Altering the xover point will alter the sound a lot.

500, what you have, results in a more mid heavy, very "up front' aggressive sound.

This can be very desirable with a straight bass reflex, but the 828's short mid bass horn tends to boost that area too.

Going up to 800 will mellow them a lot. To 1200 even more...but how much is good is personal preference.

An electronic xover can help , play around with crossover points till you get the sound you like, then design your passives for that point...or just stay electronic.

Personally, I will never go back to passives. Never.

And this from someone who insists on never saying never...

Really glad the horn worked out for you, in the old days would have had a spare fram to send, but those days are gone...