Anyone care for an insane mix check speaker?

[chrisj]

Well- not really insane, but visually scandalous and surprisingly sonically good. Sort of like a lava lamp except for it's a mix check. I'd better just tell the story...

I was starting to experiment with small speakers with the intent of making a mix check speaker much like a clock radio. Tiny 3" alnico paper drivers. Not to get too colorful in recounting the story, let's just say I made enclosures that look like some kind of jet engine on a vertical pillar.

It's got two little speakers right next to each other producing both a teeny-speaker check and a mono check- but the enclosure from the speakers are simply tubes extending straight backwards and intersecting each other. They come to a point at the back. There's a bit of damping in there- nothing more than bits of bubble wrap which is extremely effective in tube-shaped enclosures.

Here's the trick (apart from the pseudo-mono bit). This equates to exactly the same thing as a mini B&W Nautilus enclosure, unrolled, combined with a vertical pillar that serves as a sort of pressure tank to expand the volume of the enclosure.

These little guys sound ridiculously good in certain ways, and are ridiculously fun to listen to. You can hear the kick quite plainly, and even heavily filtered bass, a bit, even when it's extremely low. I do a little trick with the dustcap to form it into more of an inverted dome, and the highs are very pleasant sounding for this type of driver (alnico magnets help). But it's mostly the bizarre, jet-engine-like enclosure that's doing everything, that back-chamber-tapering-to-a-point. The sucker is extremely revealing of anything from midbass to midtreble and it sounds totally unlike a clock radio, it gets size and depth and resonance seriously right.

I have to build some basic tooling for slicing the tubes along planes and cutting accurate intersections of multi-cylinder shapes, to do 'em properly, and then I'll have everything in place to make the ultimate 'what the FUCK is that' mix ref speaker, for pretty ridiculously cheaply if I can make the cylinders in some kind of jig instead of dinking around cutting them by hand (huge pain to make them fit right that way).

Anybody want some? (or more like, anyone want to hear more about these crazy things?)

[bbkong]

You're fucking crazy.



Not a bad kind of crazy, but just the same..

It also takes one to know one.

I'm working on a design to put a Harley motor into a Volkswagon dune buggy.

That kind of crazy.

I'll take a pair. hehe

[blackieC]

Waving fresh meat around before a group of hungry lions is a dangerous proposition.

My only advice after you have dangled the meat is to throw it to the lions as fast as you can and exit the pen until they have had thier fill.

When the beasts are sated and languid with thier bellys full, then you may venture back in with your brave tales of slaying the days kill that has given them the strength for the next days hunt.

So tell us, great hunter, how you have conquered and provided for the pride before the antelope turns and becomes so much carrion for the lingering Auratone vultures?



Hmmm?

[Tim Halligan]

Waving fresh meat around before a group of hungry lions is a dangerous proposition.

My only advice after you have dangled the meat is to throw it to the lions as fast as you can and exit the pen until they have had thier fill.

When the beasts are sated and languid with thier bellys full, then you may venture back in with your brave tales of slaying the days kill that has given them the strength for the next days hunt.

So tell us, great hunter, how you have conquered and provided for the pride before the antelope turns and becomes so much carrion for the lingering Auratone vultures?



Hmmm?



Somebody has seen a few too many nature doco's I think.

:lol:


Cheers,
Tim

[blackieC]

Well I do hold Sir David Attenborough in very high esteem, but I was speaking in metaphor in my previous post.


To put it in plain seppo speak, "Give up the info, bitch."

[Goes211]

To put it in plain seppo speak, "Give up the info, bitch."

:lol: :lol: :lol:

Bring it on, Chris.
Blackie has got the audience listening.

[Brendo]

Photos?

[studjo]

werd

[otek]

Yeah, pics would be great.

From your description it sounds like some kind of take on a Distributed Port (DP) design.

[Brendo]

/O/
/ /
/ /
\ \
\ \
\O\

I was picturing something more like this...

[otek]

/O/
/ /
/ /
\ \
\ \
\O\

I was picturing something more like this...


Er.... more like that than what? :Confused:

[chrisj]

Yay DV cam and screenshot- here's a pic of the thing. Remember it's a stereo speaker, that's the L and R you're seeing, ya don't need two. Also if I can make tooling it will be silly cheep.

