Amp peak power twice RMS power?
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=49772
Printed Date: May 09, 2024 at 10:56 PM
Topic: Amp peak power twice RMS power?
Posted By: boardinbum
Subject: Amp peak power twice RMS power?
Date Posted: February 10, 2005 at 1:50 AM
I'm looking at a Profile amp ( here), and I can't find the actual peak power @ 4-ohms anywhere. All I can find is that it's RMS power @4ohms is 480x1. So should I assume its peak power is about 900 watts-ish?
Replies:
Posted By: ty
Date Posted: February 10, 2005 at 2:02 AM
don't really worry about peak power, when looking for an amp + speaker combo always look at the rms power, but to answer your question it probably is around 900 watts peak, but remember that is at 14.4 volts, you will see probably less watts if your alternator/battery/wiring is not up to par.
Posted By: boardinbum
Date Posted: February 10, 2005 at 2:10 AM
Why do you say that's at 14.4 volts?
Posted By: richiec77
Date Posted: February 10, 2005 at 3:01 AM
No. Peak is just peak. Really doesen't matter. RMS is 0.707 or 70% of the wave. That is the industry standard for the average workload output. So 700 RMS would be 1000 Peak. Not 2x RMS.
Posted By: boardinbum
Date Posted: February 10, 2005 at 3:10 AM
So if I'm looking at a sub ( Kicker L5), and the rms is 450, and peak is 900, I should be okay with a 480 rms amp, right?
Posted By: kfr01
Date Posted: February 10, 2005 at 3:41 AM
Yep. Don't even look at peak for subwoofers. Only RMS for both drivers and amplifiers.
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New Project: 2003 Pathfinder
Posted By: boardinbum
Date Posted: February 10, 2005 at 3:50 AM
Alright. Thanks for the help.
One last question...
I'm putting one 10" in my new little reg. cab Tacoma.
Looking to put roughly 300watts rms in it, but not spend over $200-ish for sub and amp (probably end up buying them off of eBay).
As of now, I'm looking at getting either this Kicker CVR102 or this Alpine Type R.
And they'll probably be powered by this Profile amp.
Any suggestions on which sub to go with? Or suggestions on a different sub that'll run about ~$100 (eBay) and take about 300watts?
Posted By: kfr01
Date Posted: February 10, 2005 at 4:04 AM
I'd buy that Alpine over the kicker any day.
If I was on that kind of budget I'd buy a $70 Dayton subwoofer from partsexpress here: https://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=295-555
Then buy a better brand amplifier than profile.
https://cgi.ebay.com/dll?ViewItem&category=18797&item=5750430193&tc=photo
I am confident this would provide better sound than the previous system.
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New Project: 2003 Pathfinder
Posted By: boardinbum
Date Posted: February 10, 2005 at 4:07 AM
That amp is 150x1rms, and it's $170 with shipping.
I can get a 310x1 Profile for $115 or less shipped.
and I'm going to build a sealed box, but I figured that'll cost me like $20 or less.
Posted By: boardinbum
Date Posted: February 10, 2005 at 4:20 AM
Also, when it says "Bridged Power Output at 14.4V (1kHz, 0.8% THD): 460 Watts x 1"
What happens when you run it at 12v? Or can you run them at 12v?
Posted By: boardinbum
Date Posted: February 10, 2005 at 4:30 AM
...And one last question... I could buy the
Alpine SWR-1241D which has a dual 4-ohm voice coil and just wire it in parallel for a 4-ohm load, right?
(I ask because eBay doesn't seem to have any dual 2-ohm voice coil Type R 12's right now. And I plan to wire my sub at 4ohms)
Posted By: kfr01
Date Posted: February 10, 2005 at 5:02 AM
They simply put out less power at 12v.
I wouldn't put too much stock in the power ratings Profile lists. The Memphis amp is probably just as powerful as that profile and is undoubtedly cleaner. There's a reason the "300w" profile is cheaper - it isn't a good amp. Also, you must learn that the MAX SPL difference between a full 150w and 300w is only 3db. 3db is small.
