Trenner & Friedl SUN

Surprise2 (surprise surprise!)

[Trenner and Friedl SUN]
[Italian version here]

Product: Trenner and Friedl SUN - two-way bookshelf loudspeakers
Manufacturer: Trenner & Friedl - Austria
Approx. price: 2590 € (pair) [possible variations depending on finish]
Test sample supplied by: Yacht Hifi - E-mail:
Reviewer: Lucio Cadeddu - TNT Italy
Reviewed: July, 2018


Back in November 2012 I reviewed the Trenner&Friedl ART, a compact two-way minimonitor that surprised me with its big, dynamic and extremely involving sound, despite its diminutive size. It was rather expensive (>4000), but amazingly musical. Now, time has come to review the smallest speaker made by the Austrian firm, here comes the SUN! Before I start, for more infos on Trenner&Friedl, let me redirect to that review and to my interview with Andreas Friedl.

Manufacturing and finish

The Trenner and Friedl SUN is an extremely compact-size two-way bass reflex loudspeaker. Though - at a first glance - you might think it's equipped with a full-range driver, think again. This loudspeaker relies on the virtues of a 4.7" coaxial driver, the excellent Seas L12RE/XFC. Like other loudspeakers in the T&F catalogue, even the SUN cabinet is claimed to be sized following golden ratio proportions (actually, it is not). Finally, the bass reflex port is rather unusual, being designed as a system of four small ports drilled in the back of the speaker.
Internal wiring and binding posts are by Cardas, while the crossover is handcrafted by Mundorf Germany, using only high grade components.

[Trenner and Friedl SUN - crossover Mundorf]

Tech specs

[Trenner and Friedl SUN - Seas L12RE/XFC coaxial driver]


These speakers are available worldwide thanks to a quite large network of official dealers.

Surprise2 (surprise surprise!)

Small loudspeakers have never been my regular cup of tea. Hyper-small loudspeaker like this one are literally mind-blowing to me. How can they sound any good? To make things even worse, these SUN seem outrageously expensive. Well, the proof is in the pudding, as they say, so let's leave prejudices at the door, conveniently far from the listening room.

I know the first question that comes to mind when dealing with such a diminutive speaker is “What about the bass” Well, this has been the first “surprise”. Claimed frequency response is 55 Hz (albeit at -6dB) but what these speakers are capable of goes beyond the numbers. The amount of bass is simply jaw-dropping, especially when you look at these tiny boxes. Close your eyes and you can easily imagine a much bigger speaker sounding in front of you. You start wondering where the subwoofer has been hidden. It is a deep, powerful and clean bass range, despite the size of the driver and of the cabinet.

This surprising bass makes the tonal balance of the Sun neutral, more or less like I experienced with the bigger brother ART. Do less expensive bookshelf loudspeakers, with larger cabinets and bigger woofers, play better? Yes and no. You can get “more” bass, perhaps (and not always), but definitely not better quality. Are there limitations? Of course there are! Especially when played very loud the bass seems a bit late, when compared with the rest of the audio range. This slowness can be detected, depending on the musical program, even at lower listening levels. This is the price to pay for an extremely extended bass from a small woofer inside an even smaller cabinet. It's a “give & take” game: you earn something, you lose something. However, the balance of pros and cons that the designer has been able to achieve is simply amazing.

The second “surprise” comes from the mid-high range. This speaker uses a coaxial driver: this solves many of the problems of a conventional array of woofer and tweeter, but it isn't perfect either. Hence, I was expecting some trace of confusion here and there...and I was damn wrong. These babies are so coherent, transparent and crystal-clear that every recording is unveiled in its true essence. Though slightly warmer than the bigger ART, the Sun sound extremely musical and introspective. Voices are always natural, undistorted and extremely easy to follow. Male voices might sound a bit thin at times, but you won't notice it unless you compare the Sun to much bigger and far better loudspeakers. With choirs it becomes extremely easy to detect male and female parts: you can decide to hear them as a whole or follow male and female parts independently.

Musical instruments as strings are simply outstanding: very rich in harmonic content, metallic as they should be when required, while pizzicatos are a joy for the ears. Drums and percussions are lively, with good energy and impact, even when one forgets the size of the speaker. Considering these are some of the smallest monitors in the market the result is literally breathtaking.

