# Am I screwed or you think this will work?



## LethalAudio (Feb 12, 2003)

Ok, here's the thing, I am so stressed on the design and wiring of system, I can think right cuz my mind is clouded. Somone tell me if this sounds right.
Ok, here's the specs on my 800a4
- RMS continuous power per channel, both channels driven into a 4ohm load - 100watts x 4
- RMS continuous power per channel, both channels driven into a 2 ohm load - 200watts x 4
- RMS continuous power mono into a 4ohm load - 400watts x 2

The subs Im using are SVC 4 ohms...i want 2 subs on each bridged channel...tell me, if i bridge it in mono and stick two 4 ohm subs on it, is it going to be right? im goin for the 3rd setup...and ill tell ya, i cant think straight enough to do any of these calculations right now...i have this massive hedake..somone please tell me this is right and that im not screwed...cuz i really really dont want to have to buy new 8ohm subs.
___
+ \_________________
___/ \ \ 
+ +
4ohm sub1 4ohm sub2
___ - -
- \_______/__________/
___/

does this even look close to being right? or is that a 2ohm load?


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## sr20dem0n (Mar 19, 2003)

the way I would do it is connect the + from the right front to the + on sub a, then the - from the right rear to the - on sub a. Then the + from the left front to + on sub b, and - from left rear to - on sub b. This way you are running each bridged channel into a 4 ohm sub, and it should give you that 400x2 that you were shooting for.


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## LethalAudio (Feb 12, 2003)

dang that drawing got screwed why the hell did it do that..oh well..thanks for that info...i was gettin so pissed i saw my skin turnin green. thanks for that info, its a much welcome relief.


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## LethalAudio (Feb 12, 2003)

h/o i just read over it again...let me make myself clearer this time....im using 4 200watts RMS(400 peak) subs, all of them 4ohms...i need 2 subs on each bridged channel and i need them to total a 4 ohm load on each bridged channel...*sigh* am i makin any sense or should i take a nap and come back later when im less stressed?


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## LethalAudio (Feb 12, 2003)

wait a minute what if i put them on a bridged channel at an 8ohm load....i mean, when they put in the book that it was stable down to Xohms, does that mean the LOWEST possible impedance that the amp is stable and that anything over that is ok?


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## LethalAudio (Feb 12, 2003)

nevermind, ive been doing research and it looks like im screwed....im going to have to sell all that s**t and get some 8 ohms unless i over looked something


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## sr20dem0n (Mar 19, 2003)

oohhh it makes more sense now, I thought you had 2 4 ohm subs....anyway yes when it says an amp is stable down to say 2 ohms, that means that anything 2ohms+ is alright, meaning you could run it at 8 ohms and be fine. Keep in mind though that if you run them at 8 ohms you will get less power going to each. How low can the amp go?


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## LethalAudio (Feb 12, 2003)

man, i am so stressed right now it isnt funny, my eyes hurt and so duz my brane. Ive been on here for about 3 hours tryin to find an alternative to selling them for 8ohms.....but enough of my whining.
Stable into: (each channel) - 2ohm
Stable into: (bridged/mono) - 4ohm
correct me if im wrong, but if i do the 3rd setup with it at 8ohms, then its really no different than doin the first setup cuz they still get 100wattsRMS each dont they? i have an amp thats suppose to go with them, but its only a 2 channel....anyone wanna buy an amp and 2 subz? lol


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## xt_out (Jun 23, 2003)

dang lethal, you do sound stressed  good luck


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## nastynissan (Jan 26, 2003)

Lets see if Ive got this right..... 4 channel amp.... Single Voice Coil subs.... so you take 
2Channels and Mono Bridge + 1 4ohm Sub =4 0hm load
so we get 
4 Channels Bridged to 2 (mono) + 2 4 ohm subs = 4 ohm load
4 Channels Bridged to 2 (mono) + 4 4ohm subs (2 on each channel wired parallel) = 2 ohm load OR

4 Channels Bridged to 2 (mono) + 4 4ohm subs (2 on each channel wired series = 4 ohm load.

So to run a 4 channel amp in a 2 channel 2 ohm setup will require either 4 subs or 2 DVC subs.

