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age old question. subs facing front or back?!?!?!? help!!

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age old question. subs facing front or back?!?!?!? help!!

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quick question guys, ok i havw a 1987 mazda rx7 (hatchback if ur not familiar) and i am getting a pretty nice pre fab box. now i kno im gonna have to make my own or have on made once i have the money but anywayzzzzz i have three 12 inch kenwood w3013ps subs being powered by a hifonics 1200 rms amp,so my question is that since im already having space issues i def dont wanna re do my set up until i custmize my box so should they face forwards or backwords? ive read that ppl say subs bounce off of windows etc. and also read that thats not true so i turn to my cf family for this. i def trust ur oppinion over anyone elses!! they would look cooler facing front but i want the best boom so thanks for reading and have a great day-night....

Verified Answer
  • Not sure if I am reading this correctly, but ...

    I'm pretty impressed you found a box that will fit three 12's in an RX-7 period.

    You are saying that the box is also configurable enough that you can fit the subs facing either forward or backward?

    It is really going to vary with vehicle acoustics, and there isn't an easy way to predict it without stealing what JL does with their stealthboxes or similar, but often subs benefit from "corner loading" - which is pointing the subs toward a corner or the rear wall of the trunk, etc.

    Not that three 12's in an RX7 are going to sound weak if you had them face down without an air gap beneath them ...

    On the box - they are SVC-4-ohm subs.  It doesn't matter if you make the wiring connections at the subs or the box terminals.

    Just wire one sub to each terminal pair, then run a wire from the amp to terminal 1, from terminal 1 to Terminal 2, and from Terminal 2 to Terminal 3.

    You want to assume 1200W RMS and 1.333-ohms, but you don't even need very big wire for that - 18-gauge is supposed to be okay.

    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

All Replies
  • also i was wondering since my box has three chambers and three speaker terminals can i wire the subs in sequence from one term to the other? i want to run them at one ohm well 1.3 to be exact but since box is sealed i cant wire the vc together sry for this lame question but i want my stuff perfect the 1st time lol. thx again guys i wldnt buy anything before getting some advise from u 1st.......

  • Not sure if I am reading this correctly, but ...

    I'm pretty impressed you found a box that will fit three 12's in an RX-7 period.

    You are saying that the box is also configurable enough that you can fit the subs facing either forward or backward?

    It is really going to vary with vehicle acoustics, and there isn't an easy way to predict it without stealing what JL does with their stealthboxes or similar, but often subs benefit from "corner loading" - which is pointing the subs toward a corner or the rear wall of the trunk, etc.

    Not that three 12's in an RX7 are going to sound weak if you had them face down without an air gap beneath them ...

    On the box - they are SVC-4-ohm subs.  It doesn't matter if you make the wiring connections at the subs or the box terminals.

    Just wire one sub to each terminal pair, then run a wire from the amp to terminal 1, from terminal 1 to Terminal 2, and from Terminal 2 to Terminal 3.

    You want to assume 1200W RMS and 1.333-ohms, but you don't even need very big wire for that - 18-gauge is supposed to be okay.

    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

  • thanks so much man!! the box is an absolute tss12 one sub facing out and one on each side at an angle. i can have it right behind my seats facing backwords or at the rear facing the front. i have two storage compartments right behind me that i would love to use after the install so i want to place the box at the rear facing front(plus it will look cool in the car lol) but ive heard from friends that facing them front decreases the bass that u hear. but the fact that im in an rx7 i really dont think it will matter! haha  i just wanted to ask a pro. im not a newb by any means but i usually have pro installs. i just moved to bum ***  middle of nowhere michigan and dont kno anyone here and its hours to a reputable audio shop so this one is all me......and u ofcourse lol but thanks for the help again. where are u at maybe i can get u to hook up and tune my set up lol. one more thing my hu only has one preout for an amp so will having a monoblock amp affect the speakers that arent hooked to it? (front and door speakers) i never had two amps and i cld swear that in my last system  my speakers got louder once i had them installed and tuned by a pro. they used to distort at 40 out of 62 but after the install i could only go to 32 without going def. i dont have good front and rear speakers right now. i have some cheap memphis 4" in the front and sony xploders lol in the doors and rear and they dont sound to great now. def next on my list but will they get louder after i install subs? sry for the long post and dumb questions but like i said ive never had to be this hands on!!! once again thanks sooo soooo much!!! i recommend u to all of my friends and anyone i kno looking for help. ive even had ppl  at the audio shops in florida looking up stuff from this website before installs so needless to say ur awesome!!!

