car audio

[honda450rider33]

i need some help regarding amplifiers. i know a little about car stereo but not a whole lot i just installed 2 12" sony xplod subwoofers and i was looking into an amp the speakers are rated at 800W that is what it says on the bottom of them if i were to get an amp do i have to get a 1600w+ amp to power them both properly? any help would be greatly appreciated thanks.

[mineralgrey01gt]

is it 800w RMS? Just to let you know that an amp that says 1600w doesnt mean that its going to push that much watts. Amps that push 1600 true watts are extremely expensive. I have one thats pushing about 1000 true watts and it cost me $650. You dont need an amp to push the full power of the subs. If you do have an amp that pushes that much power, then its a definite possibility that you will blow the subs. If you have a very well built box, you can put a 50watt amp on them 2 12's and it would slam. I know a guy with 2 15's in a car with a 50watt amp and it straight slams!

[atvRiDa400ex]

Originally posted by mineralgrey01gt
I know a guy with 2 15's in a car with a 50watt amp and it straight slams!

now thats hard to believe. he has to have some other sort of power source other than that one 50w amp...

[wilkin250r]

First off, you need to know the difference between Peak power and RMS power.

Most subs are rated for Peak power, because it's a maximum. Exceeding peak power can damage the sub, but under-powering carries no danger.

Most amps are rated for RMS power (Which is usually about half of what the peak power is). RMS is basically the average overall power output. The peak power is only at a certain frequency, for a brief period of time. The RMS power is the overall average across the whole music range, where your amp will actually be operating.



But to answer your question, 800W is probably a peak power. You can power it with much less, and still get good sound quality. Something small like 20W probably isn't enough to actually push them properly, but you can certainly get good sound with something as small as 100W RMS (per speaker), but I would suggest at least 200W RMS (per speaker) to get a good thump.

[mineralgrey01gt]

nope, its specifically how the box was designed on the inside, its a crazy design. The 15's dont require a lot of power either, in fact i think they are less than my 1 audiobahn high excursion 12" sub which is 700rms.

[m_townsgreatest]

if u get an 800watt 2 channel amp and hook it up, itll be fine. its a good idea to get a capacitor so ur battery doesnt go dead also. Or you could get a 400watt 2 channel amp and cross it over and itll put out enuff to make ur subs pound great!

[Regular_Joe]

Those speakers slamming on 50 watts is totally believable. Power to volume is a logrithmic relatioinship. The louder you wanna go, you need exponentially more power.

Overall this comes down to speaker sensitivity. This is a measure of how loud a speaker CAN get w/ a certain amount of power. Most have ratings like 89db w/ 1 watt @ 1 meter. What this means is in perfect conditions the speaker will be 89db loud if your one meter away when fed 1 watt of power. So w/ that info you can constuct a theoretical volume vs power chart. Also, FYI, it takes double the power to get a 3db increase in volume.

1 watt = 89db
2 watts = 92db
4 watts = 95db
8 watts = 97db
16 watts = 100db
32 watts = 103db
64 watts = 106db
128 watts = 109db
256 watts = 112db
512 watts = 115db
1024 watts = 118db

Its easy to see that just because a speakers can handle 1,000 watts of power .... it doesn't need anywhere near that to get pretty loud.

[honda450rider33]

ok i will do some research on it. have you heard of some thing called bridging where you cross the negative wires on the subs? a friend was trying to explain it to me

[m_townsgreatest]

yes, thats what i meant not crossover. all you do to bridge it is take the negative wire from one sub and the positive wire from the other sub and run them into the same speaker set connections. like u have speaker 1 and speaker 2 and amp connection 1 and amp connection 2. You take the positive wire from speaker on and the negative from speaker 2 and run them into amp connection 1. then do the same with the other side. Thats all bridging is.

[mineralgrey01gt]

yea, also bridge the amp, most amps now-adays have how to bridge the amp on the amp itself

[wilkin250r]

You need to make sure your amp is designed to be bridged. It's pretty common nowadays, but it's not universal. You need to check the specs.

