Free Shipping on Everything.
60-Day Money-Back Guarantee | Lifetime Tech Support

4 Speakers + 1 Sub to 4 Channel Amp

Car Audio, Video, & GPS

Car Audio, Video, & GPS
Talk about stereos, navigation, amps, subs, and all things car audio

4 Speakers + 1 Sub to 4 Channel Amp

  • I know this question has been asked by a few, but I would like a more informed answer on my set up. Below are my current system specs, but to get to the crux of my question please click here

    --------------------------------------

    Head Unit -  Sony MEX-BT3800U

    • Preamp Outputs: 6-channel
    • RMS Output - 17 watts

    Speakers - Sony Xplod XS-GTX1640

    • RMS Output - 75 watts
    • Impedance - 4 Ohms

    Amp - Sound Storm EV4.400

    • RMS Output at 4 Ohm - 50 Watts x 4
    • RMS Output at 2 Ohm - 100 Watts x 4

    --------------------------------------

    I know my current Amp is under powering my speakers but I have the gain all the way down and I dont turn my system up too loud right now...

    I want to get this Amp:

    Autotek M1400.4 <Mod Edit: Linked to Manufacturer's site. Please link to Crutchfield's Item Page or manufacturer's website. Thanks.>

    • RMS Output at 4 Ohm - 88 Watts x 4 chan
    • RMS Output at 2 Ohm - 175 Watts x 4 chan
    • RMS Output at Bridged 4 Ohm - 350 Watts x 2 chan

     

    Now my question is can I run my 4 speakers + a sub off of that Amp? The sub will probably be something like 150-300 RMS at 4 ohms (dual voice coil?).

    I am a novice at this stuff but I understand some of it and if you are willing to give an explanation with an answer, it would be greatly appreciated. I would like to only know possible set ups as far as my current equipment, the Autotek amp, and a sub would go. One of the reasons I am having to post this is because most of the answers out there are things like "get a mono amp for the sub and better multichannel for the speakers" or "get a 5 channel amp." That's an obvious answer but not what I am looking for. 

     

    Thanks for the help...



    [edited by: Ryan at 4:37 PM (GMT -5) on Wed, Mar 2 2011]
  • You could make it work, with some catches.  You could run all 4 of your sony speakers of the 2 front channels of the Autotek amp, two speakers wired in parallel to each channel, which would present a 2 ohm load to the amp at each front channel, and each speaker would bet receiving about 87 watts RMS. Not bad.  Only problem is you would lose your fader ability.

    Then you could run a sub off the rear channels bridged at 4 ohms.  So ideally you would want a sub capable of handling around 350 w RMS, either 4 ohm single voice coil or 2 ohm dual voice coils.

    Hope that helps, anyone else care to weigh in?

    1998 Honda Prelude, Pioneer DEH-P9400BH + Sirius tuner, Kicker KS6.2 front components, Kicker KS6930 rear speakers, Alpine MRP-F300 for speakers, Alpine SWR-1022 in ported box, Rockford Fosgate Punch 501s for sub.

  • oh one more thing.  You would want to run the front RCA preouts from the head to the front channel inputs on the amp, and the sub rca preouts from the head to the rear channel inputs on the amp.  Then you would want to use a HPF for the front channels and a LPF for the rear sub channels, either from the head unit or on the amp directly, really a matter of personal preference.

    1998 Honda Prelude, Pioneer DEH-P9400BH + Sirius tuner, Kicker KS6.2 front components, Kicker KS6930 rear speakers, Alpine MRP-F300 for speakers, Alpine SWR-1022 in ported box, Rockford Fosgate Punch 501s for sub.

  • Ok, just what I was thinking. And my understanding of parallel is for instance:

    • (+) front left/right speaker into the (+) front left amp
    • (-) front left/right speaker into the (-) front left amp
    • (+) back left/right speaker into the (+) front right amp
    • etc...

     

    Is this correct?

    And I'm sure if I googled it I could get all kinds of opinions. But do you know personal if running the speakers this way has less sound quality (2ohms vs 4ohms)? I am also guessing that I would want to run the amp on 3 CH bridge mode for this set up correct?

