New speaker design?

[Whitneyville1]

The ES180Ti-8's are on clearance for $80 a pair less than the new version. This will very nearly pay for a pair of RS-28A's to make a 15-18 liter TM. The cross-overs won't be dirt-cheap with the notch filter needed to tame the break-up on the ES, but it shouldn't be that complex either. Is there a proven design yet with this pair? I'd like to make a build with "premium" drivers and this looks like a good chance to do things at a super value price.

Off the top of my head, it looks like about a 2 mH iron core inductor on the woofer and a 4th order electrical XO @ about 1500Hz could work tuned to the mid 30's in a ported enclosure. They should work as pretty much a high-end "reference" speaker and my "ultimate" builds as my ears aren't equal to the drivers.

What does everyone think about this?

[ani_101]

It's 40$ less, not yet, but that is also an almost RS28. One of the designs with the original ES180Ti used the esoteric tweeter by Bill. Dan's design uses the newer ES180Ti but uses the TL tweeter IIRC. Not aware of any design with the RS28, though it would be do pretty well..., you need to cross low with the ES180

[rpb]

Edit... (Better sim a few posts below.) Here's a couple sims for you to ponder. The dip is an estimate of the baffle compensation needed.

[Wolf]

No Dan's Premios were the older model ES180 esoteric. N26CF-R, iirc.
Wolf

[Whitneyville1]

PCD gurus, the 3 mH 16 ga. ERSE "Super Q" iron core looks like it slams the door on the ES-140's break-up, but will the RS-28A "come on" soon enough? Will a 2nd order LP filter do the job?
Frankly, I have a mental block when it comes to Excel, so I need lots of help and advice on XO design.

[rpb]

I made this sim to prove that a simple filter wouldn't work. I was totally surprised to come up with this in about 10 minutes.

[Whitneyville1]

Thanks a lot rpb (is it Robert?). To you speaker design guys (like Wolf, et al), is 30db down on the "trash" at 3500Hz considered "enough"? Would a third or fourth order hand-off to the RS28A be a good choice? These are music speakers and I have a sub, so raising the F3 into the 40's would be fine. They'll have to sit about a foot or so from the back wall and maybe a foot+ from the side walls in my tiny living room. I didn't realize the ES-180Ti took a whip, chair and gun to tame.

[rpb]

I think 4th order at 1.6k should be good with a capable tweeter like an RS28a. The 2.1k sim might work well with a wider variety of tweeters, but the xo I posted would be very expensive compared to the 1.6k sim.

That bump at 1k would bug me. Extra parts take care of it though. The response above 6k might be better if suppressed, but at what cost?

[Whitneyville1]

Ok, reality check. The ES-180TiA is probably worth the price in XO complexity and SQ in the mids. So if I go that way, is there a "better" tweeter for under $150 each I can hear the difference in than the RS-28A/F? My aim is to build an "Esoterix II" (with compliments to Paul Carmody) as very good SQ, very good value near "reference quality" TM's. Is this build a worthwhile project?

[rpb]

I think it comes down to what you really want from the speaker. I've built a lot of combinations using various drivers that were under $50 each. Peerless HDS and such for woofers, and some Morel tweeters mostly. The Morels were purchased a long time ago, and are roughly $80 now. I've also played with some cheaper drivers. I have pretty much hit a wall of how good, or maybe I should say, how much I like my speakers. Some are better on some music, and others excel in different ways on other music. I currently have a 3-way cobbled together that uses an inexpensive tweeter, and HDS drivers for mid and woofer. It really shines on some of my music concerts like the "Cream Reunion Concert". I don't think any of my 2-ways are better on that concert, even though they use the same, or similar woofers, and a better tweeter. I push the SPL a lot on that concert, and usually without the sub. (Just because I can. It's cool to have a pair of speakers that handle things effectively without EQ, or subs.) I should try the Morels in the 3-way again, and I will eventually. I've experimented with unusually high 2-way x-over points. In theory, they shouldn't sound too good, but one really was interesting. I may try the cheap tweeter on that one.

[ani_101]

Try a TL labs tweeter or the Arum Cantus AMT. Both can cross low, but again depends on how exotic you want to go, though the realistic gains will be minimal over the RS28A on paper.