RMS Rating

[Blaze]

Hey people, my mate bought a set of JVC CS-FS6 splits for his car, the max power rating is 300W but they don't specify an RMS rating. I've looked all over the net for the rating including on the JVC website but they don't state it either. If anyone has a set of these speakers and knows the RMS rating could you tell us what it is or if anyone knows where I can find it...

Thanks heaps.

[Bluish]

normally RMS power rating will be half the max rating, but 150w RMS seems abit untrue, i'll say 80WRMS on tap should be enough to drive this speaker sweet enough.

[mrwillz]

mi getting those splits!!!!!!!!

i'll only b running of HU tho, cos im poor
i dun fink 150rms is tru
more like 60-80rms

[mrwillz]

btw, if u hooked them up, how r they????

[J-MuN]

normally RMS power rating will be half the max rating, but 150w RMS seems abit untrue, i'll say 80WRMS on tap should be enough to drive this speaker sweet enough.
That's not true. RMS rating is not half the PMPO. That's what alot of people say but it isn't true. It may seem that way but it isn't all true.

The JVC Splits can most likely handle 50-60rms.

[Blaze]

We haven't hooked them up yet, but when we do I'll tell you how they go.

At the moment he has a HU @ 45w and a Kicker impulse IX404 amp @ 45W RMS. With these power ratings he doesn't want to hook the speakers up unless he's sure that they will run and that the speakers won't get damaged due to underpowering. So if he can't power the speakers with that amp, which amp would he have to get considering he has a minimal budget.

Thanks guys and have a verry merry christmas.

[Bluish]

That's not true. RMS rating is not half the PMPO. That's what alot of people say but it isn't true. It may seem that way but it isn't all true.

The JVC Splits can most likely handle 50-60rms.

thats right, just a rough comparison, although theres no correlation btw RMS and PMPO or Peak Power, thats why i said feed 80WRMS(or 70WRMS) to the speaker, the most speaker will sound better if we power them abit more than they can actually handle, right? just my opinion. :D

[mrwillz]

can speakers get damaged if underpowered, eg if i run the same splits off HU.

[J-MuN]

can speakers get damaged if underpowered, eg if i run the same splits off HU.
Speakers can not be damaged if underpowered. Doesn't really make sense if they did get damaged when a lower power is fed instead of the recommended power.

[mrwillz]

oh ok
well
i've decided to get the jvc as-ax3300 2x65rms neway

thanks for clearing up that theory j-mun
i didnt think it wud b true

[aka_NSX]

Speakers can not be damaged if underpowered. Doesn't really make sense if they did get damaged when a lower power is fed instead of the recommended power.

who said speaker can not be damaged if underpowered ??? its much easier speaker to be damaged if underpowered rather then overpowered, coz when the amp is underpowered is much easier to clip then voice coil is getting hot and u will burn the voice coil and void ur warranty for the speaker as well

[J-MuN]

who said speaker can not be damaged if underpowered ??? its much easier speaker to be damaged if underpowered rather then overpowered, coz when the amp is underpowered is much easier to clip then voice coil is getting hot and u will burn the voice coil and void ur warranty for the speaker as well
He was referring to running off an H/U.

[micka]

too little power...
http://www.bcae1.com/2ltlpwr.htm

[Blaze]

So for the speakers to run on less power but not fry the voice coil you need to run them off the HU?

[Fhrx]

aka_NSX is right I'm afraid J-MuN. Head unit internal amplifiers can be driven into clipping too, just like their larger external siblings. ;)

[mrwillz]

jmun was that u pumping some splits in jb hi fi day after boxing day...

damn so nice n bass everywhere
hEaDspRunG!~~

[J-MuN]

jmun was that u pumping some splits in jb hi fi day after boxing day...

damn so nice n bass everywhere
hEaDspRunG!~~
lol, yups. We were pretty bored and had no one around so we thought we'd make some noise. :p

[mrwillz]

they were jus splits rite on its own

[J-MuN]

lol not quite. It was the JL Audio VR600's and the twin Kicker 12 Inch subs: DC122 running off the Kicker 04KX600.1 :)

[mrwillz]

oh nice nice

if i run the jvc-ax-as3300 2x65rms for the jvc 6' (cs-fs 6)
will that b sufficient??
also i've never dealt wif small amps, wot gauage cable do i use, and where are small amps usually mounted in a hatch/

[vti-2]

Not enough power to speakers will do more damage than too much power but enough has already been said about it so....

