I'm still a little wary...

[Photonfanatic 10+ year member]

Hi all. Had a thread about this issue before, but now its coming down to it. I'm going to install my sub and amp either tonight or tomorrow. But I'm still a little wary of doing it with the gear that was recommended by a few of the members here. My only concern is the power that the amp is going to be sending to my sub.

I have the 4-Ohm sundown audio SA-8 subwoofer, which I will be powering with a Nakamichi PA-1500 amp. That's a 1,200 watts RMS amplifier. That sub is only 400 watts RMS. However, everyone says that sub is dramatically underrated. So lets say we can tack on another 200 watts RMS to the sub. That's quite a lot. Even buy "underrated" standards, don't you think? Or am I wrong here?

So even if that sub can handle a real life 600 watts RMS, I'm still going to be pushing about 800 watts out to it. Correct? I really don't want to blow this $150 sub guys. Is there some way I can perhaps... I don't know... throttle back the amp in some way? Should I set the gain at zero? Maybe that would help? Can anyone give me any real assurance that this little sub can really take that kind of pounding and still live a long life?

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[Knowmadic 10+ year member]

I find it a little odd someone recommended you a 1200 RMS amp for a 400RMS sub.. I'm sure you could have founded something reasonable in the price range for a 600-800RMS amp. Oh well, whatever the reasoning is, you have it now. You're going to have to be extremely careful when you begin setting the gain. Before any electrical is connected/turned on make sure that gain is at 0. SLOWLY turn it up, too much and that thing will be toasty. You're honestly not going to have to turn it up at all so just a little bit up off 0 should be more then fine. Try setting with a DMM and back it off a little bit what that tells you to be safe.

 

[IonRL205 10+ year member]

Just set your gain with a DMM and use for the formula to set it around 600 watts.

600 x 2 ohm = 1200

sqrt of 1200 = 34.64

When you set your gain with the DMM, raise it up until the DMM reads 34v

 

[Photonfanatic 10+ year member]

I find it a little odd someone recommended you a 1200 RMS amp for a 400RMS sub.. I'm sure you could have founded something reasonable in the price range for a 600-800RMS amp. Oh well, whatever the reasoning is, you have it now. You're going to have to be extremely careful when you begin setting the gain. Before any electrical is connected/turned on make sure that gain is at 0. SLOWLY turn it up, too much and that thing will be toasty. You're honestly not going to have to turn it up at all so just a little bit up off 0 should be more then fine. Try setting with a DMM and back it off a little bit what that tells you to be safe.

I'm afraid I don't know what a DMM is. I do have an Oscilloscope that I bought off of ebay. Would I be remiss if I just let the gain at zero? Is there any real reason for me to use the gain setting at all? Am I going to somehow lose sound quality or something, if I leave the gain at zero? Cause in this instance, from what little knowledge I do have on the subject, it sounds like that might be the best idea.

Just set your gain with a DMM and use for the formula to set it around 600 watts.

600 x 2 ohm = 1200

sqrt of 1200 = 34.64

When you set your gain with the DMM, raise it up until the DMM reads 34v

But its a 4-ohm sub. Not sure if that means anything to your calculations. I'm a pretty big noob to all this.

 

[IonRL205 10+ year member]

I'm afraid I don't know what a DMM is. I do have an Oscilloscope that I bought off of ebay. Would I be remiss if I just let the gain at zero? Is there any real reason for me to use the gain setting at all? Am I going to somehow lose sound quality or something, if I leave the gain at zero? Cause in this instance, from what little knowledge I do have on the subject, it sounds like that might be the best idea.


But its a 4-ohm sub. Not sure if that means anything to your calculations. I'm a pretty big noob to all this.

The SA 8s are dual 4 ohm, which means there are two 4 ohm voice coils. With that being said, you can wire your sub to 8 ohms or 2 ohms.

8 ohms wouldn't give you much power, so 2 ohms is the way to go. I did my calculations based on you wiring the sub to 2 ohms, which is connecting both of the positive terminals together, and both of the negative terminals together, then run a wire from a positive terminal to the positive on your amp, and run the negative from the a negative terminal to the negative terminal on your amp.

DMM = digital multimeter

Just read that you have an Oscope, that would be the best way to set your gains..unfortuantely I dont know how to use one and can't help you there lol

 

[Photonfanatic 10+ year member]

You just get the numbers for the wave that you're working with and put them in the scope. Then look at the waves themselves on the screen and make sure they don't go up past the line, which is the numbers you set. If they do, you get clipping and distortion and all that mess. I can use the scope and the DMM if need be. But others have told me that the sub probably won't ever even pull the max power that it can from that amp, if I just don't turn it up so loud that it needs to. So in other words, that sub will be plenty loud without me ever having to crank it so high that I might damage it. I was thinking that whatever power you're running, that's what's being fed to the sub at all times. And thus, you don't want to overpower its RMS.

 

[IonRL205 10+ year member]

You just get the numbers for the wave that you're working with and put them in the scope. Then look at the waves themselves on the screen and make sure they don't go up past the line, which is the numbers you set. If they do, you get clipping and distortion and all that mess. I can use the scope and the DMM if need be. But others have told me that the sub probably won't ever even pull the max power that it can from that amp, if I just don't turn it up so loud that it needs to. So in other words, that sub will be plenty loud without me ever having to crank it so high that I might damage it. I was thinking that whatever power you're running, that's what's being fed to the sub at all times. And thus, you don't want to overpower its RMS.

