Here's the full article from Prosound translated from Russian:
Sennheiser HD 400 PRO - professional open-back headphones
Maxim Lyadov
Recently, Sennheiser has focused very seriously on the professional direction and has shown great success there. For example, the
Sennheiser EW-D digital wireless radio system left the best impression on us and amazed us with the amount of modern innovations.
Today we are testing the latest professional Sennheiser HD 400 PRO headphones, which can force the audience in the world of sound production to redefine the attitude towards the Sennheiser brand. These are open-back headphones designed for a wide range of audio applications, from music writing to mixing and mastering.
According to the official representative of the company, the new product opens the PRO line of Sennheiser headphones and is suitable for professionals who need detailed and honest sound, with high resolution, to create sound masterpieces.
From our own experience, we can confirm that in studios, from home and personal to large commercial, there is a huge demand for lightweight, comfortable headphones with the highest quality sound, since in addition to the task of mixing the mix, there are no less important stages of creating music. This is writing parts of musical instruments, selecting timbres from hundreds of gigabytes of sound libraries, editing loops and grooves, selecting and adjusting the desired effects, playing various electronic musical instruments, rough editing of material. All of these steps can take hours, days or even weeks! Sitting and working in a studio isn't always the best option. Creative inspiration, some new ideas, can come to the musician even when he is outside the studio room with monitors.
to the most technologically advanced Neumann .
Since we had one more very successful Sennheiser HD 560S headphones for our personal use, released recently for the anniversary of the company, the premiere of the HD 400 PRO was not a surprise for us. The Sennheiser HD 560S is good for everyone and the sound is great, but it's purely for everyday use. Of course, it can also be used for working with sound, but it is not so convenient. She has a very long cable with a rigid sheath with a "stethoscope effect", that is, the slightest impact on the cable resonates into the headphones. For domestic use, this is not scary, but a professional does not sit relaxed in an armchair like an audiophile, but rather often turns his head while sitting at a table with a PC or laptop, while the cord walks around and hits everything. Therefore, for professional use, the first thing we ordered was a twisted cable and another straight short cable in a fabric braid.
In the case of the HD 400 PRO, there is no need to take such actions - from the box, the user immediately receives both a twisted cable and a straight short one in a soft rubber sheath that is not afraid of shocks - it does not transmit them to the listener. Another plus for the HD 400 PRO is an adapter at the end of the cable, which increases connectivity. In professional equipment, stereo minijacks are equally common, especially in portable recorders and cameras, and full-size 6.5 mm jacks. The HD 560S audiophile headphones have a non-replaceable 6.5 mm cable end, which emphasizes their focus on serious stationary equipment. However, the standard connector for connecting removable cables with rotation locking is the same for all these models. Therefore, it will not be difficult to apply cords from one model to another. So, we really liked the native twisted cable of the HD 400 PRO. We feel it is much better than similar inexpensive third-party options and fits perfectly with the HD 560S.
It is worth explaining the markings of the Sennheiser models. For household lines, it has its own history, for professional ones. They are not directly comparable. The 5XX series has been around for a very long time and is positioned as a mid-range headphone for a mass audience. At the same time, the Sennheiser HD 560S model with the letter S at the end appeared recently and has a completely new, very promising emitter, which is beginning to compete and even outperform the 6XX line in some way. Still, the HD 560S is a mainstream model with simplified ergonomics from the 500 series. Despite the efforts of market segmentation, users greeted the HD 560S with the utmost benevolence and it quickly became a bestseller and the undisputed leader in terms of price / quality. It has been used for a variety of purposes, including professional ones. Perhaps that's why Sennheiser's engineers decided to build on the success and make a dedicated professional model. Although the looks are very similar, we feel Sennheiser has improved something in the HD 400 PRO. And it turned out that the new product is already slightly higher than the HD 560S.
The number 400 in the name of the new PRO headphones should not confuse anyone. Sennheiser's professional models have their own history and naming logic, which does not overlap with household lines in any way. Among the HD 25, HD 200 PRO, HD 300 PRO, the new HD 400 PRO is the flagship of professional models. That is, the numbers 400 in the name do not mean at all that the model is below the 5XX line of household models, and at the price it is quite clear that the HD 400 PRO is higher than all household 5XXs.
Sennheiser HD 400 PRO Specifications
- Acoustic principle: dynamic, open
- Ear Coverage: Full Size
- Frequency Response: 6 - 38,000 Hz
- Kg: <0.05% (at 1kHz, 90dB SPL)
- Impedance: 120 Ohm
- Sound pressure level: 110 dB (1 kHz, 1 Vrms)
- Connector: 3.5 mm (1/8 ") with adapter to 6.3 mm (1/4")
- Weight: 240g (without cable)
Among the official technical characteristics, attention is drawn to the harmonic distortion. It has a record low value of 0.05%, which exceeds this parameter in comparison with the Sennheiser HD 560S and Sennheiser HD 600 household models and is comparable to the HD 660S. Other characteristics indicate the use of a new generation of 120 Ohm emitter with a sensitivity of 110 dB / V.The headphones are very light, the weight without cable is 240 g. The fact that the model is open does not allow using it for monitoring when recording with a studio microphone, but in all other professional tasks, especially when listening to nuances critically, open models are often preferable.
