Ochocinco TM! - Take 2

[---k---]

I originally posted this at HTGuide, but thought that people here might enjoy seeing it.

I was asked by my wife to build a pair of speakers for a small living room. The criteria was: "smaller", reasonably priced, and able to take abuse from a variety of people. I also wanted something that could be expanded to a full 5.1 surround system if desired down the road. The plan is to build a small Dayton RS sub to pair with these.

There are lots of designs out there, but I'm still a little smitten with the Ochocinco's that I built for my brother last year. The seemed to fit all of my criteria also. For the size of room they are going into and for the usage I expect them to receive, the TM's seemed like they would be a better fit than the MTM. I debated a long time how to build them, but I ended up with a short tower. This seemed to solve having to build stands and will be more stable.

I also wanted to expand my skills a little and try something different. This is a small .5cuft sealed design in a short tower. There is a solid partition just below the midwoofer. Crossovers will store in the bottom. The box is built from 3/4" maple veneered plywood with a solid maple baffle. All the joints are mitered to conceal the plywood endgrain. There is NO veneer on this. The baffle width got reduced 1/4" (or so) because I used a 1x8 solid maple, which is actually 7 1/4" wide vs. 7 1/2" from the PE box. My miter joints sucked but are all backed up with wood blocking. Amazingly, with a little bit of wood filler, running the screw driver over the edge, and staining and the open joints disappeared.

Finishing was three coats of a General Finishes Gel Stain, which is a combo stain and poly. It has a nice protected finish that looks like real wood without the gloss of poly.











After getting them assembled for the first time, I did some listening. Ewe, ouch. Something wasn't right. After double checking my crossover a few dozen times, I thought I might be crazy so I contacted CJD. We arranged to meet up and do some listening.

I think CJD listened for about 30 seconds and was able to tell something wasn't right. He agreed they were a little bright and harsh sounding. CJD got out his measurement rig. I don't have his measurements, but he did some digging and here is what we found:

Original data sheet from Parts Express:



Data Sheet for "Rev 1" from Vifa / Tymphany's website.



The original tweeters used for the design measured flat and similar to the first response above. The tweeters purchased from PE around November 2011 measured very similar to the response posted on Typhany's website labeled as Rev 1.

After getting the new measurement, CJD imported it into PCD and had a new crossover what seemed like another 30 seconds. Two resistors needed changing. And luckily I've acquired a box full of various resistors over the years, and even more impressive I had the a pair of the two that CJD was requesting. Swapped those resistors in and MUCH MUCH better.

Cross over mod:



We listened for a while and CJD was satisfied. We synced his living room squeeze box feeding the monster 3-ways and his family room squeeze box feeding the TM. I was then able to run back and forth from room to room to compare the designs. At times I was wanting to take the tweeter down a hair and CJD was thinking the tweeter needed to go up a hair. So, I think it is probably about right.


In all, these came out way nicer than I expected. I've very happy with how they turned out. The flash and my photo skills don't do them justice.

[Steve Henry]

Very nice!

[patrickm]

They look great. What wood filler? Anytime I've done that the fill turns out really obvious, so I'm interested in how you managed that.

[---k---]

They look great. What wood filler? Anytime I've done that the fill turns out really obvious, so I'm interested in how you managed that.

Thanks!

It was just some Minwax Stainable Wood Putty. I'm a little surprised it work as well as it did. I wish i had some before pictures. My joints had an 1/8" gap in places. It isnt perfect, but looks darn good compared to what i started with and for not putting much effort into. I think it could be an optical illusion and the stain along the edges isnt so noticable. I dont know.

[duanebro]

Very nice! I like how you got that look without much work!