Hey guys...we need a little rallying here... - Page 116

Well, hey then. I've designed a special crossover just for you! (Please close the door before you crank up the volume).

I actually figured the more complex crossovers were better. Harder to build, but better in the end.

I just didn't know how noticeable the "finicky" part was. Your wording threw me off a little because it sounded as if it could be used or skipped. Now I see that it's not *really* finicky at all and should be there.

Bwaslo, nice designs. I'm wondering though, isn't the whole point of such a large design directivity and efficiency? Seems you have directivity, but the efficiency is obtainable from much smaller. And couldn't we get directivity from a SEOS 8, just higher in frequency? How much would that matter?

Not criticizing just trying to learn about directivity. I'm also a small speaker kind of guy

How frustrating! It's pitiful that I'm so crossover illiterate I don't get the joke(although I think it is that the CD is not padded so would be so friggin' loud it would blow you out of the room?)

Sorry to put a damper on your joke. It's never as funny when you have to explain it to someone . And by the way, you don't need to bother explaining it to my ignorant *ss.

Main point (for me) is directivity. Efficiency is nice, but not really a big deal, really good amplifier power is CHEAP nowadays (lots of good class D amps around). But if you happen to be a SET afficiando, then efficiency is more of a requirement. Ideally you'd like directivity down to where the room modal pattern starts to dominate things (around 300Hz).

The crossover gag is just that it's just a single capacitor, won't do anything much more than keep DC out of the horn driver. Would sound horrible, in this case. Though a lot of cheap cone tweeter 2-ways in the 70s used a single cap for the crossover, and weren't horrible in response (though "flat" wouldn't exactly describe them).

Ok, so even smooth transition directivity up around a 1.5khz cross over isn't as desirable as going big and getting pattern down below 1khz. My smaller designs seem to have a smooth transition, yet much higher directivity point. The price I pay for small 8" drivers I suppose.

Well, "ideal" and practical are two different things, there are always tradeoffs. Ideally, we'd have a time machine and go back and hear the Beatles playing in the Cavern, 1963.

LOL!

Thanks for all of your hard work! What you & Eric are doing is an amazing gift to the DIY community. I really appreciate it!

I have 200 watts into 8 ohms, so I have plenty of amp. I can't wait to try one of these CD designs. How would you compare the SEOS 12 with the Dayton DS 12 with one of the designs with a really high end woofer like the AE TD12s or JBL 2226h? Pretty close sound quality wise? I know those other woofers are a lot more efficient. Just curious from a nubee point of view.?

The DS12 / SEOS12 is probably one of the best value designs around for what you get. I know a price hasn't been posted but you can imagine based off the cost of parts that it's a great bang for your buck.

But with the DE250 having 108db/1w efficiency (AFAIK), it screams to be mated to a high efficiency 12/15.

Personally, I think that's what everyone is going to hold out for. I've never had mains capable of playing 115db+ so I'm really interested to see what comes next.

That is what is so exciting is that the designs so far are not the "High end" woofers yet and the measurements look really smooth. Looks like it will only continue to get better!

+1. I'm just trying to figure out the % of performance the DS12 is to one of the high end woofers. It's so darned reasonable!

Except for maybe the risk of voice coil heating (not likely an issue for home uses), the max output you can get is just based on cone area*xmax, efficiency doesn't really come into it.

I haven't heard a TD12, just a TD15M. Probably if I were building from scratch (and keep in mind I'm cheap and not impressed with "high end" things usually) I'd go with a DS12 design... and of course some subwoofers, still. Overall size is a consideration and these TD15M boxes are stupid big for my living room! Or maybe some ceiling-mount SEOS/ShadedHLA things (though no one has built or heard that yet, just expecting/hoping that to be good).

But no one has ever accused me of having golden ears. I can't even hear the effect of brilliant rocks!

Too bad there isn't a 15" version of the Designer Series woofers.

I am running my speakers off AVR, no separate amp, so efficiency is important to me - and my LCRs are fairly high efficiency already - so I'll be scouring for high efficiency designs.

Chase Home Theater - SHO-10 center, PRO-10 L/R, and 4x PRO-10 for surrounds.

It's because I use special quantum-based supersymmetric nuetrino tachyon techonology in my crossovers. The govt won't let me say more about it.