Overall, the level of distortion is extremely low. This could be the result of several factors, but certainly the quality of the cabinet has some influence here, together with the care of manufacturing of the crossover network. This absence of colouration makes the music flow naturally and effortlessly, exactly like it happened with the ART. A kind of family imprinting.


[Trenner and Friedl SUN - rear view]
Cardas binding posts & the unusual reflex “ports”

A 4.7" midwoofer in such a small cabinet can be impressive but it can't play miracles. The sensitivity is extremely low, at 82 dB/w/m. This means they require a good amount of power to sound loud and even to “come to life”. Because of their low distortion levels you could be eager to turn the volume up until you reach insane levels. Do not forget the drivers are small and though the Seas unit seem to be able to deal with 200 watts peaks (and 50W RMS) please be careful as with heavy bass musical programs the midwofer can easily reach the bottom of its physical limits. Moreover, there's a huge amount of air flowing from the rear ports and these, at certain frequencies, might produce noise.
The sound, overall, appears highly dynamic and lively, despite the size of the driver. This contributes to the “big sound” these speakers can deliver. Attacks and decays are correct, just sometimes slow in the bass when playing highly demanding bass-rich tracks.

Thanks to the extremely low listening fatigue these speakers can play virtually anything, from rock to pop, classical and jazz, you name it, no preferences of sort. They help any music come to life.

3D soundstage

These speakers are so small they can easily sit in the palm of your hand. Moreover, they are equipped with a coaxial driver. These two factors, paired with an extremely rigid cabinet, make 3D imaging a joy for the ears. The virtual soundstage is huge, stable and perfectly focused behind the speakers. Width and depth are excellent, while the height depends, strongly, on the height of the stands.

Once you sit in the “sweet spot” you can enjoy a truly amazing virtual stage, where instruments and players appear absolutely stable and realistically sized. The sound of the recording venue is reproduced with extreme realism. If you move from the sweet spot the result deteriorates rapidly, though.

Placing the SUN on anything different from a good pair of speaker stands is a no-no. If you don't experience the kind of 3D soundstage I've described you're doing something wrong with speakers installation. Place them far from nearby walls and parallel one to the other. No toe-in required, in my opinion. Of course, as you can easily guess, when everything is set-up “right”, these speakers literally disappear.

[Trenner and Friedl SUN - pair]

Some advice

As said: good speaker stands are mandatory (height >70 cm). Avoid placing them close to side and rear walls. You can decide to reduce rear wall distance in order to boost bass output, but there's a limit you can't exceed, otherwise the incredible virtual image gets compromised. And it would be a shame.
Break-in, as usual, is strictly necessary, as the small coaxial unit needs some work-out before performing at its best.
Powerful amplifiers seem mandatory as well, considering the extremely low sensitivity. The low nominal impedance (4 Ohm) might help exploiting some extra watt, but do not go below 30 watts per channel. Being the Sun on the neutral side you can use warm sounding ancillaries or lively components, following your personal taste. Needless to say, the quality of sources and amplifiers can't be sacrified. These babies need and deserve the best you can afford.


Manufacturing and finish.
At 2,590 €/pair there's nothing to complain, except the...price tag! Manufacturing and finish are top class. I'm not sure this price can be 100% justified, after all those Seas drivers street price is, more or less, 300. Add the cost of the crossover, the rest is just a small cabinet.
The Cardas binding posts can accept bare wire, spades and some kind of bananas. Someone might find using bananas a bit trickier than usual, you might need to use banana/fork adapters.
These speakers belong to a league of their own, because of price, technical solutions and size. For sure, these are the most impressive speakers I've ever heard with relation to their size. Bass output is amazing, though bass notes are sometimes slower than they should be. Some air flowing noise can be detected from the rear ports, when playing bass-heavy tracks at loud listening levels.


In my previous review of the ART I wrote “Are they expensive? Yes, definitely. Too expensive? Maybe”. These Sun might appear even more expensive. If you twist my arm, I'd say the ART do sound better, in my opinion, but there's a +1000 difference. After all, if you're in the market for a small loudspeaker and you're ready to cash out 2600 for it, spending another 1000 extra shouldn't be a problem, unless you have severe room limitations and you can't find the right place for a pair of ART. However, the Sun belong to such a small niche of the market...and in that niche they rule. Period.

© Copyright 2018 Lucio Cadeddu - -