layout and amount, and am gluing on the remaining panels right meow!

[joeybutts]

Enclosures are together! Baffles are drying up and should be good by now actually. Both cabinets are fully sanded except for the baffle edges. Need to figure out any accents I want to do in the cab's if any and then all that is left is crossover and finish work. Crossover is easy, the finish.........

Pics maybe later tonight and also might weigh in the cab's for sihts and giggles.