Plywood

I'm currently cutting the panels for the 4 HD15s I'm building and am kinda worried about the quality of the wood. It was bought for £15 per 8x4 sheet from a builders merchant and when it was delivered I was aware that it wasn't void-free, but it has only become fully evident just how rough the wood is now that I've begun cutting up the sheets. Full of gaps, basically. I'm not one to compromise on quality when making stuff, but it's too late to send the wood back now, and it will have only cost me £60 in wood for 4 HD15s. If worst comes to worst, once these are made I'll sell the empty cabs dead cheap and build another 4 with some quality wood. This is my first speaker build so I guess it's wise to get some practice in first anyway. Thing is, I just want to know what I'm in for! The other day RUS was asking about ply and received mixed responses. I remember deadbeat stating that poor quality ply makes cabinets 'sound horrible' but others weren't quite so fussed. I know it's gonna be subjective to a large degree, but the wood I have really is quite crappy, on the whole. I will, however, be filling every hole I find with gripfill before constructing the cabinet, but obviously this can only be injected a certain distance into the panels and there will inevitably be holes which I can't get to and therefore can't fill. I guess what I want to know is, how obvious is the difference to the sound quality when using crap/quality plywood? Thanks ppl

If these are your first build, then cheap ply will be ok. Any mistakes you make will only be cheap ones. Then you can always sell them on ebay, and remake them with void free ply.