***DIY Dayton Pics. 80 Pictures**** *PIC*

[chrism]

http://i13.photobucket.com/albums/a300/reelaudiophile/DIY%20DAYTON%202005/100_0075.jpg


Posted below is a link to the pics I took of DIY Dayton. There are a few projects that are unidentified. Please forgive me for forgetting to whom they belonged to. If someone knows, please let me know so I can fix the picture tags.

All in all, I had a very good time. There were many excellent projects. Some that come to mind were Jim Griffin's arrays. His hotel room looked like NASA with all of the equipment he brought along. Darren had an unplayed set of arrays he brought that once dialed in by Christian were awesome. Paul K had a very nice set of 3 ways. These were one of my personal favorites. The "Olives" were the most visually interesting and unconventional project IMHO. There were no bad or even marginal projects this year.

Matt Olsen brought 2 sets of DIY amps. Ed brought a very nice DIY amp also. I think a DIY amp is now in my future.

I had the privelege of getting to do Pjay's normal job of MC'ing the event. We used a test disk Jim Griffin brought back from the Rocky Mountain Audio Fest as well as a disk brought by Matt Olsen.

I saw many familiar as well as a few new faces this year. The Noid made a cameo appearance. Hopefully he will have an opportunity to return next year. I hope to see many more people next year. For those of you who normally attend and didn't, I would have to say that you missed out on some great projects and wonderful discussions.

My wife Connie was the only female to attend this year. Everyone should be encouraged to bring their spouses next year. She actually asked me to build Jim Griffin's bipole full range project after hearing them. DIY Dayton definitely helped my SAF of speakerbuilding. Could it help you to be able to build bigger and better projects and stay out of the dog house? I bet it could. She didn't even flinch when we went over to PE for our shopping trip. She says she will submit a project next year. Everyone should look out because she is one heck of an artist and woodworker and will likely come up with something very different and awesome looking.

All in all, it was a great couple of days. PE was a gracious host. Hopefully, they will keep on hosting this event.

[chrism]

Provided Link: DIY Dayton Pics (http://photobucket.com/albums/a300/reelaudiophile/DIY%20DAYTON%202005/)


Here is the link. Sorry about that.

[jdm]

> Posted below is a link to the pics I took of
> DIY Dayton. There are a few projects that
> are unidentified. Please forgive me for
> forgetting to whom they belonged to. If
> someone knows, please let me know so I can
> fix the picture tags.

> All in all, I had a very good time. There
> were many excellent projects. Some that come
> to mind were Jim Griffin's arrays. His hotel
> room looked like NASA with all of the
> equipment he brought along. Darren had an
> unplayed set of arrays he brought that once
> dialed in by Christian were awesome. Paul K
> had a very nice set of 3 ways. These were
> one of my personal favorites. The
> "Olives" were the most visually
> interesting and unconventional project IMHO.
> There were no bad or even marginal projects
> this year.

> Matt Olsen brought 2 sets of DIY amps. Ed
> brought a very nice DIY amp also. I think a
> DIY amp is now in my future.

> I had the privelege of getting to do Pjay's
> normal job of MC'ing the event. We used a
> test disk Jim Griffin brought back from the
> Rocky Mountain Audio Fest as well as a disk
> brought by Matt Olsen.

> I saw many familiar as well as a few new
> faces this year. The Noid made a cameo
> appearance. Hopefully he will have an
> opportunity to return next year. I hope to
> see many more people next year. For those of
> you who normally attend and didn't, I would
> have to say that you missed out on some
> great projects and wonderful discussions.

> My wife Connie was the only female to attend
> this year. Everyone should be encouraged to
> bring their spouses next year. She actually
> asked me to build Jim Griffin's bipole full
> range project after hearing them. DIY Dayton
> definitely helped my SAF of speakerbuilding.
> Could it help you to be able to build bigger
> and better projects and stay out of the dog
> house? I bet it could. She didn't even
> flinch when we went over to PE for our
> shopping trip. She says she will submit a
> project next year. Everyone should look out
> because she is one heck of an artist and
> woodworker and will likely come up with
> something very different and awesome
> looking.

> All in all, it was a great couple of days.
> PE was a gracious host. Hopefully, they will
> keep on hosting this event.

