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Amp specs for Alpine Premium System?

enrico_pallazzo

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I was curious if anyone has the specs of the amp that comes with the Alpine Premium system. I'm looking at speaker swaps and want to make sure I don't go overboard with speakers resulting in the amp being underpowered. Thanks.
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YayMud!

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I am surprised no one responded to your thread. In case you are still looking for answers, just about any aftermarket speaker will be underpowered with the factory Alpine amp because the amp is at 2 ohms and most speakers are at 4 ohms. The factory amp supposedly sends 46W peak per channel or 23W RMS, but at 2 ohms this is just over 10W RMS to a 4 ohm speaker.
 
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enrico_pallazzo

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Thanks for sharing these details! I hadn’t been able to find specs, but this is more or less what I worried about. So disappointing that an expensive system has such garbage specs. I’m not expecting some nutso competition amp power or anything, just something that can reasonably power good speakers. If I get another JT, I’m going to get the stock audio and go aftermarket.
 

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No wonder the premium system seems wimpy to me - I was running 2 amps each rated at over 200 watts into 10 speakers in my little Comanche cab.
This system just isn't crisp and clear and isn't capable of reproducing the sound I got out of my old system.
What's up with those speaker impedance numbers?
My VERY LIMITED understanding is that speakers with lower impedances are harder to drive and require more powerful amplifiers. And yet the system in these uses 2ohm speakers with the limited amp.
 

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Ironically, it's almost easier to go aftermarket with the Alpine system because of how many companies are supporting factory integration/bypass now. Literally a plug and play solution - if you really want to go that far.

I'm going that route in our 20 JT, but will probably mess around with the factory setup first.

These are some SB Acoustics SB12NRX25-4 I have laying around in the speaker stash. Thinking they might work to replace the factory 4", but still looking for a suitable alternative to the 3.5"

Jeep Gladiator Amp specs for Alpine Premium System? 51312352712_315d1bb75a_c


Jeep Gladiator Amp specs for Alpine Premium System? 51314101090_ea2fa263dc_c


They are just barely too big for the 4" spot, would take a minor amount of trimming to make them fit:

Jeep Gladiator Amp specs for Alpine Premium System? 51313095226_5512230511_c
 

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YayMud!

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Ironically, it's almost easier to go aftermarket with the Alpine system because of how many companies are supporting factory integration/bypass now. Literally a plug and play solution - if you really want to go that far.

I'm going that route in our 20 JT, but will probably mess around with the factory setup first.

These are some SB Acoustics SB12NRX25-4 I have laying around in the speaker stash. Thinking they might work to replace the factory 4", but still looking for a suitable alternative to the 3.5"

Jeep Gladiator Amp specs for Alpine Premium System? 51313095226_5512230511_c


Jeep Gladiator Amp specs for Alpine Premium System? 51313095226_5512230511_c


They are just barely too big for the 4" spot, would take a minor amount of trimming to make them fit:

Jeep Gladiator Amp specs for Alpine Premium System? 51313095226_5512230511_c
Those look like a lot better quality than the factory speakers. Now you will just need a different amp to power them since I am sure your new speakers are 4 ohms instead of the factory 2 ohm.
 

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Most amplifiers are current limited so if the amp can drive a 2 ohm speaker to some amount of power with a certain THD it will not be exactly half that into 4 ohms. It also depends on what peak voltage the amplifier can produce at rated THD. If you look at typical amplifier specs the difference in power going from a 4 ohm load to a 2 ohm load is typically close to 70%, so a 46w amp into 2 ohms would be about 32 watts into 4 ohms. This also doesn't mean the replacement 4 ohm speakers will be 70% as loud, that depends on speaker efficiency and a few other things.

To add more confusion, the 3 1/2" speakers I removed from my Mojave with premium sound system were 4 ohm speakers and the Kenwood replacements were 4 ohms speakers, so apples to apples. Where does the 2 ohm spec come from that I see mentioned here and there? Is that a speaker or amplifier spec?

Peak power vs RMS power in amplifier ratings is not calculating peak voltage by .707 to get RMS voltage. RMS specs in an amplifier usually means what the amplifier is capable of producing continuously. Peak amplifier power is what the amplifier can do in short bursts and the difference between amplifier RMS and peak is its headroom usually specified in dB.

