Are semi-open or closed back objectively better in any way sound wise?

[Deleted member 3116]

I have never owned a mid/high end closed back headphone but the idea of them is appealing.
Even when things are at their quietest there is still often a lot of ambient noise which impacts listening with open-backs, with a closed back you can get to closer to actual silence, so you have a performance advantage over open-backs, not just making environments that would be too noisy for open-backs more listenable.

Environmental noise is an external factor though, it doesn't really have anything to do with how the headphones themselves actually perform.
The general consensus seems to be that in theory open-back is better...
Is this correct?

Do closed/semi-closed back have any inherent performance advantages?

I think higher low-bass sensitivity could be one but not sure...

There are some high-end headphones which seem like they might use a semi-closed construction at least partially for performance reasons e.g AQ Nighthawk, Beyerdynamic T1 series, In fact there are no or at least very few fully open Beyers

 

[markanini]

Closed headphones store energy in the cup which often shows as group delay issues, with time and frequency impacts. Open headphones radiate the same energy into space. Inherently this gives opens an advantage in some areas like soundstage, and they can be easier to keep the response smoother. Closed headphones do have a leg up in bass, though, where the stored energy can work to your advantage.

I’ve always tried to build closed headphones that sound open but Keep the isolation, and bass, benefits. Of course as soon as you try to communicate the benefits it becomes marketing...

 

[maverickronin]

Do closed/semi-closed back have any inherent performance advantages?

I think higher low-bass sensitivity could be one but not sure...

Besides isolation, more bass is pretty much it.

Open dynamics will always roll off. Planars can stay flat if if the space between the driver and ear is sealed, even if the back is left open.

Getting a Harman style bass boost without signal processing isn't easy unless you go closed or semi closed.

 

[ZolaIII]

It's possible to make closed back hedaphones with superb straight bass and sub bass but they don't make them like that at least not anymore.
Once upon the time in galaxy far, far away Pioneer made Monitor 10 II (76 to 79) hedaphones with such characters tho highs were not the best and those were heavy.

 

[MrPeabody]

A good way to understand the difference is by comparison with speakers. A closed-back headphone is like a speaker driver in a very small enclosure, whereas an open-back headphone is like a speaker driver in an enclosure the size of an airplane hanger. When the enclosure is small, the spring effect of the contained air has to be dealt with by using a driver with greater damping. The only practical way to increase damping is by using a stronger magnet and/or greater length of wire within the gap. The mere fact of increasing the damping means the thing is less efficient, and increasing the magnet strength generally means greater weight, although I would assume that the drivers in closed-back headphones generally use rare-earth magnets. In addition to the need for a stronger magnet, the diaphragm has to be stronger because the pressure difference is greater with the small, closed chamber on one side. This suggests a headphone that is inefficient and maybe a little on the heavy side. With poor efficiency compared to other headphones, the voltage sensitivity will be correspondingly poorer unless the impedance is lower. To make the impedance lower, it is generally necessary to decrease the length of wire in the gap, which is contrary to the need for greater damping, so it is kind of like a dog chasing its tail. In general the impedance will be somewhat high, which means that the sensitivity will be somewhat low.

Low voltage sensitivity shouldn't be a concern when using a good desktop amplifier or even using the headphone output of an integrated amp or receiver, but it can be an issue when the headphone is used with a portable device where the maximum signal voltage to the headphone is limited by the battery voltage. If the decision is made to increase the sensitivity by making the impedance lower, then in addition to the difficulty with dealing with the air spring effect, there can be another concern, depending on the output impedance of the amplifier. It may or may not be an issue with a high quality dedicated headphone amp, but with the headphone output jacks of most receivers and integrated amps there is typically a resistor in series with the output, and with portable devices and computer sound cards the amplifier will be a low-cost class D chip amplifier which will typically have a few ohms in series with the output. This may even be a concern with a costly dedicated headphone amplifier (but it is not a concern with large and costly class D speaker amplifiers, which use a more elegant technique to avoid the high output impedance). Even if the output impedance of the low-cost class D chip chip amplifier is merely a few ohms, this is enough to mess with the frequency response of a low-impedance headphone.