Gain Matching

[BanginGMC 23]

Gain matching two sub amps... as easy as eyeballing it, right?

If not.. details?

[jcarter1885 995]

Have you thought about running one master and the other slave so all you have to do is just set one amp and it will control both, strap the amps together.

I wouldnt say it is easy to eyeball since the settings on the amp may not be in the same place to where put the knobs but someone with more experience can chime in.

[Kanaworm$ 292]

Yes it can be done, but I would try to match the two if not "Strapped" by using an OScope.

[BanginGMC 23]

I don't wan't to strap them, because if one fails the other one will fail and that's an expensive fuck up.

I'm pretty positive i can math them together good, I was just making sure it was that simple.

[Kanaworm$ 292]

What amps?

[BanginGMC 23]

SAZ-3500Ds

[Kanaworm$ 292]

1 amp on 1 dvc subwoofer?

[BanginGMC 23]

(2) 15" AA SMDs ~ (2) SAZ-3500D

One amp powering one woofer.

[Kanaworm$ 292]

See if you can find someone to set the gains with an Oscope. I would strap if it were me.

[BanginGMC 23]

I got this

Thanks for the replies.

[CrazyKenKid 64]

hey man i have been strapping sundown amps for awhile now and let me tell you! it is good and i have NEVER had an issue!

hell i strapped 2-sae1000, 2-saz2000, and 2-2500

and for the 2500 i screwed up and had the gain well about 60% higher then it should have been and guess what they are still working (knock on wood) i have since turned them down to where they should be and wow just wow! they are great!

strapping all the way! it is easy and you only have to set one amp and let it rock and roll!

[johnecon2001 82]

You can't just eyeball the knobs and hope the amps are outputting the same power.

Sorry, that will never work. You need an O Scope.

[BanginGMC 23]

hey man i have been strapping sundown amps for awhile now and let me tell you! it is good and i have NEVER had an issue!

hell i strapped 2-sae1000, 2-saz2000, and 2-2500

and for the 2500 i screwed up and had the gain well about 60% higher then it should have been and guess what they are still working (knock on wood) i have since turned them down to where they should be and wow just wow! they are great!

strapping all the way! it is easy and you only have to set one amp and let it rock and roll!

Considering what you and John said, i'll strap them. I'm just going to hang myself with 0 gauge wire if they fail.

How'd you find out that your gain was up 60% higher then it should be?

John, thanks for clearing it up for me!

[altoncustomtech 773]

^^^^

I agree, I think strapping the amps would be the best way to go. I don't think one would destroy the other unless it was a VERY serious failure, but if you just can't drive yourself to do it then, yes an Oscope would be the next BEST. You could get by using a test tone and a good DMM though since even with the oscope all you're doing is matching the output voltage's of each amp. Regardless, I don't think strapping the amps would ever cause a problem.

[///M5 2,833]

As you already determined, DO NOT EYEBALL, but use a scope if you have to make them match. I would also strap, but still use a scope and make sure your supply voltage is strong enough to support those amps!

[antonmiller 8]

multimeter with a mid volume frequency on repeat is the way i gain match, also it is the way i ahve been setting subsonic filters and setting LPF. works great! i have a scope, but i find it hard to get everything putting out the same output (one amp may clip at a different output then another).

[johnecon2001 82]

multimeter with a mid volume frequency on repeat is the way i gain match, also it is the way i ahve been setting subsonic filters and setting LPF. works great! i have a scope, but i find it hard to get everything putting out the same output (one amp may clip at a different output then another).

So why would you use a DMM instead knowing that each amp clips at different levels? Ignoring issues is a surefire way to blow things up.

[BanginGMC 23]

As you already determined, DO NOT EYEBALL, but use a scope if you have to make them match. I would also strap, but still use a scope and make sure your supply voltage is strong enough to support those amps!

I have (4) XS Power D3100 as secondary batts (getting another one as well) and a 320 amp DC Alt ~ nearly 200amps at idle.

[///M5 2,833]

As you already determined, DO NOT EYEBALL, but use a scope if you have to make them match. I would also strap, but still use a scope and make sure your supply voltage is strong enough to support those amps!

I have (4) XS Power D3100 as secondary batts (getting another one as well) and a 320 amp DC Alt ~ nearly 200amps at idle.

Should be fine, but I'd still measure that way you KNOW you are okay

[antonmiller 8]

multimeter with a mid volume frequency on repeat is the way i gain match, also it is the way i ahve been setting subsonic filters and setting LPF. works great! i have a scope, but i find it hard to get everything putting out the same output (one amp may clip at a different output then another).

So why would you use a DMM instead knowing that each amp clips at different levels? Ignoring issues is a surefire way to blow things up.

ummm, first you use the oscope to find clipping, then you gain match with dmm... every amp is different, if you set both amps to clipping the subs will be getting different amounts of power, thus creating cancelation... there is no perfect way to do this other than strapping. ive never blown a sub in my life, id like to think i know what im doing.... lol

all i know is by using my method a buddy of mine gained close to a db by gain matching his 3 amps...

[Impious 1,476]

multimeter with a mid volume frequency on repeat is the way i gain match, also it is the way i ahve been setting subsonic filters and setting LPF. works great! i have a scope, but i find it hard to get everything putting out the same output (one amp may clip at a different output then another).

So why would you use a DMM instead knowing that each amp clips at different levels? Ignoring issues is a surefire way to blow things up.

A minor variation in clipping levels isn't going to be enough to matter. If there is a dramatic difference in clipping points, then there are some QC issues that need worked out in the amplifiers.

Oscope isn't necessarily a clipping-avoider anyways. Sure, with a 0db test tone clipping will be avoided. But the anemic average power output resulting from using a 0db test tone to set the gain isn't going to satisfy a lot of people and not optimize the use of power from the amplifier. That's why there are so many complaints about a loss of output when someone follows the DMM gain setting tutorials. A less conservative gain setting is going to allow a higher average power output but with some minor clipping of the transient peaks. A small amount of clipping at the transient peaks isn't going to damage anything unless you are already way overpowering the drivers.

My advice would be to just set one of the amps by ear, then measure the voltage and set the other to match. Anybody with properly functioning ears and a little experience should be capable of satisfactorily setting a gain by ear. The DMM/Oscope method is a good recommendation to help someone completely lost find a decent starting point. Beyond that about the only time I'd worry about a DMM is to level match multiple amplifiers.