First self designed build: Input welcome

[jinjuku]

Looking at a WMTMW called the Infinydels

W: Infinity Kappa 100.9w
M: Zaph ZA1408
T: RS28F-4

MTM open baffle:
Tweeter would be LR4 at 1700Hz
Mids wired parallel for 4 Ohm

Woofers would be sealed and wired series for 4 Ohm. LR2 at 300Hz and a filter at ~30Hz. Thinking along the lines of 1.2 cubic feet. The Kappas have a higher power handling then some other 10's and after hearing the 12" version the SQ is solid on these.

Any input on other suggested x-over points or slopes is welcomed.

It would be an active setup with my DCX 2496 and of course 6 channels of amplification.

[johnnyrichards]

Sounds like an absolute blast to me Great drivers and a great concept, I would make only one change and that is driving the MTM crossover somewhat lower, maybe 1300 or so. IMHO, of course.

[jinjuku]

Sounds like an absolute blast to me Great drivers and a great concept, I would make only one change and that is driving the MTM crossover somewhat lower, maybe 1300 or so. IMHO, of course.

What is the power envelope on the Tweeter going to be at that point? I was hoping to use the ZA14W08s' clean frequency extension to take it a bit easier on the tweeter.

My plans are to sandwich the woofer section between two ply frames and allow for a baffle for the MTM to be independent in width. Also I want to have the woofer bins able to rotate on the X-Axis so I can not only toe in on the Y but angle the woofers in.

[johnnyrichards]

It didn't seem to have any problems filling an auditorium crossed at 1K down there in Iowa

It should still handle 10 or 15 watts crossed that low, and that will make it plenty loud I imagine.

[JasonP]

Looking here, http://www.zaphaudio.com/ZA14W08/ the distortion profile around 2k is much like the RS150-4 I used in my Bento Box. I use an LR4 at 1800 and even tried a 2000 at one point (but backed out because phase was an issue) and they seem fine to my ears. I'd think your 1700 LR4 is good, but may need damping on the cone breakup. If you design your XO in PCD and post here, you can get a lot of help on that

On the other hand, I'm not sure you need to "go easy" on the RS28F and it likely to blast away with an LR4 at 1500, though I have no hands-on experience with it.

Design looks good to me so far!

[killa]

Xo on the mid at 1700 should be fairly easy to do.

[djkest]

Looks like Zaph crossed his ZA1408W's over around 2.1k in his MTM speaker, and 1800 in his MT. LR4 slopes IIRC.

The "Contest Winner" Javier Huerta did lower, 1.6k with 4th order slopes, and that's an MT. We know the Dayton RS28 has been used as low as 1k so really you have a lot of flexability here.

[GranteedEV]

What is the inductance on these Infinity woofers?

Here's a woofer ya might wanna consider FWIW:

http://www.parts-express.com/pe/show...r=296-624&FTR=

[jinjuku]

What is the inductance on these Infinity woofers?

Here's a woofer ya might wanna consider FWIW:

http://www.parts-express.com/pe/show...r=296-624&FTR=

How much is inductance going to matter on an actively x-over'd setup?

The Kappa is a budget/SQ trade off.

[GranteedEV]

How much is inductance going to matter on an actively x-over'd setup?

For a 300hz crossover? Tough to say, but I'd imagine it's a decent source of distortion.

More importantly it could really reduce your sensitivity in the lower mids.

[Face]

A much better choice for a woofer: http://www.madisoundspeakerstore.com...5-6-10-woofer/

[Trap]

One nice thing about an active design is, of course, you can experiment with different xover points on the fly, live with it for awhile, change is you have to or want to without any expense. I had an RS28-F runnig actively for awhile in a TMM 2.5; ran it as low as 1000 LR4 at reasonable levels and never felt it was stressed.

[Pete Basel]

The Kappa 100.9w with a very low Vas and high Fs is not really optimal in any way for a sealed box system. I'd go with TC Epic's even a single 12" but then you might need a lower crossover point - perhaps use 4 Ms with a lower XO.
Even the Infinity 1262W, or 1062 if you must use 10s, are better choices as far as fitting a sealed alignment.

Have you run simulations? Do a pair of M's have enough VD for the crossover point you've chosen considering that it is OB and will need significant EQ?
You can do MaxSPL simulations for the tweeter taking into account the Xmax spec.