AVS Forum banner

DIY Sound Group HTM-12 Build (UK BUILD)

35K views 180 replies 21 participants last post by  mkohman 
#1 ·
Hello all folks across the pond ;), I have decided to go down the DIY route myself.

Big thanks to the other HTM-12 owners on this forum who have inspired me and posted very informative and helpful build threads!

This will be a slow progress build and will take time no doubt, however I will definitely be posting pics and updating this thread as and when things are moving along.

I have placed my order in just now for 3 x kits of the HTM-12 and the pre assembled crossovers which has cost me $970 or £750 and will get my MDF for the cabinet build cut tomorrow or in a couple of days when I am off work... I've also just ordered some more clamps from Amazon so will await for all to arrive before I commence.

Will hopefully update with some pics during next week
:)
 
See less See more
1
#3 ·
congrats from me too . .

which glue will you be using and will you be using a brad nailer?

using mdf you'll want to stabilize the panels for straight and square while the glue sets up

waiting to see the pics . .
 
  • Like
Reactions: mkohman
#5 ·
Thank you @asarose247 I don't think I will be using brad nails as I don't have a brad nail gun.. I was looking to get the Ryobi Air Strike for this project but others have advised just to glue and clamp as the glue I am using "Gorilla" is more than sufficient for the task. I did a test with the glue on some scrap mdf and it was super strong. When I tried to seperate the two pieces I couldn't I forced it and it ripped the mdf off but the joint was still intact :) so I think the glue will be the way to go for me with plenty of clamps and a band clamp too.
 
#7 ·
i have a few sets of these: http://www.rockler.com/universal-fence-clamps-with-clamp-it-square

that can keep you on spec while the glue sets up

a few (4) ratchet clamps can be quicker for set up with the just the plastic parts

and Rockler does sell a set like this: http://www.rockler.com/clamp-it-assembly-square-6-pc-kit

but mainly you can get by (i.e. > WANT!) with just the corner clmaps and get cheaper just a good clamps off amazon or whatever your resources are

since the HTM12's aren't so large I suggest 2 of those corner clamps

as the glue can slide you out of spec too, think of using stops blocks, etc. so things stay put . .
 
  • Like
Reactions: mkohman
#8 ·
i have a few sets of these: http://www.rockler.com/universal-fence-clamps-with-clamp-it-square

that can keep you on spec while the glue sets up

a few (4) ratchet clamps can be quicker for set up with the just the plastic parts

and Rockler does sell a set like this: http://www.rockler.com/clamp-it-assembly-square-6-pc-kit

but mainly you can get by (i.e. > WANT!) with just the corner clmaps and get cheaper just a good clamps off amazon or whatever your resources are

since the HTM12's aren't so large I suggest 2 of those corner clamps

as the glue can slide you out of spec too, think of using stops blocks, etc. so things stay put . .
Cheers for that. I actually bought a band clamp and some 24" quick release clamps along with a couple of 12" quick grip clamps and 4 x corner clamps.. I think that should be enough for the build but will buy more if necessary.

I think the method I will use is build the top, bottom and sides first, glue them all together, then glue that hollow frame to the back panel. then glue in the horizontal and vertical braces. I am going to get my MDF cuts this week. :)
 
#9 ·
some, but not all , would start with sides 1 or 2 at a time being glued to the back

that way you have a better chance of keeping the sides all squared up 'cause the back is "square'

i wouldn't want to have to challenge the glues joints by maybe needing to handle squaring the assembled sides all at once to the back piece

it seems that controlling 4 sides at once wrt to keeping them all in the right alignment / place is more challenge than, for me and IMHO, than I would care to opt for

from my lessons in working with BFM plans, get each board right , 1 at a time and be sure to hit the mark . .

then get the next 1 right . . . .

and so on
 

Attachments

  • Like
Reactions: mkohman
#10 ·
Quick update.. I've just been to my local B&Q and the guy there was very helpful.. He cut all my pieces to exact measurements and now I have got them back home and doing a dry fit test before I glue the top, bottom, left and right panels together.. Here's a few photos.. Fingers crossed should hopefully go all well







 
#11 ·
It was a bit tricky with the band clamp lol but all ok now.. I have glued in the first one and applied reasonable pressure both on Band clamps and the quick grip clamps.. Any idea how long I should leave it in its clamp status before taking the clamps off? I mean I don't intend sticking the back facia today but I can then move on to the next one if I can remove the clamps.. I'll leave the clamps for a few hours or even till tomorrow no rush but I just didn't know how long is reccomended to leave them on.. Would appreciate some advice please..

