[stevecuss]

Hi Danny and Crew,

Danny, I called you a couple of days ago about a potential MTM project I was thinking of buying.  I went ahead and purchased everything and here is what I now have:

-- 3/4" MDF cabinets with routed holes for a MTM design.   dimensions:  17.5" tall by 14.5" deep by 8" wide.  Looks like they don't have removable baffle and they come with magnetic screens. 

-- a pair of morel tweeters.  the label is removed, but one online source identified them as mdt33s.  I have photos that I can send to get a second opinion, but probably I should get them measured locally to confirm that they are actually mdt33s.  Anyway, for now, I'll assume that they are morel mdt33s. 

-- a pair of audax aerogel hm130z0 5.25" mid woofers. 

I plan to keep the tweeters and sell the audax or use them for a different project later on. 

here are a couple of quick questions: 

Am I locked into an MTM design or could I explore a TM or even 3 way design here? (I don't plan to use a sub for some time.) 

can you recommend a design and components that would work with these morels?

my goal is to significantly beat the Boston CR77 bookshelf speakers I own and even beat the B&W CM1 speakers that I wish I could afford. 

my budget to complete this project  (woofers, crossover, back plate etc) is up to $400.

thanks for any help!

Steve

[Vapor Audio]

The Morel MDT33 is a great tweeter.  They're easy to work with, can handle a boatload of power, can cross low, and are very low distortion.  They can work with a 1st order electrical at the right xover point too.  I'd say some of Danny woofers would be a nice match, 1st order on woofer and tweeter would make for easy phase integration.  If you feel like being daring, the MDT33 works extremely well in a waveguide 

You could use the box for a 2.5 way, but I wouldn't consider that unless you use a woofer with a bit of a rising response.  With Dannys woofers you don't want or need to try a 2.5 way, you'll end up with a thick muddy lower midrange due to their natural response.  However that same natural response makes them easy and perfect for a MTM, you'll only need 1 or 2 db of baffle step. 

Those hm130zo woofers are pretty sweet  sounding though, nothing wrong with using them.  They don't give much bass, but for a sealed box MTM integrated with a sub I imagine they'd sound quite nice.

[Danny Richie]

I have to agree with Turbo. That is a really good soft dome tweeter.

Your box is just about right for a pair of our M-130/16 woofers to flank each side of that tweeter. Our woofers are pretty easy to work with too so your crossover will not be too complex. You can start with the woofer network used in our A/V-3. It uses a single inductor followed by a cap and resistor in shunt.

Getting that tweeter to match the roll off slope of the woofers should be pretty easy. We use a second order on our tweeter with a single resistor in line with it. The values would have to be adjusted a little but the same order network should work fine. On this one I could suggest some values that will get you pretty close.

You can check the cabinet plans at the bottom of the page for the A/V-3S to see what you'll need for hole sizes for the woofers.

[stevecuss]

Hi Danny and Turbo,

thanks for your response and advice!  I'm going to explore crossover design, come back and choose woofers, then go from there. I'm excited to see how it turns out

best wishes

Steve

[stevecuss]

Hi Danny,

Ok, so I've done quite a bit of research and then took a two week driving vacation and now I'm back in the game again. 

So I'm really intrigued by combining the morel tweeter with your drivers, but I'm clueless when it comes to crossover design.  Are you suggesting that I buy the crossovers in your kit and modify them/customize them for the morels? 

It looks to me like my cabinets are the same as your AV2 cabs.  (same dimensions in 3/4"mdf with a 2" port diameter in the rear.)  They have 4 3/4" driver holes and braces that look like shelves near each driver hole.  magnetic grills. 

So I assume your drivers would fit comfortably and I'd end up with an 8ohm mtm which would be nice.  I've also been exploring trying to squeeze larger drivers into the slots for lower bass response.  For example, the Dayton 6" drivers and the Seas CA15. 

anyway, if I go with the GR Research drivers, how would I modify the crossover?  I assume I would expect about the same bass response as your AV2 kit. 

thanks

Steve

[Danny Richie]

I guess I am in a really good mood today and I am feeling like helping you out. I'll send you a PM on this.

[Hank]

Danny, can you post a schedule of your future "really good mood" days? 

[stevecuss]

Hi Folks,

I called Danny and placed an order for 4 m130 drivers and needed parts to go with.  Imagine my surprise when they showed up on my doorstep less than 24 hours later.  Now THAT is fast service.

Time to wire them up and study the art of cabinet lining....

Steve