Balance and Fader

[sharma]

Hi,

I have the becker pre out lead connected to my Symphony HU. It has 2 pre outs. I have two 2 channel amps (one pre out for each). One amp is running the sub, the other is running the speakers. Now when i use the fader i can cut down the sub or the speakers as i wish. However when i change the balance it also effects the sub. (If i change the balance fully to the left, the sub level also goes down a fair amount). Should this be happening? Is there any way to stop this happening? I can't figure out how the balance level effects the sub.

Thanks.

 

[AndyMac]

You need to switch you amp to ch1+ch2.
a lot of amps have 3 settings, stereo, ch1+ch2 and mono.
Yours is probably set to mono, which means it's only taking the left or right pre-out signal, so will go up & down with the balance control.

 

[sharma]

I will have a look at both amps. Does it make a difference to the sound quality and bass the sub produces? And what does stereo mode do? If my amp running the speakers has these settings whats it best to set that one to?

 

[AndyMac]

Err Stereo means stereo i.e. 2 different signals going to each channel.
Stereo - use unbridged driving 2 seperate speakers
ch1+ch2 - use for single sub
Mono - use for driving 2 subs with 2 amps each fed by left or right pre-out

No it doesn't affect the quality.

 

[sharma]

I cannot seem to find any settings (mono, stereo or ch1 + ch2) on either of my amps. Not sure if this is because they are 2 channel. Anything else i can do??

 

[AndyMac]

Buy a decent amp?
Re-reading your post, you say you have 2 x 2ch amps, one pre-out for each. I assume you mean one pair of pre-outs for each i.e. left & right front for the amp running the speakers, and left & right rear both going into the sub amp?
You can't feed just a left pre-out to one amp and the right pre-out to the other. If you only have one pair then you need to buy a couple of "Y" splitters and feed both pairs to both amps.

 

[dualmono21]

what amplifiers do you have ???
if you have two differnat models please give both

on some becker head units it is possible to change all or some of your pre outs to
"NON FADING" you will have to check your own manual to see if this is possible if you do this the output will be unaffected by either balance or fade

this then simply requires that the amplifier be configured correctly on its outputs

channels 1+2 in stereo mode is for front speakers
channels 1+2 together in bridged mode is for the subwoofer gives summed mono (which basically means the left and right stereo signal cancell each other out to leave only a mono signal)

 

[AndyMac]

He hasn't got a Becker HU, just standard Symphony with Blaupunkt pre-out adapter

 

[dualmono21]

sorry andy i only skimmed the post and saw becker
same applies for amp though

 

[AndyMac]

Yes we already covered that one

 

[sharma]

Hi,

Yes sorry i did mean 2 say 2 pairs of pre outs for each. I guess my amp is just not good enough. They are not big names. 1 is XS and the other Terminator.

What should the gain and Hz settings be on these amps? They are both 400 watt amps. One runs a 600 watt sub and the other runs the components. (These are not the RMS figures). I have set the amp running the speakers to high pass (no hz setting on this amp with gain half way up) and the amp running the sub to low pass (approx 80 hz with gain 3/4 of the way up).

The problem is the bass is not enough. (The sub can handle a lot more bass) and unless i crank the system up to full, the bass is not as much as i want, and the treble is too much). When i changed the amp setting to FULL for the sub the bass increases vastly. I know you are not supposed to do this but does it really do any damage to the sub?? The other option i have is to stick to low pass filter but to change the setting to well over 80 hz(120 hz). Would this be a better option?? Otherwise i will just turn the gain down on the speakers. Any advice would be great.

Thanks.

 

[dualmono21]

the amps are ok but it is possible to get better if you wish to spend more money

the gain control on an amplifier is not for volume control it is for level matching with the source unit
since the aftermarket manufacturers have no standardisation (home audio has a standard of 2.2 volts )as to what the actual pre out voltage should be the amplifier manufacturers design there units to work with a wide range of input voltages
they usually range from around 0.2 of a volt to around 4 volts but some like the xtants im using will go as high as 17
the proper way to do things is with an oscilloscope and a 1 khz test tone but it is quite technical
the gain control on a amplifier should not be used as a volume control as you can quite easilly damage system components

your high pass settings for the front components are about right but you may want to turn the gain down slightly on the amp and perhaps turn the subwoofer amp gain up slightly
you could of course turn the low pass upto 120hz and this will give you more bass but the adverse affect will be that you will be able to tell quite easilly where that bass is coming from and it may overemphasise certain bits of the music
also remember to try reversing the polarity on your subsoofer by changing the positive and negative on your speaker outputs you may find a differance there
but its your system and you should listen to it however you wish

 

[AndyMac]

400 watts peak is no way near enough to run a 600w sub.
400 watts peak is about 150wrms. RMS is the only rating you should look for. Any others don't mean a thing.
You can buy an Alpine V12 MRV-T505 on ebay for around £60, this is rated at 300wrms, but actually kicks out at least 30% more.
120Hz on a sub will sound dreadful, buy a decent amp.