When looking at sub amps..what specs most important?

[kingsxman 10+ year member]

I know about ohms, wattage, etc...what I dont know about is damping factor, signal to noise and input sensitivity. What do these numbers mean? I'm pretty sure a higher number is better on signal to noise....

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[Raven 10+ year member]

Haha, nice user title. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

Just like in subs, there is no "most important" spec to look at. The most important thing to do is look for one that will provide the power you want at the impedance you need. Just remember the basics: If it's too good to be true, it is; You get what you pay for; and when in doubt, ask.

 

[kingsxman 10+ year member]

Yeah, I hear you. However, the reason I ask is because I want an amp thats clean and has some punch. I remember that some things like Q and slew rate contributed to the overall punch of the amp...but I forget how. Maybe Damping factor too.

I dont know. Just trying to make an informed decision.

And yes...KingsX rocks!

 

[squeak9798 5,000+ posts]

Yeah, I hear you. However, the reason I ask is because I want an amp thats clean and has some punch. I remember that some things like Q and slew rate contributed to the overall punch of the amp...but I forget how. Maybe Damping factor too.
I dont know. Just trying to make an informed decision.

And yes...KingsX rocks!

Amps don't really have a "Q" (though your subwoofer in the enclosure has a Qtc, which can affect the "punchyness", which is what I presume you are thinking about).

Slew rate is basically a non-issue for a subwoofer amp (and any amp worth it's weight in dog poop should have sufficient slew factor at any frequency).

Damping factor, for the most part, is overrated as a specification. Again, any amp worth it's weight in dog poop will have sufficient damping factor.

SNR....again, overrated as a specification, especially in subbass applications. Any amp worth it's weight in.......well, you get the idea here //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

Input sensitivity just gives you an idea of what input voltages work well with the amp. A range of, say, .2v to 8V means that you can obtain full power output from the amp with that range of input voltages from the HU.

As Raven said.....just find a good quality amp that makes the power you need into the impedance you have with features you want and cosmetics and a warranty that satisfies you.

 

[PatFitz9 10+ year member]

http://www.crutchfieldadvisor.com/learningcenter/car/amplifiers_glossary.html that might help a lil

 

[squeak9798 5,000+ posts]

http://www.crutchfieldadvisor.com/learningcenter/car/amplifiers_glossary.html that might help a lil

....

Damping FactorThe ability of an amplifier to control the movement of a speaker — the higher the damping factor, the greater the accuracy. Damping factor is calculated by dividing the speaker impedance by the output impedance of the amplifier. An amplifier's damping factor will decrease as the speaker's impedance decreases — that's why an amp running at 4 ohms will provide tighter bass than at 2 ohms.

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Don't put too much faith into the descriptions they give //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

It isn't the ability to control the movement of the speaker, it's the amps ability to maintain a constant output voltage as impedance changes.

Likewise, there is a threshold for damping factor (aswell as slew rate and SNR, for example) where going above that threshold does not increase "performance" any. For damping factor, most agree this is around 10 to 20. Going any higher won't yield you any benefits.....while a DF of 200 may be higher numerically than 100, you won't hear a difference between them because they are both over the threshold. And, again, most any amplifier will have sufficient damping factor to where it is a non-issue.

Same thing with slew rate.......it's essentially the maximum rate of change that an amplifier can reproduce. If an amplifier has a sufficient "rate of change" for the bandwidth of frequencies you are using it to reproduce, going any higher isn't going to yield any benefit. Once it has enough, it has enough....that's all that is needed. And again, most any amplifier will have sufficient slew rate.

And to clarify my comment on "Q".....damping factor is essentially a "Q", but with the way you worded your statement it seemed like an enclosures "Qtc" (commonly referred to simply as "Q" sometimes) was what you were thinking of (and really IS what is important to fast, punchy bass....along with having good mids).

So, as I said....just find a good quality reliable amp that makes the power you need into the impedance you have with features you want and cosmetics and a warranty that satisfies you.