Hi nice job takeing pics. I was looking at a

speaker and wanted to know waht kind of

fullrange it was and, how it sounded? It is on

the first page called Olive anyone? It is a

green round shape with a driver with a red dust

cap. Cool but, creepy looking.Thanks jm

[chadg]

Provided Link: Olive Project (http://chadgray.info/projectdetail.cfm?ProjectID=48)


Hehe, cool, but creepy. I wondered if it would come across as creepy to some. When i first started the project a lot of people wanted me to paint them up like eye *****.

I need to find a source for RED grill fabric so i dont have to paint the driver.

Here is a link to the project. Right now i just have pages and pictures of the build. I will get more details on the actual box, driver etc this week.

In a nut shell:
Full Range Drivers: TB 881, Sealed box 1.7 liters
Sub: 5.25" Dayton Classic in 22 liter ported box, Keiga 2.1 media amplifier.

[rudy]

[Paul K.]

Great picture Chris and you did a bang-up job as emcee. Thanks, also, for the nice comments on my speakers, the TriLangles.
Paul K.

> Posted below is a link to the pics I took of
> DIY Dayton. There are a few projects that
> are unidentified. Please forgive me for
> forgetting to whom they belonged to. If
> someone knows, please let me know so I can
> fix the picture tags.

> All in all, I had a very good time. There
> were many excellent projects. Some that come
> to mind were Jim Griffin's arrays. His hotel
> room looked like NASA with all of the
> equipment he brought along. Darren had an
> unplayed set of arrays he brought that once
> dialed in by Christian were awesome. Paul K
> had a very nice set of 3 ways. These were
> one of my personal favorites. The
> "Olives" were the most visually
> interesting and unconventional project IMHO.
> There were no bad or even marginal projects
> this year.

> Matt Olsen brought 2 sets of DIY amps. Ed
> brought a very nice DIY amp also. I think a
> DIY amp is now in my future.

> I had the privelege of getting to do Pjay's
> normal job of MC'ing the event. We used a
> test disk Jim Griffin brought back from the
> Rocky Mountain Audio Fest as well as a disk
> brought by Matt Olsen.

> I saw many familiar as well as a few new
> faces this year. The Noid made a cameo
> appearance. Hopefully he will have an
> opportunity to return next year. I hope to
> see many more people next year. For those of
> you who normally attend and didn't, I would
> have to say that you missed out on some
> great projects and wonderful discussions.

> My wife Connie was the only female to attend
> this year. Everyone should be encouraged to
> bring their spouses next year. She actually
> asked me to build Jim Griffin's bipole full
> range project after hearing them. DIY Dayton
> definitely helped my SAF of speakerbuilding.
> Could it help you to be able to build bigger
> and better projects and stay out of the dog
> house? I bet it could. She didn't even
> flinch when we went over to PE for our
> shopping trip. She says she will submit a
> project next year. Everyone should look out
> because she is one heck of an artist and
> woodworker and will likely come up with
> something very different and awesome
> looking.

> All in all, it was a great couple of days.
> PE was a gracious host. Hopefully, they will
> keep on hosting this event.

[edlafontaine]

Several people asked about the amp I brought. The following link will give the rest of the story:

<A HREF="http://www.diyaudio.com/forums/showthread.php?s=&postid=740086#post740086">http://www.diyaudio.com/forums/showthread.php?s=&postid=740086#post740086</A>

As I requested at the show, please give me your comments and critiques. It's how things improve!

[Wolf]

We set off a car alarm 3 times from ACROSS the parking lot! Running off Darren's Blau T-amp, we were throbbing. I was grinning ear-ear. Just an experience. Single 18" Omega Pro.
Later,
Wolf

[jasonb]

Provided Link: http://www.cardomain.com/shoplist~b~R/T~t~Speaker+Grille+Cloths


Hope this helps. Very cool design by the way, the martini glass stands are perfect!

Jason

> Hehe, cool, but creepy. I wondered if it
> would come across as creepy to some. When i
> first started the project a lot of people
> wanted me to paint them up like eye *****.

> I need to find a source for RED grill fabric
> so i dont have to paint the driver.

> Here is a link to the project. Right now i
> just have pages and pictures of the build. I
> will get more details on the actual box,
> driver etc this week.

> In a nut shell:
> Full Range Drivers: TB 881, Sealed box 1.7
> liters
> Sub: 5.25" Dayton Classic in 22 liter
> ported box, Keiga 2.1 media amplifier.

