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A 3 way 99db multi configurable SEOS design

355K views 4K replies 325 participants last post by  A9X-308 
#1 · (Edited)
The tux10-99
I'm pretty excited to announce I'm finally finished with the speaker in my avatar. It's been a long time coming. The first it was concieved was a post by maxmercy well over a year ago, so thanks for the idea Max.

It uses two Eminence 16ohm woofers, a pair of Celtion mids, and the SEOS10 with the DNA-205 compression driver. It`s 12" wide and final height about 40", maybe shorter depending on ports. Makes about 99db/w/m.

This speaker is configurable for tower or horizontal center. Like this:





and

and



I ended up preferring a WTMW layout. Also, the final version should have the woofers spaced closer to the mids and slightly shorter ports. I even plan to make a TMW version with the 8ohm woofer. Should only sacrifice a couple db doing that and save some height.

Here's an on axis FR with the ground plane spliced in. Sorta representative of what you'd get near a TV. This speaker is somewhat difficult to measure.



Yes, it does slope down like that. It sounds very good like this. Not bloated. Very dynamic and powerful sounding. It's hard to measure this speaker free space as the microphone is closer to the mids and tweeter, unless I back up to about 3m then reflections get in. So I measured GP and free field and combined them.

Here's a free space response, gated around 180hz so not that useful below 500hz where the gating starts to taper off the impulse response.



Here's the final impedance



I'd call this a 6ohm speaker. Still very easy to drive for most any receiver.

Here is a polar response of the tweeter/mid XO region and up.



You can see it's a little hot around 2500hz (orange). Room eq there would be ok.

Ok, now for the hard bit to explain. It seems people keep getting confused what this chart actually means, probably because you rarely see them. I definitely need to explain this a bit. Here's the side by side woofer portion FOR THE CENTER CONFIGURATION. If you are using vertical speakers, ignore this chart, it does not apply.



This chart shows the general woofer to mid XO region FOR THE HORIZONTAL CENTER ONLY!!!

Now, first off note that there's about a 40 degree listening window there. So that's pretty good. I think that works for most people. Second note that with most center channels, side wall reflections are far away. Also note, you never see a polar like this for a center channel MTM speaker. Because frankly, they're very very very bad, all the time. By comparison, this is really good and part of why I'm presenting the data this way. It's the easiest way to see nulls. Ok there's a few things going for us.

What's bad about it, well, there's some pretty deep nulls around 45 degrees. I've proposed to get them out closer to 60 degrees by moving the woofers closer to the mids. Originally I planned about a 500 or 600hz cross over. In the end there was a lot of overlap in the XO and it was around 750hz. This was done for power handling, bandpass gain, and lower/cheaper XO parts count. So in my plan, I spaced the woofers apart a little more than needed to make constructability easier and hoping to match directivity better. With the finished product, the woofers will be as tight as possible, so this should improve.

This is the XO to use. There are some floating around with mistakes. If you buy the kit, use this XO.



The mids are not available unless you buy the kit. The ferrite version on PE has not been tested. Also the 4ohm version will not work.

I'd appreciate any feedback or questions about the design. Thanks.

-------------------------------

Modifications

After more feedback on this design, I've provided some tweeter level and tuning options that can be found here: http://www.avsforum.com/forum/155-d...configurable-seos-design-40.html#post25958610

--------------------------------

FAQ

There's been a ton of questions about this design which have been repeated in this thread. I'm going to try and include them here for people to easily find.

Q. Why did you do this?
A. Because it's fun. Seriously.

Q. Is this design not good for people with AT screens? Was it developed just for people without AT screens?
A. No. It's a great design for AT screens. Erich and I just wanted something people could use as a horizontal center also, because there aren't many GOOD options.

Q. So if I have an AT screen, should I use 3 verticals versions, or 2 vertical and 1 horizontal.
A. Use 3 vertical. Although the difference is slight, might as well have them all the same.

Q. Do these require break in?
A. I'm often skeptical of claims that break in changes the sound dramatically. Especially with electronics. But in this case, the woofers are a stiff pro style driver that many people seem to find improves with break in. I too have experienced this. For fast break in, I suggest a sine wave at 35hz turned up until you see the woofer cone moving a couple mm each direction. Avoid ugly noises! Leave that going for half an hour. It should not be to loud as it's below tuning, and won't suck to much power as it's right on an impedance peak. Alternatively, play some heavy bass full range but be careful not to over excursion them.

Q. What is the power handling? Seems like it should be a billion zillion trillion watts but it's only 400 watts on the DIYsoundgroup website.
A. I rate my speakers conservatively based on where the subwoofer is crossed over and how much excursion could take place during high volumes. Many manufacturers state the peak power applied above excursion problems. If that doesn't make sense, just know that I'm conservative because I have no marketing agenda like other manufacturers do.

