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Andrew
Dodge Dakota
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11/02/2003
13:59:13
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 Subject: What amp do i need
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I'm new to car audio and I was wondering what amp I should buy to power 2 kicker S10L7 subs. Also should I buy them with 2 ohms or 4 ohms
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crash39629
Dodge Dakota
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11/09/2003
20:04:47
| RE: What amp do i need
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a kicker zr120 or zr240 will power your speakers quite well. a good thing to remember is the lower the ohm the more power you pull out of your amp. you just have to make sure you amp is stable at the low ohm level. it should tell on the specs. if you get two 2ohm speakers and wire the parallel you end up with a 1ohm load on your amp.
two 4ohm wired parallel you get a 2ohm load. i hope this helps
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Matt
Dodge Dakota
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11/09/2003
21:34:21
| RE: What amp do i need
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I'd say go with 4 ohms. I wish that 8 ohm subs were still available. When wired in parallel, they present a 4 ohm load to the amp. Assuming you are running the subs in mono, a two channel amp sees this load a 2ohms /channel. I'm not a big believer in loading amps much below two ohms. Reason? Huge current draw, and poor voice coil control when amps are loaded harder. Try this test if you have the chance: Audition a subwoofer in both 4 and 2 ohm versions. Chances are the 4 ohm sub will sound tighter. Yes, there is more power to be had when lowering impedence, but how much power does one need? An audio engineer once said that no man has heard 100 watts RMS and lived to tell about it. :)
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92Dakota
Dodge Dakota
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11/10/2003
00:59:03
| RE: What amp do i need
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Haha...I hope you were joking Matt.
If not...DON'T give advice if you have no idea what you are talking about.
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cassetti
Dodge Dakota
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11/10/2003
13:13:54
|  RE: What amp do i need
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.... wow matt - well said well said - spoken like a well informed (by car audio salesmen at your local best buys) as i can see.
That audio engineer must have been hanging out with bill gates when he said that - i quote bill gates (1978)
"612kb of ram is all that we will ever need"
-------------------------------------------------
Asuming those subs are dual voice coils - then get 2 ohm.
1 ohm is PERFECTLY fine for a final impedance IF you are looking to go with a good higher end mono amp.
if you want real advice - email me and i'll send yo to another forum that may have some more knowledgable people on it
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Matt
Dodge Dakota
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11/15/2003
00:31:21
| RE: What amp do i need
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Hey '92 Dakota, why don't you explain to us why in the hell anyone needs so much power? Are we talking about listening to music that sounds good, or trying to piss off all of the neighbors?
And I'll admit I am no expert on car audio, and it has been awhile('95) since I had a system put in a vehicle. That was a '95 B4000 Mazda truck with Boston Acoustics Pro separates front and rear, and two Kicker Solobaric 10's. The subs were run by a RF Punch 100. They were 8ohm subs wired parallel. The BA's were run by a RF 400x4. It was plenty loud, and the bottom end was great. Notice no super low impedances used.
And I have listened to many, many systems lately. I still don't like the way subs sound when they are being driven by an amp loaded to below two ohms.
I'm shopping for a system for my new Dakota right now. I'm leaning toward JL speakers, and using a single 10" W7 for the low end. Any comments?
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92Dakota
Dodge Dakota
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11/21/2003
23:38:23
| RE: What amp do i need
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If 100rms kills people, then how do we live with something as weak as an aftermarket head unit? They usually put out about 100rms when all channels are driven.
By the way...it seems like your old system had quite a bit more than 100rms.
No, I don't piss off the neighbors. If I ever have a lot of power, its usually to compete.
There is no difference in sound between 1 ohm and 2 ohms unless either amp is driven past its limits. I don't feel like explaining this any further.
JL makes very nice equipment. The Adire Audio Brahma 10" is a good alternative if money is an issue. Same specs almost.
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Dukk
Dodge Dakota
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11/22/2003
11:09:08
| RE: What amp do i need
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Matt - that Punch 100 used to put out a little over 400rms at 4 ohm mono... No wonder you liked it.
I think the point you are trying to make is to optomize the impedence of the woofer system to the amplifier. That Punch 100 wanted a 4ohm mono load and you gave it that so it worked dandy. Many current mono amps are optomized for 2 or even 1ohm loads so if presented with such they will run great and sound fine.
And you can still find 8 ohm SVC woofers or feel free to buy a 4ohm DVC and wire them in series for an '8ohm' speaker.
92Dakota - you're being a little generous with the headunit ratings but I can see the point you are making. Many aftermarket decks might make as much as 25watts rms but only with a single channel driven into heavy clipping with a test tone. With all 4 channels driven with music I would not expect more than 10-14watts RMS per channel, or ~50 watts rated total rms power on the outside. A 10 amp fuse on the deck would also say that you can't really get much more :)
Also - what he heard about the 100watts thing is probably 'acoustic' power. As you probably know, only about 3-5% of the power fed to a speaker is converted to sound, the rest is lost as heat. That means to hear 100watts acoustic power would take in the range of some 2,000watts+ rms rated amplifier power. Few systems are capable of actually playing full range sound with that kind of jam but even so they won't kill you.