1) Why are you bent on wiring your sub at 4-ohms?
2) dvc 4-ohm cannot be wired to 4 ohms... 2 or 8 only. I wouldn't try one.
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New Project: 2003 Pathfinder
Posted By: boardinbum
Date Posted: February 10, 2005 at 9:41 AM
It's not that I'm bent on wiring it at 4-ohms, it's that the Type R that I can get cheap on eBay is dual 4-ohm. So how would you recommend wiring that?
Posted By: matttx
Date Posted: February 10, 2005 at 10:23 AM
Wiring Option #1
 Wiring Option #2
 These are your options. Yet another reason you do not want that Profile amp. It is not stable at 2 ohms bridged. The memphis will give 250 w rms using option #1.
Posted By: pimpincavy
Date Posted: February 10, 2005 at 11:41 AM
How cheap is the type R on ebay? Its $95 on Ikesound.com
I have that Memphis amp, its definatly a powerful amp, I had it driving 2 subs and it worked great. Im not using it anymore b/c I bought a JBL 600.1, but the amp is for sale, PM me if you are interested. Its like new, only used for a few months. -------------
Posted By: boardinbum
Date Posted: February 10, 2005 at 5:48 PM
Haha. Actually, I was going to buy it from Ikesound's eBay store. About $89+shipping
Posted By: customsuburb
Date Posted: February 10, 2005 at 6:41 PM
If you get the 4 ohm dvc then this amp would be a pretty good match for it. https://www.ikesound.com/product-product_id/2400 Wire your sub in parallel for a two ohm load and your set.
Posted By: boardinbum
Date Posted: February 10, 2005 at 8:03 PM
So when I wire the 300watt sub into 2ohms, what happens to the power?
Will it still want 300watts rms?
Posted By: Drewt
Date Posted: February 10, 2005 at 10:30 PM
yep, still 300 watts....
Posted By: boardinbum
Date Posted: February 13, 2005 at 2:08 PM
One more somewhat off topic question...
Some guy was trying to say it wouldn't be possible to hook a amp/sub setup to this Pioneer headunit. Does anyone see anything that wouldn't allow that? I think the words were "No preouts for subs"
But that's what preamp outputs are, right?
Posted By: DYohn
Date Posted: February 13, 2005 at 2:14 PM
That deck has front and rear pre-amp outputs. "No preouts for subs" is a true statement, although that does not mean subs cannot be connected, only that the HU does not include a crossover or level control specifally for subs. I suggest using the rear pre-outs run to your sub amp, and then activating the Low Pass (LP) filter on your amplifier. Set it to 80Hz (approximately.) Be sure to set the input level properly, and then if yu need to reduce the sub level to match your main speakers, you can use the fade control towards the front (which reduces the level to the rear.) ------------- Support the12volt.com
Posted By: tcss
Date Posted: February 13, 2005 at 4:22 PM
Not to rain on your parade, but I don't of any Toyota Reg cab pickup that an R series Alpine sub would fit into without moving the seat WAY up.
Posted By: boardinbum
Date Posted: February 13, 2005 at 9:12 PM
I think I've got the space thing all figured out.
Rough estimate of box plans:
19"w x 15"h x 8"d made with 0.75" mdf wood = 0.88867 cu.ft.
12" Alpine Type R specs:
Recommended sealed box volume: 0.7-1.0 cu.ft.
Posted By: ull3030
Date Posted: February 14, 2005 at 5:29 AM
tcss]N wrote:
t to rain on your parade, but I don't of any Toyota Reg cab pickup that an R series Alpine sub would fit into without moving the seat WAY up.
That sub might be too deep to mount in that shallow box -------------
Posted By: boardinbum
Date Posted: February 14, 2005 at 9:30 AM
top-mount depth 6-15/16"
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