Takechan

Hi,

I got a BMW E60 525d from 2007 (LCI) - unfortunately the sound system isn't very good. I've got the most basic "Base Stereo" with all the speakers powered by the HU. According to the link my speaker level input is highly equalized - is this true?

A few months ago I installed the following:

• Front speakers: Rainbow DL-C4.2
• Subwoofer: SWS 8X
• Blaupunkt THA-555 PnP

I wasn't really satisfied so I've ordered the following:

• Amplifier: JL Audio XD700/5
• DSP: Audison bit Ten

However; I'm not really sure how to adjust the input sensitivity on the Audison bit Ten seeing as I have no idea how to reach 75% of max volume on my car. The volume knob doesn't have a fixed range and the iDrive does not show how high the volume is...

1) Does anyone know how far the dails on the bit Ten should be set?
2) With low level input from the Audison (max 4V) should I set the input dials on the JL Audio to max (4V)?

I hope my questions make sense

Best regards,

Peter

twh

Here is a strategy for determining the 75% point of high volume. I would do this with the car not running. Turn the radio or CD on and the turn the volume knob clockwise several complete turns. This will be very very loud. The idea here is to ensure you have turned it all the way up no matter how high that is. Now, slowly turn the knob counterclockwise counting the number of clicks you feel as you turn the knob counterclockwise. Stop turning the knob when you can't hear any sound. The 75% mark is 0.75 times the number of clicks you counted in the clockwise direction.

Takechan

Hey twh, great idea thank.

I think I might do that, but I'd have to install an old speaker instead so I don't damage the new ones

Some guys on another M3 forum did the same, but I'm not sure if the clicks are the same on mine.

Why hasn't anyone done this with a stock head unit yet ?

Takechan

Ok found a good method.

Used the Audison test CD track #5 with 1KHz 2 min. sound (0db)

1) Disconnected all cables
2) Turned volume to max (several clockwise turns)
3) Turned back volume knob back 20 clicks
4) Reconnected cables
5) Turned back volume until audio dissapeared

Result = 47 clicks

It was consistent since I did it 3 times to be sure.

So I'm hoping that it translates into:

80% = 47 * 0,80 = 37.60 clicks (approx. 38 clicks)
75% = 47 * 0,75 = 35.25 clicks (approx. 35 clicks)

So... Audison recommends 80% so I guess I'll stick to around 36 clicks from 0

twh

Let us know how the new setup sounds when you get it all in

methodsound

Peter,

I think that you are going to need all the signal running into the Audison that you can get, even if it has some distortion on it. Try your 36 click but don't be afraid to go 42 or 45 and try it. You might end up with a better signal to noise ratio that way, less audible background hiss. See if that makes a difference.

In the previous system, which you were not satisfied with, had a five channel amplifier. For your new setup I would suggest running the front underseat woofers in stereo not mono. A 6 channel system with true left and right woofers. That would help in the lower midrange/mibass region where the 4s in the doors are going to really struggle. Consider that with a 5 channel amplifier you will have mono sub ( which is ok ) but also you will have mono midbass.

Takechan

twh, I will, thanks for the tip btw.

methodsound, thanks for the input. I'll give it a try once I've install the new components. About the subs, unfortunately my new JL XD700/5 is only 5 channel - so the sub will only be mono :/

Perhaps I should have opted for another amp.

Takechan

Failed!

Somehow I must have blown my CCC. I hooked everything up today and lights blue on the Audison an green on the JL Audio amp (no RCA plugged in). I started doing the input sensitivity adjustment on the audison and turned up the volume on the radio to 80% (as described above). The clipping lights came up for front, but not rear. I disconnected everything and connected the stock wires - no sound at first now popping sound (even with the car off...).

What to do? It must be a broken CCC, since I reconnected the old wiring and remolved all the non-OEM stuff just to check.

I got sound in the right side of the car, but popping noise in all the speakers :'(

Where do I buy a replacement CCC? I don't know which part no. is the right one:

twh

I don't fully understand your setup, but I'm assuming you are using the line level outputs of the CCC to drive an amp with line level inputs. What input impedance is the line input amp set to show the CCC? Do you know what the stock speakers are expecting (e.g. 2 ohm, 4 ohm, 8 ohm)? Most amps would have overload protection, not sure about CCC. Are you sure the speakers are blown?

Takechan

Hi,

This was my setup:

1: Head unit
2: DSP
3: Amp

1. OEM CCC (speaker level) -> 2. Audison Bit Ten (RCA output) -> 3. JL Audio (RCA Input)

I think the OEM CCC is blown, not the speakers... When I was adjusting the Audison and turned up the volume to 80% at some point all the clip LEDs started blinking and it turned off. At that point the HU must have broken. Afterwards I disconnected the Audison and tried to run the HU directly to the speakers and the popping started. I get pops as soon as I connected the HU - even when it's turned off.

I've ordered a replacement, but since I'm not sure what root cause is I'm hoping the same won't happen twice (fingers crossed).