  • Pretty cool box.

    Not trying to be a smart-***, but if I read correctly, you're running your main speakers off the head unit only and adding three 12's with a 1200W RMS amp, and you're worried about the installation position maybe decreasing the bass you will hear?

    IOW - my guess is they would probably be louder facing the rear.  My guess is you would ideally set the gain so the amp is only putting out maybe 400W RMS if you don't want to drown out your mids and highs, and even then it might be too much.  IOW - Having the mounting position decrease the bass output should be the LEAST of your problems.

    Exactly what make and model head unit do you have?

    Is there a main amp at all?

    Your car should have 5-inch dash speakers, 6.5-inch door speakers and 6.75-inch rear panel speakers - which isn't a bad starting point.  I would probably ditch the dash speakers - which I assume are the Memphis 4's.

    What model are the Sony speakers?

    KICKERkrazzyyy
    where are u

    I'm near Atlanta, but I'm okay with the electrical theory (well, I'm probably better than that), but I'm not sure I'd be much help with the install or tuning.  I can give you pointers, though.

    KICKERkrazzyyy
    but will they get louder after i install subs?

    Yes and no.  Technically, no, adding subs won't make your main speakers louder.  Now, main speakers distort when they try to play low bass that they weren't designed for and that limits their power handling - so if your subs are playing the low bass, you can block that from the main speakers and then you can feed more power to them without them distorting, so in that sense they can be louder, but that is based on you being able to high-pass filter them and supply them more than recommended power (basically based on having a 4-channel amplifier).

    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

  • ok the hu is a cheap pioneer i cant recall the model but i think its the deh1300 its 50x4 and has the usb and mp3 jack.  I have never installed any of my systems in the past, but my last car(another rx7) had 2 cvrs and a 900w kenwood amp 2ch i believe. now before the install my front and rear speakers distorted at volume level 40 out of 62 with the bass at -2 mids at +4 and treble at +5 and it was kinda loud. but after the install with only an amp feeding the subs they seemed way louder at just 20!?after the install i kept bass on hu @ -6 always, and it rocked!!!  i didnt have an amp going to them either so i was just wondering if by installing an amp that feeds only subs in this car and keeping hu bass @-6(lowest it will go) if it the subs would drownd out my mids and highs or if the hu wld see i had an amp and feed more rms to my fronts and doors and rears. i currently dont have any door speakers. the dash speakers are 4" the doors are 5 1/4, and i have some cheapo sony explodes 6.5s in the back. once i get another paychek or two i plan on upgrading my speakers and eventually hu but for now i just cant do it without not paying rent lol.  Also the dude at the only audio shop around here sold me these memphis 4s and told me that they rocked out for the size, i got home stoked to install and ditch the beat up stocks only to see that they were cheap paper cones and tiny tweeters. i wouldve expected more from a good cmpy. like memphis....oh well lesson learned.

    okm now that im on subject....my car has 70amp alternater and im already gonna be straining it with this hiphonics amp that runs 1200rms, how much more wld a small 250w or 300w amp drain on  top of that and my hu only has one preout so can i even hook another amp up to it? thx so much... 

  • KICKERkrazzyyy
    i got home stoked to install and ditch the beat up stocks only to see that they were cheap paper cones and tiny tweeters. i wouldve expected more from a good cmpy. like memphis....oh well lesson learned.

    i'm not sure Memphis is the "good cmpy" you think it is.  they tend to copy what works, and haven't been particularly innovative.  seems to me they could exist the way they are despite having no product development department at all. 

    what is the exact model number for the amp you have?  1200 watts is a big power draw... even assuming it's class D, you're looking at 110 amps just to get RMS (and that includes nothing as far as stock electrical demands).  alternator def seems like a weak point to me, but that assumes 1200 watts RMS, not Peak, or MAX.

