I still havent gotten this thing down yet. How can you hook up a mono amp to 2 subs? And that whole OHMS thing I havent gotten down. How do you control what your ohms is on your sub? And is it possible to hook up 4 aftermarket speakers to your head unit instead of an amp? SORRY IM A NEWB!
Replies (5)
Halflifehavock13 on 07/1/2004 11:58:36
I have a 2004 blazer 2 door. I wanted to put 2 12" rockford fostgate T112D2 or T112D4. I dont know which one to go with. What amp would be best for 2 of those subs (and I dont mean what company, but what class amp, wattage and channel)
Halflifehavock13 on 07/1/2004 11:59:12
oops, I was hoping to have a 75/25 SQ-SPL
uochronos on 07/1/2004 15:12:22
alot of info required for this explanation
first off as far as what class amp to get..
for subs we recomend a calss D or class T amp. mone(1 channel) these amps are built for subs and are extremly effecient mening almost all the power they draw from your battery they use to make sound. unles a class A/B which only about 60% of the energy it draws well make sound the rest is just lost in heat.
as far as hooking up 2 subs to a mono amp you well simply wire the 2 subs together in either parelel or series or parrelel/series. and then wire that to your amp. here is a great site that shows you almost all the wioring combinations.
http://www.phoenixgold.com/tutorial/wiring_tutor.html
now for ohmage this one is a bit confusing and took myself awhile to understand it bassicaly your speaker has a set ohmage most car subs have a single 4 Ohm voice coil(VC) , a single 8 Ohm VC, dual 4 ohm VC's, or Dual 2 Ohm VC's,
the 2 you mentioned have dual 2 and dual 4 ohm VC's..
now which you get well matter on was amp you get and howmany subs you get assuming you get a class D amp which most Class D amps are stable at 2 ohms. and you get 2 subs you would want dual 2 ohm subs. and would want them wired as follows
you would take each sub and hook the negitive from one VC to the positive of the other VC. do that on both subs. that well add the Ohmage of each VC and make each sub a 4 ohm load. then you well run the positive that still open on one sub to the positive thats open still on the other and run that to the positive on the amp then you well run a wire from the negitive that hasent been used on onesub the the negitive that hasnt been used on the other sub. then run from there a wire to the negitive on the amp. the second part runs the subs in parrelel which cuts the Ohmage in half neting you a 2 ohm load which is what most class D amps are stable at.
you can refer to the web site i mentioned earlier to get a picture of what wireing like that well look like..
the basic idea behind ohmage is if you run it in parelel positive to positie and negitive to negitive then to amp you well cut the subs ohmage in half. but if you run in series which is negitive to positive and then runing the open positive and negitive to the amp this well double the ohmage from say 4 ohm to 8 ohm.. that web page is really a handy tool since it visualy shows you how to do it and what result it well get you.
so as far as which one of the subs you get it well relie entirly on what amp you get the subs youi mentioned are identical except for the VC ohmage which only changes what amp they well work with.
Ok now for the speaker question you can hook up 4 after market speakers to your HU assumeing it has 4 set of speaker wires.. although a modest amp well help alot with sound quality.
just looked up the subs you mentioned these are some power full subs you want here 600watts rms a piece... you well need a 1200watt RMS amp to power these....JBL makes a good solid amp called the power valve series can usualy be had on ebay for around 250-350$ would work well for your subs. also phonix gold tantrum series can be had for right around 300$ for there 1200watt version off ebay if you shop it well..
I do see one problem that may occur here a 1200watt amp well pull alot of power right around 100amps if turned up all the way around 50-70amps when listening at normal volumes. your stock electrical system may not be able to handle this... i have a 2003ranger which had 110amp alternator stock and a 500watt amp would dim my lights when my headlights and heat was on... a 1200watt amp can easily do that and more... find out how large your stock alternaotr is if its 120-150 you may be alright but if its 120 or less you well need to upgrade or face alot of anoying problems down the road...
or there is a second option get just one opf these subs... you ask wont that be half as loud? no it well not cutting out one subs or droping the RMS wattage in half only lowers the volume 3 DB which is not very much at all... you could even do asw folows get a single subs like mentioned about and put it in a ported box ported boxes at +3db of sound so you would gain back the volume lost by going to one sub... then you would only need a 600watt amplifier which means less costly, less power upgrades, and same volume as 2 of those subs in sealed boxes...
well i think i have gotten a little carried away and just kept on going so i well leave you with this and let you chew on it a bit... hope it helps you on your way:)
~Chronos
Halflifehavock13 on 07/1/2004 15:59:21
Thank you so much. I think I might go with the 1 sub and a ported box.
swez on 07/1/2004 17:19:00
Mt 2 centavos... just get 1 4+4 ohm sub for now and use a matched ported enclosure. It will be compact in size and still produce plenty of bass power in that large body SUV.
