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maka_RTH
06-06-2004, 06:42 AM
ok, here's the deal. I'm sure this has been asked plenty, but i did a search and couldn't really find any info on what i was looking for, so here goes. I'm gonna be getting 2 10" Infity Kappa Perfect Subs (DVC) http://www.crutchfield.com/S-IfzhAoUQhqU/cgi-bin/ProdView.asp?wm=fp&I=108PER101D&g=67600 I'm gonna have them in a sealed box. Anyways, the only thing i don't really know about car audio stuff is which amps are good quality and whatnot. So, i'm trying to find which brand of amps i should be looking for. money is no factor. they're rated at 350 W rms, so i was either thinking i could get two amps that can run 300-350 watts at 2 ohms, or one amp that will run 600-700 watts at 4 ohms. any info would be appreciatted. my second option would be to get a 12" Kicker L7, but i love infinity, so i wanna keep with the theme or whatever. thanks in advance.

shepherd79
06-06-2004, 07:38 AM
i always said that MONO amps are better when it comes to power the subs.
i am going to say go with mono amp that can hold 600watt.
I like Alpine amps, but it may be bacause i am Alpine fanatic guy.

bobsaccord
06-06-2004, 07:46 AM
i have two 12 inch mtx's and im running them on 250 watt amp and they pound! so get anything above 300 watts and u will have a nice system. just my .02 lol

Vanilla Sky
06-06-2004, 07:49 AM
i would say spring for a coustic amp

ivanfbi
06-06-2004, 10:09 AM
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=18797&item=5703151732&rd=1 ohh, this is a perfect one for job like you want, and also, make sure to run wires above 4gauge most probably 2g wire would be really good, but they cost an arm and a leg

shepherd79
06-06-2004, 10:59 AM
why would he want 1500 watt amp when he needs 600 watt amp

HondaBoy
06-06-2004, 11:24 AM
one thing to not to do is over power your subs. many of my friends have fried their expensive subs with an amp pushing too much power. i have two 250 watt 12's powered by a 500 watt 2 channel DHD amp i just got last week. it has good bump now, im sure i could go with a little more power. look to see if any amps you look at tell what power output is at when you hook the speakers up in different configurations. when its bridged it will put out more on a channel. i'm not real good on matching up subs to amps either, but i know not to over do it.

Moodybluesr
06-06-2004, 12:44 PM
If those are the subs you are set on, your options as far as resistance are as follows:
VC's in series, subs in series: single 16 ohm load
VC's in series seperate subs: two 8 ohm loads
*VC's in series, subs parallel: single 4 ohm load
VC's parallel, subs in series: single 4 ohm load
VC's parallel, seperate subs: two 2 ohm loads
VC's parallel, subs parallel: single 1 ohm load

My suggestion is to get a decent bridgable two channel amp and run the subs as marked with * above. That would probably be the solution that would give you the most bang for the buck.

Magny
06-06-2004, 08:19 PM
ok. ummm, guess you guys dont know that much about subs and all then. ummm, how do I put this..............uhhhh........oh yeah..............BTW this is gonna be a long one LOL...........here we go.

The amplifier is the workhorse of your stereo system. It is responsible for delivering electrical current to your speakers, while not destroying them. Simply put, if your amplifier is bad you will have bad sound. Even the best speakers will not hide crummy amplification. In fact, the ruthless accuracy of world’s best speakers will do nothing but highlight your amplifiers deficiencies.

How They Work..........
Conceptually, an amplifier has the job of taking an electrical waveform, and simply super-sizing it without changing the waveform in any other way. It should take a weak audio signal and boost it to generate a signal that is powerful enough to drive a speaker. The amplifier uses four tools to do its job:
1)A power supply.
2)An input stage, where the signal comes in from a preamplifier.
3)A driver stage, where the signal is amplified.
4)An output stage where the signal is passed off to the speakers via the speaker cable.

Technically, the amp uses its power supply to take Alternating Current (AC) coming from your wall outlet, store large amounts of this electric current as Direct Current (DC) in capacitors (or simply, "caps") and use the input signal (the musical signal output from the preamp) to modulate (control) the release of the electrical energy stored in the capacitors.

This energy released from the capacitors is passed thought the output stage, from which your speakers receive their signal and they convert it to sound energy. This output stage is composed of either transistors or vacuum tubes or a combination of the two.

