matching amps w/ subs
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=44853
Printed Date: May 25, 2025 at 2:33 AM
Topic: matching amps w/ subs
Posted By: Xplorer
Subject: matching amps w/ subs
Date Posted: December 09, 2004 at 11:59 PM
bandpass enclosure with 4 tuned ports two 4-ohm 12" Visonik spruce-pulp paper woofers two speaker inputsrecommended power range 80-600 watts RMS (each sub 300 RMS max)sensitivity 93 db I am looking for a single amp to power these two subs and i want them to hit, but i want the amp to match the capabilites of the subs. Thanx ------------- Peace
Replies:
Posted By: stevdart
Date Posted: December 10, 2004 at 12:16 AM
What is "RMS max"? Find out and post the RMS rating of those woofers. Max rating is meaningless.
Posted By: wheelerdr
Date Posted: December 10, 2004 at 2:06 AM
I would go to locustaudio.com and get a keenwood excelon 811d for 235 + s/h great amp you will have to turn the gain down a lot but this gives you lots of room for improvement on your subs if you want to upgrade later. this amp will do 500 at 4 ohms, 900@ 2 ohms and 1000 @ 1ohm. It is a class d and very efficent amp. great deal for the money.
Posted By: Xplorer
Date Posted: December 10, 2004 at 10:34 AM
each sub is 80-300 RMS
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Peace
Posted By: Xplorer
Date Posted: December 10, 2004 at 4:56 PM
Wheeler ... no where does it say 500 @ 4 Ohms and what exactly am i looking for in an amp... 500x2@4Ohms@ 12v? ------------- Peace
Posted By: bullman96
Date Posted: December 10, 2004 at 5:05 PM
you would wire the subs in paralell to make them 2 ohms. the amp will put out 900rms at 2ohms. just be sure not to blow the subs(use a dmm to set the gains so the amp is only putting out 600rms), though that wouldnt be a bad thing. the amp will leave you some room to get some decent subs in the future
Posted By: kfr01
Date Posted: December 10, 2004 at 5:28 PM
Go with a mono amp that puts out 300-500w total rms at 2ohms. Anywhere in there is fine. You'll also want to use a subsonic filter .. either from your head unit or a harrison labs f-mod.
Try this for the amp: https://www.cardomain.com/item/MTX421D
Decent deal on a very solid amp.
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New Project: 2003 Pathfinder
Posted By: Xplorer
Date Posted: December 10, 2004 at 8:34 PM
So then an amp with a rating of around 600X1@2Ohms would be perfect for these subs right? I have a LPF of 125 and 75 in my head unit...is that good enough for a filter? ------------- Peace
Posted By: kfr01
Date Posted: December 10, 2004 at 9:43 PM
No, you'll also want to run a subsonic filter. https://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=266-248 No, I told you, 300-500w is what I'd shoot for for those subs. That boombox is undoubtedly highly overrated and in a bandpass enclosure. Bandpass enclosures reduce the power handling capability of subs. Also, doubling the amplifier power only gives a 3db increase in spl. So, moving from 300w to 600w only gives you 3db more SPL. 3db is not large. That MTX amplifier I linked would be perfect for those subs. I highly doubt you'd hear ANY difference between that MTX amp at ~400w and a 600w amplifier. Don't stress out about matching ratings. It simply isn't that important. ------------- New Project: 2003 Pathfinder
Posted By: Xplorer
Date Posted: December 10, 2004 at 10:40 PM
OK...for the subsonic filters why did you choose the 30hz High Pass filters and what does that mean exactly. What does it mean if an amp has preamp outputs? Also why the MTX amp w/420W @ 2 Ohm (@CarDomain)...why not the Coustic 600DB?(its $50 cheaper, has a built in 30hz subsonic filter like you talked about, and remote bass boost)...or the Boss Chaos C1200? (its $60 cheaper and has more power)...or the Riot 850 (its $150 cheaper! and the same power)? Its alot of questions but im just picking ur brain here. Thank you again. ------------- Peace
Posted By: kfr01
Date Posted: December 10, 2004 at 11:31 PM
You have a bandpass box. These boxes create a frequency region "bandpass" where the SPL output is very high. However, above or below this region the output drops substantially and when the subwoofer tries to create ultra low frequencies, those below the lower tuning frequency of the box, it will distort, bottom out, sound like ass, whatever you want to call it. A 30hz high pass filter will start substantially taking out the frequencies below 30hz. Since your subwoofer won't try to reproduce these low frequencies it has a hard time with, your bass will sound better playing what your box was meant to play. Well, the MTX amp probably actually puts out what it says it does. MTX is made by the same company (Mitek) as Coustic. Coustic is the "value" brand compared to MTX. Within that company the brand hierarchy goes Coustic < MTX < Xtant. Coustic is better than Boss or Riot, but either way the MTX is going to be more honestly rated, tough, clean, and long lasting. It is simply a better amp than those others. Trust me, it is not worth going with a cheaper amp that "says" it does 600w or 850w. ------------- New Project: 2003 Pathfinder
Posted By: Xplorer
Date Posted: December 11, 2004 at 11:59 PM
Any thoughts about a Hifonics Brutus BX1000D? ------------- Peace
Posted By: kfr01
Date Posted: December 12, 2004 at 12:08 AM
Way more power than you need for that sub/enclosure combination. ------------- New Project: 2003 Pathfinder
Posted By: Xplorer
Date Posted: December 13, 2004 at 2:49 AM
if i could get it cheap should i do it or is it too much?
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Peace
Posted By: kfr01
Date Posted: December 13, 2004 at 10:49 AM
I'd look for a better amp for those subs, but sure, just don't be an idiot with the gain or the volume.
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New Project: 2003 Pathfinder
Posted By: Xplorer
Date Posted: December 13, 2004 at 4:12 PM
when you say a "better" amp for those subs do you mean to say that the Brutus isnt any good or do you mean to say find an amp that is"better" suited (in power etc.) for those subs?
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Peace
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