Q. Why use the DNA-205 and not the better DNA-360?
A. Better? Hmm. Well, the DNA-360 is really only better at crossing low. The design crosses at 1700hz so the 205 is actually better because it's cheaper.

Q. Is this speaker better than the Fusion XXX or JTR XXX or Seaton XXX or etc.?
A. If I haven't heard it, I don't know. All I can do is tell you the potential design merits of each according to published measurements.

Q. What surround speaker do you recommend to mate with these?
A. The Volt 10 uses a similar woofer, very small, affordable, has the benefits of coax, and seems quite popular. The Fusion 10 uses the same woofer, waveguide, and compression driver, and is designed by me so will have a similar timbre, but costs more and is bigger. Those are my two biggest recommendations.

Q. What about the 1096?
A. Good speaker, has a little less bottom end, doesn't have a kit available so you're totally on your own. It'll save you $80. Some days I think it's great, others I think why bother. It's there for you to decide.

Q. Where should I cross to my subs?
A. 80hz is my default answer. 70 is ok and 60 is barely doable. No less than 60hz is recommended.

Q. Can I run these full range?
A. What did I just say? Lol. You can run them full range, but power handling and SQ will go to crap. Not recommended.

Q. You suck at marketing.
A. Shut up Erich, that's not a question. It's only a fact.

Q. What is the best SEOS design, is this one it?
A. That depends. Wider will have better directivity. Some woofers will go deeper too. This speaker has a lot of great features, but some of the SEOS designs will offer better directivity and midbass. Pick the design that meets your needs.

Q. Soooo, these aren't good at midbass?
A. Yes and No. They don't have much natural extension below 80hz. But there are 2 10" woofers in this speaker, which is capable of lots of midbass. Midbass is a tricky subject that requires examination of the room behavior above all else.

Q. Where can I get the kit, I don't see it on the DIYsoundgroup website.
A. This kit is very hard to keep in stock because there are so many parts needed for it. As such, you won't find it on the site often. Check back often and it'll show up when the parts are available again. And sometimes Erich substitutes XO parts for available ones. So if you get a mills resistor or something a little different than what you see in someone else's thread, that's ok. It's only because the normal part wasn't available. We're trying to keep these in stock.

Q. How do I wire up the XO?
A. This might help: http://www.avsforum.com/forum/155-d...configurable-seos-design-46.html#post26315473
If not, you can hire mtg90 to build it for you. Or ask on the forum. What ever you do, please don't do it wrong to save a few bucks and live with a bad speaker. I've had some people ask what was wrong with their XO and it was completely shorted out and their amp was lucky to be alive. Doing this part wrong can damage stuff. Get the proper help and get it done right.

Q. What size amp should I use with these?
A. Something with at least 20 watts.

Q. Huh!?! But these can handle a bajillion watts, how can they possibly sound good with only 20 watts?
A. Well, they'll work with 1/4 watt or even an 1/8th watt. How loud do you want to play? 20 watts will give you about 105db sitting about 10 feet away (depending how you look at it). That's actually really loud. So for reference level, you'll want at least that. So yes, your little receiver will power these just fine. Wanna put a big pro amp on them, sure go right ahead.

Some of these answers are a little tongue-in-cheek ;)



List of some GTGs. There are more if you search around:

http://www.avsforum.com/forum/89-sp...jtr-psa-reaction-audio-1099-s-comparison.html

http://www.avsforum.com/forum/155-diy-speakers-subs/1980841-gtg-meet-plainfield-il-chicago-land-area-10.html#post35184898

http://www.avsforum.com/forum/89-speakers/1608938-vancouver-summertime-gtg-results.html

http://www.avsforum.com/forum/61-area-home-theater-meets/1964809-3rd-annual-upper-midwest-gtg-july-2015-discussion-6.html

http://www.avsforum.com/forum/155-diy-speakers-subs/1627817-going-away-party-popalock-diy-fest-gtg-speaker-listening.html
 
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#3 ·
Very nice! I see this getting alot of attention for use as a center channel for people without an AT screen. Can't wait to see the center channel config measurement. Tux, you make DIY great



Edit: Did you mean to type DNA-350 or DE-250?
 
#4 ·
Whoops. Thanks for noting that. It's the DNA-205. Fixed it now.


Ya, I think for non-AT, this is a very good option. Really quite affordable too. At least once Erich gets the SEOS10 made up in plastic it will be. Looks very nice to. Dimensionally very slender and appealing. My wife even liked it a lot, and believe me, she sees a lot of speakers go through our livingroom and HT. A lot of them.


