Experience with HFTs


There was a very extensive discussion about Schumann Generators (SGs) over the past week and in some thread I saw a mention of HFTs.

Unlike SGs, HFTs appear to interact with the music in a room similar but opposite of Acoustic Panels purpose. I can’t really put those panels or bass traps in because of my room layout and these appear to be small, and not require electricity, but I can’t understand why I would put them on a speaker- the speaker company should have taken its own acoustic properties into account. Also how would you put them on a wall?

Can your please relay your experience with them positive or negative and what you purchased and total investment? Synergistic Research appears to be a leader with these things. Always looking for ways to improve the sound without breaking the bank.
sokogear
I use the HFT's with some bass corner traps, acoustic panels and diffusers.  You can view it on my virtual system.
I use a few in conjunction with other room treatments. After much experimentation I've settled on six being optimum for my room. I use three on each side of room, perhaps five feet behind listening chair, spread out evenly from top to bottom. I've also tried them at many different locations, didn't work for me. In location I have them add sense of greater spaciousness of room, when in fact my dedicated listening room is already fairly deep, that being 25' length, then opening into kitchen. I don't like them anywhere close to speakers, mids sound less natural, more tipped up. Also, don't like them centered anywhere in room, pulls soundstage unnaturally  forward. I prefer judicious use of these along with other diffusion products, in my case, RPG Skylines cut into quarters placed at first reflection points. More subtle than the HFT's here.
I have been using 20 HFT’s in my system since around June 2021. 20 of these buggers. That makes level 4.  I am enthralled! My sound stage has expanded and moved forward and in some instances is like I have headphones on. Sometimes I need to make sure my surround is not on. My bass is better. More separation of vocal And instruments. This all in 2 channel and no subs. EVERYTHING I throw at my system drops my jaw, regardless of source.

20 is about where I'm at. Two speaker kits plus however many room. This is after years of experimenting with various panels and tube traps. HFT are far more effective than those old school treatments. Plan on adding some diffusers some day but for now I am like you, swimming in it. 

The recommended placement program works great, but within those recommendations they are surprisingly responsive to positioning. Mine were put up in pairs and sometimes one at a time, with each one being moved slightly an inch or three and always noticed a change sometimes surprisingly big. One on the back of my old Talon Khorus speakers went from great to awful by moving a mere 2"!   

The champeen of HFT is David Pritchard, who used to be a quite active poster. He had dozens in his listening room, all over his mom's place, and even in his car!



I used to have so many HFT’s, probably 30+ and many more of my DIY creations.

Until I found the Stillpoints Aperture ll’s. They make the room sound so much more real, the HFT’s sound fake when compared. Though a lot more money, I now have 8 of them. And, I also have 20" ASC tube traps in the 4 corners.

I sold off all of my HFT’s.

ozzy