Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Which amp/speaker setup? UPDATED...

Discussion in 'Audio' started by 73k5blazer, Dec 8, 2005.

  1. 73k5blazer

    73k5blazer Unplug the matrix cable from the back of your head Premium Member

    Joined:
    Dec 28, 2001
    Posts:
    4,987
    Likes Received:
    38
    Location:
    The Rustbelt
    Ok, I've got this ihead unit in my K5
    I have Polk 5.25" 2-ways in the dash (2-50w RMS), I will have 6.5's or 6x9's in the back (20-80watts RMS)seat quarter panel area, and 1 10" or 12" sub. The question is, the head unit has a decent built-in amp (the mosfet45, 22x4 RMS). It has pre-amp outs for sub, or for regular speakers. I'm not really into big booming bass sound, just want decent sound at volume when going down the road with the top off.
    Should I get 2 amps,one to run the front/rear speakers, or 1 amp to run a sub and run the 4 speakers off the head unit, or 1 amp and run the 4 speakers off it and run the sub off the head unit?
     
    Last edited: Dec 17, 2005
  2. Z3PR

    Z3PR Banned

    Joined:
    Mar 30, 2002
    Posts:
    19,217
    Likes Received:
    0
    Location:
    Everywhere
    I can turn off the inturnal amp in my headunit, run it as a deadhead. I have a Phoenix Gold 4 channel amp for the 4 main speakers, and a MMATS amp for the sub. Much cleaner sound.
     
  3. Greg72

    Greg72 "Might As Well..." Staff Member Super Moderator

    Joined:
    Mar 5, 2001
    Posts:
    15,681
    Likes Received:
    1,392
    Location:
    642 Days to BB2018
    I don't want to burst your bubble..... but the NO head unit in the world puts out the kind of power the manufacturers claim.It's been covered before, but the reality is that the deck can put out about 7 to 8 watts/channel max. It's a limitation based on the physical size of a DIN deck and the fact that you can't do the DC/AC transformers needed to get really large power numbers (like a standalone power amp has)SO....I would suggest 1 amp to get you started. Use it for the subs. Then take the other speakers and run them off your deck, BUT strip out all the bass information below maybe 60Hz...it takes a lot of power to drive low frequencies, so by stripping it out you can make things a lot easier on the deck and get better sound from it.If that still doesn't get you where you want to be sonically, you can add the second amp for your satellite speakers and ditch the deck's internal amp altogether....:usaflag:
     
  4. 73k5blazer

    73k5blazer Unplug the matrix cable from the back of your head Premium Member

    Joined:
    Dec 28, 2001
    Posts:
    4,987
    Likes Received:
    38
    Location:
    The Rustbelt
    No bursting here. This is the kinda of info I'm looking for, thanks!
    I do have a 2 year old pioneer head unit i my '86 C10 regular cab, has the same mosfet 45 thing, got 5.25" speakers up front and 2 box speakers behind the seat, it powers it good, but it's a regular cab and I have a feeling it's almost at it limit. Butl, like you say, it powers everything, so in the K5 if I take the low end duties off it, I might be ok, then again mabey not. 2 amps or 1...hmmm.....Any more suggestions.....
     
  5. Z3PR

    Z3PR Banned

    Joined:
    Mar 30, 2002
    Posts:
    19,217
    Likes Received:
    0
    Location:
    Everywhere
    There's always a 5 channel amp. The 4 main speakers + a sub.
     
  6. 73k5blazer

    73k5blazer Unplug the matrix cable from the back of your head Premium Member

    Joined:
    Dec 28, 2001
    Posts:
    4,987
    Likes Received:
    38
    Location:
    The Rustbelt
    Sweet. I didn't see those. Sorry, I'm not so car stereo savvy, last system I built was in '92. Thanks!
     
  7. Z3PR

    Z3PR Banned

    Joined:
    Mar 30, 2002
    Posts:
    19,217
    Likes Received:
    0
    Location:
    Everywhere
  8. tuffdogstudio

    tuffdogstudio 1/2 ton status

    Joined:
    Nov 1, 2004
    Posts:
    239
    Likes Received:
    0
    Location:
    New Mexico

    Do what Greg suggests. I've had a number of systems that ran 4 speakers off the deck running inline caps to block the bass and then a 1 channel amp to a 12" sub., was always a pleasurable ride.
     
