Can you use Holland's 11th Harmonic feature and the Frequency Multiplier feature at the same time? Harmonic is for boosting power and the multiplier is for just generating higher frequencies right?

1. Yes, these can be applied together. The 11th harmonic will be of the multiplied frequency. So if the current frequency is 5, and you chose a Frequency Multiplier of 10, then (5 * 10 * 11 = 550) Hz will be modulated by or added to (5 * 10 = 50).

2. Yes you can use both together and your reasoning is correct.

You have two ways to apply the 11th harmonic.
You can use F2 = F1 x 11 which will create a second simultaneous frequency on Out1 or,
you can use Out2 = Out1 x 11 which will create the 11th harmonic on Out2.

So if you had 10Hz in the frequency list; and a multiplier of 1000, your Out1 would be 10,000Hz

The Holland output frequency would then be 10,000 x 11 = 110,000 Hz

Spooky has a lot of knobs and settings which you can change.
Another way to set a higher frequency is to use the minimum/maximum frequency setting instead of the multiplier - the choice is up to you.

For more details, please check the link:
http://www.spooky2.com/forums/viewtopic.php?f=23&t=6910