Dual 4ohm to 4ohm load?

Ok, it sounds like you do know what a 2 ohm load is when bridged as well as in stereo.  But just for the record, can you tell us how you have the subs connected to the amp.  You said it was bridged, and you said it was a 2 ohm load when bridged.  So you must have the two subs wired in parallel with each sub's positive connected together and each sub's negative connected together as well and then that combination bridged to the amp. 

Also you said it was a 460 watt RMS amp bridged into a 4 ohm load.  But right now you have a 2 ohm load bridged to this amp.  Then you should be getting a lot more than 460 watts RMS.  Close to double this amount. 

Now I'm not saying that this should sound good but why do you want to change this??  You cannot get anymore power from that amp by wiring any other way, and especially not by wiring to higher ohm loads(that would bring it down).  And you said that the amp is stable when bridged into 2 ohms and does not run hot so it should be doing fine.

But you also said that it does not run as high powered as you want it to.  What is it that makes you say this??  Are you hearing distortion and bad sound??

I'm afraid that without changing subs or amps(one or the other) then the only way for you to get a 4 ohm load bridged to this amp is to just use one sub only.  That will get you the 4 ohm load and only the 460 watts RMS, and may even sound better if the other set up is distorting badly. 

Post again to say what it is that makes you think you need to change your set up.

but when ever it talks about any load at 2 ohms its always with two chanels never a mono nor a bridged output: Power Output at 2 Ohms, at 14.4V (1kHz, 0.8% THD): 230 Watts x 2

Twofoot, the owner's manual only talks about a 2 ohm load in stereo with two channels, and not in mono because the amp is not rated to handle a 2 ohm load when bridged.  The amp being wired for a 2 ohm load and bridged is exceeding it's capacity.  You said earlier that it was running cool and was rated to handle this, but what you posted above states that it shouldn't be used this way. 

I would run one sub per channel to protect the amp.  I am not there and cannot possibly know how cool the amp actually is running, nor if it is distorting or not, but I just wouldn't do what you are doing.

I can't find a reference on Alpine SWE 1241 to verify that it is a DVC 4 ohm sub, so this is assuming that your post title is correct.  (Two 4 ohm DVC's cannot equal a 2 ohm load.)   You have two 4 ohm DVC subs and a 2 channel amp.  You can connect the subs separately to the amp, a sub to each channel, like

.....OR, you can connect the subs together first, and then connect to the amp bridged, like

You'll notice the coils of the subs are wired differently from pic 1 to pic 2.  But the important thing to know is that either way you do it, the amp gets the same impedance load and puts out identical power .  Either way.

So how do you choose which way to do it?

Take the overall install into consideration...the subs share the same enclosure, and sub freqs do not need to be played in stereo.  Both of these points  go to the bridged way of thinking.  Also, there will be less speaker wires to hide, a point also going to the bridged argument.

In fact, there is no reasonable argument to connect the two subs in stereo.  So, quite naturally, I would bridge to the amp wired as shown in pic 2.

So, new testimony.  My same argument above applies to this

Same as 4 ohm stereo, neater install.

Bridging is the act of connecting two amplifiers.  A two channel amp is in fact two mono amps.  The load, when bridged, goes half to one amp and half to the other amp...so a 2 channel amp gets 4 ohm per channel in this case.  The reasons I would bridge instead of connecting each sub to a channel are listed in my first post:

Take the overall install into consideration...the subs share the same enclosure, and sub freqs do not need to be played in stereo.  Both of these points  go to the bridged way of thinking.  Also, there will be less speaker wires to hide, a point also going to the bridged argument.

Another reason that sometimes applies is that you will get a more impactful bass response if both subs are getting the same mono input, rather than one getting left and the other getting right signals.

OK you said your amp was 230 x 2 at 2 ohms.  That's stereo.  At 4 ohms stereo, it will be 1/2 of that per channel.  It will be 115 watts x2 at 4 ohms.   

