I’m trying to send audio from my phone to a amp/dac and then to my Bluetooth headphones. This is my first foray into BT, I have over 100 wired pairs.
I'm not even sure if there's any device that can simultaneously receive BT audio from one device while sending it to another device. Just because BT can hook up several devices at once doesn't mean it's like wires.
Practically I want to boost the volume and quality of the Bluetooth headphones that I have coming out of my iPhone. With wired headphones you just use a Line out dac/amp and that over rides the source. Can this be done with Bluetooth ? I have no clue.
No, it doesn't work that way. Not even if you can find a DAC with 2-way BT that can work both ways simultaneously with two different devices (normally it's just betweenBT headsets and one device, like a phone or a computer like with gaming headsets using BT).
BT audio is a digital signal. A DAC is a Digital to Analogue Converter. Even if you can find a DAC that can receive the signal from one device then transmit it to another device,
1. You need to ADC the DACed signal because you transmit BT audio ie digital, sending it to DAC via BT means the DAC will DAC it, so for it to transmit it again it would have to ADC the signal back into digital.
2. If you can even find something like a range extender it would need a DSP, not a DAC, to raise the digital volume in the digital domain, not a DAC that would DAC the signal then ADC the signal back into what a BT transmitter can transmit.
When a wired connection "overrides the source" it's because you either
1. Skip the audio circuit of the host device and transmit the digital audio into a DAC-HPamp or a DAC then into a HPamp.
2. Set the line out on the host device like a DAP which either skips the headphone driver stage or on a modern, compact, efficiency-oriented DAP, just telling the audio chip to output 2V, and that audio chip is designed to have enough power and current for efficient transducers like IEMs without being a full-on amp circuit that can introduce enough noise and distortion nor excessive voltage and thus still function pretty much like a normal line output.
The btr5 and quad 5k are BT recievers, I don’t think they would do what I’m looking for. I hope I explained it correct
If you really want to increase the volume, noise, and distortion - because again this is what happen when you DAC, preamplify, amplify, and ADC the same signal, kind of like using two amplifiers in series on analogue signals - there's a way to do it...but you'll need two devices. At least. First, you need a DAC-HPamp with a BT receiver. Then the second device will be another BT transmitter hooked up to the headphone output of the DAC with the BT receiver. The DAC receives the normal signal and DACs it, passes it onto the HPamp circuit, you crank it up, and the BT transmitter will ADC that louder analogue signal and transmit a louder digital signal.
Alternately, if you really, really, really want to increase the volume, noise, and distortion even more than the first solution, you can use a portable DAC-HPamp with BT (or a desktop DAC with BT) and then hook up the line out to a powerful headphone amplifier like a Fiio Q3 and so you can make the signal much louder, that way you can more easily clip the signal getting to your BT headphones.
If you're not streaming the audio and have your own copies, here's a cheaper (if not free) but time consuming solution: look for an app that can apply Replay Gain when ripping tracks, and then increase the gain there (don't save over the same audio files, save a separate copy for these) for use in your phone. You can still more easily clip the signal, but at least the inherent noise and distortion from DACing and amping then errors from ADCing it on the fly won't be a factor.
Alternately if you have good DIY skills or know one who does you might be able to hack the BT headphones' active electronics and route the output of its audio chip into an output stage with more powerful op-amps. You'll have to strap on a new battery, not to maintain battery life but to provide the voltage needed by the new output stage, and this will be even more difficult to integrate into the original circuit, so you might have a 9V battery sticking out of one earcup or the headband (depends on where the BT circuit is).
How do I improve the sound or boost the volume on my iphone Bluetooth, is it possible ( without getting a new phone) ?
As discussed, the problem is not the phone, and solutions are either editing the files to boost their digital gain or any of the hackey hardware solutions above.
Unless you're in Europe.
IF they regulate BT like analogue outputs on mobile devices in which case you might have to replace both the phone
and your BT headphones. Not necessarily something different, just a different version not intended for sale in Europe.
