K... I'll be speaking from my experience between a Blaze7, a D-Activator7, and a regular D-Sonic; not necessarily to convince but to educate their tonal differences.
Out of the 3, the D-Sonic's easily has more thump and growl for that "tight low end crunch". However, it's probably too bassy to play thrash riffs.
D-Activator7's are technically the opposite of the D-Sonic; they're brighter while the tone of the strings are amplified rather than the pickup's tone being amplified producing a crunch that's EMG-like. They definitely have a tighter crunch than a D-Sonic, but not as thumpy. Both have a "modern" voicing to it which may or may not be a deal breaker.
And of course, the Blaze7 is the pickup tone used by many players who've kept their UV's stock, not as "hot" but articulate voicing I personally like the D-Sonic as it's a versatile hi-gain and clean bridge pickup. Someone posted a clip of a DS7 before and it sounded sick...

Reg

 

Depends on how noisy your rig, or home's wiring is. The D-Sonic 7 is a noisy little pickup, but the tone is great for clear metal riffing.

You might want to hop on over to sevenstring.org and read up a bit there. Pretty much every 7 string pickup has been discussed over there, though the SD Blackouts have made a big splash as of late.

 

Between the three, it really depends on what kind of stuff you plan on playing. The Blaze 7 I find to be the best if you do a lot of lead playing, but if you like to do more riffage, then the D-Sonic 7 or D-Activator 7 is the way to go. Probably the best description of the difference between the D-Sonic-7 and the D-Activator-7 is that the D-Sonic 7 is good if you want to play metal, but if you want HEAVY metal, then you'd want the D-Activator 7.

(If you want to give actives a try, I personally like the EMG 707 or EMG-81-7 with the 18v mod)

 

x2n-7

 

D-Activator. Those pickups have a lot of high end, so if it's a little too much treble for your tastes, then try a 250 volume pot. That should do the trick and should sound fantastic in a Basswood bodied guitar: tight lows and a lot of punch.

 

D-Activator. Those pickups have a lot of high end, so if it's a little too much treble for your tastes, then try a 250 volume pot. That should do the trick and should sound fantastic in a Basswood bodied guitar..

damn i assume this guy is playing a 7 string cuz he wants to shred

do u now??

a 250k pot on a high gain pickup tottaly goes against the concept..

u want a high gain responsive, tonal pickup, that functions properly...well, you going to be reducing ur responce, and ur dunamic with a lower pot value every time u go lower

id say use a 1 meg volume and a 500k tone with a .044 cap on the tone

rule of thumb with high gain pickups, use a higher volume pot then a tone or it kills the dunamics of the pickup completely!!!!!

but if u want a over the top thrill chimer us a d activator, i like the x2n its a more solid compressed signal that have awesome dynamics for pick responce and playing responce