Question about gain setting

[ejschultz 10+ year member]

My girlfriend's brother wants me to set his gain with my DMM for his subs. He's using some no name 2 channel amp to run 2 12 in MTX 4500s. The subs are single 4 ohm coils. The amp is rated at 800 RMS, but I'd assume it's more around 600 if that. It's got 2 30 amp fuses. If I wanted to give each sub around 200 watts, would I multiply 4 x 200 then sqrt it or 4 x 400 then sqrt it? The subs are not going to be bridged, but ran off their own channel. I'm pretty sure it's the 200 x 4 but I want to make sure. Thanks.

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[ejschultz 10+ year member]

No responses yet? I'm sure this is an easy question and someone has to know. I'm pretty sure it's the sqrt(200x4). LMK.

 

[Fique 10+ year member]

Bridge the amp to two ohms run the subs at 2 ohms. Most you are gonna see outta the amp.

 

[ejschultz 10+ year member]

Seeing the amp is some no name POS, I would assume it's not 2 ohm stable bridged. The amp should have enough power for two 4500s. They only want 225 each in a sealed box. He's got them in a prefab ported box. I don't want to do more than 200 to each sub. I don't want him to blow them because every time something gets messed upon there, he gets more junk for it and wants me to put it in.

 

[ejschultz 10+ year member]

Anyone else?

The amp is an Audiofonics ADF-2843. The only thing I can find about this amp is it's 1600 watts and 2 ohm stable. I know it means 1600 watts peak. Like I said, it's got 2 30 amp fuses so I'd assume it's doing somewhere around 600 watts rms @ 2 ohms bridged, assuming it's 2 ohm stable bridged, as it is not specified 2 ohm stable per channel or bridged. Otherwise I'd assume it's probably around 150x2 @4 ohms and 300x2 @ 2 ohms. Help me out here. The manufacturer's website sucks and doesn't give any information on power other than 1600 watts. I think I'm probably guessing pretty close to what kind of power it can really put out, but I'm not sure. After getting that info, I'd probably be giving each sub 125 to 150 watts if I don't bridge them. If I bridge it, assuming it's stable for 2 ohms bridged, I'd probably try to get about 400 rms out of it, again assuming the amp is actually capable of this.

 

[ejschultz 10+ year member]

An o-scope would be sweet at this point to actually figure out where this mofo clips...

 

[ejschultz 10+ year member]

Does anyone have any suggestions or possibly experience with this or a similar amp? I have answered my question about setting the gain, but I do not know where to begin to figure out what type of power the amp is capable of supplying. The manufacturer sucks as far as supplying specs; well, they probably **** at everything.

 

[Techchild 10+ year member]

Turn the gain/bassboost all the way up.

 

[ejschultz 10+ year member]

Turn the gain/bassboost all the way up.

I'd like to do that, however, I don't feel like buying him any new equipment. Although, I have a feeling over time, he's going to change the what I set and turn everything up and blow shit just like he always does.

 

[alvitae 10+ year member]

Here ya go. http://www.teptronics.com/adf2843.html

* ADF Series 2-Channel Class AB Car Amplifier* RMS Power Rating:

o 4 ohms: 150 watts x 2 chan.

o 2 ohms: 220 watts x 2 chan.

o Bridged, 4 ohms: 450 watts x 1 chan.

* Max power output: 800 watts x 2 chan.

* MOSFET power supply

* Wired remote bass level control included

* LED power and protection indicators

* Tuned Bass EQ (0-18 dB bass boost at 45 Hz)

* Oversized capacitor tanks

* Bridgeable operation

* Input sensitivity controls

* Speaker-level inputs with soft turn-on/off circuitry

* Preamp RCA outputs

* Thermal and short circuit protection circuitry

* Heavy duty aluminum heatsink

* Gold-plated RCA level inputs

* Gold-plated screw terminals

* Variable high-pass filter (40-400 Hz, 12 dB/octave)

* Variable low-pass filter (40-400 Hz, 12 dB/octave)

* Frequency response: 10-50000 Hz

* Dimensions: 8.7"L x 16.2"W x 2.0"H

* 4-gauge power and ground wiring is required for installation. Contact us for information regarding a discount on select amplifier kits when purchased together with this amplifier.

* Authorized Internet Dealer

* 2-year Manufacturer's warranty

 

[ejschultz 10+ year member]

Here ya go. http://www.teptronics.com/adf2843.html

Thank you. I seriously must be stupid. Every site I tried had the same shitty specs the manufacturers website offered. Those are actually pretty close to what I assumed, at least for 4 ohm loads. I wonder how accurate those are now. Do you think it'll really do 150x2 at 4 ohms?

 

[Techchild 10+ year member]

I'd like to do that, however, I don't feel like buying him any new equipment. Although, I have a feeling over time, he's going to change the what I set and turn everything up and blow shit just like he always does.

Grow a backbone if he blows it up it's his own **** fault, tell him to buy his own shit or gtfo, I would start charging for installs also. //content.invisioncic.com/y282845/emoticons/cool.gif.3bcaf8f141236c00f8044d07150e34f7.gif

 

[ngsm13 5,000+ posts]

Use your ears...

 

nG

 

[ejschultz 10+ year member]

Grow a backbone if he blows it up it's his own **** fault, tell him to buy his own shit or gtfo, I would start charging for installs also. //content.invisioncic.com/y282845/emoticons/cool.gif.3bcaf8f141236c00f8044d07150e34f7.gif

It's my girlfriend's brother. I'll do his shit for free. I'm not going to set his gain so his equipment gets destroyed. He'll do that in time or one of his dumbass friends will try and turn up his bass boost and tune it better than me and blow it like the last time. I really hate when someone ****s with my work, shitty equipment or not, it still takes time.

 

[ejschultz 10+ year member]

Use your ears... 

nG

That's normally what I do, but I'm trying to do it with a DMM now just to see if there's an audible difference. As of right now, I don't have any comparison because my DMM is taking like a month to come in. It was hard to find one that had an AC voltage range up to 1000 Hz instead of the standard 400 Hz with a decent accuracy.