Scary huh?

http://womb.mixerman.net/attachment.php?attachmentid=450&stc=1&d=1164741285

[rockdart]

You're just using cardboard tubes? How does the prototype work with PVC (thinking strength and longevity here)?

[chrisj]

I didn't make it with PVC. if you are worried about longevity I could sell them in six-packs :)

I made a recording. It is over a horrible little camcorder (got the video of it too but it's 536M unedited). This should be amusing. Don't laugh too hard or I'll suggest that you park a camcorder in front of YOUR studio mains and see how impressive the sound is that way... anyhow, we have a brief clip of the source (Team Galactic, original unmastered mix), then my mains making the camcorder unhappy, then switching off the mains and turning up the tinyspeakers, first at about 9" and then moving in to maybe 5" and then back a couple feet.

I haven't got anything better at the moment but this gives the idea of the voicing of the little fuckers. Too bad about the camcorder internal mics- it was the quickest way and it's amusing and here you go, now you're hearing them.

:D

[FajitaTone]

WOW.


That's pretty fuckin' cool!

:Coolio:

:Thumbsup:

[jimmyjazz]

http://www.scifimoviepage.com/images/et.jpg

[magicchord]

I think you've kinda sorta made a transmission-line enclosure. Is that vertical tube open or closed on the bottom?

[Brendo]

Yay DV cam and screenshot- here's a pic of the thing. Remember it's a stereo speaker, that's the L and R you're seeing, ya don't need two. Also if I can make tooling it will be silly cheep.

Scary huh?

http://newsimg.bbc.co.uk/media/images/40853000/jpg/_40853282_et_203.jpg

Scary indeed.

[studjo]

that thing looks friggin cool

let me know when you sell it :)

[Brendo]

I didn't make it with PVC. if you are worried about longevity I could sell them in six-packs :)

But have you tried PVC yet? Also, speaker grilles of some sort? If it works well, and is rugged-as-fuck, you could sell them as a portable monitoring solution. Is the "neck" connected into the other tubes or just tacked on the outside as a stand? If it's the latter, put in a 5/8" stand thread instead - this one's relatively easy to do, get a 3/8" to 5/8" thread adapter, and a 3/8" bolt on the inside, hold it all together with loctite.

[chrisj]

Hah! Brendo nailed it- E.T. check miiiix :lol:

Guys, I'm not sure you're getting it- I'm not f**kin JBL ya know? I have made PVC pipe speakers before- those ones were transmission line, these are mostly not- the vertical pillar is open to the top enclosure but the bottom is sealed, and the top enclosure doesn't work like a transmission line because it is tapered and sealed on the end. Transmission line = pokey and sluggish, tapered to a point = lively as hell.

If anybody has a line on cheap-ass injection molding or something, then I might as well talk PVC/plastic, but part of the beauty of these guys is that with a bit of luck I can make 'em in my basement and the cardboard walls do NOT hurt the sound compared to PVC. PVC is harder and all colorations move up in frequency to where they're more obnoxious...

Since it's not a transmission line what I'm now wondering about is what it would be like to make an even longer tapered cone with just one driver in it. I have 5 or 6 feet back to the corners of my room... if I can find some industrial process that produces cones (even cardboard) 6 foot long and anything from 3 to 8 inches on the wide end, it's time for more evil experiments. I am _seriously_ liking the liveliness effect of having the column of air behind the speaker be essentially horn-loaded.

I'm also dubious about the idea of grilles, location-recording-toughening etc... wouldn't you want REAL speakers for location? These are crazy toys with unusual sound characteristics, and even more unusual build qualities- I mean, if the drivers are a buck each, and the cylinders are about a buck, and the cable that plugs into a headphone jack is a few bucks or less, why would I want to be machining PVC and putting on frickin binding posts?

Maybe what I'm hearing is 'hey, you should make REAL speakers of this design' which would be fine and interesting. The thing I was thinking about was more along the lines of 'want a mix check device with mono/midrange emphasis for less than fifty bucks? How much less?' so I'm more thinking about whether I can cut the cylinders and simply glue them together and put the result in a box to send to someone?

If I did one that was nothing more than tapering to a point, I could ship them in larger cardboard mailing tubes, not even a box...

