15" btl on 1870 rms, enough power?

[antonmiller 8]

well as the title states, i want to know if it will be enough power to run the 15" BTL untill i get more money for a bigger amp. basically will it hurt the BTL to be underpowered? it will be in a ported box tuned to 32-35 hz not sure yet. probly around 4.5 cu ft

and yes the rockford does that much power. its on my spec sheet i got with it. 1870 at 1 ohm, with a THD of .22% at rated power (im guessing that means at 1500 rms)

also will it be a big upgrade in spl from a 12" BL, on the same amp? (not running at full power, probly around 1200 right now)

[dbjunior 0]

running less than rated will never hurt a sub

[RamenNoodles 0]

That is fine. You dont need to throw an exuberant amount of power on them to hear them shine. Make the box a little bigger and you will enjoy the results.

[- Nickelz N Dimez - 0]

You will probably like how it sounds..

[ABXX49 20]

Perfectly fine! You probably won't notice the difference between 1875 and 2000 actually.

[slim2fattycake 85]

dont go crazy on the gain though because you don't want to send clipped signals to the sub, but under powering is fine.

Edited April 15, 2009 by phi

[antonmiller 8]

wow thatnks for the replies guys. i was expecting so many so soon.

so what would you suggest on box size for the power?

also it will be front firing into the cabin of my cavalier, the trunk sealed off.

Edited April 15, 2009 by Anton Miller

[BKOLFO4 29]

The box you suggested - 4.5 ft tuned to 32-35 will work great.

Brian

[Smallk07 0]

thats funny im bout to upgrade from a bl to a btl witht the same amp

[Maddenkid2011 3]

The power output of an amplifier should be roughly matched to what the amp will be used for and what speakers it will be driving. Oddly enough, the most common problem with matching speakers and amps is using an amp that is too weak to power the speaker. When an underpowered amp is used to power a speaker, the listener tends to turn the volume up higher in order to get more output of the amplifier. Eventually the amplifier runs into its limit and begins to distort. This distortion can cause the output from the amplifier to become DC for short periods of time and DC signals of even low power can destroy a speaker. Underpowering a speaker in this way can be more dangerous than overpowering it! Also more power is usually necessary when powering subwoofers because of their large size and excursion. Do not plan on using an amp of less than 75watts per channel to drive a subwoofer. The converse holds true for higher frequencies (midrange and treble) only 25-50watts per channel are necessary to drive speakers in those frequency ranges, however more power will not hurt, it just probably will not be used. Another factor in power output is stability in low resistance loads. Sometimes you can wire mutiple subwoofers to a single channel on an amplifier but the amp will have to work harder to drive this kind of load. Many moderately priced amps can drive loads as low as 2 ohms or less, with 4 ohms being the typical load of a single speaker.

THD (Total Harmonic Distortion) is a spec that often shows up with the power output spec. An example would be "45wattsx2 @ 0.01% THD" This spec says that at an output level of 45watts into each channel the THD will be no more than 0.01%. Sometimes manufacturers will quote the power spec at a THD of 1%. Be wary of this, 1% THD is poor and either implies that the amp is not very high quality or that the manufacturer is artificially inflating the power output spec by running the amp into a higher distortion region where it does produce more power but more distortion as well. Either way it is a sign of a poor amp or marketing that decieves. Anything less than 0.1% is negligible.

So you CAN hurt a sub by underpowering it. And in my opinion if your a not jakcalope (no offense) and dont crank the amp to get more output then your not gonna hurt the sub.

Any questions?

Tyler

Edited April 15, 2009 by Maddenkid2011

[BKOLFO4 29]

Pretty much everything you just said is WRONG. Should not have posted.

Do a little more reasearch and then come back!!!!!!!