13 part XO though, so not an easy one to assemble.
 
#5 ·
Two 10's, Two 5's and SEOS 10's. Is my eyeball math correct?


I'd drop by for a listen to this if you weren't on an island some 300 miles away. hehe


Looks very similar to what I am in the process of building:

Sealed boxes, SEOS 12's and some triple 15's; passive/active.
 
#9 ·

Quote:
Originally Posted by BassThatHz  /t/1479331/a-3-way-99db-multi-configurable-seos-design#post_23477216


Two 10's, Two 5's and SEOS 10's. Is my eyeball math correct?


I'd drop by for a listen to this if you weren't on an island some 300 miles away. hehe


Looks very similar to what I am in the process of building:

Sealed boxes, SEOS 12's and some triple 15's; passive/active.

Yup, quite a bit of firepower. You live in WA? I go down there once in a while.

Quote:
Originally Posted by coctostan  /t/1479331/a-3-way-99db-multi-configurable-seos-design#post_23477231


Congrats Tux. That looks quite nice and should work well for guys who don't have AT screens.
Quote:
Originally Posted by Scott Simonian  /t/1479331/a-3-way-99db-multi-configurable-seos-design#post_23477291


Cool project!

Thanks guys.

Quote:
Originally Posted by Sibuna  /t/1479331/a-3-way-99db-multi-configurable-seos-design#post_23477311


so its 40x12x????


curious how tall it is when laying down


looks interesting

It's 40x12x12. Final version might be more like 38" though. When laying horizontally for a center channel application, it's 12" tall. If it needs to sit on a stand though, that'll have to be a beefy stand. And if mounted into an entertainment center, the low end may sound over emphasized, but audessay should take care of that to an extent.
 
#13 ·

Quote:
Originally Posted by gpmbc  /t/1479331/a-3-way-99db-multi-configurable-seos-design#post_23477516


Nice to get the info on this guy! I'm obviously wrong, but I thought the speakers final sensitivity would be dictated by the last efficient segment. So for example the 5” drivers being much lower in sensitivity than either the tens or the CD.

The mids are around 98db/2.83V/m but then I knocked out a bit of sensitivity raising impedance and coil DCR. But then I gained back about 3db in bandpass gain from overlapping with the tweeter and woofers. XO points are about 750hz (with lots of shared stop band) and 1750hz. So that 1000hz in between gets some help. The mids are almost like a bridge between the woofers and tweet.
 
#14 ·
Tremendous! I am so glad such a Hi-Sensitivity option is available for folks with AT screens. All of my experimentation with line arrays sadly ended up with less than good results, you just cannot make up for that 3dB/octave rolloff and approach hi-90s sensitivity without a bad rolloff in freq response.....which starts even lower for a CBT design due to the curvature. Thanks so much for coming through with this design!!


Are you saying you are going to abandon the dual mid for a single mid version for both tower and center? Why? Bad polars?


Great work, Tux!!! Will there be a flat-pack in the works?



JSS
 
#16 ·

Quote:
Originally Posted by tuxedocivic  /t/1479331/a-3-way-99db-multi-configurable-seos-design#post_23477548


The mids are around 98db/2.83V/m but then I knocked out a bit of sensitivity raising impedance and coil DCR. But then I gained back about 3db in bandpass gain from overlapping with the tweeter and woofers. XO points are about 750hz (with lots of shared stop band) and 1750hz. So that 1000hz in between gets some help. The mids are almost like a bridge between the woofers and tweet.
Gotcha, I thought the celestion mids were lower in sensitivity 89 - 91 a piece depending on the magnet.
 
#18 ·

Quote:
Originally Posted by maxmercy  /t/1479331/a-3-way-99db-multi-configurable-seos-design#post_23477609



Are you saying you are going to abandon the dual mid for a single mid version for both tower and center? Why? Bad polars?


Great work, Tux!!! Will there be a flat-pack in the works?

Thanks!


No abondoning going on. The polars were very tricky to get right. A LOT of thought went into this design. But it paid off because the polars are very good for a 12" wide speaker. I am going to offer a single WOOFER design. So it'll be TMW. Saves $80 and 14" height.
Quote:
Originally Posted by bhazard  /t/1479331/a-3-way-99db-multi-configurable-seos-design#post_23477625


Very nice. I like it.


How low does it go? 65hz?

Thanks. That's a ground plane measurement, so you can see it hits an F3 of about 80 or 90hz. This surprised me when I measured because it sounds better than that in room. Then I listened in my shop and they were very bass shy. So I decided a shorter port will bring up the tuning and give about a 70hz F3. Right now the tuning is around 45hz. To low for this driver.