I think thats right..LOL Its too damn early. Hope this helps


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## nastynissan (Jan 26, 2003)

$%IT just read the other posts......
SO to run the amp in 4 ohms you will have to run 2 Subs or get 8 ohm subs.... UNLESS you wire the subs in SERIES.... If you wire 2 4ohm subs in Series you sstay at 4 ohms..... ***** YES There we go the Brain has awakened******** So 4 4ohm subs as 2 pairs each 2 wired in series and hooked to a 4 channel amp bridged into 2 Channels...... Houston we have a 4ohm load......

Personally though Id try wiring them parallel and running the amp into and 2 ohm bridged load... as long as you have adequate power and the amp doesnt get hot you should be alright... and The subs will sound better.... But I no longer use anything that wont handle a 2ohm or lower load....


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## sr20dem0n (Mar 19, 2003)

nastynissan said:


> *$%IT just read the other posts......
> SO to run the amp in 4 ohms you will have to run 2 Subs or get 8 ohm subs.... UNLESS you wire the subs in SERIES.... If you wire 2 4ohm subs in Series you sstay at 4 ohms..... ***** YES There we go the Brain has awakened******** So 4 4ohm subs as 2 pairs each 2 wired in series and hooked to a 4 channel amp bridged into 2 Channels...... Houston we have a 4ohm load......
> 
> Personally though Id try wiring them parallel and running the amp into and 2 ohm bridged load... as long as you have adequate power and the amp doesnt get hot you should be alright... and The subs will sound better.... But I no longer use anything that wont handle a 2ohm or lower load.... *


if you wire 2 4ohm subs in series you go to 8 ohms, not 4 ohms


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## LethalAudio (Feb 12, 2003)

unfortunately yes, yer right, its 8ohms not 4ohm. i was up till 4 in the morning calculating and recalculating every possible way to do it....i still get nothing...but i do feel a little better this morning, i think i finally accepted the fact that i gotta sell....but that still pisses me off....
tell me this though, what if i had an 8ohm and a 4ohm on each channel? anything? or still screwed?


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## sr20dem0n (Mar 19, 2003)

an 8 ohm and a 4 ohm in series would give 12 ohm and in parallel would give a 2.66 ohm load.


how does it sound if you hook them up in series to each channel so there's an 8 ohm load? They won't get as much power as if it was at 4 ohms, but it could be a temporary solution.


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## LethalAudio (Feb 12, 2003)

nah, i could do just the same thing by doin the regular + to + and - to -. 100x4....


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## sr20dem0n (Mar 19, 2003)

good point


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## LethalAudio (Feb 12, 2003)

ok, tell me this...I went down to my buddies house and me him and his brother went through every car audio directory you can think of...the only decent subwoofer i found was an MA Audio 12" um..300/600 watt, dual 4 ohm i think it was part of the MI series...ever hear anything bad about MA Audio? I dont know anyone that has them, ive heard of them, but thats about it, never anything good and never anything bad...and on top of that, they look like a pretty good sub, and they are only like 94 bucks(retail).


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## LethalAudio (Feb 12, 2003)

well, ive done some shoppin and i cant find anyone that carries MA. but what im really lookin for is either and 8ohm woofer, 2ohm woofer, or DVC woofer..all of them need to be around the 400-500watt MAX rating. any suggestions?


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## wolf (Jun 23, 2003)

yall nasty is right..... when you bridge an amp the load is doubled. instead of having a 100 x 2 @4ohm you have a 200 x 1 @2ohm. series the two coils should give you 8 ohms. bridged should give you 4 ohms.


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## LethalAudio (Feb 12, 2003)

I dont quite follow...ive drawn out every possible configuration based on what ive found on the net...alot of whay i used came from fosgate, they have everything about wiring posted on crutchfield( http://www.crutchfieldadvisor.com/S-ZhItxvr8IMR/learningcenter/car/subwoofers_wiring.html ). i hate to ask, but could you draw what you are talkin about? Its hard for me to get this stuff worked out in my head. and remember, this is a four channel amp were talkin about.


