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SpeakerBoy

Amplifier run below impedance question

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I forgot to rewire the BTL to 4ohm when I swapped it with my 15's in the HT, and while I was doing so, I began to wonder, if my amp is only 4ohm stable, how does it function exactly, under 4ohm? (I had it wired at 1ohm for the Neer)

For example, if you sweep the box, and you measure your entire playable range, and it never exceeds the rated RMS of the amp, say you're wired at one quarter rated minimum like me, and you have it set conservatively, and safe, does that prevent premature failure that low impedance is known for? Is that how people run amps at .25 daily and shit since it's only passing the rated amount of power through? I always assumed they did that for comps, and ran it super low because of a peak in impedance at their loudest frequency to maximize output for that single note. Demos were just showing off. 

I've got no interest in doing so, I've way to heavy a hand on the knob; just wondering how it works. 

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Competitors wire low because they can actually measure there impedence changes, and still be safely in the recommended range. But their playing sign waves not 100 different kinds of music. I never ever wire below impedence your basically shorting the amp out at certain frequency's.

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That's what I just said lol

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6 hours ago, SpeakerBoy said:

That's what I just said lol

You also answered your own question. If it's set safe, then obviously it's not gonna over heat if very little current is going through it, so what exactly is your question, or are you just looking for confirmation?:fing05:

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4x the current at the same voltage.  Hope your amp has both a current limit shut down as well as thermal.  Or more logically rewire that shit pronto

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27 minutes ago, ///M5 said:

4x the current at the same voltage.  Hope your amp has both a current limit shut down as well as thermal.  Or more logically rewire that shit pronto

Is that a common protect feature on car amps?

I rewired mine lol, I hit a low note and it hiccuped and I suddenly remembered. 

I think my amp has a no clip feature, whatever that's called. I can't throw it into clipping no matter how high I crank it. It stops at 45v rms and that's that. 

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21 minutes ago, ///M5 said:

4x the current at the same voltage.  Hope your amp has both a current limit shut down as well as thermal.  Or more logically rewire that shit pronto

This is sound advise (pun intended). Think of impedence like a pipe, and a amp trying to feed water, (rms) to this pipe, and current as water pressure. As you play music this pipe is getting bigger and smaller all the while your amp is trying to supply enough water to keep it full, so even if you slow the rate of flow it's gonna have a hard time keeping the pipe full (current). I have seen it done but sometimes it causes heat and failure. 

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I know it's harder on the equipment but I was trying to understand in what way; everyone knows it's bad. I wanted to understand. 

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6 minutes ago, SpeakerBoy said:

I know it's harder on the equipment but I was trying to understand in what way; everyone knows it's bad. I wanted to understand. 

Ow ok. Yea man if you care about your stuff, I would wire to high, then to low. You can't hurt a thing going higher, but your asking a lot of your amp going lower. Your amp will be safe, and you get the added sound quility to boot, all your giving up is a tiny bit of wattage which you probably want hear a difference anyways.

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1 hour ago, SpeakerBoy said:

Is that a common protect feature on car amps?
 

Perfect implementations?..never.

Exactly why it is idiotic to play the impedance curve game and wire low.  (I realize you didn't do this on purpose.)  Competition wise it isn't as nasty since the situation is normally reduced to a frequency with it's associated impedance allowing some optimization of the current & voltage to fit within the amps capability.  This does assume the operator is competent.

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Thanks for entertaining my curiosity =]

Makes the A6000GTI all the more sexy to me. 6k @ 4ohms.... *shiver*

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People also generally just do not understand that matching RMS ratings, wiring below the rated impedance of the amp, or replacing their 2000 watt amp with a 3000 watt is simply not really gaining them much, if anything at all. And yes I used to believe it too. 

Doubling power only gains a theoretical 3db of output, barely any real audible difference. Often times the gain is not even close to that much.  Using more power to try to make gains in output is the most expensive and least efficient way to do so.  Generally when it comes to output cone area is king followed by proper and/or efficient enclosure design and construction. 

I know you weren't asking about it in this particular aspect but I still felt it was worth mentioning. 

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The only clarification I'd add Shannon is that 

2 minutes ago, altoncustomtech said:

Generally when it comes to output cone area is king followed by proper and/or efficient enclosure design and construction. 

those are ideas are not exclusive so using the word "follow" I don't agree with...but I know you don't either and just typed it that way.

It is a MUST to have a reasonable enclosure design no matter the cone area.  

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Perfect segway

 

I've been wanting to do a high surface area, low power build for quite some time but I've been afraid to commit to the idea because of how attached I've gotten to drivers like my BTL.

Something like 6 dcon 15's sealed.

Would that net me more "felt" bass and low end extension than continuing down my single 18 path? 

 

My brother's car was nasty loud on 2k rms, you couldn't tell if you were breathing on mid to high notes and that was five Memphis 12's sealed. I miss being choked out.

Edited by SpeakerBoy

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I'm using that very concept in both my builds. 2 13w7's, one HD1200/1, and 2 sundown team 12's, on one crescendo 3500. I do plan to add power, but for right now it's ok, even at half power on both. Well they where I should say, I'm waiting on boxes for both my cars. But they where installed that way in my last 2 cars.

Edited by Billy Jack

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19 hours ago, ///M5 said:

4x the current at the same voltage.  Hope your amp has both a current limit shut down as well as thermal.  Or more logically rewire that shit pronto

or 2x the current at the same wattage, probably more relevant, still probably as dangerous

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Ran at .25 nominal, daily in the blazer for about 4 months. Got those two boards hot as fuck. Also, and bare with me. The drivers control was shitty. Im no guru, but, I guess dampening factor flies out of the window wired full retard. I just didnt like the way the drivers behaved. I did nuke both boards in that time. And i hated the way the drivers moved when i leaned on it hard. Ill never do that again, for competing or not. Certainly not for daily.

Had those repaired, and added 2 more, and ran all of them at .7 nominal, daily. Never had a issue there, and control was MUCH MUCH gooder. 

Currently run .5 nominal, daily in the burb now. 4 of the 6 in the burb, are from the blazer build. Still chugging.  Have been for a good amount of time. Boards get hardly warm at all. We do NOT know our rise, or any of that. But, im confident they are fine, control is great, playing 20hz for over 30s full, and have not ran into any soft part issues.

Thermally, we arent even worried. Where i think we are making OK power, thermal we dont even worry. Drivers hardly get warm even after long abusive play.  i would expect some issues to arise though, when we add power. We may have to shrink the sealed side. We will see. 

Its one of those things. You want to make power, but keep shit working, and be reliable. Those that wire in the dirt for burps, usually know exactly where they are rising to, and burp at tune, which is where your driver should move least. So, mechanical should hold OK, you know, unless your throwing ungodly amounts at the driver, which a lot do. And its only for 3 seconds.

I see many many in the lanes,now a days, that have a switch, or physically wire up and down for when they burp, then demo/play music. 

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Some amps on proper electrical can handle low impedence loads better then others. I would feel much safer wiring a mmats or DD amp at .5ohm, then I would say a hifonics or  Audiopipe. My nephew wired his 3200 watt Collossus to .5ohm and it lasted a little over a week. Luckily sonic electronics took it back and sent him a brand new unit no questions asked. Now he has a sundown saz2500 wired to .5ohm on the same subs, same everything and it's been going strong for over a year and a half. It does get hot but nothing like the Collossus, you could have fried eggs on it.

Edited by Billy Jack

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