Sponsored links

Go Back   MP3Car.com > Mp3Car Technical > Car Audio


Reply
 
Share Thread Tools Display Modes
Old 12-27-2008, 11:16 PM   #1
Newbie
 
ph7ryan's Avatar
 
Join Date: Dec 2008
Location: Atlanta
Posts: 54
ph7ryan is an unknown quantity at this point
Ohms question

Ok...so I think that I am getting a hold on how all of this works....

I am definitely buying 2 KDC-W3011's no question...and I want to stay low in the price, so i think im going with a MD 2622...

The problem...

The Amp runs at 2 ohms, and the subs require 4 ohms...

Now I know that ohms are resistance, and that less ohms means more power, so more power from the amp to the subs will not be good I don't think...I DO NOT WANT TO BLOW ANYTHING...AT ALL ...So I know that resistors can increase the number of ohms, but I would like to make this as simple as possible...

any help would be greatly appreciated...
ph7ryan is offline   Reply With Quote
Advertisement
 
Advertisement
Sponsored links

Old 12-28-2008, 04:00 AM   #2
Variable Bitrate
 
rgarjr's Avatar
 
Join Date: Jan 2008
Location: Covina, CA
Posts: 416
rgarjr is an unknown quantity at this point
amp can run at 4ohms. if u have 2 subs, hook them in parallel so they will be 2 ohms.
__________________
My carpc worklog
rgarjr is offline   Reply With Quote
Old 12-28-2008, 09:22 AM   #3
Newbie
 
ph7ryan's Avatar
 
Join Date: Dec 2008
Location: Atlanta
Posts: 54
ph7ryan is an unknown quantity at this point
Quote: Originally Posted by rgarjr View Post
amp can run at 4ohms. if u have 2 subs, hook them in parallel so they will be 2 ohms.

wait so you can set the amp to run at 4 ohms.... and i meant that each sub is 4 ohms, not that both subs together would equal 4 ohms....

sorry if i misunderstand you, but i (very amateur at this) am seeing what you are saying as if they are both on the same signal, then they would only need 2 ohms (if the subs were each 2 ohms)...but the subs are each 4 ohm subs....

Thanks for your help...a lot.....I hate when i post and no one even posts back...
ph7ryan is offline   Reply With Quote
Old 12-28-2008, 09:32 AM   #4
Newbie
 
ph7ryan's Avatar
 
Join Date: Dec 2008
Location: Atlanta
Posts: 54
ph7ryan is an unknown quantity at this point
oh...well stupid me decided to reply without doing research, so now I understand what you are talking about with it decreasing the ohms, because it will be a 2 ohm load....gottcha...but because my amp is a 2 channel, and I will be running only one channel to both subs, would it be bad to bridge the connection...sorry if it is a stupid question...just want to get the most out of what I buy


Thanks again
ph7ryan is offline   Reply With Quote
Old 12-28-2008, 09:50 AM   #5
Newbie
 
ph7ryan's Avatar
 
Join Date: Dec 2008
Location: Atlanta
Posts: 54
ph7ryan is an unknown quantity at this point
i understand what you are saying... parallel will make a load of 2 ohms....thanks....

One more question....If the amp is 2 channels, but I am only using one signal (because the subs will be parallel) would it be ok to bridge the connection between the amp and the first sub....if not, what would be the best way to get the most power out of my subs...should I go for another mono amp, and have a higher wattage....


thanks....
ph7ryan is offline   Reply With Quote
Old 12-28-2008, 10:37 AM   #6
Constant Bitrate
 
scatebase's Avatar
 
Join Date: Oct 2008
Posts: 144
scatebase is an unknown quantity at this point
Crutchfield has a nice section that spells this out pretty well:
http://www.crutchfield.com/learn/lea...rs_wiring.html
__________________
xb_mini
scatebase is offline   Reply With Quote
Old 12-28-2008, 10:56 AM   #7
Newbie
 
Join Date: Jan 2008
Posts: 23
daveczrn is an unknown quantity at this point
the amp says it's only stable at 2ohms in stero. meaning you shouldn't bridge the amp down to one channel. I don't think you have even thought of doing this but the subs look like they might be able to handel it. As far as both the subs and amps saying they will handel 1200watts peak. don't expect to hear anything close to that.

I personally have never herd of the MDsound name. But i have been out of the game for some time. For the price i know power acoustik has been around for much longer and they have always had alright amps that hit pretty hard. the ov2-1250 would be my choice for a model in that price range. It is rated to output a higher wattage and there are rating of it bridged as well. But with higher wattage you have the chance of blowing a speaker... so it's your call.
daveczrn is offline   Reply With Quote
Old 12-28-2008, 10:57 AM   #8
Constant Bitrate
 
scatebase's Avatar
 
Join Date: Oct 2008
Posts: 144
scatebase is an unknown quantity at this point
It looks like your subs are 400w RMS a piece. When looking at speakers and amps, you want to know the RMS power. This is the level that the amp and subs can sustain. The 1200w you saw was peak level, which would probably never be reached on a generic amp.

