[quote name='stevie' post='1320974' date='Jul 29 2011, 11:57 PM']I think you always have to try to compare like with like. Yes, you can get hi-tech 10s that will do wonders, and 12s that will outperform many 15s.
Interesting that you bring up the question of driver quality though, because the total cost of the drivers in a 4x10 is about three times that of the equivalent 1x15. Anyone trying to buy a half decent set of 10s is going to be spending over £200. Spend £200, or even £300, on a 15" driver, and your 15" cab becomes a completely different animal.[/quote]
I was comparing just single drivers & not 4 10"s to a 15".
In the OPs case, if he likes the sound of his 4x10 & wants more of the same, then an Ashdown 4x10 would be as close to getting that. Adding a 15" to it alters the sound (as you know, with varying results).
The debate of will a 15 go lower than a 10, it depends on how the cab is tuned. Taking out the equation of how loud you're wanting it to go for a mo, if you managed to perfectly tune a cab for the 10 & a cab for the 15 & both drivers was of a high spec, then both should be able to produce the same frequencies.
Adding in how loud you want it is how much air you can move. So a 15 can move more air, therefore in theory, be louder. You add more than one 10 & you're moving more air, hence more capable of moving more of those lower frequencies. 4 10" drivers covers more area than a single 15, so should move more air & if the cab is tuned appropriately, should move more lower frequencies also.