Amplifier Settings

[halla26]

Hi
currently got a
Fusion 12" Sub 400 watts with encounter amp powering it
225 watts JBL 505CE powered by a QXT275 400w amp
Alpine X300 headunit currently handling clio front stock speakers

Wondering how the hell to set these up on the amps, such as HPF/LPF/Hz etc, it bamboozles me.
Tried looking around finding out about how low pass filters and high work, but not sure on what should have for what.
Any help be seriously great.
Thanks

 

[Dan R]

Cross over on sub set to low pass filter and about 80 hz will be fine

 

[halla26]

Cheers, little stuff like that Im not sure on :$
Gain I set to the same voltage as headunit?

 

[Dan R]

Cheers, little stuff like that Im not sure on :$
Gain I set to the same voltage as headunit?

Gain is what ever you want really. Not flat out but u need to work it out according to how much the front speakers will take before going into distortion. U can only set that by playing around with it.

 

[AlexG]

Speakers set to hpf
Sub set to lpf
Set the crossovers to however sound good.
Gains need to be set with test tones. Type in realm of excursion on google and find test tracks for 1khz and 40hz. put them on ur ipod or a cd then go to the car. put all gains to 0 and the headunit settings all back to 0 play the track and put the headunit volume to about 90% of max. or a resonable number like 32/35. Increase the gain until the tone changes. knock back the gains slightly just before the tone changes.
repeat for the sub at 40hz.

 

[halla26]

Perfect that cheers, time to find a empty car park and give it a whirl

 

[Skinny]

Gain is what ever you want really. Not flat out but u need to work it out according to how much the front speakers will take before going into distortion. U can only set that by playing around with it.

lol.


Yes chap, the gain needs to be set at the same voltage as the HU, this can be checked by a MM or you can also use a oscilloscope to check. But if you know what it is, might be in instructions, you can set it this way, just be careful with the gain. You may think, turining it up is like a volume control, but the gain is f**k all like a volume control.

And as said, set them up by ear, unplug the sub and do the speakers, and then unplug the speakers and do the sub, try some different genres of music, and set it up and a medium - loud volume.


Don't crank your head unit up all the way, to about 2/3 or 3/4 as over this it will start to clip and cause didstortion, you should be able to tell when it distorts and at this point just turn it done one or two notches.

 

[wallop]

A few pointers copied & pasted from previous thread, (not linking to full thread as its a little too much)....

basic settings to start with;

head unit;
bass---at "0"
treble---at"0"
any factory preset eq's---off
any added bass circuits---off
graphic or parametric eq's---flatline at"0"
any media expansion circuits---off,(these are used to improve mp3 playback quality).
bass boost features---off
In the case of 'ALPINE head units' the sub output level should be set at level 15 out of 15, on ALL other brands, sub output level should be at '0'....

Mids/Tweeter amplifier QXT 275;

crossover switch---set to high pass
gain control---set to min
freq control---set to approx 100hz
stereo/mono switch, (if present)---set to stereo
bass boost circuitry---set to min or off

Sub amplifier ENCOUNTER;

crossover switch---set to low pass
gain control---set to min
freq control---set to approx 80hz
stereo/mono switch,(if present)---set to mono
bass boost circuitry---set to min or off

Test tone downloads

Now your ready to begin;
To avoid problems associated with your headunit running out of power and supplying a clipped signal you should select as your max volume a point approx 20% below max, so if using a scale that goes from 0 up to 35,(like alpine's), you should treat say 30 as your max "safe" volume.

So, go somewhere where your not going to offend people, select your head units safe volume and play a 1khz test tone,(you can download it from link previously supplied), on repeat.
On your QXT275 amp settings adjust the gain control upwards until the test tone changes, this change is where your amp is clipping, now back off the gain slightly so the tone is playing as normal again, thats the gain approximately set....

Now play a 50hz test tone, (again downloaded from previous link), and adjust the ENCOUNTER amps gain in the same manner, as you hear distortion back off slightly, thats the sub amps gain approximately set.

Now play a dynamic cd that you are familiar with to adjust the crossover freq's to your taste. You should adjust both crossover points downward, (as a novice you may well be happy as it stands).....

When complete you should have a basic setting that you can tweak to get it as you want it, this won't take 10min's, it will probably take day's.

To balance the bass to your front end, (in your case rear end), you should always alter the highest one, so if your fronts/rears drown out your sub, then lower the gain on the fronts/rears, if the sub drowns out the fronts/rears, then lower the subs gain control.

You should bear in mind that you have set the gains using a source recorded at 0db, so if you will only be playing music, you could in theory increase the gains slightly to give a higher overall output.

Hope this helps a little....wallop..

 

[halla26]

I have just declared my love for wallop
Cheers

 

[Djw John]

Good post wallop, nice lack of techno babble