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:
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.
After more feedback on this design, I've provided some tweeter level and tuning options that can be found here: https://www.avsforum.com/forum/155-di...l#post25958610
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: https://www.avsforum.com/forum/155-di...l#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: