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post #541 of 11387 Old 12-15-2010, 12:29 PM
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Originally Posted by coctostan View Post
I'd still like to build a SEOS that is around 90x50 and 20" wide with a big mouth roundover. I think that would hold pattern solidly to 800-900hz which would be perfect for a TD15m. It would be a big speaker but it would be more of an ultimate performer rather than a semi-mainstream speaker. For this group I think the 15" wide version would be good and allow an easy 1200hz crossover to a 12" woofer.
I think you're off a notch on matching woofers and WG's.

I believe Geddes XO's the 12" Abbey at 1200 Hz and 15" Summa at 900 Hz.

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post #542 of 11387 Old 12-15-2010, 12:32 PM
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Originally Posted by penngray View Post
Paul W. XOed at 700Hz with the XT1464 18sound waveguide which is 15" wide, I was using that as my reference point for lower XOs.

No arguement with me on using the 1200Hz XO with this 15" version if they are using 12" woofers but most 15" woofers will have matching directivity lower.

Im trying to figure out some assumptions though, lots of discussion around the assumption that this SEOS might be mainstream. I do not hold that opinion at all, I think the QSC Clone will be the popular choice (it already is) and I think the SEOS will cost to much per unit to be that popular (remember 18sound waveguides are very good but they cost a lot too). Im hoping that is wrong but there is a reason no one has build a mass production run of these designs and that reason has been discussed many times on DIYaudio.com.
Penn, first, the XT1464 is a 60deg horizontal horn thus requiring a narrower profile. Second, 18sound says it holds pattern to 800hz and is only CD from 1.5khz up. So 15in wide is good to 800hz for a 60deg horn. I'd estimate about 20in wide for a 90deg pattern which I'd prefer. IMO, the reason Geddes sticks to ~70deg is because he is using a round WG and the narrower WG reduces his CTC spacing thus widening his vertical null window.

(as an aside, it appears the XT1464 is a super ellipse)

I'm sure Paul W's Raptor is nice, but I think it makes significant compromises I'd prefer not to make if I don't need to.

I wouldn't mind a much larger WG for this project, but most people seem to want the more versatile size. I'm not sure there is an appreciable improvement by going to a lower xover with wider WG and a 15" woofer since I haven't tried. Theoretically it has advantages but that only means so much.
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post #543 of 11387 Old 12-15-2010, 12:36 PM
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Originally Posted by noah katz View Post
I think you're off a notch on matching woofers and WG's.

I believe Geddes XO's the 12" Abbey at 1200 Hz and 15" Summa at 900 Hz.
Maybe I don't understand your post, but I was targeting 1200hz for the 12" woofer and ~15" WG and 900hz for the 15" woofer and ~20" WG. Geddes is using narrower 70deg WGs which should hold require a narrower mouth to hold pattern lower hence his match of 15" WG to 15" woofer.
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post #544 of 11387 Old 12-15-2010, 01:11 PM
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gotcha

Quote:
Originally Posted by coctostan View Post
Maybe I don't understand your post, but I was targeting 1200hz for the 12" woofer and ~15" WG and 900hz for the 15" woofer and ~20" WG. Geddes is using narrower 70deg WGs which should hold require a narrower mouth to hold pattern lower hence his match of 15" WG to 15" woofer.

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post #545 of 11387 Old 12-15-2010, 01:53 PM
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Quote:
Originally Posted by coctostan View Post

Penn, first, the XT1464 is a 60deg horizontal horn thus requiring a narrower profile. Second, 18sound says it holds pattern to 800hz and is only CD from 1.5khz up. So 15in wide is good to 800hz for a 60deg horn. I'd estimate about 20in wide for a 90deg pattern which I'd prefer. IMO, the reason Geddes sticks to ~70deg is because he is using a round WG and the narrower WG reduces his CTC spacing thus widening his vertical null window.

(as an aside, it appears the XT1464 is a super ellipse)

I'm sure Paul W's Raptor is nice, but I think it makes significant compromises I'd prefer not to make if I don't need to.