Anyway, regarding RMS output, if you have a PMPO rating you basically divide the PMPO rating by 10 to get an accurate power rating. This is only a 'power' rating. To get the true RMS output you then divide that power rating by 2. So if you have speakers rated at 1000W PMPO, you divide that by 10 to get a 100W power rating. Then divide by 2 to get a 50WRMS rating.

Hope that helps.

[mrwillz]

300 PMPO divide by 10 = 30
true rms 30/2 =15rms for splits....
rite..

[zorrt]

cant convert PMPO to RMS but u can get rough estimate. As vti-2 said, PMPO is generally 5-10 times higher than the RMS but this figure is only an estimate.

[arverson]

ppl ppl, there is NO relation or formula to work out the rms from peak/max/pmpo on SPEAKERS. with SUBS, the rms is generally a 1/3 of max eg. 300rms 900max. but even then, its still a very broad generalisation.

will bro, common places to setup amps (big or small) is under the seats or on the backseat. i say just put it in the back like u have with ur q300. there r advantages/disadvantages to having ur amp/s setup in the boot or under the seats, holla back if u wanna know them =]

as for wats sufficient for speaker wiring, 16 gauge

cya at beach 2day, god DAMN its hot !!

[civicCXI]

Speakers can not be damaged if underpowered. Doesn't really make sense if they did get damaged when a lower power is fed instead of the recommended power.

I disagree, I've seen this happenned. Speakers do get damaged if underpowered. The lower than reccomended power fed into speaker will turn into current and coult burn the speakers.

[mrwillz]

will bro, common places to setup amps (big or small) is under the seats or on the backseat. i say just put it in the back like u have with ur q3000
as for wats sufficient for speaker wiring, 16 gauge
cya at beach 2day, god DAMN its hot !!

yes saw u tehre 2 hrs later

nah wth, sif put in the back, run the wire back thre, then run speaker wire back up lolol. under seat i fink it the place.

thx eleet audio phile lolol.

[mrwillz]

300 PMPO divide by 10 = 30
true rms 30/2 =15rms for splits....
rite..

i was bein sarcastic actually workn it out n gettn 15rms
sounds stupendisly ridiculous... n btw whered chu pull that formula form vti?

[arverson]

nah wth, sif put in the back, run the wire back thre, then run speaker wire back up lolol. under seat i fink it the place.

hahah tru dat, but for ur sake n for others, heres some advantages/disadvantages that come at the top of my head for placing amp under seat/boot:

under seat:
*doesnt take up boot space
*shorter (therefore cheaper) powerwire & RCA cables so there will b less issues with voltage drop
*longer speakerwire: wont cost much more for another 2-3m
*may have less ventilation, not tryna question ur jvc amp but it could have have troubles with venting
*harder to steal
*harder to access tuning controls

boot:
*takes up boot space
*youll have no issues with ventilation - as long as ur jvc amp is a reliable amp :p
*longer powerwires/RCAs; shorter speakerwire
*can make a display out of it
*can get scratched/knocked by items in boot
*easier to access/adjust

edit: woops cable lengths above is for sub wiring, for speaker in the door wiring:
underseat:
*shorter (therefore cheaper) powerwire & RCA cables so there will b less issues with voltage drop
*SHORTER speakerwire

boot: *longer powerwires/RCAs; LONGER speakerwire

[Blaze]

Meh, with all that info we've decided to give it a go and hook the splits to his HU @ 45W, if this screws them up, then that's bad luck from us, at the moment he can't afford another amp or HU so our hands are tied. Tomorrow (Saturday) we are going to fit them in.....hopefully....and I'll tell you how they go.

