[DEE83]

Hi All,

Hoping to get some advice please, so after a lot of debating i decided to go ahead with the MB Quart BMW 200.3 speakers and a MB Quart Nano 475 AMP.

So this weekend I fitted the speakers " All seems to be working " and instead of running the woofers and under seat subs on separate channels.

I tapped into the original speakers wires, thus running all speakers on one channel and bridging them on the amp.

My question is by doing this, i'm i causing any damage to the amp or speaker's if all three speaker are running off one channel on a bridged amp.

Thanks for your advice

[shnaggs]

Wait what??? How many channel amp is this? If I understand you correctly, you are running all speakers-left and right, on 1 bridged channel???

Ideally you want a channel for front left, i.e. Mids and tweets with crossover and a channel for the front right side. Plus you should run seperate channels for left midbass and right midbass. You do this cause you need a different frequency range running to the mids than you do the midbass. Having the full frequency spectrum running to all speakers is just a disaster waiting to happen

[DEE83]

Hi Shnaggs,

Firstly thanks for your reply

The amp is a 4 channel but I am running each side ( three speakers ) on an individual channel, i.e left side channel 1 / right side channel 2

I bridged the amp to run it as a two channel amp as one of the channels stopped working due to an issue with the ground speaker connection and to compensate for the increase in power needed due to running three speakers on one channel.

With regards to the frequency etc, I am running both channels on a High Pass setting.

I didn’t install new wires for the under seat woofers as they are running in parallel with the door speaker so assumed it would work as before but now amplified.

The speakers have an impedance rating of 4 ohms and the amp's ratings are as follows:

OUTPUTPOWER RMS - 75 Watts x 4 @ 4 Ohms / 125 Watts x 4 @ 2 Ohms / 250 Watts x 2 @ 4 Ohm mono bridged

[shnaggs]

What are you high passed at?

Should have asked this earlier, do you have the base audio system? You are tapping into the speakers via the factory wiring?

I'm just worried that you are sending unwanted signal to either the door mids, or the underseat woofers/midbass.

The mids in the doors should really only be playing down to 150-200hz. The midbass should be taking over from there on down, so 150ish down or just low passed. If you are running both the mids and midbass on the same channel, you have no way of controlling either of those variables.

[DEE83]

HI

The high pass filter is at 150hz,

I have the base audio system, I've tapped into the factory wiring for the component speakers but left the under seat speakers running in parallel.

Would not having no way of controlling either of the variables you stated above damage the speakers.

My main concern is the amp, as I've bridged it, is this suitable and safe as the amp is getting quite hot.

The way i figure it, is I am giving 250 watts to each channel to compensate for running three speakers off one channel.

[ctuna]

http://www.e90post.com/forums/showthread.php?t=704363

The fact you are running them with the factory setup in parallel is bad enough.
There is no way to provide the right frequency
ranges to both the underseats and doors with
this setup.

[DEE83]

Originally Posted by ctuna

http://www.e90post.com/forums/showthread.php?t=704363

The fact you are running them with the factory setup in parallel is bad enough.
There is no way to provide the right frequency
ranges to both the underseats and doors with
this setup.

Hi Ctuna,

If i've read your post correctly, you are under the assumption that I still have the factory head unit ?

If that is the case, I removed that and have an aftermarket headunit fitted.

[ctuna]

This is about sound quality I read you had an amp
Its not about the the bad factory eq in OEM head unit.
You are trying to provide eq to three speakers at once
on one channel ,even though you have a passive crossover in the doors
this is not a great way to get good sound quality.

[DEE83]

It doesn't sound to bad now, but if I can get it sounding better then it looks like my weekend is going to be spent running cables from the seats to the boot.

Thanks for the feedback,

[Lockman_321]

Hi Dee,

You want to run it like this

Left door plus tweeter = 1 channel
Right door plus tweeter = 1 channel
Left underseat = 1 channel
Right underseat = 1 channel

The reason for this is the frequency ranges in which you want to send to the speakers.

As you have an amplfier (the same as me) you can manage the frequencies being sent to each channel using the crossovers on it.

The doors plus tweeter are for playing the higher end frequencies and the underseats are for playing mid (or lower) frequencies.

In my system I have a boot sub aswell as the mbquart 200.3 so i am running my subwoofer for the lower end frequencies, the underseats for mid frequencies (mid bass) and fronts for higher end frequencies. You will also notice that there is a crossover between the tweeter and the door which splits the frequencies between the door and the tweeter playing the highest through the tweeter.

By setting it up like this it allows you to have a full range of sound.

If you bridged the underseats with the doors / tweeters and they are all on the same channel on the amp, it means you are unable to seperate the sound between the door speaker and the underseat which is what you want to do.

You will notice a huge difference once you set the crossovers correctly and play different frequencies ranges on different speakers.

I hope that helps.

[DEE83]

Originally Posted by Lockman_321

Hi Dee,

You want to run it like this

Left door plus tweeter = 1 channel
Right door plus tweeter = 1 channel
Left underseat = 1 channel
Right underseat = 1 channel

The reason for this is the frequency ranges in which you want to send to the speakers.

As you have an amplfier (the same as me) you can manage the frequencies being sent to each channel using the crossovers on it.

The doors plus tweeter are for playing the higher end frequencies and the underseats are for playing mid (or lower) frequencies.

In my system I have a boot sub aswell as the mbquart 200.3 so i am running my subwoofer for the lower end frequencies, the underseats for mid frequencies (mid bass) and fronts for higher end frequencies. You will also notice that there is a crossover between the tweeter and the door which splits the frequencies between the door and the tweeter playing the highest through the tweeter.

By setting it up like this it allows you to have a full range of sound.

If you bridged the underseats with the doors / tweeters and they are all on the same channel on the amp, it means you are unable to seperate the sound between the door speaker and the underseat which is what you want to do.

You will notice a huge difference once you set the crossovers correctly and play different frequencies ranges on different speakers.

I hope that helps.

So i spent the day running cables to the under seat woofers and WOW what a difference it made running the speakers on the correct frequencies.

So slights tweaking and a few layers of silent coat and I will be one happy chappy.

Thanks all for your feedback.