Are we _really_ looking for serious main speakers out of this stuff, enough to justify higher cost even though the thing would still be a one-driver? if I can whip the single-long-cone issue I could toss binding posts on and pick bigger drivers that would handle a tiny bit more wattage. These run off a headphone output.

[Brendo]

Well, how fucked up do they sound? I haven't listened to your camcorder thing yet, and I don't really trust a camcorder anyway..

I was thinking PVC would still end up being cheap, but if you think it won't sound as good, then that idea's out. I was just thinking in terms of sturdiness - cardboard is hardly known as the most reliable material for making anything.

[rockdart]

OK... but now you need to add wax paper of varying tensions that will kazoo at certain frequencies INSIDE the tubes...

just kidding

maybe

[chrisj]

They don't sound fucked up at all, that's the thing. Cardboard has very high self-damping and most of the shapes are cylinders, which are ideal pressure containment shapes- no wall vibrations, so the material doesn't matter. The tail end of the speaker isn't cylindrical but it's constrained by the edge- a small amount of energy can leak out that way but it seems to just help damp the internal resonances without putting much energy out.

If the camcorder thing is a serious problem I can try the same thing over again with a Studio Projects C1 or C4 and an API pre. Not sure how necessary this is, because I've never heard of anyone miking a speaker for critique anyhow- but why not?

Tonight I'm grovelling all over the net trying to find out if anyone ever makes long skinny cardboard cones. Technically I could create a form and then make them myself using anything from paper to fibreglass or carbon fiber (if I wanted to be posh, definitely some sort of posh fibre and resin arrangement- but the fumes will kill you surprisingly quick) but I can't help looking for a less labor-intensive answer.

If I do a long skinny ski-pole version, with a copper pipe down the middle glued onto the alnico magnet, the mass of the pipe will brace the voice coil assembly of the driver, and I can cut holes in the end of the tube so that once waves reach the end of the cone, the air can leak into another air resevoir that would actually be more of a transmission line, being a long empty tube. This would also provide a backbone to the speaker. I figure if the volume of the cone ends up similar to the volume of an optimal rectangular box, it'll be a suitable size. Logically if the cone is infinitely long it's no different than having a long tube, and that is like transmission line loading which I've tried and disliked :)

[chrisj]

Rockdart- actually that is the method of energy dispersal used by the bubble wrap :lol:

It's not a fibrous mass, so the air column within isn't impeded the way it would be by fibreglass- but sound vibrations force the plastic film to move against its support. You glue it lightly to the wall by a mist of spray glue like Super 77, and then any air fluctuation forces the bubbles to be compressed or stretched. Since they are plastic films, they don't actually stretch, they wrinkle and crumple. The motion of the folded plastic films burns up energy thermally.

I'm sure if you turned up the speakers loud enough, the whole internal bubblewrap damping layer would 'kazoo' for you in the 0.00001 second before the driver fried :D

[Brendo]

http://cgi.ebay.com/7-Paper-Mache-Cones-Lot-of-6-Cardboard-Cone_W0QQitemZ260055000881QQcmdZViewItem

http://item.express.ebay.com/ws/eBayISAPI.dll?ExpressItem&item=110010762082&FROM_MERCHANDISING=1&tr=merch:cvi

http://www.google.com/search?q=%22craft%20cone%22

EDIT: Oh wait, i just saw your length requirement!

[chrisj]

It only has to be three times the length of a cylinder with the same volume of a rectangular enclosure that would get halfdecent bass for the driver :)

However, that's still pretty tricky. Not even jumbo 3*30 degree industrial yarn cones quite manage it- they get up to about 11 inches and you could tack a matching smaller cone on the end for about 6 inches more. I'm thinking more like 5 or 6 feet- especially if I end up trying the idea with a Lowther, or an 8" dual cone or something.

[otek]

I have made PVC pipe speakers before- those ones were transmission line, these are mostly not- the vertical pillar is open to the top enclosure but the bottom is sealed, and the top enclosure doesn't work like a transmission line because it is tapered and sealed on the end. Transmission line = pokey and sluggish, tapered to a point = lively as hell.

The thing is, I'm not sure the size of these drivers would be best served by a TL design, either. Though I'm sure it would be interesting to try. :grin:

I am _seriously_ liking the liveliness effect of having the column of air behind the speaker be essentially horn-loaded.