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## sr20dem0n (Mar 19, 2003)

wolf said:


> *yall nasty is right..... when you bridge an amp the load is doubled. instead of having a 100 x 2 @4ohm you have a 200 x 1 @2ohm. series the two coils should give you 8 ohms. bridged should give you 4 ohms. *


I have no idea how you came up with that, much less what you're talking about period, lol


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## LethalAudio (Feb 12, 2003)

im strugglin to figure it out too, i just dont see it


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## wolf (Jun 23, 2003)

i'm sorry i see what i did wrong. i'm just stupid. from what i can tell either way your getting the same power. so don't bridge the amp. here's how this works... so you have this four ch. amp, 100x4 or 200x2. if you bridge the amp ( forget ohms for a sec ) each sub is still only getting 100 watts because each sub splits the power. the total output of the amp remains the same.


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## LethalAudio (Feb 12, 2003)

exactly, it took me about 5 hours to figure that out, but in the process, i gained alot of knowledge that i neglected to learn over the years...which is, im sad to say, veeeery important.


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## wolf (Jun 23, 2003)

yeah i learned that way too. now i have been doing this for about ten years all together. btw if you know anyone that can repair amps let me know... i have a few that i let the smoke out.


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## LethalAudio (Feb 12, 2003)

i know of one place. the amp doctor. Im not sure where they are, but i can find out in a week or two. they repair everything and yu send them your amp and you write a price on the box that you wont go over and if is going to be more than you wrote, they call and ask you if its ok to go ahead. i cant remember anything but the name. i was going to send them one of my old amps but i wound up sending it back to fostgate just before i sold it. They repaired buddies amp, problem is, he's at the beach and i aint buggin him. ill find the number and address and get it to you soon as i can.


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## wolf (Jun 23, 2003)

that would be cool. the only place i know is avsl but they want to charge a left nut and i don't have one to spare. i sent them an alpine amp last year that was only 6 mos old that i bought new and paid $269 for they wanted to charge $330 to fix it + shipping. that will be the last thing i blow up for them.


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## LethalAudio (Feb 12, 2003)

aw hell no dude, thats a friggin rip off. these guys are cool, they fixed my buddies for like 130 bucks and in like 3 weeks i think. Im still lookin for the number, but try searchin the net for a place called "The Amp Doctor(s)" they are in the north western part of the us, thats all i can remember about location, unless they moved or something.


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## wolf (Jun 23, 2003)

cool ill try that thanks...


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## droppinbottom (Jun 30, 2003)

hay man i do this for a living if you wire two 4 ohm subs to one side of your 800a4 you are going to have either a 8ohm mono or a 2ohm mono load the 2ohm mono load is lower than the 800a4 will safely handle because the 2ohm mono load equals 1ohm stereo. i have run my 800a4 at a 1ohm stereo load but it gets hot a whole lot quicker and i would not do it if i didnt work for the store where my equipment came from.


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## LethalAudio (Feb 12, 2003)

well, ive had my 800a4 for about 5 years now and the whole thing about this new system is me keeping it and using it. I thought about runnin it lower than the recommended usage, but id rather not risk burning my amp up, the shop is in Cali (www.cbrstereo.com), and the warranty has run out on it.....Hmm, now that you mentioned it, I think the shop that installed my other 800a4, when I first got into systems, I think they are the reason it blew, it ran hot and it kept blowin fuses one day and I ended up sending it back to fosgate and letting them fix it. Just recently, one of the channels went out on it. Im pretty damn sure they wired the subs wrong. And they stole one of my buddies amps....damn bastards, we got them back for that though. I dont think they liked me cuz I didnt buy from them...f**kin imbred ******* hillbilly bastards...i cant stand them.
I talked to one of my friends friends and I may just have a buyer for my new system, if thats the case, I can buy my new 8ohm subs and have the system up and runnin in a few weeks. Thanks for that info though, I appreciate any info about what the 800a4 can do, its quite a versatile amp, especially if you can run it at 14.4Volts.


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## droppinbottom (Jun 30, 2003)

the 800a4 is a very good amp and versatile. my old 800a4 came with a birthcertificate that said close to 1200 watts max. each amp is different it could have more or less i picked through our inventory and picked the one with the most output. i am currently running a much smaller system with a 600a4 running the whole thing. keep in mind when you start looking for a new system if you change from RF to a different brand its ohm load capabilities may be different.


