AVS Forum banner
  • Get an exclusive sneak peek into our new project. >>> Click Here
  • Our native mobile app has a new name: Fora Communities. Learn more.

Just pulled the trigger on the HTM-12's for L/C/R and I'm excited

7558 Views 137 Replies 24 Participants Last post by  mtbdudex
I just pulled the trigger on the HTM-12's for L/C/R in my basement theater. I'm incredibly excited but so very nervous at the same time because I've never done anything like this before. Unfortunately they only had one pre-built crossover available in stock and so I opted for three PCB's and I'll try to solder them myself.

I'll be replacing my Klipsch KM-4's and KM-C but I'll be using my Klipsch KM-2's (surrounds) for a while until I determine what direction I want to go with those. To power it all I'll be using my Onkyo TX-NR809 but I'll be replacing it soon'ish with a Marantz so that I can connect my 4k projector to it along with a few other components. Right now my Onkyo is only good for sound. The Projector is directly connected to my Sony UBP-X800 with HDMI audio out to the Onkyo.

I went ahead and ordered up some Titebond, a glue brush and a lot of clamps. One thing I forgot to get though was the wire terminals but not sure what direction I'll go with those yet. (binding posts, terminal cup, speakons or etc) but simple is better. All of my wires currently are banana plug. As for the stuffing, I think I'm going to try the denim. I'll need to get that on order also along with some spray glue I think. And, I'll be painting them black with DuraTex. Not sure what else I'll be needing.

Unfortunately the bottom of my 135" screen is 23.5" from the floor and so I'll have to raise it up just above the top of the HTM-12. And thinking about it, now I guess I'll have to make some stands to bring them up to ear level.

And once I FINALLY get them finished and set up and working properly I want to try my hand at REW.

I'm super stoked and just hope I don't mess them up and that they sound quite a bit better than what I have now. I've never heard any other home theater system other than my own so I have no idea what to expect. If this works out well then I'll be needing garage speakers, L/C/R for our upstairs TV and then I'd like to do some for our kids. :D
See less See more
  • Like
Reactions: 5
1 - 20 of 138 Posts
I haven't heard the Klipsch's but I do have HTM-12's for LCR and I love them. Crisp and clear no matter how much you turn it up.

For what it's worth, I went with terminals for banana jacks rather than the terminal cup. I saved myself having to cut a hole for the cup. Denim on the inside. I also soldered the crossovers. That really went pretty easy, just make sure you've got a decent soldering iron, some needle-nose pliers, and wire-cutters to cut the leads. The right tools make that job a piece of cake. DIYSG has documented the crossovers well enough that it would be hard to mess up. Enjoy the build!
Jealous. Good luck with the build!
I had my xo's assembled by @mtg90 several years ago. Not sure if he still does that for solder-phobes like me, but you can ask.
Have fun.
  • Like
Reactions: 1
You will have a great experience of the build and implementation
and fun

if you put the xo board edges on the edges of some 1 x 3, with small screws
you can just poke the components in,maybe on a dab of hot melt,
flip it over and solder in place- just ask questions

i replaced my klipsch F3 towers with the f15's, and 3 different klipsch cc's with the 88 special
and then the surrounds with more 88 specials

I got my 6 pack of denim from HD- cost effective , you may need to order it delivered to the store

i tried spray glue for the denim. you will have to work outside.
get your piece pre-fit if you insist on using glue
an electric staple gun is the real answer.
don't want to buy an electric staple gun, for like 1 project?
get all 3 cabs ready for denim install. all pieces pre-cut and pre-fit
buy the staple gun and staples, T-50's probably and get 1/2".
have a stapling orgy.
take the gun back the next day . .

as for speaker stands
do some geometry about seating distance, ear height
some elevating angle under the front edge of the speaker may be all yo need.

