Is it safe to run rsd 1200.1 at 1.34 ohm's

smokeyand thebandit · Post by **smokeyand thebandit** » Sat Oct 30, 2010 9:39 am

I have hooked up three 4 ohm 10 inch subs in parallel to my rsd amp. I am also using a 2 farad capacitor as a distribution block for two amps, is this a bad idea as well?

smokeyand thebandit · Post by **smokeyand thebandit** » Sat Oct 30, 2010 9:40 am

Post by **kg1961** » Sat Oct 30, 2010 10:19 am

NO

2ohm only on that amp

Post by **Bfowler** » Sat Oct 30, 2010 10:24 am

can't say i reccomend it. if you can build a fan cooling system...it MIGHT not die...

smokeyand thebandit · Sat Oct 30, 2010 10:49 am

GAY! it sounds way better with the third sub. Subs are 400 watts rms each amp is 1200. I don't know a way to keep it at 2 ohm's with three subs, but if I had four could I wire two speakers sets of two in series and then run the two sets of two in parallel?

12voltjunky · Post by **12voltjunky** » Sat Oct 30, 2010 12:39 pm

from what i understand, that 3rd sub is only adding around 1db to your subs output. You could run two subs and either a)save spave or b)build a an enclosure and give both subs their maximum airspace....just a thought.

Stryker · Post by **Stryker** » Sat Oct 30, 2010 7:17 pm

I think you'll be ok although the trade off is not worth it IMO. prolly a huge ass power draw off your electrical and the amp is working mighty hard for very little gain. just have the bass boost at "0" on the amp and have the gain at no more than a 1/3 up. I mean it's only a 250.00 unit so it's disposable. On the one hand mine don't really even get hot at all 2ohm's. on the other hand you should be ok.

smokeyand thebandit · Post by **smokeyand thebandit** » Sat Oct 30, 2010 7:50 pm

the electrical draw is more noticeable now with three subs and I am hopeful that upgrading the big three to 1/0 and the main power and ground to 1/0 will help with the clipping at high volume. I can see a high amp alt in the near future too.

Pillow · Post by **Pillow** » Sat Oct 30, 2010 9:20 pm

Technically no... But F it. They are cheap and disposable.

I would run it.

IMO it is an epic fail on Rodin PGs part that the rsd1200.1 is not rated for 1 Ohm.

Stryker · Post by **Stryker** » Sun Oct 31, 2010 2:41 am

Pillow wrote:

IMO it is an epic fail on Rodin PGs part that the rsd1200.1 is not rated for 1 Ohm.

very true

Post by **stipud** » Mon Nov 01, 2010 8:04 am

PG always made 2 ohm optimized monoblocks until recently. Forcing you to use 1 ohm just to extract the power of an amp is "cheap" in my mind. In fact the higher the optimized impedance, the better. You will get better damping and SQ from it. Compare an amp that makes 1000w at 4 ohms vs 1000w at 1 ohm, and the 4 ohm amp will more often than not be far better built, because it needs to be to handle the impedance. If extracting every last drop of power out of the amp is the intention, then 1 ohm optimized is the way to go. But that's not why we buy PG gear, is it?

The RSD amp will be able to handle the 1 ohm load, but it will run hotter, sound worse and draw more power for only a slight increase in bass output. Balance the pro and cons and decide for yourself.

runinriot · Post by **runinriot** » Mon Nov 01, 2010 8:26 am

i sold a friend of mines my other 1200 a couple years ago and ran it @1.33 on 3 TC sounds DB-500s and its still kickin. gets a little warm but not hot at all.im sure its the impedance rise that keeps it in from goin smoke. but if you feed it right and and be responsible with the gain i dont see why you couldnt run it at 1ohm but i dont think its worth the extra effort.

Stryker · Post by **Stryker** » Mon Nov 01, 2010 12:51 pm

stipud wrote:PG always made 2 ohm optimized monoblocks until recently. Forcing you to use 1 ohm just to extract the power of an amp is "cheap" in my mind. In fact the higher the optimized impedance, the better. You will get better damping and SQ from it. Compare an amp that makes 1000w at 4 ohms vs 1000w at 1 ohm, and the 4 ohm amp will more often than not be far better built, because it needs to be to handle the impedance. If extracting every last drop of power out of the amp is the intention, then 1 ohm optimized is the way to go. But that's not why we buy PG gear, is it?

The RSD amp will be able to handle the 1 ohm load, but it will run hotter, sound worse and draw more power for only a slight increase in bass output. Balance the pro and cons and decide for yourself.

Your right stipud, I'm glad you put it in that context for me. honestly at 2ohms my 1200's sound great

smokeyand thebandit · Post by **smokeyand thebandit** » Mon Nov 01, 2010 6:26 pm

So @1ohm I would have a whopping 2400 watts, @1.34 say 1800, but I only want to get 1200 for three 400 watt speakers. I added 400 watts to the equation with the third speaker so I should get 33% or 1/3 more sound out of my subs. I noticed a big difference but I like lots of bass. The truck sure bogs out now though as I expected because I haven't upgraded anything else yet. need suggestions for gear.