    If I really have to I'm willing to leave the 400 watt amp in there to power the back speakers and just use 2 channels for the front 2 on the Autotek (even though the 400 watt doesn't have bridge so I would be under powering the speakers).

  • Okay - the EV4.400 is a terrible amp - it has a 15A fuse and is probably less powerful than the Sony Head unit alone.

    You do have a couple of other options, though:

    • Normally, I would recommend bridging the SSL amp to the rear speakers and running the fronts off the Autotek front channels and the sub off the Autotek bridged rear channels.  You are correct though that the Autotek amp does not show any sort of bridging options.
    • Another option would be running the rear speakers off the head unit as above and not using the SSL amp - can work well in a small car.
    • Your option as mentioned would work with the caveats that Columbus mentioned.

    Potential
    Ok, just what I was thinking. And my understanding of parallel is for instance:
    • (+) front left/right speaker into the (+) front left amp
    • (-) front left/right speaker into the (-) front left amp
    • (+) back left/right speaker into the (+) front right amp
    • etc...

    Is this correct?

    Close - but you probably want to run the right and left sides in parallel so you still have stereo imaging - so it would be:

    • (+) front/rear left speaker (+) into the (+) front left amp
    • (-) front/rear right speaker (-) into the (-) front right amp

    Potential
    But do you know personal if running the speakers this way has less sound quality (2ohms vs 4ohms)?

    In theory, you get better excursion control of the speaker at higher impedance - however, the speakers are still at 4-ohms (the amp is at 2-ohms), so I'm not sure it matters in this case - I'm not sure you'd HEAR the difference in any case.

    Potential
    I am also guessing that I would want to run the amp on 3 CH bridge mode for this set up correct?

    Yes - that would be the most logical - you also will need to split the RCA's to the CH3 and CH4 inputs for the subwoofer (unless the amp has a toggle switch that does this).

    Hope This Helps!!!

    Anyone else have suggestions?

     

    2002 Ford Focus JVC KD-A815 Sony CDX-GT410u Sony XT-100HD HD Tuner Stock speakers, no amp, no subs

  • TigerHeli

    Okay - the EV4.400 is a terrible amp - it has a 15A fuse and is probably less powerful than the Sony Head unit alone.

    You do have a couple of other options, though:

    • Normally, I would recommend bridging the SSL amp to the rear speakers and running the fronts off the Autotek front channels and the sub off the Autotek bridged rear channels.  You are correct though that the Autotek amp does not show any sort of bridging options.
    • Another option would be running the rear speakers off the head unit as above and not using the SSL amp - can work well in a small car.
    • Your option as mentioned would work with the caveats that Columbus mentioned.

    The EV4.400 is ok, but I agree definitely not anything worth wasting money on. I just wanted an amp to control the Sony speakers I added in. The Autotek DOES have bridging (2/3/4), the SSL doesnt which is a big reason why it was a waste of $40. But I rather run speakers on that then try it on my head unit (17 RMS I think?). 

    Thanks for the set up clarification also as far as running it parallel goes. When connecting the speakers parallel is it best to join them at the amp, a wire point, or is it just preference? 

    And my head unit has sub outputs. So isn't it best to just connect my Ch3/Ch4 to that or should I just go with the Rear Left/Right and run LPF?

  • I had one thing wrong, but you are misunderstanding some things as well - no offense ...

    Potential
    The EV4.400 is ok, but I agree definitely not anything worth wasting money on. I just wanted an amp to control the Sony speakers I added in. The Autotek DOES have bridging (2/3/4), the SSL doesnt which is a big reason why it was a waste of $40. But I rather run speakers on that then try it on my head unit (17 RMS I think?).

    The Sony HU has a 10A fuse and outputs 17W RMS.

    The EV4.400 has a 15A fuse (same as my JVC) and probably outputs around 20W.  THAT is why it is a waste of money.

    Your Sony speakers handle 75W RMS.  Where I think you are getting confused (you said the gains were DOWN on the EV4.400) is that you could blow them with a true 50W amp and a clipped signal, but you can't really hurt them with the EV4.400 or the Sony HU, regardless of what you do.  See this thread.

