rabbitz,
I made a circle jig similar to this from 3 mm aluminium plate and probably more durable than that. Works really well when I get off my bum and use it.
I made a circle jig similar to this from 3 mm aluminium plate and probably more durable than that. Works really well when I get off my bum and use it.
It looks like an IED.
So I've got one cab to the point where I can make a noise with it. No crossover yet - I'm using the P13WH woofers as full-range drivers. I've loosely filled the lines with 150gsm polyester cushion stuffing down to the point where the labyrinth starts. No felt yet as it still hasn't arrived. I've left one side unglued so I can play with stuffing, but the baffle is glued in.
Anyway, it sounds awfully bloody good. I'm really surprised at the depth of bass from these titchy drivers. My garage is a terrible listening room, as it's quite big (6x6) and full of (dusty) junk, but this little speaker is really filling the room.
So I've got one cab to the point where I can make a noise with it. No crossover yet - I'm using the P13WH woofers as full-range drivers. I've loosely filled the lines with 150gsm polyester cushion stuffing down to the point where the labyrinth starts. No felt yet as it still hasn't arrived. I've left one side unglued so I can play with stuffing, but the baffle is glued in.
Anyway, it sounds awfully bloody good. I'm really surprised at the depth of bass from these titchy drivers. My garage is a terrible listening room, as it's quite big (6x6) and full of (dusty) junk, but this little speaker is really filling the room.
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This is brilliant work, suzyj! I am gripped! 😀
Ol' Lynn Olson is probably watching with interest too. His reputation is on the line. 😱
Ariel Speaker Page
I think a 5" MTM is an excellent idea. The Gryphon Mojo used two SEAS paper CA15RLY basses. A steen Duelund 4th order filter, I suppose. But people always seem to have a good time with the concept.
Could I embarrass myself by asking if you are a girl? I mean, this sort of stuff is a very male and aspergers syndrome province usually. But women who throw away their dollies and like a good power drill always get my admiration.
Ol' Lynn Olson is probably watching with interest too. His reputation is on the line. 😱
Ariel Speaker Page
I think a 5" MTM is an excellent idea. The Gryphon Mojo used two SEAS paper CA15RLY basses. A steen Duelund 4th order filter, I suppose. But people always seem to have a good time with the concept.
Could I embarrass myself by asking if you are a girl? I mean, this sort of stuff is a very male and aspergers syndrome province usually. But women who throw away their dollies and like a good power drill always get my admiration.
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Could I embarrass myself by asking if you are a girl? I mean, this sort of stuff is a very male and aspergers syndrome province usually. But women who throw away their dollies and like a good power drill always get my admiration.
Let me check...
Yup. Definitely a girl. Also definitely very into busting stereotypes. At work I build really big radiotelescopes. I used to design RFICs (for radiotelescopes), and before that I worked with lasers. For fun I build bicycle frames, play with motorcycles, design and build amplifiers and other audio toys, build boats, play with old computers, you name it. I also love cooking.
So yeah, just a typical girl. Fit all the stereotypes.
😀
Wow!!! Those look really good! Very elegant!
Construction hints: Air-seal is really important to quality and depth of bass. The amount of filling is up to you, but less is more in this application. A few strips of felt in the small chambers behind the drivers is all that is needed, and the amount of loose wool or cotton fibers in the transmission line is up to you.
The 3.8 kHz acoustic crossover means the 5.5" Vifa (or similar) drivers are nearly full-range. People are always surprised when I shut off the tweeters ... there's still a lot of sound there.
Since you build your own amplifiers, you'll have a lot of fun subjectively tuning the amplifiers; you will definitely hear small changes to the circuit and power supply. I've been very surprised that fully independent supplies for the final section, and the front end, has turned out to be so audible, although I don't know if the same finding would apply to the transistor world.
P.S. The Amity amplifier is named after my daughter, and the Karna is named after my best friend and life partner, Karna. I picked the name "Ariel" out of thin air, no explanation for that, and I haven't yet dreamed up a name for the new speaker, whenever I finally get around to building it.
P.P.S. Maybe I should take the hint from the quality of the Ariel's bass and attempt a transmission line for the Altec/GPA 416 or 515 drivers. It would be insanely large, I'm afraid, so maybe not.
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Ah, Lynn, one of my great sleeping loudspeaker heroes. When are you going to wake up?