Quote:
Originally Posted by gpmbc  /t/1479331/a-3-way-99db-multi-configurable-seos-design#post_23477646


Gotcha, I thought the celestion mids were lower in sensitivity 89 - 91 a piece depending on the magnet.

Ya, the T/S parameter sensitivity is about 89db each. But the actual output is more like 91db in the pass band I'm using. So it is more like 97db/2.83V/m not the 98db I said. Still, where the 99db comes from is the bandpass gain. Inquisitive question
 
#20 ·
congratulations on another neat project tux.


the side-by-side mid is something that we discuss from time to time,

but i was wondering if you notice any weirdness off axis because

not only is the level down, as it is with the horn, which is fine,

but the drivers are also increasingly out of phase with each other,

which is what causes the reduction off axis in the first place.
 
#21 ·
Thanks LTD02.


There is some weirdness with side by side mids, and its not something I would do again unless I knew I could cross low. I was somewhat forced into crossing below 2khz. My first XO was at 2khz but the polars were very bad right at 1900hz. Had the MTM center look. I have them saved and could pull them up sometime for separate discussion.


Basically with the horizontal mids, I got a smooth gradual off axis 90d beam width from 800 to 1750hz. Below that it went omni, whereas the 10" woofer actually has a little bit of directivity still left in it. Above that it became extremely directional and problematic.


Before I selected the driver arrangement I modeled the driver interaction behavior using PCD, just to see. I could see the sudden directivity narrowing in the model, but it didnt seen as dramatic as measured, and it was above 2khz. I was a little surprised when I took my initial measurements, because the SEOS 10 is a little wider beam width than the SEOS 12, and the mids narrowed up so tightly. I thought a XO at 2khz would blend, but it didnt so the final result landed around 1750hz. The nice thing about the low XO is the vertical lobe is nice and tall. And the power handling is nearly as good as it would be at 2khz. I'd give these 300 watts without much concern.
 
#22 ·
Finally a thread started for this beast!
This project has been in the works for a while, and it's nice to see that's it's completed. Tux had a lot of experience with that woofer and compression driver, so it's great that he was willing to help with this speaker.


I've decided to try and get the SEOS-10 done in plastic as well. It's not going to be easy, but I'm going to do my best. There will be a pre-order for them going up shortly and I'm hoping to have samples in a week or two.


This weekend I'm going to go through all the audio gear left from group buys and get some photos for a DIY "yard sale". I know I still have some JBL woofers and mid sized horns/compression drivers and a good number of fiberglass waveguides and horns. Hopefully that will help out with this SEOS project.
 
#23 ·
Tux, Erich,


I hope everyone understands the effort you guys (and many others) have gone through to bring really terrific speakers to HTs and Stereos all over the world, for a fraction of the price of a Big Box store's inferior offerings. I wish I could have contributed with CBT/Arrays, but sensitivity problems hindered that project, and it never got out of the modeling stage. Power requirements were too high (most line array/CBT enthusiasts will not necessarily tell you this). I am so glad Tux went through with this, and offered a true high sensitivity option for Non-AT screen HTs.


Thank you.



JSS
 
#24 ·
Here's a minor challenge for the for someone with AutoCAD or similar skills...


Draw up a single flat pack box that can be used in the vertical or horizontal configuration. In simple terms, make 3 square baffles that can be arranged as TMWW or WTMW. Square so the TM module can be rotated 90 degrees. Let's assume we can deviate an inch or so from the original dimensions if needed. 3 - 12x12 baffles + 3/4" braces between them gets us to 37.5" x 12 overall. 39 x 12 if the top and bottom "overhang" the baffles.


Or am I the only that thinks a convertible baffle is a good idea?
 
#26 ·

Quote:
Originally Posted by mobeer4don  /t/1479331/a-3-way-99db-multi-configurable-seos-design#post_23480333


Here's a minor challenge for the for someone with AutoCAD or similar skills...


Draw up a single flat pack box that can be used in the vertical or horizontal configuration. In simple terms, make 3 square baffles that can be arranged as TMWW or WTMW. Square so the TM module can be rotated 90 degrees. Let's assume we can deviate an inch or so from the original dimensions if needed. 3 - 12x12 baffles + 3/4" braces between them gets us to 37.5" x 12 overall. 39 x 12 if the top and bottom "overhang" the baffles.


Or am I the only that thinks a convertible baffle is a good idea?

I already have that drawn up.


But the problem is that 3 small boxes will use more wood than 1 larger box broken into different compartments. Plus shipping would be heavier.


In the end, I think it might be cheaper to just make up a couple different layouts and get flat packs cut.
 
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