| 4Pi build [message #81406] |
Fri, 19 June 2015 13:50  |
pizzacat666
Messages: 9
Registered: May 2015
Location: Seattle
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Esquire |
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Hi Wayne, may I please have the plans for the 4 pi speakers?
I figured out where I am moving to, and the 2pi towers are just way too big for my small apartment. Depending on the cost of building the cabinets, I may choose to upgrade the drivers to the JBLs.
Thank you in advance!
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| Re: 4Pi build [message #81557 is a reply to message #81406] |
Wed, 26 August 2015 13:00  |
pizzacat666
Messages: 9
Registered: May 2015
Location: Seattle
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Esquire |
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I finished the construction of my 4 pi speakers last week and wanted to post a photo. They're not finished yet, and I haven't decided if I want to paint or veneer, but here is a picture of the speakers with the maker. I brought them to a friend's house and we demo'd them with a bunch of vinyl this weekend. We were able to crank them to the point where highs were shrill and started to hurt our ears. At that point, we backed the volume down a little. The bass was superb. Running through just a cheesy Sony surround sound receiver in 2 channel mode, the 4 pis filled the basement with punchy, crisp bass. I suspect the shrill highs were a combination of the basement we were in and the cheesy surround sound amp. I will be testing the 4 pis out more and providing my experience, but so far they blow away everything. I went to the theater to see a movie after the demo session with the 4 pis, and the experience in the theater didn't come anywhere close to the sound of these 4 pis. The 4 pis are clear and crisp like my headphones, but unlike headphones or the sound system at the theater, they rock the whole room you are in and make you the feel the music in your body. Pretty awesome!
I had a lot of fun making them too. The 3/4" MDF was only $65 at my local lumber yard for a 4x10'. I was able to get it home in a toyota camry by cutting it roughly in half, lengthwise, and folding down my back seats. It stuck out the trunk, but we just strapped it down to my hitch-mounted bicycle rack! It was too perfect.
I made a good cut plan, but I still needed to buy another sheet of MDF in 2'x4' because I was doing double front baffles. I cut the large pieces down using a table saw and the help of a friend.
Once the pieces were cut, we found it difficult to assemble them into boxes before the titebond III wood glue dried because it was a hot day. I don't have any clamps, but luckily we did have a pneumatic nail gun to nail the pieces together while the glue set. I left the baffles off during this step. Ultimately, I screwed and glued the cabinets together, but found the screws completely unnecessary. I figured people will probably try to sit on the cabinets at some point and want them to be strong enough for that, but just wood glue is enough.
To cut the holes for the drivers, I used a cheap rotozip style edge trimmer, a drill, and a handsaw. It actually went pretty well! First I traced rough holes with a pencil and used the drill to make holes that I could get my handsaw into and sawed the rough holes out. Once the drivers arrived in the mail, I was able to trace around them for my exact holes. I made a circle cutting jig out of a scrap piece of MDF. I think the circles came out pretty good. Then for the waveguide hole, I clamped a piece of scrap MDF on the baffles to use as a fence. I routed the rounded corners out free hand as well as one side of the hole that was too close to the edge to use a fence. Where I made mistakes, I simply applied wood filler and sanded it to perfection.
I used double-front baffles to get the drivers to flush mount. I found that just cutting a hole completely through the front 3/4" piece was good enough to get the woofer flush mount. Honestly, I wasn't going to spend hours routing the hole just so I could have 1/8" material left to make the driver perfectly flush. If I cared, I could use a double gasket to make up the difference. For the wave guide, I found it easy to set my router to the perfect depth and route out the small amount of material needed to get that perfect flush mounting.
For the port hole, I made a rough cut out with the handsaw, and then once the port was assembled in place, I routed the full cutout with a flush-cutting router bit. It worked flawlessly and gave a nice rounded look to the corners. Also, before assembly, I painted inside pieces of the port flat black latex using a sponge roller. I primed it with oil based primer first, because I read that MDF tends to swell up when latex paint touches it.
I used 2x2" scrap doug fir to brace the boxes. I know its not exactly a "hardwood" but I think it's more than strong enough considering it's in compression. It also smelled good when I was sawing it.
Once the cabinets were finished, I lined all inside edges with wood glue to ensure an air-tight seal. I read that silicone and some sealers can off-gas a harmful substance for your drivers, so I avoided them.
For the driver gaskets, I cut out pieces of pvc shower pan liner but found it was difficult to utilize for the woofers. My hole punch could not get through the material to make holes for the mounting hardware. So I ended up using the rubber o rings that came with the woofers, and they work just fine. The drivers have a recess on the back of the baskets where this o ring sits.
I also used the tee nuts that came with the woofers after a disaster with some over kill-sized nuts and bolts I bought from parts express. I found with the 1/4" tee nuts that my holes and placement had to be too exact otherwise the bolts would be going in crooked and either cross-thread or make the tee nuts spin. I found it difficult to get the tee nuts to press in perfectly straight using just a c clamp. I ended up using the smaller hardware that came with the woofers because it gave me some margin of error. They work just fine as well.
I wanted to build my cabinets while waiting for the kits to arrive, and it would have been nice to know more specifics of what Wayne's kit does and does not include. For example, I bought extra tee nuts and bolts plus extra shower pan liner for gaskets that I didn't even need because the woofers come with that stuff. On the other hand, the kits do not include any kind of mounting screws or hardware to use with the crossover PCBs and the rear panel connectors. So its a good thing I had wood extra screws. No one likes running to the hardware store when you are in the middle of a relaxing project!
The waveguide does not include a gasket nor mounting hardware. So you will need shower pan liner and tee nuts/bolts for that. I found the 10/32 size bolts worked well for the waveguide. The tweeter, however, does include the hardware needed to mount it to the waveguide.
I hate MDF and would not use it again. The dust gets absolutely everywhere including your eyes and throat. Plus it's really not very strong in the corners which leads to all your corners getting dented and rounded off during construction and moving the speakers. I would use baltic birch plywood next time.
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