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What amp to purchase and other things.

post #1 of 19
Thread Starter 
First off, hello everybody. This is my first post and I would like to say everybody here has been a major help in the past from just reading around on the forum whenever I have a question about speakers and subwoofers and the like.

Anyways, currently I am running a Ported Box (Which is for my new subs) with two 12" Kenwood subs (KFC-W3011) and an 800 Watt Kenwood amp (Forgot the model number, but if its crucial, I will find it) and they are just not loud enough for me anymore. I consistantly have trouble tuning the amp and don't know exactly what all the knobs do, but I do know what all the switches are for. I tend to just mess with them 4 or 5 times a day to find the best sound, and once it gets to quite for me, I mess with them again and make myself think I made them louder.

Well, I want to buy bigger. Plain and simple, eh? I only want to get 12" subs and only two of them. I am not made of money, but I do have a decent job and am willing to save up for them. I was thinking of the new Rockford Fosgate P3D2 series, since I can find them on Ebay (Which a friend bought and they are BRAND new) for $125 each. I want loud, like, very loud. Loud to the point that people inside the gas station of me filling up feel like they are in my passenger seat. I know a decent amount about subwoofers, but I am still clueless on a bunch of things. I have no idea what amp I will need for the two Rockford Fosgate Subwoofers and this is where I need your guys help. If you think you know of a louder bigger better speaker for me that is not much over $125, PLEASE feel free to let me know. If you have any questions for me, feel free to ask. It is, well, a forum. :P

-Garrett
post #2 of 19
What type of vehicle?

In this vehicle, how much space is available for an enclosure?

Main type of music you listen to?

You are wanting a new amp correct?

What is the total budget?

I don't know the subs you are using or the amp. Posting the model number will help in letting us know what you are exactly running power wise.

Let's assume your amp is putting out 800 watts into those two subs. Doubling the power with a new amp will yield a 3 db gain in output. This is not a huge gain. Barely noticeable really.

New subs might make a difference in the same enclosure you are using, but chances are, that will be minimal.

To make a real difference in output, I suggest a custom enclosure designed around whatever subs you get.

For a decent powerful budget amp, look at audio pipe. They have a 1500 watt mono amp that will power the bejeebus out of the subs. I can link a model number if you like.
Edited by cubdenno - 1/12/13 at 10:55pm
post #3 of 19
Thread Starter 
The vehicle I am using is a 1998 Cavalier LS.

I have a vented enclosure I am using right now, and I had to get the box in the trunk without the amp first because I have no more room, lol.

I mainly listen to Rap and Dubstep.

I am looking to purchase an amp for the new Rockford Fosgate P3D2's I am getting. They are 12 inch subwoofers and I will be purchasing two of them. Here is a link to the specs.

The budget I am around is 200$ for the amp. I found the subwoofers on Ebay for 125$ each and they are brand spanking new (A friend had bought 2 of them a month ago and just purchased 2 more).

I assume I will need 2400 watts or more to power two of these Rockford Fosgate P3 subwoofers, but that's just from what I have been told. Have been looking into the Clif Design Amps. Specifically the one in the link.

The only reason I posted the current subwoofers is to show what I have and what I am purchasing. The friend that bought the 4 Rockford Fosgate subs that I am purchasing also had 2 of those in the enclosure I have currently for my setup (Bought the enclosure for that reason) and he had it custom built by a car audio business in my home town, but due to how rude the owner is, he decides to jack up prices for people he doesn't like. Number 1 reason why I come here.
post #4 of 19
http://www.amazon.com/AUDIOPIPE-AP15001D-1500W-Audio-Amplifier/dp/B002RE87UC/ref=sr_1_1?ie=UTF8&qid=1358094879&sr=8-1&keywords=audiopipe+amps

This amp should do even better than the clif designs amp you listed.

Also, I suggest dual coil four ohms per coil if you are running two 12's.
http://www.sonicelectronix.com/item_13864_JBL-GTO1214D.html
These will perform as good or better than those fosgates. And save you some cash!