It should be 460 watts x 1 at 4 ohms.  If you show it an 8 ohm bridged mono load, then that is going to cut that 460 watts in half, for 230 watts total when bridged.  And each sub is only going to get 1/2 of that, for 115 watts per sub.  That's the same as it would have been in stereo.  But you have each sub getting the same exact signal instead of a right and left channel(cause they are different in some ways).  And you have a neater install with just one set of wires going back to the amp instead of two sets. 

Good call stevdart. 

but are you sure that it will be ok for my amp? 

It's not typical to use higher ohm loads in car stereo, but the higher the ohm load the easier it is on the amp...but the lower the output.  The manual specs usually call for a load from 2 to 8 ohms per channel, but don't give details about every possible way  of connecting to your speakers.

Yours is just a situation where the subs you have are not ideally suited to be run with a two channel amp for full power capabilities.

OK THEN....NOW THIS ISN'T REALLY THAT HARD!

You can hook up the speakers in series and just use a 2 ohm resistor(high wattage). You can always add resistance so you dont overheat your amp. And just incase you were wondering, you can buy resistors that will take a few thousand watts....i mean seriously...did this really have to take up 3 pages?!

Bestbuy577 wrote:

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im not one of those guys who just sits there all day and telling people what should work,

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Obviously your job is to decide how many pages a thread can take up.  Now you have evidently decided that this thread should be lengthened, when all was already said and done.  Good job, fella.  And that's some smart thinking about using resistors............(groans)

Two SWE-1241 Alpine Type E's in a box (dont worry about the box its covered) I have them powered by a KAC-7201 Kenwood 800 watt max (460Wrms) at four ohms. But where I run into a problem is at the present moment is, I have them bridged at 2 ohms which sucks at 460 watts max because its at 2 ohms, I need two 4 ohm subs bridged on a amp at 4 ohms..... somehow. So I need some help in doing so, does anyone know a reasonable way of doing this task?
Thank you.

All this is at 14.4 volts so you will get less than this.

The Kenwood KAC-7201 800 watt max pushes

»150 watts RMS x 2 at 4 ohms

»230 watts x 2 at 2 ohms

» 460 watts RMS x 1 bridged output at 4 ohms

» stereo or bridged mono output

» 4-ohm stable in bridged mode

The Alpine SWE-1241 Type E's

»Impedance 4 ohms

»frequency response 26-1,000 Hz

»power range 50-200 watts RMS

»peak power handling 600 watts

First the amp is not 2ohms stable when bridged. For the 2 channel amp to be 2ohms stable when bridged it has to say ??? watts x 2 at 1 ohms. Bridging is running both the channels together. So when you bridge 2ohms and 2ohms you get 4 ohms. Some amps will work bridge @2ohms but it‘s not stable. Some times they get to hot and burn up. I have had my amp @2ohms bridged and I have not had any problems with it. The amp does not even get warm. Not to say every amp will work this way because I have fried a few in the past.

You have two 4ohms subs wired parallel, so the amp will see a 2ohms load. So the subs should be getting around 460 watts between them. 230 watts each sub although that is over the recommended RMS watts you should be ok. More subs blow from clipping than over powering them. So you should keep the amps gains less than ¾ and the head unit less than ¾ and you should be ok.

You have your amp doing all it can do and more than the manufacture

Recommends. You can’t get any more out of the amp. If it work @2ohms bridged and does not get hot run it that way.

Bestbuy577 wrote:

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Oh, im sorry fot having years of experience under my belt....i dont just read sh*t online...i have almost all REAL WORLD experience...im not one of those guys who just sits there all day and telling people what should work, or at least thats what the site/book says....websites arent always right...either are books....and i've also had some problem with metra mislableing their wires...so i do know what im talking about...and it doesnt use half the power of the amp...geeze...alot of big name brands do the same thing...like audiobahn for example

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