The comparison hour happens in the listening room at Oto Audio, Pelgrimsgang 14, 3011 Rotterdam. The room is 28 m², with treated walls. Ines Vermeulen has hosted it since she and Tomasz Wójcik opened the shop in 2012, in what had been a print shop. An hour is 60 minutes. It is free. We hold the room for you once you have booked by email or by phone.
What the hour is not
People sometimes arrive expecting a demonstration, a single piece played at its most flattering level. That is not the hour. We put up to three headphones on the table, or two speaker pairs, and we listen to them against each other. The tracks stay the same. The volume is matched before anyone says what they prefer. If the level jumps when the next headphone goes on, the difference you hear is the knob, and the note is useless. Matching the volume is the whole method. The words come after.
Words and figures
We write sound in words because that is how the choice is actually made. The shop has figures, and they stay on the table: driver size, ohms, grams, watts, sensitivity, the room a speaker pair is for. Those figures are how we keep the eight products honest from one page to the next. They are not a substitute for the sentence you can remember on the way home. Airy and wide, light bass. Close and warm, firm bass. Even and detailed, deep bass. A person can use that sentence on a Tuesday. A column of ohms is what they check once the sentence has already pointed somewhere.
The three headphones
The three headphones show why both belong. The Oto H1 Open is an open-back dynamic headphone, 50 mm, 32 Ω, 290 g, €349. On the table it is airy and wide, with light bass, and it leaks. Any phone or the D2 is enough to run it. The Oto H2 Closed is a closed-back dynamic, 40 mm, 24 Ω, 275 g, €299. It is close and warm, with firm bass, and it leaks very little, which is why it is the one for a phone, for night and for travel. The Oto P7 Planar is an open-back planar, 90 mm, 18 Ω, 420 g, €890. It is even and detailed, with deep bass, and it leaks. It asks for the A10 or the A40. At a matched volume the leak is as obvious as the tone. You notice it when someone else is in the room, or when you take the headphones off and the track is still faintly there. We would rather you notice it here than in a shared apartment.
Amplifiers and speakers
Amplifiers and speakers follow the same rule, with less theatre, because there are fewer of them. The A10 is the desktop headphone amplifier, €420, 1.2 W into 32 Ω, quiet and controlled, Class A, two outputs, the partner for the P7 and the H1. The A40 is the integrated amplifier, €1,290, 2 × 40 W into 8 Ω, relaxed and full, the partner for both speaker pairs, with a 6.35 mm socket if you still want headphones in that system. The D2 is the USB DAC, €260, neutral and low in noise, USB-C and optical in, there to feed the A10 or the A40. We do not score them. We listen for whether the background stays quiet, and whether the A40 still sounds relaxed once the S8 is actually moving air.
The speakers need the room size said out loud. The S5 bookshelves, €780 a pair, are a 2-way pair, 25 mm and 150 mm, 86 dB, open in the midrange, for 10–20 m². The S8 floorstanders, €2,150 a pair, are a 3-way pair, 25 mm, 130 mm and two 165 mm drivers, 90 dB, full range with easy bass, for 20–35 m². Two pairs is the limit in one hour, for the same reason three is the limit with headphones. More than that and the matched level, and the memory of the previous track, start to slip. A study of 14 m² is an S5 conversation. A room of 20–35 m² is an S8 conversation. Lucas Moreau takes the same sizes with him on a placement visit in the Rotterdam area, about two hours, at €120, when the hour in our room is not the last word.
How we tune our own pieces
Tuning our own pieces uses the same room in a different order. We listen, then we measure. The measurement is what fixes a published number so it does not drift between the page and the bench. The listening is what fixes the sentence. Tomasz’s amplifiers, the A10 and the A40, are designed on that bench. The hour you book is not a tour of the workshop. It is the part we can share without asking you to care how a figure was taken.
The shape of the visit
The shape of the visit is short, and we keep it that way. You book, and we hold 60 minutes. You bring your music on a phone, a laptop or a USB stick, or you let us stream. We compare side by side, volume-matched. You decide later. Order from the shop if you already know, or take one headphone home on the 10-day trial. The trial is €25, credited when you buy. It is not a way to borrow the S5 or the S8. Speakers stay a placement conversation, or a courier delivery, the S8 on the same EU rates as everything else: free over €150, otherwise €9.
The room is open Tuesday to Friday, 11:00–19:00, and Saturday, 10:00–17:00. It is closed Sunday and Monday. Walk-ins are welcome when nobody has the hour. The phone is +31 10 555 0142 and the email is hello@otoaudio.example. If you are writing, say which day, and whether you want headphones, speakers, or a single product you have already read about. Bring the music you actually play. We will keep the volume still while the boxes change.