Also the corners seem pretty flush and square as I used my square to check afterwards.. I cleaned the excess glue from the outside case to minimise any sanding later on in the build however left the inside with the excess glue as can be seen in the pictures... Hope this is OK to do?







 
#12 ·
Welcome to the club!!

You're off to a great start, they look perfect so far. Nice squeezeout inside to ensure a good seal, and square coeners. Don't need much else from an enclosure. I would be remiss if I didn't add my usual "you can never have too many clamps!" comment, but you can often manage with whatever is on hand. Looks like your band clamp is working nicely.

Keep at it, take your time, and enjoy the build! I'll follow along to see your impressions. These really are great speakers. I can't wait to get mine up and running in a proper setup.
 
#14 ·
Right.. Off to bed now guys, however I just couldn't sit still lol.. I figured the clamps had been on for over 11 hours so was safe to take off and glue back panel for the duration of the night so that's what I did .. Tomorrow I'll start fresh on the second box fingers crossed after a few things I have to do in the morning.. Will update with pics as I go along.. Good night all...







 
#16 ·
OTOH, if it ain't broken . . .
 
  • Like
Reactions: mkohman
#18 ·
nice "flow",
hope it inspires others to appreciate well applied basics begun with the end in mind

not every DIY project "needs" a Manhattan Project mentality

but it can be fun at times

especially when you get to fire them up . .
 

Attachments

  • Like
Reactions: mkohman
#20 ·
Today I managed to knock up the other two boxes.. Back panels glued and clamped.. Will probably leave the clamps on until tomorrow evening as I don't need them for anything else and once that's done I guess I'll need to wait for the front baffle and parts before I start cutting out and installing the vertical and horizontal braces into each box.. But this is the current situation as can be seen in photos below :



 
#21 ·
Thanksgiving not withstanding,

What about stuffing?
 
#23 ·
once you have location of the xo laid out,
IMO and experience reading around the farm , the roxul should be acousticallyadequate and as Erich might add a a generous handfull of polyfill gently but firmly around the horn

but


in my sound panel build, I always uses a sheer curtain material over either 703 and rosul for fiber control

in my various speaker builds needing stuffing I've always used the blue denim stuff, if only about 37+ mm, along with the poly , if needed

the denim doesn't have the "friability" , like asbestos, issues of the tiny fibers that make up roxul that might migrate into driver clearances, coils, etc. impacting, perhaps, performance and durability .

the denim can be stapled in, BAM!,


I used spray glue ONCE in my F15's . don't even think about it . . ..

I used 2" waffle foam in my 88 Special CC build.

HTH
 
  • Like
Reactions: Java and mkohman
#24 ·
once you have location of the xo laid out,
IMO and experience reading around the farm , the roxul should be acousticallyadequate and as Erich might add a a generous handfull of polyfill gently but firmly around the horn

but


in my sound panel build, I always uses a sheer curtain material over either 703 and rosul for fiber control

in my various speaker builds needing stuffing I've always used the blue denim stuff, if only about 37+ mm, along with the poly , if needed

the denim doesn't have the "friability" , like asbestos, issues of the tiny fibers that make up roxul that might migrate into driver clearances, coils, etc. impacting, perhaps, performance and durability .

the denim can be stapled in, BAM!,
I used spray glue ONCE in my F15's . don't even think about it . . ..

I used 2" waffle foam in my 88 Special CC build.

HTH
Thank you so much for your help .. Really appreciate it. Rockwool is out the question then lol :)
 
#25 ·
Evening all, I know it's not much to get excited about lol but thought I'd add a couple more photos of the current situation.

I've just returned home from work and removed all clamps from box 2 and 3 which have been in clamps since yesterday morning so probably about 30 hrs in clamps.. I think this is all I can really do now untill I receive the front baffle and drivers so that I know exactly where to glue in the braces... Anyhow that will be it for a while.. Catch you guys hopefully in a few weeks once I get my delivery and thanks for all the support so far :)





One thing I did notice is when I used my band clamp on the second cabinet I placed it in the centre so it has thrown out the panel by 1 cm.. as can be seen in the pictures below.. This has really upset me as I wanted them to be exactly 18 inches to couple up with the front baffle. Do you guys think I can resolve this issue by sanding the front baffle or is that not reccomended and shall I use filler or shall I just re do the cabinet for this speaker again.. It's heart breaking as I spent so much time and effort into doing them.. :(

 
#26 ·
well it's hard to see it, but 1 cm divided around the baffle is about too small (4mm to the left and right?) to put your knickers in a bunch
at this time

you'll have plenty to do so if that cab needs extra work , you can "just" plan to work around those extra steps while tending to the other 2

( maybe after checking for baffle fit, some tapered belt sander work just might do the trick . YMMV cause you have to look / live with it . .
you could start on the bracing configuration, at least thinking about, which I'm sure you already have . .

