My Z7 MOD
1. Dampening of Earcups and Driver Backing with 3M medical grade tape, skipping the vents and ports
Effect: More Refined, Cleaner and Faster Bass Response. (Sub, mid, and upper bass) Adds to both quality and quantity. (Quantity = to bass lovers delight. Tho the quantity is more than for my taste. But there's a fix on mod#3) There's also Noticeable separation of frequenciesthus preventing bleeding of bass to the mids. Mids more pronounced and improved treble.
2. Spacers on both Earcups Applied
Use: Prevents the cushions to touch and cover the driver housing (partially) thus eliminating unwanted noise. Also creates more space resulting to additional soundstage and airiness feeling to it.
3. Bass Port Modification and Repositioning
Effects: Creates additional airflow chamber to the bass port allowing to a more fine tuning of bass response, bass quality and space. Porting allows to fine tune of bass quantity as well. (The bigger the port = more bass and makes the sound character warmer. The smaller the port = lesser the sub bass and mid bass punch, also making mids a little forward and making the treble more sparkling)
Repositioning of the port and porting to fine tune to my liking trims the bass quantity to my taste also making the treble more sparkle and not harsh and making the sound character more balanced and much clearer mids. Crispier now from a lousy on stock. Vocals on the right spot not too forward nor laid back.
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The Z7 MOD creates positive results in totality. Is it subtle, hell no... big difference (compared to stock Z7) in a positive way.
. The only time the plugs and terminals are not following standards are when you intentionally build it that way yourself. 
....but even if you can, you would be like...Why ? Lol