I am surprised no one responded to your thread. In case you are still looking for answers, just about any aftermarket speaker will be underpowered with the factory Alpine amp because the amp is at 2 ohms and most speakers are at 4 ohms. The factory amp supposedly sends 46W peak per channel or 23W RMS, but at 2 ohms this is just over 10W RMS to a 4 ohm speaker.
 

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Most amplifiers are current limited so if the amp can drive a 2 ohm speaker to some amount of power with a certain THD it will not be exactly half that into 4 ohms. It also depends on what peak voltage the amplifier can produce at rated THD. If you look at typical amplifier specs the difference in power going from a 4 ohm load to a 2 ohm load is typically close to 70%, so a 46w amp into 2 ohms would be about 32 watts into 4 ohms. This also doesn't mean the replacement 4 ohm speakers will be 70% as loud, that depends on speaker efficiency and a few other things.

To add more confusion, the 3 1/2" speakers I removed from my Mojave with premium sound system were 4 ohm speakers and the Kenwood replacements were 4 ohms speakers, so apples to apples. Where does the 2 ohm spec come from that I see mentioned here and there? Is that a speaker or amplifier spec?

Peak power vs RMS power in amplifier ratings is not calculating peak voltage by .707 to get RMS voltage. RMS specs in an amplifier usually means what the amplifier is capable of producing continuously. Peak amplifier power is what the amplifier can do in short bursts and the difference between amplifier RMS and peak is its headroom usually specified in dB.
There is definitely some variance in amp output quality between 2 ohm and 4 ohm. They can range anywhere from 50% up to close to 70% difference in power at the different ohm settings. Impossible to know for sure unless you have the exact power outputs from the manufacturer.

Everything I read about our Alpine system is that everything is at 2 ohms.

RMS is what I always look at in amp and speaker ratings as it is more reliable and constant vs. peak, like you mentioned earlier. Peak is typically at least double the RMS rating for most good speakers. Again, there is a lot of variance here as well depending on the construction of the speaker.

The 46W/channel peak rating for the Alpine amp in our system means that 23W at 2 ohms would be an extremely generous rating. Even if it still carried 70% of that power to a 4 ohm speaker that would be 16W/channel, not 32W/channel. This is why my Rockford component speakers that can handle 40W RMS and 80W peak at 4 ohms are starving with a 2 ohm amp that only provides 46W peak at 2 ohms.
 

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This is from the JL forum but should help

Jeep Gladiator Amp specs for Alpine Premium System? 4E05D4B3-FB1B-4D54-BE98-7B38539EF5B7
 

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I only tested the 3 1/2" speakers taken out of my dash and sound bar and they were single cone speakers with voice coil DC resistance right at 4 ohms. It could be other size speakers in the system could be 2 ohms but that would be an odd thing to do for a factory system. In my opinion a 2 ohm speaker setup is to be avoided in a vehicle environment which is not typical for car stereo amplifiers and it requires larger guage speaker wire as the lower impedance you go on speakers, the more sensitive the system becomes with speaker wire resistance. In a home stereo its easy to upgrade to huge speaker wire for 2 ohm speakers but vehicle mfrs want to cut costs like avoiding more expensive speaker wire.

If the stereo amplifier is rated to drive a 2 ohm load that's very good but it doesn't matter much if you connect a 4 or 8 ohm speaker to it. It just means it has a higher than normal current driving capability for the lower impedance speakers.

I remember my stereo installer days in the mid 70s to early 80s where I would always upgrade the speaker wire supplied by the aftermarket speaker mfrs. Take an old 4 ohm Jensen 6 X 9 with mid and tweet and go from the supplied 20 or 22ga wire to 12 ga and it was like hitting the "loudness" button on the old stereos which boosted the bass. The loss in even a short run of 22ga speaker wire is very audible on a 4 ohm car speaker and a 2 ohm would be worse.

There is definitely some variance in amp output quality between 2 ohm and 4 ohm. They can range anywhere from 50% up to close to 70% difference in power at the different ohm settings. Impossible to know for sure unless you have the exact power outputs from the manufacturer.

Everything I read about our Alpine system is that everything is at 2 ohms.

RMS is what I always look at in amp and speaker ratings as it is more reliable and constant vs. peak, like you mentioned earlier. Peak is typically at least double the RMS rating for most good speakers. Again, there is a lot of variance here as well depending on the construction of the speaker.

