22 replies to this topic

[birdd]

I'm in the process of building my carputer for my new car (I had an older install in my old car, but I've updated the hardware and software for my new car).

I'd like to be able to completely replace my headunit in my car.

The headunit functions I need to replace are: Built-in Amp for speakers, Radio, Volume Control

Now I have a amp for my sub which I'm already running and a spare 4 channel amp which I can use to run my front and rear speakers, so thats the amp side of the headunit taken care of. I'm thinking of getting one of those Audigy 2 NX USB External Sound cards for better SQ.

The radio, I guess I can add one of those HQTi (or whatever they are called) and that will give me AM and FM, so that's that solved...

Now the last one is the Volume Control. I've been wondering how the best way will be to replace the volume control? I know I can control the volume on the carputer with the touchscreen but to do that quickly or without looking is a lot harder. So I was wondering what the option are? Two options I've thought of are, getting one of those 1/2 DIN pre-amps and use it for volume control, the second option I have thought of is to make a hardware interface (maybe using one of those free spinning electric components that are used in HiFi volume controls (can't think of the name) and connect it to the serial port and have some software to control the volume in windows. But the issue with that is if Windows crashes I won't have control over the volume and also that won't work for POST/BIOS volume etc...

Any ideas? or suggestions for any of the items?

[Pulse-R]

Griffin Powermate

[birdd]

Pulse-R, on Oct 7 2009, 06:44 PM, said:

Griffin Powermate

Hmm I think they are bit too big for what I want... I want to keep the factory style look... I don't want a huge volume knob...

Also I'm thinking hardware volume control is probably the best way to go so that i can quickly control the volume if the computer goes weird... also so that i can control the volume of the startup sounds as well... and not reliant on booting into windows to control the volume...

[Big_Valven]

a potentiometer connected to a 3.5mm plug on one end and RCA plugs on the other end will do exactly what you want.

[birdd]

Big_Valven, on Oct 8 2009, 03:04 PM, said:

a potentiometer connected to a 3.5mm plug on one end and RCA plugs on the other end will do exactly what you want.

Yeah ok but how would that go for SQ?

[birdd]

Is there anything wrong with going for a 1/2 DIN preamp? I see that's what they use when they put Carputers in the cars on Pimp My Ride...

[Pulse-R]

AudioControl MVC (if you can find one ) has a small knob. 6x in, 6x out volume control

[birdd]

Pulse-R, on Oct 10 2009, 04:08 PM, said:

AudioControl MVC (if you can find one ) has a small knob. 6x in, 6x out volume control

Does it have a master volume control over all channels?

[birdd]

This is the sort of thing I was thinking of: http://cgi.ebay.com.au/Lanzar-VIBE750S-Hal...p3286.m63.l1177

But I'm not sure how I'd go about setting that up? Do i just run 2 channels from the carpc to the pre-amp and then the preamp splits up the channels for front and rear and sub (obviously hooked to the amps first before the speakers)

[Big_Valven]

birdd, on Oct 8 2009, 05:13 PM, said:

Yeah ok but how would that go for SQ?

It's better than anything else at all!

1 moving part
1 circuit component
No power supply to introduce interference
no A/D and D/A conversions
no chance of ground loops
no raising of noise floor or S/N ratio
absolutely NO active circuitry to introduce distortion or interference at all!

Have a look at Matt VIP's build thread, I made a 4 channel passive attenuator for his SQ setup, just 4 potentiometers, some shunt resistors (to suit his intended use) and the associated hardware.

Why do it the hard way when the easy way is better all round?

[birdd]

Big_Valven, on Oct 15 2009, 05:43 PM, said:

It's better than anything else at all!

1 moving part
1 circuit component
No power supply to introduce interference
no A/D and D/A conversions
no chance of ground loops
no raising of noise floor or S/N ratio
absolutely NO active circuitry to introduce distortion or interference at all!

Have a look at Matt VIP's build thread, I made a 4 channel passive attenuator for his SQ setup, just 4 potentiometers, some shunt resistors (to suit his intended use) and the associated hardware.

Why do it the hard way when the easy way is better all round?

I'm now tossing up whether it is worth replacing the headunit completely or whether i should just use the Aux-in and then I also have the option of playing CDs or Radio (or even iPod with my pioneer iPod adaptor) if the carputer plays up... which is probably likely being that its Windows

Maybe I should just get a better headunit... maybe one with Optical-in? ;-) any Pioneer HUs that do that? (only because I already have the Pioneer iPod adaptor)

[artuc]

Big_Valven, on Oct 15 2009, 03:43 PM, said:

It's better than anything else at all!

