Where to begin??

[Swerd]

And how do the crossovers get wired together?! Hope I can find a good thread on someone that's built these!? My knowledge of crossovers is minimal at best ! Maybe time to become a member of the partsexpress forum?

As part of their effort to sell this kit to newbies, Parts Express has videos for cabinet and crossover board assembly!. As you get to that part of the job, if you have questions, ask us here . I haven't seen the instructions that come with the kit, but I expect Parts Express did a good job with that.

One other question, does anyone have pics of their cabinets w/ grills? I see all kinds of speaker kits and none of them have grills. Just curious to see how the grill frames are made and looking for some different ideas for how they fit the speakers.

For grills, use thin plywood or pressboard, ¼" or less. Parts Express sells grill cloth, plastic grill attachment doohickies, or small magnets. Make one large cutout opening for the all drivers, paint it black, and use spray adhesive to attach the grill cloth. If you want to get audiophile extra credit, use a round over bit to take the edge off the inside of the cutout opening.

I like using the small magnets to attach the grill to the cabinet. Before cabinet assembly, bore 4 holes large enough for each magnet in the corners of the grill board, and epoxy them in place. Bore 4 more holes for the magnets in corresponding positions on the back side of the front panel (often called the front baffle) and epoxy the magnets into the holes. Make the holes deep enough so there is roughly ¼" of wood remaining between the buried magnet and the corresponding on in the grill. When you're done, you'll have grills with invisible attachment hardware. If you're going to veneer the cabinets, you can bore the magnet holes into the front of the baffle, spackle & sand as a final fill to cover the holes, and veneer over them.

Those plastic bits also work, but they are visible and can break off.

 

[mattsk8]

I like using the small magnets to attach the grill to the cabinet. Before cabinet assembly, bore 4 holes large enough for each magnet in the corners of the grill board, and epoxy them in place. Bore 4 more holes for the magnets in corresponding positions on the back side of the front panel (often called the front baffle) and epoxy the magnets into the holes. Make the holes deep enough so there is roughly ¼" of wood remaining between the buried magnet and the corresponding on in the grill. When you're done, you'll have grills with invisible attachment hardware. If you're going to veneer the cabinets, you can bore the magnet holes into the front of the baffle, spackle & sand as a final fill to cover the holes, and veneer over them.

Those plastic bits also work, but they are visible and can break off.

Thanks for all that. Where's the best place to go look at pics of DIY speakers? I did order up today. I'm in MI and they come from OH so should see em in a few days...

 

[mattsk8]

That was fast! Stuff all showed up today. Now off to the drawing board...

Why use those finish screws to screw the cabs together and not finish nails w/ a nail gun? Just curious. I always used finish nails when I did sub boxes. I found early on that even if you predrill, when you put the screws in it tends to split the mdf. Finish nails are far less likely to do that and after gluing and clamping you really wouldn't need the strength from the screws.

Also, I read on one guys build that he made his box longer to accommodate a cavity in the bottom for the crossover so that it didn't impede w/ the acoustics of the box. Only reason I'm asking is I'm wondering if this is necessary. They don't show an ideal place for crossover mounting in the video. I've also read these tend to be a bit top heavy so adding 4" to the height for a crossover cavity would not be ideal IMO. Just looking for suggestions. Thanks!

 

[Swerd]

Why use those finish screws to screw the cabs together and not finish nails w/ a nail gun? Just curious. I always used finish nails when I did sub boxes. I found early on that even if you predrill, when you put the screws in it tends to split the mdf. Finish nails are far less likely to do that and after gluing and clamping you really wouldn't need the strength from the screws.

Nail work, screws work, and so does glue and clamps without nails or screws. Use the method you prefer.

Also, I read on one guys build that he made his box longer to accommodate a cavity in the bottom for the crossover so that it didn't impede w/ the acoustics of the box. Only reason I'm asking is I'm wondering if this is necessary. They don't show an ideal place for crossover mounting in the video. I've also read these tend to be a bit top heavy so adding 4" to the height for a crossover cavity would not be ideal IMO. Just looking for suggestions. Thanks!

No this isn't necessary. It was just one guy's way of having fun. It allows easy access to the crossover if changes are needed.

You can mount the crossover almost anywhere inside the cabinet. Avoid blocking the inner opening of a port tube if the cabinet has one, and avoid mounting it too close to a woofer's magnet. The magnetic fields of the woofer's magnet and the inductor coils might interfere with each other if they are closer than roughly 4". That shouldn't be a problem in a tower cabinet.

It makes sense to me to mount the crossover board close the binding terminals or on the floor of the cabinet. The limiting factor may be a place where you can easily reach.

