Beyond the Ariel - Page 285 - diyAudio
Go Back   Home > Forums > Loudspeakers > Multi-Way

Multi-Way Conventional loudspeakers with crossovers

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 15th December 2007, 01:02 AM   #2841
diyAudio Member
 
Lynn Olson's Avatar
 
Join Date: Jul 2004
Location: Northern Colorado
If the Altec/GPA 290/390 is this good, that certainly makes it promising.

JohnK: the discussion of the OB is not about EQ, but about controlling IM distortion below the baffle peak. Yes, there are some audiophile drivers with low distortion, but going the prosound + large area route keeps distortion down and also retains system headroom as well. I know what too-small overboosted audiophile drivers sound like - bad, with a very compressed sound and obviously limited headroom.

There were several systems like this at the RMAF. They sounded thin, compressed, and had very poor dynamics. Spacious, yes, of course. But the dynamics were no better than electrostats, but without the see-through transparency, either. I can't see any way horn dynamics can be mimicked by small drivers with lots of EQ and amplifier power.
Attached Images
File Type: jpg 290_fr.jpg (77.9 KB, 521 views)
  Reply With Quote
Old 15th December 2007, 01:41 AM   #2842
diyAudio Member
 
Lynn Olson's Avatar
 
Join Date: Jul 2004
Location: Northern Colorado
I expect to build several mid and HF assemblies, measure them, and listen at some length. The bass module is going to be heavy enough, with 3 or 4 15-inch drivers, that it will have a shelf on the top so the Mid and HF modules can be skated back and forth and independently adjusted, replaced, and fine-tuned.

No idea which mid configuration will sound better. The double-RAAL will be compared to a good but not insane compression-driver + horn/waveguide. No Gotos, Ales, or TAD, in other words. You gotta draw the line somewhere, and multi-thousand-dollar raw drivers fall in that category.

The overall system, as mentioned in the "Better Crossovers" thread, will be bi-amped with a pro EQ/crossover used for the rough adjustments, and either a prosound or good-quality PP pentode tube amp for the bass module. The Karna amplifier will handle everything above 300~600 Hz, depending on the crossover frequency for the mid/high module.
  Reply With Quote
Old 15th December 2007, 02:03 AM   #2843
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Are you going to try central hinges, for angling the woofers in the LF construction?
  Reply With Quote
Old 15th December 2007, 04:24 AM   #2844
Banned
 
Join Date: Feb 2004
Location: Portal 2012
Quote:
Originally posted by Lynn Olson
I expect to build several mid and HF assemblies, measure them, and listen at some length. The bass module is going to be heavy enough, with 3 or 4 15-inch drivers, that it will have a shelf on the top so the Mid and HF modules can be skated back and forth and independently adjusted, replaced, and fine-tuned.

No idea which mid configuration will sound better. The double-RAAL will be compared to a good but not insane compression-driver + horn/waveguide. No Gotos, Ales, or TAD, in other words. You gotta draw the line somewhere, and multi-thousand-dollar raw drivers fall in that category.

The overall system, as mentioned in the "Better Crossovers" thread, will be bi-amped with a pro EQ/crossover used for the rough adjustments, and either a prosound or good-quality PP pentode tube amp for the bass module. The Karna amplifier will handle everything above 300~600 Hz, depending on the crossover frequency for the mid/high module.

I'm glad to see you heading this direction. (In my opinion) you will end up with an incredible sounding system going this way. You seem to be skipping to where I have led myself to after approx 8 years of building high efficiency systems.

To perfect the multi driver bass system will get your project much closer to where you'll want to dig in deeper. Even with my cheap 10's it's sooooooo nice and refreshing to hear all the low notes free from the box and compression or horn colorations.

I didn't realize Great Plains is bringing back the 290. I think you'll have a hard side deciding between the raw immediacy of the phenolic compression driver compared to the wonderful tone and deep color saturation of a big motor low mass cone. -- I'm to the point where I crave both - But-----

I really think you can have your cake and eat it too with the *right* cone mid. The 18 Sound 6" may be better than the B&C and there may be others. What's nice about the cones is they won't break the bank experimenting with them.

If you want, I'll share my cone drivers if you share yours......
  Reply With Quote
Old 15th December 2007, 05:44 AM   #2845
Cappy is offline Cappy  United States
diyAudio Member
 
Join Date: Feb 2004
Location: Southern Willamette Valley
Regarding:

<<I think you'll have a hard side deciding between the raw immediacy of the phenolic compression driver compared to the wonderful tone and deep color saturation of a big motor low mass cone. -- I'm to the point where I crave both ->>

Why choose? Use a cone for 8 months and a compression driver for 4 months, or visa versa...