As for amps, the JBL BP-600.1 Powervalve series amp delivers a true 600 + watts (RMS) to a 2 ohm load. When wiring this sub in parallel to amp, (both Pos terminals to Pos on amp, both Neg terminals to Neg on amp) that's a 2 ohm load.
You can buy a BP-600.1 for about $220.00 at www.sounddomain.com or a bit cheaper off e-bay. This amp is 1 or 2 ohm stable and will draw just under 60 amperes of current at full throttle. Nominal current draw is closre to 30-45A., at loud listening levels.
Here are the specs for this amp:
JBL PowerValve BP-600.1 $219.95 (cheaper off e-bay)
Subwoofer Mono Amp
Subwoofer Mono Amp Specifications
Amplifier Type: Mono
RMS Power: 300W x 1 @ 4 ohms
THD at 4-Ohm RMS Power: 0.1%
RMS Power: 600W x 1 @ 2 ohms
Speaker Level Inputs: Yes
Preamp Outputs: No
Built-In Crossovers: LP
Bass Boost: 0-6 dB
Frequency Response: 10-320 Hz
Signal to Noise Ratio: >100 dB
Fuse Rating: 2 x 30 amps
Shipping Weight: 10.5 lbs
Warranty: 1 year
====================================================
If you do elect to go ported, expect more low end bass, depending on the tuning frequency of the enclosure. This amp does not have subsonic filtering (recommended on ported enclosures) so you can buy a pair of plug & play filters for them as well. Not very expensive either. Can give you a lonk to same, once you know the tuning port frequency of the box you want. Shoot for a tuned port frequency near 30-35 Hz., for best SQL performance.
Swez
PS If you don't wish to make your own sub enclosure, consider Sub Zone. They make very good boxes... not the cheapo 5/8" MDF boxes.. a real 3/4" MDF box for that heavy SPL you will get with this combination.
PSS What HU are you planning to use in this truck?
Replies (5)
Halflifehavock13 on 07/1/2004 11:58:36
I have a 2004 blazer 2 door. I wanted to put 2 12" rockford fostgate T112D2 or T112D4. I dont know which one to go with. What amp would be best for 2 of those subs (and I dont mean what company, but what class amp, wattage and channel)
Halflifehavock13 on 07/1/2004 11:59:12
oops, I was hoping to have a 75/25 SQ-SPL
uochronos on 07/1/2004 15:12:22
alot of info required for this explanation
first off as far as what class amp to get..
for subs we recomend a calss D or class T amp. mone(1 channel) these amps are built for subs and are extremly effecient mening almost all the power they draw from your battery they use to make sound. unles a class A/B which only about 60% of the energy it draws well make sound the rest is just lost in heat.
as far as hooking up 2 subs to a mono amp you well simply wire the 2 subs together in either parelel or series or parrelel/series. and then wire that to your amp. here is a great site that shows you almost all the wioring combinations.
http://www.phoenixgold.com/tutorial/wiring_tutor.html
now for ohmage this one is a bit confusing and took myself awhile to understand it bassicaly your speaker has a set ohmage most car subs have a single 4 Ohm voice coil(VC) , a single 8 Ohm VC, dual 4 ohm VC's, or Dual 2 Ohm VC's,
the 2 you mentioned have dual 2 and dual 4 ohm VC's..
now which you get well matter on was amp you get and howmany subs you get assuming you get a class D amp which most Class D amps are stable at 2 ohms. and you get 2 subs you would want dual 2 ohm subs. and would want them wired as follows
you would take each sub and hook the negitive from one VC to the positive of the other VC. do that on both subs. that well add the Ohmage of each VC and make each sub a 4 ohm load. then you well run the positive that still open on one sub to the positive thats open still on the other and run that to the positive on the amp then you well run a wire from the negitive that hasent been used on onesub the the negitive that hasnt been used on the other sub. then run from there a wire to the negitive on the amp. the second part runs the subs in parrelel which cuts the Ohmage in half neting you a 2 ohm load which is what most class D amps are stable at.
you can refer to the web site i mentioned earlier to get a picture of what wireing like that well look like..
the basic idea behind ohmage is if you run it in parelel positive to positie and negitive to negitive then to amp you well cut the subs ohmage in half. but if you run in series which is negitive to positive and then runing the open positive and negitive to the amp this well double the ohmage from say 4 ohm to 8 ohm.. that web page is really a handy tool since it visualy shows you how to do it and what result it well get you.
so as far as which one of the subs you get it well relie entirly on what amp you get the subs youi mentioned are identical except for the VC ohmage which only changes what amp they well work with.