[whiteboycustom]

dont forget u can also run the subs in series or parallel, and the way i see it u can buy a big nice amp that has 800 watts but u dont have to crank it all the way up and use the max output of the amp

[cbrooks118]

50 watts wouldnt power any 15" sub on the market today. Minimum i have seen needs at least 200watts RMS. Just because you threw in an equation doesnt make you smart. If that was the case, why would they sell amps, most decks are rated 45 wt rms

that is, unless you are buying subwoofers from AutoZone....

I have two memphis 10's , that go from 200rms-800 peak, runnning off a 800wt 2 channel kenwood excelon amp. They hit good for 10's and arent even being pushed to their limit.

my advice, go to a reputable shop, they will know what you need. Dont ever get advice from the morons who work at Best Buy or Circuit City.

[Regular_Joe]

cbrooks118, please don't attack me and discredit what I am saying unless you really know that I am wrong. The truth is I doubt 100% you have ever tried powering a set of 15's on a 50 watt amp.

The problem w/ deck power is not all watts are created equal.

HU:
50 watts
5%THD
50Hz-20kHz

Amp:
50 watts
0.05% THD
20Hz-20kHz

An aftermarket amp will extend lower into the bass region while doing it with about 100x less distortion. If you rated the HU to the same specs and THD you'd be lucky to have even 10 watts of real power. Likewise if the amp got to go by the HU specs we could probably call it a 400 watt amp. FYI, these HU specs are from a Pioneer 7000 series which is a very good HU.

Most of the population doesn't understand how amplifiers and speakers really work. The max is the amount of power the speaker CAN handle in short bursts. The RMS is the amount of power the speaker CAN handle continuously. But the reality is the power output to the speaker is usually much much less. I run into people all the time that think the RMS or continuous power really is continuous and that the amp is actually feeding the speaker that much power all the time. This couldn't be more wrong. The actual power is dertermined from a combination of the volume knob and the music being played at that instant. It is constantly changing.

Minimum i have seen needs at least 200watts RMS.
This is where you are wrong. It isn't needs 200 rms .... the correct term is can handle 200 rms.

Go to a high end stereo shop that sells McIntosh stuff. Find an amp that has power meters on it. It can be a 200 watt per channel amp. The readings will be like:

0.0 watts
0.05 watts
0.10 watts
0.50 watts
1.00 watts
10.0 watts
100 watts
200 watts

You will see the meter will focus on the lower power range. This is because most of the time the actual power output is in the 0-10 watt range. Only under extreme volumes w/ extreme peaks will the amp get into the 100 and 200 watt range.

I am not just pulling numbers and formulas out of my butt here. Its how these things really work.

[cbrooks118]

i'll believe it when i hear it.

Macintosh is definetly a high end product.

thats all i have to say about that

[Regular_Joe]

A little fun fact about McIntosh. Everyone thinks they are so great and their amps are so much better and powerful than others out there. Their trick is they have super low distortion and generally have 3db of dynamic headroom. If you go back to my previous post about what it takes to get 3db you'll quickly see that means double the power. So if you see a 200 watt amp w/ 3db of dynamic headroom its really more like a 400 watt amp ...... no wonder they sound so good .....

[derekhonda]

I have a question. Why is my 500 watt JL amp making my lights dim on a hit? I didn't instal a cap, I guess I should have, but for a high powered battery and a 2 year old alternator i didn't think I would need it...

Can anyone trouble shoot that for me?

[Regular_Joe]

The amp is pulling enough current that the overall voltage in the car is dipping low. So if you meter it your likely at 13v running and 9v when the bass hits. Capacitors are a bandaid for the real problem.

First upgrade the "Big 3" for sure. Possibly the amp power and ground wire as well. What car and what size power and ground wires are you using?