There are many choices we all need to make. Its really simple for me.....If I can build anything remotely close to what Paul W. builds then I will be extremely happy.

You raised a good point though, maybe we should focus on 70deg and not 90deg controlled directivity??



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I wouldn't mind a much larger WG for this project, but most people seem to want the more versatile size. I'm not sure there is an appreciable improvement by going to a lower xover with wider WG and a 15" woofer since I haven't tried. Theoretically it has advantages but that only means so much.

That is why I have to build and listen My POV on this topic isnt really concerned with what most people might want. Im thinking that isnt going to matter in the end. Not to sound like a broken record but Im not confident at all about this special waveguide having any sort of meaningful volume no matter if its 12", 15", 1" CD or 1.4" CD....Its price point will make it about as special as buying the 18sound XT1086 waveguides. THe QSC will dominate the what most people will want to buy if they are buying anything at all. So if its special then lets make it for the few who are really willing to spend the money. Again if you read other forums you will know there are vastly different opinions on what people want.

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post #546 of 11387 Old 12-15-2010, 01:56 PM
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Originally Posted by noah katz View Post

I think you're off a notch on matching woofers and WG's.

I believe Geddes XO's the 12" Abbey at 1200 Hz and 15" Summa at 900 Hz.

I thought Geddes XOs the Abbeys below 1KHz, He has posted many times that he wants to keep XOs out of that critical >1KHz range (yep, I agree with that opinion too )

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post #547 of 11387 Old 12-15-2010, 02:05 PM
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Originally Posted by LBDiver View Post

What happened to making a prototype? Eric are you trending towards full production of the decided design? What type of mold are you having made? Are you having it produced by your friend, or Jzagaja?

It seems that prototype and production all in one can give us the best price target.

EricH, has the EOS-15 prototype files already, Im not sure the local company did anything or if the costs where just too high in the end but Jzagaja or Auto-Tech has all the engineering/manufacturing in place for this already. The biggest problem is the shipping costs from Poland to USA.

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post #548 of 11387 Old 12-15-2010, 02:33 PM
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Originally Posted by penngray View Post

I thought Geddes XOs the Abbeys below 1KHz, He has posted many times that he wants to keep XOs out of that critical >1KHz range (yep, I agree with that opinion too )

I'm not sure, but I thought he scaled XO freq directly with woofer/WG size, which makes perfect sense technically.

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post #549 of 11387 Old 12-15-2010, 02:40 PM
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Originally Posted by noah katz View Post

I'm not sure, but I thought he scaled XO freq directly with woofer/WG size, which makes perfect sense technically.

Sure it would make sense but I have had a lot of questions about his designs over the past 3 years because I have been trying to duplicate them in many ways. I always asked about the < 1KHz reason and he really wanted the XO below 1KHz for voicing reasons.

You can see the XO point is below 1KHz.
http://www.gedlee.com/abbey.htm


Heck it looks like 700Hz, hmmmm.... So all of you guys now will post saying its a bad XO or something??


Its just another choice/compromise. Its amazing/scary how many different ways we can build a speaker Again, Im okay if I can build a speaker remotely close to what Geddes does or what Paul W. does and Im okay if others think those speaker designs have serious flaws. I mean are we not better having these seriously flawed speakers then buying $700 comerical designs out there today that have "other" serious issues?

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post #550 of 11387 Old 12-15-2010, 03:02 PM
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Originally Posted by penngray View Post

It seems that prototype and production all in one can give us the best price target.

EricH, has the EOS-15 prototype files already, Im not sure the local company did anything or if the costs where just too high in the end but Jzagaja or Auto-Tech has all the engineering/manufacturing in place for this already. The biggest problem is the shipping costs from Poland to USA.

As in make a prototype mold that can be re-purposed for a short run? I was just wondering because it went from finding out -> ready to drop a few thousand to get this thing going by the end of the week. Nothing about who, what, where, you know all the in-between stuff.

