The Impact is an impressive, high-end IEM from Penon. Its tuning is very well-balanced, with great-quality BA bass, fantastic vocal clarity, without being overly bright or fatiguing. I think the Impact has excellent technicalities, including a natural timbre, smooth transients, a deep soundstage, and great detail retrieval. It also strikes a fine, musical balance between all three frequency bands. The Impact makes an excellent all-rounder and is just as capable of playing hard rock as orchestral arrangements. As good as it is, I wish there were more sub-bass presence and deeper extension, and I could also use a little more note weight in the treble to keep the notes slightly more grounded. This set is truly a joy for those who want an immersive and engaging tuning and for anyone who wants to experience EST treble without the overt brightness.

https://www.head-fi.org/showcase/penon-impact.26317/reviews#review-36542

The Penon Impact is a very balanced, smooth, technical IEM in a gorgeous package. It's got good warmth to the vocals, great details, controlled treble, punchy bass. If I'm going to nitpick, the implementation of the BAs doing bass is probably not the best I've heard. Compared to like the Elysian Diva or the AME Mousa, where it doesn't sound nor feel like BA Bass, the Impact does retain a bit of the BA bass signature. Otherwise, everything is overall very good. As far as a flagship IEM goes, you get an excellent balanced sound signature with detailed mids, energetic yet controlled treble, and an extremely technical sound in a gorgeous gold shell.

https://www.head-fi.org/showcase/penon-impact.26317/reviews#review-36305

The Impact is more adept for analyzing music. I hear more detail and texture in stringed instruments and vocals, all presented with silky smoothness. It also scales up very well with sources and higher volume. At the same time, I think the Voltage is uniquely musical, natural, and engaging. Two flavors of excellence.
The Impact and Voltage are two high-end gems. The Impact delivers impeccable tonality and detail, with an immersive soundstage and excellent bass. The Voltage is energetic and also technically capable, with musicality and DD bass that grips you. If you had to choose between these two, either way you'd win.

https://www.head-fi.org/showcase/penon-impact.26317/reviews#review-35873

Starting with bass - all the visual Scriptures apply texture, slam quality and quantity but more than that has a way of dispersing the base inside the stage that I find really satisfying. Penon just recently popped up on my radar in my IEM journey and I am SURPRISED is not heralded as one of, if not the best point of entry for a TOTL IEM.
Afterthought - I’m not much of a vocal person. I focus on the instruments and the groove however, vocals are perfectly centered and placed forward in the mix. This goes for male and female, so if you are looking for a vocal centric experience I think the impact will impress you there too.
https://www.head-fi.org/showcase/penon-impact.26317/reviews#review-35269

The Impact is powerful and controlled, providing a solid foundation for any genre of music. It set the bass foundation on the virtual stage far and deep and with great accuracy. Compared to the Volts, Impact opted for accuracy and neutrality, with a sense of natural crispness over warmth and musicality coming from the Volts. The Holographic Imaging provides a sense of space and dimensionality that truly immerses the listener in the music - regardless of the scale it renders - the experience is immersive - you'll get lost in the music once you're in the zone. The music will surround you and you will be in a state of trance.

https://www.head-fi.org/showcase/penon-impact.26317/reviews#review-33951