[bread0710 0]

The power output of an amplifier should be roughly matched to what the amp will be used for and what speakers it will be driving. Oddly enough, the most common problem with matching speakers and amps is using an amp that is too weak to power the speaker. When an underpowered amp is used to power a speaker, the listener tends to turn the volume up higher in order to get more output of the amplifier. Eventually the amplifier runs into its limit and begins to distort. This distortion can cause the output from the amplifier to become DC for short periods of time and DC signals of even low power can destroy a speaker. Underpowering a speaker in this way can be more dangerous than overpowering it! Also more power is usually necessary when powering subwoofers because of their large size and excursion. Do not plan on using an amp of less than 75watts per channel to drive a subwoofer. The converse holds true for higher frequencies (midrange and treble) only 25-50watts per channel are necessary to drive speakers in those frequency ranges, however more power will not hurt, it just probably will not be used. Another factor in power output is stability in low resistance loads. Sometimes you can wire mutiple subwoofers to a single channel on an amplifier but the amp will have to work harder to drive this kind of load. Many moderately priced amps can drive loads as low as 2 ohms or less, with 4 ohms being the typical load of a single speaker.

THD (Total Harmonic Distortion) is a spec that often shows up with the power output spec. An example would be "45wattsx2 @ 0.01% THD" This spec says that at an output level of 45watts into each channel the THD will be no more than 0.01%. Sometimes manufacturers will quote the power spec at a THD of 1%. Be wary of this, 1% THD is poor and either implies that the amp is not very high quality or that the manufacturer is artificially inflating the power output spec by running the amp into a higher distortion region where it does produce more power but more distortion as well. Either way it is a sign of a poor amp or marketing that decieves. Anything less than 0.1% is negligible.

So you CAN hurt a sub by underpowering it. And in my opinion if your a not jakcalope (no offense) and dont crank the amp to get more output then your not gonna hurt the sub.

Any questions?

Tyler

i ran a kicker zx400.1 to an L7 12in (rated for 750) for almost a yr and i never blew anything? ialso clipped the chit out of it b/c i didnt know what i was doing. still didnt blow anything?

Edited April 15, 2009 by bread0710

[Duran 387]

MaddenKid, you can run any amplifier on any sub and not blow it from clipping. CLIPPING DOES NOT BLOW SPEAKERS. Irresponsible people in control of the volume knob do.

[Maddenkid2011 3]

I defintely didnt say anything about blowing speaker. I was explaining ways that it could HURT a sub. You just said that irresponsible people with the volume knob is what hurts a sub. I was explaining HOW it hurts the sub. NO where did i say that DON'T DO IT YOU WILL BLOW YOUR SUB. Clipping and DC currents can HURT a sub not ruin it instantly. I said that doing those things for a while on the sub will be the downfall not just one time. Reread that and try to understand it

[antonmiller 8]

i always thought that a THD of under 1% was a good thing. am i wrong? lol

so does this mean that the thd of my amp is bad?

[seanbw 1]

Pretty much everything you just said is WRONG. Should not have posted.

Do a little more reasearch and then come back!!!!!!!

x2

maddenkid, it's apparent that you are trying to help but spreading misinformation is a disservice to you and the rest of the members on this forum.

[Maddenkid2011 3]

Your right

BELOW .1% is great

Above .1 is okay

0.2% is a little sketchy

[seanbw 1]

and to the OP, 1870watts is more than enough to power your woofer and destroy most stock electrical systems

finally, to the guy swapping from a bl to a btl, if you make sure the btl is an optimal enclosure it will be substantially louder than the bl with the same amp due to the higher efficiency of the btl, enjoy!

[Punkeyboozter 19]

not that i want to put a stick in your spokes but...

Newbie

Group: Members

Posts: 25

Joined: 27-February 09

Member No.: 7,692

Any-way speakers are always blown by over powering them. If distortion blew speakers then we would not have rock music. Actually distorion can sound good if done right. Any how with clipping your amp will pull more power and if its a good amp potentially put out 1/4-1/2 more power if your amp does not go first...This could also blow your sub(1/4-1/2 more then rated power) <-- that is if your amp is evenly matched to your sub, imagine what can happen if you use a bigger amp. Also, you would need the electrical to back it up.