Ok now for the speaker question you can hook up 4 after market speakers to your HU assumeing it has 4 set of speaker wires.. although a modest amp well help alot with sound quality.
just looked up the subs you mentioned these are some power full subs you want here 600watts rms a piece... you well need a 1200watt RMS amp to power these....JBL makes a good solid amp called the power valve series can usualy be had on ebay for around 250-350$ would work well for your subs. also phonix gold tantrum series can be had for right around 300$ for there 1200watt version off ebay if you shop it well..
I do see one problem that may occur here a 1200watt amp well pull alot of power right around 100amps if turned up all the way around 50-70amps when listening at normal volumes. your stock electrical system may not be able to handle this... i have a 2003ranger which had 110amp alternator stock and a 500watt amp would dim my lights when my headlights and heat was on... a 1200watt amp can easily do that and more... find out how large your stock alternaotr is if its 120-150 you may be alright but if its 120 or less you well need to upgrade or face alot of anoying problems down the road...
or there is a second option get just one opf these subs... you ask wont that be half as loud? no it well not cutting out one subs or droping the RMS wattage in half only lowers the volume 3 DB which is not very much at all... you could even do asw folows get a single subs like mentioned about and put it in a ported box ported boxes at +3db of sound so you would gain back the volume lost by going to one sub... then you would only need a 600watt amplifier which means less costly, less power upgrades, and same volume as 2 of those subs in sealed boxes...
well i think i have gotten a little carried away and just kept on going so i well leave you with this and let you chew on it a bit... hope it helps you on your way:)
~Chronos
Halflifehavock13 on 07/1/2004 15:59:21
Thank you so much. I think I might go with the 1 sub and a ported box.
swez on 07/1/2004 17:19:00
Mt 2 centavos... just get 1 4+4 ohm sub for now and use a matched ported enclosure. It will be compact in size and still produce plenty of bass power in that large body SUV.
As for amps, the JBL BP-600.1 Powervalve series amp delivers a true 600 + watts (RMS) to a 2 ohm load. When wiring this sub in parallel to amp, (both Pos terminals to Pos on amp, both Neg terminals to Neg on amp) that's a 2 ohm load.
You can buy a BP-600.1 for about $220.00 at www.sounddomain.com or a bit cheaper off e-bay. This amp is 1 or 2 ohm stable and will draw just under 60 amperes of current at full throttle. Nominal current draw is closre to 30-45A., at loud listening levels.
Here are the specs for this amp:
JBL PowerValve BP-600.1 $219.95 (cheaper off e-bay)
Subwoofer Mono Amp
Subwoofer Mono Amp Specifications
Amplifier Type: Mono
RMS Power: 300W x 1 @ 4 ohms
THD at 4-Ohm RMS Power: 0.1%
RMS Power: 600W x 1 @ 2 ohms
Speaker Level Inputs: Yes
Preamp Outputs: No
Built-In Crossovers: LP
Bass Boost: 0-6 dB
Frequency Response: 10-320 Hz
Signal to Noise Ratio: >100 dB
Fuse Rating: 2 x 30 amps
Shipping Weight: 10.5 lbs
Warranty: 1 year
====================================================
If you do elect to go ported, expect more low end bass, depending on the tuning frequency of the enclosure. This amp does not have subsonic filtering (recommended on ported enclosures) so you can buy a pair of plug & play filters for them as well. Not very expensive either. Can give you a lonk to same, once you know the tuning port frequency of the box you want. Shoot for a tuned port frequency near 30-35 Hz., for best SQL performance.
Swez
PS If you don't wish to make your own sub enclosure, consider Sub Zone. They make very good boxes... not the cheapo 5/8" MDF boxes.. a real 3/4" MDF box for that heavy SPL you will get with this combination.
PSS What HU are you planning to use in this truck?
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