Dumbest noob question ever?

[oysterman]

Hi,

I'm not that au fait with car audio, though I understand a little.

I'm looking to get rid of my HU altogether with audio coming from a mini pc or a pi with a DAC instead.

Question: can I plug these audio sources directly into the amp without issue? What is the HU doing other than serving as a conduit for audio, CD and radio? I don't need these, I just want to plug my audio sources in directly.

I'm thinking of getting the Alpine F300. I have 4x40 jbls in one zone and 2x 60w cadence and 2x 100w polks (3ohm) in the second region. Worked fine switching between the two regions for the last ten years but HU getting old and faulty (Alpine CDA, supposedly 4x 60w but not really of course).

Also noticed the F300 has multiple aux in but each one is labelled separately, which I don't understand. Should be Aux 1 L & R, Aux 2 L & R. Instead they're labelled ch 1,2,3,4, like four mono inputs.

Any comments on either issues here?

Thanks

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[THATpurpleKUSH 5,000+ posts]

Stop using peak power numbers.

 

[Jeffdachef 5,000+ posts]

Hi,
I'm not that au fait with car audio, though I understand a little.

I'm looking to get rid of my HU altogether with audio coming from a mini pc or a pi with a DAC instead.

Question: can I plug these audio sources directly into the amp without issue? What is the HU doing other than serving as a conduit for audio, CD and radio? I don't need these, I just want to plug my audio sources in directly.

I'm thinking of getting the Alpine F300. I have 4x40 jbls in one zone and 2x 60w cadence and 2x 100w polks (3ohm) in the second region. Worked fine switching between the two regions for the last ten years but HU getting old and faulty (Alpine CDA, supposedly 4x 60w but not really of course).

Also noticed the F300 has multiple aux in but each one is labelled separately, which I don't understand. Should be Aux 1 L & R, Aux 2 L & R. Instead they're labelled ch 1,2,3,4, like four mono inputs.

Any comments on either issues here?

Thanks

actual audio processing and tuning.

Most modern head units have a Quality 24 bit dac way superior to whatever is in your mini pc with a dac. Why? because it allows for tuning. You cant use headphone logic for car audio. Just buying a dac wont help much of anything in the world of car audio because a car is not a headphone. Its a noisy environment plagued with phase cancellation, surface reflections and overall poor audio acoustics.

What the head unit does is actually have crossovers, and slope adjustments, time alignment/correctoin along with 13 band EQ or higher, along with having a STRONG pre-out voltage which is extremely weak with pc/pi+dac combos and there's 3 pairs or RCA outputs. Some pioneer head units can run active network mode which is a much more advanced setup where you literally assign midranges and tweeters to do their own jobs and getting rid of passive crossovers from components completely so one pair of RCA will handle midrange, one will handle tweeter and the last pair will handle subwoofer frequencies.. Other standard setups will be front, rear and subwoofer. So yeah you need dedicated RCA channels than handle proper frequencies and puts out strong signals for those frequencies.

All is necessary and quite frankly your idea will result in a complete mess because you also lose the ability to time align as well, if you dont know what that is, just look at how your speakers in the car are positioned, your left side is much closer to you so the sound waves reaches your ear before the right side. Time alignment delays the signal so every speaker/midrange/tweeter reaches your ear at the same time creating a perfect centered sound stage which replicates what you can achieve in ideal home audio and headphone situations.

That amp is usually 1&2 front and 3 and 4 rear or 1&2 tweeter 3&4 midrange its both stereo left and right.

So yeah Head unit for car audio, absolute must. No ifs ands or buts about it. Its a lot more complicated then you can ever expect when you want a properly done setup and its not possible without a good head unit and head units nowadays are FAR more advanced than whatever you had 10 years ago. UNLESS you just want unintelligible noise that has some resemblance of music then yeah go ahead with your original idea and prepare a lot of RCA to aux and RCA y splitters.

 

[oysterman]

Thanks for that. I suspected the HU was doing a whole lot more so that's a great explanation. I should mention that this is actually a boat install, not a car. Not sure how much difference that makes. My boat is 43ft in length, so the saloon is probably 4m x 4m, whilst the cockpit is open. It's normal to have a car system in this environment because of the 12v thing, but this is why I was thinking of doing away with the HU. My environment is more like a small room or an open space than it is a car.

 

[oysterman]

Stop using peak power numbers.

I did acknowledge that the HU claimed numbers aren't realistic, but I've no idea what the RMS rating is, sorry.

 

[Jeffdachef 5,000+ posts]

Thanks for that. I suspected the HU was doing a whole lot more so that's a great explanation. I should mention that this is actually a boat install, not a car. Not sure how much difference that makes. My boat is 43ft in length, so the saloon is probably 4m x 4m, whilst the cockpit is open. It's normal to have a car system in this environment because of the 12v thing, but this is why I was thinking of doing away with the HU. My environment is more like a small room or an open space than it is a car.

you'll still want seperate volume/output controls for the saloon/ cockpit and some sort of bluetooth streaming to make life easier and switch songs anywhere on the boat. Still needs tuning especially if you just have run of the mill speakers. I still dont see the other option coming anywhere close to as viable as a dedicated head unit.