Post by **stipud** » Mon Nov 01, 2010 7:02 pm

smokeyand thebandit wrote:So @1ohm I would have a whopping 2400 watts, @1.34 say 1800, but I only want to get 1200 for three 400 watt speakers. I added 400 watts to the equation with the third speaker so I should get 33% or 1/3 more sound out of my subs. I noticed a big difference but I like lots of bass. The truck sure bogs out now though as I expected because I haven't upgraded anything else yet. need suggestions for gear.

Haha... it doesn't quite work like that. If the amp were 1 ohm optimized, yes. However, running below 2 ohms will not get you much more than a hundred or so extra watts. The powersupply is regulated and will only produce enough power for 1500 watts, give or take, even if you are running at 1 ohm.

smokeyand thebandit · Post by **smokeyand thebandit** » Mon Nov 01, 2010 7:26 pm

should have bought 2ohm subs and ran them in series.

smokeyand thebandit · Post by **smokeyand thebandit** » Mon Nov 01, 2010 7:37 pm

12voltjunky wrote:from what i understand, that 3rd sub is only adding around 1db to your subs output. You could run two subs and either a)save spave or b)build a an enclosure and give both subs their maximum airspace....just a thought.

I could try making a box that will pound two subs better than these factory loaded one's do.

Stryker · Post by **Stryker** » Mon Nov 01, 2010 8:18 pm

smokeyand thebandit wrote:should have bought 2ohm subs and ran them in series.

yes hindsight is 20/20, I do think with a really stout box built for 2 subs it will pound real good.

Kurt Wild · Post by **Kurt Wild** » Wed Nov 03, 2010 5:17 am

What subs are you using and what size/type enclosure? Especially if youre using a closed box you should be fine. A speakers impedance depends on the box and frequency, its not a constant 4 ohm. The nominal impedance is usually the speakers minimum impedance.

smokeyand thebandit · Post by **smokeyand thebandit** » Wed Nov 03, 2010 5:50 pm

I'm running 3 10" kicker cvt factory loaded sub boxes.

Kurt Wild · Post by **Kurt Wild** » Thu Nov 04, 2010 11:47 pm

The manufacturer sure has stuffed those subs into compact boxes. I mean their minimum recommended sealed box volume is 22,7L whereas those factory boxes are about half that!

If you put those subs into recommended volume boxes you will be lookin at massive gains in both sensitivity (+4dB) and SQ. Their impedance will rise many ohms too, and you wont have to worry about your amp anymore.
They might be over their head power handling wise though, so use all three to get enough bass.

I bet the way they are now they are putting out tiiight lower bass but the upper bass is booming like hell. I had a 13" Focal polyglass sub in an undersized sealed box and I hated the booming and hanging upper bass. It was impossible to integrate the sub output with the midbass too.

00goobs · Post by **00goobs** » Sun Nov 07, 2010 6:59 am

Against better judgement, I have run the RSD1200.1 on 2 15" Type Rs at @1ohm or a bit less. It didn't ever get warm at more than 30 minutes of moderate listening and a few songs of heavy bass. It was hotter sitting in the car all day than it actually running seemingly. It did go into protection a couple of times on hard hitting bass drums, pretty much one song (Flowbots' 08 Combat).

Now I have one RSD per sub, so they're very happy @ 2ohms each....

smokeyand thebandit · Post by **smokeyand thebandit** » Sun Nov 07, 2010 8:47 am

I don't have enough room without sacrificing the whole back seat area to make a bigger box and keep three subs. I have the third sub in the front of the seats and the two you see in the back while the amps hang out under the folding rear seat. when I tried to put the third sub in the back it was about 1.5 inches to long.

so I could try a box for two with more volume. This truck is half the problem because there is not much room in it for this kind of stuff while keeping it functional. after a good crank session I noticed that it was the four channel amp was the one getting hot could be the way I have it hooked up to the capacitor with the sub amp? I am ditching the cap when I rewire with 1/0. Thanx for all the info guys.

smokeyand thebandit · Post by **smokeyand thebandit** » Sun Nov 07, 2010 9:09 am

I have also noticed when the stereo goes into protection mode I am losing both amplifiers together for a split second. On and off til I turn it down. I also notice if my windows are up and i try doing them up again it kind of surges and I will lose the sound then too. I think this is happening in the head unit because it is happening with the volume really low. so I'm wondering if I should run a second battery just for the stereo and the stock battery just for starting, the only point where the two batteries will come into contact with each other is at the alternator charge wire where it will be split to both batteries.

oldschoolfan · Post by **oldschoolfan** » Sun Nov 07, 2010 1:40 pm

If you are in love with the idea of using all three of those subs and you are only 1.5 inches too short on space, you should just copy the dimensions of the factory kicker enclosures and build one enclosure to fit all three. As in just make one long box. The inch and a half you are missing in your truck can be made up by eliminating the extra material in having three boxes, you know where all three would be butting up end to end. You could even keep them divided with their own air space if you wanted to. It can be done and keep that same volume kicker designed them to have.

It sounds like you really need to update your electrical supply. Big three is essential. A second battery would be sweet too especially if your truck already has the space for it under the hood. Don't be afraid of them being connected to each other. It is best however if the two batteries are identical in brand, age, series, and cca.