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## LethalAudio (Feb 12, 2003)

i seriously doubt ill change to anything else other than RF, they have exceeded my expectations thus far and ive only blown 1 sub out of the 12 ive owned through the years. I know people that didnt use RF and they had the same spec subs as the XLCs i had, they went through sub after sub(literally). I had the same subs i started with when I had my 8-12s in my bronco, the time difference was about 2-3 years, and my friend still has 2 of the XLCs i sold him. He just blew one of them, but hey, they cant last forever.
MY 800a4 is certified at 1008watts. Not the highest rated one, but still impressive by amp standards. Especially when you consider what they are advertised at, i think it was 100x4 in crutchfield. I doubt Ill ever switch to anything other than RF cuz I already know their equipment and what its capable of and if i were to switch, Id have to go and learn a whole nother brands specs.


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## droppinbottom (Jun 30, 2003)

their older equipment is the deal i dont like the new stuff all that well. i like the old school days when subs couldnt handle alot of power and were very efficient. and the amps were only rated at like 200 watts and would put out over 500watts. i guess all manufacturs are rating their equipment at max power now days.


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## LethalAudio (Feb 12, 2003)

That seems to be the case. RFs old stuff seems to be what everyone is after now, but like you said, its alot better. My friend is selling his whole system which inlcudes the 650 thats pushin his 8 XLCs. He wants 1500 for it all, but Id buy it just for the 650. Its one of Fosgates best amps to date, IMO. They just dont make em like that any more. And if Ive said it once, Ive said it a million times, its hard to beat RF. 95% of the people I know that are big time bass junkies have RF and they can stomp about everything with the same specs as thier systems and sometimes even the bigger ones. Everyone else I know that has that has systems that arent RF or competition standard systems, they've had so much trouble its hilarious, Ive never had any major problems. But all car audio equipment is different, even if it is the same make and model. I suppose it all depends on the TLC you give your system. Though, I dont know anyone with a Fosgate system that hasnt taken care of it. In case you havent noticed, I am without a doubt an official RF "Fanatic".


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## sr20dem0n (Mar 19, 2003)

well I've heard 2 RF subs and was NOT inpressed in the least by either of them. On one we hooked up temporarily in my box and I couldn't help but laugh at how weak it was. It was a 10", not sure of the model, but it was maybe 1/3 as loud as my single jl 10 w0 and it was distorted like a mofo. The other is my friend's setup in his crx, he just has 1 RF 12" and my 2 jl 10 w0's would wipe the floor with it (obviously 2 10's are going to be louder than 1 12, but even taking that into account it was a complete slaughter). With our cars sitting next to each other with the windows down, you could barely even hear his sub over mine even when sitting in his car! After those experiences I'm staying away from RF, their amps might be nice but their subs are lacking big time (atleast from what I've heard myself).


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## LethalAudio (Feb 12, 2003)

you VC musta been blown cuz RF is an excellent quality sub, what kind did you have?


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## sr20dem0n (Mar 19, 2003)

I didn't have any, it was a friend's sub that he was testing to see if he liked it before he bought it. Needless to say when my bottom of the line jl put it to shame he didn't buy it. The VC could have been blown, but my other friend's 12" RF still sucked, though not as badly


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## LethalAudio (Feb 12, 2003)

it had to be blown, aint no other explanation for it, but hey, you cant please all the people all the time.


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## droppinbottom (Jun 30, 2003)

the store i work for on the weekends sells rf. even though they are probably the best company to buy equipment from(waranty) i choose to run 3 jl 12w-6 in my 200sx. put on a meter a weighted i could get 148.6 out of it on a c weighted meter i could get about 151 out of it. the point is a friend of mine threw 3 rf 12power dvc in his acura and was getting 149.4 on the same a weighted meter. our rf rep swears that you can take any rf sub and put it in any box designed by any competor for their sub and it will be louder. its true from my experiences.


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## sr20dem0n (Mar 19, 2003)

there's a guy who took a single 15" edesigns sub and hit 153.6db

http://www.edesignaudio.com/ep/news/regalreview.htm


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## LethalAudio (Feb 12, 2003)

im glad somone else around here can appreciate RF. but as happy as i am with RF, ive always wanted to own some JL subs, i know they are good, but i dont wanna drop the cash for them. plus, i dont think they make a subs designed to the specs im lookin for.


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## droppinbottom (Jun 30, 2003)

demon was the person playing music or was he sending test tones with that single sub? we have local guys who are in the 170 spl range with only two subs. one they are using test tones and two they are not daily driver vehicles. my jl subs were in the trunk of my vehicle and the mic was on the pasenger side of the vehicle windshield one inch from the bottom of the glass.


