have head unit, highs, mids and lows...must I have an amp?

chadpadams
chadpadams Posts: 13
edited June 2009 in Car Audio & Electronics
I drive a 2003 Jeep Liberty, the speakers have blown out so I was lucky enough to get to buy a whole new system (BLESSING in disguise).

So I purchased 4 Polk db6501s that come with tweeters and passive crossovers.

The head unit i got was a pioneer DEH-P4100UB
http://www.pioneerelectronics.com/PU...rs/DEH-P4100UB

I originally bought this head unit b/c i thought i wouldn't "have to buy an amp" to drive the speakers and my sub (I have a JL W0 12" in a sealed box that i will also use.)
but once i did further research everyone seems to think otherwise.
I don't really have the $ to buy much else...but if the speakers will be damaged, i might just have to break down.

Question 1: do i need to use the crossovers that came with the speakers?
seems like the head unit has one that is active...is that sufficient?

Question 2: do i need to buy an amp to power these speakers to prevent damage from too little power?

Question 3: if i do need to buy an amp can i just get 1 to push the speakers and the sub or do i need one for the high and mid and one for the low?
and if i do need an amp, what brands should i consider? keeping it cheaper price-wise?

Question 4: if i must install an amp, how do i do this? and where do i put it...
i think i will have no trouble with the head unit and speakers, but i have no idea how to set up an amp...

i am a musician, so i am concerned about high quality sound and have a pretty good ear, but this is the first time i have dealt with buying a whole new system for a car...

thanks in advance for any help/advice!
Post edited by chadpadams on

Comments

  • dirthog
    dirthog Posts: 124
    edited June 2009
    chadpadams wrote: »
    I drive a 2003 Jeep Liberty, the speakers have blown out so I was lucky enough to get to buy a whole new system (BLESSING in disguise).

    So I purchased 4 Polk db6501s that come with tweeters and passive crossovers.

    The head unit i got was a pioneer DEH-P4100UB
    http://www.pioneerelectronics.com/PU...rs/DEH-P4100UB

    I originally bought this head unit b/c i thought i wouldn't "have to buy an amp" to drive the speakers and my sub (I have a JL W0 12" in a sealed box that i will also use.)
    but once i did further research everyone seems to think otherwise.
    I don't really have the $ to buy much else...but if the speakers will be damaged, i might just have to break down.

    Question 1: do i need to use the crossovers that came with the speakers?
    seems like the head unit has one that is active...is that sufficient?

    I would say active is out since you are going to run four speakers and your deck isn't capable.

    Question 2: do i need to buy an amp to power these speakers to prevent damage from too little power?

    Imposable to damage a speaker because of too little power. It is OK to run the Polk's off the head unit, but will sound better and get louder with an amp. The JL sub will need to be amped.

    Question 3: if i do need to buy an amp can i just get 1 to push the speakers and the sub or do i need one for the high and mid and one for the low?
    and if i do need an amp, what brands should i consider? keeping it cheaper price-wise?

    You could get a four channel amp to run the speakers and 1 for the sub. Some amps will have five channels, four for speakers and one for sub. Do a little research to find what you like for the price and we can help more.

    Question 4: if i must install an amp, how do i do this? and where do i put it...
    i think i will have no trouble with the head unit and speakers, but i have no idea how to set up an amp...

    Easier if someone had an amp in front of you to explain everything and be able to point out the different connections. If you purchase an amp there should be directions on how to connect it and any further questions would be easier to answer for you.

    i am a musician, so i am concerned about high quality sound and have a pretty good ear, but this is the first time i have dealt with buying a whole new system for a car...

    thanks in advance for any help/advice!

    If you are truly committed to getting the best sound quality I would suggest ditching the 2 rear speakers and run just the fronts off the passive crossovers. Later on after getting a better feel and doing a little research, bi-amp the passives and after that take the plung into the active world.
    HU: 880PRS
    Front: SR6500
    Amp: Alpine MRV-F545
    Sub: SR124-DVC
    Amp: Alpine MRD-M1005
  • nguyendot
    nguyendot Posts: 3,594
    edited June 2009
    No head unit is going to power speakers at their full potential. That head unit probably has a 10a breaker and it probably consumes about half of that with the other half going to power the amp @ 50-60% efficiency. 5A x 14.4v = 72 watts. This is just an example but gives you a good idea of how much power your head unit really puts out.

    You NEED an amp. No head unit is going to power speakers, or a subwoofer correctly.

    1) yes you need the crossover. The head unit crossover only separates high from low, your speakers need to separate the highs into tweeter and midrange. In order to only use an electronic crossover you'd have to have a much much more complicated setup with more dedicated amplifiers. If you run the speakers without their crossover, where will you plug the extra set of leads in?

    2) Yes. Not just to prevent damage, but for better sound quality. You will never get the full range of sound without more power than what your head unit can provide.

