I'm deficient in tonewood knowledge. Hence, I need someone to tell me the differences between 2 guitar's body specifications. Which one is better? And why?
Agathis top.
Sapele back and sides.
Spruce top.
Mahogany back and sides.

Thanks in advance
Last edited by buvi.airen at May 12, 2017,
I don't believe I've ever seen an acoustic with an agathis soundboard. What model are you looking at there?
Sapele is generally considered pretty similar to mahogany as far as tonewood goes.
buvi.airen  Well, some of the depends on the price range we're discussing. "Agathis", AFAIK, is a budget. lumber shortage sort of an excuse for a guitar top. I've never heard it mentioned as a top for any mid or high price guitar.

"Spruce", includes several species, Sitka, Engleman, and red, which includes the legendary "Adirondack"variety. Sitka is likely the most commonly available,primarily due to the fact it is the largest of the genus, (Picea sitchensis). It sounds good, and is suitable for finger picking and plectrum styles. Sitka doesn't "load up", or "compress" under heavy pick playing, so you can pretty much bang on it to your hearts content. The most common other top wood is cedar, but it is better utilized for finger style guitar, including classical.

"Sapele" sounds fairly similar to  "mahogany", save for the fact it, (IMHO), is a bit brighter and tighter.

True, or, "tropical mahogany", is largely unavailable due to CITES limitations on the cutting and exporting of these endangered species. The same is true of Brazilian rosewood.

Accordingly, the guitar makers have taken to calling the more available, "khaya" species simply "mahogany" or "African mahogany". http://www.wood-database.com/african-mahogany/

Since "perspiring minds want to know" (*), here's a more lengthy blurb on the topic:  http://sixstringacoustic.com/sapele-vs-mahogany-whats-the-difference-and-which-is-better
(*) Oops, I meant "inquiring"...
Last edited by Captaincranky at May 12, 2017,
Those two choices are reasonably close in physical properties, so I would say that any differences would be overwhelmed by other variables, like size, top thickness and bracing pattern. I might rank them 1 and 2 in one make and/or model, and 2 and 1 in another, because I keep a very open mind about what I like in relation to tone woods, and it often comes down to individual guitars rather than models. Any differences become even smaller if the back and sides are laminated, and even less it the top is also laminated.

Did you have specific guitars in mind?

EDIT. Agathis is in the Araucariaceae family, the same as bunya. I think that bunya is a terrific top wood if you don't mind the look, and Agathis timber also has a good stiffness-to-weight ratio that potentially makes it a good top wood candidate. - So wouldn't be prejudiced against it just because it isn't well-known.
Last edited by Tony Done at May 12, 2017,
Quote by FrogstarWorldA
I don't believe I've ever seen an acoustic with an agathis soundboard. What model are you looking at there?
Sapele is generally considered pretty similar to mahogany as far as tonewood goes.

Both of them come from a local brand in my country. Not a well-known brand in the world. I went there looking for a beginner guitar. Maybe I should buy from some of the world's most valuable brands. However, I just want to know more about tonewood first. Thanks for your answer.
Agathis and sapele are thought of as budget woods while spruce and mahogany are a gold standard  so spruce and mahogany is probably going to have better resale value.  Just something to consider.  Both wood combinations can produce good guitars.
Not taking any online orders.
First I ever heard of agathis used in an acoustic. Learn something new everyday. Another important factor is whether the wood is solid or laminated. IMO that's a bigger factor than the species of wood. A solid top resonates better but that's not to say laminates are bad. Some are decent. My favorite combination so far is solid sitka top and laminate rosewood back and sides. 

Don't worry too much about so-called "tonewood". I have never ever met anyone who could tell what woods a guitar are made just by listening to it. Then when they see the guitar they say stuff like "oh yes, you can definitely hear that lovely mellow rosewood, duh, duh duh  . . . . . hype.

Go to a guitar store, play as many different guitars as you can, then pick the one you like best.