Sub RMS question/NEW question page2 need you input

[kg1961]

I own a focal 40kx 16" sub
here are the specs
Details:
16" subwoofer with dual 2-ohm voice coils
Aramid fiber/foam/glass composite sandwich cone with butyl rubber surround
multiferrite magnet for precise motor structure linearity
zamak (zinc alloy) basket
power range: 50-500 watts RMS (250 watts per voice coil)
peak power handling: 1,000 watts
frequency response: 25-1,000 Hz
sensitivity: 86.26 dB
top-mount depth: 8-1/16"
sealed box volume: 1.41-2.82 cubic feet

now my amp is rated at 4ohm 500 rms at 12.5v so it should do more than that.
I was told that my amp will not get the sub to move very good and i should be looking for a bigger amp?
my amp will also do 250 @ 2ohm would you run it that way?
let me know
I feel it will be fine maybe not pushed to the max but what focal has asked for

I know there are guy that run 800 watt into a sub that only need 400 with no problem also back in the day i used a m25 to power some 12" subs sounded great

just want to here what everyone thinks

[ttocs]

do they really break down the power rating per coil like that?

[kg1961]

do they really break down the power rating per coil like that?

the 50-500 (250) per ---yes that is all from the manual

[kg1961]

anyone

[stipud]

Dual 2 ohm coils in series = 4 ohms. Your amp makes 500 at 4 ohms. The sub is rated for 500 bridged. So yeah it should be perfect dude, duhhh

[kg1961]

Dual 2 ohm coils in series = 4 ohms. Your amp makes 500 at 4 ohms. The sub is rated for 500 bridged. So yeah it should be perfect dude, duhhh

that what i thought. this is why i bought the amp i own . But i was told be someone that has used alot of focal gear and he said i need 700 to make it sing? I thought WTF why would a high end company want people to not use there gear 100% as I have always used the rms to be what they need

Im just going to try it what the worest thing that will happen I don't like it?but im sure i will the soundstreams spl sound great very punchy just not much low end

[kg1961]

I will be happy thanks guys

[stipud]

that what i thought. this is why i bought the amp i own . But i was told be someone that has used alot of focal gear and he said i need 700 to make it sing? I thought WTF why would a high end company want people to not use there gear 100% as I have always used the rms to be what they need

The difference between 500 and 700 watts is about 1-1.5 decibels. Whoever said that is on crack

Even if you ran 1000 watts we're talking 3dB difference at most. That's just audible enough to hear. Not to mention... when, if ever, do you listen at 100% volume anyways? Odds are that 1000 watt amp would be running 100 watts or less on music at a reasonable volume.

[joerg]

that what i thought. this is why i bought the amp i own . But i was told be someone that has used alot of focal gear and he said i need 700 to make it sing? I thought WTF why would a high end company want people to not use there gear 100% as I have always used the rms to be what they need

The difference between 500 and 700 watts is about 1-1.5 decibels. Whoever said that is on crack

Even if you ran 1000 watts we're talking 3dB difference at most. That's just audible enough to hear. Not to mention... when, if ever, do you listen at 100% volume anyways? Odds are that 1000 watt amp would be running 100 watts or less on music at a reasonable volume.

First of all i´m not on crack for sure!

And i never said that u will need 700 Watts to make it sing, Mike! I said nothing more that u will miss some of the benefits the Focal can throw at your ears if u are running it of 500 Watts only.

Is decibel all that u relate with music? If so buy some SPL subs and a 10kW plus amp and go for it.

The more power u throw at one of those Focals the better and easier the amp manages to control it´s movement. And that´s not some crap i read in a manual, that´s what i know from my former systems and my own experience from owning Focal speakers and subs worth a fortune.

That been said i´m out of the discussion with u Mike! That thread just hit the border! Why asking me if u don´t believe what i tell u. I never forced u to buy another amp. Just told u what i know from using Focal subs for a good decade.

Just one more thing! The recomended amp, from very well known french focal installers, for your sub is the DUAL MONITOR. That´s still an amp from Focal. It´s just a little more expensive. But what do i tell you. You know better already.

Greetz
Joerg

[Bfowler]

yeah, i have experienced that too^ especially on low efficiency subs.

[kg1961]

Im not trying to start a fight or anything maybe i miss understude what you said
but if i read from any company the rms I would or should use a (good amp) clean power at the rated amounts without clipping
if the makers of the item say 500 i would think 500 will work.
I can understand were some people use more power for more control or so the amp doesn't have to work as hard. I get it.

I have and never used big power to get great sound. just me. as you can tell im not a spl guy. I like clean 130-135db and im very happy.
you did say i need the power from a ms2125 at least in another post and the ms2125 will top out around the 710 ... I don't think you are on crack or anything i just understand why I would need more than the rms. thats why this thread is about rms questions.
I understand some subs are underated and some are not. so what you are saying is they are underrated
I have also heard some sub sound great with only 1/2 there rated rms

the focal monitor is a great amp (IMO) but i will not be spending any more cash on this car
I just want good sound. I know power is only part of this so I aksed Tom in my shoe would you make the box bigger or smaller to keep it tight but still good output as focal say 1.41 to 2.6 sealed. I asked you about the size im my first pm to you.
Im making the box about 1.8 with the sub in it and i should be happy

I understand you are not making me change my amps or gear I never said that.
I do ask for your info as in calgary there are very few people with focal gear. and you have used them over the years. I take your word as face value. I concider you a friend as do I think of Tom, thats again why I asked about about the rms and is there anything im missing.