Give a look at these

http://www.amazon.com/SA-15-D2-Sundown-Series-Subwoofer/dp/B004ILQJ20/ref=pd_sim_sbs_e_4

A single one of these will pound harder than what you are used to.


Also when looking at amplifiers, DO NOT read the max power ratings. They are marketing lies. Also for your listening needs, you want a class D amp. Your electrical system will thank you.

You are getting toward the power requirements that will need extra batteries and a high output alternator.
post #5 of 19
Thread Starter 
Now would that Audiopipe amp run two of these JBL Audio subwoofers to maximum power? The two Kenwoods I have right now are really loud (At least they were when I first got them), and outside of my car with all the windows rolled up, the only thing I can hear for bass is my trunk rattling. I want people to KNOW I have subs. I am a sucker for low deep bass, and want to make sure it hits everything I throw at it, including be loud as hell. The kenwoods don't hit some of the lower bass notes, for example, in Tyga - Faded, as well as some other rap songs. I want to make sure I am going to be happy with these next subwoofers I purchase because the Kenwoods only lasted me about 3 months before I wanted to buy new ones.

I have noticed that there is a decent amount of difference between the RMS on the JBL and the Rockford Fosgates. The Fosgates have a higher RMS rate. I don't mind spending quality money on subwoofers, I just don't know damn near anything about amps. Just wanna make sure my subwoofers are loud as ****, and I don't have a problem turning them up to full power after I break them in.

Also, as a side note, a friend is putting two 12 inch MMat Juggernauts in his trunk at max power. He is going for a state record here in Wisconsin. xD
Edited by iBlackSunday - 1/13/13 at 12:48pm
post #6 of 19
State record in what?

SPL?

Two twelves are not gonna cut it unless it is for a specific class that specifies "just two twelve inch subs"

There are two things that a subwoofer can be rated electrically for.

Thermal and mechanical. Now your enclosure can help dictate the mechanical by keeping the woofer from over excursion by way of the air in the box as it acts as a spring.

Thermal ratings are X number of watts will cause the coils to melt.

A sub does not put out watts. You feed it watts or rather voltage and current and the woofer puts out sound that is often measured in decibels.

The specs between the fosgate and JBL are a bit different but the end result will not be much. The max wattage is fairly close so for ground pounding you should be fine.

Either sub should work fine for what you are wanting. As long as the enclosure you are using is compatible with the sub and goals. If its tuned to high you lose out on low end. If the ports are not adequately sized for the power you are feeding the subs, you lose the benefits of using a ported enclosure.

As for that amp, if you get two of the subs of either brand, and the coils are dual four ohm, wiring the subs coils parallel for a one ohm load at the amp will feed 750 watts-ish per sub. When running at max power.

You never did give me a model number of your current amp.mtgere may be a reason why you are not happy.

My son and I are getting ready to do his new to him car using most of his stuff from his old car. We will do the install this spring. I will post pics of what we do.

3000 watts on two digital designs 9012 subs in a PWK designed enclosure
125 watt X4 channel amp running eight inch mid bass in the kicks and 6 inch mids and tweeters in the door and dash. In the Buick park avenue he metered sealed legal 149db. Which was not shabby for a big car with subs in e trunk. He is saving up for the new alternator and three batteries. 3 kilowatts pulls a lot of current. Especially if you are ground pounding.

Hope this has helped you understand a bit more.
post #7 of 19
Thread Starter 
Sorry I haven't responded lately. I am a delivery driver for a local pizza shop and I work CONSTANTLY. Back on topic.

The amp I am using right now is a KAC-7201.

A friend told me he is trying to break the state record for loudest sound in a vehicle. I told him I think it's a flook, but he still things he is going to do it. He told me it doesn't really matter the size of the woofer but what does matter is the amount of power it can handle and how the box is built. Again, my lack of knowledge on these subject cancelled the conversation out and I couldn't get further with him.

What is SPL?

So how can I make sure an amp I am going to buy is going to fully power the subwoofers I am going to buy. I heard it depends on the fuses. For instance, 2x40 amp fuses = 960 RMS. Is this correct? I am thinking of just waiting until taxes to come in so I can buy some Digital Designs. Is there a difference I will be able to tell if I buy DD's instead of Rockford Fosgates or JBLs?
post #8 of 19
Nice amp. 150x2 amp. If you can, keep it to drive your interior speakers.

