Re: Mod 2 T build

[Bear]

Are you starting a project?

I was heading down the Duet10 route, but I just couldn't make the box geometry work with the space allowed by my HT desires and my Wife's tastes. At this point, I'm going to do a pair of Minuets from baltic birch in a translam style, so hopefully only the baffle will need veneer.

I used to build speakers back in my college days, but they were lucky to get paint.

[Clearwave]

Translam? Now that should look great. Who needs paint!

Ripcard, great looking build and make sure you give them 10hrs or so to break in. The W4s really start to open up after some time playing.

[Clearwave]

Kind of a bittersweet moment here. As I type, I'm listening to my first DIY speaker build. I don't think I'll ever buy another comercial speaker. DIY is simply too rewarding. It must be doubly so for the designer when he first hears his own design. I'm happy with the look and am amazed at the sound quality of my 2Ts. They have only been playing for a couple of hours now and they surpass anything I've ever heard. Jed, I can only imagine what your reference designs must sound like. I played around with placement in the shop a little and there is quite a difference in bass response depending on wall proximity although the bass response seems to have deepened on it's own as well with a few hours playing time. I just finished listening to Pink Floyd - Have a Cigar. Wow! I can't see needing a sub for music. The detail and clarity are also amazing. I'll continue to break them in for a couple of days with music before moving them into my home theater set up.

So here is the final build update.

After staining the cabinets and applying the first coat of poly to seal them, I glued the baffles on. By laying the speakers on their backs and using blocks in the driver cut outs I was able to apply quite a bit of clamping pressure without marking the finish in any way.

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I then hooked up and installed all the drivers using a thin closed cell foam self adhesive weatherstripping. I piloted all the crews with a 3/32" drill bit.

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I then masked the edges of the baffle and applied 4 more coats of the wipe on poly. I sanded in between with 320 grit except for the last coat. Unfortunately the tape didn't prevent some of the poly from bleeding through onto the edge of the baffle in places. So, now there is a bit of crinkle finish where it used to be beautiful high gloss. I'll likely respray the baffles when the weather gets better and I can do it outside, unless they buff out after I compound them. I don't think that is likely though. They'll have to do for now. I'm happy with the veneer finsih so it's just a matter of making sure when I do the baffles I don't ruin my veneer.

I then installed the binding post cups and ports. The heads of the screws for the speakers were too large to recess properly in the binding post cups so I found some smaller black screws in my parts bin and used them instead. The last step was to install the feet I bought to stabilize and dress up the cabinets.


Et voila.





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After hearing these 2Ts there is no doubt in my mind I'm going to complete the home theater with the Dynamic series. The surrounds will be next. I hope you enjoyed my build as much as I did.

Until next time, Rick.

Those are amazing looking speakers!!! I'm glad you are enjoying the Dynamic Series as much as I do.

[ripcard]

Thank you. I can't wait to start on the next project.

[Clearwave]

Thank you. I can't wait to start on the next project.

I'd recommend the 2cc since I'm not done with the 1S. I've been tuning the Minuet5 for weeks.

[ripcard]

Well, here's my dilema: I'm thinking the dimensions of the 4 CC would better suit my idea of placing my DLP on top of the centre channel in a new DIY low profile threaded rod style stand. I could just build the 4 CC or, the idea I've been toying with is to, build the 2 CC into the 4's dimensions with a cut down baffle like on my 2 Ts to show some cherry veneer from the front. I would shorten up the baffle to fit the driver grouping centred in the cabinet and allow the veneer to show on either end. I didn't want to add to your work load right now by asking for another custom/modified design and force myself to build the stand right away so I figured I would do the surrounds next. I know I've expressed my anxiousness to start, but in reality I can wait until you have had the time to perfect the design. It's not like I don't have a list of things to do here myself. I've been promising a new ceiling in the office and a bar in the rec room for a couple of months now. I'm just having too much fun with the speaker building.