however, as a ported cab, thermonuclear resistant cab inertness should be kinda easy

the corners are some of the strongest points in the build !

it's the panels interior areas that you want to "hold fast"

the cab is not going to pressurize - it's ported , so

reducing the tendency to flex, of which there will almost none, is not rocket surgery

after looking at the dimensions of your build at DIYSG,

in the 2nd pic I used some 3" scraps of 3/4" ply and about 3 kreg screws and PL3 and pretty much ran down the center of each panel.

they ain't flexing. . or bulging apart from internal pressure
looks like i came just a bit over 3" from the corner junctions

be sure to include clearance for the ports wrt to stuffing

HTH
 

Attachments

  • Like
Reactions: mkohman
#33 ·
As I have now sold my much loved XTZ cinema speakers I thought I may aswell have a little fun and see what the new HTM-12 will look like behind the cinema screen.. Here's a before and after shot lol ;)

The 1 thing I'm ever so slightly worried about is the waveguide not being on the same level as my ears.. It's going to be slightly above what the m6's were but I'm sitting approx 5m away from my screen and the tweeter will be exactly bang in the middle of my screen so might be ok... I would appreciate any suggestions if you think I should or could do anything to change it up slightly only if necessary as I don't really want to spoil anything in relation to the screen wall.

Here's my m6's :



Here's the cabs of the htm-12 speakers ;)





 
#34 ·
HO! HO! HO! - way to go ..

the difference wrt change in ears vs. tweeter / horn centers height . .

how about a pic of the tweets for the existing compared to a shot of a 15" SEOS horn

could be revealing . .

those SEOS horns are some smart science, you may not have any issue due to the height change, if not extreme (whatever that is ? . .)

maybe you can get Erich / the designer to chime in . .

think of it this way . .

I replaced my F4Q4 surrounds with a pair of 88 Specials . . 4" horn vs. 15" horn

while it looks like bringing a knife to a gunfight , XT32 put the F4 xo at 40 and the 88 xo @ 100,

just part of the beauty of DIY . .

Tell Santa /Kris Kringle to hurry up with the kits already . . geeesshhhh!
 

Attachments

  • Like
Reactions: Jan3 and mkohman
#35 · (Edited)
Thanks for your help dude.. Much appreciated ;) .. I should be taking delivery between 1-4 Dec fingers crossed.. Shipito have already handed over to FedEx and I got a confirmation from them this morning so touch wood.. so far so good :)

Oh and as you asked.. here are the tweeters of my speakers I have just sold :(



 
#36 ·
TY for the pics, always good to see other things about how designers are thinking.

put that next to the horns . . . JS

this is just a question I'm not able to or interested in digging up and answer, for,
nor am I expecting anyone else to either-

but for what we can read and learn here at AVS and other places,

the element / issue of speaker design and apparent small size that come to mind for that speaker "comb filtering" ,

but if it sounds good .. so be it

https://www.google.com/search?q=Car...hUX-GMKHTxpANIQ9QEILzAC#imgrc=aOUoeru38OkKwM:
 
#38 ·
hopefully a layman's short version: common horizontal MTM can have comb filtering interaction between the different speakers if the spacing is un-optimized with regards to phase interaction for the output

I googled it myself and got < 400,000 hits and some good reading . .

HTH
 
  • Like
Reactions: mkohman
#40 ·
^ am exemplary example of meeting the DIY challenge

If thinking outside the box starts to gets to be problematic,

try flipping it over . . . (one of the can-do thinking mans options)
 
  • Like
Reactions: mkohman
#43 ·
very minor update :

Today I finished what I needed to do earlier then I'd anticipated and left me free for the mid morning, early afternoon.. I took the opportunity to try out my newly purchased Bosch Pex 300 random orbital sander on the cabinets.. Basically I wanted to smooth down the rough corners and excess glue, preparing them for the front baffle which will hopefully be arriving next week, fingers crossed..

Let me tell you.. I've never owned a random orbital sander but this little beauty is absolutely brilliant.. Such a beautiful machine and easy to work with.. I definitely reccomend anyone who maybe looking to buy one...

Here are a couple of closeup shots of the edges etc... I appreciate they will be filled and re sanded but it cleaned them and prepared them nicely for the next stage hopefully next week..







In addition to this I thought it would be good if I prepared the horizontal and vertical braces.. Clearly I have no intention in gluing them in before the front baffle arrives but again just wanted them ready as I had the time to knock them out today.. Hope they look ok? I think I may need to round the horizontal braces a little as they are maybe too square? Would appreciate any advice on this .. Thank you.











 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top