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## sr20dem0n (Mar 19, 2003)

I belive he just went to the competition, played a single tone, hit 153db, then drove off playing music. The 153db was on a test tone but the system wasn't tuned for a single tone, it was a normal system that he just used for that competition. Actually I believe he said it wasn't even tuned at all, that he had just slapped it together right before that competition, but I'd have to read that review again to be sure.


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## wolf (Jun 23, 2003)

back a few years ago.... when they had those chrome amps. rf was the amp to have. now they seem.. well mass produced. i think their quality has suffered quite a bit, but the price has went down. i want to see if anyone has tried the new dei stuff since they aquired a/d/s. i think for the money rockford still makes a good product. i just prefer to do business with smaller companies like orion the past few years, or rockford a few years back. they seam to want to keep you as a customer. now that dei owns orion i can't get them to answer the damn phone.


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## LethalAudio (Feb 12, 2003)

Damn man, I didnt know Dei bought Orion, thats news to me. 
Ok guys, Ive been thinkin about this, I dont think Im going to be able to sell this stuff so I may have to settle for what I traded for. But I have a few concerns. Ok check this out.

The 800a4
- Rated at 240x4 at 14.4v
- Rated at 200x4 at 13.8v
Got that? Now, I can only get my system to run at 13.8v an no higher, unless the cap is wrong or something, but it too is a RF 1 Farad Digital Cap.

Ok, heres the specs on that 750s I traded for, it was bought to push the 15"s(as if you didnt already know)
- 4ohm Load Per Channel - 187.5x2 at 14.4v
- 2ohm Load Per Channel - 375x2 at 14.4v
- 4ohm Load Bridged(Mono) - 750x1 at 14.4v

BUT here are the (relevant)readouts on the Punch Verification Certificate from the 750s
Test Impedance = 2
Test B+ Voltage 13.917
Actual Total Power 837 (continuous RMS)
(All channels driven into full power at 2ohm)

If I run that amp with my car and cap its only gonna get 13.8v right? Right. So obviously the wattage is going to drop buy a little bit.
Ok, this is where I need you guys to pay attention, cuz I need to get a 2nd opinion to confirm my calculations.
If I keep these two 15"s and run them with this amp, would I be right in thinking that I can run it in the 2ohm config. and put two on one channel and save the other channel for when I get some money and buy two more subs. I could wire them all in Series-Parallel and get the 4ohm Bridged Mono setup.
Someone tell me if this is right, Im 99% sure it is, but I just woke up and Ive been thinkin about this pretty much all morning my mind is clouded.


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## droppinbottom (Jun 30, 2003)

i would never try running my system with just one chanel of an amp being used unless it was set up as mono L+R- 
what king of subs are they again ? DVC or SVC and at what ohm per voice coil?


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## LethalAudio (Feb 12, 2003)

Its RF HEs 4ohm SVC. As for using half the amp, for about 3 years, I used only two channels off my 4 channel Jensen when I had only one component system. What concerns you about the single channel setup? I never heard anybody havin any trouble not using every channel on their amp.


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## droppinbottom (Jun 30, 2003)

i have seen it done before just dont care to do it myself. did u bridge the a and b sides of the amp? 4 chanel amps can be run 2/4 chanels


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## LethalAudio (Feb 12, 2003)

Nope, its just straight up + to + and - to - on the front channels. Its the perfect wattage for the component system. 75watts RMS, 140 peak. I havent used the back channels since I had it bridged for my two XLCs in my first system. Ill tell ya whut...that Jensen amp has surprised the hell out of me, lasting this long, I only paid 100 for it, and I bought it used...go figure, lol.


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## droppinbottom (Jun 30, 2003)

what i am trying to say is that a 4 channel amp is basically 2 amps in one housing u can do that with a 4 channel amp . you dont get the amps full capabilities but it works. a 2 channel amp is a different story IMO i would not run just one channel. my system is being run off of a RF 600a4 with my highs on the A side of the amp at a 2 ohm stereo load and my single dvc sub(dual 4 ohm) being run off the B side of the amp at a 8 ohm mono load. thus i am running my 4 channel amp in 3 channel config.


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