Heissmann DXT-Mon-182

[ernperkins]

Having all your inductors in the same orientation can cause problems. Here's a helpful placement guide from Troels Gravesen.

 

[suttondesign]

Having all your inductors in the same orientation can cause problems. Here's a helpful placement guide from Troels Gravesen.

I placed them quite far apart except for one which is vertical. That is why I use a 12” board. One small one should probably be reoriented, as you suggest.

 

[suttondesign]

The crossovers in situ on French cleats, under the stair landing with the amps and Flex 8. Separated by more than 20cm.
The speaker wires will travel under a walnut-enclosed floor chase under the bookshelves in the living room/media room on the back side of the plywood wall to which the crossovers are affixed. I placed them up on the wall, up high and well away from the amps, to avoid any magnetic fields which could introduce hum. There's no electrical behind the plywood here.

 

[suttondesign]

First carcass in glue-up.

 

[suttondesign]

Setback. The veneered ply I glued to the MDF had such thin veneer that any amount of working it exposed crummy white wood below it, wrecking the walnut look. I've got to throw the boxes away and make the box up differently. I'll probably just spring for the solid since I'm going to use multiple ways of reducing resonances.

Oh well, all I lose is my time and another $100 in materials.

 

[Ktacos]

That's unfortunate. Happens to the best of us. Ever make two speakers to near completion only to realize you didn't mirror the driver offsets?

If you mean doing the whole cabinet out of solid wood it's not impossible but ill advised. Wood wants to move, speaker boxes don't, not a great combo. You can get away with edge joined boards for panels, small stuff, sometimes baffles. All the solid wood speakers I made just kind of tore themselves apart sadly.

Simple MDF box with a veneer and a few braces is probably more than adequate for being dampened, make one solid piece that that goes from top to bottom to the sides with holes in it for an super inert box. Hard to argue with the ease of construction there and cost, plus how easy it is to make veneer on mdf look really good.

 

[bmc0]

Using solid wood requires adequate provision for wood movement if you want the cabinet to last—you can't just glue all six sides together like you can with MDF or plywood. As @Ktacos said, veneering an MDF or plywood box is very likely a better idea.

 

[suttondesign]

yeah. i may try better walnut veneered ply and solid corners. the 1/8” veneerd stuff I bought before was just tissue-thin.

 

[bmc0]

i may try better walnut veneered ply

Most plywood has "tissue thin" decorative face veneers. If you want thicker veneer, your best bet is to just buy the veneer itself rather than veneered plywood.

 

[suttondesign]

yup. that is my plan after going to the lumber yard today. got some mdf to start, and veneer rolls there are $90.

 

[suttondesign]

Got MDF boxes made up, and walnut faces applied with enough overlap on each side to meet flush with the veneer. I ended up buying on Amazon the 3M peel-and-stick veneer, which I've used before and had good luck with. Turned out to be less expensive than buying a roll locally plus the adhesive. Applied a coat of varnish to the MDF to even out the pores before applying veneer this weekend.

 

[suttondesign]

Boxes done. One dang veneer-burn which will need the repair ward, but otherwise pretty good. Got the aluminum-faced rubbery stuff in, along with internal braces.

 

[Reddoc]

Boxes done. One dang veneer-burn which will need the repair ward, but otherwise pretty good. Got the aluminum-faced rubbery stuff in, along with internal braces.

Boxes look great - veneer is very pretty!

 

[suttondesign]

Pretty much done. Haven't tested them yet. Waiting on finish to cure. A couple of cosmetic flaws. No one would mistake them for high-end factory-made, but they certainly do look hand-made, which is not nothing.

 

[suttondesign]

Measurements of one speaker's drivers, measured separately, to check crossover. Seems like I've built the crossovers correctly. Not sure about the dip at 7-8khz. Need to follow up on that. Presume it's a diffraction effect of some kind?

 

[suttondesign]

All four drivers, measured separately.

 

[suttondesign]

Can someone explain the phase issue here?

 

[suttondesign]

Heissmann crossed over at 100hz to Linkwitz open-baffle bass drivers. EQ applied at 2500 hz to level out the broad dip from 1000-4000hz.

 

[suttondesign]

Have now built these and tweaked the setup using rew for some light correction for room issues. They sound very beautiful. I have big subs chime in at a 50hz low-pass.

These are not a super easy build, but a great value if you do. The crossovers are pretty complicated, but I used wago connectors, mui bueno.

I plan to get one speaker over to Amir to measure. My own final rew measurement is really good.

Now I have to decide how to keep these alongside my Linkwitz lx521.4. But it is proving easy to switch them out because I use speakons for everything and can select a stored set of parameters on the minidsp flex 8. cinchy.

 

[suttondesign]

Heissmann crossed over at 100hz to Linkwitz open-baffle bass drivers. EQ applied at 2500 hz to level out the broad dip from 1000-4000hz.

superseded by jettisoning the linkwitz bass module and tweaking in rew.