Types..............
There are two main types of amplifier commonly in use today. First, is the solid state, or transistorized amplifier. This type of amp uses lots of transistors (little integrated circuits) to amplify the musical signal and output it to the speakers. Solid state amps make up 90% or more of the amplifier market. Generally these amps produce ample power, so transistorized amps are usable with almost all varieties of speaker, and generally perform very well. Solid-state amps exhibit great low-frequency performance thus strong bass is a hallmark of this design. (Poorly executed models can be grainy or harsh in the upper registers, and can cause “listener fatigue” due to this distortion of high-frequency sounds.)

The second, and oldest type of amplifier is the vacuum tube (or simply “tube”) amp. This type is so named because it uses vacuum tubes to amplify the signal received from a preamp. These types are generally built in far fewer quantities and are priced higher because of materials and manufacturing costs.

Tube amps generally have a particular quality of sound, typically called “the tube sound.” It’s a mellow, warm sound, very relaxed and strong in the mid-range. The lower registers (bass) are not usually as strong as the bass produced by solid-state amplifiers.

What To Look For..........
There are several key measures of amplifier performance, but the most important measurement that you need to be concerned with right now is maximum sustained power output in an 8- and 6- ohm load. The unit of output for amplifiers is the “watt.” An amplifier may produce from 3 Watts per channel (Wpc) RMS for a small tube amplifier to upwards of 500 Wpc or more for a large solid-state amplifier. When comparing amplifiers, make sure to compare continuous (sustained) amplifier power into the considered load. This is reported as “watts RMS.”(RMS, or Root Mean Square, is a mathematical formula that computes an average amount of wattage generated.) Also make sure the ratings are derived with “both channels driven,” meaning that both the left and right channels are delivering current during the measurement.

Amplifiers, even if they produce the same sustained power, are not the same.

For example take two amps, each producing 100 Wpc. This may be fine into the 8 ohm load, but what happens when you use that same 100 Wpc amp to drive a 6-ohm speaker which is a very common situation? Top-quality amps will double the amount of power from 100 to 200 Wpc into that 6-ohm load, and double it again (up to 400 watts!) into a 4-ohm load. A lesser amp may only deliver 150 or 160Wpc to the 6-ohm load, and may not be able to consistently drive the 4-ohm load without serious damage to the amplifier itself. This second amplifier is not very efficient, and would not perform well overall, while the first is what’s called a "perfect voltage source". The perfect voltage source is a very desirable amp indeed. Amps that operate as perfect voltage sources are usually large, heavy and expensive because to be this good requires high-quality power supplies, lots of big capacitors and many output transistors or tubes. As a general rule, lots of components equals lots of dollars.

What To Listen For...........
Your power amplifier is one of the most important links in the reproduction chain. It has to give clean power to your speakers in order for them to accurately replicate the sounds that were recorded on that great CD you just bought last week. The best way to review it is ask your dealer to take it home for a weekend and give it a good testing with your speakers and electronics. During this test, look for high performance in the presentation of the music by the amplifier. A good amp should present the music in a “forward” fashion. You should feel like the musicians are right in front of you. Provided your speakers are in the right position, you should almost be able to see the relative positions of the musicians when they recorded the piece. In other words, you should have an accurate “soundstage.”

It should also have excellent “pace”. When listening to a quality amp, the tempo will be constant. You’ll literally feel moved to tap your foot or snap your fingers to the beat. Part of that pace is adequate power to faithfully reproduce bass drum whacks and other loud “transients.” This ability is a key to musical realism. If the amp you are auditioning seems to "wimp out," "clip" or sound less explosive during these transients, you’re not going to be happy.

Give your target amp a good workout prior to purchase, and you’ll see what its capabilities are BEFORE you spend your hard-earned dollars.

Many people wonder what the big difference is between power amplifiers. Most buyers simply say "I want an amplifier that puts out 100 watts per channel." Why? Because the number "100" is an even, well-known number. Then they look for a name that they recognize like Sony, Pioneer, or Kenwood, and call it a day. We now know that amplifiers that should double their power output when speaker impedance is cut in half. So for example, the amp that delivers 100Wpc at eight Ohms should put out 200Wpc at four Ohms. But why is it that way and how do you tell if your amp performs as a perfect voltage source?

First, to fully understand the difference, you must realize that we are comparing not raw numbers but ratios of output power.

There is an easy way to understand this, and that is the concept of the dBW or "decibel watt." The dBW rating conveys the ratio of amplifier output referenced to one watt (1W) of output power. 0dBW simply means that the output of 0 dB is referenced to one watt of output.