Rogers Loudspeakers › LS5/9
mh-audio.nl - Home
Bit of work to do there, IMO. Get that impedance flat, and then it won't matter if you drive it with valves or semiconductors. All just electrons in the end. 😀
suzyj, it's a crazy world we inhabit. I'm all for your investigation of it. And I'd adopt you. 🙂
I always liked Sophie Germain. Let down famously by Gauss. Shame.
But my gift to you for some Sterling Work is the reason we all pursue this insane hobby: https://www.youtube.com/watch?v=R3ZyPGnxgyY
Gotta love that woman Kate Bush. Birdsong and Aussie accents included. 😀
Rogers Loudspeakers › LS5/9
mh-audio.nl - Home
Bit of work to do there, IMO. Get that impedance flat, and then it won't matter if you drive it with valves or semiconductors. All just electrons in the end. 😀
suzyj, it's a crazy world we inhabit. I'm all for your investigation of it. And I'd adopt you. 🙂
I always liked Sophie Germain. Let down famously by Gauss. Shame.
But my gift to you for some Sterling Work is the reason we all pursue this insane hobby: https://www.youtube.com/watch?v=R3ZyPGnxgyY
Gotta love that woman Kate Bush. Birdsong and Aussie accents included. 😀
I've been doing rather a lot of listening to my mono Ariel without tweeter over the last couple of days, mainly in an effort to run the drivers in before measuring things.
I was listening to Six Blade Knife, by Dire Straits this morning, and started to worry that something was wrong. Six Blade Knife has a very pronounced bass guitar riff, and it sounded really quite different to the normal speakers that I listen to, Infinity RS-5b's, which use 10" poly woofers in a sealed cabinet.
So I went back and forward A-B testing between the Infinities and the Ariel trying to identify what was "wrong" with the Ariel, wondering if perhaps there was some undamped cone movement, and it dawned on me - the difference is the Ariels have really fast transient response, so the bass guitar pluck comes through really well, with no mushiness. I'm hearing the dynamics of the bass cab that was used to record the track, which of course has very little damping, being a guitar speaker.
I confess I'm surprised at how different they sound - I'd always thought my Infinities were pretty accurate speakers.
I was listening to Six Blade Knife, by Dire Straits this morning, and started to worry that something was wrong. Six Blade Knife has a very pronounced bass guitar riff, and it sounded really quite different to the normal speakers that I listen to, Infinity RS-5b's, which use 10" poly woofers in a sealed cabinet.
So I went back and forward A-B testing between the Infinities and the Ariel trying to identify what was "wrong" with the Ariel, wondering if perhaps there was some undamped cone movement, and it dawned on me - the difference is the Ariels have really fast transient response, so the bass guitar pluck comes through really well, with no mushiness. I'm hearing the dynamics of the bass cab that was used to record the track, which of course has very little damping, being a guitar speaker.
I confess I'm surprised at how different they sound - I'd always thought my Infinities were pretty accurate speakers.
Not asleep, just doing other things. We've adopted a doggie (a 2-year-old Border Terrier) who is keeping us plenty busy right now. He's sleeping 3 feet away from where I'm typing this.
Kind of stuck on the LF part of the "Beyond", plus, in all honesty, I keep being surprised how good the Ariel + Karna amplifier sounds compared to the usual drek at the hifi shows.
There's something about the sound of direct-radiator closed-boxes that I'm not entirely happy with. They measure great, impulse response is good, but there's a subjective sense of "flatness" compared to TL's or horns, and I'm not sure why. I surmise they are some hidden parameters that makes systems sound different in a range where the drivers are be flat and distortion below perceptible limits. For that matter, the pro 15" drivers should sound identical in the very easy piston-band 200~800 Hz range, and plainly, they don't. They actually sound very different from each other, and I have no idea why. There's some rather weird things going on in this portion of the spectrum.
One crude guess is that box modes, although low in level and not that easy to measure (unless you put a probe in the box), are very audible and degrade the sense of "speed", quick changes in dynamics, and musical timbre.
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Amplifier heatsinks
A couple of photos showing progress on the heatsinks for the amps.
All the active circuitry gets mounted to the back of these heatsinks. Power transformer, a pair of latFET monoblocks, and active crossover. Then the circuitry is buried in dead space at the back of the speakers.