    3) yes you can get amps that have 5 channels - 4 for your speakers and 1 for your sub. Most people get 2 separate amps, a 4 channel for the mid/highs and a dedicated bass amp.

    4) If you haven't hooked one up before, ask a friend, do your research, and get the right stuff to do it with. It's generally very easy - all you have to do is run power and signal to the amp, and from the amp you run speaker wire.
    Main Surround -
    Epson 8350 Projector/ Elite Screens 120" / Pioneer Elite SC-35 / Sunfire Signature / Focal Chorus 716s / Focal Chorus CC / Polk MC80 / Polk PSW150 sub

    Bedroom - Sharp Aquos 70" 650 / Pioneer SC-1222k / Polk RT-55 / Polk CS-250

    Den - Rotel RSP-1068 / Threshold CAS-2 / Boston VR-M60 / BDP-05FD
  • nguyendot
    nguyendot Posts: 3,594
    edited June 2009
    "Question 2: do i need to buy an amp to power these speakers to prevent damage from too little power?

    Imposable to damage a speaker because of too little power. It is OK to run the Polk's off the head unit, but will sound better and get louder with an amp. The JL sub will need to be amped.
    "


    You're kidding, right? Impossible to damage because of too little power? It's 100x more likely to damage a speaker with too little power than too much power.
    Main Surround -
    Epson 8350 Projector/ Elite Screens 120" / Pioneer Elite SC-35 / Sunfire Signature / Focal Chorus 716s / Focal Chorus CC / Polk MC80 / Polk PSW150 sub

    Bedroom - Sharp Aquos 70" 650 / Pioneer SC-1222k / Polk RT-55 / Polk CS-250

    Den - Rotel RSP-1068 / Threshold CAS-2 / Boston VR-M60 / BDP-05FD
  • chadpadams
    chadpadams Posts: 13
    edited June 2009
    thank you for your response, and please excuse my ignorance.

    you say the deck isn't capable? The specs say it has 5 channels: 22wattsx4 RMS and then 1 additional channel for the sub....is that not correct?
    the spec also say that there is a low and high pass crossover. doesn't this mean i wouldn't need the passive one that came with the speakers?

    and as far as damaging the speakers from too little power, i read somewhere that if you have too little power running to the speakers something results in distortion that will damage the speakers...anyway, it seemed counter-intuitive to me and didn't make sense, so maybe they were just flat out wrong.

    and yes, i have 4 speakers, but don't have to use 4. I just thought i needed some speakers in the backseat too.

    thanks again for your help!
  • chadpadams
    chadpadams Posts: 13
    edited June 2009
    thank you both, nguyendot and dirthog.
    I wrote my last post before i read nguyendot's reply, so thanks for the suggestions and disregard my last post is now moot.

    Thanks again!
  • nguyendot
    nguyendot Posts: 3,594
    edited June 2009
    Trust me, you need the crossovers with the speakers. As you learn more and want to be more involved and get a more sophisticated setup with active crossovers and discrete amplifiers you will be able to run without a crossover. At this point since you have not yet learned that and it would be very difficult especially since you do not have the correct equipment I would suggest you run them with the included crossover. I think you will like the sound anyways.
    Main Surround -
    Epson 8350 Projector/ Elite Screens 120" / Pioneer Elite SC-35 / Sunfire Signature / Focal Chorus 716s / Focal Chorus CC / Polk MC80 / Polk PSW150 sub

    Bedroom - Sharp Aquos 70" 650 / Pioneer SC-1222k / Polk RT-55 / Polk CS-250

    Den - Rotel RSP-1068 / Threshold CAS-2 / Boston VR-M60 / BDP-05FD
  • dirthog
    dirthog Posts: 124
    edited June 2009
    nguyendot wrote: »
    "Question 2: do i need to buy an amp to power these speakers to prevent damage from too little power?

    Imposable to damage a speaker because of too little power. It is OK to run the Polk's off the head unit, but will sound better and get louder with an amp. The JL sub will need to be amped.
    "


    You're kidding, right? Impossible to damage because of too little power? It's 100x more likely to damage a speaker with too little power than too much power.

    Please explain how it's 100x easier to you blow a speaker from too little power?

    Do a test for me, hook up one of your tweeters with 1 watt and another with 100 watts and tell me which one has damage first.

    OR set you Hu at the lowest volume and tell me how long your speakers will play, how about forever. But this isn't possible because your speakers aren't getting enough power, THEY MUST HAVE DAMAGE!:D

    nguyendot wrote: »
    Trust me, you need the crossovers with the speakers. As you learn more and want to be more involved and get a more sophisticated setup with active crossovers and discrete amplifiers you will be able to run without a crossover. At this point since you have not yet learned that and it would be very difficult especially since you do not have the correct equipment I would suggest you run them with the included crossover. I think you will like the sound anyways.

