Last summer I built a pair of these. As far as I know I was the first and only builder of these so far. The 1st Maiko design was compromised for non-technical reasons and proved to be a disappointment after many hours of carving and assembling the parts. The new design is very optimized, and very different. It is smaller and has none of the problems of the 1st.
Bass seems to reach to about 50Hz, which is pretty good for 3.5" driver, the Feastrex D5nf, for which this speaker is specifically designed. The cabinet has a coupling chamber to catch the back wave, then through a large tuning port/vent and on into amplifying horns. Nicknamed BVR for big vent reflex, it is a great invention of Scott Lindgren (from UK) for single driver speakers to boost bass. Bass is low and clear. Many of the planet-10 speakers use this concept. Maiko 2 has angled sidewalls to reduce internal echo. But the rear wall of the horn is angled upward, giving a compound angle on those horn backs. A digital blade angle gage, free CADstd software and some creative layout and calculations helped me to determine the blade angle for the compound cut, which was listed incorrect on the plan. Early adopter hazard. hehe
I made it to plan except for 2 mods. Instead of internal bracing, I laminated another layer of 3/4" MDF onto the outer panels with greenglue, notched trowelled on in an even coating as Bryan suggested. This worked really well to reduce resonance in the side panels. I could hear the resonance decrease over a few days as the goo solidified. Next speakers I build I will use 1/2" MDF or plywood and use 2 layers of green glue instead of one. The other mod is experimental, I cut the front baffle into two unequal lengths, the short is glued on permanently, the longer one holds the driver and can be inverted to move the driver to the top of the baffle for improved imaging height, or move the driver to the center of the coupling chamber which is lower image height but that's how the bass system was optimized. It puts the driver equal distance from the vents, so the bass peaks will combine in phase to give clearer louder bass. I can always put a sub driver in a box under the speaker, to raise it up.
So far it sounds pretty good. After a couple months puttering with stuffing I started to hear the problems. Every diy speaker has problems to be worked out. For a while I was chasing a lower midbass resonance that no damping or stuffing could kill. I finally realized it was the unglued front baffle vibrating with the driver. I left it unglued so i could experiment with driver height. Plans wants it in the center which is pretty low. So I moved the driver as high as possible but this is supposed to compromise bass so I didn't glue it in, and the vibration of the baffle was severe, even tho it was wedged between the angled sidewalls. Today I made a support ledge up the inside edge where the baffle meets the sidewalls so the baffle will sit tight against th ledge and I will glue the lower permanent part into the speaker tomorrow. I am looking forward to hearing this thing play clear and low.
The Manley 300Bs are a good match to these drivers. The drivers are 91dB/w/m 14ohms so probably more like 93db. Then the horns will add some SPL too because some midrange does come out of the horns. Hopefully I'll have it tuned up and finished for the next g2g. It's only been 2 years since I bought these drivers! Time to fess up!
Been using zip wire to the screw terminals on the speaker, need to install some posts and solder the internal wire to the voice coil leads, then I can use the JPS on them and get liftoff. Tomorrow if all goes well.
Well the reason I posted on this and broke the silence after 6 months since building Maiko 2 is that I tried to do a tweek today when I was chopping the baffles in half. I wanted to stiffen the chopped edges that are floating in space vibrating freely. So I cut some roofing flashing aluminum (.020" thick) to precise shape of the ends of the boards. Sanded them rough, and used super West Systems epoxy to glue them on. 45 minute cure time came and went. The joints stil kinda sticky, WTF? 3 hours later I took it apart, the glue was still wet and the metal parts peeled right off. 4 hours wasted. That is the second time that exotic glue screwed me, so in the trash it went. I was frustrated and needed a place to vent. But by now I'm settled down. No need for pity. But thanks for reading anyway....
I'll put some pics up tomorrow after it get it back together. Then onto paint Ralph Lauren Sargent Green to match my fireplace mantle which these speakers will straddle.
Rich
Way to get busy Rich, sounds like a fun project. CAn't wait to hear them.
rob
cool... 8) Can't wait to hear them either..
If I understand right, could you use simple L-brackets in the corners to firm up the free floating baffles? You can even bend and twist them to conform to odd shapes. Not elegant but effective.
Looking forward to pics!
-C
Thanks for the idea and encouragement guys. Once I decide which I like better I will glue it all down tight.
