Some basic questions about factory system.

[jmardy]

I have base model Cooper S.
It has the standard CD player.

What is BOOST, do I have that kind of deck?
Balanced line outs, can't be? Where do they go? An amp? What amp?

Here's what I WAS planning until I did a couple of searches.

A four channel Pioneer amp in the boot.
Speaker lines intercepted from the output of the deck, sent to the amp, high quality speaker wires to new speakers (component 6.5s in the door, new 6x9s in the back)

My only concern based on what I know (or thought I knew) are:
1) remote amp turn-on with factory HU
2) speaker level input into an amp gives me the willies.

Any help or clarification appreciated.
I DID many searches and didn't find any answers.

Cheers
-John

[macncheese]

From what I've read and how I understand it. Everyone in the US has the BOOST. If you look in your owner manual holder thingamajig, you'll find a manual just for the headunit which says BOOST on it.

The amp is built into the headunit. The amp is a balanced line amp.

If your (upgrade) amp has built in high level inputs, that should trigger the remote turn on. I think?

--
Cheese

[jmardy]

Thanks Cheese.
Every amp I've ever dealt with needed a separate power on signal but there might be enough voltage on the speaker level lines to trigger it. I've never used speaker level, I'm ascared.

I'll just have to try it.

So, just to clarify, there are no balanced line outs on the factory HU, right?

[MINIsota_Cuke]

Jmardy,
Could you tell me if the factory stereo/cd has a removable face?
Since there doesn't seem to be a lot of storage space in the vehicle I will probably carry a case for my CDs in and out at work and it would be nice to just pop the stereo face in the case as well.
Thanks for your help.

[macncheese]

Homeskillet,
I believe the speaker lines are in fact balanced outputs. Check out this thread. Im not a pro by any stretch at this audio stuff tho, so dont take my word for it.


--
Cheese

[jmardy]

Quote:

Originally posted by macncheese
Homeskillet,
I believe the speaker lines are in fact balanced outputs. Check out this thread. Im not a pro by any stretch at this audio stuff tho, so dont take my word for it.


--
Cheese

Speaker lines can not be balanced, they require only a signal and ground.

More than you ever wanted to know from Balanced Audio Technology's web site

In this context, the terms "single-ended" and "balanced" describe the type of electrical interface between components: i.e. preamplifiers and power amplifiers. Single-ended interfaces use a "common" conductor (shield, ground or instrument chassis) as a signal return path. Balanced lines, on the other hand, use two dedicated conductors to provide forward and return paths for signal. The ground connection in balanced configurations is accomplished by means of a third, dedicated, ground conductor. Any two components in your system will, most likely, have a measurable voltage difference between their chassis. When a single-ended cable is connected between these two components, this voltage difference will appear along the common conductor (shield) of the interconnect. As a result, the shield will now carry the parasitic ground noise current between the two chassis. Since the shield is directly in the signal path, the voltage drop along the ground conductor will be combined with the signal that the interconnect carries. The result will be added noise and distortion introduced directly into the signal path. In a balanced system, a separate shield or ground conductor will be used to connect the two chassis together, reducing the voltage difference between them. But the voltage drop across the shield will not add to the signal, because this third conductor does not carry the signal. What flows through the balanced interconnect is a clean signal, separated from extraneous ground current and noise. Additional benefits are derived from the fact that balanced circuits are inherently symmetrical. The balanced nature of the internal circuit greatly reduces transient demand on the component power supply, further improving signal integrity and noise immunity. Balanced Audio Technology's web site

[jmardy]

Quote:

Originally posted by MINIwannahave
Jmardy,
Could you tell me if the factory stereo/cd has a removable face?
Since there doesn't seem to be a lot of storage space in the vehicle I will probably carry a case for my CDs in and out at work and it would be nice to just pop the stereo face in the case as well.
Thanks for your help.

The factory deck does not have a removable face plate.

[snoopy]

Why can't speaker lines be balanced? Have a look at the problem another way.

They might be balanced feed lines (and not speaker lines) between the preamp (boost head unit) and the Amp (h/k amp or sound Modul) and we are just putting speaker on these balanced feed lines because the drive level from the preamp is high enough to drive speakers.

You can have single ended speaker lines i.e. one with a ground on one side of the speaker. But most modern car systems use a two-wire speaker system. I.e. speaker + wire and a speaker – wire. The reason is increased power, but with these systems they tell you NEVER ground one or any of the speaker wires (due to the fact they are bridged).

So we have two wires with opposite signal on each. Sounds like a balanced system to me.

But if I have missed something please tell me as I want to add an amp to my MINI and keep the factory head unit and I was going to use the speaker wires to feed my amps.

[jmardy]

Quote:

Originally posted by snoopy
Why can't speaker lines be balanced? Have a look at the problem another way.

They might be balanced feed lines (and not speaker lines) between the preamp (boost head unit) and the Amp (h/k amp or sound Modul) and we are just putting speaker on these balanced feed lines because the drive level from the preamp is high enough to drive speakers.

You can have single ended speaker lines i.e. one with a ground on one side of the speaker. But most modern car systems use a two-wire speaker system. I.e. speaker + wire and a speaker – wire. The reason is increased power, but with these systems they tell you NEVER ground one or any of the speaker wires (due to the fact they are bridged).

