Gravity Well Of A DarkStar

ooheadsoo · « **Reply #120 on:** 5 Jun 2005, 06:27 am »

Oh, in that case, it's easy as pie. Just surf on over to mcmaster.com whenever you have a spare moment and type in "cork." They have cork sheets from 1/2" thick to 4" thick. 1/2" and 1" are the most economical.

I was thinking...If this (http://www.visaton.de/english/artikel/art_787_6_25.html) works, then why wouldn't the dipole in a corner also work at least in a semi half-assed fashion?

-Richard- · « **Reply #121 on:** 5 Jun 2005, 07:56 am »

Hi ooheadsoo,

Yes...very nice resource...I'll call them monday and order some 1" sheets.

Question: Why do I get huge yellow ugly round heads instead of images on
my computer on these and other threads...for example mcgsxr's images on
thread #10...I just get those yellow heads???

Also: How do I post images in this thread...I did an illustration of an idea
for the corner speaker which I have as a pdf...but I do not know how to post
it...any idea?

Thanks for your help...deeply appreciate it.

Warm regards -Richard-

Dmason · « **Reply #122 on:** 5 Jun 2005, 01:12 pm »

I have two of them working very well, into the corners. Interesting things happen when you "seal" one baffle edge to an adjoining wall, as with the floor, or lower edge, you now have a situation where the driver is seeing an infinite baffle along half of its baffle perimeters. The amount of gain is impressive.

Taoist Speaker Design Philsophy -- The best kind of box is no box.

If you go to www.diyaudio.com and search the word "baffled" you will come across a long thread of 300 posts on open baffle development, using single drivers, and Thorsten Loesch has included some pictures of his OB in the corners at his place. His baffle dimensions and choice of materials are almost identical to the ones I am using right now, and will give you a good idea of corner placement, size, visual characteristics of a black eight inch driver in a clear baffle, for you to determine how WAF this type of thing can actually be. The thread is very informative. It is also interesting that Thorsten, who is a high-turnover speaker guy like myself, has been stuck on this configuration for quite some time now

mcgsxr · « **Reply #123 on:** 5 Jun 2005, 02:37 pm »

Cool that you guys have found a cork distributor in the US, Jelinek, a major Canadian brand, is located next to where I live, so I should be sorted for that, when I come to play around with cork.

Quick question about resistors - I can find 16-22Ohm resistors, but I am unsure what wattage they should be rated for - I am using a 30wpc amp, and see many in the .25, .5, 1, 5, 12w ratings.

Ideas?

Dmason · « **Reply #124 on:** 5 Jun 2005, 03:10 pm »

Mark

5 watts into the Visatons would have Otto Jelinek himself calling to complain.

5 should do okay, unless you play metal while drinking Labatts 50 in the winter. If you are paralleling resistors a la Zobel, the cheapo sandcast stuff is okay. If series, you might want to see what else they have.

San Onofre north of the ConEd parking lot has been taken over by its owners the USMC, and they are going to be builiding "townhouses" for married commissioned officers there, by the river outlet. Soon, all that, the Trestles pathway, and San Mateo Point access will be a thing of the past.

mcgsxr · « **Reply #125 on:** 5 Jun 2005, 04:03 pm »

Dan, thanks for the tips on the resistors, I will work on that.

In the meantime, I have something VERY interesting to share. I have been battling with these speakers, and the bass problem in my room. Dmason suggested that I corner load the other baffle near my water heater access door (hey, good eye!) but that does make it impossible to have a sweet spot, due to that nasty pine bar (former owner, and since I am moving anyway...).

I was thinking last night about digital EQ, and how that might sound. It kept coming back to me, that this sound really needs a boost in the bass for me. I was thinking, hmmmn, how can I arrange that?

Well, it came to me this AM, on my drive over to Tim Hortons (national coffee shop of Canada doncha know?) - loudness. This sound I have needs a loudness button. Now, if you are easily sickened, or love audio gear more that music, for god's sake - STOP READING NOW! If, however, you are interested to see what a bent Canuck will do, to test out some theories.... check this out!

I was listening to a news broadcast in the family room, on the JVC X-1 that my wife bought me for Xmas. It is one of those little "executive" units, that uses JVC's much loved Hybrid Feedback amplification systems. It sounds decent, with the single driver speakers it came with. It has a loudness button....

