Quote Originally Posted by GM View Post
Basically. A bigger horn 'throws' the sound further and controls directivity to a lower F6 and why I prefer the 511 to the 811 and the 311 to the 511, etc.. The trade-off other than size is that when used with a point source driver (woofer, etc.) is that the XO point must decrease with increasing horn size for a given polar response which in turn increases its required delay. Fortunately, these are no longer the major issues they once were now that adjustable digital XO, delay systems are available.

Basic cab tuning is strictly a function net Vb, so all you need to do is increase its dims enough to account for the additional volume taken up by the larger horn/whatever.

Not having ever experimented with using a 511 with a ~1200 Hz XO, not sure how well the M19's XO will line up electrically with the horn's gain BW or if there's enough mids, HF tuning adjustment, but for sure the 511 will ideally need the same driver offset to line up acoustically for the XO's point(s) to work, making it extend in front of the woofer/cab by however much longer it is. IOW, mount it same as an 811 and you'll need a much lower XO point for best performance.

GM
Sometimes this is hard for me to get my head around...so here goes.
I should have the 902 driver in the same position as it was with the 811 & therefore the set back from the front baffle will vary accordingly?
I may not have enough adjustment in the MF & HF L pads? So I'm assuming that the 511 will change the sound balance & I may need to adjust the L Pads?

Cabinet tuning seems fairly straightforward....just alter the volume to allow for any increases/decreases with the new horn or cabinet design...and keep the port the same.

Quote: Rontec - "I noticed my 511b / 808 8b's seem to have a more opened sound than my 811s. (Valencias and 19's) But it was a larger room as well. Have you tried just setting the 511's on top of the 19 cabs and running them from there for a while? Before you do any major mods!"

I noticed the same openness of sound when I changed from 811 to 511 on my A7's...and it wasn't just a subtle difference. I won't be modding the original cabs, I'm going to keep them in storage, as they are original. I'll build new cabs & use 1 inch ply with additional bracing. I'm keen to see if this improves the sound, so I might as well build them to suit 511's.

Quote: Panomaniac - "A matter of taste, I suppose. For domestic listening I much prefer the 811. It seems lighter, cleaner, clearer to me.

But I seem to be alone in this opinion."

Nothing wrong with that, everyone listens differently & I have to say that I love the sound of my 19's just as they are. Just can't help myself to try & see if they get any better.

Thanks for the input everyone,
John