 

[GranteedEV]

I do like the idea of raising the tritrix by 4" with a crossover stand. That's moreso because i feel the tritrix tweeter is a bit low for an MTM

 

[mattsk8]

Think I'll stick w/ the 36" just because of what I've read about em being top heavy. I might raise em by getting creative w/ a base of some sort, but I don't want to make the actual cabinet taller. Maybe make a base that's 1 1/2" thick and a bit wider than the speaker and fasten it w/ 4 1" or 1 1/2" diameter dowels that are 2" long. That would also give it a bit wider footprint so it's not as likely to fall over.

One more question before I begin... Would acoustic foam work better than the hollow fill (pillow stuffing) that comes w/ them? Given the design of the (guess you could call it a port), I'll see all the white hollow fill through the port and I think that would look bad.

If acoutstic foam will work, how do you figure how thick you need?

 

[Swerd]

One more question before I begin... Would acoustic foam work better than the hollow fill (pillow stuffing) that comes w/ them? Given the design of the (guess you could call it a port), I'll see all the white hollow fill through the port and I think that would look bad.

If acoutstic foam will work, how do you figure how thick you need?

I'd stick with the pillow stuffing that came with the kit. Acoustic foam works OK to line ported reflex cabinets, but transmission line cabinets need a defined amount of stuffing inside. The website that describes this design gives directions about the stuffing:

I used polyfill to stuff the lines, but you can use fiberglass, Acousta StufT, or whatever strikes your fancy. I found that a light to medium fill behind the drivers and a medium to heavy fill from below the drivers to the terminus gave the best response for my preference in my own listening environment. Start out with moderate amounts of filling material per enclosure and stuff to taste.

See the cabinet drawing.

If seeing the white stuffing through the opening in the back bothers you, try stuffing from behind the drivers (the front section) down to the bottom, but not in the space between the bottom and the rear terminus opening.

 

[GranteedEV]

looking at the graph:

They don't seem top-heavy. They may even be on the laid back side depending on what the off axis response and your room are like. Perhaps in a reflective room they may be top heavy but I don't see that as a function of the tweeter.



He does give an alternate 48" design on his site

 

[mattsk8]

I'd stick with the pillow stuffing that came with the kit. Acoustic foam works OK to line ported reflex cabinets, but transmission line cabinets need a defined amount of stuffing inside. The website that describes this design gives directions about the stuffing:



See the cabinet drawing.

If seeing the white stuffing through the opening in the back bothers you, try stuffing from behind the drivers (the front section) down to the bottom, but not in the space between the bottom and the rear terminus opening.

Thanks again for all the info!! I think I'm ready to begin. First thing I'll do is assemble the crossovers then build the boxes!

 

[mattsk8]

I saw that. What would be gained w/ the 48" verses the 36"?

 

[GranteedEV]

I saw that. What would be gained w/ the 48"?

mainly what I was refering to earlier, the tweeter would be ear height.

Remember, in an MTM speaker the top and bottom woofer are meant to reduce to the tweeter's off axis interaction with the ceiling (and floor). But if the speaker is too short than it's also going to hurt fidelity. You'd be surprised how different an MTM sounds vertically off axis. And with a 36" design you may actually be sitting off axis. I know where I sit, my ear along is about 36-38" off the ground. If that's the top of the speaker, then the tweeter's only like 26-30" off the ground, or about 8" below ear level. The top woofer will prevent me from being on-axis to the speaker unless I hunch down. Even if the speaker has good horizontal off-axis response, it's designed to have poor vertical dispersion! You can always play around with toe-in if the speaker sounds bright, but toe-up isn't quite the same.

For a 36" tall speaker I'd want a TMW tower not an MTM.

 

[mattsk8]

mainly what I was refering to earlier, the tweeter would be ear height.

Remember, in an MTM speaker the top and bottom woofer are meant to reduce to the tweeter's off axis interaction with the ceiling (and floor). But if the speaker is too short than it's also going to hurt fidelity. You'd be surprised how different an MTM sounds vertically off axis. And with a 36" design you may actually be sitting off axis. I know where I sit, my ear along is about 36-38" off the ground. If that's the top of the speaker, then the tweeter's only like 26-30" off the ground, or about 8" below ear level. The top woofer will prevent me from being on-axis to the speaker unless I hunch down. Even if the speaker has good horizontal off-axis response, it's designed to have poor vertical dispersion! You can always play around with toe-in if the speaker sounds bright, but toe-up isn't quite the same.

For a 36" tall speaker I'd want a TMW tower not an MTM.

It may actually be worse in my situation because I'll be standing most of the time (pool table room). I've never heard them either way so I have nothing to go off but does making the box bigger change the bass at all?

