Hi all, new here and hope someone can help advise, i could tell a long story of why this question interests me, and i will if need be, but to get to the point the question is what size and position should i aim for , opting to enrich/enhance a currently empty semi acoustic guitar? It's for an all maple Ibanez hollowbody, (Af75), which is very plain sounding, and even on changing for quality pickups as i did with my also Empty ( but not quality wood) Antoria Jazzstar, i'm not confident it will have the desired effect as no pickups have made my Antoria sound quality, it's just decent, and i feel this maybe due to it being totally empty inside also. I'm leaning toward this idea as the best sounding guitar i had was another ibanez slim body semi, a chuck berry gibson style copy, which i was told by a guitar builder was better than the real thing, he also stated it had a solid block of mahogany within, hence why i,m thinking of this. My antoria is far too heavy a guitar to even think of this option, but my new Ibanez has thee most perfect action/neck/playability, that i'd really not like it to just sound ok, like my antoria. I'm thinking as the pickups are getting changed and will make an improvement, i should attempt to glue some Mahogany pieces inside to enrich the rather plain sound, Going through the pickup cavities, im only going to get a smallish piece at a time, so im thinking maybe have a few pieces cut to align within as a block? i currently have an Epiphone ES-175 which has been sold as i did not like the neck/playability on/of it, but it to had a rich sound which would easily give smooth overdrive, which has been so difficult to get with my Antoria, which tended to sound harsh regardless of effect or amp, it's loud, bright, but not rich. I'm worried the pickup change is just going to give me a "decent" sound like my Antoria, and i'm thinking the common thread here is the lack of soundblock, which obviously was a factor in the quality sound of my prevous Ibanez which i had many years back, and sold as it was a slim body and became ornamental as i favour wide body semi's only. I don't know what is within the Epiphone ES-175 Premium, but it has that quality "Easy to smooth overdrive" sound i aim for. Although my Antoria has a decent sound with good pickups, it's still very plain in relation to a quality guitar, which i thought may be down to the wood, as the Antoria is unknown wood, but most likely far from decent and very heavy, as it's a true Full body wide and full sized, but this new Ibanez is made of all Maple, but that alone is not generating a quality sound. really just need to know what depth/thickness and overall size should i be aiming for, and where exactly should i position it within? It's not going to add much weight to the guitar and may well enhance the sound some degree, moving it towards these other two i have mentioned. Well, that is the whole story, mainly, but the important question is at the top, thanks to anyone who can advise.