Crunched some #'s and finalized the approx volume/tune...
Update... Officially I'm impressed... no small feat.... 145db or more was a good guess for sure, and now since I've had some time to set everything (str8clippin') Lp, Hp and gains...I honestly believe that the install (port location) is really close to optimum for what I'm trying to achieve (Sq/SPL)... it sounds phenomenal on music IMO, (I just play with the sub gain a bit ill the the fronts image well and you got staging or drop the knob to SPL). It's accurate and punchy without being obnoxious till I gain it up a bit, (and it still digs fine on music... Bless cabin-gain) then it'll Bang hard (SPL)...i'm guessing 147db+ or so?... lol... who knows?.. the ol' ear-o- meter has been broken for years... bottom-line is that I'm extremely pleased with the result... and that's what matters.
Shout-out to those OG's out there on the forum (too many to list) who've pushed, cajoled and flat-out told me the deal from time to time (medicine is never tasty) but goin' from the 90's with HC systems into the current era has been a whole new learning curve (and those 3 laws just won't bend).
I've learned a bunch and still look forward to absorbing more info as it becomes available..."IE"... learning new things (you never know it all).
I'm still not speechless obviously... But to be honest... all jokes aside, I honestly would never have thought a 750 watt sub wold get so nasty in any install... I'm not speechless just close to it after having 2 12's on 4K... and to me this sounds better... Oh, it don't dig to 23-24hz but who cares?.. the sheer SPL, clarity, enjoyment, looks I get at stoplights and musicality of this setup is something I really wouldn't have thought was possible from a single 750 watt 15" sub and a set of relatively inexpensive 5.25" components, I thought I'd need 5K and a buncha $$$. As it is on a 3K amp at 2 ohm (subs), and 4 ohm stereo on the highs it's fine on stock electrical and It seems very close to an actual live performance in the impact and realism, and a little loud...very close to what my goals were setting out from the get.
Once again...to state the obvious... I'm gonna stick with this setup for a bit... it's decent.
To all the 1st timers starting out... just do your research, listen to advice (even if it's painful) and learn to DIY your own stuff, the internet/forums can be a powerful tool to assist you.
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