2ohm speakers to new alpine cda-9857 4ohm head unit

[[email protected]]

Hello,

I have recently replaced my stock head unit with an Alpine CDA-9857. I
would like to replace my four speakers that are currently 6x8/4ohm with
Infinity Kappa's that are 6x8 but 2ohm. I talked to Crutchfield and
they said it won't be a problem just as long as I don't run the amp
really loud for extended periods of time (which I never do..) when I
talked to Alpine they said that I should not replace the current
speakers with 2ohm. I understand that running a 2ohm load will pull
more power from the amp and make it run hotter, my question is how
dangerous is this? From user reviews on the net, the Kappa's will sound
great but if they will damage my system I'd of course rather go with a
safer 4ohm load...

thanks in advance,
Kedar Roy

[MOSFET]

Geez, that's a REALLY GOOD question. I was curious about why anyone would
sell a 2 ohm 6x8 coaxial so I went to Infinity's site and SURE ENOUGH, there
it is. Infinity says that this 2 ohm resistance level produces more power.
From their site:

"Conventional 4-ohm speakers do not leverage all of the power available
from today's car audio amplifiers and high-powered head units. This topology
extracts every last watt from the amplifier source, increasing overall
system output and efficiency. "

Note the "high-powered head units" part. Obviously, Infinity MUST have had
HU in mind when they designed these speakers. Therefore, I would tend to
take the advice that driving these with a HU is OK, just don't blast the
hell out them for extended periods of time. Also, it would be best if you
were using these in conjunction with a subwoofer, this way you could limit
the bass going to the Infinity's (a simple capacitor would give you a 6 dB
per octave passive high-pass X-over) as bass consumes MUCH more power than
treble and is where you would most likely run into trouble with your HU
overheating.

Perhaps Infinity has a Q/A page, FAQ or even a phone number where you can
call and ask them directly. Again, my guess would be that it would be OK as
long as you don't punish them.

MOSFET

> wrote in message
ups.com...
> Hello,
>
> I have recently replaced my stock head unit with an Alpine CDA-9857. I
> would like to replace my four speakers that are currently 6x8/4ohm with
> Infinity Kappa's that are 6x8 but 2ohm. I talked to Crutchfield and
> they said it won't be a problem just as long as I don't run the amp
> really loud for extended periods of time (which I never do..) when I
> talked to Alpine they said that I should not replace the current
> speakers with 2ohm. I understand that running a 2ohm load will pull
> more power from the amp and make it run hotter, my question is how
> dangerous is this? From user reviews on the net, the Kappa's will sound
> great but if they will damage my system I'd of course rather go with a
> safer 4ohm load...
>
> thanks in advance,
> Kedar Roy
>

[KU40]

I wouldn't do it. if you fry the amp inside the head unit you'll
basically have to get a new one, and the warranty may not cover it
since it's being run out of spec. and those aren't too cheap. Those
speakers are pretty much made to be run off an amp since they made them
2 ohm and pretty much every amplifier is at least 2 ohm stable in
stereo.


--
KU40

[Captain Howdy]

I agree, running your hu at a 2ohm load is just nutz.


In article >, KU40
> wrote:
>
>I wouldn't do it. if you fry the amp inside the head unit you'll
>basically have to get a new one, and the warranty may not cover it
>since it's being run out of spec. and those aren't too cheap. Those
>speakers are pretty much made to be run off an amp since they made them
>2 ohm and pretty much every amplifier is at least 2 ohm stable in
>stereo.
>
>

[MOSFET]

>I agree, running your hu at a 2ohm load is just nutz.
>
I know Howdy, but why would Infinity sell a set of coaxials they know would
fry every HU they were connected to? I mean, people who buy coaxials
FREQUENTLY buy them SIMPLY as replacements for stock speakers (the only
change they make to their stock system is they change out the speakers).
Would Infinity REALLY be so stupid as to sell a set of speakers that would
SURELY DESTROY every stock HU they were connected to?

I suspect (and this is JUST a hunch), that this has more to do with
marketing than actual ohm ratings. YOU KNOW how data can be manipulated.
Perhaps THEY ARE 2 ohms at ONE CERTAIN FREQUENCY, but not at 1kHz as most
speakers are rated. This is JUST a guess, but I'll bet their true
resistance is likely around 3 ohms.

Again, it would be shooting yourself in the foot to sell speakers that
destroy HU's. BUT, marketers (remember, I have an MBA with an emphasis in
marketing) are not above manipulating figures in order to try and gain an
advantage ON PAPER, OR PROMOTIONAL MATERIAL, OR AS PART OF A SALES PITCH.
But I trust that the engineers at Infinity have a little more sense than
their marketing counterparts.

Just my $.02,

MOSFET

[MOSFET]

Yes, but my point is that I SUSPECT (and this is just a guess) that this 2
ohm rating is an exaggeration. By claiming 2 ohms, they will make consumers
think their coaxial will be louder.

But again, INFINITY would be stupid to sell something that would cause
problems and damage other components. It's simply not good business.