[Clearwave]

There's no problem modding the 2CC like you mentioned, but the cabinet height should remain the same to keep the diffraction properties identical to the prototype cabinet's baffle proportions around the mids and tweeter.

[ripcard]

Yes, I figured the width would stay the same. I noticed the grouping of the tweeter and mids being tighter and assumed this is for the correct response when the speaker is lying down as opposed to standing. Both the 2 CC and 4 CC are 9" right? One inch wider than the towers. The length of the 4 CC would work best for my under TV/top of stand idea and the depth could be whatever works best for getting the volume closest to ideal.

[jjminch]

Those came out looking great. Can't wait to get mine. Where did you purchase those feet from?

[ripcard]

Thanks. Here is a link to the ad for the extender feet:

http://www.canuckaudiomart.com/details/110097-outrigger_extender_feet_for_floor_standing_speakers/

Good luck with your build, Rick.

[Clearwave]

Yes, I figured the width would stay the same. I noticed the grouping of the tweeter and mids being tighter and assumed this is for the correct response when the speaker is lying down as opposed to standing. Both the 2 CC and 4 CC are 9" right? One inch wider than the towers. The length of the 4 CC would work best for my under TV/top of stand idea and the depth could be whatever works best for getting the volume closest to ideal.

Yes, they are both 9". If you want, draw up a cabinet based on the 2CC, but extend the length to your needs. Keep the midrange chamber the same proportions. Keep the mids and tweeters in the same location. Keep the woofer in the same location relative to the mids. Then extend the cabinet length yet keep the total volume for the woofers the same as your 2T.

[ripcard]

Ok Jed, I've been playing around (mostly learning) with SketchUp and this is what I've come up with so far. This is the look I want and I think the dimensions will work out fine. This pic is a 2D version of the 3D model created in SketchUp because the picture hosting site doesn't like the 3D file format and you would need to open the file in SketchUp or AutoCad anyway, to get the full effect.

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No internal details in this rendering yet as I'm just learning my way around the program but it does give you the idea. I figured the dimensions to equal the volume of the of the original 2 CC but with a longer, shallower cabinet. Depth is reduced, but not so much that I can't still place the base of the DLP on top. The mid chamber stays the same but the space behind it will be reduced to 2 3/4" inches. Should still allow adequate air flow, I hope, with 2 3/4" x 7 1/2" openings in the braces. The driver spacing and arrangement remains identical to the 2 CC. Here is a hand drawn 2D layout of the interior.

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I assume 1 port the same size and length as specified in the original 2 CC? Let me know what you think.

EDIT: The original drawings I made have been removed and this is what I have come up with for my 2 CC build which will start soon in a new thread.

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[Clearwave]

That looks good to me. The only thing I might suggest is to have dual ports (one on each side like the 4CC), and separate the woofer sections into two with a solid partition wall in the middle of the area behind the midrange chamber, such that the woofer chambers are equally divided. The reason for that would be to eliminate any possibility of the narrow area behind the midrange chamber to act like a helmholtz resonator or disrupt the port tuning. We'd need to tune each woofer chamber to the same frequency. This will result in a different port length than the original single box layout given the volume difference of using dual woofers in a single chamber versus one woofer per enclosure. Then, completely stuff the area behind the midrange chamber.

[ripcard]

Hmm, how big does the area behind the mid chamber need to be before we can stop worrying about it acting like a resonator? I'd prefer to have a design that matches my towers in function as well as look. If it is just a matter of an inch or so more depth maybe I can shorten the length a little without drastically affecting the look I want. Or...what about just increasing the volume as opposed to keeping it the same as the 2 CC? Could that be tuned to work? Sorry for all the newbie questions.

[Clearwave]

With dual ports, the length would change but the tuning F3 would be identical. To not worry about that narrow passage way causing resonance issues, I'd line it with 3/4" Sonic Barrier and increase the dimension to 4".