Schatten HFN passive in Composite Acoustics Ox

[beanpole]

First off I wasn't sure if this should go here or in carbon fiber but decided it is an installation question. I finally removed the LR Baggs Stagepro Element that came installed. I never liked the sound of it and am thinking of installing a passive Schatten. Leaning towards using the putty since the carbon weave surface is a little rough. Any thoughts or ideas out there on this. An added benefit is in I have a sound hole where the barn door used to be.

[jonfields45]

I've installed HFNs in three RainSongs. They seem to work as expected. I used tape but it was important to put some significant pressure on each leg of the HFN to securely seal the tape to the top. In my case one of the three HFNs was not perfectly flat. The underside of a RainSong is pretty smooth and flat. I've not owned a CA in quite a while, but my recollection is the underside of the top is also similarly smooth and flat for the models with regular bracing. The integrated bracing (like the Cargo) might be best done with putty. Putty is much more forgiving for bridge plate non planarity (and none are truly flat in any guitar).

[beanpole]

The surface is flat but not exactly smooth so I think I would go with the putty. It looks to be a somewhat close fit due to some braces if I have the right info on the size of the pickup. 2.75" x 1/4". That should make it. Appreciate the input.

[jonfields45]

The underside of a RainSong top is also raw CF weave and not exactly smooth. Some people like the sound of putty better. I've not tried it.

These pictures are from an early install. That poster tape is definitely too strong for putty and not great for tape. I did later installs with only two little patches of poster tape.

[beanpole]

Thanks for the pictures Jon. It looks like the texture of your Rainsong is similar to my CA so I think I will go with the tape first. When you said two patches did you mean just the outside feet? I thought I remember seeing somewhere that some folks did that. I guess I will stop by the local links and beg a few golf tees.

[zeeway]

I installed the HFN Scatten passive in my Emerald X20, which looks remarkably similar to those Rainsong interior shots (except no braces in X20). I smoothed the interior with some light sanding...was 200 grit sanding block, as I recall. After cleaning out the sanding dust, I did a putty install. Sounds pretty good through a Fishman Artist....with mids and lows turned down. I also use a RedEye preamp, and I need less EQ in those situations.

I can’t say it sounds super-great, but IMHO, it is much better than the Baggs Element and the K&K pickups that were previously in that guitar.

[jonfields45]

This is my advice as an engineer (and manager) who was responsible for all package design engineering (other stuff too) for a $2B annual revenue semiconductor company for 5 years of his career, do not sand CF composite.

To clarify about using less poster tape on my jig, instead of putting the tape on the jig parallel to the HFN, I went perpendicular with a piece of poster at each end of the HFN. That 3M poster tape is really a pretty strong adhesive and you want the tape or putty to win when you pull out the jig.

A better solution might be to use a small bit of putty at each end of the HFN to attach the HFN to the jig.

[beanpole]

Thanks folks for the input. I have a clear idea now of how to proceed.