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Matt
Dodge Dakota
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11/22/2003
23:24:00
| RE: What amp do i need
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Dukk:
That is what I was trying to say. I was almost going to get into an argument with 92 Dak, but thought the better of it. My point is: Why drive amps so hard that they draw tons of current from your electrical system, when you really don't have to? And hey, I enjoy getting loud from time to time. Ever try listening to the Who at a sane volume level? It just doesn't sound right!;)
The 'acoustic power' thing, was exactly what the engineer meant, I think. Lately, I'm having trouble convincing installers that I don't want a vented box. I prefer acoustic suspension enclosures for tighter lows. I am rather fond of organ music. I want the 16-32hz pedal tones to be heard and felt as individual pulses of energy. Unless one ports a box at a SUPER low frequency, those poor subs will be flapping around like they're in free air below the tuned frequency. I know. I lost a couple of subs from this. The spiders tore. OUCH!
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92Dakota
Dodge Dakota
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11/24/2003
00:15:12
| RE: What amp do i need
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Ok...
Dukk...
I have read reviews on head units. They drive all four channels with less than 1% THD and determine the output power per channel. I have seen up to 27wrms per channel.
I realize that this is about the most you will be able to get from a head unit due to the absence of a switching power supply. So, you are stuck with the voltage that is supplied from the battery.
A 10 amp fuse doesn't seem like information that would back your claim. Using something as simple as Ohm's Law....
Power = Voltage x Amperage
14 volts (battery) x 10 ampere fuse = 140 watts
Multiply this by the 65-70% efficiency of the internal amplifier and you end up with about 100 watts total output power.
Matt...
Get in an argument over what? What do you not agree with?
It would have made a lot more sense to specify that you were talking about acoustic power.
I still don't really get what you are saying about driving amps hard and drawing current from your electrical system.
Unless you have a lot of air displacement, I doubt that you will be hearing 20-30 hertz tones in a sealed box.
If you want that kind of low bass, you need a low tuned ported enclosure (around 25-30 hertz). In sealed enclosures, most drivers can not move enough air to properly reproduce very low frequencies.
If you kept ripping spiders, you should have considered a subsonic filter to block frequencies below the tuning frequency of your enclosure.
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Matt
Dodge Dakota
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11/27/2003
12:03:31
| RE: What amp do i need
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92Dakota:
What I mean about current draw...An amp draw alot more current when it is worked harder, right? I mean, the manual for both of the RF's that I owned stated that if each channel were driven to their lowest stable impedance, they would pull HUGE amounts of amps. I had a 1 farad cap in that system, too.
About the deep lows: The best super deep lows I've heard were from a sealed box. My home system uses a Velodyne HGS-12" powered sub, and that little monster makes the whole house shake during some of my sicker organ recordings. BTW, if you want some bass, you should hear a CD I have. It's a recording of the largest organ in the world. It's in Atlantic City, NJ's convention hall. One track on the CD is a demonstration of the 64' stop. Descending the pedal board, the botton note is 8hz!!
And yes, a subsonic filter would have saved my PF Punch 10's. That box was vented at 35hz. My new Dakota CC will probably get a MTX Stealth box, with different subs. I just like the way it saves space. Any other ideas? What works in your Dak?
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92Dakota
Dodge Dakota
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11/27/2003
19:42:27
| RE: What amp do i need
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I'm not sure what you would like.
I am more of a basshead....so I am not too obsessed with sound quality. My whole backseat area consists of audio equipment. No seats. I don't like hauling people around anyway :) So, I am not the person to get advice on as far as space-saving setups go.
The only other way I could think to do it is...
Flip up half of the backseat (its a 60/40?)
Then build a box and leave one seat up so the box can sit there. Atleast you will have a deeper mounting depth. Maybe you want it to be smaller and hidden, though.
They have a few test tone generators on the net. You can just enter in the frequency and burn it to a CD. Then play it in your home theater or truck to see how it sounds.
What's your budget for subs and amp? I have a lot of used equipment sitting around that may work for you. Nothing fancy.
I get bored and change systems all the time. Here's a few...
http://images.cardomain.com/member_images/2/web/218000-218999/218281_37_full.jpg
http://images.cardomain.com/member_images/2/web/218000-218999/218281_48_full.jpg
http://images.cardomain.com/member_images/2/web/218000-218999/218281_10_full.jpg
http://images.cardomain.com/member_images/2/web/218000-218999/218281_123_full.jpg
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