Amplifier Setting Tutorial

[helotaxi 5,000+ posts]

Non volatile memory and a digital contro lcircuit should be easy and cheap enough and you would think it would be worth it for the amp company to avoid the hassle of wingnuts blowing their amps because they don't know how to set a gain.

 

[thch 10+ year member]

hmm. it would be nice for some uses, but I don't think its cheap enough. the signal processor would need a microcontroller, some type of clipping detection, and some way to control amplification. this is either ADC+DSP+DAC, or use of some digital potentiometer.

the user still needs to calibrate the unit before using it, requiring the manufacturer ship a test CD with the amp.

keep in mind that most amps tolerate clipping fairly well. By telling the user to set gains based upon this theoretical ideal, the user will get lower average SPL with music then they would if the amp was set up by ear.

MANY users would demand a way to bump up the gains to what they want, and would likely get an amp that works with the excessive gains then one that protects against it!

and some people set gains lower then this method would.

 

[helotaxi 5,000+ posts]

You're taking the idea far beyond where I was thinking and getting the control too invasive. My basic though is simple level matching. You set the volume and the amp uses a table to match the max voltage at the max volume with the required input voltage to get max power out of the amp. I'm not talking a true smart amp (though I've seen a few on the market that start to attenuate when they detect clipping) just a simple gain level setting. The engineer should know what the amp is capable of and shoud be able to design a simple circuit that matches the input voltage with the needs of the output to keep from clipping the amp and at the same time get full (or at the very least rated) power out of the amp. Test CD costs less than $.25 to make so that's not really an issue. Would be much quicker than setting up the amp with a DMM or scope, calibration would take all of about 15 sec. If you wanted o be able to overdrive the amp, simply trick it by not turning the volume all the way up on the source during the setup, if you want to turn the level of that channel down, use an outboard unit. Most all worth having have individual level controls. Set the gain then turn down the level control.

 

[stalephotograph 10+ year member]

hey guys sorry to bump this and if this has already been asked. but im going to be running a diamond d5 300.4 amp w/ a set of diamond comps and coaxs. the comps and coaxs are all 4ohms. would i add up the wattage from all the speakers and use that on the voltage calculation or just use the 300watts from the amp in the calculation? total newb on the whole components setup.

 

[BLD 25 10+ year member]

Hey, i read tons of the tutorial and gain threads, but one quick question. The threads say to turn off all bass boost, etc at the head unit. I have a pioneer 6800, and i set the bass flat, and turned it to the mid 30's for volume. My question is regarding the "loudness" feature. I always have this on, so if i turned it off to set the gains, i would blowout the speakers. So i left it on, and set the gains with the DMM, and turned everything back on, and it seemed really quiet. I had to turn the bass to plus 4 with 657 watts. Any advice? It sounds cleaner, i just wanted to make sure i did it right.

 

[BLD 25 10+ year member]

anyone?

 

[helotaxi 5,000+ posts]

It sounds like you might have used a 0dB sine wave to set the gain. Try a -3 or -6dB tone and reset it without the loudness. I know that some loudness circuits are volume dependant. As you turn up the volume, the loudness circuit turns itself down/off.

 

[luvinthebass 5,000+ posts]

my pioneers loudness turns itself off after volume 20

 

[BLD 25 10+ year member]

I don't think mine does that. I tried it on my 7600mp (other car), and it gets super quiet with the loudness off. So with the gain adjusted with the loudness, the bass is quiet. With the gain adjusted with loudness off, when i turn it back on it is overpowering and near clipping.

 

[BLD 25 10+ year member]

bump

 

[dleccord 5,000+ posts]

loudness being off is a must. but i dont believe in keeping the EQ flat or bass to 0.

volume has to be up there. i set mines around 28/35 to be safe.

when i set the gains, my volume is high, and EQed. so if you have it flat, you might not like it or get the results you're looking for.

 

[helotaxi 5,000+ posts]

If you always have the loudness on, and it doesn't self defeat at high volume, you need to account for it when you set the gains. Same with any bass or treble controls or EQing. You need to find the center freq of the loudness boost and use that freq as your test tone when setting the gain also.

 

[BLD 25 10+ year member]

hmmm....how do i find that out. Sorry, not trying to sound dumb, but i have read page after page on how to do this, and no one mentions loudness.

 

[luvinthebass 5,000+ posts]

like if ya set the gain without the loudness with a 0 db tone or a -3 db tone or a -6 db tone since most music won't reach -3 db and you engage the loudness it will be louder and will be clipped maybe, i say screw the loudness and set your head unit at 3/4 of full volume and your done.

the center frequency is usually 40 hz, that's what i use for my pioneer when i had subs

 

[type[s5] 10+ year member]

wow this didn't get stickied yet?