Every time out they seem to be getting better.
We have just fired up what on early listening seems to be the best FR/WR design we've done yet. We call them the Bipolar-Bipoles. About 25 litres sealed, FR125 on one side, WR125+ApexJr T (1.8 uF cap on the other). Intended to give us both trials of a sealed bipole, and to compare the FR125 to the WR125 + simple super tweeter. With the terminals in the base, it is completely reversable cosmetically. At about a metre high, and 6" wide they are quite compact, and according to the lady of the house "cute". Intention is to build future ones with solid wood front & back.
Initial impressions --The WR125 side has more extended top & better dispersion but the FR side perhaps a bit better image stage. Really, really close thou & much more listening required. One thing that is notable is that the little single ended tube amps aren't choking on this one (limited on volume & the bass isn't as tight as with the PP or SS, but nicer in the mids at low volume). I have posted this design in the box design library.
No finish on them yet...
attachment is the base wherein hides the terminals....
dave
We have just fired up what on early listening seems to be the best FR/WR design we've done yet. We call them the Bipolar-Bipoles. About 25 litres sealed, FR125 on one side, WR125+ApexJr T (1.8 uF cap on the other). Intended to give us both trials of a sealed bipole, and to compare the FR125 to the WR125 + simple super tweeter. With the terminals in the base, it is completely reversable cosmetically. At about a metre high, and 6" wide they are quite compact, and according to the lady of the house "cute". Intention is to build future ones with solid wood front & back.
Initial impressions --The WR125 side has more extended top & better dispersion but the FR side perhaps a bit better image stage. Really, really close thou & much more listening required. One thing that is notable is that the little single ended tube amps aren't choking on this one (limited on volume & the bass isn't as tight as with the PP or SS, but nicer in the mids at low volume). I have posted this design in the box design library.
No finish on them yet...
attachment is the base wherein hides the terminals....
dave
Attachments
bipolars
can't he get some new plants?
sorry about the saw burn on the base filler, but I was in a hurry
While the EL84 SE amps have more transparent midrange and deeper soundstage, the PP EL34 definitely provides more bass "authority" and SPL. (that's shorthand for ballz)
Dave may massage the final dimensions on drawings, but don't even think about using MDF - these are Baltic Birch, baby: front/rear 17mm, sides & internal braces 12mm - all dadoed and glued only - the only screws are at the drivers and terminal cup/ base
oh yeah, the wife says:
"hey those are CUTE" (she's not at all crazy about the size of the bipole MLTL's, even with Macassar Ebony veneer)
can't he get some new plants?
sorry about the saw burn on the base filler, but I was in a hurry
While the EL84 SE amps have more transparent midrange and deeper soundstage, the PP EL34 definitely provides more bass "authority" and SPL. (that's shorthand for ballz)
Dave may massage the final dimensions on drawings, but don't even think about using MDF - these are Baltic Birch, baby: front/rear 17mm, sides & internal braces 12mm - all dadoed and glued only - the only screws are at the drivers and terminal cup/ base
oh yeah, the wife says:
"hey those are CUTE" (she's not at all crazy about the size of the bipole MLTL's, even with Macassar Ebony veneer)
Thats beautiful work.
I get my 125fr tommmorrow. Anyone want to build me an enclosure. Im really looking for maximum output out these babies. Im am running a resonant engineering RE 8 woofer for lower extension.
Which would you recommend the 7 litre bass reflex of the planet 10 minionken bass reflex or even a bipole for the fr's.
Location: MI
I get my 125fr tommmorrow. Anyone want to build me an enclosure. Im really looking for maximum output out these babies. Im am running a resonant engineering RE 8 woofer for lower extension.
Which would you recommend the 7 litre bass reflex of the planet 10 minionken bass reflex or even a bipole for the fr's.
Location: MI
kudisbetta said:
What type of enclosure are you looking for? You can see here I'm building Tom's PAWO Z-horn using 3/4" MDF layers cut with my CNC
http://fullrangedriver.com/forum/viewtopic.php?id=104&p=3
Thanks
soongsc said:
You can check Shopbottools for their current prices; as far as my router features,
- 4HP Brushless Columbo Automatic Tool Changer Spindle (3 tool holders) 240v Single Phase, 11 amps
- 49" x 97" Table Area (perfect for MDF)
- Vacuum table / channels for part hold-down / Aluminum T-Slot Table
- Closed Loop Servos / Ball Screws on all 3 Axis
- Repeatability .001", Resolution, .0002"
- beefy 1,500 pounds
Enough specs! The router was about $30,000, shipping about $2,000, ArtCAM Pro Software $7,500, Oneida-Air 2-stage Dust Collector, about $1,500 forklift rental...... (got myself into lots of trouble here)
I don't have any problems with cracking; dowels & Titebond glue on every layer holds plenty
Birch Plywood works very well; I use a 3/8" compression end-mill for a clean cut - MDF, birch ply, solid maple.... round corners, not a problem at all;
I can send you a sample or if you need something cut, just send me an e-mail,
Thanks
layertone said:
Layertone,
I think you really should have waited until the design was sorted. As is i can't recommend the design to anyone. I really do hope we can get it sorted because i don't know how we'd go about repurposing the bamboo ones, and it would be a shame to add them to the burn pile.
dave
My favorite speakers of the 1980s were British sealed cabinet designs by B&W and Celestion and Epos. The bass always seemed integrated, making smooth transitions into the midbass on up...till they got to the tweeter.
Besides a more spacious sound and more efficiency, what other benefits are there to a bipole.
One thing I wonder about with the bipolar bipole design that could give a third or fourth sound would be to electrically disconnect one of the drivers and use it as a passive radiator? Would this be feasible?
Besides a more spacious sound and more efficiency, what other benefits are there to a bipole.
One thing I wonder about with the bipolar bipole design that could give a third or fourth sound would be to electrically disconnect one of the drivers and use it as a passive radiator? Would this be feasible?
TomekZ said:
The biggest benefits are no bafflestep, and push-push loading of the driver -- active vibration cancelation which means better downward dynamic range & much less box load -- the shell of this box is 1/2".
A pretty expensive passive radiator. And since the PR should be a size up from the driver size and adjustable for mass, not a very effective one. (if anyone wants some 6 1/2" PRs i've got some)
dave
Scottmoose said:
They have a cupped, closed in midrange that makes them hard to listen to for very long. I suspected bounce off the back, but GM thinks the compression chamber is too small. We have a set of mules we can route out the back and add another piece over the back increasing CC size by about 20% without affecting the horn/transmission line. Given that we are sitting on an absoulutely gourgeous pair made of bamboo plywood, well worth a bit of effort to figure out.
dave
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