[arverson]

no probs. most HUs put out about 20rms. but with his HU being a 45w MAX, itll prob b closer to 15rms. plus the fact the rms of those jvc splits r unknown, id b extra careful u, ur friend or any1 dont pump it up too loud as ull push the internal amp in the HU closer to clipping, meaning increasing the chances of yall screwin up ur splits

=]

[vti-2]

i was bein sarcastic actually workn it out n gettn 15rms
sounds stupendisly ridiculous... n btw whered chu pull that formula form vti?

Well, if they were very cheap splits then its realistic that they might have been roughly 20wrms per channel.

Anyway, the formula is something i've heard a few audio guys tell me about before. Nothing i made up myself. I've never really had to use it because i've always bought top quality products that dont try to cover up their speakers true power rating. All speakers i've bought had an RMS rating.

Anyway, dont take that formula as the one and only. As i said its something i picked up from a few car audio nuts that have used it as a 'general rule of thumb'. :)

[Blaze]

Just installed the speakers, they aren't bad, but they don't go as loud as we want them too. oh well till we get a new HU or amp my mate is stuck with them.

[arverson]

vti: i know ur just tryna help ppl out BUT told by car audio nuts or not, i still wouldnt use that formula. y?? cus lower end car audio brands like jvc, kenwood, sony & pioneer (no offence to ppl who have them :P) make up/skew most of their max/peak/pmpo ratings to lure in ppl who are new to car audio. thus NO formula will work.

like urself, id also only buy speakers that show their rms ratings but mrwillz is alredy gettin the splits+amp cheap & blazes friend alredy has em so its best to give em more accurate info. by that i mean i dont want ppl using that formula as it simply doesnt work :)


blaze: if ur friend wants his music louder, then a new HU wont solve that. all speakers sound better off an amp. theres a good reason why amps are bigger than a HU, even tho a HU is expected to have sufficient grunt to run the speakers

without gettin tooo technical, a amp will provide:
. more power = more volume
. more grunt = better bass and clarity, dynamics, etc
. better sound quality & clarity
. inbuilt xover filters: removes the subbass from the signal, therefore leaving the speakers do wat they do best (play only the mids & highs[treble]). speakers arnt designed to play the lows(subbass) loudly as it causes early distortion and adversely affects clarity

i dunno wat ur friend had b4 those jvc splits but if ur friend can compromise on not being able to play his music LOOUUD and is happy with the result then all good. but if not, then when ur friend CAN afford the amp, get one. the benefits will b obvious :)

[Blaze]

Aversion, my mate had stocks in before the JVC's. He's a beginner when it comes to car modding and he is blind (and deaf) when it comes to his posessions. When he first told me about his "system" (stock speakers, aftermarket HU, amp and sub) he made it sound like he had the best system on the planet, and that's the way he describes his "system" to everyone even tho it's all stock except for the HU, amp and sub. So when it comes down to weather he likes the upgrade or not, I think he's already telling everyone that he has "competition speakers" in his car lol. Oh well, he's a good kid but he hasn't got much money to throw around and he would rather settle for the temporary than waiting and getting the job done properly a bit later.

[vti-2]

vti: i know ur just tryna help ppl out BUT told by car audio nuts or not, i still wouldnt use that formula. y?? cus lower end car audio brands like jvc, kenwood, sony & pioneer (no offence to ppl who have them :P) make up/skew most of their max/peak/pmpo ratings to lure in ppl who are new to car audio. thus NO formula will work.

like urself, id also only buy speakers that show their rms ratings but mrwillz is alredy gettin the splits+amp cheap & blazes friend alredy has em so its best to give em more accurate info. by that i mean i dont want ppl using that formula as it simply doesnt work :)

You for real? There is no way a company like Sony or Pioneer would make up or 'skew' their speaker ratings just to sell their product. That is total crap. If anything, they use PMPO or 'peak' ratings so that the speakers appear to have a higher rating than other products. You shouldn't just assume that they make up their ratings as you don't know this as a matter of fact. Are you aware there are lawsuits that exist that could be used against you for implying what you said above? Have a nice day. :)


Having said that i'd be interested to know exactly how you would work out the RMS rating from a PMPO rated speaker.

