wiring question

[Doug535]

Why can't I get over 13.60VAC at amp output?

Why can't I post my info, it tells me post denied limited by urls blah blah blah

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[Doug535]

Post denied. New posts are limited by number of URLs it may contain and checked if it doesn't contain forbidden words.

No urls are being added or curse words, whats up?

 

[Side Show 10+ year member]

what amp? whats the issue?

 

[Doug535]

HU-Pioneer DEH-6500BT

Door Spkr Amp-Autotek M1000.4

Sub Amp- Autotek M2500.1D

Sub- Alpine SWS-12D2 @ 1ohm

M1000 is powered by 8ga power and ground wiring. (no probs with setup)

M2500 is powered by separate 4ga power and ground wiring. (separate ground from M1000)

RCA's piggy backed from the M1000

During setup @ 45volume with 50hz @ 0db running, vehicle running and 14.09VDC at the amp the highest voltage I can get at the sub/speaker output is 13.60VAC, according to my calculations I need to hit 35.35VAC.

What am I missing or doing wrong, and yes I know this sub is a little small for the amp.

 

[Side Show 10+ year member]

very small sub for the amp, maybe re-wire the sub to 4 ohm and reset your gains, also try another rca from the headunit to the amp.... the rca output on the amp might be dicky

 

[Jepalan]

What have you tried?

What test signal are you using? 50Hz at 0dB?

What voltmeter are you using? Is it set to AC volts?

Are head unit RCAs configured for SUB outputs in the HU menu?

Are the crossover freqs set correctly in HU menu?

Is the sub output cranked up in the HU menu?

 

[Doug535]

I actually had the rca's running from the rear/sub out on the HU originally and could only get 5.90VAC, after I changed it to the piggy back I can get 13.60VAC

 

[Doug535]

What have you tried?

What test signal are you using? 50Hz at 0dB?

What voltmeter are you using? Is it set to AC volts?

Are head unit RCAs configured for SUB outputs in the HU menu?

Are the crossover freqs set correctly in HU menu?

Is the sub output cranked up in the HU menu

Most of this is answered in the above post //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

When it was hooked up to the HU it was setup correctly to sub/w out and yes I did try full bass boost in the menu. Now it is piggy backed to the M1000 amp. Still cannot achieve 35.35VAC @ the speaker output of the M2500. I cannot get the sub to distort or clip at max level and max bass boost on the amp, which should be pushing 1250w/rms into an 500w/rms sub.

 

[Jepalan]

I actually had the rca's running from the rear/sub out on the HU originally and could only get 5.90VAC, after I changed it to the piggy back I can get 13.60VAC

Must be something else really wrong. You should be able to get full output using the 2v RCA outputs from the HU. Try a different set of RCAs into the amp

 

[Doug535]

Must be something else really wrong. You should be able to get full output using the 2v RCA outputs from the HU. Try a different set of RCAs into the amp

Should have said I've tried 2 other sets of RCA's, both amps are new. M1000 purchased local (not having a problem with it) and the M2500 from Sonicelectronics (not a bash on them BTW) so I'm sure its got to be something I'm missing. Grounds are sanded and solid as are Batt + connections.

 

[Side Show 10+ year member]

check your batts voltage? i'm a bit stupped on this one

 

[fasfocus00 5,000+ posts]

IMO I don't think the sub is wired to one ohm. That 13.6 VAC is about what that amp produces at 4 ohms. I don't know how you got the 35.35 figure bc that amp isn't going to produce 1250 watts rms. at 1 ohm it'll be closer to 26-28 VAC.

 

[audiobaun 5,000+ posts]

What Vehicle is it?Are you running STOCK Alternator, and just STOCK Battery?Whats your electrical System consist of?It takes power to make power, and STOCK isnt going to get it for those amps.

 

[Jepalan]

Should have said I've tried 2 other sets of RCA's, ....

It would help tremendously if you posted *everything* you have tried already in a single post.

I agree with poster above - you are not going to get 1250 watts RMS out of this amp. It only has a single 80 amp fuse. It cannot put out more power than goes in. My guess is you will be lucky to get 600~800 watts continuous out of it.

I'll be generous:

Pin = 13.6 * 80 = 1088 W, at 80% efficiency the amp might do 870 W RMS, but I doubt it is 80% efficient.

If you are sure your power and ground is good, you may have a bad amp - seems like it should at least do 28~30VAC into 1ohm. Are you *sure* you have a 1-ohm load?

 

[Doug535]

Thanks for all the info so far, it is a 92 Volvo 740 wagon, yes stock alt and batt. I came up with the 35.35vac by 1250 x 1ohm = 1250 & sq root of 1250 = 35.35. Is this wrong? My brother in law has a hifonics Brutus with 1200rms rating and a swr-10d2 sub at 1ohm and it slams pretty good, gonna do an amp swap tonight and see if it does better in his system, may help pinpoint wether its my power or the amp. I'll report back later this evening.