[dylanmatlow]

My full range was Zaph's B3s design -- just with an extra cap across the baffle step... can't remember it was between 1-2uF to help bring up the upper end off axis :)

Whos design was that little 5" 2 way -- it was awesome and can fit almost anywhere!!! I want to build one :)

> Posted below is a link to the pics I took of
> DIY Dayton. There are a few projects that
> are unidentified. Please forgive me for
> forgetting to whom they belonged to. If
> someone knows, please let me know so I can
> fix the picture tags.

> All in all, I had a very good time. There
> were many excellent projects. Some that come
> to mind were Jim Griffin's arrays. His hotel
> room looked like NASA with all of the
> equipment he brought along. Darren had an
> unplayed set of arrays he brought that once
> dialed in by Christian were awesome. Paul K
> had a very nice set of 3 ways. These were
> one of my personal favorites. The
> "Olives" were the most visually
> interesting and unconventional project IMHO.
> There were no bad or even marginal projects
> this year.

> Matt Olsen brought 2 sets of DIY amps. Ed
> brought a very nice DIY amp also. I think a
> DIY amp is now in my future.

> I had the privelege of getting to do Pjay's
> normal job of MC'ing the event. We used a
> test disk Jim Griffin brought back from the
> Rocky Mountain Audio Fest as well as a disk
> brought by Matt Olsen.

> I saw many familiar as well as a few new
> faces this year. The Noid made a cameo
> appearance. Hopefully he will have an
> opportunity to return next year. I hope to
> see many more people next year. For those of
> you who normally attend and didn't, I would
> have to say that you missed out on some
> great projects and wonderful discussions.

> My wife Connie was the only female to attend
> this year. Everyone should be encouraged to
> bring their spouses next year. She actually
> asked me to build Jim Griffin's bipole full
> range project after hearing them. DIY Dayton
> definitely helped my SAF of speakerbuilding.
> Could it help you to be able to build bigger
> and better projects and stay out of the dog
> house? I bet it could. She didn't even
> flinch when we went over to PE for our
> shopping trip. She says she will submit a
> project next year. Everyone should look out
> because she is one heck of an artist and
> woodworker and will likely come up with
> something very different and awesome
> looking.

> All in all, it was a great couple of days.
> PE was a gracious host. Hopefully, they will
> keep on hosting this event.

[romanbednarek]

http://www.rjbaudio.com/Bandit/Bandit%20angled.jpg

Provided Link: Bandit (http://www.rjbaudio.com/Bandit/bandit.html)


> My full range was Zaph's B3s design -- just
> with an extra cap across the baffle step...
> can't remember it was between 1-2uF to help
> bring up the upper end off axis :)

> Whos design was that little 5" 2 way --
> it was awesome and can fit almost
> anywhere!!! I want to build one :)

I'm curious to know what you think of the B3S fullrange design. I just completed my Tang Band W4-1320SB design and am very happy with it except for one thing, the off axis high end response isn't very good. How is the off axis performance of your design? I noticed that metal cones tend to have better off axis response than paper/poly and the smaller cone (3" instead of 4") should help as well but I'm just wondering how much better it might be. Mine are only good within a 15 degree window, outside of that the highs start to disappear.

[chadg]

Provided Link: http://chadgray.info/


Awe... i missed it! At least it got fired up!

Did it need much power?

[dylanmatlow]

I think they do pretty well off axis now with the cap defeating the baffle step at higher freq... Right on axis they are a little extra airy which I kinda like but they sound acceptable to about 30 degrees off axis... The Mfr's response plots show the top end above 10k drooping anyways even if zaph's measurements didn't... but my ears liked the cap :)

They are about 2.5 ft in front of me toed in not at my head, but a little more. If I stand up they still sound fine... The frequency response is no longer exceedingly flat... but still sounds much better than some little $9 drivers have a right to...

What gets me is the very low efficiency... in a 5.1 system in a small-medium room with an appropriate highpass they still get plenty loud. Even without a highpass at the DIY event they got to an almost casual listening level :) – I hope someone else will comment…

> I'm curious to know what you think of the
> B3S fullrange design. I just completed my
> Tang Band W4-1320SB design and am very happy
> with it except for one thing, the off axis
> high end response isn't very good. How is
> the off axis performance of your design? I
> noticed that metal cones tend to have better
> off axis response than paper/poly and the
> smaller cone (3" instead of 4")
> should help as well but I'm just wondering
> how much better it might be. Mine are only
> good within a 15 degree window, outside of
> that the highs start to disappear.