The heatsinks are built from schaeffner 1m long 150x27 extrusion (http://au.rs-online.com/web/p/heatsinks/1771804/). I've cut them to 400mm for now and milled a flat for mounting bolts and power/signal inputs at the bottom. I suspect I'll be cutting them a tad shorter before completing the top mounting flats.
They're reasonably unobtrusive, being fairly flat to the back of the speaker. I'll anodise them black once I've finished the milling, so they won't look quite as awful. Thanks to the length they'll be well under 0.5 degrees per watt, so should stay nice and cool despite the amplifiers burning plenty of bias current.
A couple of photos showing progress on the heatsinks for the amps.
All the active circuitry gets mounted to the back of these heatsinks. Power transformer, a pair of latFET monoblocks, and active crossover. Then the circuitry is buried in dead space at the back of the speakers.
The heatsinks are built from schaeffner 1m long 150x27 extrusion (http://au.rs-online.com/web/p/heatsinks/1771804/). I've cut them to 400mm for now and milled a flat for mounting bolts and power/signal inputs at the bottom. I suspect I'll be cutting them a tad shorter before completing the top mounting flats.
They're reasonably unobtrusive, being fairly flat to the back of the speaker. I'll anodise them black once I've finished the milling, so they won't look quite as awful. Thanks to the length they'll be well under 0.5 degrees per watt, so should stay nice and cool despite the amplifiers burning plenty of bias current.
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Just from Bunnings. Here in Geraldton WA it's pretty much the only decent Australian hardwood available, as Bunnings (the only game in town) no longer sells Tassie Oak.
Incidentally the bench behind the speaker is made from Tassie Oak (I bought lots when Bunnings were clearing it out) with a Jarrah top. That gives a good idea of the colour of the Jarrah after it's finished and aged for a while.
I'd have loved to do them in Tassie Blackwood, to match our dining suite and coffee table, but balked at the cost.
Incidentally the bench behind the speaker is made from Tassie Oak (I bought lots when Bunnings were clearing it out) with a Jarrah top. That gives a good idea of the colour of the Jarrah after it's finished and aged for a while.
I'd have loved to do them in Tassie Blackwood, to match our dining suite and coffee table, but balked at the cost.
Thanks.
As an ex-West Australian, I love jarrah; hard, tough and almost indestructible, as well as being beautiful.
As an ex-West Australian, I love jarrah; hard, tough and almost indestructible, as well as being beautiful.
A quick photo at the conclusion of this weekend's work.
I spent some time over the weekend putting a lid on the speaker. I started by trimming the baffle and sides to the right length, then made a jig for the router so I could put a 45 degree bevel on the inside of the baffle and sides at the top. To make it more accurate I took a cast of the top of the speaker using thickened epoxy to get the radius between the baffle and sides just right.
Once that was sorted, I made a top from Jarrah planks, routed a corresponding bevel into the sides and front, and worked the corner bits with a chisel to get the radius to match. It took much of the afternoon. I was happy once I couldn't get a fingernail in all the way round. Then I glued it in place after running some wiring for the drivers.
Finally this evening I've been French polishing it. I'm on to application five. After three I rubbed it back with 0000 steel wool. I've never done French polish on something of this scale, and am having some difficulty keeping my pad just right so it glides. Anyway, it's a work in progress and the cool thing about French polish is that if I stuff it up I just polish the mess back with fine steel wool and keep going.
I spent some time over the weekend putting a lid on the speaker. I started by trimming the baffle and sides to the right length, then made a jig for the router so I could put a 45 degree bevel on the inside of the baffle and sides at the top. To make it more accurate I took a cast of the top of the speaker using thickened epoxy to get the radius between the baffle and sides just right.
Once that was sorted, I made a top from Jarrah planks, routed a corresponding bevel into the sides and front, and worked the corner bits with a chisel to get the radius to match. It took much of the afternoon. I was happy once I couldn't get a fingernail in all the way round. Then I glued it in place after running some wiring for the drivers.
Finally this evening I've been French polishing it. I'm on to application five. After three I rubbed it back with 0000 steel wool. I've never done French polish on something of this scale, and am having some difficulty keeping my pad just right so it glides. Anyway, it's a work in progress and the cool thing about French polish is that if I stuff it up I just polish the mess back with fine steel wool and keep going.
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