Now I could be wrong, but I'll bet you that this 2 ohm rating is a stretch
(why else would they say on their web-site that THEY CAN be used with
high-power HU's?). I think it's a marketing ploy, Infinity has been around
a long time and they just CAN'T be THIS stupid (by making a speakers that
will fry a user's HU). People would be SO MAD, they would never buy a piece
of Infinity gear again.

And Howdy, when was the last time you could REALLY trust the specifications
given by ANY consumer electronics manufacturer?

MOSFET

"Captain Howdy" > wrote in message
...
> It's just so people can get max power out of their external amplifiers.
> Hooking them up to a hu doesn't mean that you would get smoke and flames
> right
> away, but it will sure bring on early failure. Hu are just not made to
> deal
> with that kind of heat that this will bring, and even if the chip was to
> hold
> it's own the laser would not be too happy with the extra heat. Some Hu's
> run
> as hot as hell at rated specs.
>
> Most people have their gear professionally installed and most often the
> people
> that install their own gear get no factory warranties anyways. Most off
> all
> what does Infinity care if you fry your HU. No one is going to fry any
> Infinity HU's, and that's without a doubt LOL.
>
>
> In article >, "MOSFET"
> > wrote:
>>>I agree, running your hu at a 2ohm load is just nutz.
>>>
>>I know Howdy, but why would Infinity sell a set of coaxials they know
>>would
>>fry every HU they were connected to? I mean, people who buy coaxials
>>FREQUENTLY buy them SIMPLY as replacements for stock speakers (the only
>>change they make to their stock system is they change out the speakers).
>>Would Infinity REALLY be so stupid as to sell a set of speakers that would
>>SURELY DESTROY every stock HU they were connected to?
>>
>>I suspect (and this is JUST a hunch), that this has more to do with
>>marketing than actual ohm ratings. YOU KNOW how data can be manipulated.
>>Perhaps THEY ARE 2 ohms at ONE CERTAIN FREQUENCY, but not at 1kHz as most
>>speakers are rated. This is JUST a guess, but I'll bet their true
>>resistance is likely around 3 ohms.
>>
>>Again, it would be shooting yourself in the foot to sell speakers that
>>destroy HU's. BUT, marketers (remember, I have an MBA with an emphasis in
>>marketing) are not above manipulating figures in order to try and gain an
>>advantage ON PAPER, OR PROMOTIONAL MATERIAL, OR AS PART OF A SALES PITCH.
>>But I trust that the engineers at Infinity have a little more sense than
>>their marketing counterparts.
>>
>>Just my $.02,
>>
>>MOSFET
>>
>>
>>

[[email protected]]

I'll be recieving the speakers shortly - I'll put them on my multimeter
and see what it says and post the results...either way I think I'm
going to get an amp installed anyways...

thanks again,
-Kedar

MOSFET wrote:
> Yes, but my point is that I SUSPECT (and this is just a guess) that this 2
> ohm rating is an exaggeration. By claiming 2 ohms, they will make consumers
> think their coaxial will be louder.
>
> But again, INFINITY would be stupid to sell something that would cause
> problems and damage other components. It's simply not good business.
>
> Now I could be wrong, but I'll bet you that this 2 ohm rating is a stretch
> (why else would they say on their web-site that THEY CAN be used with
> high-power HU's?). I think it's a marketing ploy, Infinity has been around
> a long time and they just CAN'T be THIS stupid (by making a speakers that
> will fry a user's HU). People would be SO MAD, they would never buy a piece
> of Infinity gear again.
>
> And Howdy, when was the last time you could REALLY trust the specifications
> given by ANY consumer electronics manufacturer?
>
> MOSFET
>
> "Captain Howdy" > wrote in message
> ...
> > It's just so people can get max power out of their external amplifiers.
> > Hooking them up to a hu doesn't mean that you would get smoke and flames
> > right
> > away, but it will sure bring on early failure. Hu are just not made to
> > deal
> > with that kind of heat that this will bring, and even if the chip was to
> > hold
> > it's own the laser would not be too happy with the extra heat. Some Hu's
> > run
> > as hot as hell at rated specs.
> >
> > Most people have their gear professionally installed and most often the
> > people
> > that install their own gear get no factory warranties anyways. Most off
> > all
> > what does Infinity care if you fry your HU. No one is going to fry any
> > Infinity HU's, and that's without a doubt LOL.
> >
> >
> > In article >, "MOSFET"
> > > wrote:
> >>>I agree, running your hu at a 2ohm load is just nutz.
> >>>
> >>I know Howdy, but why would Infinity sell a set of coaxials they know
> >>would
> >>fry every HU they were connected to? I mean, people who buy coaxials
> >>FREQUENTLY buy them SIMPLY as replacements for stock speakers (the only
> >>change they make to their stock system is they change out the speakers).
> >>Would Infinity REALLY be so stupid as to sell a set of speakers that would
> >>SURELY DESTROY every stock HU they were connected to?
> >>
> >>I suspect (and this is JUST a hunch), that this has more to do with
> >>marketing than actual ohm ratings. YOU KNOW how data can be manipulated.
> >>Perhaps THEY ARE 2 ohms at ONE CERTAIN FREQUENCY, but not at 1kHz as most
> >>speakers are rated. This is JUST a guess, but I'll bet their true
> >>resistance is likely around 3 ohms.
> >>
> >>Again, it would be shooting yourself in the foot to sell speakers that
> >>destroy HU's. BUT, marketers (remember, I have an MBA with an emphasis in
> >>marketing) are not above manipulating figures in order to try and gain an
> >>advantage ON PAPER, OR PROMOTIONAL MATERIAL, OR AS PART OF A SALES PITCH.
> >>But I trust that the engineers at Infinity have a little more sense than
> >>their marketing counterparts.
> >>
> >>Just my $.02,
> >>
> >>MOSFET
> >>
> >>
> >>