BIG 3 (http://www.the12volt.com/installbay/forum_posts.asp?TID=73496&PN=1)

Since this question comes up again and again here, I thought this might be a useful post. Performing a "Big 3" upgrade on your vehicle is one way to improve the electrical system performance and its ability to supply power to your audio system. This upgrade will help any vehicle using an after-market amplified stereo system, and most certainly should be performed on any vehicle after a high-output alternator is installed.

Please be sure you read and understand this entire instruction before you begin.

Definition: the "Big Three" upgrade means improving the current capacity of three cables: 1) alternator positive to battery positive, 2) battery negative to chassis, and 3) engine ground to chassis. Some people replace the factory wiring; others add additional cables to the factory wiring. This instruction is to add cables to existing OEM wiring.

Parts and Tools:

As a minimum, you will need to purchase the following:

� Sufficient length of high-strand count high capacity power cable.
- The length required differs for every vehicle. You can measure the length of the existing cables and buy the same length, or contact your dealer or a mechanic and ask, or sometimes you can look it up in a manufacturer's wiring book, or guess. If you guess, make sure you over-estimate and buy too much.
- High strand count cable is more flexible and more reliable than low-strand count cable. Never use solid-core wire in a moving vehicle as it will eventually break.
- The gauge of wire you need depends on the total current draw of your audio system, and/or the current generating capacity of your alternator. Never use smaller cable that you used to power your amps; never use smaller cable than what already exists in your vehicle; never use smaller cable than the generating capacity of your alternator; never use smaller than 4 AWG (it's just not worth the time to use anything smaller); if in doubt, always use higher gauge cable than you think you need. If you look at the Power and Ground charts and your amplifier current draw corresponds to 2 AWG cable, use no smaller than 2 AWG cable, and use 1/0 if you can.

� 6 ring terminals or lugs of the appropriate size for the cable chosen. Two of these need to be large enough to fit over your battery posts, or appropriately sized to bolt onto your existing battery terminals.
� 1/2" or 5/8" shrink tubing (or some other form of permanent electrical insulation. Tape is NOT recommended.)
� Cable ties (plastic zip ties.)

� Wire cutters large enough to handle the cable you choose.
� Crimpers large enough to handle the connectors you choose.
� Soldering iron or gun.
� Solder.
� Scotch brite and/or a small wire brush.
� Heat gun.
� Safety razor blade (or other tool for stripping cable).
� Heat gun (if using shrink tubing).
� Wrenches for removing bolts in your vehicle.

Procedure:

1. Make sure your engine is completely cool before beginning. Identify the three cables being replaced. Make sure you can reach both ends of all cables. NOTE: the engine block to chassis cable may be between the engine and the transmission, or connected to the transmission and the fire wall, and is often an un-insulated flat braid cable.

2. Determine the lengths of cable needed to reach between the three locations being upgraded. Be sure you measure with a flexible tape (a tape measure used for sewing works great) and record the total length along the path you intend to install the cable. You do not want your cables to be pulled tight between any two locations as things move and vibrate as you drive. Be sure to include at least 1 inch extra for slack. NOTE: there is no reason to copy the existing wiring layout in your vehicle unless you want to. Also, be sure that the path you choose does not follow or lay across anything that gets hot, like exhaust parts, or anything that must move, like throttle linkage.

3. Cut your new cable to the three proper lengths. NOTE: some people like to use red cable for positive and black cable for negative. Doing this is completely up to you and is nice, but not necessary. You can use cable with any color insulation you like.

4. Strip each end of all cables to the proper length for the terminal lugs being used. NOTE: after full insertion into the lug, a small "band" of bare wire is usually seen between the back of the lug and the beginning of the cable insulation.

5. Begin at any one end and insert the stripped cable into the lug. Make sure it is fully inserted. Crimp the connector to hold the wire in place. NOTE: crimping large cable can be difficult. The intention here is not to make the crimp the sole means of holding the wire, but only to make sure the lug does not slip around during the soldering phase. I do NOT recommend using hammers or pliers or vices to crimp the connector as over-crimping can break the strands of the cable, reducing the current carrying capacity. Do not over-crimp.

