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4- channel amp

drummer3462

New CEG'er
Joined
May 3, 2006
Messages
9
I have a very simple question. I have 4- polk db570's in my doors which are rated at 60 watts rms a piece. The amp I am looking at to power then has a rating of 75 rms x 4 x 4. To avoid blowing my speakers is it just as easy as putting the total volume of the amp at a max of 80% to avoid all dangers? thanks.. the amp is an Autotek ss75.4
 
Yea you should turn the amp setting up and let the amp do the work. Never turn the headunit volume up to high. 80% might be fine but at the same time it maybe to much. When you turn it up listen for any thumps, rattles, and/or distortion. If you do turn it do a tad but if not you should be fine
 
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The gain control on the amp is not a volume control. Do not turn it up to 80% unless you have super weak output voltage on your deck's output. The gain control is meant to match the voltage out from the deck to the input on the amp.

What is your output voltage on your deck?
What is the sensitivity range on your amp input?

If the deck output is close to the maximum input on the amp, keep the gain turned most of the way down so you don't over drive the input circuits on the amp and clip the signal.

If the deck output is close to the minimum input on the amp, keep the gain turned most of the way up so you can get the most out of the amp from the smallish input.

A 75 watt x 4 amp (rms @ 4 ohms) will be fine on speakers rated to handle 60 watts rms. The only time you would need to be worried is if you play the system at max volume for a while then there is a very slight risk to the speakers. 99.9% of the time you'll be fine.
 
Usually when setting gain I put the deck at about mid volume and adjust the amp accordingly, that way you still have +/- volume at the deck to work with. Your also not stressing the amp out by having the gain cranked up...
 
Just remember that when companies rate speakers they are putting the ENTIRE range of frequencies through the speakers. EVERYTHING from the LOWEST BASS to the HIGHEST HIGHS! If you really want an insurance you could always place bass blockers (see below) in your system. I have placed 125 wRMS through speakers that could only handle 70wRMS and they sounded great. I placed a slight overlap in frequencies in my sub and the sub took care of the rest of the lower frequencies.

Bass blockers are basically a passive crossover that requires no power. very simple in install.

(back of stereo------<bass blocker>------ pos side of speaker)

http://www.hifisoundconnection.com/Shop/Control/Product/fp/vpid/1563296/vpcsid/0/SFV/30046

don't let the name fool you ... they cut off frequencies below 150 hz
 
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Ya good rule of thumb I do, is set have the VOL on the deck a lil higher, and the amp set at a LOWER gain.....so if I need more juice or volume, Ill turn the deck up...not the AMPY...

Not max the amp....to lower the deck....you kinda hear me on that ya know......

So, I start with a lower AMP GAIN, and Increase the DECK to satisfy, not the GAIN on AMP....but granted you WILL have to stop turning it up at some point....but usually you can "feel" out that max level (before it sounds unfamiliar in a way) .....to quit adjusting the AMP ya know?
 
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once your amps are set correctly, you should never have to touch your main amp. My sub amp, however, has a +18 db knob (thank you phoenix gold) that I can adjust to get extrax bass out when I want. But the rest of the amps stay at the level I put them in.
 
I wish I had the alpine in dash with some alpine V-12 amps... They have the amp link which allows your to monitor and control up to 8 amps through 1 head unit... :)

Basically you take this...
x500KCE511M-f_dg.jpeg


and daisy chain with this...

kwe-061m.jpg
 
Well if you like to fine tune and monitor your amps you would.... Be a lot easier working on them from the HU then back in the trunk, plus if you had them in custom enclosures that were hard to get at the amps.... then you'd probably be glad to have some sort of remote adjustment...

As for the bass blockers, you don't need them... your amp should have a HPF (High Pass Filter) setting which will cut all frequencies below the selected Hz.... Should be adjustable...
 
Well if you like to fine tune and monitor your amps you would.... Be a lot easier working on them from the HU then back in the trunk, plus if you had them in custom enclosures that were hard to get at the amps.... then you'd probably be glad to have some sort of remote adjustment...

As for the bass blockers, you don't need them... your amp should have a HPF (High Pass Filter) setting which will cut all frequencies below the selected Hz.... Should be adjustable...


My amp doesn't have a high pass or low pass filter. Then again, it's a PPI Art series so I'm not complaining.
 
Drummer3462 what kind of HU are you using? Does it have an internal crossover / equalizer?

Sony cdx-gt300

Decent deck cost 156.99 new but i think im goin to get the cdx-gt81UW which is gonna run me about $225 but its well worth it
 
Sorry dude, But I have to agree. Sony is really overpriced for the product that they produce. For that deck I wouldn't pay more than 10 dollars brand new. If it was made by alpine, then I would pay that price. But not for sony.

The only way I would buy another sony is if I was selling the car to a junk yard.
 
you guys crack me up... sony sux boo hoo that deck is alot better than the others in the xplod line... read up on it before u point ur finger ... sony makes sub par exept their top of the line decks.
 
I've never had any luck with any of the sony brand (not even their top of the line). I don't mean to bash (I am sorry for that) but as for my personal standards I expect to get what I paid for. If I can can get more for what I paid for ... added bonus. Thats why I am looking into in-dash receivers and not just going out and buying the cheapest one. I want to be sure that the new deck that I am buying is going to be " the best of " for my money that I am willing to spend.
 
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