  9. 73k5blazer

    73k5blazer Unplug the matrix cable from the back of your head Premium Member

    Joined:
    Dec 28, 2001
    Posts:
    4,987
    Likes Received:
    38
    Location:
    The Rustbelt
    Ok. I think I will do that. I'll amp the sub, and run the 4 mains off the deck. My head unit has a adjustable high pass filter built into it when the sub-woofer is connected to the sub pre-outs. The manual states 50-80-125, I unfortunatly think that means my only choices are 50,80 or 125. We'll see. Thanks for all the help!
     
  10. 73k5blazer

    73k5blazer Unplug the matrix cable from the back of your head Premium Member

    Joined:
    Dec 28, 2001
    Posts:
    4,987
    Likes Received:
    38
    Location:
    The Rustbelt
    Ok, another question. When sizing an amp for a sub, lets say the sub says 75-350wRMS (@ 4 ohms) peak 1400, what size amp should I be shooting for? 350 (@ 4 ohms)? Just under 350? Or down lower like 200-250 or so?
     
  11. Greg72

    Greg72 "Might As Well..." Staff Member Super Moderator

    Joined:
    Mar 5, 2001
    Posts:
    15,681
    Likes Received:
    1,392
    Location:
    642 Days to BB2018
    It's not that critical to match the amp power rating to the speakers....

    The RMS value is just a way for the speaker manufacturer to give you an idea of how much continuous power the speaker can handle without having a meltdown, but realistically "music" isn't a continuous tone. It's all quick, high powered transients anyway.

    You could run that sub with 100 watts or 1000 watts...or anything in between. The real question is if the amp is producing clean power for the speaker. If the amps is clipping or producing dirty power, that's when you'll find yourself blowing speakers. You'd be amazed how much clean power a speaker can handle.

    The other consideration is the ohm rating of the sub(s). If you are setting up the subs to create a low ohm load, make sure the amp you buy is capable of running cleanly at that load. Some amps can run cleanly at 4ohms, but are quite a bit "dirtier" at 1 or 2 ohms...
     
  12. 73k5blazer

    73k5blazer Unplug the matrix cable from the back of your head Premium Member

    Joined:
    Dec 28, 2001
    Posts:
    4,987
    Likes Received:
    38
    Location:
    The Rustbelt
    Ok, I just bought this after many hours of research.Mono amp
    and this sub
    Together with the polk 5.25 fronts, polk 6.5" and the pioneer head unit, I think this should be a pretty decent setup.
    Thanks for all the help
     
  13. chevyin

    chevyin 1/2 ton status

    Joined:
    Sep 14, 2005
    Posts:
    1,324
    Likes Received:
    0
    Location:
    Pismo Bch CA
    Most internal amplifiers in H/U's are only made by a handful of manufacturers around the world (non-proprietary). The vast majority of those internal amps max out at 18-22 watts per channel (RMS) iirc, but they sound very bad doing anywhere near that. One notable exception are the Pioneer MOSFET units. Pioneer does make (or did at least) some heads that had a mosfet amplifier built in, and they really can produce in upwards of 40watts per channel (or so Ive read from tests). But I suspect, being such a small unit, with no real coolin capacity like an external amp, its not the cleanest in the world either. Going to an external amplifier on your main speakers (fronts mainly, but front and rears for many ppl) makes all the difference in the world. Any semi-serious subwoofer system will overpower most mids and tweeters that are powered off a h/u. Its tough to get really blended output from the entire system with a setup like that. But then, some people like a system with exagerated subbass too, so to each their own. Ive seen trucks with a wall of 15's, and the the rest of the system powered off the headunit. :doah: Personally I wouldn't recommend a high powered sub, but then running your fronts off the h/u and using bass blockers. BB's are just shunts, dissipating the lost energy (from the freqs they filter out) as heat. So basically you'll already be powering the front speakers with a weak amp (h/u), and then you'll be losing more efficiency by using bassblockers. Get an external amp with a built-in xover and avoid all that mess, you'll be glad you did. Think about it, the front speakers play like 90% of the frequencies you'll hear from the stereo, why shouldn't they get the most attention when it comes to powering them, placing them, etc etc..?

