Help with ohms

cnoat

Hello all
If I biamp my rti 12's does it make the highs and lows 4 ohms.I have a chance at a really good deal on an adcom 5400.I was going to use the amp for the lows and my avr for the tweet.Any feedback would be greatly appreciative.

disneyjoe7

If your question if biamp'd does the resistance stay the same yes. Splitting them up doesn't changed the resistance of the speaker. Now I don't think rti12's are a 4 ohm speaker but a 8 ohm speaker.

cnoat

Thanks for your reply.They are 8 ohms.The 5400 is rated at 200 a channel running 4 and 125 running 8.So I guess I would hurt them running in a 4 ohm load?

cnoat

DisneyJoe
How do you like your halo?

disneyjoe7

LOVE IT


I hope you got the point.

cnoat

I figured.Been looking at them for a while.
Thanks for your help

comfortablycurt

cnoat wrote: »

Hello all
If I biamp my rti 12's does it make the highs and lows 4 ohms.I have a chance at a really good deal on an adcom 5400.I was going to use the amp for the lows and my avr for the tweet.Any feedback would be greatly appreciative.

How exactly are you planning on connecting that all?

Generally, when you connect an amp to the AVR's preamp output, it bypasses the AVR's internal amp, so you likely wouldn't even be able to bi-amp them with this method. Anyone correct me if I'm wrong on that though, as I've never tried it.


Aside from that, using two different amps for bi-amping can be complicated. Different amps have different gains, and won't necessarily match up well.


You'd be MUCH, MUCH better off simply using the Adcom to power your RTi12's, rather than trying to bi-amp them using both the Adcom and the AVR. A good external amp is going to smoke any AVR, on any day of the week.

Thanks for your reply.They are 8 ohms.The 5400 is rated at 200 a channel running 4 and 125 running 8.So I guess I would hurt them running in a 4 ohm load?

I think you're still kind of confused here. The RTi12's are an 8 ohm speaker, so they'll be presenting the amp with an 8 ohm load. You won't be drawing 200 watts from the amp, but only 125. But, the Adcoms 125 watts at 8 ohms isn't going to be any different from a volume/headroom perspective, than 200 watts at 4 ohms. Due to the different resistance, either way would be the same actual power level. It's not as if you can choose to run either the amp or the speakers "at 4 ohms". The impedance of a speaker is constantly fluctuating, as the demands of the reproduced material change. An 8 ohm speaker, isn't presenting an 8 ohm load all the time. The 8 ohm rating is simply a nominal(or average) impedance rating. For instance, all of the LSi series speakers are rated at 4 ohms nominal. However, sometimes they can dip down to below 2 ohms, depending on the material they're trying to reproduce.

As mentioned above, when bi-wiring them, each section of the speaker will still be 8 ohms.

cnoat

Do you think 125 a channel is enough to push them.I am running 110 right now and my rti8's sound much better.

comfortablycurt

cnoat wrote: »

Do you think 125 a channel is enough to push them.I am running 110 right now and my rti8's sound much better.

What AVR are you using?



There is a WORLD of difference between an AVR's power amp section, and a good dedicated, high current external power amp. The 125 watts from that Adcom is going to completely blow away the 110 watts from your AVR. Ask anyone on this forum that's went from an AVR to an external amp...and they'll tell how big of a difference there is.

I've run my Monitor 7A's, SDA 2A's, and the RTi8's that I used to have off of my old Onkyo 606 AVR. I thought it sounded pretty good through the AVR, but when I got my 2 channel separates...I was blown away. The 606's advertised power output is 90 wpc. The power output of my Adcom 545 is 100 wpc. A 10 watt increase isn't going to produce any kind of an audible increase in volume...however, AVR watts and real amp watts are entirely different animals.

Once I connected my speakers to the Adcom, I found out just how big of a difference there is between the two...;

My overall maximum volume level went WAAAY up. There's much more dynamic headroom with the Adcom, and everything has much more of a sense of musicality. In other words, you'll be just fine driving the RTi12's with 125 watts of Adcom power.;)



Like I said above...I would strongly suggest just using the Adcom.


Also...can you even confirm that it would be possible to bi-amp them in the method you described? Like I said above, generally when an amp is connected to an AVR's preamp output, the receivers outputs for those channels are muted, in order to reduce the load on the amp, and free up some breathing room for the other speakers.

cnoat

No I really don't know if I can run my avr and an external the way I was planning.I was just assuming.Thanks for all your input.I can see you know way more than me.My 12's sound horrible.Compared to my 8's.


Onkyo 898
Mains rti 12
Center csi5
surrounds rti8
Back Surrounds rti6

disneyjoe7

Like Curt is saying above, try to run the 12's with the Adcom amp directly to see if they sound better. I think they would over an AVR, since the 12's are a bit much over what an AVR can handle.

cnh

cnoat wrote: »

No I really don't know if I can run my avr and an external the way I was planning.I was just assuming.Thanks for all your input.I can see you know way more than me.My 12's sound horrible.Compared to my 8's.


Onkyo 898
Mains rti 12
Center csi5
surrounds rti8
Back Surrounds rti6

With enough power those 12s should be TROUNCING your 8s!

cnh

tonyb

Plus if your running all 5 channels at the same time,I'll bet your pushing less than 50 watts/per into those 12's from your receiver. Feed them some juice.

cnoat

Thanks for all your input guys.I am going to pick up the adcom now.100 bucks awesome!!!!

comfortablycurt

cnoat wrote: »

Thanks for all your input guys.I am going to pick up the adcom now.100 bucks awesome!!!!

For $100, that's a no brainer!! Nice find!!

Now get that puppy hooked up!!:D