RS-P WWMTM 3 Way underway ( pic heavy )

[filmslayer]

The beginning started a couple months ago with me finding 2 pieces of 1" MDF already cut to 10.5" x 43" in the scrap pile at work and having a half gallon of Duratex left over from my first build and i wanted build an amp friendly 3way, this is what i came up with .

the drivers
http://www.parts-express.com/dayton-...4-ohm--295-377

http://www.parts-express.com/dayton-...4-ohm--295-371

http://www.parts-express.com/dayton-...eeter--275-140



i also bought a UMM-6 so these will be measured ...





After selecting the drivers i reached out to a couple people for help . Mr. Chris Reomer graciously double checked my box dimensions and that was a good thing as his numbers came out a little different than mine and the ones i used ... thank you Chris .
What we come up with was over all OD of 10.5"w x 43"h x 15.5"d using a 4" x 5" Precision Port located 18" down center line of back and gives us tuning around 40hz (these will be for music only) . the test box went together pretty quick ...



but after receiving the drivers i wasn't sure about the small RS125's and contemplated switching to the RS150p's ...so i made a test box for the MTM and and took measurements ....


MTM test box raw driver measurements 1/12 smoothing applied...

RS28




top 125




and bottom 125




got those sent off to the other person i reached out to , Jbruner ,so we can get an XO simmed ... pour Josh i'll bet that he really wishes he would have never posted in my first thread offering to help ... LOL :p


now that all brings us up till today . i really got after it this morning and cut the baffle... i was concerned with this . but got the spacing and rebating with no issues ..




the back-cut started with a small but deep round-over that i filed off the lip ...






and a small round-over for the 225's ...








dry fit on the box ...




i wasn't gonna start a build thread till they were done but was reminded that there is a lot to be learned from someone learning as they go and some may enjoy a different perspective . so here we go ...

[donradick]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

Totally awesome build!

[Mike220]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

Now this is my kind if tower! Nice build, keep us updated.

[jcandy]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

How interesting. Not to hijack, but this reminds me of an old project. The motivation was mostly to solidify the treatment of multiple drivers in some simulation software I was developing. They handle dangerously high SPL without flinching.

[LITTLEME60]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

Looks awesome, I love the configuration.

[filmslayer]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

no worries about hijacking i'm just having fun ! and thanks guys...

a few more details , box is 3/4" stuff, titebondII and brad nailed . seams caulked and sealed with liquid nails. MTM chamber is .33^3 . 225 chamber about 2.8^3

[jbruner]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

Here's a preliminary sim. I used the factory response curves and ran them through Response Modeler to add the baffle effects. If anyone wants to play along, I could post the files.

We'll use in-box measurements later and see how close this is. Ignore below 100hz.

The RS125P looked pretty wonky, but crossing low seems to work ok.

[jbruner]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

Or maybe a more relaxed version-

[filmslayer]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

Thanks Josh !

[jhollander]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

Nice build. Without seeing the circuit IMO it looks like you need to take a bit more baffle step out and damp the inductor peak on the RS225.

[RBG]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

I am not sure about mid-tweet cross over... No doubt RS28 can play low, but for me it sounds a bit thin that way. I would definitely cross around 2k5. You will have to work on that 125p dip though.

[jbruner]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

Nice build. Without seeing the circuit IMO it looks like you need to take a bit more baffle step out and damp the inductor peak on the RS225.

Very perceptive. The mids are not padded, so we're giving her all she's got, captain. We've already discussed the potential need to address the filter peaking, possibly with an LCR comp.

[jbruner]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

I am not sure about mid-tweet cross over... No doubt RS28 can play low, but for me it sounds a bit thin that way. I would definitely cross around 2k5. You will have to work on that 125p dip though.

The factory curves are pretty bad, but I'm thinking these look a little better, so after we get in-box measurements, maybe we can do better. I'd like to get the x-o closer to 2k.

[tyger23]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

Wow, I've been playing with the Rs-225 aluminum, Rs-100P, and rs28a.

It would be interesting to see these head to head ;).

[filmslayer]

Re: RS-P WWMTM 3 Way underway ( pic heavy )

rainy and slow at work gave me the time this morning to get the port and binding posts in ...






and it looks like i missed a good conversation while i slept ...