Speakers are dumb and will do what you tell them..If you give them little power they will give little output and visa versa. There are a lot more to it, but hope my confusing attempt to try and explain it helped some-what.

[Maddenkid2011 3]

You right Punkeyboozter just because i JUST found this forum means that I have ABSOLUTELY NO KNOWLEDGE of anything that has to do with speakers. I should just go crawl in a hole and die.

Edited April 16, 2009 by Maddenkid2011

[BKOLFO4 29]

Don't crawl in a hole, but also don't post info that is not quite true.

Let's look at a few things here:

The power output of an amplifier should be roughly matched to what the amp will be used for and what speakers it will be driving. Oddly enough, the most common problem with matching speakers and amps is using an amp that is too weak to power the speaker.

Does not matter. May not get the max performance out of a sub, but a 1000 watt amp will work fine with a 2000 watt speaker. The real truth is that many times a sub will not even mechanically handle its rated power because of the box it is installed in and because people do not use subsonic filters correctly in ported boxes.

When an underpowered amp is used to power a speaker, the listener tends to turn the volume up higher in order to get more output of the amplifier. Eventually the amplifier runs into its limit and begins to distort. This distortion can cause the output from the amplifier to become DC for short periods of time and DC signals of even low power can destroy a speaker. Underpowering a speaker in this way can be more dangerous than overpowering it!

You are correct, people tend to do this, but clipping does not damage the speaker. When a signal is clipped, the RMS power will become higher. In theory, it could almost match the peak power if the amplifier is not destroyed. This increase in RMS power is what actually damages the speaker.

Here is a nice read:

http://www.forceaudio.com/showthread.php?t=15

Also more power is usually necessary when powering subwoofers because of their large size and excursion. Do not plan on using an amp of less than 75watts per channel to drive a subwoofer. The converse holds true for higher frequencies (midrange and treble) only 25-50watts per channel are necessary to drive speakers in those frequency ranges, however more power will not hurt, it just probably will not be used. Another factor in power output is stability in low resistance loads. Sometimes you can wire mutiple subwoofers to a single channel on an amplifier but the amp will have to work harder to drive this kind of load. Many moderately priced amps can drive loads as low as 2 ohms or less, with 4 ohms being the typical load of a single speaker.

Not much to say there. The power required is based on your needs. Some like headroom, others like to max everything out. Some like loud, some do not. . .

THD (Total Harmonic Distortion) is a spec that often shows up with the power output spec. An example would be "45wattsx2 @ 0.01% THD" This spec says that at an output level of 45watts into each channel the THD will be no more than 0.01%. Sometimes manufacturers will quote the power spec at a THD of 1%. Be wary of this, 1% THD is poor and either implies that the amp is not very high quality or that the manufacturer is artificially inflating the power output spec by running the amp into a higher distortion region where it does produce more power but more distortion as well. Either way it is a sign of a poor amp or marketing that decieves. Anything less than 0.1% is negligible.

You are correct, some companies do use higher distortion ratings to inflate power ratings. They also use peak power and will even rate at a higher single frequency. But, 1-2% (not 0.1-0.2%) on a class D sub amp is pretty much acceptable to most of the bassheads that come here asking if they can use 1500+ watts on a BTL

So you CAN hurt a sub by underpowering it. And in my opinion if your a not jakcalope (no offense) and dont crank the amp to get more output then your not gonna hurt the sub.

That statement should say - You can hurt a sub with an amp rated at less than the subs rated power, but the word "underpowering" is not the correct word for what actually damages the sub.

[hless421 0]

Im gonna use that excuse if i get stopped for playing too loud. But officer, it's a bad idea to turn it down because my sub is then being underpowered and thats not good.