Recalling that a doubling of power output in an amp leads to an increase 3dB, then an amp producing two watts output power has a 3dBW rating. An amp with 32W output power has a 15dBW rating, and so on. Now to calculate the dBW rating, you need a pocket calculator with a "log" key. Simply punch in the numberof watts that you want to convert to dbW, press the "log" key then multiply that result by 10. This gives you the dBW rating of the amplifier driving an eight Ohm load. To determine the same rating for 4 ohm output, simply subtract three (3) from your 8 Ohm dBW rating .

You can use this calculation to see if two 100Wpc amps are actually equal, at least in a raw power sense. For example, you're auditioning two amps both rated 100Wpc into 8 Ohms, but you just realized you're buying a pair of speakers whose impedance is 4 Ohm. You see that one amp delivers 150Wpc into the 4 Ohm load, and the other 220Wpc. Your first reaction is that its not a significant difference. But then you perform your calculations and you'll see that amp one has a 18.7 dBW rating while amp two has a 20.5 dBW rating! Remembering that a 3 dB difference is a doubling of power, the difference between the second amp and the first becomes more relevant. The second amp is nearly twice as powerful into your 4 Ohm load as the first.

All those computations say that the second amp will have a problem driving the the low-impedance load, specifically by not delivering enough current and that has a strong influence on the amplifier's sound quality. So you see, not every 100Wpc amp is same!

*NOTE TO MODS* you can put this in the FAQ forum if you want.

Magny
06-06-2004, 08:38 PM
Also many people wonder if an amplifier can blow their speakers when delivering full power to the speakers. The short answer is "No." The long answer is "well, if your amplifier is high-quality, you are OK." With power-handling, a higher rating is like almost everything else: more is always better. A speaker might have a minimum requirement for power handling, based on its sensitivity and performance, but will most likely have a maximum allowable amount.

A speaker with a 100 watt power handling rating can be safely operated when connected to a 500 watt amplifier. The speaker is not going to explode or anything like that. The truth is that high amplifier power almost never destroys a speaker. In most cases, it is a lack of amplifier power that causes damage. The key is to use your speakers with an amplifier that produces sufficient output to drive the speakers to realistic sound volumes without distortion, or "clipping."

Clipping occurs when the amp is asked to deliver more current to a speaker than the amp is really capable of doing.

When an amplifier clips, it literally cuts off (or ... clips) the tops and bottoms of the musical waveforms that its trying to reproduce. This phenomenon introduces a huge amount of distortion into the output signal, and it is that distortion that kills speakers. The maximum power-handling amount stated on a speaker basically assumes that the amplifier is going to "clip" or start to produce distortion at its maximum output. So, if you use a low-quality amplifier, it will start to run out of gas at its max output, and might do damage to your speakers.

A high-quality amp usually produces ample power without clipping and thus it avoids the introduction of speaker-killing distortion.

ivanfbi
06-06-2004, 10:50 PM
ok, shepherd, here is a great 600w amp http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=39734&item=5702611364&rd=1
I have a kac-929 kenwood amp, and that thing is so damn great, I LOVE it. so I would be sure that MAKA-rth will be satisfied with quality of those amps.

shepherd79
06-07-2004, 03:44 AM
magny, you don't have to explain us what the amp does and how it works.
if you really want to explain and get your fingers some work out go a head, but othet than that, just give him this link http://www.bcae1.com/ it is a great site.
i know about stereo a lot. i have building my own circuit board amps when i was 10. when i found that site, i learned a hole lot more info about stereo and how to tune it properly.

maka_RTH
06-07-2004, 07:43 AM
ok, let me try to rephrase the question. first, assume all power output is continous. second, i am getting a mono amp(s), so no 2+ channel amps. question one: should i get one 700W @ 4 ohms, 2 175W @ 4 ohms(350W @ 2 ohms), or 1 175W @ 4 ohms(700W @ 1 ohm, assuming it's one ohm stable). and, question two: what brands of amps are good quality? i know what speakers/head unit i want, i just don't know what brands of amps are good and which ones are cheap (quality wise).

DanLXI88
06-07-2004, 08:06 AM
Your best bet is to buy one from Crutchfield and if it don't sound good to you send it back and try another brand. Most of the AMPS they have on the site are good even Profile (arguably).