[chadg]

Provided Link: http://chadgray.info


Hi Roman, I would try making your baffle larger to help with the high end off axis. Just for a test throw some scrap pieces of MDF on one or both sides of your front baffle. I think that narrow width and centered driver is the root of your problem.

[chadg]

Provided Link: http://chadgray.info/


Thanks for the link Jason! It will come in handy for the re-design.

[romanbednarek]

Provided Link: RJB Audio Projects (http://www.rjbaudio.com)


> Hi Roman, I would try making your baffle
> larger to help with the high end off axis.
> Just for a test throw some scrap pieces of
> MDF on one or both sides of your front
> baffle. I think that narrow width and
> centered driver is the root of your problem.

Thanks for the suggestion but I disagree with your assessment. I think it is purely a function of the cone size and cone material. I took measurements of the response off axis in both the vertical (where the cabinet is 15" long) and horizontal (where the cabinet is 7" wide) directions and there is hardly any difference in the top end response. The measurements are posted on my site.

I did some research and determined that paper cone fullrange drivers tend to have worse dispersion compared to metal cone drivers for some reason and the larger 4" cone doesn't help either. I don't think there is anything I can do about it without adding a tweeter which I don't want to do so I guess these speakers will require you to stay in the "sweet spot" for the best sound and that is fine for my current application.

[romanbednarek]

> I think they do pretty well off axis now
> with the cap defeating the baffle step at
> higher freq... Right on axis they are a
> little extra airy which I kinda like but
> they sound acceptable to about 30 degrees
> off axis... The Mfr's response plots show
> the top end above 10k drooping anyways even
> if zaph's measurements didn't... but my ears
> liked the cap :)

> They are about 2.5 ft in front of me toed in
> not at my head, but a little more. If I
> stand up they still sound fine... The
> frequency response is no longer exceedingly
> flat... but still sounds much better than
> some little $9 drivers have a right to...

> What gets me is the very low efficiency...
> in a 5.1 system in a small-medium room with
> an appropriate highpass they still get
> plenty loud. Even without a highpass at the
> DIY event they got to an almost casual
> listening level :) – I hope someone else
> will comment…

Yeah, I noticed that Zaph's high frequency response looked a lot better than PE's posted measurements. You're probably getting about twice as good off axis performance as me (30 degrees instead of 15 degrees where the highs begin disappearing) due to the smaller metal cone.

My design has decent efficiency at around 86 dB and they can play plent loud, that's for sure. My hearing threshold gives out before the drivers do but I don't like to listen to anything above 90 dB in my listening position. The bass response is decent for this little driver too.

Thanks for the information.

[chadg]

Provided Link: http://chadgray.info/


Just give it a shot out of curiosity. Dont center the driver. Add a little baffle on one of the short sides. See if it helps the off axis.

I mean there is not much to gain by off-setting the "tweeter" on the baffle but it might help.

[ajinfla]

> Just give it a shot out of curiosity. Dont
> center the driver. Add a little baffle on
> one of the short sides. See if it helps the
> off axis.

> I mean there is not much to gain by
> off-setting the "tweeter" on the
> baffle but it might help.

No. At (high) frequencies where the driver starts to beam, it is no longer illuminating the baffle. Basically, it no longer "sees" a baffle. Changing the shape will have no effect. I think you have that confused with lower treble/mid frequencies where the driver DOES illuminate the baffle. There will definately be an effect due to baffle shape at those frequencies.
As Roman stated, the primary reason for falling off axis is the size of the drivers cone. It has become acoustically too large to produce very high frequencies. The other reasons are the material and shape of the diaphram.
A 4" driver will beam. 'Tis the fallacy of a "Fullrange" single driver. There is no such thing. Only "extended" range drivers. That said, I'm a big coaxial fan :-).

Cheers,

AJ

[chadg]

Provided Link: http://chadgray.info/


You are right AJ and Roman. The baffle has no effect on the high end.

[romanbednarek]

> Just give it a shot out of curiosity. Dont
> center the driver. Add a little baffle on
> one of the short sides. See if it helps the
> off axis.

> I mean there is not much to gain by
> off-setting the "tweeter" on the
> baffle but it might help.