Remember, in an MTM speaker the top and bottom woofer are meant to reduce to the tweeter's off axis interaction with the ceiling (and floor).

I wish I already knew that but the main reason I purchased this kit was it seemed a cost effective way to get my feet wet! I'll build these, see how it goes and along the way grab all the research I can and try to learn!

 

[GranteedEV]

It may actually be worse in my situation because I'll be standing most of the time (pool table room). I've never heard them either way so I have nothing to go off but does making the box bigger change the bass at all?

If you compare them, you'll notice the 36" version has a bit of ply going vertically up at the back to make the transmission line long enough. The 48" version is "open" at the bottom back corner on the other hand. This should mean the tuning is identical. Because the terminus is lower, the line is the same length, just taller.

 

[mattsk8]

If you compare them, you'll notice the 36" version has a bit of ply going vertically up at the back to make the transmission line long enough. The 48" version is "open" at the bottom back corner on the other hand. This should mean the tuning is identical. Because the terminus is lower, the line is the same length, just taller.

All right, based on that I'll do the 48" version. Think I'm ready for the build. Thanks for all the input!!

I do have one more question before I fire up the soldering iron and saw, do I need to worry about enclosing the tweeter in the cabinet independantly from the woofers or will this not matter?

 

[Swerd]

I do have one more question before I fire up the soldering iron and saw, do I need to worry about enclosing the tweeter in the cabinet independantly from the woofers or will this not matter?

The Dayton Silkie tweeter comes with a built-in rear chamber. All you need to do is hook up the wires and flushmount it.

http://www.parts-express.com/pdf/275-075s.pdf

Its a remarkably good sounding tweeter for a very low price.

 

[mattsk8]

This is 4 different designs. I can't see the difference between the first 3. What are the differences? Also, in the first and last design it shows a line that's not an MDF board on the back of the cabinet. What's that line?

I kind of like the idea of the fourth (furthest to the right) design w/ the front vent. Would covering that w/ grill cloth impede performance and also, what changes acoustically by moving the vent from the rear? Would this change the bass of it based on the location? I'll have the rear of these near a wall.

The speakers mount in the front baffle in the same location off the top as the 36" correct? Additionaly the braces would go in the same basic locations, right?

The only dilema I could see w/ these is my cat climbing in the vent hole in the back (or front, depending on which design)!

 

[mattsk8]

It would seem as though I've reached the limit on dumb questions . I'm just nervous to build the 4' because I'm not sure how the front port cabinet would sound compared to the rear port. If I could get that question answered, I'd really appreciate it! Plus, thanks for all the time you guys have given me so far!

 

[GranteedEV]

This is 4 different designs. I can't see the difference between the first 3. What are the differences? Also, in the first and last design it shows a line that's not an MDF board on the back of the cabinet. What's that line?

I don't know, I think your best bet would be to ask Curt as he's the one who made the diagram

I kind of like the idea of the fourth (furthest to the right) design w/ the front vent. Would covering that w/ grill cloth impede performance and also, what changes acoustically by moving the vent from the rear? Would this change the bass of it based on the location? I'll have the rear of these near a wall.

Give a grille a shot, you can always take it off and compare.

The speakers mount in the front baffle in the same location off the top as the 36" correct? Additionaly the braces would go in the same basic locations, right?

The only thing changing is that the backwards taper at the bottom. The top should be identical.

The only dilema I could see w/ these is my cat climbing in the vent hole in the back (or front, depending on which design)!

Hehe. Perhaps a pair of bar grilles like the ones funky waves uses:

http://www.funkywaves.net/catalog.cfm?item=fw_15_2

?

 

[mattsk8]

Thanks for all that!! I think I'm just going to make the front vented 4' cabinets. I'll use that bar idea but put them just above the port on the inside of the cabinets so you don't see them. That way the cat can't get in there to chew on speaker wires! I couldn't email Curt because his email thing on his website won't work because my computer said I have to install some special email program.

I'll start a new thread documenting my progress! Huge thanks again to everyone for all your help !!!

 

[GranteedEV]

The last thing I'll say to you is:

Do not expect these speakers to be magical. They may not have the instant appeal you may subjectively associate with a "good speaker" Live with them for some time and try to rediscover your music and even movies. What you may initially think as lifeless you may eventually find to be truly organic. Expect these speakers to be different from what you may be currently used to. Try instead to find the nuances that aren't hidden rather than the types of things which are often thrown at you with reckless abandon but here seem tamed and under control. What you will likely initially perceive as the speaker doing uncomfortably differently will more than likely just be as close to real as the drivers' capabilities as is realistic.

And then you can move them to the rear as surrounds when you build something uber awesome for the high SPL levels!!!