If i pissed you off or anything concider this my sorry.
But it was never to make fun or call anyone out. I just want to make this sub the best i can with what i have

[kg1961]

yeah, i have experienced that too^ especially on low efficiency subs.

these sub are fairly high and efficent

[stipud]

Ah don't take it personally Joerg! It's just my opinion.

When running a 500w amp at 500w versus running a 1000w amp at 500w, the 1000w amp would have more headroom of course. However, with decent amps I doubt you would notice the difference. Especially on bass, it is much harder to hear a subtle difference like transitor linearity! Extra headroom is much better spent on component amplification, where you can notice the peaks of good recordings much better.

I am pretty biased though. I think most stereos these days run way too much power for no good reason. In my experience most people listen to music at moderate levels 99% of the time, and it doesn't take a ton of power to achieve that with any cleanliness! Not to mention running less power means way less power distribution and way lower overall costs.

There are certainly some subs I would agree with you about. Generally low effeciency, long stroke woofers. The Ti Elite for example sounds much worse on anything less than 1000 watts in my opinion, and the best I have heard was pushing well over 2000 watts to one. Similarly I was not impressed with my IDMax on 250w, but I loved it on 1000. So it's very possible that Focal underrated the woofer and it may indeed perform nicely at 1000w.

[Stryker]

Audio Concepts has Focal.....Ask them.

[kg1961]

Audio Concepts has Focal.....Ask them.

ya without paying them money they don't like to tell to much over the phone. I used to know the owner a couple years ago but he has since sold the company. I tried to get info form them when i had all my focal gear but they would not even talk to me as i didn't buy from them

[The Golden One]

this may help you out a little since my critical mass subs are simalar to the focal's for my subs they recommend for 1.0 sealed 1100 watts rms and then for 1.25 sealed 900 watts rms then ported 1.5 ported just 500 watts rms. so basically you may can fine tune the airspace to better match the output of the amp. so if your going sealed just go with a larger encloser then you would have deeper bass and gain some efficency out of the sub at the same time.

[kg1961]

thanks
see this is some of the info i wanted or needed

[12voltjunky]

this may help you out a little since my critical mass subs are simalar to the focal's for my subs they recommend for 1.0 sealed 1100 watts rms and then for 1.25 sealed 900 watts rms then ported 1.5 ported just 500 watts rms. so basically you may can fine tune the airspace to better match the output of the amp. so if your going sealed just go with a larger encloser then you would have deeper bass and gain some efficency out of the sub at the same time.

I would go as far as to say that a sub enclosure can have a larger impact on the overall sound of a stereo than the sub or the amp. Enclosures rarely receive due credit. The smaller the enclosure, the more power the sub should be able to handle. It is my understanding that in a ported enclosure the sub becomes much more efficient and this is why the rms ratings might be lower.

[kg1961]

makes sense I would think even in sealed this should be true?
I know you need more power to move the sub in a small box to get the same out put
im not a spl man...

[The Golden One]

spl has ruined the modern subwoofer and the way everyone looks at bass musical bass has been throw out the window. spl competitors dont listen to music they just want the meter to go higher and could care less about what it sounds like. those few second's to get the meter to go up is not exactly listening to music in fact all they have is some unlisenable crap that makes alot of noise.

[stipud]

Smaller sealed boxes do give more damping, which allows the sub to momentarily sustain more power. However, keep in mind the thermal limits of the woofer remain constant. In fact in a smaller box they can even heat up a little quicker. Of course what is "big" and "small" depends on the woofer as well. Some subs, like the RSDC's, like more conventional smaller box sizes, while the Xenons like much larger box sizes in general. For a Xenon 12 a box of 1.25 cuft is very small while for an RSDC 12 that's pretty large.

What I generally aim for is a Qtc of .707, aka "critically damped". This is usually the default "best sounding" Q for a sealed woofer, although depending on the sub a higher or lower Q can sound good as well. Usually this ends up being the largest sealed box size recommended by the manufacturer, which is what I would suggest sticking with unless you have T/S parameters and speaker graphing software. The smaller SPL sealed alignments usually inrease the Qtc, thereby giving you a peak in the response with quicker roll off in low end bass.

http://www.bcae1.com/spboxad2.htm

[kg1961]

I can't make it work im missing some items

fs 34.6hz
vas 2.28ft3
qts .82
qes .97
qms 5.3
RE 4.2 in series
sd 124.65in2
mms .65lb
le 4.2mH (in series)
res 22.95ohms
Bl 16.71N/A (in series)

that all the spec i can find for this sub

[dwnrodeo]

You should be able to model the sub with those specs.

[Stryker]

spl has ruined the modern subwoofer and the way everyone looks at bass musical bass has been throw out the window. spl competitors dont listen to music they just want the meter to go higher and could care less about what it sounds like. those few second's to get the meter to go up is not exactly listening to music in fact all they have is some unlisenable crap that makes alot of noise.

Ruined the "modern subwoofer" how so? I rather like my modern subwoofers. If I recall PG introduced one of the first high wattage amps (The 2250) so it has only progressed to this point. Blame them to a point You must have subs to handle the enormous amount of wattage that is attainable by todays amps.
Of course SPL competitors don't setup there cars for music they play test tones in the 40-60 Hz range. One note wonders if you like, They are not designed for music at all. You can still have a very loud sub setup, and be able to listen to a variety of music with SPL oriented subs. Just because it's loud doesn't mean its lousy sounding....

[fuzzysnuggleduck]

I was under the impression that most subwoofers and driver RMS ratings were based on thermal dissipation capabilities, not something arbitrary like "they need 500w to sound good" but I really don't know anything so please don't listen to me!

Something along the lines of... 500W RMS rating = "This sub will not melt with 500W RMS applied to the VC for 72 hours straight" or whatever.

But again, it's highly likely that I don't know shit.