    RMS value of a speaker is (generally speaking) a rating of its thermal limits. There are two basic ways to blow a speaker, thermally and mechanically. Mechanically means bottoming the speaker out, physically pushing it further than its motor and/or suspension will allow. Blowing a speaker thermally means simply pushing more current through the speaker than it is capable of handling. A speaker's voice coil is made of a certain gauge wire, and at a certain temp, it WILL melt. The speaker has cooling capabilites that combat this, but that only goes so far. Basically, if you try to push a 100watt speaker with 1000watts, it will melt down. Now that's not to say you cannot use a 1000watt amp on a 100watt speaker, but you certainly could not push the amp to its full potential without damaging the speaker. Most manufacturer's RMS ratings are based almost exclusively off of thermal limits because mechanical limits are enclosure dependant. The manufacturer doesn't know what size/type of box you will be putting the speaker in, which is a major factor in a speaker's mechanical limits, so their specs are basically thermally limits.

    This brings us to the next topic: distortion. Its a common misconception that power does not kill speakers, distortion does. I say this is a misconception because its only half true, at best. Power most certain can destroy a speaker as I described above, thermally. Distortion, in and of itself, wont hurt anything. It needs power to do damage to your speakers, let me explain. First off, Im discussing signal-source distortion at this point. When a speaker receives a signal, its in the form of a wave (as seen on an o-scope). The wave's shape, wavelength and amplitude all affect the speaker cone's motion. The wavelength of course affects the frequency. As the cone moves, it follows the motion of this wave (as seen from the side). When a piece of equipment in your signal chain distorts, it squares off the signal wave (at a given freq). When looking at it on the o-scope, the wave will not look like a rounded wave anymore, but will have a flat (think of a flat-top mesa). What this means is, as the speaker tries to reproduce this signal form, it hits this flat in the wave and stops moving (at the amplitude of the flat on the wave) and that is a very bad thing. I mentioned earlier that speakers have an ability to combat heat build-up within their motors, one major way is by pumping cool air in through the rear pole vent (that hole in the magnet) and across the voice coil, thereby cooling it. But, if you send a squared signal to the speaker, cone motion stops for a period of time each and every cycle, yet the current still passes through the speaker fully. So as you can imagine, this means heat build-up increases even more rapidly than if the speaker was being fed that much wattage, but with a non-squared wave (not distorted). The harder you clip the signal (square the wave), the longer the flat is in relation to the overall wave cycle, thus the speaker stands still longer and has more and more heat build-up.

    That being said, a squared signal wave (distortion) will hurt nothing without an excess of power (watts). To the speaker, that squared wave is just another bit of the music its suppose to reproduce (and it will faithfully). The only difference is that stopping of cone motion every cycle. If the speaker can easily handle the power going through it, even when squared, it will not burn up. For example, hook a 100watt amp to a (true) 1500watt subwoofer, and I don't care how nard you clip the amp, you will not reach the thermal limit of the speaker, period. This is why people are correct to say 'dirty' power will kill a speaker sooner, but clean power wont. But, that's also why people are wrong if/when they say distortion kills speakers rather than power.

    Lastly, a 'clipped' amplifier (one driven to distort based on incorrect input gain settings) can output (squared) power many mutiples of its rated output. So, clipping an amp can be fatal to speakers pretty easy, as it squares the signal wave (limits cone motion, thereby hurting the speaker's cooling abilities) AND it scales up the amount of current passing through the coil.
     
  14. 73k5blazer

    73k5blazer Unplug the matrix cable from the back of your head Premium Member

    Joined:
    Dec 28, 2001
    Posts:
    4,987
    Likes Received:
    38
    Location:
    The Rustbelt
    Wow, that's some great info thanks! I hear what your saying on running the main speakers from an amp as well. I still might do that. I certanly don't want to have overpowering bass. The H/U i got is a pioneer mosfet45, and is 1.5 din size (or whatever the "GM/Chrysler" size is, I think 1.5), but I suspect they didn't redesign the internal amp because they had more room. It might give it more cooling capacity at the least though. I try it out this way, if it's too much bass, I'll add an amp to power the main speakers.
     
  15. chevyin

    chevyin 1/2 ton status

    Joined:
    Sep 14, 2005
    Posts:
    1,324
    Likes Received:
    0
    Location:
    Pismo Bch CA
    Absolutely, try it out. :) Ive yet to get my hands on one of the Pioneer mosfet units, but Ive heard good things. Honestly, Id forgotten you said you had the Pioneer mosfet when I was speaking about your weak h/u amp... my bad. And, if you dont like it, you can always add the amp later. Let us know how it works out.
     