[vividjazz]

You can't work out RMS from PMPO because they all seem to use different methods to calculate PMPO. They might as well just use ILS (if lightning strikes) cause thats the only way they'll reach those numbers before they disintegrate.

[Blaze]

vti-2, averson has a point, when you look at some of the speakers that companies offer, I'll use pioneer as an example, it does look a bit suspect when you compare the rms ratings of their high end models compared to the lower priced ones aimed at people who buy with their eyes and not their ears.

EG:
Pioneer's TS-A6991S model 6x9's have an RMS rating of 80W and a Max rating of 460W

The High end 6x9's on the other hand have an RMS of 80W and a max figure of 350W

Both rms and max ratings are stated on both models but despite having an equal RMS value their max rating is different, with the high end model having a lower max rating...it does look like they have just pulled the 460W out of thin air and slapped it onto a speaker so it will sell.

[arverson]

blaze: wasnt implying that he HAS to get a amp or make it his #1 priority, just advising that IF in the future he wants more volume that a amp provides(plus the other benefits), then a amp would be the way to go instead of a HU

vti: yes, brands do use and advertise their max/peak/pmpo to take advantage of noobs and cus of that, they do over-rate these specs on some speakers. i do realise i probably shouldnt have named specific brands but if thats what it takes to better educate, advise & help the general public, then so be it.

how do i work out the RMS rating from a PMPO rated speaker? i dont. cus as ive said, theres no relation or formula thats works. i look for the rms only, i take no consideration about the max/peak rating when buying anything car audio related. if the speaker doesnt show a rms/nominal/continuos rating, then i wouldnt buy it.

the point of that post was meant to b more focused on how that specific formula doesnt work. im not trying to start u vti, im just friendly trying to point out that that formula doesnt work. go check out some speakers, use that specific formula and see if u get the rms stated. till u do, ill stand corrected. but even after u showed me which speakers the formula worked on, i still wouldnt use it :)

[arverson]

woops blaze, my post above^ was in reply to ur previous post, but thanks for backing me up =]

[Blaze]

No worries, I think the amp is next to be improved but I'm not sure.

[Blaze]

Ok fair enough, this thread was originally started so I could find out a power rating, but I also e-mailed JVC, and they just sent me a reply. You guys are not going to beleive the RMS rating on these speakers.
This is the reply I got:

"Hi and thank you for e-mailing JVC Australia.

The RMS rating on the CS-FS6 is 100W RMS.

Regards"

Now I don't know much about this stuff, but that is a pretty high number considering all other speakers who's ratings are around 40-70 (majority of speakers). Your thoughts?

[Slow96GSR]

It's all relative to the coil and the size. 100 watts is low in comparison to some of the speakers I've used and high to some others.

[Blaze]

Do you think it's an accurate RMS rating then? cuz we are powering them thru the HU and they are being seriously underpowered if they are 100W.

[arverson]

theres plenty of speakers that have the same/higher rms's WITH lower max ratings - focal 165k2p, morel pulse 6, hertz hsk165 to name a few examples - so i wouldnt get caught up worrying if those jvc splits r actually 100rms or not. jvc said so themselves so dont doubt em and definately dont ask urself 'ohh they r 300max, 100rms cant b rite'

in a sense there no such thing as 'seriously' underpowered & 'a little bit' underpowered.
u underpower speakers off a HU but u also underpower ur speakers when u turn it down. as long as u dont push the HUs internal amp to do more than it can handle (ask for more volume than the 15ish rms watts ur frendz 45@4 HU can handle), ur frendz spits will b fine.