The concept of a wife AND a mistress has been around for thousands of years for a reason!
  Reply With Quote
Old 15th December 2007, 06:56 AM   #2846
jerko is offline jerko  United States
diyAudio Member
 
Join Date: Jan 2005
Location: earth
Quote:
Originally posted by Lynn Olson


I may have heard the same phonograph some time in the early Seventies, when I was visiting my retired parents in Berkeley. I was idly strolling along Telegraph Avenue, and heard a really good opera singer inside a small arcade. Drawn off the busy street by the sound, I walked inside, turned a corner and was astonished to find a big Edison acoustic phonograph playing a thick, blue-colored (must have vertical-cut) 12" disk. I stood and listened to the whole length of the record - it really was a good approximation of a somebody stranding right there and singing, and singing damn good classical opera.

Was it hifi? No. But it did some things hifi systems don't - in important ways, it sounded real. No "electronic" colorations at all, and the mechanical colorations had somehow been ingeniously concealed for the human voice. The orchestral backing was pretty funky-sounding, but there wasn't much of it, which was just as well.

This was a truly educational experience - I was already indoctrinated into high-end audio, having subscribed to J. Gordon Holt's early Stereophile for several years at that time, owned exotica like a Thorens TD-125, Rabco SL-8E, and a Stanton 681A cartridge, and persuaded my sister to buy Fulton FMI-80 speakers (which I think she still owns - good speakers).

But that top-of-the-line Edison gramophone made me think about a lot of unquestioned assumptions I'd made about audio. It wasn't all about frequency response, impulse response, and freedom from resonance. There's a very direct and immediate perception of realness - so strong it brought me off the never-ending circus of Telegraph Avenue on a summer's day - into a secluded courtyard, and to a revelatory experience I never would have expected.

This openness to the unexpected has a been a gift, one of the deepest and most essential parts of the human spiritual endowment, and I am absolutely sure we are all born with it. I am afraid, though, that culture, and worse, education, beats it out of many of us, leaving room for only small deviations from the "known" and "true". I am also afraid that perception itself is strongly affected by prior experience, shutting off entire worlds of perception if we "already know" that certain things are impossible.

I probably offend many Western-trained rationalists with my somewhat unconscious acceptance of Taoist and Buddhist notions of "relative" and "absolute" truth. In the simplest terms, Taoists and Buddhists believe that any truth that can be described, or written down in a book, is a "relative" truth, subject to change with culture and time, and "absolute" truths are essentially ineffable, beyond all description (without gross distortion), and can only be directly experienced.

As a result, all of the world's religions are extremely distorted and limited descriptions of experiences (by the founders, saints, and prophets) that cannot be described with any accuracy at all.

This notion, of course, is abhorrent to all fundamentalists, who view Scripture as literally hand-written by God, or Newton, depending on persuasion. I guess it makes sense - if you believe Absolutes already exist, and not only that, must be defended to-the-death against barbarians and infidels, the entire notion of "absolute" and "relative" truths is the most appalling and dangerous heresy possible, because it is so seductive and intellectually appealing.

I also believe that Science as a social movement has very slowly assumed the role of religion in Western culture, right down to the white gowns, ceremonies like the Nobel Prizes, hidden power struggles, and the growth of competing sects and guilds. There are a lot of unquestioned metaphysical assumptions that are pretty obvious to Taoists and Buddhists - this doesn't undermine scientific method, which will always be useful, but the science-as-worldview does have dogmatic and emotionally defended religious overtones.

I take a more relativistic stance that basically "everything we know" could easily be proven utterly, and completely, wrong in the next several hundred years, and thus hardly makes a serious claim to any kind of "absolute" truth. A short look at the history of ideas indicates what happened in the past is happening to us right now - we are not exempt from history, but are right in the middle of it. What we have is an extremely powerful working tool (and should not be discarded), but it isn't necessarily the same thing as reality itself.
I know this is mega-late, but I just now read this post.

I guess I should start out with what one of my physics professors said: "Everything is an approximation." It is important to note that he didn't say "Everything could be completely wrong." Newton wasn't completely wrong about gravity; his approximation to what we have now observed about gravity is extremely good in many situations. Einstein improved the model of gravity to the extent that we haven't found a disagreement with General Relativity yet, but it is expected that there will be disagreement at higher energies than we have observed. Even then, Einstein will not have been "wrong"; the theory will still work just fine for all but the highest energies.

This worldview agrees with yours about our ideas about the world not really being how the world is, but disagrees with yours when you say that "basically "everything we know" could easily be proven utterly, and completely, wrong in the next several hundred years" because when a theory is tested with experiment (or in the case of something like astronomy, observation) the theories are known to give correct predictions at a certain range of values. The probability of many independent experiments saying that a theory works when it doesn't is about as close to zero as any probability gets.