Oh yeah, you KNOW what is coming...

My daughter heads off to nap time, I sprint downstairs, find some mismatched zip cord in the closet, transport the JVC main body (tuner/amp/cd player) to the basement, and hook it up.

Hmmmn, well F#$% me! Now THAT is great! Just the bottom end lift this speaker needed, in my basement. How can this work so well?

Sure, it gives up ultimate transparency, top end smoothness, and realism to my Nakamichi cd player/Monarchy DIP/Bolder Mensa/Hagerman Clarinet/Bolder Teac combo.... but the bass dude!

Laugh if you want, but I have found out exactly what Dan is talking about - get a Behringer digital EQ, boost that bass the audiophile approved way, and retain the magic of my full system? Geez, what can I sell to make THAT happen?

Here are some pics, for the truly deprived!

World's largest ghetto blaster!

Looks like a toadstool, in front of my rack.

Here is the front of the JVC X1.

And the top of the unit - best US$114 ever spent on eBay!

Wonder what that Vinnie modded Sharp would do with this....

Dmason · « **Reply #126 on:** 5 Jun 2005, 04:29 pm »

If it sounds good, it IS good! What a perfect means to an end. The little JVC I bet sounds way more than okay. It never even occured to me to try the ES1 with them. I will do that today!! This could make the recipe even more simple, mo cheapa, mo betta.

Less=More

With some induced lift, the B200 will perform waaaay beyond all the baffle roll off and physics would suggest, indicating that this whole open baffle thing is more art than science, practice is truly at odds with theory in this realm.

Like Nigel Barfind says, the B200 will do real bass. It passes the UFO TOFU test with flying colors. Loaded into the corners, the baffle's sound will have you openly baffled, once you start hearing bass fundamentals playing, and this open, glorious sound, sans box resonances, phase distortions, backwave cone ringing, all that sonic grunge you thought you werent hearing. Once gone, you realize what all you WERE hearing. This seems to be why once most people hit on the open baffle thing, they not often return to box speakers. When you add highly resolving amplifiers like Vinnie's with highly resolving drivers like the Visaton, add an uncommon synergy between the two, et voila: le son du excellence.

nodiak · « **Reply #127 on:** 5 Jun 2005, 05:19 pm »

A bisected oak wine barrel could be interesting for a B200 OB. Wonder if that guy at that parking lot is selling those today. Don

powerbench · « **Reply #128 on:** 5 Jun 2005, 05:36 pm »

If it works don't fix it...

-Richard- · « **Reply #129 on:** 5 Jun 2005, 05:44 pm »

This time the pics came through...nice mcgsxr!

I wonder if the baffles could be thinner without loosing
any of the benefits of the wide board...once they are
placed in the corners?

Warm regards -Richard-

nodiak · « **Reply #130 on:** 5 Jun 2005, 07:12 pm »

A Red Wine barrel of course...
Offered as a diy idea to mate with Vinnies amps.

nodiak · « **Reply #131 on:** 5 Jun 2005, 08:00 pm »

http://search.ebay.com/wine-barrel_W0QQfromZR8QQfrtsZ0QQfsooZ1QQfsopZ1

from$45 each up plus $59 shipping in usa.

if your decorator approves

Dave G · « **Reply #132 on:** 5 Jun 2005, 08:37 pm »

Just be sure not to use a barrel from a f***ing Merlot!

-Richard- · « **Reply #133 on:** 5 Jun 2005, 10:16 pm »

Hi nodiak,

Thanks for the websit link to the speaker diagrams/explanations...
very interesting and an education...beautifully worked out...
like the animated explanations one finds these days next to
museum dioramas...

Warm regards -Richard-

nodiak · « **Reply #134 on:** 6 Jun 2005, 12:08 am »

Hi Richard, you're welcome. That is something I'll use too, I just found it yesterday. I found the article on the construction of the Krisnamurti school in Ojai where you work. It's just 2 pages with 3 pictures. It's in Dome Builders Handbook No. 2. I love the cedar shake work, "resembles a rippling lake surface". Looks like a beautiful place to be.

