Pretty hard to tell, even though I've tried plenty, since most of them have those horrible bronze-wound strings. The new Epiphone Masterbilt Deluxe would be nicer if it had good strings, for instance. It's relatively loud. The funny thing is, I played one just last week and I thought it had flatwounds on it but the Epiphone site says Phosphor Bronze and I can't imagine the one I played was used.
The Martin acoustic bass I played at a Guitar Center when I was in the States this past spring. There was definitely a rich acoustic quality to it that far surpassed the various low-to-middling end Asian acoustic basses I’ve played/own. Nevertheless, I’m happy enough with what I’ve got. But if money were no object, sure I’d get that Martin. I mean, I could buy it if it were a priority, but it’s just not a high enough priority. The thing is, I really enjoy my "O Bong" acoustic bass that I keep out in my apartment so I have a bass to play at home during the week. I sort of couldn’t enjoy it more, actually; and if it were more expensive, I’d just worry about damaging it or it getting stolen or whatever. But that Martin sure did sound nice — surprisingly so (to me).
Ernie Ball Earthwood. Guild B50. Emerald Balor. Martin B1. Taylor-Klein AB1. Tacoma Thunderchief. Roughly in that order... Mostly out of production, all expensive and large. Balor NBD posts including pics and clips starting here: New Emerald carbon fiber ABG - impressive! For strings (yes, they make a huge difference), my favorites for ABGs: New from GHS: Pressurewound Bronze
I also have a fretlesss MIK Epiphone El Capitan that I like. It’s body is bigger than the other acoustic basses I’ve played and it accordingly puts out more low end. I wish I had gotten one of the fretted version back when they were still made in Korea (quality was good towards the end of the Korean run. Might be fine now too, I haven’t kept up with it).
Wow, you got to try all the legends (if the much maligned acoustic bass category is even allowed to have legends, lol). Pretty dang cool. Man, I’d like to try some of those. The Earthwood would seemingly just be too big for me though (still would like to at least bang on one for a few minutes), and the Baylor wouldn’t personally be my cup of tea (though I appreciate that you really dig them). That Taylor-Klein AB1 sure is a looker... I shoulda gotten me a Tacoma Thunderchief back in the day. There were rumblings (so to speak) even back then about how good they were (also rumblings about fragility and provenance, as I recall), but who knew it would go out of production so soon and become the stuff of legend
It will likely be moving up in the list once I get the GHS Pressurewound Bronze on it. Hard to do a really fair direct comparisons, but one of these days I will do a long-threatened "Big and Loud" rundown thread.
I have a Martin B1e, which offers excellent tone and better volume than most abgs... as loud as any Tacoma I've met. Very clean and thumpy. If I was looking to buy an abg strictly for unplugged tone and didn't need max projection, I'd go for one of the Martin mahogany models. My Mota custom is, in dimensions, much like an Earthwood...it has much more volume, and a bit more air in the sound, especially played near the neck. If I need more whomp and less whoom, I move my plucking hand toward the bridge. Both of these run tapewounds for a more urb sound. That may be taking a little volume off, but it gives a tone I prefer, including less finger noise.
Guild B-30. With bronze roundwounds. If you want it to sound _really_ good, throw a set of tape wounds into the back of a moving garbage truck and _then_ play your ABG. Tone for days...
Don't laugh. I got one "by accident" off ebay one evening after a few beers. The big body projects better than any other ABG I've tried. No it's not easy to play. No I'm never going to gig with it. (I'm embarrassed to even talk about it here)
All the big names have been listed, if i were going to buy an acoustic BG, though. I would get either then Ibanez or Deans that are everywhere. Probably the Dean as i actually really like their acoustic instruments. Especially for the buck.
One current model hasn't been mentioned yet - Lamont touts their flatback model as a worthy successor to the Earthwood, and the boatback as a step further. Very droolworthy, would love to check one out some day. Lamont Flatback Ephraim Utah | Acoustic Bass Guitar and Earthwood Bass Successor Utah - Lamont Guitar Company
Believe it or not, the best one I heard was an Applause (Ovation value line) AE140. I miss my old one dearly. It was super loud in the mids with balanced lows and highs. The best way I can describe its tone is that of a loud, acoustic Jazz Bass that responded well to finger dynamics. That thing easily kept up with two acoustic guitars and hand drums in terms of volume and usable tone. Also, it's unique "bowl" shape made it much easier for me to play than the standard shapes out there.
Eoiohone has its act together when it comes to ABGs IMO. I’ve got a fairly old set of phosphor-bronze strings on my Epi El Capitan. It has none of that godawful bronze sound I think you’re referring to. It’s got a solid fundamental with just a little singing quality on top. It sounds more like it’s strung with some sort of bright flat or LaBella copper white nylons. But I also think that preamp has more to do with it than anything else. Epiphone contracted with Shadow of Germany to do the eSonic preamp (and I’m guessing the pickup) on the model I have. Looks like this: That EQ “shape” control sounds absolutely marvelous to my ears. It’s the only piezo preamp I ever heard I liked to sound of. Very organic with some really complex and musical mids - minus any of the usual piezo harshness.
I really like my Washburn AB-45. Came with rounds which sounded terrible, put flats on it (chromes i think) and sounds great unplugged! When using a pick it’s loud enough for small acoustic practices (without drums).