SPL=sound pressure level Generally they use a decibel meter to measure the loudness of a vehicle or rather now days, they use a term lab meter.

DD makes good subs as does Sundown, Fi, and half a dozen other brands.

Enclosure is going to make the most difference.

Pwkdesigns.com. Does awesome enclosure design for cars. Pete is amazing.

How to tell....

An amplifier puts out X watts into a specific load. Your amp bridged mono puts out 400 or so watts into a 4 ohm load or stereo, does 150 x 2 into a four ohm load and 230 or so into a 2 ohm load

Now take a subwoofer single four ohm voice coil. Your current amp will power a single four ohm sub with 400 watts. Or two 8 ohm subs wired parallel to achieve a four ohm load at the amp with 200 watts each sub for a total of 400 watts.

Now that audiopipe amp does 400 ish watts into a 4 ohm load as well. But it does about 900 into a 2 ohm load and 1500 watts into a 1 ohm load.

So to run two subs at max power, you want dual voice coils that are 4 ohms. This will provide four coils that you wire parallel ( each coil wired to amp) for a one ohm load at the amp.

Make sure your subs can handle about 750 watts and you will be fine.
post #9 of 19
Thread Starter 
I feel like the amp I own is not that good and that it isn't powering my subwoofers enough to pump out enough power. I can turn everything up on the amp, and it starts causing the subwoofers to pop and not make good sounds in general. Does that mean that this amp is more powerful than the subwoofers can handle or are the subwoofers trying to pull more power from the amp and are causing the amp to clip?

A friend of mine has a used Fosgate Power 1000.1BD that he said I could purchase. He has no idea about anything amps and said I could buy it for 100$. I don't really know amps, but should I purchase it? I mean, I don't want to get ripped off, ya know. Even to just buy it and resell it.

Why should I stick with a Class D amp?

On a side note: So lets just say I will be purchasing these items in the near future. Would they work flawlessly? Will I need to purchase a capacitor? Should I have a custom box built? Will this cause me to not have a rear view mirror (LOVE when it rattles so much, the mirror won't stay in position for more than 2 seconds). Will people be able to hear me a block away?

http://www.amazon.com/AUDIOPIPE-AP15001D-1500W-Audio-Amplifier/dp/B002RE87UC/ref=sr_1_1?ie=UTF8&qid=1358094879&sr=8-1&keywords=audiopipe+amps

http://www.sonicelectronix.com/item_13864_JBL-GTO1214D.html


I am sorry for all the questions, I am just seriously into all these things and I am trying to figure out how I can tell if amps or subs are good or ****. For instance, I heard L7's are amazing, but W7's are not, but what makes one worse and the other perfect? I am starting to understand amps though, and how to figure out what is going to work perfect and such.
post #10 of 19
Answers in blue

Quote:
Originally Posted by iBlackSunday View Post

I feel like the amp I own is not that good and that it isn't powering my subwoofers enough to pump out enough power. I can turn everything up on the amp, and it starts causing the subwoofers to pop and not make good sounds in general. Does that mean that this amp is more powerful than the subwoofers can handle or are the subwoofers trying to pull more power from the amp and are causing the amp to clip?

Don't use bass boost or at worst, a tiny tiny amount) and the amp gain turned up, you are probably clipping the hell out of the amp which in turn is making your subs sound like ass.

A friend of mine has a used Fosgate Power 1000.1BD that he said I could purchase. He has no idea about anything amps and said I could buy it for 100$. I don't really know amps, but should I purchase it? I mean, I don't want to get ripped off, ya know. Even to just buy it and resell it.

How was it treated? Does he run it the same way you run your current amp? What does it look like?

Why should I stick with a Class D amp?

Because Class D is more efficient with the cars electrical. Most Class D amps are anywhere between 70 and 90% efficient with the power they draw. Class AB amps are 30-50% efficient. So to make 100 watts it take 200 watts or more from your alternator and battery.