The 46W/channel peak rating for the Alpine amp in our system means that 23W at 2 ohms would be an extremely generous rating. Even if it still carried 70% of that power to a 4 ohm speaker that would be 16W/channel, not 32W/channel. This is why my Rockford component speakers that can handle 40W RMS and 80W peak at 4 ohms are starving with a 2 ohm amp that only provides 46W peak at 2 ohms.
 

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I thought the speaker "ohm" rating was impedance - resistance to AC current......... would that not be different than the measure of resistance using a VOM and DC current?
 

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Yes it is, impedance is an AC measurement where ohms measured with a ohmmeter are a DC measurement. However since speaker impedance is very low with minimal inductance in the voice coil, the impedance measurement will be very close to the DC resistance. Bottom line is a DC ohm measurement will usually pin down the impedance rating of most speakers.

The place where this may get skewed is a two way system with a simple capacitor 3dB/octave crossover where at DC you will read the pure woofer voice coil resistance and the tweeter is out of circuit but near the crossover frequency you will have the AC impedance of the woofer and the AC impedance of the tweet in parallel pulling the impedance down to maybe half of what the woofer might be. The impedance curve on this type of speaker can vary all over the place.

I thought the speaker "ohm" rating was impedance - resistance to AC current......... would that not be different than the measure of resistance using a VOM and DC current?
 

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Yes it is, impedance is an AC measurement where ohms measured with a ohmmeter are a DC measurement. However since speaker impedance is very low with minimal inductance in the voice coil, the impedance measurement will be very close to the DC resistance. Bottom line is a DC ohm measurement will usually pin down the impedance rating of most speakers.

The place where this may get skewed is a two way system with a simple capacitor 3dB/octave crossover where at DC you will read the pure woofer voice coil resistance and the tweeter is out of circuit but near the crossover frequency you will have the AC impedance of the woofer and the AC impedance of the tweet in parallel pulling the impedance down to maybe half of what the woofer might be. The impedance curve on this type of speaker can vary all over the place.
Makes sense as I can remember as a kid measuring speakers with my Micronta meter and then later learning about the difference and wondering..........
 

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I’ve said it before…


Here's some interesting reading...
https://en.wikipedia.org/wiki/Sound_pressure
Look at the Examples of Sound Pressure table in particular. You'll note that hearing damage will begin to occur at 85dB.
Even low quality speakers will produce close to 85dB with only 1 watt of power.
Also worth mentioning, a 3dB level change is barely noticeable, and 5dB is noticeable. To double the loudness, you need a 10dB increase, which is a 10 times increase in power.
Bottom line: a change from 23W to 40W will be a barely noticeable increase in loudness.

Kevin
 

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I’ve said it before…


Here's some interesting reading...
https://en.wikipedia.org/wiki/Sound_pressure
Look at the Examples of Sound Pressure table in particular. You'll note that hearing damage will begin to occur at 85dB.
Even low quality speakers will produce close to 85dB with only 1 watt of power.
Also worth mentioning, a 3dB level change is barely noticeable, and 5dB is noticeable. To double the loudness, you need a 10dB increase, which is a 10 times increase in power.
Bottom line: a change from 23W to 40W will be a barely noticeable increase in loudness.

Kevin
I did mine how I did for sound clarity. Wasn't necessarily for how "loud" I could get it (that was an end result and it turned out so good I was talked into entering contests by the shop I bought the stuff from). I heard sounds in my music I had not heard before. I already had high frequency hearing loss to some extent by then but still - I could hear some of the background instruments and vocals I'd not really heard like that before. I had to have some real "power" and really good speakers to get to that point.
I also had the Alpine CD that had a mix of music on it that demonstrated more clearly how things sounded with good clean power.
So for me, it started out wanting to hear the music as it was intended to be heard, and hear ALL of it - hey, I didn't know there was sitar in that piece, sort of thing.

With that system, you didn't have to have the windows shaking to hear the music, ALL of it, well.
But if you wanted that outdoor concert sound, you had that as well. It was more like the band was right there.

That's what I'd like out of this truck - true quality sound reproduction, to hear those vocals or instruments you don't normally get to hear in just "so-so" systems.
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