Post pictures or it didn't happen. :-P
Oh, it happened alright....
(http://www.audionervosa.com/MGalleryItem.php?id=373)
New holes drilled for driver mounting and binding posts, internal wires made, binding posts reclaimed from chip amp project, but no paydirt today. Kids piano lessons and a nice long sunny walk around the frozen pond with wifey took priority. Tomorrow, I promise. As you can see, my wife is an audiophile's dream woman. Sitting happily among the wreckage.
Notice the two Feastrex drivers face down to the right. And the Maiko2s in the back left, FG guts showing. Baffles on the floor in foreground. Use your imagination to put them together. :)
:rofl:
all you need to complete the picture is a couple of kids working on homework amongst the disarray. Did you at least have some music on during this?
Just finished making a bigger mess in my audio room, so I enjoyed your photo all the more.
Need more pictures.
Rob
I had to make a bit of sawdust myself this weekend. I enlarged the holes in the back of my speakers so that I could run speaker cables direct from my monoblocks to the Fostex F200A drivers. It's ugly (like it was done by a complete amateur (yes it was), but rope caulk should take care of the now oversized holes.
Don't know about you guys, but it drives me nutty thinking about having nice/heavy speaker cabling in place just to leave the last little run to whatever wire the speaker builder used. Almost as bad, to have them use a cable that isn't anything like your chosen cable. Specially when you're running with a single driver anyway.
(In 2009 replaced zobel/baffle step circuitry with a modded Behringer DEQ2496 in part to provide the most direct connection between amp and drivers possible. This is supposed to help synergy between the two.)
Quote from: Rob S. on January 13, 2010, 09:11:04 PM
Did you at least have some music on during this?
Of course!! Pandora the Bebop/Combo shared station.
Quote from: JLM on January 14, 2010, 03:38:36 AM
Don't know about you guys, but it drives me nutty thinking about having nice/heavy speaker cabling in place just to leave the last little run to whatever wire the speaker builder used.
It is usually pretty surprising to see what's inside a commercial speaker. They figure it's good enough, you can't see it, and you don't know the difference anyway, so save a 1000 in costs and use the crap parts. My legacys had nylon disconnects you see in a car wiring harness on the crossovers. Made it very easy to remove, but not ideal for signal transmission. OtOH, good enough is good enough. They sure made nice music.
I'm using same brand wire inside and out, but I only have Dayton posts. Good enough for now.
Rich, need some updated pictures on the speakers, seems like you were 99% done. Got them fired up yet?
Craving an update.... :)
Yes they are finished, sorry for slacking off on the updates. The Ushers are gone so these are taking over for the next week or two anyway. I'll put up some pics later after gokarting.
I'm gonna have to rebuild them in Baltic Birch or White pine. The MDF that I'm using now dulls transients and smears things due to wideband vibration. The real woods vibrate but higher Q. I really want to make the next cabinet from aluminum plate, damped with wood or bed liner goo, etc.
I'm building some current source amplifiers for them, designed by Sol Samet. That makes a HUGE difference on single driver speakers, a whole new beast. That should be ready in a week or so.
Busy as a Bee. How cool is that building ones own speaker and amp. :thumb:
charles
Rich:
I know you are having fun with this project and cannot wait to hear your comments about the sound when you are finished.
Ken
Absolutely looking forward to it. Now where's that munching popcorn emoticon when you need it...
Bryan
:pop
Quote from: bpape on January 24, 2010, 10:21:34 AM
Now where's that munching popcorn emoticon when you need it...
You guys are too much! :D Since you're all settled in for a show, with popcorn and all, I gotta come through for my homeboys... so here's some pictures I took tonight after gluing on the baffles. It tightened up the MDF ringing and smear a lot.
(http://www.audionervosa.com/MGalleryItem.php?id=399)
(http://www.audionervosa.com/MGalleryItem.php?id=398)
(http://www.audionervosa.com/MGalleryItem.php?id=397)
(http://www.audionervosa.com/MGalleryItem.php?id=395)
And one during building, before horn angles or coupling chamber. The little boards form the ports with the back wall.
(http://www.audionervosa.com/MGalleryItem.php?id=396)
And finally, just to make sure you go home from the show satisfied, because I know this is not good speaker porn....
While waiting for glue to dry, I spent too much time at Rick Craig's new website tonight, selahaudio.com. Got a nice dose of humility to cool down my speaker building fantasies.