1 moving part
1 circuit component
No power supply to introduce interference
no A/D and D/A conversions
no chance of ground loops
no raising of noise floor or S/N ratio
absolutely NO active circuitry to introduce distortion or interference at all!

Have a look at Matt VIP's build thread, I made a 4 channel passive attenuator for his SQ setup, just 4 potentiometers, some shunt resistors (to suit his intended use) and the associated hardware.

Why do it the hard way when the easy way is better all round?

Except for the fact that potentiometers wear and can develop scratchiness plus you have to extend the signal runs out to the potentiometers.

I've had to alter or throw out quite a bit of gear (headphones and cheap speakers) because of pot failure, typically it will first get scratchy and then when it wears even more whole channels can drop out or jump from low to high volume and so on.

Not a big fan to be honest.

I think one of the nicest ways with a carputer would be to use a digital volume control like a PGA2311 from TI, you can interface that with a microcontroller so that allows all sorts of possibilities, you can control multiple channels at the same time or independently. It would be a lot of work but I think one of those hooked up to a microntroller with a USB interface to the carputer and a rotary encoder if desired for manual adjustment would be the very best way to go. Distortion and crosstalk specs are so low that you wouldn't hear them. Just would be nice if someone manufactured that sort of thing.

I do agree though that pots are the easiest way, if they are used though I really would suggest using decent brands as a minimum. Alps are what I like to use.

[Big_Valven]

artuc, on Oct 16 2009, 12:34 PM, said:

Except for the fact that potentiometers wear and can develop scratchiness plus you have to extend the signal runs out to the potentiometers.

I've had to alter or throw out quite a bit of gear (headphones and cheap speakers) because of pot failure, typically it will first get scratchy and then when it wears even more whole channels can drop out or jump from low to high volume and so on.

Not a big fan to be honest.

I do agree though that pots are the easiest way, if they are used though I really would suggest using decent brands as a minimum. Alps are what I like to use.

Your points are valid, but of course it all depends on what you use and how you use it. A good brand pot is a must, as is a sealed, preferably larger diameter body (more contact area.)
I've had problems with pots in the same way as you but that is generally on 10+ year old equipment that's been sitting in a dusty, 40 degree shed.

Let's not forget that live sound gear still uses analogue pots in the millions (literally,) a typical 24ch desk could have up to 500 potentiometers on it and I never had a failure during my work in live sound, we had a crackly one - on an 16 year old console.

As for extending the singal runs... well you have to do that with any other option anyway... and if it's dash mounted it ain't exactly a long run...

Sounds like he might be looking to a different option anyway but I thought I'd throw the information in regardless.

[Captn_Awesome]

birdd, on Oct 10 2009, 05:48 PM, said:

Does it have a master volume control over all channels?

MVC = Master Volume Control. It was made by audio control. No longer available as far as i am aware. Might be some available NOS somewhere. Might have to look OS though.

Big_Valven, on Oct 17 2009, 10:59 AM, said:

Let's not forget that live sound gear still uses analogue pots in the millions (literally,) a typical 24ch desk could have up to 500 potentiometers on it and I never had a failure during my work in live sound, we had a crackly one - on an 16 year old console.

Unless its digital
Although having said that Id never really done the sums before and I read your claim about 500 pots on a 24 channel desk and went "yeah right, I've worked on 48 channel desks that wouldnt have nearly 500 pots" so i started doing the sums. Hell even on a small 24 channel desk 500 pots came up pretty easily and thats with a limit control over the channel! No wonder digital desks are becoming so common (yuk I hate working digital desks!)

[birdd]

Ok... I'm nearly ready for the carputer to go in the car... and now that Centrafuse has been updated with the latest Aussie Maps I've got renewed energy again...

Now I've decided I want to remove my headunit completely... I was going to mount it down in front of my gear stick, but there really isn't enough depth, and it would be too hard to make a custom mount that looks factory... so I think I'm better off completely replacing my headunit...

So I'll have a 4 channel 4x100W Response Amp (at least for the time being until I can afford to get a better amp) for the front and rear speakers, and then the 820W Response Monoblock for my sub, so I'll need 5 channels, and my current motherboard only has 2 channel out, so I could use splitters to split it into all the channels but that would give no tuneability... so I'm wanting to get a decent 5.1 sound card (probably USB2) that can run direct into the amps... Maybe via a preamp? so that I can have hardware volume control... options??

I'm thinking I may add a HQTi at a later stage if I miss having radio... but I rarely use radio anyway atm so I'll wait and see for that one...

So I need recommendations for a soundcard and maybe a preamp...