The amp does 800 @ 2 ohms, so I guess with box rise and whatnot you'd probably be fine.

 

[wickedwitt 10+ year member]

The amp does 800 @ 2 ohms, so I guess with box rise and whatnot you'd probably be fine.

This. Don't send clipping and the SA should actually take the entirety of the amp. Entirety doesn't mean gain set to max, it means gain set maximum before clipping.

 

[FamousMassacre 10+ year member]

Hi all. Had a thread about this issue before, but now its coming down to it. I'm going to install my sub and amp either tonight or tomorrow. But I'm still a little wary of doing it with the gear that was recommended by a few of the members here. My only concern is the power that the amp is going to be sending to my sub.
I have the 4-Ohm sundown audio SA-8 subwoofer, which I will be powering with a Nakamichi PA-1500 amp. That's a 1,200 watts RMS amplifier. That sub is only 400 watts RMS. However, everyone says that sub is dramatically underrated. So lets say we can tack on another 200 watts RMS to the sub. That's quite a lot. Even buy "underrated" standards, don't you think? Or am I wrong here?

So even if that sub can handle a real life 600 watts RMS, I'm still going to be pushing about 800 watts out to it. Correct? I really don't want to blow this $150 sub guys. Is there some way I can perhaps... I don't know... throttle back the amp in some way? Should I set the gain at zero? Maybe that would help? Can anyone give me any real assurance that this little sub can really take that kind of pounding and still live a long life?

That sub could take 1200rms

 

[sbarber82 10+ year member]

Don't worry bud, like others have said it will handle that amp @ 2ohm no problem. Turn your volume to the highest you listen to it with no bass boost, sub level at 0 on the H/U and flat EQ and set the gain with the DMM to 34V with the sub disconnected from the amp. Download a 50hz test tone off the internet to run on repeat while you set the gain. Then set your SSF (sub sonic filter) on the amp to 28hz or so and you should be on your way to some clean bass!

Enjoy!

 

[Photonfanatic 10+ year member]

That sub could take 1200rms

Thanks for all the help everyone. I really appreciate it. That said, I'd like to reply to this quote. Why, oh why, would they rate the sub so low? I just don't get it. I mean I know they do it, but why? If it could take 1200 watts RMS, what's the point in rating it a 400? You're going to get your average joe who just reads the packaging on the products he buys, and say "Well, better get me an amp that's gonna be 400 watts at 2-Ohm, then."

Which if it really can take 1200 watts RMS no problem, then average joe is losing out on a lot of his sub's potential. Right? Maybe I'm missing something here.

 

[Griff1220 10+ year member]

You should be fine with that combo. If you can, I highly suggest investing in a DMM (probably around 20-30 bucks at like autozone or wal mart). At 2 ohms, that amp is rated at 800w rms, now with box rise you probably wont see full power for any considerable length of time. As long as you aren't clipping, that sub will handle that power and love it. I have a buddy running two sa-8s on an AQ2200.1 (rated at 2200w rms at 1 ohm) wired to 1 ohm. Now again, with box rise he isn't seeing the full 2200 watts, but nonetheless those subs handle it just fine. Be moderate with the gain and your sub won't blow. Set it with a DMM like stated by numerous members here. If you ever at any point start smelling the sub, it means you need to back the gain down a tad. Honestly, I know how stressful it is being new because I've only been in the car audio scene for about 2 years and I can remember the concern that I used to have, but the advice from more experienced members here is good advice. Your sub should handle that setup no problem.

 

[RicksI30 10+ year member]

The amp does 800 @ 2 ohms, so I guess with box rise and whatnot you'd probably be fine.

Don't ever count on "box rise" (which I'm assuming that you are referring to impedance curve) unless you are playing test tones.

 

[FamousMassacre 10+ year member]

Thanks for all the help everyone. I really appreciate it. That said, I'd like to reply to this quote. Why, oh why, would they rate the sub so low? I just don't get it. I mean I know they do it, but why? If it could take 1200 watts RMS, what's the point in rating it a 400? You're going to get your average joe who just reads the packaging on the products he buys, and say "Well, better get me an amp that's gonna be 400 watts at 2-Ohm, then."
Which if it really can take 1200 watts RMS no problem, then average joe is losing out on a lot of his sub's potential. Right? Maybe I'm missing something here.

It's a 600rms(or 500?) Sub, but because of how well it's built it can take more power but you're stressing the parts more than what's recommended.

Okay here's an analogy.

The 500rms is like a person walking, they can do it for a long time

900rms is a person jogging, they can do it for a little less than walking

1200rms would be a person running they can't do it as long as a person jogging.

A person can do all of those things just not for the same amount of time.

900rms would be perfectly safe daily. I'm sure you could do 1200 daily, but I'd back off a little less than that.

 

[RicksI30 10+ year member]

Thanks for all the help everyone. I really appreciate it. That said, I'd like to reply to this quote. Why, oh why, would they rate the sub so low? I just don't get it. I mean I know they do it, but why? If it could take 1200 watts RMS, what's the point in rating it a 400? You're going to get your average joe who just reads the packaging on the products he buys, and say "Well, better get me an amp that's gonna be 400 watts at 2-Ohm, then."
Which if it really can take 1200 watts RMS no problem, then average joe is losing out on a lot of his sub's potential. Right? Maybe I'm missing something here.

It's the "oh my God it's underrated and can take twice it's rated power" sales approach. People think that they are getting a better deal because they can apply more power than it is rated for. Nothing against sundown or the sa, as it obviously works.