Buying New Headphones

[BestBurritoSeller]

I want to buy new headphones and got a budget of around 200 dollars.

So far, the best looking option is the Beyerdynamics dt 770 pro, but it has multiple Ohm ratings: 32, 80 and 250, Iv'e tried to look into it but I couldn't manage to find out my motherboard's output capabillity, (ASUS TUF Z390M-PRO GAMING).

 

A. What possible Ohm ratings can my motherboard drive?

B. Can it drive the Beyerdynamics dt 770 pro 80 and 250 Ohm models?

C. Do you have any recommendations for headphones at the 200 dollars range?

D. Would I get any real benefits from the 80 or 250 Ohm models compared to the 32?

[HenrySalayne]

2 hours ago, BestBurritoSeller said:

A. What possible Ohm ratings can my motherboard drive?

B. Can it drive the Beyerdynamics dt 770 pro 80 and 250 Ohm models?

C. Do you have any recommendations for headphones at the 200 dollars range?

D. Would I get any real benefits from the 80 or 250 Ohm models compared to the 32?

A: - All, there is basically no limit. Some older headphone amplifiers had trouble with low-impedance headphones (like in-ears) but there is no upper limit. However, higher impedance headphones will be driven with less power and might be quieter.

B - Most likely, yes. If you want to use the headphones at home and you don't want to damage your hearing, even 250 Ohm should be loud enough.

D - All three sound slightly different. The 32 Ohm is described as a tiny bit more bassy, the difference between the 80 and the 250 Ohm models is practically inaudible. Every reported "difference" might be just manufacturing variations. I think the 32 Ohm and 80 Ohm model will suit your a use at home with your computer.

[BestBurritoSeller]

10 minutes ago, HenrySalayne said:

A: - All, there is basically no limit. Some older headphone amplifiers had trouble with low-impedance headphones (like in-ears) but there is no upper limit. However, higher impedance headphones will be driven with less power and might be quieter.

B - Most likely, yes. If you want to use the headphones at home and you don't want to damage your hearing, even 250 Ohm should be loud enough.

D - All three sound slightly different. The 32 Ohm is described as a tiny bit more bassy, the difference between the 80 and the 250 Ohm models is practically inaudible. Every reported "difference" might be just manufacturing variations. I think the 32 Ohm and 80 Ohm model will suit your a use at home with your computer.

First of all, Thanks!

In relation to B., is there any way to actually check it? i've searched in many places, but couldn't find any useful information about output voltage or something that will help me understand if my motherboard matches the headphones.

[HenrySalayne]

Generic headphones used on a PC are somewhere in between 16 to 100 Ohms. You should expect something with average sensitivity (like the 770s) to do just fine. The difference between 32 Ohms and 80 Ohms is only a few dB. Or you could measure the output voltage. But I wouldn't overcomplicate it. Either check similar headphones (with known specs) you have laying around or just go for it and buy the 32 Ohm version.

 

[Spuriae]

A: Rating an amplifier's output in terms of how many ohms it can drive is electrically wrong, and it's sad to see so many companies doing it nowadays. How loud a headphone will get is determined by its sensitivity/efficiency (how much sound pressure it produces per unit of power input) and impedance (what ratio of voltage to current the headphone requires). An amplifier will usually have a maximum output voltage, a maximum output current, and an output impedance (ideally zero, this value describes the amplifier having to drive a load of its own before power gets to the headphone). The impedance of a headphone determines which limit the amplifier will hit first (its voltage or current limit); extremely high or low impedance values can cause an amplifier to run out of one far sooner than it runs out of the other. For most headphones with reasonable impedances, the sensitivity is far more important than the impedance when determining how loud a headphone will get.

 

B: The ALC1200 Realtek codec is rated for 1.1V(rms) voltage output into 32Ω on its own. I am not 100% sure about whether the S1200A is just a relabeled ALC1200, what the unloaded output voltage is, or how Asus designed their circuit on that particular motherboard. Current will generally be limited by the output impedance. I cannot find measurements of the output impedance on this particular motherboard. However, MSI and Gigabyte tend to use 75Ω resistors in the path of the headphone output. Furthermore, the TUF X570 Plus also uses the S1200A, and using measurements from here corresponds almost exactly to a 1.3Vrms output unloaded with a 75Ω series output impedance. These theoretical values are fairly close to measured values I've seen before, so I will use them as if they were the real values.

 

Note that for the math below I will be using ideal (theoretical manufacturer spec) values. The actual values will slightly differ from these, but not enough to change the conclusions.

For each of the common DT770 impedances, assuming a 1.3Vrms source with 75Ω output impedance, I calculate the motherboard output power over the headphone as:

• 32Ω: 0.389V, 12.2 mA, P = 4.75 mW
• 80Ω: 0.671V, 8.39 mA, P = 5.63 mW
• 250Ω: 1 V, 4 mA, P = 4 mW

All three models of the DT770 are rated for 96 dB/1mW. Final loudness can be calculated using (dB SPL) =  (dB/1mW) + 10 * log₁₀ (P). This gives:

• 32Ω: 102.8 dB SPL
• 80Ω: 103.5 dB SPL
• 250Ω: 102 dB SPL

Based on the 75Ω output impedance, this is somewhat expected. Headphones with impedances close to 75Ω are the loudest, but since all of the models are relatively close to 75Ω (on an absolute scale), there isn't much difference in final loudness. Also worth noting is that headphone sensitivity, which can differ by tens of decibels among popular headphone models, has a much larger impact than impedance on loudness.

 

If an ideal amplifier with zero output impedance and infinite output current were assumed, then the highest impedance headphone would be the hardest to power by a large margin. In practice headphones and amplifiers tend to be far enough from ideal that this rule of thumb often doesn't work.

 

Now, these are peak values (how loud it would be if the headphones played a max volume sine wave). Actual music tends to be about 15dB quieter than the peak value on average. If you listen to music at an average level of about 85dB or lower, then the headphones should get loud enough for you on your motherboard. If you use software effects like EQ or listen to particularly high dynamic range music, the practical output level may be a bit lower. For me personally, this is adequate; regularly listening at higher levels can lead to hearing loss over time.

 

C: There are a number of good open-backs at $200: HD650, K612 PRO, HD58X, HE400SE. Not knowing anything about your sonic preferences, I don't really have any specific recommendation. If closed-backs are a necessity then the DT770 is a decent place to start.

 

D: Tyll did a comparison of all three versions of the DT880 with some measurements back in the day. If you are using a high output impedance amplifier, then the lower impedance models will have more bass but somewhat lower quality sound overall due to ringing from reduced damping. If you are using a low output impedance amplifier, then the differences are likely within manufacturing error margins and personal preference (the higher impedance models may still on average perform negligibly better because the drivers have tighter tolerances). Motherboards are usually high output impedance, so I would recommend going with the higher impedance headphone.