As you know we have great headphone amplifier projects like KORG Nutube B1, Noir HPA, Whammy HPA etc. Is it possible to make similar quality one wireless (Bluetooth) headphone amplifier project on a commercial headphone? Is it possible to make a product better than the Apple Airpods Max? Or do you know already made one ? Could you share?
Best Regards
Best Regards
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Not sure about thd wireless electrostatics as I never heard them bu I worked with the guys who did some of them. Here's a first google return: https://www.headphoneauditions.nl/product-categorie/headphone-over-ear/bluetooth/
Hey, I want to clarify some things.
Modern wireless, noise cancelling headphones are somewhat complicated and rely on DSP. Replicating that with DIY methods is difficult.
Lets start with wireless connection and amplification. DIY audio gear is often very high quality, much better for the price than new commercial products. However this performance is not for free. The usual strategy used by DIYers is to reduce features and simplify functionality to bare bones, for example an amp with a knob. You can get a lot of performance for your money that way. Because of that DIY gear is often made of discrete parts and eat a lot of energy. DIY gear is generally inefficient, because efficiency is the best resource to trade for sound quality A-class amps and all that. All this goes against high quality battery operated headphones. Generally the recipe for great, modern headphones is lightweight, efficient, small. I'm afraid DIY has nothing on that. With headphones there is also a problem of impedance. Unlike loudspeaker drivers, headphone impedance varies greatly and high quality headphone drivers often present wildly different load on the driving circuit.
Noise cancelling is one of the worst cases. Noise reduction is limited in bandwidth. Passive noise isolation is in conflict with comfort bundled with sound quality and looks. This is why you don't see folks running around with earmuffs. Even then, passive noise isolation works only for the upper frequencies. In earmuffs it reaches as low as 200Hz,. In earplug-style, deep insertion IEMs like Etymotic it reaches 100Hz. Unfortunately even in these extreme cases attenuation at these frequencies is unimpressive. In reality passive noise attenuation should be considered efficient from 1kHz up.
Active noise cancellation is still under development, so it can get better, but generally it's also bandwidth limited although this time it works with low frequencies. Peak efficiency of ANC is at 200Hz and then it fall down to about 3kHz. So the best isolating headphones have both ANC and passive isolation.
Currently the best isolation is achieved by Apple and Bose and Sony in their expensive models. These headphones don't sound very good, although mostly the reason may surprise you. They don't sound well, because of a certain phenomena that is present in the distribution system. To put it short high quality sound is not as marketable as low quality sound. If you want to hear clean sounding headphones you're better off getting cheaper headphones like JBL Tune 710. They don't have ANC, but they have bluetooth and balanced sound. The truly audiophile option is Focal Bathys and you might want to check the price on this one.
ANC is currently achieved in two ways: feed forward method and feedback method. Feedback is similar to the motion feedback in loudspeaker woofers, except it's achieved with a microphone. A mic capsule is placed in front of the driver, inside the earcup. It's used as a sensor for headphone's amplifier's feedback. Because of a severe delay, it can be used only for the lowest frequencies. The benefits are that, together with noise, it also reduces distortion in bass. Distortion is not very important for sound quality in headphones, but it makes a small difference.
Feed forward works with a microphone outside of the earcup, where the output of that microphone is then mixed with the signal. The benefit of feedforward is low delay, which is why it can work up to kHz region. The biggest downside is wind noise, which gets added to the mix. Feed forward can also add some noise if the mic capsule is low quality.
A high quality ANC headphone needs to have both feedback and feed forward circuits. It's then called hybrid ANC and it's implemented using a dedicated DPS chip, often some highly integrated, low energy codec chip, with not so great sound quality, but good battery life and low footprint.
Current trend is also to have special features such as transparency mode,where the signal processing is separating speech from the ambient noise and adding it to the mix. All that needs to be used in your DIY product if you want it to be comparable to $500 hi-tech headphones.
Im also interested in audiophile wireless headphones, although I'd gladly trade the ANC functionality for good sound and that last thing is certainly achievable today with DIY wired headphones.
Modern wireless, noise cancelling headphones are somewhat complicated and rely on DSP. Replicating that with DIY methods is difficult.
Lets start with wireless connection and amplification. DIY audio gear is often very high quality, much better for the price than new commercial products. However this performance is not for free. The usual strategy used by DIYers is to reduce features and simplify functionality to bare bones, for example an amp with a knob. You can get a lot of performance for your money that way. Because of that DIY gear is often made of discrete parts and eat a lot of energy. DIY gear is generally inefficient, because efficiency is the best resource to trade for sound quality A-class amps and all that. All this goes against high quality battery operated headphones. Generally the recipe for great, modern headphones is lightweight, efficient, small. I'm afraid DIY has nothing on that. With headphones there is also a problem of impedance. Unlike loudspeaker drivers, headphone impedance varies greatly and high quality headphone drivers often present wildly different load on the driving circuit.
Noise cancelling is one of the worst cases. Noise reduction is limited in bandwidth. Passive noise isolation is in conflict with comfort bundled with sound quality and looks. This is why you don't see folks running around with earmuffs. Even then, passive noise isolation works only for the upper frequencies. In earmuffs it reaches as low as 200Hz,. In earplug-style, deep insertion IEMs like Etymotic it reaches 100Hz. Unfortunately even in these extreme cases attenuation at these frequencies is unimpressive. In reality passive noise attenuation should be considered efficient from 1kHz up.
Active noise cancellation is still under development, so it can get better, but generally it's also bandwidth limited although this time it works with low frequencies. Peak efficiency of ANC is at 200Hz and then it fall down to about 3kHz. So the best isolating headphones have both ANC and passive isolation.
Currently the best isolation is achieved by Apple and Bose and Sony in their expensive models. These headphones don't sound very good, although mostly the reason may surprise you. They don't sound well, because of a certain phenomena that is present in the distribution system. To put it short high quality sound is not as marketable as low quality sound. If you want to hear clean sounding headphones you're better off getting cheaper headphones like JBL Tune 710. They don't have ANC, but they have bluetooth and balanced sound. The truly audiophile option is Focal Bathys and you might want to check the price on this one.
ANC is currently achieved in two ways: feed forward method and feedback method. Feedback is similar to the motion feedback in loudspeaker woofers, except it's achieved with a microphone. A mic capsule is placed in front of the driver, inside the earcup. It's used as a sensor for headphone's amplifier's feedback. Because of a severe delay, it can be used only for the lowest frequencies. The benefits are that, together with noise, it also reduces distortion in bass. Distortion is not very important for sound quality in headphones, but it makes a small difference.
Feed forward works with a microphone outside of the earcup, where the output of that microphone is then mixed with the signal. The benefit of feedforward is low delay, which is why it can work up to kHz region. The biggest downside is wind noise, which gets added to the mix. Feed forward can also add some noise if the mic capsule is low quality.
A high quality ANC headphone needs to have both feedback and feed forward circuits. It's then called hybrid ANC and it's implemented using a dedicated DPS chip, often some highly integrated, low energy codec chip, with not so great sound quality, but good battery life and low footprint.
Current trend is also to have special features such as transparency mode,where the signal processing is separating speech from the ambient noise and adding it to the mix. All that needs to be used in your DIY product if you want it to be comparable to $500 hi-tech headphones.
Im also interested in audiophile wireless headphones, although I'd gladly trade the ANC functionality for good sound and that last thing is certainly achievable today with DIY wired headphones.