I have my center channel speaker on top of a VCR and TV that effectively extends the baffle on one side. Instead of dragging out all of my measurement equipment and measuring the response that way I used my RS SPL meter to determine what angle the response began to fade by playing a 10 kHz test tone. Based on my readings the response begins to drop as you get more than 15 degrees off axis regardless of which direction you move which coincides with my earlier free-field measurements of the original cabinet. I know that this isn't the most accurate way to measure but I think it still gives meaningful results.

Do you have any scientific basis for your concept that extending the baffle will improve the high frequency off axis performance? Based on my somewhat limited knowledge I don't understand how it would because the wavelengths are so short at those high frequencies, much shorter than even the shortest baffle dimension of my cabinet. Also, baffle diffraction simulations reveal that baffle effects occur lower in frequencies due to the baffle size and wavelength relationship. I could possibly see where not flush mounting a driver (especially a tweeter) could have an influence on the response in this region but not extending a baffle that is only influencing relatively lower frequencies. Offsetting a tweeter on a baffle actually does make a difference in the lower tweeter frequencies (I wrote an article on my website about this).

Sorry to dispute your suggestion but it just doesn't make sense to me based on my experience. I could be wrong though because I'm always learning new things thanks to these discussion boards but I would like to know if you have any scientific theory behind your assumption.

[chadg]

Provided Link: http://chadgray.info/


It was all gut reaction not based on any science. Thanks for trying it though. Once i started thinking about i did come to the same conclusion that the baffle will not effect the high end.

This is probably for another thread, but how far can we take this? Is it true that even on an infinite baffle the high end is the high end determined by the shape and characteristics of the driver making the frequencies.

just being curious.

[shawn_a]

I know that they were just amazing speakers to say the very least. There should be a law against small woofers making that much bass. I will be happy to break that law time and again with pleasure. Hats off to Dave and Roman for some excellent design and execution. I'm building some too.

shawn

[shawn_a]

> Awe... i missed it! At least it got fired
> up!

> Did it need much power?

Yes, it was great to finally fire it up. It would have been plain wrong not to do it. We started with my Soundstream Lil Wonder amp and it was doing some decent things. After Darren pulled up and we hooked up some more juice, things got interesting. Really interesting. I would guess that it was a good 150 feet to Christian's car whose alarm we were setting off. I think it's safe to assume Bobby got it done pretty well. He built it just to see if he could. I consider it mission accomplished.

shawn

[romanbednarek]

> It was all gut reaction not based on any
> science. Thanks for trying it though. Once i
> started thinking about i did come to the
> same conclusion that the baffle will not
> effect the high end.

> This is probably for another thread, but how
> far can we take this? Is it true that even
> on an infinite baffle the high end is the
> high end determined by the shape and
> characteristics of the driver making the
> frequencies.

> just being curious.

I apologize for hijacking this thread but I have a new fascination with fullrange designs and am trying to learn more about what affects the high frequency off axis performance.

I still have a lot to learn in this area but I believe that there are a couple of major factors that determine how well a driver will perform off axis at high frequencies. One of them is the size of the cone and I'm not sure if I have the details figured out just yet. I think that when the wavelength of the sound gets shorter than the driver diameter the frequencies begin to cancel off axis in the same way that comb filtering works between two identical drivers. Now this is where my knowledge really falls short but I think that the frequencies radiating from the cone cancel with each other because they are out of phase with each other as you move to one side of the driver. I've read that lower frequencies tend to eminate from the outside of the driver and higher frequencies tend to come from the center but I need to learn more about this as well.

Another interesting topic is cone geometry and cone material. I've heard the phrase "pistonic behavior" used before to describe the acoustical physics behind the driver operation but also need to learn more about this as well. It appears that metal cones tend to have a true pistonic behavior that extends higher in frequency than softer cone materials due to the cone stiffness. As a result the off axis high frequency dispersion is better. So I think the Tang Band W4-1320SB that I'm using is suffering from two shortcomings... a flexible paper/bamboo cone and a relatively large cone diameter.

If anybody knows of any sources of information regarding these topics please let me know because I would like to learn some more. If not then maybe we can start a new thread and some of the experts can fill us in. Thanks.

[dylanmatlow]

> I apologize for hijacking this thread but I
> have a new fascination with fullrange
> designs and am trying to learn more about
> what affects the high frequency off axis
> performance.

