| Maxtaf |
The variant that I have seen and like is as follows:
Weird Words (Su): At 6th level, a sound striker can use his voice as a weapon. For one round per day per class level, a sound striker can use his voice as a weapon, lashing out with up to 1 potent sound strike per attack action he has available. Each strike deals 1d8 points of damage plus the bard's Charisma bonus, has a threat range of 1, and has a max range of 30', after which the sound is not intense enough to cause damage. The bard chooses what type of damage each strike deals (bludgeoning, piercing, or slashing). These rays count as magical weapons. While not explicitly a Bardic Performance, this ability does replace suggestion.
This limits it to a number of times per day, and further limits it to a single strike, unless the bard does not move and takes a full attack action. It also is reasonably in line with weapon damage (die plus stat mod for each strike), and is below even dagger range, not to mention bow range. It also allows it to be used as a weapon, not interfering with Bardic Performance. As Bardic Performance is more spell-like abilities, not weapons or attacks, this preserves the spirit a bit better.
I think this is a reasonable alternative. It makes it a weapon, pure and simple. If you still think it's too much, take note of just how much damage an archer can do at 30'.