  16. 73k5blazer

    73k5blazer Unplug the matrix cable from the back of your head Premium Member

    Joined:
    Dec 28, 2001
    Posts:
    4,987
    Likes Received:
    38
    Location:
    The Rustbelt
    Was out-of-town all week. Came back to 6" of new snow (that my wife had been driving on for 3 days:doah: took me 1.5 hours to plow the driveway), and.......
    [​IMG]

    Still waiting on the sub and rear 6.5" speakers......not shown is the $40 adaptor to hook an AUX input to the Head unit. They got you comin' and going. H/U adverties "aux input", but they don't tell you you need a $40 adaptor to do it. List price is $70 :eek: eBay is my friend.
    I'm putting the CD changer under the dash accessible through the passenger side vent. I already made up the brackets for that. Center vent will have 2 lighter accessory outlets. Sat Radio is going in the flip down ashtray holder. Just need to get my buddy who good with plastics to make up some pretty bezels for the vents...
    Now if only I could find a place to mount the Sat radio antenna on this fiberglass body......
     
    Last edited: Nov 5, 2006
  17. Thunder

    Thunder 3/4 ton status

    Joined:
    Jul 20, 2000
    Posts:
    8,946
    Likes Received:
    1
    Location:
    Northeast Nevada
    I have that Pioneer HU In my K5 and love it. Works/and sounds great! Very clean sound, Never skips. It has Plenty of power for me. Just wanted to keep things simple so I dont have an amp. Just RF 6x9s in the back and pioneer 4" in the dash. Install was very easy. With the wireing adapter. It was pretty much plug and play. Have you installed yet? I think you will love it when you hear it.
     
  18. 73k5blazer

    73k5blazer Unplug the matrix cable from the back of your head Premium Member

    Joined:
    Dec 28, 2001
    Posts:
    4,987
    Likes Received:
    38
    Location:
    The Rustbelt
    Nope. Not yet. Been picking at it. Had to pull the transmission on my '97 to swap the internal slave cylinder, and have been chasing a gremlin in my DD C10. The K5 waits...for now. I'm getting there...Happy to see someone else with that HU.
     
  19. 73k5blazer

    73k5blazer Unplug the matrix cable from the back of your head Premium Member

    Joined:
    Dec 28, 2001
    Posts:
    4,987
    Likes Received:
    38
    Location:
    The Rustbelt
    Whew. This is taking forever. I got the Sub amp installed, the front door speakers, and the sub mounted. Got the holes drilled for the rear speakers, and just need to mount the 4 channel amp. All the RCA and speaker has been run through Liquidtight conduit. So I don't junk up my pretty line-x interior, at least not with wires. I need a 12" grille to cover my 10" sub. Head unit is all fitted out, just need power in the cab still though to power it up.
    I ran power to the amps with 6ga from my rear distribution center, which was wired down the from with 3/0 cable, also for winch leads to the rear.

    You can see the amp mounted inside here
    [​IMG]

    I used a piece of foam on the back of the diamond plate to seal off the remainingchunk I had to cut from the sub hole (shown above) to fit the amp in there.
    [​IMG]


    The liquid tight connections at the firewall
    [​IMG]

    The 2-gang plastic liquidtight junction box mounted on the left side, just forward of the rear tire.
    [​IMG]
     
    Last edited: Jan 15, 2007
  20. 73k5blazer

    73k5blazer Unplug the matrix cable from the back of your head Premium Member

    Joined:
    Dec 28, 2001
    Posts:
    4,987
    Likes Received:
    38
    Location:
    The Rustbelt
    It's Alive! It's Alive!

    To the dismay of my 5 year daughter, and my slumbering wife, since all the components, except the head unit, were in their final resting places, I rigged up the battery connection and set the HU on the floor and plugged her in.
    Holy cow, this system sounds downright aweesssommmeeee.
    I ended up going with Polk 6.5" rears, polk 5.25" front, polk c400.4 4 channel amp to run those, infinity DVC 10" kapper perfect 10" sub wired in series so tha amp sees 8ohms, polk c500 mono amp to run that, and the sweet pioneer DEH-P77DH seemingly infinitly adjustable HU.
    I ran some mozart to hear the pure sound, some megadeath for the deeps, some nugent for pure hard rock...man I think I'm going to like this system, alot. I started hearing new music in CD's I've been listening to for years.
    Thanks alot for all the help and suggestions and advice and knowledge It was most invaluable.. I'll dial the amps in perfect once the rest of the truck is done, probably fall time....but in the mean time I think I'll ditch the garage aiwa boom box and just rig up the K5 system instead!
     

Share This Page