The ear cups are quite standard, the logo is made more neutral here, without a shiny insert. There is no premium and elitism in the model, just as there is no overpayment for design elements. The HD 400 PRO is more of a workhorse for everyday use.
The headband has two pillows with foam rubber and velvet fabric fixed with glue. The design is simple and typical for all Sennheiser models.
Planting depth adjustment is standard. In addition, there is a slight rotation of the cups around the axis. All structural elements are plastic, due to which a very low weight is achieved. Will the structure become loose? Based on the similar design of the HD 560S, we have not lost anything in a year of operation.
Frequency response measurements
The measurements are performed using the RightMark ™ Audio Analyzer PRO software and hardware complex . The measuring stand Brüel & Kjær 4153 - Artificial Ear / Ear Simulator (IEC 60318-1), Made in Denmark, cost about 5,000 euros was used.
The Brüel & Kjær stand effectively emulates the acoustic impedance of the ear up to a frequency of 16 kHz. Frequency response measurements are provided for reference only, you should not guess the sound from them.
Frequency response of Sennheiser HD 400 PRO headphone
Frequency response of Sennheiser HD 560S headphone
The frequency response is very similar, but the mid-frequency range is more linear in the HD 400 PRO. The bass does not have any accents, and its decay is a feature of the test stand, in reality there is no decay at low frequencies. The high-frequency range, where there is a decrease and then a peak in the characteristic, is very similar to the Harman target curve for headphones.
According to the available theoretical and practical data, this Harman curve corresponds to the listener's idea of the equal frequency balance of the recording, to which he is accustomed to listening to speakers in a room. Therefore, one should not be surprised that the frequency response has this form - this is the kind of characteristics that all manufacturers are now striving for in all models of headphones. The example of measuring the HD 560S at the GRAS 43AG stand proves this. The boost in bass at Harman's target curve, by the way, only appeared in recent years, according to a study that young audiences prefer equipment that bass well. All such studies are better treated with a fair amount of skepticism, since the data can change and become more precise over time. So far, it is only clear that the midrange is better perceived when it is linear and does not have any peaks and dips. As for the bass and treble, it is still clear that the headphones there should have something to play with. The shape of such a curve is still a subject of study and discussion, since hearing itself is not linear. For hearing, a straight frequency response line is not a goal, but rather a goal in smoothness of the characteristic change. With an increase or decrease in volume, the edges of the range rise or fall, and such a sound is quite reliable and timbre neutral for the ear.
Sound quality
The sound of the Sennheiser HD 400 PRO headphones is very detailed, with a wide panorama. This sound will appeal to both professionals and audiophiles. First of all, attention is paid to the good elaboration of the middle frequencies. The entire range lies at a glance, the timbre accuracy is very high. However, this increased detail does not tire, since it is not accompanied by any unpleasant distortions or accents. That is, bass and high frequencies do not interfere, do not dominate, but are also audible.
In the high one guesses the brand features that are familiar to everyone from other Sennheiser models. If you choose the models to which the HD 400 PRO are as similar as possible, then the HD 560S will certainly be much closer than the 600 series models. If we talk about our opinion, when we switched from one model to another with a minimum pause, our preferences were on the side of the Sennheiser HD 400 PRO. In turn, the HD 560S is closer in sound to the HD 6XX, has a continuous sound, and plays out HF more calmly. The HD 560S lives up to its audiophile focus and is more affordable. The choice between different models of headphones is often ambiguous and comes down to taste. Since the ideal is unattainable, it is necessary that the chosen model meets the personal preferences of the listener as much as possible.
Although Sennheiser HD 400 PRO are quite loyal to the amplifier, they do not impose outrageous requirements on it, a high-quality sound source is able to better unleash the full potential of this model. That is, the high-quality high-level path for the HD 400 PRO is purely beneficial and the sense from the application is clearly audible.
Note the very light weight of the HD 400 PRO and high comfort during long-term use. Corduroy ear pads are an accurate hit on the target, you don't even think about replacing them. We also really liked the straight soft wire included, which comes in handy for connecting to portable audio sources. Although the already affordable price makes the minimalistic configuration understandable only for the most necessary, we would only wish the manufacturer to provide a case for storage and transportation as an option.
conclusions
Before we started testing the Sennheiser HD 400 PRO professional headphones, we had absolutely no expectations. We could get anything and blame it on a purely professional model, but we got a real gem from the entire range of headphones from the German manufacturer. This is an absolutely serious development that clearly embodies the very latest achievements in emitters. Without a doubt, the headphones will appeal to a very large audience of both professional users and audiophiles. If you've already heard the new bestseller HD 560S, then the HD 400 PRO model can be called a pumped-up professional version, with even more detailed sound and two interchangeable cables included. Sennheiser HD 400 PRO sets a new standard in professional headphones for detail and clarity of sound,
(I think so, because they know your Kennerton trayectory...)
- were the HD 555 and HD 800 (also a Superlux HD 668-B that I found very uncomfortable and gave to my wife). But after trying the Sony Z7s and put again the Senn HD 555 I noticed a lot those "protudings" touching my ears (and after the Z7s pillows I couldn´t stand them anymore...). Also, my HD 555 pads were damaged and I replaced with aftermarket pads that clamped more than the originals (not available anymore).