What's the cost breakdown of buying from Jzagaja, unit cost, shippings cost, purchase minimum? I thought a week or 2 ago someone posted they were getting out of the WG business, and weren't going to produce the mummies? But now you have 12" OS's on order and hence I'm a little lost on what the deal is. What are you paying for shipping on the OS's? These won't be much bigger as the design stands so I figure the cost would be comparable.`
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post #551 of 11387 Old 12-15-2010, 03:03 PM
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Normalized directivity sonograms for some Autotech horns to see differences.
LL
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post #552 of 11387 Old 12-15-2010, 03:26 PM
 
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Originally Posted by ZilchLab View Post

The bolt-on D220Ti is a surprisingly good performer on 152i. I A/B'd it with Deluxe and, unless it was just the day, I'd start with that and upgrade later to DE250 if you find it to be inadequate. Both designs are documented here:

http://techtalk.parts-express.com/sh...d.php?t=215536

Woofer? Deluxe's 3012LF is my favorite, but others are building using the Dayton PA in SR with satisfaction.


You keep saying that, Penn, but it's wrong -- Parham told you so, and Geddes as well. You need to build and measure to prove your contention here. CTC is a WAY bigger deal than you'd like to pretend it to be. Yes, you can steer the forward axis with delay, but that does not change the fundamental height of a compromised forward vertical lobe....

Zilch, In your link (looking at the chart) I do not see a crossover for the 3012LF paired with the D220Ti. Which crossover should I be looking at?
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post #553 of 11387 Old 12-15-2010, 03:33 PM
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Originally Posted by LBDiver View Post

As in make a prototype mold that can be re-purposed for a short run? I was just wondering because it went from finding out -> ready to drop a few thousand to get this thing going by the end of the week. Nothing about who, what, where, you know all the in-between stuff.

What's the cost breakdown of buying from Jzagaja, unit cost, shippings cost, purchase minimum? I thought a week or 2 ago someone posted they were getting out of the WG business, and weren't going to produce the mummies? But now you have 12" OS's on order and hence I'm a little lost on what the deal is. What are you paying for shipping on the OS's? These won't be much bigger as the design stands so I figure the cost would be comparable.`

I would have to search for the price breakdown again. It was posted somewhere on the group buy thread. The SEOS-15 would not be on it but you could get a sense of shipping costs and price tags of waveguides. Lets just say they are going to be as much as buying 18sound waveguides.

I was the one that posted they are not getting into the waveguide product business because is what Jzagaja told me. I think they see this and a buy group opportunity sort of a one shot deal for some profit. It has been hard to findout what is really going on and I also thought we would be finding a manufacturing option in the USA.

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post #554 of 11387 Old 12-15-2010, 03:55 PM
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Originally Posted by LBDiver View Post

As in make a prototype mold that can be re-purposed for a short run? I was just wondering because it went from finding out -> ready to drop a few thousand to get this thing going by the end of the week. Nothing about who, what, where, you know all the in-between stuff.

What's the cost breakdown of buying from Jzagaja, unit cost, shippings cost, purchase minimum? I thought a week or 2 ago someone posted they were getting out of the WG business, and weren't going to produce the mummies? But now you have 12" OS's on order and hence I'm a little lost on what the deal is. What are you paying for shipping on the OS's? These won't be much bigger as the design stands so I figure the cost would be comparable.`

I'm still on this, don't worry. I hope no one thinks a prototype can be made in a week! Heck, people can barely even agree on what to build just yet. I've been willing to get the prototype built, and the ball is rolling. So.......people just need to calm down. After the first steps are done, I will be looking at pricing per unit. There's no way to really know that right now. I've got estimates from the builder on the final pieces, but they're just estimates, so they could change a LOT depending on interest.