The wine barrel link to ebay was a bit of a flop. The good ones went off the list right after i put it up here. But the same business is at http://www.usedwinebarrels.com/
I realize it's an odd idea, but the size and shape is great for an OB. Curved on both the horizontal and vertical access should help with reflections, tho subtley probably. That's nice wood too. Bit of work to half one, cut thru the metal bands, etc. Sand it or not, or take it to the sandblaster...cut the hole, oil it up. I'm odd enough to try it.

All this OBism got me to put up my Fostex FE167E ob's again. They have a very low qts and a short xmax so don't like this job. The mids and highs are great, but no bass, filling in with 12's. I'll have to join this wave of B200 users here, after the surf trip

Don

-Richard- · « **Reply #135 on:** 6 Jun 2005, 02:43 am »

Hi nodiak,

You are quite right...the Oak Grove School is very beautiful...
the architecture of all the buildings are student friendly and
inviting...they have a large expanse of land to roam around
in or play sports...and of course the mountains rise to imposing
heights all around it...defying the ages with their dignity and power.

There are quite a few private grammar and high schools in Ojai...
still a safe place for children and young adults to grow...and surrounded
by a vast wilderness with bears, cougars and rattle snakes...nice!

Warm regards -Richard-

powerbench · « **Reply #136 on:** 6 Jun 2005, 05:10 am »

OK since we are exploring the usage of various designs or materials has any one ever though of casting concrete with some sort of panel ie MDF to prevent cabinet resonace>?Any thoughts on this??

I was thinking of building a concrete form adding a front panel of mdf or plywood to mount the driver with enough room to easily remove it.That is if it sounded like crap.i would remove it...

Basically an open baffle design but making the concrete 3-4 in thick.This I would mount on a solid wood stand 4x4 or 6x6 with a base.Too all you pseudo engineers out there

is there any benefit to this??

barfind · « **Reply #137 on:** 6 Jun 2005, 06:18 am »

Dont feel to bad about the JVC. I put my PP tube amp back in my OB system. It is an intergrated amp with tone controls. This amp has been modded heavily, and gives nothing away to my 300B SET. Well I turned the bass control to 3o'clock and WHAM!!!. The bass from the B200 is great. I have found from 6 months of playing with this driver, that once it is run-in, it only needs a little bit of help in the bass department. This has a very smoothing effect on the response in OB. SO, even though tone controls may be heavily bagged by some, line level contouring can be as transperant as none,done right.

Nigel

-Richard- · « **Reply #138 on:** 6 Jun 2005, 06:35 am »

Hi powerbench,

I would imagine the weight of the thing would challenge you
physically and make the options for moving these beasties
around rather daunting...

Is there a material that could mimic what concrete brings to the
equation in regards to resonances that is much lighter in weight?

For example...in some forms of contemporary architecture when
working with amorphous forms or forms that are not perpendicular but
"organic" and continuous in nature...some architects have devised a
"form" like a large ballon that they then spray a concrete like mixture onto...
more porous and perhaps lighter in weight as well compared to the stuff
you mix yourself...

There is also a sandwich like board used for architecture that does not
need an understructure...made of a concrete like foam that is in the center
with composite wood panels glued to both sides...referred to as SIPS...
light in weight compared to concrete...and they come ready made...
they cut easily as well...

Warm regards -Richard-

nodiak · « **Reply #139 on:** 6 Jun 2005, 06:36 am »

Any material used to make an enclosure can be hit with a hammer as well as a soft mallet, open hand, or cooked carrot to get an idea what resonances and sonic flavor it will add to the speaker system. We also used to talk ,scream and yell into cabinets we made to hear the cavity resonance.
OB avoids the hollow sounding cavity resonances of speaker cabinets, which seems helpful in getting to the music on the recording. I bet a concrete OB would have some ring to it tho. just an opinion.
I built some speakers using sonotube, with mdf baffles cut at an angle top to bottom. I glued rocks to the sonotubes exterior to stiffen it and make it look weird. Worked for both! You could hear the rocks brightness (probably, was studying art and philosophy at the time, so I'm not sure what was true). Sold the pair to an art teacher...Another pair used a sonotube inside a mdf enclosure with sand in between, you could here the ocean...not really, but you could tell it was much less resonant. I like reading about the horn enclosures people have made, and some transmission lines, that use dense plywood for it's sonic textures.
Imo the experiment you're thinking about just screams WHEELS! i put wheels on heavy speaker projects, figured that out after I hit 40 or so

Don