    Potential
    Thanks for the set up clarification also as far as running it parallel goes. When connecting the speakers parallel is it best to join them at the amp, a wire point, or is it just preference? 

    It makes no difference.  The shortest and cleanest wiring would be to run wire from the amp to the front speakers and then from the front speakers to the rear speakers.  However, in car audio - the easiest and most common thing to do is to run them to the amp and connect them there - this also has the advantage of reducing the confusion factor if you or someone else removes the amp or adds a 4-channel amp for the main speakers (or a separate subwoofer amp) later.

    Potential
    And my head unit has sub outputs. So isn't it best to just connect my Ch3/Ch4 to that or should I just go with the Rear Left/Right and run LPF?

    Yes, connect the sub outputs to CH3 and CH4.  Somehow I was confused and was thinking the amp had CH3-L and CH3-R inputs, but it does not - Brain Fade!!!

    (Also, you want the switch on 3-channel, but I'm not sure what it does.  (I.e. most amps will operate in 2-channel, 3-channel, or 4-channel mode simply based on what you connect to the outputs, so I'm not sure why it needs a switch ...)

    Hope This Helps!!!

    Anyone else have suggestions?

    2002 Ford Focus JVC KD-A815 Sony CDX-GT410u Sony XT-100HD HD Tuner Stock speakers, no amp, no subs

  • Just wanted to point out - Those are not RMS figures for the Autotek amp - Autotek only quotes Max power specs and some competitors cut those in half and CALL them RMS numbers.

    The amp has a single 50A fuse - it would be predicted to do about 350W RMS, which would mean around 175Wx2@4-ohms, 87.5Wx4@2-ohms, and about 60Wx4@4-ohms.  (Based on this and based on comparisons with the S/O M-4050 (40A fuse) and M-4075 (60A fuse)).

    That will work fine, but your speakers will only get 40W RMS each and you might want a less powerful sub - or if you really want the claimed performance for that amp - you might look into the Hifonics ZXi80.4, S/O M-4075 or Infinity 475a - not that it would make a huge difference.

    Hope This Helps!!!

    Anyone else have suggestions?

     

     

    2002 Ford Focus JVC KD-A815 Sony CDX-GT410u Sony XT-100HD HD Tuner Stock speakers, no amp, no subs

  • No offense taken. Like I said, I am here to learn.

    Thank you for the link to the thread on over/under powering speakers! It had plenty of information and gave me something to do in my sociology class. 

    Now from what you are saying I take it I can pretty much say "forget RMS power" (as it applies to output to the speakers) and pay more attention to the fuse sizes? So basically if I really want to reach a true around 75 RMS for the speakers I would need an amp with around 100 RMS x 4 AND a 60A Fuse? And would I really be able to tell the difference in sound with a higher RMS powering the speakers?

    The EV4.400 I have in there now doesn't sound bad. My car is small and the speakers make the back cover rattle when the base is up too high (main reason for getting a sub) but produces good sound otherwise. You can hear it clear across the parking lot. But then again, I do not have a trained ear for these kind of things or anything else to compare it to. From the sounds, I might have more knowledge than most of the audio shops around here. Which is very sad

     

  • I wouldnt say forget RMS figures.. they are usually accurate in good brands. But you have the idea down perfectly. With the RMS vs the fuse rating. Thats really the best way to check. Another good thing to look for is CEA-2006 Complaint amps. Those are amps tested at 14.4 volts to put out such rated power. Also keep in mind.. you probably arnt running at 14.4 volts with a load such as a couple of amps. So even there i say be careful. I own an amp thats rated 1200RMS has 140 amps of fusing. Is a class D. Cea certified. Yet i can only get about 1000RMS out of my amp with my car at 13.8 and with some drop. Many factors to account for :S 

    JVC KD-AVX44, 2 Massive Audio Hippo 8's , Hifonics Colossus going back in soon, MB Quart ONX216, Fli audio FL450S-F2, Energy ENC693x2 in rear deck, 6 gauge kit plus a huge 3 gauge kit. Custom built box for my 8's :)

  • Shak nailed it and you almost got it but missed some of the finer points.