    Unless you purchase more equipment and research active setups you have to use the passive crossovers.
    HU: 880PRS
    Front: SR6500
    Amp: Alpine MRV-F545
    Sub: SR124-DVC
    Amp: Alpine MRD-M1005
  • nguyendot
    nguyendot Posts: 3,594
    edited June 2009
    One word: clipping.

    Do some more research around the board and you will see it is much much easier to damage speakers with too little power.

    Now you mention volume. Volume does not equal power. We're talking about how much power output the amplifier is capable of. You can set any amplifier to a low volume. The problem is not that, it is if you do not provide enough power and you crank it, it will try to produce with power that is not available and send the amplifier into clipping, which will damage the speakers.
    Main Surround -
    Epson 8350 Projector/ Elite Screens 120" / Pioneer Elite SC-35 / Sunfire Signature / Focal Chorus 716s / Focal Chorus CC / Polk MC80 / Polk PSW150 sub

    Bedroom - Sharp Aquos 70" 650 / Pioneer SC-1222k / Polk RT-55 / Polk CS-250

    Den - Rotel RSP-1068 / Threshold CAS-2 / Boston VR-M60 / BDP-05FD
  • chadpadams
    chadpadams Posts: 13
    edited June 2009
    So...one more question for anyone willing to answer:
    my speakers (4 of them) are 100watts RMS capable with 300w max
    my sub is 125 watts RMS with 300w max.
    I am going to get an amp or 2...I would prefer to get 1, but am open to suggestions.
    I wasn't ready to spend all this money on a car stereo right now, but have gone too far to turn back. I really would like to keep it under $250 more total for amps and kits and wires. I could get rid of 2 of the db6501s, especially if y'all think it would sound better ...and then would have $350-375 to spend. or should i get some dif. speakers for the back?

    so, here are my options as i see it:
    1. buy a 5 channel amp that would power my 4 dbs and sub...any suggestions on this amp?
    2. buy a 4 channel for the speakers and 1 for the sub...any suggestions on these amps?
    3. sell 2 of the dbs and get a 3 channel amp to run the 2 dbs and the 1 sub...suggestions?
    4. sell 2 of the dbs and get a 2 channel and a 1 channel...suggestions?

    did I leave out any other options?

    thank you guys so much. I am really excited to finally have something better than the **** infinity factory stereo. I am just a poor student and can't sell the farm to get this done.
  • nguyendot
    nguyendot Posts: 3,594
    edited June 2009
    MB Quart 4 channel, 125wrms per channel : http://ikesound.com/product-product_id/8607

    MB Quart Class D - 125w@4 ohms, 250@2, 500@1 http://ikesound.com/product-product_id/8610


    I used MB Quart in the past and have been very pleased with them. Not sure on these but it should do fine. Prices arent half bad.
    Main Surround -
    Epson 8350 Projector/ Elite Screens 120" / Pioneer Elite SC-35 / Sunfire Signature / Focal Chorus 716s / Focal Chorus CC / Polk MC80 / Polk PSW150 sub

    Bedroom - Sharp Aquos 70" 650 / Pioneer SC-1222k / Polk RT-55 / Polk CS-250

    Den - Rotel RSP-1068 / Threshold CAS-2 / Boston VR-M60 / BDP-05FD
  • dirthog
    dirthog Posts: 124
    edited June 2009
    We are talking about two different things and maybe I didn't explain it well.

    You are talking about clipping, but clipping is not caused from too little power. It is caused by pushing equipment past it's limits. Hopefully the OP will have enough sense not to push his equipment that hard.

    He was hoping he could run the speakers off the Hu's power and he can.

    If I play my Hu at the lowest volume the speakers will be getting little power. My speakers will not be damaged from having too little power.

    If you don't know when your Hu starts to clip 3/4 volume is a good reference, using the Hu's power or RCA's/amp.
    HU: 880PRS
    Front: SR6500
    Amp: Alpine MRV-F545
    Sub: SR124-DVC
    Amp: Alpine MRD-M1005
  • nguyendot
    nguyendot Posts: 3,594
    edited June 2009
    He's asking if he can power his subwoofer off of it too...which he cannot.
    Main Surround -
    Epson 8350 Projector/ Elite Screens 120" / Pioneer Elite SC-35 / Sunfire Signature / Focal Chorus 716s / Focal Chorus CC / Polk MC80 / Polk PSW150 sub

    Bedroom - Sharp Aquos 70" 650 / Pioneer SC-1222k / Polk RT-55 / Polk CS-250

    Den - Rotel RSP-1068 / Threshold CAS-2 / Boston VR-M60 / BDP-05FD
  • chadpadams
    chadpadams Posts: 13
    edited June 2009
    Thanks so much for the suggestions! one last...make that 2 more questions before I take the plunge:
    125watts RMS won't hurt the polk dbs that were rated 100watts RMS?
    and I saw on ikesound how cheap the dynomat was...would it be worth it to buy the extreme door package for the front doors?
  • chadpadams
    chadpadams Posts: 13
    edited June 2009
    sorry one more: will this cause any problems with my alternator? will i need to do anything as far as protecting the car's power/battery anything i should be aware of?

    thanks again!
  • nguyendot
    nguyendot Posts: 3,594
    edited June 2009
    It can. Install it and see how it affects your car. If it uses too much power you may need to upgrade your alternator or get a deep cycle battery.

