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A 3 way 99db multi configurable SEOS design

post #1 of 699
Thread Starter 
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



Yes, it does slope down like that. I have an optional resistor change to raise the top end a bit more. It sounds very good like this. Not bloated. Very dynamic and powerful sounding.

Here's the final impedance (optional resistor drops the very top end down to 3ohms.)



I measured it, but forgot to save it so all you get is the simulated impedance, which measured bang on. 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. I definitely need to explain this a bit. Here's the side by side woofer portion for the center style.



This chart shows the general woofer to mid XO region.

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, and then hopefully I can remeasure and see the improvement.

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


There's also the tux10-96 which uses one woofer instead of two and is the 8ohm version.


Edited by tuxedocivic - 9/13/13 at 4:02pm
post #2 of 699
Awesome tux!
post #3 of 699
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 smile.gif

Edit: Did you mean to type DNA-350 or DE-250?
Edited by cogeng182 - 6/28/13 at 1:27pm
post #4 of 699
Thread Starter 
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.
post #5 of 699
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.
Edited by BassThatHz - 6/28/13 at 2:00pm
post #6 of 699
Congrats Tux. That looks quite nice and should work well for guys who don't have AT screens.
post #7 of 699
Cool project!
post #8 of 699
so its 40x12x????

curious how tall it is when laying down

looks interesting
post #9 of 699
Thread Starter 
Quote:
Originally Posted by BassThatHz View Post

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 View Post

Congrats Tux. That looks quite nice and should work well for guys who don't have AT screens.

Quote:
Originally Posted by Scott Simonian View Post

Cool project!

Thanks guys.

Quote:
Originally Posted by Sibuna View Post

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.
post #10 of 699
Cool thats prob too large for me, still cool however. Ill need a center at some point might go with the alchemy mtm or just keep waiting
post #11 of 699
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.
post #12 of 699
Very cool and unique design!
post #13 of 699
Thread Starter 
Quote:
Originally Posted by gpmbc View Post

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.
post #14 of 699
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
post #15 of 699
Very nice. I like it.

How low does it go? 65hz?
post #16 of 699
Quote:
Originally Posted by tuxedocivic View Post

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.
post #17 of 699
Woot!

As for midrange sensitivity I do think they are around 91-92dB each, put two in parallel and you get +6dB @ 2.83v or 98dB.
post #18 of 699
Thread Starter 
Quote:
Originally Posted by maxmercy View Post


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 View Post

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 View Post

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 biggrin.gif
post #19 of 699
Trying to learn, thx for the info Tux smile.gif
post #20 of 699
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.
post #21 of 699
Thread Starter 
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.
post #22 of 699
Finally a thread started for this beast! biggrin.gif 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.
post #23 of 699
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
post #24 of 699
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?
post #25 of 699
Thread Starter 
That would be excellent if someone could figure out that kind of puzzle. I've been wondering how to do it. Most people who want this speaker will want 3. Two of them vertical and one of them horizontal.
post #26 of 699
Quote:
Originally Posted by mobeer4don View Post

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.
post #27 of 699
What about making the front baffle 3 parts so you can stack them as you need? Same large box for all configurations, and no added weight, the baffles would just glue on to one box
post #28 of 699
This is the center I've been waiting for. I'd wager a good bit of us don't have AT screens or even screens for that matter. Very excited about this. Thanks for all the effort by everyone involved.
post #29 of 699
Quote:
Originally Posted by nater1 View Post

What about making the front baffle 3 parts so you can stack them as you need? Same large box for all configurations, and no added weight, the baffles would just glue on to one box

The inner bracing needs to be in different places for different layouts.
post #30 of 699
I see what you are saying, and while I am sure there is a way around it, it may be more complicated than its worth, lol
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