Amp sub connection question

Amp sub connection question

I just bought another sub which is dual voice coil and am going to install it onto my current amp with my other sub. My amp is a 2 channel amp which is only running to one sub right now. plan on bridging the amp to 4 ohms which is 800 x 1, then im going to either wire them in parralell or a series. These are the diagrams i found

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So what im thinking after looking at this iss bridging my amp to 800W x 1 then parralelling it and they are both going to be at 4 ohms but it makes them 2 ohms by doing this and each get 400W x 1.

Is this a good idea and does this diagram look like what i should do? Ive been reading about it and from what it looks like parralell looks like it will be good, or i can put them each one on channel and each will get the same 400 w at 2 ohms but also from what i was reading doing that doesnt produce as great of results as bridging.

Anyways im going to try one of these out tommorow, please let me know if this is the best way to do this.[/img]

what is the impedance of each voice coil of the sub you just got, and what is the impedance of the sub you already had? And is the old one DVC also? If they cant both be ran at the same impedance then one sub is going to get more power and be louder than the other.. of course that might happen naturally anyways since they are different subs with most lilely different efficiencies.

Heres some advice on amps though.. Almost all 2 channel amps put out the same amount of power bridged when running at 4 ohms, as they do non bridged when each channel is running at 2 ohms.. So it probably wont matter which way you do it..
for instance an amp that is 400 watts x 1 at 4 ohms is usually 200 x 2 @ 2 ohms..
One more thing, If both subs are in the same box and are not in separate chambers, then you want to bridge the amp and run one channel to the subs because in stereo the separate channels may cause cancellations.

Unfortunately most amps dont want you to bridge them and run at 2 ohms.. However, i had my mtx amp hooked up like that for a long time and it never died.. it looks like thats not a possible configuration for your setup anyways.. You could probably get another amp and run it at 1 ohm..

Ok i found out they are nominal at dual 4 ohms which i dont really know what that means. I set it up on 2 channels and they sounded crappy, i also set them up bridged at 8 ohms each which supposidly brings them to 4 ohm load and it sounds crappy still, so if i set them both at 4 ohms would it be safe or not, i dont think it can even be bridged down to 2 ohms it says 4 ohms 1x800watts bridged. I might not have some of this right i am just learning audio stuff what do you suggest i do?

Well did your subs sound crappy to begin with?? what kind of subs are they? and also, what do you mean by crappy? Does that mean lots of distortion or are they just not very loud? Many times problems with how subs sound is when you have a shitty box with leaks..

More power wont really give you better sounding subs, just louder subs.. 400 watts a piece should make just about any speaker move quite a bit.. I know tons of people out there are pushing subs with 1000+ watt amps, but the difference between the two is just a few decibals of loudness, thats if your amp is truly pushing out 800 watts though.. cheaper brands of amps are usually overrated.. more expensive amps are generally underrated.

I wouldnt run the subs at 2 a 2 ohms load unless you really think it will help a lot, because your amp could take a crap on you if you do.. I ran my amp bridged at 2 ohms for like 6 months or so and it never died though, but its your call.. It will probably be a bit louder but you'll also get more distortion, so if they already sounded crappy this isnt gunna help.

Also one last thing I just remembered.. One time i wired my subs out of phase and they had almost not loudness at all and they sounded really crappy.. Check that you have them wired correctly because if they are wired out of phase you will get tons of cancellations and it wont sound right at all.

Ok i had a single bandpass box before which had 2 port holes and it had my one 12 in it with the 800 watt amp running to just it and it sounded really loud. Now i bought a dual bandpass box with 4 port holes in front and it doesnt hit hardly at all, my rear view mirror used to move with my old one and with this one it doesnt move at all barely. I was thinking i just need more power because the amp isnt pushing enough for 2 of these. My amp is 150w rms x 2 at 4 ohms so its like 300 rms right now, which means each are getting like 150. 150 watts to a 1200 watt sub isnt all that much and to put them in a bandpass box i dont think is enough but i dont know. Is it better off to just get a new box or what, i paid like 70 bucks for the damn thing so it kind of pisses me off. I was thinking of getting the brutus you suggested but i want to figure out what the problem is before hand. Also one other thing, does it matter much if the subs are screwed in snug with the box, because i had to do some modifying with my dremel to fit them in and right now they still arent against it tight. Oh and would the gain matter, should i mess around with that, it was set up for a single sub not 2 so i didnt mess with it. Thanks for your help.

Problem solved! I went ahead and ran them both at 4 ohms so they are running at 2 ohms bridged at 800 watts which isnt recommended for my amp but considering its a boss amp i dont give a damn. So the whole problem is my amp is a piece of crap, but now that i went ahead and ran it at 2 it is running great and loud again. Thanks for all the help subwoofy i appreciate it greatly.

all this stuff is a foreign language to me but i wanna ask about the wiring of a dual coice coil speakers which is the best way to have it
i have 2 12" rockford he2's wit and 1800 rockford amp
i'm tryna learn this whole ohms thing but it's got me a lil confused can u guys help me out

i would recommend starting a new thread for this question..

It depends how many ohms the coils are and how many ohms the amp will run at.. If they are dual 4 ohm coils then you can run the set at either 16, 4 or 1 ohm.
your amp most likely wont run at 1 ohm since i dont think any rockford fosgate amps do (at least they dont recommend it)

In series the resistance (impedance in this case) can be calculated by adding the resistance of each coil. therefore if you wired the coils of one subwoofer in series it would be running at 8 ohms. If you ran them both in series, and in series with each other, they would be at 16 ohms..(dont do that, you wont get hardly any power out of your amp).

on the other hand, in parallel the impedance is a little harder to figure out.
1/r = 1/r1 + 1/r2 +...

if you have two speakers you can just divide the resistance of the coils by two.

if you have two 8 ohm subs in parallel they will be 4 ohms..

http://www.crutchfieldadvisor.com/ISEO-rgbtcspd/learningcenter/car/subwoofers_wiring.html