You will be so stoked when you fire up those 15" SEOS horns

depending on separation of the L/R, mine in the pic are 66 -72 C2C depending on toe in,
the stereo imaging will blow you away

practice some dry fit of the flatpacks

and ask questions


See less See more
practice some dry fit of the flatpacks
And don't overclamp - use lots of clamps, but not a lot of force.
  • Like
Reactions: 1


See less See more
jcmccorm - Thanks for the info. I think the separate terminals will be the route I take for that. I just don't want to drill a large hole in the boxes. And since they will be used strictly in the theater I'm not to worried about aesthetics.

Mocs123 - Thanks! I've been jealous for a few years but finally have enough saved up to do the deed.

LastButNotLeast - I saw that video out there on the diysoundgroup site that shows how to solder these. It was that video that made me decide not to wait around for the pre-assembled crossovers. It looks relatively easy so long as I take my time. And thanks for the advice on clamping. That's one area where I would have messed up. I wasn't sure how hard you had to clamp everything down. I'll clamp it but not ape it.

asarose247 - Thanks a ton for the info on installing the denim and stands. I do have an electric staple gun so that will make this easier. By the way, my L/R will be about 130" center-to-center. It's a pretty wide sound-stage. Hmmm, and after looking at your clamp pictures, it would appear I need to buy more clamps. :D And I am ok with that.

Ok, got a few questions:

1) What kind of solder should I use for the crossovers? Normal cheap solder with a flux core or a nice silver solder with no flux?
2) When installing the denim, can I cover up the crossovers with it or should I make a notch in the denim in the back of the cabinet for the xover?
3) Do I need to prime the surface for the DuraTex? Or just a good sanding and then straight to DuraTex will be fine?
4) In some posts I see that some people dilute the DuraTex with water? Why is that?
5) And for the internal cabling of the crossover to the speakers and binding posts I assume 14-gauge would be fine?

Thanks again everyone for the help on this. It is Hugely appreciated.
See less See more
I'm an ex-painter , residential, heavy industrial, rental pits,
and know when to finesse extra effort for finish

my own stuff- gets primo TLC

cabs primed first with flat black can reveal aesthetic compromises to deal with

for simplicity, sure, just gob on duratex, that's what it's formulated for and why it's $70 / gal.
it's a coating . . big difference

extra time on prep work = nicer look, even if behind screen

priming also gives more time to work the Dtex. it will cook off quickly- hence the thinning
usually for me done on cooler days and out of the sun and wind
and being thinned. a finer more flowed down surface, you have more time
i have a burned out 1/2" weenier roller just for that.
i have a older cup gun for spraying but that can be more work than it's worth.

the semi basketball pebble finish has a good feel, looks clean and tight and dusts / cleans more easily
than heavy texture using the dtex supplied hedgehog roller

at 130" separation, you will experiment with toe-in

get your REW tutorial downloaded


See less See more
Thanks! I will prime first and then dilute for a more smooth finish. Do you think I could use a high density foam roller (like you might use when painting cabinets) for a near smooth finish with the Dtex?
based on my usage of a foam roller

you will find that even thinned, dtex has "body' and not much "flow"

you could add an acrylic flow enhancer it's out there

but youwill see that finessing out the bubbles after an initial roll out
will demand a v-e-r-y lite touch re-roll to "pop" them - rolled with just the weight of the roller
and rolling both ways can help with the appearance of "streaks'
that stuff cooks off quick and a thin coat even quicker- hence a cool day/ area. no sun. no wind, dust free area
a flat surface with boogers is a fail . . .

denim can go over the xo's, which can be on standa-offs for the soldier clearance

14 gauge is on the cusp of overkill

roll the primer- thinned, with a low texture roller, sanding out texture is avoidable

many paints now come with primer in them
heavy coats are a biotch as the total dry time can be a few days based on weather humidity, etc.
sandpaper will gum up - pronto

a plain acrylic primer is what you want

or KILZ will prime, dry hard but light coats, multiple

the baffle- rattle can kilz- depends it you like texture or not- MDF is the pits - multiple light coats, sanding- be patient
but it will seal that mdf, no burn thru for the top coats

all my baffles are rattle can / pot gun sprayed, a satin oil-rubbed bronze. BC

there are exception, compromises

for giggles

my 88 Special surrounds- rattle can baffles- satin dark garnet metallic-duplicolor auto - chrysler color- BC

keep asking questions- get stoked

the HF F clamps are much better than the squeeze handle ones
notice my blocking wrt to the baffle attachment- denting MDF , or nail holes- it just sucks