[MOSFET]

> I'll be recieving the speakers shortly - I'll put them on my multimeter
> and see what it says and post the results...either way I think I'm
> going to get an amp installed anyways...

That's a VERY good idea to get the amp, just to be sure, AND it will surely
sound MUCH better than HU power.

As far as the multimeter test on the speakers, this will not yield any
useful information as resistance changes with frequency (when feeding the
speaker a 1kHz tone, it may exhibit 4 ohms of resistance, however at 20 kHz,
the resistance will likely be very different). Just now, I put my
multimeter on my home speakers that are rated at 8 ohms and got a reading of
6.5 ohms. However, this DOES NOT mean my speakers really have a 6.5 ohm
resistance.

MOSFET

[[email protected]]

Oh...ok..nevermind then :)

I'll keep them aside till I get an amp installed

thanks again,
Kedar

MOSFET wrote:
> As far as the multimeter test on the speakers, this will not yield any
> useful information as resistance changes with frequency (when feeding the
> speaker a 1kHz tone, it may exhibit 4 ohms of resistance, however at 20 kHz,
> the resistance will likely be very different). Just now, I put my
> multimeter on my home speakers that are rated at 8 ohms and got a reading of
> 6.5 ohms. However, this DOES NOT mean my speakers really have a 6.5 ohm
> resistance.
>
> MOSFET

[KU40]

you still can check the impedence with the dmm while the speaker is
playing to see what impedences it shows at different frequencies. just
play some test tones to keep the frequency steady and the dmm will show
the resistance at that frequency.


--
KU40

[KU40]

you still can check the impedence with the dmm while the speaker is
playing to see what impedences it shows at different frequencies. just
play some test tones to keep the frequency steady and the dmm will show
the resistance at that frequency.


--
KU40

[Vivek]

Just a step away from the topic. Are these speakers too good to worry about
the impedence. Why not buy another rated at 4ohm.

> wrote in message
ups.com...
| Hello,
|
| I have recently replaced my stock head unit with an Alpine CDA-9857. I
| would like to replace my four speakers that are currently 6x8/4ohm with
| Infinity Kappa's that are 6x8 but 2ohm. I talked to Crutchfield and
| they said it won't be a problem just as long as I don't run the amp
| really loud for extended periods of time (which I never do..) when I
| talked to Alpine they said that I should not replace the current
| speakers with 2ohm. I understand that running a 2ohm load will pull
| more power from the amp and make it run hotter, my question is how
| dangerous is this? From user reviews on the net, the Kappa's will sound
| great but if they will damage my system I'd of course rather go with a
| safer 4ohm load...
|
| thanks in advance,
| Kedar Roy
|

[Chad Wahls]

No it won't, it will simply **** off the meter. In R mode the meter looks
at a voltage drop over a known resistance, the meter supplies the voltage
sounce. Inserting AC voltage into the equation will **** the meter off,
ruin it, or blow the protection fusing if it has any.

Resistance is a DC measurement. Impedance is an AC measurement. To do
impedance measurement you will need to put a resistor in SERIES with the
speaker and measure voltage drop from there in V MODE while playing test
tones or preferably a sweep while doing a plot. Calculate then derive a
nominal impedance.

DCR is NOT impedance. DO NOT attach an Ohmmeter to the speaker terminals
while an apmlifier is operational. If it is not operational you will get
damn near a dead short reading due to the VERY LOW output impedance of solid
state designs.

Chad

"KU40" > wrote in message
...
>
> you still can check the impedence with the dmm while the speaker is
> playing to see what impedences it shows at different frequencies. just
> play some test tones to keep the frequency steady and the dmm will show
> the resistance at that frequency.
>
>
> --
> KU40

[[email protected]]

Actually, I don't know if they are too good, but I do know they are
"too purchased"! I got a really good deal on them and did'nt know about
this imedance wierdness till later...besides it gives me an excuse to
get an amp for the car...


Vivek wrote:
> Just a step away from the topic. Are these speakers too good to worry about
> the impedence. Why not buy another rated at 4ohm.
>
>

[Vivek]

|...besides it gives me an excuse to get an amp for the car...

9857 is a nice set. Just don't ignore this excuse! Anyway you will buy an
amp sooner or later :)