6. You may need to use a vise or some other set of "helping hands" to hold the cable while you solder it. Heat your soldering iron and place it on the connector (on the lug side) barrel. Hold a piece of solder against the tip of the iron and melt the solder into the strands of the cable. Use sufficient solder to fill the connector and completely cover all strands of the cable. NOTE: the lug will get hot and will burn you if you try to hold it. Also, if the insulation on the cable starts to melt, you are over-heating the cable and not paying attention to melting the solder into the cable. You do not need to try and melt the cable!

7. Repeat the above steps on each end of all three cables.

8. After the cables have completely cooled, cut a piece of shrink tubing long enough to cover the soldered barrel end of the lugs and reach about 1/2" onto the insulation of each cable end. Slide this over each lug and use a heat gun to recover the tubing in place.

9. Disconnect your battery, starting with the negative cable first then the positive cable. Discharge any caps you may have in the system.

10. Begin adding your new cables along side the existing ones. I usually begin with the alternator positive cable. Locate the output stud on your alternator and remove the nut. Slip the new cable onto the lug and replace the nut. There is no need to disturb the existing cabling. Route the new cable to the battery and position it to connect to the positive battery post (or connect it to the positive terminal on the OEM wiring) but do not connect the battery yet.

11. Secure the new cable in place by using cable ties every 6 to 8 inches. Secure the cable to cool non-moving parts!

12. Locate where the negative battery cable attaches to the vehicle chassis. Remove this bolt and the OEM battery cable, and clean the mounting area of the chassis using scotch brite and/or a wire brush. Make sure there is no dirt, rust, paint, undercoating, etc in this location. You want bright shiny metal. Connect both your new ground and the OEM ground back to the chassis. NOTE: Some people like to create a new ground location by drilling into the chassis and using a bolt with star lock washers for the new ground cable. Route this new cable back to the battery and position it to be attached, or connect it to the negative terminal. Do not reconnect the battery yet.

13. Secure the negative cable using cable ties every 6-8 inches. Again, don't tie it to anything that moves or that gets hot!

14. Disconnect the engine ground strap at both ends. Using the wire brush or scotch brite, clean both the engine block and the chassis as you did for the first ground strap.

15. Line up the lugs on both the OEM ground strap and your new ground cable, and use cable ties to secure them to each other. This is much easier to accomplish in your lap or on the floor than it is while lying under your car or hanging upside down in the engine compartment. Reinstall both cables at the same time using the factory bolts.

16. Double check to make sure all bolts are tight. Be careful not to over-tighten them as you don't want to strip anything! Also, on some factory alternators it is WAY too easy to twist off the positive output lug. If you break it off, well hell, you really wanted a high-output alternator anyway, right? It is also a good idea at this point to measure resistance of the new cables. Take an ohm reading between the battery end of the new ground cable and the engine block. It should read less than one ohm. Also check between the alternator bolt and the disconnected positive battery terminal, which should also be less than one ohm. If you read too high resistance, double check all connections and make sure you do not have something c**ked sideways or hanging loose.

NOTE: Realize that the "absolute ground" of the electrical system is not the battery negative terminal or the vehicle chassis, but is the case of the alternator itself. This is why perhaps the most important cable among the Big 3 is the engine ground strap, as this is what connects the alternator ground to the vehicle's chassis. Be certain the resistance between the alternator case (the engine block assuming the alternator is properly bolted to the engine) and the battery negative is minimized. (Thanks to the12volt for pointing this out!)

17. When you are sure you are done and anything in your system that you may have disconnected are re-connected, clean your battery posts and reconnect the positive battery terminal first, then the negative one.

18. Start your vehicle. Hopefully the engine starts. :) Examine the engine compartment and make sure none of your cables are getting hot or are vibrating or shaking around. If they are vibrating too much you may need to relocate them or use more cable ties. If you see smoke, immediately shut off the car and disconnect the battery. Seek help. :)

19. Assuming all looks good, take a voltage reading at your amplifier and ensure you read 13.8 (or higher) volts. This indicates a properly operating charging system.