See less See more
I know you bought the flatpacks- they are "silly smart"

off thread

I asked mgt90 about the htm12's for possible extra bottom , re cab re-dimensioning- but same baffle

"If the HTM-12 was built as 18"w x 25"h x 18"d it will give an F3 in the upper 40's and in room should give decent extension and output down to the low 40's upper 30's. Ports for this modification do not need to be changed from the 3" stock length."

I would want my 7 channel bed-layer all to have 15" SEOS horns . . .

what could possibly go wrong ?

just throwing that out there for others who may be thinking . . what if?

back to being on topic
See less See more
Thanks again asa. I think maybe I'll practice priming and dtex'ing on some scraps first to try and find the texture I'm after. I may go with a larger roller just to keep seams to a minimum. I just want them to blend into the dark as much as possible since they will be sitting next to my screen.
get your REW tutorial downloaded
and a UMIK-1.
and a UMIK-1.

Yes. I definitely need to get that on order. Been sitting in my cart for a few months now. Just keep finding other stuff to buy.
congrats op, im currently putting mine together right now. i hope im not highjacking your thread but i have a couple questions too if anyone can help. I have the walmart matress topper and diysoundgroup FAQ said its an ok alternative but does it do anything to the sound quality? also 2nd question is i bought nuetriks connectors for my htm12s, is there anything wrong with that as i see most builds are bind post, thanks and congrats again OP, i just finished building my crossovers and speakers sound great when i tested to see if i did them right, sure they'll sound way better in their boxes but i've never soldered anything before. i just bought a cheap 19$ solder set on amazon and it does the job if your only gonna solder these 3 speakers
While putzing around on the DIYSG website I saw some speakers that were painted exactly like I want.
And so I won't be going with DuraTex.

Since I won't be receiving the speakers for another 2-3 weeks it will give me time to get all the little things together that I need to finish up these speakers.

Here's the paint process that I found from mtg90 that I'll be using:

1) 3 - 4 coats of sealer primer (Zinsser FastPrime 2) with light sanding between coats.
2) Then two - three coats of flat black (Conco 9500) no sanding between coats, all just rolled on with 6" fine foam roller.

They look great and should blend into the background once the lights go down.

valleyslim - No problem with hijacking. I feel that if the questions stay mostly true to the topic and speaker model then it's all good. Oh, and I've got me a good soldering iron. Just trying to figure out now exactly what brand and or type of solder to go with on these crossovers. Update: Going with Cardas Quad-Eutectic solder.
See less See more
Great choice for your main speakers, you're going to love them. If you aren't in a big hurry, just take your time and set up an assembly line for the crossovers. One night while watching TV I did all the board layouts, and hot glued the components. The next night I soldered. It's really not too hard, and you'll get better as you go. Last rule: post pics!!
  • Like
Reactions: 1
Thanks OJ Bartley! Oh by the way, you used normal hot glue right? Nothing special with it?

I'm really excited to get started on these. I'm going to do all of the crossovers like you suggest
but then do just one speaker at a time so if there's anything I fudge up it will only be on one
and not the rest and use the knowledge of what not to do on the next.

That brings up a question. When I glue these cabinets together I'll be doing it in my garage.
During the day time the garage temps will be anywhere from 80* - 90*. But during the night
time hours the garage temps will drop down to possibly high-50* to 60-ish*. Will those low temps
affect the curing time and / or strength of the glue?
Just standard hot glue. Run one bead down the center of the long axis of each component and set it down on the bead (make sure you feed the contacts through the holes before pushing down). Works a treat.

You won’t have problems curing at those temps.

Sent from my iPhone using Tapatalk
1 - 20 of 138 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.