N-Man
06-07-2004, 08:39 AM
my friend has one of these (http://www.caraudioexpert.com/productView3.asp?productID=3689) and it is definitely worth the price.

blahblahblah
06-14-2004, 12:39 PM
Look at some HiFonics. My brother has his car full of them. With all Audiobahn speakers and it sounds really clean.. And loud...

BlueBead
06-14-2004, 12:48 PM
wow magny, that was some post. I've been wondering about the overpowering issue, and its nice to have it cleared up for me..... My amp is rated higher than my subs and I was going to check on that before I put them in my Honda. - You've just saved me alot of effort! Thanks!

Magny
06-14-2004, 09:33 PM
wow magny, that was some post. I've been wondering about the overpowering issue, and its nice to have it cleared up for me..... My amp is rated higher than my subs and I was going to check on that before I put them in my Honda. - You've just saved me alot of effort! Thanks!


no problem, it took me a while to put that info up, but then again, I could of put it on my website and just provide a link to it. oh well, whats done is done, glad to help out.

maka_RTH
06-21-2004, 02:44 PM
^bump^ anymore good brands of amps?

zero.counter
06-21-2004, 02:52 PM
Just buy one of mine in the for sale section! :)

Neuspeed87lx
06-23-2004, 07:31 PM
i have a sony xploid 800 watt amp powering 2 15 inch kicker comps......... well worth it .... its a great amp ....def recemend it

87AccordsterLx
07-12-2004, 01:06 AM
If you really want competition quality sound go with an Eclipse amp. The THD is 0.1% @4ohms. It might not look like a lot of power but it will be the cleanest sounding bass.

http://www.eclipse-web.com/products/amp/34230.html

This is their power series....

http://www.eclipse-web.com/products/amp/da7232.html

accordfever
07-16-2004, 11:56 PM
if your subs are DVC and you want to get the most power out of them, then you need at least a 1000 watt amp or 2 500watt amps.heres why, DVC is composed of 2 4ohm voice coils when you run them with + going into + on the other voice coil of the same sub you create a 2ohm load same wiring is done with the - . RMS is really not what you want to go by the only the that RMS is telling you at the majority of the time that the sub is playing it will put out a certain amount of wattage, if I am not mistaken the RMS on Infinity is 375watts but the peak is above 1000watts. 375 watts will just get the sub moving at decent rate so you can get some decent sound. Currently I'm running Bazzoka EL-1500 600watt mono block amp this amp is great a lot of people talk bad about them but I love the performance of it, I've had the amp for about 3 years now and the only time it overheated was on a drive from Vegas to Reno ran the sytem for 4 hours straight loud, turned it off for an hour haven't had a problem since. No matter what speakers I have used with this amp it plays great a clear 2 12" MTX Thunder 4000, 2 12" MTX Thunder 6000 or my current sub just bought yesterday Bazooka P. Miller 12" DVC sub which is louder than both MTX THunder 6000 together. The reason to by DVC is so that you can have one sub putting out the same sound as 2 subs so if you have 2 dvc subs then it is like having 4 subs so you need an amp that will handle what those subs need, I will say that a seperate amp on each sub will be your best bet or wire it up as a single voice coil sub in which takes all the fun out of having a dvc sub. By the way I will try to enter my car into a sound competition this Sunday if I get out of church in time. Wish me good luck.

PortugalFocus
07-17-2004, 07:44 AM
I have a 4 channel American Legacy 1200w running a 4 ohms powering my 2 Audiobahn 1200q (quad voice coils) in a Q-Logic 1.25 cu/ft box and they slam wicked hard. Legacy is a not a flashy name brand but they are quality and I love them.

Ludi Mali
07-22-2004, 03:48 PM
depending on price, cadence and orion make some really clean sounding amps, I'm also happy with my directed 750d running my subs.

AccordEpicenter
07-22-2004, 05:50 PM
Ill tell ya ive always been REALLY impressed with Orion and Cadence, directed is also a great amp that alot of people dont know about... HiFonics too. For the cheapest amp that seriously thunders, Lanzar Vibe 1200d is a hell of a value, you can prolly get one off ebay for $160 or less used but damn. Mine sounded good (ive heard some amps like PPi or Eclipse/phonenix gold sound clear) but holy shit, it put out 1280wrms at 1ohm mono letting me hit 147 with 2 kicker comp 12s... from my trunk. That shit was loud.

Ludi Mali
07-22-2004, 06:20 PM
i should probably check my spl, all i know is my whole face vibes, vision can get a tad blurry, and everyone says it hurts their ears except for me and my metal head buddy