The more I read in this thread and the farther it goes, the worse it seems to get with regards to the project design. At first everyone was chomping at the bits to get this done. Not so much anymore......no one knows how it might sound, it may not sell, too small, wrong shape, it may be dead in the water, etc, etc. If people thought the QSC was the end all due to price, I would've driven up to Parts Express, ordered how ever many was needed to get the shipment, and went that route. They're only like 30 minutes away from me.

Trust me, I'm working behind the scenes to get this done. I just wish people would help out to narrow things down and agree to something. I'm not a pro WG designer, I know nearly as much as others at this point. But I've seen thread after thread die when it comes to actually building something. I didn't want that to happen here, so I'm trying to help out in some way by contacting local companies and others that can make this happen.

But if anyone wants an SEOS-15 next week, I'd recommend they go buy some plaster and start making their own.
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post #555 of 11387 Old 12-15-2010, 04:28 PM
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Originally Posted by noah katz View Post

I'm not sure, but I thought he scaled XO freq directly with woofer/WG size, which makes perfect sense technically.

Look at where the vertical nulls are in the Princeton directivity map of Nathan 10" - it's crossed down at 1 kHz, the forward axis is poorly aimed, and even crossed that low, the forward lobe is short. Earl says that's the "old" design Nathan; let's hope he fixed some of that in the revised version.

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Originally Posted by mjg100 View Post

Zilch, In your link (looking at the chart) I do not see a crossover for the 3012LF paired with the D220Ti. Which crossover should I be looking at?

I never ran that combo, but the files are there to put it together in PCD. It's SR, as I recall, used D220Ti on 152i, and Deluxe built with 3012LF. Deluxe uses a custom Schumacher design crossover which is not likely optimum for SR, so it's not mix and match, but the SR highpass should be close enough for that part to be a start.

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post #556 of 11387 Old 12-15-2010, 04:49 PM
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Originally Posted by ZilchLab View Post

Look at where the vertical nulls are in the Princeton directivity map of Nathan 10" - it's crossed down at 1 kHz, the forward axis is poorly aimed, and even crossed that low, the forward lobe is short. Earl says that's the "old" design Nathan; let's hope he fixed some of that in the revised version..

I have said this many times but you have to stop using the Nathan as the reference point. You use it because its the weakest of all Geddes designs. We should reference the Summa or abbey designs in these discussions, its unfair to throw all Geddes design theories, XO creation under the bus because of the cheapest speaker he builds.

We could take 10 low cost designs and poke holes in them but Im not sure what the point of that exercise is. No one is gauging Geddes designs skills based on the Nathan are they? Its like saying JBL is a crap company because of they make some really crappy speakers.

Even if he didnt fix it 99.9% of all listener will never know the difference. I own some Tannoy V8s, you should see their measurements (I have posted them in this forum). I have zero issues with them on the subjective side though.

Can we move beyond what amounts to you trying to convince people that Geddes isn't a good speaker designer? We get that you have a better speaker design, one that I will never ever copy...I will still copy Geddes first Its all just choice, your priorities are not written in stone for others to follow.

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post #557 of 11387 Old 12-15-2010, 04:58 PM
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Originally Posted by penngray View Post

I have said this many times but you have to stop using the Nathan as the reference point. You use it because its the weakest of all Geddes designs. We should reference the Summa or abbey designs in these discussions, its unfair to throw all Geddes design theories, XO creation under the bus because of the cheapest speaker he builds.

Harper 8" is his cheapest design, not Nathan.

Get some data on the others, and we'll discuss them.

[That ain't forthcoming from Earl, trust me on this.... ]


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Originally Posted by penngray View Post

Can we move beyond what amounts to you trying to convince people that Geddes isn't a good speaker designer? We get that you have a better speaker design, one that I will never ever copy...I will still copy Geddes first Its all just choice, your priorities are not written in stone for others to follow.

The writing's on the wall, and you and I agree with respect to what's up.

Somehow, however, it's a given good bet that EconoWave will abide....