I know that you wanted to save money on your amp, but you would be better off if you got a better quality amp with less advertised power(but more actual power). This mono amp is rated at 800w RMS at 2 ohms, but 2400 peak. It's $300, but it is an investment that should last longer than your subs if you take care of it.
__________________
xb_mini

Last edited by scatebase; 12-28-2008 at 11:01 AM.
scatebase is offline   Reply With Quote
Sponsored links
Advertisement
 
Advertisement
Old 12-28-2008, 11:01 AM   #9
Constant Bitrate
 
scatebase's Avatar
 
Join Date: Oct 2008
Posts: 144
scatebase is an unknown quantity at this point
Even though you have 2 subs, you can still use a mono amp. You will get more out of your amp this way.

2 ohm stable means that you can go as low as 2 ohms. I don't think I have ever seen an amp that can't do 4 ohms(higher is easier).
__________________
xb_mini
scatebase is offline   Reply With Quote
Old 12-28-2008, 06:02 PM   #10
Newbie
 
ph7ryan's Avatar
 
Join Date: Dec 2008
Location: Atlanta
Posts: 54
ph7ryan is an unknown quantity at this point
Quote: Originally Posted by daveczrn View Post
I personally have never herd of the MDsound name.

Ya neither have I...but I read some reviews on the product, and people were saying how they were shaky at first cause of the no namer title, but it is a hell of an amp for the cheap price..so....

and...ok...so I should look for another amp....

And ya i def need to stay in the $100 range....so those other amps are out of the question...

has anyone heard of Lanzar audio....they have some way over rated ratings, but I would like to know how good they really are...

Thanks for everyones help btw
ph7ryan is offline   Reply With Quote
Old 12-28-2008, 08:40 PM   #11
Newbie
 
ph7ryan's Avatar
 
Join Date: Dec 2008
Location: Atlanta
Posts: 54
ph7ryan is an unknown quantity at this point
is there a way to tone down RMS for an amp...cause what if I got this


http://www.woofersetc.com/index.cfm?...product_id=484

it says that at 4 ohms, with each channel, it puts out 500 RMS, but the subs are each only 400 RMS...will this extra 100 RMS make a difference....is it hard to fix....

Thanks
ph7ryan is offline   Reply With Quote
Old 12-28-2008, 09:03 PM   #12
Maximum Bitrate
 
FusionFanatic's Avatar
 
Join Date: May 2007
Location: Boston
Posts: 789
FusionFanatic is an unknown quantity at this point
have you bought anything yet? what's your total budget (for both subs AND amp)? and where are you planning to buy from?

the prices range quite a bit for those subs. overstock.com (the first google result) sells them for $129 each, while sonicelectronix.com sells them for $39 each. that kind of savings will leave with more money for a better amplifier

there's no point in buying nice subs only to power them with a garbage amplifier. take everything into consideration when planning your install, don't cheap out on 1 component and think it won't matter. don't limit the amount of money that you can spend on just the amp, limit the amount of money you can spend on the entire system. in other words; if you spend 75% of your budget on subs then you won't have enough money leftover to buy an amp good enough to power them adequately and efficiently.

consider using 1 sub instead of 2 if that saves you enough money to get a better amp. you'll get better sound out of a single sub with a good amp then you will out of 2 subs and a garbage amp. stay away from the typical garbage brands like Lanzar, Legacy, Pyle, Pyramid, etc.

remember, you can't go by peak/max wattage ratings. only pay attention to RMS ratings (if the manufacurer doesn't state the RMS output then don't even consider buying the amp). and even if they do, if it's a crap company then you still can't expect the amp to produce it's RMS rating either. only buy reputible brands, if money is very tight then check out eBay or craigslist for used/refurb amps.

the only site I could find that lists the RMS output for that MD2622 amp states 120w x2 @4ohms, 150w x2 @2ohms, or 300w x1 @4ohms. those specs are shady at best. normally, when you cut the impedance in half you double the amplifier power output. with that amp you only gain 30 more watts? hmmm...

I use a Kicker ZX400.1 400w RMS mono amp to power a single 10" Infinity kappa (that amp can handle more than that, but I'm long since out of high school and have no need for earth shaking bass anymore. I used to use it to power two 12" MTX Blue Thunder Legends and it handled them with ease). Kicker is one of the few amplifier manufacturers that actually under-rates their power output specs. my ZX400.1 was "tested" at the factory and came with a certificate stating that it will produce 429w RMS (that's 29w more than it's rated for ). I bought the amp on eBay for about $100. I'm not saying you need to buy this amp, byt I use one myself so I can recommend it for it's price, size, and quality. it is half the size, more effeicient, and will output more power than the MD2622 amp you were looking at.