20. Now'd be a good time to turn it on and make sure it sounds good! Then of course log onto the12volt.com and post that you have upgraded your Big 3!

[whiteboycustom]

u could have a grounding issue, check all your grounds, what size power and ground wire did you use?and high power battery what does that mean? u need a deep cycle battery and it doesn't hurt to have a higher output alternator....and it doesn't hurt to have a battery cap either but thats not the solution for dimming lights


edit: he beat me to it!!!

[derekhonda]

I used the JL wiring kit, damn thing was like $100 bucks, think its 2 gauge, might be 4, they are big. The kti looks like this but they make both so id have to go check later http://cgi.ebay.com/JL-AUDIO-XB-PCS2-2-GAUGE-AMPLIFIER-INSTALLATION-CAR-KIT_W0QQitemZ300149381750QQcmdZViewItem

Anyways its an 05 Avalanche. By high output I was going by cca, i don't know what high or low is on that aspect, its about 150cca bigger than the battery i had in my dodge with a system (that didnt dim the lights)

Edit: I have it grounded to a big seat bracket bolt that goes to the frame.

[TRX_450]

Originally posted by derekhonda
I used the JL wiring kit, damn thing was like $100 bucks, think its 2 gauge, might be 4, they are big. The kti looks like this but they make both so id have to go check later http://cgi.ebay.com/JL-AUDIO-XB-PCS2-2-GAUGE-AMPLIFIER-INSTALLATION-CAR-KIT_W0QQitemZ300149381750QQcmdZViewItem

Anyways its an 05 Avalanche. By high output I was going by cca, i don't know what high or low is on that aspect, its about 150cca bigger than the battery i had in my dodge with a system (that didnt dim the lights)

Edit: I have it grounded to a big seat bracket bolt that goes to the frame.


get on ebay and buy a rockford cap...there so cheap on there and work great

[project400ex19]

Originally posted by derekhonda
I used the JL wiring kit, damn thing was like $100 bucks, think its 2 gauge, might be 4, they are big. The kti looks like this but they make both so id have to go check later http://cgi.ebay.com/JL-AUDIO-XB-PCS2-2-GAUGE-AMPLIFIER-INSTALLATION-CAR-KIT_W0QQitemZ300149381750QQcmdZViewItem

Anyways its an 05 Avalanche. By high output I was going by cca, i don't know what high or low is on that aspect, its about 150cca bigger than the battery i had in my dodge with a system (that didnt dim the lights)

Edit: I have it grounded to a big seat bracket bolt that goes to the frame.

make sure the grounding surface is completely clean of all paint. Try getting a smaller pully for your alternator. An Auto Electrician who rebuilds starters and alternators could help you there. otherwise get a cap. Or you could give me your amp...I'll let my headlights flash :p

[mineralgrey01gt]

rockford caps are very good for the price, i had one and loved it, I need to get me another

[72 chevelle ss]

Sell the Xplodes and get something that is actually decent. You probably paid what, $60 for each one? You could have put that tworads a much better sub. A good singe will sounds tons better then 2 crappy ones.

[mineralgrey01gt]

www.audiosavings.com i bought 1 audiobahn high excursion 12" sub from there for $116 shipped. Brand new in the box, 700watts RMS and peaks at 1400watts, this one sub out hit my 2 kicker comp cvr 12's

[that slow guy]

there is some very bad advise in this topic.(not all of it is bad...big 3 and sell sony was good advise)
it seems like asking about stereos on an atv forum would make as much sense as asking the people at caraudio.com how to re-valve the shocks on your quad.

[derekhonda]

Originally posted by that slow guy
there is some very bad advise in this topic.(not all of it is bad...big 3 and sell sony was good advise)
it seems like asking about stereos on an atv forum would make as much sense as asking the people at caraudio.com how to re-valve the shocks on your quad.