I don't know. It just irks me when people say that we don't really know anything. Something we know is that the Standard Model and General Relativity both work on every energy scale we have tested them at. These happen to be the most accurate descriptions of anything that mankind has ever produced, and that really is something.
  Reply With Quote
Old 15th December 2007, 07:41 AM   #2847
diyAudio Member
 
Lynn Olson's Avatar
 
Join Date: Jul 2004
Location: Northern Colorado
Quote:
Originally posted by Magnetar


To perfect the multi driver bass system will get your project much closer to where you'll want to dig in deeper. Even with my cheap 10's it's sooooooo nice and refreshing to hear all the low notes free from the box and compression or horn colorations.

I didn't realize Great Plains is bringing back the 290. I think you'll have a hard side deciding between the raw immediacy of the phenolic compression driver compared to the wonderful tone and deep color saturation of a big motor low mass cone. -- I'm to the point where I crave both - But-----

I really think you can have your cake and eat it too with the *right* cone mid. The 18 Sound 6" may be better than the B&C and there may be others. What's nice about the cones is they won't break the bank experimenting with them.

If you want, I'll share my cone drivers if you share yours......
Well, as part of research on the 290/390 I saw your many favorable posts about it over in the AA-HE zoo. You've owned and listened to both the 290 and the B&C cone, so I take your comments quite seriously. We may have different sets of subjective impressions, but you're certainly speaking of some of the same things I've heard directly for myself.

I've heard hints of greatness in A4-style systems, and I know there's something of value there. Never was a fan of the A7, 604 Duplex, JBL L100 or L200, but the big dog with the large-format multicell horn is another league altogether. I'm very curious just what a modern Tractrix or LeCleac'h horn can do with a large-format compression driver or a professional-grade cone midrange. Now that I've settled on a 3-way with crossovers in the 400~640 Hz and 3~5 kHz range, it comes down to selecting the right drivers, extensive measuring, and listening at length. JLH is out of the horn-building business, so I'll have to look elsewhere for the Tractrix or LeCleac'h confection to work with these drivers.

Regarding jerko's comment (I like your location, by the way), since I was raised in Japanese and Chinese culture, I take a very long historical view. If the Galactic Federation ever chooses to visit our scenic little tourist attraction, I am confident that most, if not all, of our physics would end up in the junk pile. The scary part is what would be left of our ethics and religions - it's a good question what would survive contact with civilizations thousands, or millions, of years more advanced. This is a very big Galaxy that's been around for many billions of years - I have no doubt somebody is out there.

The only question is when - tomorrow, or 10 million years from now. The radio-wave sphere now has a radius of 90 light-years - good question if there are any monitoring systems in place or not. Guess we'll find out, won't we?

The record of contact of pre-literature cultures when they met a more advanced literate culture is not a happy one - and all of humanity would then be in the same position. The hidden subtext behind the alien-invasion SF genre is the very real record of what happened to native cultures when they disintegrated on contact with more advanced cultures - they basically lost everything, their world-view, their language, their religion, and the physical places where they lived.

Our pint-sized little civilization is only about 10,000 years old, and most of humanity is preoccupied in the same sort of tribal struggles that go back to our prehistory. Only the labels have changed - and the fact that tribalism can now be promoted on TV and the Internet, so wars can engulf the entire planet, not just a scruffy bunch of smelly and greedy warriors armed with bone clubs. In terms of mental age, our civilization is in early adolescence, and is heavily armed with guns, tanks, bombers, missiles, and 20,000 nuclear weapons.

We all have our fingers crossed - we're going to need it, since a rescue by the Galactics, or your favorite semi-friendly deity, seems like a long shot. We'll have to figure it out on our own, as we've done many times before. This century should be interesting.
  Reply With Quote
Old 15th December 2007, 08:31 AM   #2848
diyAudio Member
 
Lynn Olson's Avatar
 
Join Date: Jul 2004
Location: Northern Colorado
Off-topic again. Sorry, mods, just can't help myself. You have to admit, though, you don't see a post combining Altec A4's and UFO's every day, do you? That ought to keep Google busy a little while.
Attached Images
File Type: jpg pf_magazine.jpg (74.7 KB, 1068 views)
  Reply With Quote
Old 15th December 2007, 09:03 AM   #2849
Andy G is offline Andy G  Australia
diyAudio Member
 
Andy G's Avatar
 
Join Date: Apr 2002
Location: Newcastle, Australia
Lynn, please say you have come to some sort of conclusion on "what's next".

Its been one mighty long thread, and I would really like to see what comes of all the discussion.

Its time to build !
  Reply With Quote
Old 15th December 2007, 09:12 AM   #2850
diyAudio Member
 
Lynn Olson's Avatar
 
Join Date: Jul 2004
Location: Northern Colorado
Illustration Credit: Bruce Walker, published in Positive Feedback magazine in the Summer 1994 issue, opposite the Ongaku review I wrote on page 138. Thanks to David Robinson for publishing a magazine where we could write what we wanted - and there was no party line to follow.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



New To Site? Need Help?

All times are GMT. The time now is 03:05 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2