    Amps vary anywhere from quality amps like Kicker (some limited settings, though) that might put out 900W RMS when they are rated at 750 to amps like (well...) your SSL that is rated at 50W RMS at 4-ohms and is lucky if it does 20W RMS.

    This part will get complicated, and I usually forget to change the settings, but ... First the easy way - I trust the Infinity 475a to put out rated power - it is 75Wx4@4-ohms, 90Wx4@2-ohms, has 70A of internal fuses.  If you go here,  (it works well for subwoofer amps b/c it shows max RMS power), put in 14.4 for the battery voltage and Class AB and 360W for the amp output -  You come up with a 50A fuse - so either the Infinity does a bit more than rated (I think the S/O M-4075 had a 60A fuse), or it is a bit more inefficient than BCAE1 predicted 50% efficiency - it would be 38% - or a combination.

    The key thing here is if you find an amp like your SSL that is supposed to do 400W RMS (100Wx4 RMS at 2-ohms) with a 15A fuse - the amp has to have 200% efficiency to achieve that - clearly that isn't going to be happening, so they are lying about the figures.

    (BTW - there is a valid reason behind this) - I'm sure you are saying "Why doesn't SSL just put 50A of fuses on the amp, even if it still only does 20W RMS per channel?"  Bottom line is liability - they could, but the amp will not handle 50A of current.  If your car catches fire b/c the amp overheats, they have a lawsuit on their hands.  If they built the amp with better components that could actually handle 50A, they might as well increase the output while they were in there.

    Potential
    The EV4.400 I have in there now doesn't sound bad. My car is small and the speakers make the back cover rattle when the base is up too high (main reason for getting a sub) but produces good sound otherwise. You can hear it clear across the parking lot. But then again, I do not have a trained ear for these kind of things or anything else to compare it to.

    I didn't say it was a bad amp.  (Oh wait, I said terrible ... Devil).  If you want a 20Wx4 external amp, it's a great choice.  If you bought it for a 50Wx4 amp, you got ripped off.  Here's the thing - your Sony probably outputs 17W RMS per channel, but you likely have never run it without the SSL amp connected.  If you have some free time and want to mess around - connect your rear speakers to the Sony rear channels instead of the SSL and compare front and rear - I bet the fronts will sound SLIGHTLY better but not dramatically.  Which brings me to:

    Potential
    And would I really be able to tell the difference in sound with a higher RMS powering the speakers?

    It's easier for you to experience than it is to explain - but there is a law of diminishing returns with amplifier power.  The OEM radio in your car was probably around 4-6W RMS (per channel) and a weak link.  The Sony or the SSL is 20W-ish and dramatically improved.  It will be loud with the windows up - but not really loud at highway speeds with the windows down.  When you go to say 50-60W RMS with an aftermarket amp, of course you get more volume, but the main improvement is clarity and dynamic range.  (i.e. your stereo now when you turn it up will sound like it is "trying" to play loud.  With the bigger amp, it will play a quiet passage, and then slam you in the chest and make your hair stand up with clean sound when the song gets loud.  Beyond this - going from say 60W to 75W, you'll pick up slightly more clarity, but not a huge amount - that's basically why I didn't slam the Autotek amp too hard above - it's not 88WRMSx4, but it is probably 60Wx4 - and that's decent for your speakers - you just need to know that is what you are buying and compare it based on that.  (Same thing for the SSL - for example, if you had stock speakers and the OEM amp died and you didn't want to change out the OEM head unit or the OEM speakers - it's your amp!!!).

    Potential
    From the sounds, I might have more knowledge than most of the audio shops around here. Which is very sad

    Again - no offense, but no, you don't.  I don't mean to paint all car audio shops with the same brush, but there are a lot of shops that will say "I have this great SSL amp and these great Pyle speakers I can sell you that you'll really like" - which translates to "I have a larger profit margin on these SSL and Pyle products, so I'd like to sell you these ..."