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post #558 of 11387 Old 12-15-2010, 05:21 PM - Thread Starter
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maybe i can help...the poll was clear, surprisingly.

it seemed that what folks wanted was: 15" eos, ~90x45, 1" bolt on, appropriate roundover to allow the o.s. to hold directivity down to around 1khz, throat geometry to mate to de250 driver. there was some interest in having the oval mouth terminate to a rectangular baffle for easy mounting in a standard enclosure, but not increasing the overall height/width.

the idea was to capture many of the benefits inherent to the geddes design, but then improve it in two ways with the elliptical. first, would be better matching of the vertical nulls to woofer by reducing the center-to-center distance of the tweet and the woof. second, and perhaps more importantly would be to fix the on-axis hole in frequency response.

unless there is good reason to choose something else, why don't we lock in on this and move it forward?

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post #559 of 11387 Old 12-15-2010, 05:50 PM
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I'm sold. Eric H, do you want us to sign up to help fund the protos to be tested? I'd be willing to pitch in. $50 ea, or....suggest other?

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Originally Posted by LTD02 View Post

maybe i can help...the poll was clear, surprisingly.

it seemed that what folks wanted was: 15" eos, ~90x45, 1" bolt on, appropriate roundover to allow the o.s. to hold directivity down to around 1khz, throat geometry to mate to de250 driver. there was some interest in having the oval mouth terminate to a rectangular baffle for easy mounting in a standard enclosure, but not increasing the overall height/width.

the idea was to capture many of the benefits inherent to the geddes design, but then improve it in two ways with the elliptical. first, would be better matching of the vertical nulls to woofer by reducing the center-to-center distance of the tweet and the woof. second, and perhaps more importantly would be to fix the on-axis hole in frequency response.

unless there is good reason to choose something else, why don't we lock in on this and move it forward?


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post #560 of 11387 Old 12-15-2010, 05:51 PM
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Originally Posted by ZilchLab View Post

Harper 8" is his cheapest design, not Nathan.

Get some data on the others, and we'll discuss them.

[That ain't forthcoming from Earl, trust me on this.... ]

Okay, its the 2nd worst. Its still not the reference point we are talking about, the waveguide has to be 12" or greater for any discussion to matter.


Quote:


The writing's on the wall, and you and I agree with respect to what's up.

Somehow, however, it's a given good bet that EconoWave will abide....

Zilch we agree on a lot of things. We just choose different paths. No doubt the Econowave designs will be built and owned by more people. Never questioned that but it still stands as a simple fact I will be building a DIY clone of the Abbeys and the Summas for reasons you may not understand or want to understand. I was never concerned about your opinion on what we should build.

Should I know about other motives for your constant bashing of Geddes designs? Maybe Commercial interests? Or is just a simple support for Parham and his products, supporting them by bashing Geddes?

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post #561 of 11387 Old 12-15-2010, 05:55 PM
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Originally Posted by bwaslo View Post

I'm sold. Eric H, do you want us to sign up to help fund the protos to be tested? I'd be willing to pitch in. $50 ea, or....suggest other?

thanks BWaslo!! Eric H. Just tell us what you need to help you out.

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post #562 of 11387 Old 12-15-2010, 06:17 PM - Thread Starter
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things are *really* tight for me right now, so the best that i can do is $50 to advance the prototype. that's not for any horns, just for r&d, but i want "friend pricing" later on. ;-)

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post #563 of 11387 Old 12-15-2010, 06:20 PM
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Originally Posted by penngray View Post

Should I know about other motives for your constant bashing of Geddes designs? Maybe Commercial interests? Or is just a simple support for Parham and his products, supporting them by bashing Geddes?

Get OFF it, Penn.

I am a STUDENT of Geddes designs, and I posted my full view on him and his work above. That's possibly the best post I have ever written in my life on these matters:

http://www.avsforum.com/avs-vb/showt...7#post19648897

As a student, and within my own capabilities, I have studied his approach with a scrutinizing eye as to what he does and why, and have engaged in full discussions in on-line forums for years relative to these elements. That's the level of inquiry that's required to understand the basics, largely because he only dispenses what best serves his larger purpose, and it's necessary to read deeply between the lines to get it.