 

[oysterman]

Don't need BT as my music is on HD but understand your reasoning for the HU. I guess my next question should be what HU? What's good these days? Don't need radio, don't need CD, don't need BT. Just something that handles your points above, and maybe a remote. Guess even power isn't so important if I were to add an amp? The CDA that I have was expensive at the time and whilst it's served me well I always thought it was over-speccd for my needs. This is why I'd come round to the idea, albeit incorrectly, of getting rid of the HU. I don't need any of the features on an HU, except for the reasons you point out.

 

[los33]

Don't need BT as my music is on HD but understand your reasoning for the HU. I guess my next question should be what HU? What's good these days? Don't need radio, don't need CD, don't need BT. Just something that handles your points above, and maybe a remote. Guess even power isn't so important if I were to add an amp? The CDA that I have was expensive at the time and whilst it's served me well I always thought it was over-speccd for my needs. This is why I'd come round to the idea, albeit incorrectly, of getting rid of the HU. I don't need any of the features on an HU, except for the reasons you point out.

They sell a kenwood unit at walmart for 60$ or less that includes bt, but in your case not for mp3 streaming.. it would be for remote control via smartphone.
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[BOOMINGRANDPA 5,000+ posts]

They sell a kenwood unit at walmart for 60$ or less that includes bt, but in your case not for mp3 streaming.. it would be for remote control via smartphone.
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my kenwood x301 is nice $119 has lots of audio adjustments and has usb and bt but idk mp3 stuff.. i run my speakers just off it and it's plenty loud even with my sub but don't know about a boat..

 

[oysterman]

Sorry, when I said remote i just meant for volume and switching between aux 1 and 2. In terms of actually controlling the music the idea is to use the mini computer on a network that my phone connects to and use an app. So there's no streaming because the mini pc is hard wired via aux to the unit,which then goes through an amp. So the unit is there purely to send the audio signal. The mini pc has Dolby and is designed for media (it's the minix u9-h that runs android). Since much of the processing of the audio signal is done via the computer, surely it's sending a pretty good analogue signal out already... hence my initial question about the need for an hu. If you strip away the need for cd, radio, BT,what else is the HU doing? If it's still doing important processing designed for car speakers (like my set up), then fair enough. In which case a stripped down unit is all I need. But with the mini pc processor and a good amp... do you see where I'm coming from?

 

[los33]

Sorry, when I said remote i just meant for volume and switching between aux 1 and 2. In terms of actually controlling the music the idea is to use the mini computer on a network that my phone connects to and use an app. So there's no streaming because the mini pc is hard wired via aux to the unit,which then goes through an amp. So the unit is there purely to send the audio signal. The mini pc has Dolby and is designed for media (it's the minix u9-h that runs android). Since much of the processing of the audio signal is done via the computer, surely it's sending a pretty good analogue signal out already... hence my initial question about the need for an hu. If you strip away the need for cd, radio, BT,what else is the HU doing? If it's still doing important processing designed for car speakers (like my set up), then fair enough. In which case a stripped down unit is all I need. But with the mini pc processor and a good amp... do you see where I'm coming from?

Problem is the beginning source is what produces the quality of the music and really gives the music the needed touch to seperate the parts where they need to be.
The dac from your mini pc would lower the quality completely, its as good as a 20$ headunit.

These more expensive headunits were made to be dedicated to producing a better source signal.

If all you need is the music to work at the cheapest possible solution then just go with your pc and a dedicated dsp to seperate the signal.

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[youdoofus]

So yeah Head unit for car audio, absolute must. No ifs ands or buts about it. Its a lot more complicated then you can ever expect when you want a properly done setup and its not possible without a good head unit and head units nowadays are FAR more advanced than whatever you had 10 years ago. UNLESS you just want unintelligible noise that has some resemblance of music then yeah go ahead with your original idea and prepare a lot of RCA to aux and RCA y splitters.

what about soundmanca's ipad setups? doesnt he go from an ipad to a dsp?

 

[oysterman]

Problem is the beginning source is what produces the quality of the music and really gives the music the needed touch to seperate the parts where they need to be.
The dac from your mini pc would lower the quality completely, its as good as a 20$ headunit.

These more expensive headunits were made to be dedicated to producing a better source signal.

If all you need is the music to work at the cheapest possible solution then just go with your pc and a dedicated dsp to seperate the signal.

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Absolutely not! Do not want the cheapest option, I'm looking for good quality, which is why I posted up my question. I'm happy to be told it's a silly idea. I know little about the subject and enjoy learning in forums like this

But I'm interested to know what processing the Alpine F300 (what I'm currently looking at) does in place of the HU. You're saying it is not a replacement for the HU, that it is far better to use the two in conjunction with each other?

 

[oysterman]

what about soundmanca's ipad setups? doesnt he go from an ipad to a dsp?

I mean I'm such a noob I had no idea a DSP existed! Surely this is exactly what I'm looking for, no?

 

[los33]

what about soundmanca's ipad setups? doesnt he go from an ipad to a dsp?

Apple produces some of the best 32 bit dacs in its products.

Absolutely not! Do not want the cheapest option, I'm looking for good quality, which is why I posted up my question. I'm happy to be told it's a silly idea. I know little about the subject and enjoy learning in forums like this [emoji4]
But I'm interested to know what processing the Alpine F300 (what I'm currently looking at) does in place of the HU. You're saying it is not a replacement for the HU, that it is far better to use the two in conjunction with each other?

The alpine f300 is just an amplifier.

It processes what a amplifier is suppose to, it receives clean signal and reproduces it with a even stronger signal so the speaker outputs louder.

The true processing comes from the headunit or dsp.

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