    Hope This Helps!!!

    Anyone else have suggestions?

    2002 Ford Focus JVC KD-A815 Sony CDX-GT410u Sony XT-100HD HD Tuner Stock speakers, no amp, no subs

  • TigerHeli
    Again - no offense, but no, you don't.  I don't mean to paint all car audio shops with the same brush, but there are a lot of shops that will say "I have this great SSL amp and these great Pyle speakers I can sell you that you'll really like" - which translates to "I have a larger profit margin on these SSL and Pyle products, so I'd like to sell you these ..."

    Trust me, these guys don't know anything past their own products. I'm NOT saying this is true for everywhere, but I am in a small town (Statesboro, GA) for school. They have over the top prices with just 3 different kinds of products and if you start talking technical details they start to get panicky and make up pretty much anything to sound like they know. I won't go into the whole story but both had stupid answers for my questions such as "the RMS depends on what size speaker wire you use". I do not claim to be an expert of any kind on car audio, that's why I am here, but I know enough to know that was wrong. Definitely was not claiming to have superior or even sufficient knowledge compared to a real audio technician or anything lol

    But thanks for the explanation guys and also with the diagram Tiger, really helped! 

    Autotek isn't on the CEA-2006 list but the manufacture maxxsonics is (Also makes hifonics products?). Even if they weren't on the list I still think I'm gonna give them a try. My goal here is to get an amp and sub for AROUND $200 (+$50 available in budget) that will have nice clean bass and nice clean sound from the speakers without shaking my cheap plastic car apart (thats why I dont want to put expensive equipment in it). I'll upgrade the sub and amp when I get my mustang back.

    And I have one more question as far as impedance goes: I see that most amps have a minimum impedance of 4 ohms bridged and 2 ohms unabridged. From my understanding, when you do parallel wiring of speakers you divide the the speakers ohm rating by number of speakers. I take it the amp's ohm input rating is per channel so making 2 sets of speakers run parallel brings the impedance of the speakers down to 2 ohms per channel correct? Meaning that if channel 1/2 were running my speakers that would be unabridged and is running on that minimum? Also meaning bridging channels 3/4 for the sub means I need a sub running on at least 4 ohms? 

    Thanks for the help guys!

  • Potential
    I'm NOT saying this is true for everywhere, but I am in a small town (Statesboro, GA) for school.

    Go Eagles!!! (???)

    If the local shops aren't good, you're not far from a road trip to Macon or Savannah or Charleston or even Atlanta, but you can still probably find the info and better prices on line.

    Potential
    I won't go into the whole story but both had stupid answers for my questions such as "the RMS depends on what size speaker wire you use".

    Not defending them, but hard to fault them when Infinity says the same thing - "True Four Ohm Impedance technology: speaker's 2-ohm impedance combines with speaker wire impedance for a 4-ohm load"  My counter to that is here - maybe if you used 32-gauge speaker wire or something ridiculous - the words sound nice, though.

    Potential
    Autotek isn't on the CEA-2006 list but the manufacture maxxsonics is (Also makes hifonics products?). Even if they weren't on the list I still think I'm gonna give them a try.

    .

    There are worse (and better) amps you could go with - for a bit more, I like the JL J2 360.4.  For about the same price, I like the Hifonice HFI100.4  (expect about 3/4 of rated power, but that's fine), Rockford Prime R300-4, JBL GT5-A604, and to a lesser extent Kenwood KAC-8405.

    Yes, Autotek is made by Maxxsonics and so is Hifonics and Hifonics is a quality product, but MB Quart and Crunch are also made by Maxxsonics as well - Things I don't like about the amp:

    • Many companies have an entry level brand that isn't quite as good as their main brand but is almost as expensive - to some extent that applies to the RF Prime amp above, but Rockford Non-Prime amps are excellent, but pricey.
    • I try to avoid any amp that not only is non-CEA certified, but also does not even quote RMS specs (on the manufacturer's site) for the product.
    • Autotek USED to be a great brand - 20-30 years ago, they had Mean-Machine amps that were 1-ohm stable bridged, 0.5-ohms stable stereo, did about 3x advertised power.  I somewhat have a problem with manufacturers using the name of the old product with a new lesser product and hoping consumers will have heard of the old product and think it is still as good.  (Not as bad though as selling a similarly named but completely different product, though - Kole Audio instead of Kove Audio or Lanzar VIBE instead of VIBE Audio, though).