> I still have a lot to learn in this area but
> I believe that there are a couple of major
> factors that determine how well a driver
> will perform off axis at high frequencies.
> One of them is the size of the cone and I'm
> not sure if I have the details figured out
> just yet. I think that when the wavelength
> of the sound gets shorter than the driver
> diameter the frequencies begin to cancel off
> axis in the same way that comb filtering
> works between two identical drivers. Now
> this is where my knowledge really falls
> short but I think that the frequencies
> radiating from the cone cancel with each
> other because they are out of phase with
> each other as you move to one side of the
> driver. I've read that lower frequencies
> tend to eminate from the outside of the
> driver and higher frequencies tend to come
> from the center but I need to learn more
> about this as well.

> Another interesting topic is cone geometry
> and cone material. I've heard the phrase
> "pistonic behavior" used before to
> describe the acoustical physics behind the
> driver operation but also need to learn more
> about this as well. It appears that metal
> cones tend to have a true pistonic behavior
> that extends higher in frequency than softer
> cone materials due to the cone stiffness. As
> a result the off axis high frequency
> dispersion is better. So I think the Tang
> Band W4-1320SB that I'm using is suffering
> from two shortcomings... a flexible
> paper/bamboo cone and a relatively large
> cone diameter.

> If anybody knows of any sources of
> information regarding these topics please
> let me know because I would like to learn
> some more. If not then maybe we can start a
> new thread and some of the experts can fill
> us in. Thanks.

trends off axis are just due to point source diffraction patterns??? I would assume? relative to wavelength? so your ideal is a very thin, narrow ribbon that stretches from the floor to the roof?

My question is about breakup modes... Related to the speed of sound in the material and the diameter of the cone??? Anyone have an aswer to where breakup modes peak their ugly heads?

[dylanmatlow]

> I know that they were just amazing speakers
> to say the very least. There should be a law
> against small woofers making that much bass.
> I will be happy to break that law time and
> again with pleasure. Hats off to Dave and
> Roman for some excellent design and
> execution. I'm building some too.

> shawn
Any chance I can grab a link to this design? :)

[romanbednarek]

> trends off axis are just due to point source
> diffraction patterns??? I would assume?
> relative to wavelength? so your ideal is a
> very thin, narrow ribbon that stretches from
> the floor to the roof?

Yeah, that would probably have very good dispersion horizontally.

> My question is about breakup modes...
> Related to the speed of sound in the
> material and the diameter of the cone???
> Anyone have an aswer to where breakup modes
> peak their ugly heads?

I did some research and came up with a couple of sites that discuss this topic. Rather than try to repeat what they said I'll let you read them yourself. The sites are...

<A HREF="http://www.cosmos2000.org/audio/lspeaker.htm">http://www.cosmos2000.org/audio/lspeaker.htm</A>

and this second one talks about cone geometry...

<A HREF="http://www.loudsoft.com/my_documents/my_files/ALMA">http://www.loudsoft.com/my_documents/my_files/ALMA</A>%20Paper%202003.pdf

(you'll probably have to copy & paste the second link to get it to work)

Hope that helps.

[romanbednarek]

http://www.rjbaudio.com/misc/Microbe%20RS.JPG

Provided Link: RJB Audio Projects (http://www.rjbaudio.com)


> Any chance I can grab a link to this design?
> :)

I don't have the exact cabinet details but I think it uses a cabinet the same size as my Microbe design that is listed under the projects section. I don't recall the exact driver locations on the baffle offhand though.

However, I do have the crossover design that I came up with a while back. It uses a 15 gauge air core inductor for the woofer filter and an 18 gauge air core for the notch filter. A small gauge inductor should be used for the 0.22 mH inductor or else the peak at 3.5kHz gets a bit larger.

Dave Zachary can probably fill you in on the details of what components he used in his filter as well as the enclosure details and driver locations.

Hope that helps.

[dzach]

Thank Roman.

There is no link out there to grab the whole design, but I owe Noid a design write up for these (they are his raffle tweeters in there!) so I have been meaning to pull together the details.

Hopefully later this evening or tomorrow...

gotta run catch a plane to Chicago...
dzach

> I don't have the exact cabinet details but I
> think it uses a cabinet the same size as my
> Microbe design that is listed under the
> projects section. I don't recall the exact
> driver locations on the baffle offhand
> though.