    No the extra power won't hurt anything, if anything it will help prevent clipping if you play it at a decent level.

    Dynamat is decent to help deaden your doors, firewall, floor, wheel wells, roof, etc etc. Do it if you like it, but its a big undertaking because it takes forever to put on (you have to remove your door panels etc.
    Main Surround -
    Epson 8350 Projector/ Elite Screens 120" / Pioneer Elite SC-35 / Sunfire Signature / Focal Chorus 716s / Focal Chorus CC / Polk MC80 / Polk PSW150 sub

    Bedroom - Sharp Aquos 70" 650 / Pioneer SC-1222k / Polk RT-55 / Polk CS-250

    Den - Rotel RSP-1068 / Threshold CAS-2 / Boston VR-M60 / BDP-05FD
  • chadpadams
    chadpadams Posts: 13
    edited June 2009
    thanks again!
    I just thought that if i was going to do it, it might be a good idea to do the doors while i'm putting in the speakers...since the panels will be off.
    would it be worth it to just do the doors?
  • dirthog
    dirthog Posts: 124
    edited June 2009
    I think you need to re-read my post, look at the red. So back off because we are both trying to help the guy.


    Quote:
    Originally Posted by chadpadams
    I drive a 2003 Jeep Liberty, the speakers have blown out so I was lucky enough to get to buy a whole new system (BLESSING in disguise).

    So I purchased 4 Polk db6501s that come with tweeters and passive crossovers.

    The head unit i got was a pioneer DEH-P4100UB
    http://www.pioneerelectronics.com/PU...rs/DEH-P4100UB

    I originally bought this head unit b/c i thought i wouldn't "have to buy an amp" to drive the speakers and my sub (I have a JL W0 12" in a sealed box that i will also use.)
    but once i did further research everyone seems to think otherwise.
    I don't really have the $ to buy much else...but if the speakers will be damaged, i might just have to break down.

    Question 1: do i need to use the crossovers that came with the speakers?
    seems like the head unit has one that is active...is that sufficient?

    I would say active is out since you are going to run four speakers and your deck isn't capable.

    Question 2: do i need to buy an amp to power these speakers to prevent damage from too little power?

    Imposable to damage a speaker because of too little power. It is OK to run the Polk's off the head unit, but will sound better and get louder with an amp. The JL sub will need to be amped.

    Question 3: if i do need to buy an amp can i just get 1 to push the speakers and the sub or do i need one for the high and mid and one for the low?
    and if i do need an amp, what brands should i consider? keeping it cheaper price-wise?

    You could get a four channel amp to run the speakers and 1 for the sub. Some amps will have five channels, four for speakers and one for sub. Do a little research to find what you like for the price and we can help more.

    Question 4: if i must install an amp, how do i do this? and where do i put it...
    i think i will have no trouble with the head unit and speakers, but i have no idea how to set up an amp...

    Easier if someone had an amp in front of you to explain everything and be able to point out the different connections. If you purchase an amp there should be directions on how to connect it and any further questions would be easier to answer for you.

    i am a musician, so i am concerned about high quality sound and have a pretty good ear, but this is the first time i have dealt with buying a whole new system for a car...

    thanks in advance for any help/advice!

    If you are truly committed to getting the best sound quality I would suggest ditching the 2 rear speakers and run just the fronts off the passive crossovers. Later on after getting a better feel and doing a little research, bi-amp the passives and after that take the plung into the active world.
    nguyendot wrote: »
    He's asking if he can power his subwoofer off of it too...which he cannot.
    HU: 880PRS
    Front: SR6500
    Amp: Alpine MRV-F545
    Sub: SR124-DVC
    Amp: Alpine MRD-M1005
  • cadenceclipse
    cadenceclipse Posts: 459
    edited June 2009
    yeah dynamat doors. sell 1 pair. bi-amp 1 pair off HU (front). so u only need amp for sub(s), thankfully, w/ that budget.. and u don't need to worry bout electriucal(alt, batt) yet as long as your only amping sub(w/ less than bout 600wrms depending on car(electrical(alt)]
    Polk MM6501 kick panels, Eclipse cd7200mkll and SW9122 Bomb Box, Cadence A4, A7, CAP5, JL8W3V3