    Potential
    My goal here is to get an amp and sub for AROUND $200 (+$50 available in budget) that will have nice clean bass and nice clean sound from the speakers without shaking my cheap plastic car apart (thats why I dont want to put expensive equipment in it).

    Including a box and wiring kit, or not? - should be possible though.

    Potential
    From my understanding, when you do parallel wiring of speakers you divide the the speakers ohm rating by number of speakers.

    Not quite - for 2-speakers the impedance is half of the single speaker impedance.  For more than 2 speakers, it is the reciprocal of the sum of the reciprocals of the impedance, but it's easier to just go here.

    (Actually, it does work out the way you said it if all the speakers have the same impedance and they have to or else one speaker will see more power than the other one - I didn't realize that, but it works out that way).

    Potential
    I take it the amp's ohm input rating is per channel so making 2 sets of speakers run parallel brings the impedance of the speakers down to 2 ohms per channel correct? Meaning that if channel 1/2 were running my speakers that would be unabridged and is running on that minimum? Also meaning bridging channels 3/4 for the sub means I need a sub running on at least 4 ohms? 

    Correct on all counts.  You are going to be wanting an SVC (single-voice-coil) 4-ohm sub or DVC-2-ohm sub wired at 4-ohms at the amp.  And you will probably want a 150W to 250W RMS sub even though some of those amps CLAIM to do more than that.  There are LOTS of subs in that range.

    Hope This Helps!!!

    Anyone else have suggestions?



    [edited by: TigerHeli at 10:24 AM (GMT -5) on Sat, Feb 26 2011]

    2002 Ford Focus JVC KD-A815 Sony CDX-GT410u Sony XT-100HD HD Tuner Stock speakers, no amp, no subs

  • Yes! Go Eagles! [Proud student of GSU!]

    Thanks for all the help! I think I'm ready to buy. Thanks for the heads up on the Hifonic HFI100.4. After a little comparison I think it's the better choice for just a few dollars more. My only disappointment is that the Autotek had the nice LED ring (I have blue lights running through out my car). 

    I already have a 10" box for a sub so I think I'm gonna go with the JL Audio 10WX-4 <Mod Edit: Linked to Crutchfield. Please link to Crutchfield's Item Page or manufacturer's website. Thanks.>

    What you think? Either that sub or a Sony Xplod XS-GTX110LW <Mod Edit: Removed competitor link.  Per our linking policies, please link to the manufacturer or to the Crutchfield site whenever possible. thanks. > from walmart (just because its right there in the store and the ratings arent bad). I know most people's rule of thumb though is that if walmart sells it, stay away. 

    Thanks!



    [edited by: TigerHeli at 12:24 PM (GMT -5) on Sat, Feb 26 2011] http://www.sonicelectronix.com/item_25660_JL-Audio-10WX-4.html http://www.walmart.com/ip/Sony-Xplod-XS-GTX110LW-10-Car-Subwoofer/12016334
  • Potential
    My only disappointment is that the Autotek had the nice LED ring (I have blue lights running through out my car). 

    If it's any consolation, I'm pretty sure the "HF" lights up in blue ...

    Hard to go wrong with JL.  I hear what you are saying about Wal-Mart, but they also carry JVC and Pioneer HU's.Devil  I thinks Sony's subs (and speakers) are better than most of their other audio, but the thing I'm not crazy about is those subs are 300W RMS and the HF amp is likely around 200W bridged on the rear channels (I know it's rated for 400W) - The JL seems like a better match for it to me.

    Hope This Helps!!!

    Anyone else have suggestions?

    2002 Ford Focus JVC KD-A815 Sony CDX-GT410u Sony XT-100HD HD Tuner Stock speakers, no amp, no subs