I don't know whit about the actual merits of OS vs. other profiles, whether HOMs exist beyond the hypothetical, or whether any of that carries the performance significance he would have everyone believe is attributable to them. Same deal with the foam plug.

FACT is, like me, you've never even heard a GedLee speaker, and certainly not in comparison to other "world class" designs. I do know others who have, however, and therefore believe there is substance worthy of pursuit here. I ALSO know that, despite his dismissal of most, indeed, nearly ALL of their defects and shortcomings, his designs are flawed in many respects. From that, we can move ahead and improve upon them and get closer to the truth during that process; it's clear he has little motivation to proceed aggressively in this direction himself at this point....

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post #564 of 11387 Old 12-15-2010, 06:22 PM
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Quote:
Originally Posted by LTD02 View Post

maybe i can help...the poll was clear, surprisingly.

it seemed that what folks wanted was: 15" eos, ~90x45, 1" bolt on, appropriate roundover to allow the o.s. to hold directivity down to around 1khz, throat geometry to mate to de250 driver. there was some interest in having the oval mouth terminate to a rectangular baffle for easy mounting in a standard enclosure, but not increasing the overall height/width.

the idea was to capture many of the benefits inherent to the geddes design, but then improve it in two ways with the elliptical. first, would be better matching of the vertical nulls to woofer by reducing the center-to-center distance of the tweet and the woof. second, and perhaps more importantly would be to fix the on-axis hole in frequency response.

unless there is good reason to choose something else, why don't we lock in on this and move it forward?

+1 on those specs for the group. My absolute ideal would be larger, but I know that very few others would want in on that. I'd still be thrilled with those specs and I'd buy some in the first batch. I might still try to make a larger version for myself, but that wouldn't be a production run of any sort.
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post #565 of 11387 Old 12-15-2010, 09:45 PM
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No need to help with any funding. I appreciate the offers, but I said I'd do what I can, and I certainly will push to get it done. Well, it will get done.

The main thing is to get the correct one built, and I think LTD02 pretty much answered my questions.

One quick thing though, many thought the SEOS would be better, and it's pretty darn close to the EOS anyway, so should we go that route? I might be a little harder to build, but if we're going to do it, shouldn't we hook up with the SEOS? Or does that design pose to many questions with performance?

AudioJosh said "I think the super ellipse will likely lessen the on axis dip versus round or even elipse. I think an N = 2.5 would be pretty ideal."

And I believe Zilch thought it was a good idea too. I don't recall that it changes the actual size enough to throw off the initial votes. So, I was just curious. I'll go back and read through more comments about it.
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post #566 of 11387 Old 12-15-2010, 10:41 PM - Thread Starter
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mighty kind of you erich to be both the banker and the design leader.

"One quick thing though, many thought the SEOS would be better, and it's pretty darn close to the EOS anyway, so should we go that route?

1. is there any data or theory to suggest that the seos is better than eos and for what reason?

guys, let's keep the conversation rifle shot on this question during the next couple of days and make a final decision on a way to proceed by then. cool?

current specs:

15" eos/seos, ~90x45, 1" bolt on, appropriate roundover to allow the o.s. to hold directivity down to around 1khz, throat geometry to mate to de250 driver. oval mouth terminates to a rectangular baffle for easy mounting in a standard enclosure, but not increasing the overall height/width.

the idea is to capture many of the benefits inherent to the geddes design, but then improve it in two ways with the elliptical. first, would be better matching of the vertical nulls to woofer by reducing the center-to-center distance of the tweet and the woof. second, and perhaps more importantly would be to fix the on-axis hole in frequency response.

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post #567 of 11387 Old 12-15-2010, 10:47 PM - Thread Starter
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i know it is oddball to reply to my own post, but i am just one vote among all of yours, so this is my vote. in my estimation, if this waveguide is done properly, eos vs. seos won't matter. either one is fine to me.