Eeerr... now you threw me off, because you just went through telling me that both tubes were sealed on the end. Also, it wouldn't be horn-loaded unless the taper was going the other way - i.e. from small to large.

By your description this appears to be more of an infinite baffle (closed box) design, since the "cabinet" doesn't appear to be vented in any way.

These are crazy toys with unusual sound characteristics, and even more unusual build qualities.

I realize that you are just experimenting, but "crazy" and "unusual" aren't exactly key words for me when I'm looking for a listening reference.

The interesting part to me about this speaker is that it's sort of a "coincident array". This idea is not exactly new, but there are precious few examples on the market, like the Swedish ESE (below).

[frnjplayer]

If I do a long skinny ski-pole version, with a copper pipe down the middle glued onto the alnico magnet, the mass of the pipe will brace the voice coil assembly of the driver, and I can cut holes in the end of the tube so that once waves reach the end of the cone, the air can leak into another air resevoir that would actually be more of a transmission line, being a long empty tube. This would also provide a backbone to the speaker. I figure if the volume of the cone ends up similar to the volume of an optimal rectangular box, it'll be a suitable size. Logically if the cone is infinitely long it's no different than having a long tube, and that is like transmission line loading which I've tried and disliked :)

I hereby move that you get a couple of 8" sonotubes and build a sub to match.


That would be great fun.

[chrisj]

Otek- OK, so it's not really horn loading. I just need language to explain how the acoustic impedance of the back chamber changes as it approaches the driver, because it behaves differently from a transmission line. I tried that and it was very inefficient and pokey. This is surprisingly efficient and unpokey, so the word 'horn' kept coming to mind.

I keep thinking what it would be like if you took big 1/4 sections of a cylinder and did a spherical horn tapering to a point, and then put one of these little drivers at the place in the horn where the throat width would fit the driver... I definitely see similarities, somehow.

*g* yah, good idea on the bassbins there, not something I'm doing today tho. Anytime you can cut a cylinder in halves offset and the long way and reassemble it flipped over you can make one of these and have it sound good instead of like complete ass :) sounds like a weekend project!

[otek]

it behaves differently from a transmission line. I tried that and it was very inefficient and pokey.

My language skills sorta fizz out a few clicks south of "pokey", but as for "inefficient" I can only wholeheartedly agree - an all too well known calling card of TL designs is low efficiency. The upside, of course, is very deep and linear bass response - one of the reasons TL designs is normally used for bigger drivers. Also, Transmission Lines generally have very smooth impedance.

The trick with a TL enlosure is the damping. It has to decrease evenly throughout the length of the duct. A breathing material is needed, so bubble wrap would not be very suitable.

[Grapestomper]

It only has to be three times the length of a cylinder with the same volume of a rectangular enclosure that would get halfdecent bass for the driver :)

However, that's still pretty tricky. Not even jumbo 3*30 degree industrial yarn cones quite manage it... ...I'm thinking more like 5 or 6 feet- especially if I end up trying the idea with a Lowther, or an 8" dual cone or something.

I can't think of anything pre-made that would work, but here's how I'd go about trying to make one:

Get a couple large pieces of heavy paper and roll up a template of the shape you want and tape it together. Hang it from a ceiling in the garage or some such place, and go at it with papier-mache; probably large, wide strips.

Dry it out, trim it up, and Bob's yer wachacall mom's brother.

Not sure if it's worth the time involved, but it's pretty damn cheap!

M

[chrisj]

Might work particularly since I have large quantities of paper sheets- a shipping supply company (ULine) sold me a moving kit that included a big stack of 3'x4' newsprint. Like a four inch thick stack. Good raw materials :)

[blackieC]

I still can't decide if it looks more like ET or Johnny 5.

[otek]

Johnny 5.

CLASSIC shit. :D

[volthause]

Need more input!

[chrisj]

More inputs? Like 'this is the CD inputs, this is the radio'? Or more input like you need to specify how it's made? Shoot :) I'll see if it seems possible.

[volthause]

That comment was in reference to the Johnny 5 post. Come on man, haven't you seen Short Circuit?

[chrisj]

Awww- no I haven't. How much of a cultural cretin does that make me? :)