On a side note: So lets just say I will be purchasing these items in the near future. Would they work flawlessly? Will I need to purchase a capacitor? Should I have a custom box built? Will this cause me to not have a rear view mirror (LOVE when it rattles so much, the mirror won't stay in position for more than 2 seconds). Will people be able to hear me a block away?

http://www.amazon.com/AUDIOPIPE-AP15001D-1500W-Audio-Amplifier/dp/B002RE87UC/ref=sr_1_1?ie=UTF8&qid=1358094879&sr=8-1&keywords=audiopipe+amps

http://www.sonicelectronix.com/item_13864_JBL-GTO1214D.html

I would never give the the guarantee that the stuff will work flawlessly. Especially if I am not the one installing or setting it up. I also believe no one else would for the same reasons. That would be silly. And those who would, you need to tread warily around them. If you install the amp correctly and whatever subs you buy, install them in a correctly designed enclosure, you should be very happy. Will the system do hair or bottle tricks? probably not. Will you be heard from 2-3 blocks away? yes. Will you annoy people? I hope you show some restraint at night and not be an ass ticking people off and giving towns reasons to pass more noise ordinances. But you will have that capability Remember that line from Spiderman, "with great power...." Just be responsible.

If the equipment is good (remember even great companies can send a faulty product) you should be happy


I am sorry for all the questions, I am just seriously into all these things and I am trying to figure out how I can tell if amps or subs are good or ****. For instance, I heard L7's are amazing, but W7's are not, but what makes one worse and the other perfect? I am starting to understand amps though, and how to figure out what is going to work perfect and such.

Generally application Dependent. The W7 subs are amazing. Very well engineered with a ton of excursion capabilities. Used in award winning cars, home audio, bad ass theater/monitor applications. Expensive

L7 subs get the bad rap of being SPL only subs. They can also get loud and sound good. Just have to put them in the correct enclosure.

If it hasn't become apparent yet, the enclosure will make or break a subwoofer. There is no magic. Just working within the laws of physics. Utilizing acoustics in your favor. You can spend a grand on a single sub and in a bad enclosure design have it sound worse than a 15 dollar flea market sub.

What model of subwoofer are you running?
post #11 of 19
Never mind on the what sub question. I went back and saw you posted that.

You are running 2 12" single coil 4 ohm per coil subs on a 150 watt per channel stereo amplifier. So unless I missed something, that amp will not run a 2 ohm mno load and survive long, you are running each sub on its own channel. So each sub is getting at a max, 150 watts each.

If you have a link to where I can look at the enclosure you are using, I would appreciate that.

Here is how I would approach this.

Buy that amp (Audiopipe)

Swap your amp for the Audiopipe. Wire speakers to it. You will be feeding around 900 watts to those subs. See if you like it.

If it's enough, call it a day and jam.

If you want to replace the subs after because you want more, I would suggest at that point looking at another enclosure. Changing subs may give you a bit more every thing else being equal, but the combination of a better enclosure and dual 4 ohm coils to get that 1500 watts may give you a bit more thump.

Whatever you do... make sure you have adequately sized power wire. For that aUDIOPIPE, you will want 1/0 from the battery.
post #12 of 19
Thread Starter 
I don't want you to think I abuse my amp and my subwoofers. If they don't sound good, I turn the amp down enough so the popping and such stops. I understand what clipping is and how it happens and stuff, that is why I don't have bass boost and stuff on. I have messed around with the amp to see what it can and can't do and I realise that amps, even if they say they can pump out a **** ton of power, they sometimes can't. For instance, this 800 watt kenwood amp. I have the subwoofers wired to the left channel (Mono) and they are bridged together. One sub is connected to the other sub, and that sub is wired to the amp.

Thge amplifier the friend is trying to sell me was received when he bought a car from a police drug bust in Minnesota (We are in Wisconsin) and the only other thing I found in the car that would tell me the guy knew what hewas doing was that there was an extra battery in the trunk next to the spare tire. After looking at the knobs on the amp and they are all turned down so the amp seems like it wasn't abused. There isn't a single scratch on the amp, so it looks in perfect condition.