Quote:
Originally Posted by LTD02 View Post

mighty kind of you erich to be both the banker and the design leader.

"One quick thing though, many thought the SEOS would be better, and it's pretty darn close to the EOS anyway, so should we go that route?

1. is there any data or theory to suggest that the seos is better than eos and for what reason?

guys, let's keep the conversation rifle shot on this question during the next couple of days and make a final decision on a way to proceed by then. cool?

current specs:

15" eos/seos, ~90x45, 1" bolt on, appropriate roundover to allow the o.s. to hold directivity down to around 1khz, throat geometry to mate to de250 driver. oval mouth terminates to a rectangular baffle for easy mounting in a standard enclosure, but not increasing the overall height/width.

the idea is to capture many of the benefits inherent to the geddes design, but then improve it in two ways with the elliptical. first, would be better matching of the vertical nulls to woofer by reducing the center-to-center distance of the tweet and the woof. second, and perhaps more importantly would be to fix the on-axis hole in frequency response.


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post #568 of 11387 Old 12-16-2010, 12:30 AM
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Quote:
Originally Posted by coctostan View Post

+1 on those specs for the group. My absolute ideal would be larger, but I know that very few others would want in on that. I'd still be thrilled with those specs and I'd buy some in the first batch. I might still try to make a larger version for myself, but that wouldn't be a production run of any sort.

I agree, I would love to see what happens with this batch, but I would not mind a larger sized one myself.

Quote:
Originally Posted by Erich H View Post

One quick thing though, many thought the SEOS would be better, and it's pretty darn close to the EOS anyway, so should we go that route? I might be a little harder to build, but if we're going to do it, shouldn't we hook up with the SEOS? Or does that design pose to many questions with performance?

AudioJosh said "I think the super ellipse will likely lessen the on axis dip versus round or even elipse. I think an N = 2.5 would be pretty ideal."

And I believe Zilch thought it was a good idea too. I don't recall that it changes the actual size enough to throw off the initial votes. So, I was just curious. I'll go back and read through more comments about it.

Which ever one looks like it would end up the better end product. We are in this to build the best we possibly can.

Quote:
Originally Posted by LTD02 View Post

"One quick thing though, many thought the SEOS would be better, and it's pretty darn close to the EOS anyway, so should we go that route?

1. is there any data or theory to suggest that the seos is better than eos and for what reason?

guys, let's keep the conversation rifle shot on this question during the next couple of days and make a final decision on a way to proceed by then. cool?

current specs:

15" eos/seos, ~90x45, 1" bolt on, appropriate roundover to allow the o.s. to hold directivity down to around 1khz, throat geometry to mate to de250 driver. oval mouth terminates to a rectangular baffle for easy mounting in a standard enclosure, but not increasing the overall height/width.

the idea is to capture many of the benefits inherent to the geddes design, but then improve it in two ways with the elliptical. first, would be better matching of the vertical nulls to woofer by reducing the center-to-center distance of the tweet and the woof. second, and perhaps more importantly would be to fix the on-axis hole in frequency response.

+1 I agree with these so far as the base specs, though if we find out SEOS versus EOS is better then why not.
Though Without testing I would not know which would would be a better overall performer, unless we have some data on that and can end the EOS/SEOS debate.

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post #569 of 11387 Old 12-16-2010, 05:23 AM
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Seems like no one cares too much between EOS or SEOS. Since Erich H is taking the lead on this effort, why don't we just leave it to him whether to go with EOS or SEOS? That way, if the SEOS turns out to be too difficult, he can step back to EOS without needing further discussion.

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post #570 of 11387 Old 12-16-2010, 06:13 AM
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Quote:
Originally Posted by LTD02 View Post

1. is there any data or theory to suggest that the seos is better than eos and for what reason?

Just theory. If the costs are similar then there is no downside to going with the SEOS, it seems to have a little more interest too.

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