A lot of people on here have other hobbies then just atvs.

Anyways, just looked up the caps, can get a 500watt for like 50 or a 1000watt for like 70, does the bigger is better theory hold true here or should I get one to match my amp?

[ZBlaster]

Originally posted by derekhonda
A lot of people on here have other hobbies then just atvs.

Anyways, just looked up the caps, can get a 500watt for like 50 or a 1000watt for like 70, does the bigger is better theory hold true here or should I get one to match my amp?

Generally with a good capacitor you will want 1 farad for every 1,000 watts...

I personally have owned several different setups in my time and never really cared too much for caps... ive always ran a stronger alternator and an extra battery... My last setup i had 2 S12L7's off of 2 RF T10001BD's with an extra optima yellow top for the amps and an Ohio Generators alt (cant remember the size on it though, i got it used off a good friend of mine). Never had any problems that way.

[derekhonda]

Thanks.

Yeah the decision I have is I only plan on keeping this truck 7-10 more months, kind of looking for just the bandaid cure as oposed to spending 4 or 500 bucks and a day in the garage hooking stuff up. So a .5 farad 500 watt cap would do the trick?

[derekhonda]

Thanks.

Yeah the decision I have is I only plan on keeping this truck 7-10 more months, kind of looking for just the bandaid cure as oposed to spending 4 or 500 bucks and a day in the garage hooking stuff up. So a .5 farad 500 watt cap would do the trick?

[derekhonda]

Thanks.

Yeah the decision I have is I only plan on keeping this truck 7-10 more months, kind of looking for just the bandaid cure as oposed to spending 4 or 500 bucks and a day in the garage hooking stuff up. So a .5 farad 500 watt cap would do the trick?

[wilkin250r]

Originally posted by that slow guy
it seems like asking about stereos on an atv forum would make as much sense as asking the people at caraudio.com how to re-valve the shocks on your quad.

Not all of us is dumb ignorant rednecks, thanks.



For those that don't care for capacitors, can you give me a reason? I've played with a lot of electronics in my day, and a capacitor seems like the perfect solution to dimming headlights.

[whiteboycustom]

4-infinity 12's
1-mtx8001d amp
1-1farad cap
1-deep cycle/starting optima
1-200 amp alt.
2 gauge power and ground wire
1-alpine 9835 head unit
2-6.5" infinity kappa door speakers
2-5"x7" infinity kappa rear speakers

if i crank it up to where i cant stand it my lights will dim just alittle not like strobes in a cop car though

get a 2-channel amp about 400watts and be done with it, do you think u can set and adjust the amp?i cant recall but what type of box do you have the 12's in? ported box,sealed box, bandpass box? what type of music do u listen to? can your high ends over power the subs? maybe a 4 channel amp and run your subs and highs for better quality

this is a pic of my box in my ranger, 4 -12's down firing
http://i40.photobucket.com/albums/e238/whiteboycustom/untitled1.jpg

[Regular_Joe]

Most any car can handle the current demand for about 1k watts pretty reliably w/o any major noticable dimming. You can get a cap to help, but chances are there is something else wrong.

[TGW_400ex]

Originally posted by mineralgrey01gt
is it 800w RMS? Just to let you know that an amp that says 1600w doesnt mean that its going to push that much watts. Amps that push 1600 true watts are extremely expensive. I have one thats pushing about 1000 true watts and it cost me $650. You dont need an amp to push the full power of the subs. If you do have an amp that pushes that much power, then its a definite possibility that you will blow the subs. If you have a very well built box, you can put a 50watt amp on them 2 12's and it would slam. I know a guy with 2 15's in a car with a 50watt amp and it straight slams!

Thats not humanly possible.

[72 chevelle ss]

Caps are just a cheap fix. And with the small system you are planning on running, you won't need one. If you start getting upwards of 1500 watts, do big 3, better battery, and possibly HO alt.