> However, I do have the crossover design that
> I came up with a while back. It uses a 15
> gauge air core inductor for the woofer
> filter and an 18 gauge air core for the
> notch filter. A small gauge inductor should
> be used for the 0.22 mH inductor or else the
> peak at 3.5kHz gets a bit larger.

> Dave Zachary can probably fill you in on the
> details of what components he used in his
> filter as well as the enclosure details and
> driver locations.

> Hope that helps.

[mgh]

Look at Dan Russell's page. Here's a link for a "simple model" of a speaker cone:

<A HREF="http://www.kettering.edu/~drussell/Demos/BaffledPiston/BaffledPiston.html">http://www.kettering.edu/~drussell/Demos/BaffledPiston/BaffledPiston.html</A>

Murray

> I apologize for hijacking this thread but I
> have a new fascination with fullrange
> designs and am trying to learn more about
> what affects the high frequency off axis
> performance.

> I still have a lot to learn in this area but
> I believe that there are a couple of major
> factors that determine how well a driver
> will perform off axis at high frequencies.
> One of them is the size of the cone and I'm
> not sure if I have the details figured out
> just yet. I think that when the wavelength
> of the sound gets shorter than the driver
> diameter the frequencies begin to cancel off
> axis in the same way that comb filtering
> works between two identical drivers. Now
> this is where my knowledge really falls
> short but I think that the frequencies
> radiating from the cone cancel with each
> other because they are out of phase with
> each other as you move to one side of the
> driver. I've read that lower frequencies
> tend to eminate from the outside of the
> driver and higher frequencies tend to come
> from the center but I need to learn more
> about this as well.

> Another interesting topic is cone geometry
> and cone material. I've heard the phrase
> "pistonic behavior" used before to
> describe the acoustical physics behind the
> driver operation but also need to learn more
> about this as well. It appears that metal
> cones tend to have a true pistonic behavior
> that extends higher in frequency than softer
> cone materials due to the cone stiffness. As
> a result the off axis high frequency
> dispersion is better. So I think the Tang
> Band W4-1320SB that I'm using is suffering
> from two shortcomings... a flexible
> paper/bamboo cone and a relatively large
> cone diameter.

> If anybody knows of any sources of
> information regarding these topics please
> let me know because I would like to learn
> some more. If not then maybe we can start a
> new thread and some of the experts can fill
> us in. Thanks.

[matthewkolson]

> Thank Roman.

> There is no link out there to grab the whole
> design, but I owe Noid a design write up for
> these (they are his raffle tweeters in
> there!) so I have been meaning to pull
> together the details.

> Hopefully later this evening or tomorrow...

> gotta run catch a plane to Chicago...
> dzach

Well done dave...well done. Those rocked.

now catch that plane!

-Matthew K. Olson

[romanbednarek]

> Thank Roman.

> There is no link out there to grab the whole
> design, but I owe Noid a design write up for
> these (they are his raffle tweeters in
> there!) so I have been meaning to pull
> together the details.

> Hopefully later this evening or tomorrow...

> gotta run catch a plane to Chicago...
> dzach

Dave, would you mind if I added your project to my website as an alternative to my Microbe project? I usually don't post projects that I haven't measured or listened to but since it keeps getting such great reviews I might be able to let this one slide. I should be able to take your information and generate a writeup on the project but might ask for more info if required. I'm still very happy that this design worked out so well for you. I've been tempted to build it myself just to see if the extra $60 in tweeter costs relative to the Microbe make that much of a difference. There are advantages to each design other than the tweeter quality (the RS28 version has a lower crossover point with better resonance mode rejection and the TB T25 version has slightly better high frequency extension and off axis performance). So let me know what you think of this idea when you get a chance.

[romanbednarek]

> Look at Dan Russell's page. Here's a link
> for a "simple model" of a speaker
> cone:

>
> <A HREF="http://www.kettering.edu/~drussell/Demos/BaffledPiston/BaffledPiston.html">http://www.kettering.edu/~drussell/Demos/BaffledPiston/BaffledPiston.html</A>
> Murray

Thanks for the link. I checked it out and it is very informative but it doesn't go into the details of why the dispersion suffers at higher frequencies. However, I've already figured that out from other sources (with larger diameter drivers at high frequencies the sound radiating from one side of the cone cancels with the sound from the other side when the distance between the radiating points approaches a half wavelength where they are 180 degrees out of phase).

If anyone knows of any other sources for information like this please let me know. Thanks.