  • so if i get a cap will it help? if so how big should i go? local audio shop has a 1 farad for a decent price

  • KICKERkrazzyyy
    if the hu wld see i had an amp and feed more rms to my fronts and doors and rears.

    It doesn't work that way, but you provided your own answer earlier.

    Main speakers (meaning 4-inch, 6.5-inch) don't handle low bass well.  With the bass at -2, the speakers distort at volume 40 of 62 (say maybe 12W RMS or so).  With the bass at -6, you can probably go to 50-55 on the volume and the speakers are louder b/c they are getting more power.  (Not b/c the head unit knows you have an amp, but b/c you are further up on the volume, so they are getting more power).

    Normally, -6 on the HU would sound bad, but with the subwoofer, you can increase it's output to compensate for that and make up for what you are taking away from the HU.

    KICKERkrazzyyy
    the dash speakers are 4" the doors are 5 1/4, and i have some cheapo sony explodes 6.5s in the back

    CF shows the doors as 6.5 or 6.75.  Recommend at a minimum moving the rear speakers to the doors and then maybe getting better rear speakers (and maybe running the dash speakers off the HU.

    KICKERkrazzyyy
    how much more wld a small 250w or 300w amp drain on  top of that and my hu only has one preout so can i even hook another amp up to it?

    It won't help.  More info below, but the sub amp will draw 109A at clipping.  A 200W main amp would draw 30A, but you aren't as likely to reach max power with it as you would with a subwoofer amp, and it tends to not have the voltage dips and headlight dimming that you get with a subwoofer amp.

    You could definitely add one, you just need an amp with speaker-level inputs, or you need a LOC.

    KICKERkrazzyyy
    what is the exact model number for the amp you have?  1200 watts is a big power draw... even assuming it's class D, you're looking at 110 amps just to get RMS (and that includes nothing as far as stock electrical demands).  alternator def seems like a weak point to me, but that assumes 1200 watts RMS, not Peak, or MAX.

    It's a BRZ1200.1d.  J Ro, you would know more than I would, but the amp only draws 110A at clipping - i.e. when you are playing test tones sustained at max volume.  In normal use with the volume maxed, I would expect the amp to draw about 40A on average (bass hits about 1/3 of the time.)  And that's assuming you are pulling 1200W when the bass hits, which you might not want to do with a head unit only on the main speakers.

    It's not great on a 70A alternator and you probably will have headlight dimming and possibly some electrical (dead battery) issues as well.

    KICKERkrazzyyy
    so if i get a cap will it help? if so how big should i go? local audio shop has a 1 farad for a decent price

    Caps are generally a waste of money.  (J Ro - did you read me saying that?).  Short answer, if your ONLY problem is mild headlight dimming, they might help.  If the battery is dying, you need a bigger alternator and more/larger batteries can't hurt either.  If you wanted to add a capacitor, 1F/1000 watts subwoofer is minimum, but 2F is recommended, so something like a 2.4-Farad would be ideal with that subwoofer amp.  From what I've read, a smaller cap puts ADDITIONAL strain on the charging system while going above 2F/1000W RMS doesn't do any harm but doesn't benefit you either.

    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
    It's a BRZ1200.1d.

    you'd definitely experience headlamp dimming with that amp and your stock alternator, at least during periods of heavy bass demand, and a cap simply can't bridge a 40 amp deficit between amplifier demand and alternator supply.  you'll have to either turn it down, or live with dimming headlamps (and greatly reduced alternator life).  this is most definitely a situation that would benefit from a HO alternator, and leave the cap idea out (at least for now... might help, but i'm not a fan of CAPS.  i quietly demonstrate my angst against CAPS pretty much with every post i make).  they are likely some very specific situations where a CAP will be the fix, but i very much doubt this is one of them.