(http://www.selahaudio.com/sitebuildercontent/sitebuilderpictures/juliettarearview.jpg)
Plenty of good speaker porn there Rich. Looks like you're having way too much fun. Wait till you start playing with different phase plugs, damping on the whizzer, etc. Ask Scott F about that...
Bryan
Rich:
They look great!
Ken
What the heck is that.....that little tiny white speaker....in that big box ? [-X
What are you nuts Rich ???? :duh
Just having a little fun.... :rofl:
.........good work. 8) :thumb:
I heard those new one of a kind Selah's when rick delivered them to a guy in NYC. Unfortunately they were only broken in for about 5 hours, so I really can't judge what they sound like, but the build quality was pretty amazing.
Good luck with yours.
I wanted to host a G2G at my house to feature Rick's exotic OBs before their journey North, but it didn't come together.
Today I swapped in a pair of JPS Ultraconductor2 ICs on loan from Carlman (thanks Carl!) in place of the bluejeanscable.com Belden 1505 coaxial ICs that I had been using on these speakers. SHEBANG! We have bass! Overall big step up. Fatter tone, richer overtones, lower and louder bass, more open and powerful dynamics, and clearer transient details, and I can listen deeper into the background.
Spinning some Lee Morgan on vinyl now, this is getting really good. It is so easy to relax into a single driver speaker. It is so natural and graceful. None of the fatigue and stuffiness from a passive crossover. But also not the power handling or linearity of a multiway either, but good enough to enjoy most of my music.
Still using the i60, it is really wonderful, clean, pure, just not there. I will switch back to tubes tonight.
I'm ready to build another copy of this speaker, because there are some panels that are not damped and I can hear the God awful MDF ringing sound. If I do the greenglue thing like I did on the sides it will change critical thicknesses and screw up the bass alignment which is very sensitive. So I'm wondering what material to build them with next, this will be the 4th version. :-({|=
Choices I'm considering are Baltic birch, 2, 3 or even 4 layers with green glue between each. I can get 5.2mm russian baltic birch here in Raleigh, three layers would make .75" material thickness called for in the plan, so the tricky panels will be dead too which they aren't now. I could also use two layers of thicker BB, making the walls thicker than .75" and lowering resonance a little, and reduce the number of green glue layers to 1. I think that's going in the wrong direction.
Another material I am considering is hardboard. aka Masonite, Eukaboard, pegboard (without the holes). It is very dense and heavy, cheap, and 4x8' which is much easier to transport than the 5x5 sheets of russian bb. The 1/8" thickness allows me 5 or 6 layers with a green glue layer between each. With a roto zip I should be able to wall paper the layers on and trim the edges, making a labyrinth edge.
Green glue FAQ suggests that denser substrates are better than light. They also suggest that more layers of green glue are helpful. Butthicker layers nbeyond nominal .5mm thickness add nothing. This makes sense since the greenglue damps vibration by converting sheering force to heat. There is more sheering force if the layer of goo is thin than if it were thicker. The technique (thanks Bryan!) of layering it on with notched trowel seems to yield a final layer about that thickness.
I was thinking of making it in white pine, for the magic resonance of wood, but I think I am over that for now. I just want to hear the driver and the port, nothing else.
The thing that I don't understand in this puzzle is the effect of stiffness of the substrate. That should attenuate vibration amplitude, and raise the frequency which makes damping easier. Am I right? If that's true, then the birch plywood should be best?
On that note of stiffer is better (twss) What about Aluminum? I have heard that it is possible to cut aluminum with a table saw, and they have special blades for aluminum. Should I try 1/4" aluminum and damp it with internal slabs of BB and green glue, or maybe spray the inside with auto body damping goo like bed liner.
All opinions are welcome, except for "you're fucking crazy." That should be obvious to everyone by now.
Rich:
You must be having a lot of fun learning to be a master speaker builder. :thumb:
When you finally have a model you like I want to hear them.
Ken
Rich,
Not sure who it was, maybe Bob Brines, laminated HardiBacker concrete board (no green glue) right to the wood. Perhaps just for mass loading. I once saw a large floorstander that had the stuff applied in rectangular strips inside. The knuckle wrap test was interesting, not flexy like a Harbeth, not dead like an Eggleston sort of thing. Just different. No idea what it sounded like as I never got to hear it actually playing.
Tom