The box was custom built from a local audio shop for two 12" Fosgate P3. I will get the dimensions. I am pretty sure my kenwood amp isn't pumping out the amount of power it needs to for my subwoofers, but the subs pound hard as hell. I'll get back to you when I get off work. I am using a co-workers PC. :P
post #13 of 19
No worries man, Glad you are working.

No judgement. I have a 20 year old son. And between him, my 16 year old nephew and ALL their friends, I see what can be abused. Most of the time they don't even know it.

Just so you know, I hate to type. To easy to misread and think I am being a jerk. Never my intention. There is no doubt at all that I am being a jerk when it happens biggrin.gif

I would love to see a picture of the wiring of the subs into the amp. Or if you have a multimeter take an ohm reading of the sub speaker wire at the amp disconnected.

Anyway, I agree that your Kenwood is not the amp to power your subs to your liking.

If the Fosgate amp works, it should power your subs fine. it does 1000 watts at 2 ohms which is perfect for your subs.

I say try it!
post #14 of 19
Thread Starter 
To explain how the subs are wired is like this:

Left and right speaker have they're own wires. Both negative and both positive wire of each speaker is wired to the left channel of the amp. Everything else is normal for power, ground and remote. That causes the amp to be on mono. To bridge it I would need it to be negative on left channel and positive on right channel.

The fosgate amp comes with an amp controller (Which I always wanted). Would the amp work just the same without the controller?
Edited by iBlackSunday - 1/17/13 at 1:20pm
post #15 of 19
Quote:
Originally Posted by iBlackSunday View Post

To explain how the subs are wired is like this:

Left and right speaker have they're own wires. Both negative and both positive wire of each speaker is wired to the left channel of the amp. Everything else is normal for power, ground and remote. That causes the amp to be on mono. To bridge it I would need it to be negative on left channel and positive on right channel.

The fosgate amp comes with an amp controller (Which I always wanted). Would the amp work just the same without the controller?

Amp controller is usually a remote gain control. You set the gain at the amp to say half. run the remote and now you have a way to control the sub amps output.


Sounds to me like you are just running the amp stereo and powering your subs from a single channel at 2 ohms.

Try taking one of the subs and connecting to the right channel normally. IF I am right, you will actually have more power going to your subs. Not audible but more.

Going to the fosgate amp at 1000 watts should be about 6db louder on those subs. you may fall back in love with them!!

Just make sure you use the subsonic crossover correctly. In other words, use it!!! Helps protect your subs by keeping the stuff playing that is below tuning of the box
post #16 of 19
Thread Starter 
So I picked up the 1000 watt Rockford amp and I have it plugged in and everything. I had the gain up all the way (It wasn't even hitting as hard as my other amp without it up) and I got back from pounding 3 songs, opened the trunk, and I saw smoke coming from the port on my box. I decided to turn the gain down 1/4th of the way and see how it is. I turned the bass boost on my deck from level 2 to off due to the amp being bigger BEFORE the smoking. For the sake of smoke, I turned it back on to level 2 in order for it to still pound without having the gain all the way up.

You said something about the subsonic filter, but I have no idea how to use it. I am figuring the reason for the smoking is because of the voice coil which is trying to hit to low of notes and it can't correctly so it's heating up to the max and is melting the material, is this correct? OBVIOUSLY smoke is NEVER a good thing, and the subwoofers are still playing with no popping. How can I make sure I have the subsonic filtering set up correctly? How can I make sure I won't get smoking while driving around while having the amp and subs as loud and as powerful as they can go?