whatever you decide, good luck
FusionFanatic is offline   Reply With Quote
Old 12-28-2008, 09:07 PM   #13
Constant Bitrate
 
scatebase's Avatar
 
Join Date: Oct 2008
Posts: 144
scatebase is an unknown quantity at this point
I completely understand your point about the price, but I think it would be worth the extra money, even if you went with a less powerful amp.
__________________
xb_mini
scatebase is offline   Reply With Quote
Old 12-28-2008, 09:16 PM   #14
Constant Bitrate
 
scatebase's Avatar
 
Join Date: Oct 2008
Posts: 144
scatebase is an unknown quantity at this point
Everything that FusionFanatic said was beautiful.
__________________
xb_mini
scatebase is offline   Reply With Quote
Old 12-28-2008, 10:08 PM   #15
Newbie
 
ph7ryan's Avatar
 
Join Date: Dec 2008
Location: Atlanta
Posts: 54
ph7ryan is an unknown quantity at this point
Quote: Originally Posted by FusionFanatic View Post
have you bought anything yet? what's your total budget (for both subs AND amp)? and where are you planning to buy from?

the prices range quite a bit for those subs. overstock.com (the first google result) sells them for $129 each, while sonicelectronix.com sells them for $39 each. that kind of savings will leave with more money for a better amplifier

there's no point in buying nice subs only to power them with a garbage amplifier. take everything into consideration when planning your install, don't cheap out on 1 component and think it won't matter. don't limit the amount of money that you can spend on just the amp, limit the amount of money you can spend on the entire system. in other words; if you spend 75% of your budget on subs then you won't have enough money leftover to buy an amp good enough to power them adequately and efficiently.

consider using 1 sub instead of 2 if that saves you enough money to get a better amp. you'll get better sound out of a single sub with a good amp then you will out of 2 subs and a garbage amp. stay away from the typical garbage brands like Lanzar, Legacy, Pyle, Pyramid, etc.

remember, you can't go by peak/max wattage ratings. only pay attention to RMS ratings (if the manufacurer doesn't state the RMS output then don't even consider buying the amp). and even if they do, if it's a crap company then you still can't expect the amp to produce it's RMS rating either. only buy reputible brands, if money is very tight then check out eBay or craigslist for used/refurb amps.

the only site I could find that lists the RMS output for that MD2622 amp states 120w x2 @4ohms, 150w x2 @2ohms, or 300w x1 @4ohms. those specs are shady at best. normally, when you cut the impedance in half you double the amplifier power output. with that amp you only gain 30 more watts? hmmm...

I use a Kicker ZX400.1 400w RMS mono amp to power a single 10" Infinity kappa (that amp can handle more than that, but I'm long since out of high school and have no need for earth shaking bass anymore. I used to use it to power two 12" MTX Blue Thunder Legends and it handled them with ease). Kicker is one of the few amplifier manufacturers that actually under-rates their power output specs. my ZX400.1 was "tested" at the factory and came with a certificate stating that it will produce 429w RMS (that's 29w more than it's rated for ). I bought the amp on eBay for about $100. I'm not saying you need to buy this amp, byt I use one myself so I can recommend it for it's price, size, and quality. it is half the size, more effeicient, and will output more power than the MD2622 amp you were looking at.

whatever you decide, good luck

YES!...thankyou....if there is a rating members feature on this forums then please point me to it so that I can give you the best one possible....buying those subs cheap would be great, because I am planning on trying to stay around $500...$600 absolute max...That will definitely clear some space for a higher quality amp...I also really would like to use a xovision 7" touchscreen H/U, which is $200 from walmart (usually $268), plus I would like 2 of the kenwood subs, and the wires would cost a good bit also....

I have not bought anything for the system yet, and probably will not for a good while...months maybe...but I would like to just have a shopping list of exactly what to buy from where and how much so that when I do get everything, there will be minimal issues, and I can focus on the install and box building....

Many people say that a system should be heard not seen...i say why not both...

I am planning on buying a rather eye appealing "wall" for say, and will probably go with a sealed box for each sub....but I plan on mounting them inverted because I love the way they look and think that the KDC-W3011's would look sick inverted, and with the great ratings from customers, and very low cost, I figure that I cannot go wrong....

Thank you all so much...Words cannot describe how godly smart you guys are...
ph7ryan is offline   Reply With Quote
Sponsored links
Advertisement
 
Advertisement
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
dual vioce coil sub/amp wiring hotponyshoes Car Audio 32 12-24-2007 01:20 AM
Any in-dash monitor with built in FM Radio QUESTION. ??? 74Camaro LCD/Display 2 05-02-2006 06:15 PM
Ohms, Watts, speakers & AMPs - confused kingtut Car Audio 41 07-15-2005 06:40 AM
speaker connection question modh1984 Car Audio 1 05-24-2005 01:27 PM
FM Card Question.... Superbike1k Car Audio 1 05-16-2005 10:03 AM



All times are GMT -5. The time now is 01:43 PM.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2009, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO 3.3.2
Copyright © 1999 - 2008 Mp3Car.com Inc.Ad Management by RedTyger
Message Board Statistics