So we have two wires with opposite signal on each. Sounds like a balanced system to me.

But if I have missed something please tell me as I want to add an amp to my MINI and keep the factory head unit and I was going to use the speaker wires to feed my amps.

Speaker level can not be balanced because there are no electonics in a speaker driver to deal with a balanced signal.

Balanced is only for connections between active components.
Speakers are merely electro magnets and only require positive and negative power.

This is not to say that it is necessarily wrong to use the speaker level to drive an amp, but is the 3rd best behind single ended line level and -dare I say it- balanced line level.

I have never seen a speaker driver with more than 2 connections.

[jmardy]

Does anyone have an answer to the remote amp turn-on questions.
I've looked at the pinout, does anyone know what pin 16, Accessory is?

[macncheese]

John,
I think what Snoopy is trying to say is that the way the amplifier works is the equivalent of how balanced line outs work.... So while there is no benefit to having a "balanced" high level output, there is no harm either. Again, Im just guessing but this is my logic, although it may be poor.

A speaker typically sees an signal which is an amplified low level signal. The benefit of a low level output is that it isnt "corrupted" by the poor quality head unit amplifier.

Instead of the typical means of amplification (utilizing a floating ground?), the stock head unit is utilizing some method that uses both wires to drive the speaker. I think, for speaker driving purposes, this is kind of like bridging and amplifier (they two channels are out of phase, which effectively doubles the output).

Hopefully, this means the "corruption" is for the most part cancelled out, assuming the + and the - amplifiers introduce the same noise.


but then again, maybe Im WAY off and just flooding this forum with useless gibberish.




--
Cheese

[cpeters1]

I too am interested in this. I asked the question under a different thread and no answer so lets see if we can come up with it here.

[snoopy]

Remote turn on

I am guessing that you guys have the flat pin connector on the back of your radios?

If so I think pin 16 is the Accessory wire, normally this means a voltage is present on this wire when the car ignition is turn on. (you can sit in the car and listen to your radio but not have the motor running). So if you did tap this wire the amps would turn on whenever you ignition is on, not a bad idea, but try pin 13 power ant. Don’t know really what it is their for 1 could be for a power ant but do any BMW have a power ant, or 2 it provides power to the ant as it is a active ant, eg sat ant, amp AM radio ant etc etc.

But anyway measure pin 13 and see what you get, and make sure it stays their in all modes, i.e. radio and cd. But remember not to run to many amps of any pin coming from the head unit, as they are not designed to sink or source great amounts of current.

I will get back to you on the speaker level, I think the problem lays in what you call speaker level and it's meaning to me.

[snoopy]

Speaker level: Is a level of signal that is great enough to drive a speaker coil to produce a sound. This may be a single end (i.e. one side or the speaker is connected to ground) or it may use two wires. (speaker + and Speaker -) Both systems will product a sound as current is flowing thought the coil of the speaker.

Single ended: you have one wire to carry the signal and the ground is use as a reference at the other end of the wire.

Balanced: you have two conductors that carry signal and reference to one anther at the other end. Balanced systems do not require electronics to work, and speaker can work from them. The reason being is that there is still current flowing from one conductor thought the coil of the speaker and the to the other conductor. Any noise that is induces on these conductor is in the same direction therefore the speaker does not reproduce it. (remember it reproduces the difference between the two wires)



The best feed system in the world is balanced, no question about it.

The reason balanced is far better in feeding audio systems. Is in a single ended system the reference point (or ground) is not the same level. When you get noise in a system it will show up in the ground wire. This means your reference is not the same at each end, therefore the amp does not know what is wanted signal and what is unwanted signal (the noise). The system will work if you could get both ends of the ground at the same level at the same time, but this is impossible to do.

In a balanced system each wire uses the other wire as its reference, and as the travel together (hopefully twisted together) the noise that is picked up by the wires is the same in both wires. When the signal gets to the other end it is easy for the amp to see what is wanted and want in unwanted signal.

Also running a RCA or signal end feed system would cost too much in terms of the wiring loom used. Must use shield cable for signal end feeds, but with a balanced feed you can just use cheap old wire, because you don’t care how much ***** it picks up as you amp can filter it off.


Now in the past speaker levels have been frowned on, but some of these were single end systems (i.e. you connected one side to ground) and they have poor noise immunity. Next most final stage designs are driving the amps as hard as they can to get nice big numbers. So they can put these big numbers on the front of stereo boxes. By driving hard you create distortion and crap signal.

But if you have a look at the output of the MNINI boost head unit the power output is not that high. As I have not been able to hook a head unit up to a cro to see the waveform for myself I will have to take a educated guess that the reason that they do not push the finals in the head unit to max output of about 22 w rms running at 14.4 v Is that this creates distortion and you cant’ fed your h/k amp or sound modul amp with distorted signal.

In cheap amps and cheap level connecters (high to low or speaker to line level) some of them tire one of the conductors to ground. This straightaway take the most important feature of a balanced system away, two reference wires. Therefore noise comes back into the system and as speaker wires are not normally shield wires they pick up any noise very easy.

Can I ask you guys why you don’t like good balanced speaker level inputs? What troubles have you had with them in the pass?