Part of it's the smoothing, but look at the scales on the datasheet graph. That 'mess' at 400 to 600 is only about 3dB deep.

Also, I'm not sure those response measurements are quite right -- they weren't measured by Dayton, but by the manufacturer (NOT using OmniMic!) overseas. I've talked to the people at Dayton about redoing the plots themselves. That peak the plot shows at 150Hz makes no sense at all, I don't know how a low fs woofer could do that. Here's what I measured on that DS12 woofer (1/48th octave res, about 20" away):


For comparison, here's what I measured on a TD15M under similar conditions:


I do tend to focus on the 6th octave type stuff, particularly for dips.

Either of the Eminence 12 designs are high efficiency, 98dBish.

Edit: make that 96-ish. Eminence reads their sensitivity up where you'd have to bring the curve down from to get it flat.

Well this one only goes to 150 and gets a little wonky before that, prob b/c of the box size........

Really though I dont understand why we're not looking all the way down to a reasonable crossover point.....??

This is true. How is the low end for the eminence drivers?

I'd imagine they need to be crosser higher and have less bass then the designer woofers.

I'm curious how the designs using 15" drivers will do. Lower response and high efficiency. I guess it's possible with something like the 2226h? but that's really pricey.


You read my mind.

Because:
(1) I'd have to go outside to measure it all in one curve. My indoor anechoic chamber is closed for remodelling. And these things are heavy and my heavy lifting personnel is managing his lawn business.
and
(2) The low end below about 200Hz is all Thiele and Small and room/box. You can get the driver response there from the T&S parameters. The box I measure in isn't the box design you're likely to use (at least not without some porting; though the Designer12 was pretty well matched to the sealed box, might be why it sounded so good).

Edit: well, maybe the box was ok for the Eminence drivers, I just ran them on WinISD (as did someone else previously here). But the bass sure sounded light compared to the DS12. I remain ignorant of why.

Is that the Delta and Deltalite series?

I was thinking of trying to get as efficient as possible by using one of the Delta series. Not saying my idea will work but I am hoping to use a small amount of power, say 50-100 watts, for indoor and outdoor situations.

I've been playing all of them with a 50W amp, even the Designer12 version. Just one listener, not playing disco levels or anything. If you're splitting at 85Hz or so to a sub, 50W should be plenty for non-earbleeding home use.


The various new SEOS designs are being collected in separate threads here:
http://diysoundgroup.com/forum/index.php?board=2.0
PLEASEdon't post there, yet, though. Erich hasn't officially opened the forum, things might change, anything posted may get wiped out while the forum software gets messed with.

Gotcha, thanks for your work and your light years ahead of me on design comprehension, I ask questions so I can learn and understand better. I wasnt aware the box sizes were still not determined.

I see how the low end would be controlled by the factors you mentioned, I'll sit back and be patient.... I'm just impatient and cant wait to see a response with box dimensions and alignment determined, flat to like 80...... Am I not paying you enough?

Cheers,
Nicholas

Once I make some ported boxes that are the correct size for each woofer, things should look even better. A sealed Deltalite in a 2.25 cu ft box is simply holding it back from what it does best. Because the pro woofer boxes will be used with subs, I'm hoping to go around 2 cu ft tuned to 60hz or so for the Deltalite. That should get them pounding pretty good. They can handle dance club midbass, so I think they should do pretty good in a home theater.

BWaslo said he goes to dance clubs every other weekend just to check out the woofers......and "Keep my old school moves fresh for the newbs." Not sure what that means, but maybe he was a break dancer back in the day after the disco craze.

The DS series might have another box option allowing for full range if I build the right enclosure and tune it low enough.

As mentioned, things should be shipping in about 2 weeks. Not sure how long it will take to get here though.

Which woofer option(s) are slated for a sealed alignment? Any?

No reason you guys should have all the fun. I did some simulations last night and yes the delta lite wants a big box but its hampered by its 4.9 mm xmax. I had to high pass at 50 hz and limit power to 100W to keep it below xmax but it still beat the Dayton on SPL. The Dayton with 5.5 mm xmax goes lower but not so low you don't need subs. In 22L sealed with 60 hz HP, it could take almost 2x its RMS power w/o overexcursion. It seems to me that the smaller sealed alignments will integrate well with subs and so no need for the larger ported boxes. Am I right and if not, what am I missing?