Pros:
1) Very good sub-bass extension
2) Great vocals and crisp treble
3) Great clarity and instrument separation
4) Creates a very immersive sound field though soundstage may not be the widest
5) Great fit with the stock silicone tips
6) Great metallic carry box provided in the package
7) Lot of reports suggest this to be very easy to drive
8) A great value for money planar iem
Cons:
1) Midbass may not be punchy enough especially for bassheads
2) Not very comfortable with the stock tips for long term listening though the fit is great
3) Apart from the stylish metallic carry box, the packaging is too spartan. The carry box makes a better display item rather than a practical accessory.
4) Some of the included tips does not even fit for the iem!!
My Setup
DAP: Hiby R3 Pro Saber through 2.5mm balanced port
Stock cable changed for TRN T2 16 core silver plated 2.5mm balanced cable (only because there is no 2.5mm stock cable option provided by 7hz)
Listening Sources: mp3, wav and flac files stored in Hiby R3 Pro Saber, Tidal and Quobuz
The feedback on this iem by BGGAR and the unbelievable impressions of this by Crinacle made me take a leap of faith and purchase the 7hz timeless. Suffice it is to say that, my trust in these reviewers were not misplaced. For about 6 months now, I have been using a Hifiman Sundara on my desktop audiophile setup and have been loving its sound signature. When sufficiently powered ( I am driving the Sundara currently using the Xduoo XA10 Dac/Amp through the XLR balanced port), Sundara has a full sound signature with tight bass, forward and lush vocals and crisp but non-fatiguing treble. The sound stage is also immersive though not the widest by any means.
Running the 7hz Timeless from the 2.5mm balanced port of the Hiby R3 Pro Saber Dap in high gain reminded me a lot about the sound signature of Sundara. Similar tonality with the sound stage taken down a notch but still retaining its immersive quality. I am not sure what gives the Timeless its very immersive sonic qualities despite it being a closed-back iem. I take it to be an overall result of the combination of its sub-bass extension, forward vocals as well as great instrument separation and clarity. Not to mention the crisp and detailed treble. The width of the sound stage is comparable to something like the Fiio FD3 Pro. One can easily feel the musical notes travelling from extreme left to extreme right and vocals taking the central stage in various tracks. However, this simply beats the FD3 Pro when it comes to sub bass extension, instrument separation as well as overall clarity. The only advantage FD3 Pro has over the Timeless is its heavy mid bass punch and those who don't prefer the Harman target or simply prefer sub bass over mid bass may not consider that an advantage as well. Tracks with a lot of instruments and atmospheric sounds work especially great with this iem.
However, this iem though it works great with all genres of music may not be great for everyone. For example, bass heads may want more mid-bass punch. Similarly, those who are fans of a warm and dark sound signature may not appreciate the crisp, forward and detailed treble on offer here. The comfort of this iem is also not the best even though the fit is great.
A small note on design: Many iems in this price range comes with either colorful resin shells (eg: Thieaudio legacy 4 and Mangird Tea) or with fancy metallic face plates (Tanchjim iems). In contrast, 7hz Timeless comes with a minimalist all black coin like design. I personally like this design. However, you can consider it either a pro or a con depending on your aesthetic taste and preferences.
To conclude, this iem is great for everyone who can live with its slightly less mid-bass punch and find its comfort to be good enough. Of course, using a quality equalizer can help as well!!