This might be a myth, but some friends told me I should never have the Bass Adjustment on my stereo deck higher than a Zero. Is this true? I am still messing with the options on the stereo deck to make sure I don't roast my subwoofers, but how can I be 100% sure I am doing no damage to the poor things. They are A LOT louder, but when I do notice them being louder, I start smelling stuff and I lower it down a significant amount to make sure no harm is or was being done. PARANOID OVER HERE!
Edited by iBlackSunday - 1/17/13 at 9:59pm
post #17 of 19
Smoke and that burning smell means you are putting to much power to those subs. Careful. You have started burning off the material they coat the voice oil or the glue that hold the coil to the former. Neither of which is good. Make sure the polarity of the subs is correct. I like to twist the positives together and negatives together and use a battery to confirm the subs are wired correct. If one woofer goes out and one goes in, the subs are out of phase. This could be the reason they are not loud sounding with a thousand watts.
post #18 of 19
Thread Starter 
How would I check to see if the subwoofers are wired correctly with a battery? Personally after taking the subwoofers out of the box and checking the cords, they were right, so I figured I would just hook them up like how they were with the other amp. Now the only thing I am having a problem with is how do I know when a certain amount of power is enough without seeing or smelling smoke? I mean, I want to pump as much power to these subs as possible without blowing them. I plan on selling them rather soon here so it will be easier to buy the new audio setup, but then with those subwoofers, how will I know if I am putting to much power to them and make sure I don't blow my new ones. So much paranoia.

As posted above (You might have not seen it because I edited it fairly soon).

This might be a myth, but some friends told me I should never have the Bass Level on my stereo deck higher than a Zero. Is this true? I also usually have my Subwoofer level at +15 because if it's any lower, I have to turn the gain on the amp up higher to compensate, which causes max gain output for the amp, which I figured was bad. I am still messing with the options on the stereo deck to make sure I don't roast my subwoofers. Is there a certain item I can use to make sure I am putting the right amount of power to the subwoofers. I liked how with my 800 watt amp, I could tell when a certain level was to high because of slight crackles in the subwoofer. Turn it down till it stops and bingo. I'm not getting any of that, just a smell and once visual smoke.
post #19 of 19
Gain does not make your amp play louder. Your amp can only put out a certain amount of power. The gain is what allows you to match the head unit's rca preout voltage.

As you turn up the volume on your head unit, the rca's outs send the music signal to the amp. this voltage is increased in the amplifier. this happens until the amp max's its power capacity.

IF you max the amp gain, your amp maxs output at like a quarter of the head unit volume. Not good. It does not get louder and then your amp starts to clip and sounds like ass.

http://www.techguys.ca/howto/speaker.html


Now your sub level control at the headunit just increases the voltage of the subwoofer RCA. Couple that with max gain and you are throwing the max power of the amp with clipping at your subwoofers. So max heat as well. IF your subs are not designed to handle it, you will smoke them

and possibly the amp if a coil melts and shorts... It's not pretty.

Here is what I tell guys when they are wanting incredibly loud bass.

Pay for a good box design and as big of a sub as you can fit. Multiple subs are great because it spreads the power over multiple motors (coil magnet of the sub).

If it's still not loud enough, all it takes is money to get louder. If money is an issue, be happy with what you have. AND save up for what you want.

I use my son as an example because he is/was the typical kid that wanted tons of bass.

He turned 16
we set up a 1000 watt Sundown amp on 4 eight inch subs. 80 watt per channel X4 channel on everything else. He did a very respectable 139db at the local car audio shows.

He changed cars due to an accident
Now he bought a Buick park avenue
sold his 8's bought four 10s
same sub amp
It was pushing a 142 with the change of sub sizes

He graduated high school
I got him 2 1500 watt sub amps (JBL GTO14001)
told him to run just one of them because his electrical was not going to cut it
2 replacement alternators and 3 battery's later because he waould not listen, he finally came to me for help
the electrical needs of those amps would literally kill his car. voltage drop would hit 9 volts
So he had to spend money on a high output alternator and 2 extra batteries in the trunk.
he swapped to 2 twelve inch subs and metered a 149
He can jam all day. We did install a battery tender in his car so he plugs it in at night and keeps all three batteries fully charged. Which helps in the winter a lot!!

AND now its a new car...
I found some old pics from the install a couple of years ago
Stereo016.jpg 174k .jpg file MattStereo005.jpg 149k .jpg file Stereo009.jpg 175k .jpg file Stereo023.jpg 102k .jpg file 07.png 186k .png file MattStereo022.jpg 79k .jpg file
Edited by cubdenno - 1/18/13 at 8:35am
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