How hard are RSIIIa to drive?

Ross6860

AK Subscriber
Subscriber
I would like to use my RSIIIa and RS5b as Main and Surround speakers in a HT setup. Are these speakers hard to drive, as in do they dip way down to 2 or 3 ohms at any frequencies?

I don't want to subject the speakers to any abuse and don't want to blow any tweeters either.

Can these speakers be driven at moderate levels by any of the new (read - junk) BPC HT receivers? Fuses won't protect them from distortion induced damage.

I have an Onkyo TX-NR646 as my current HT receiver.

I don't play very loud, but the explosions, cannon fire, etc. in movies may tax the system a bit.

I should probably just save up for a decent 5.1 amp/pre-amp setup and not worry about it.
 
Unless you are trying for "glass breaking, bounce stuff off shelves" type of sound, no, you can drive them w/ a respectable receiver.
If you have your spealers set to "small", any sound under 120 Hz wil go to the sub woofer anyway.
Bigger problem is going to be voice matching them to a center channel speaker.
You want your front three to be all from the same series so the sound will move across the front in a seamless manner.
I couldn't find anything that matched at all..
It makes a huge difference.
I always wanted to try and build one out of two Emits, and two polydomes, but haven't got that far.

My two cents Stu
 
They are 4 ohm speakers. The EMITs are demanding and wil dip to to that lower range. If you have pre-outs (the better AVRs have them) I'd look at two amps for the front and rears (maybe a little less for the rears) that have some real headroom. I wouldn't risk the weakest link in the chain.
 
The RSIIIa/b is rated 4-8ohm.
The 3.2 ohm woofers are wired in series making 6.4 resistance.
The mid measures 4.5 ohms and the EMIT should be 5.7ohms.
While playing them through your receiver feel for any unusual heat before turning the volume up to near realistic listening levels and continue to be wary of overdriving just to make sure nothing is amiss.
 
Maybe I'm just lucky, but I was driving my RSIIIA's with a Marantz 2245 for at least a year with only one incident. One evening, I was listening to some music at fairly high volume (3/4 volume knob rotation) when I was interrupted by a neighbor, who asked me to come outside to look at her lawn mower. While out in the yard a very bass heavy song came on and I could hear the woofers distorting badly, so I hurried back inside and turned it down to normal levels. No damage was done, but I have since returned the 2245 to pre amp duty, using a Crown XLS1500 as a power amp, just in case I get caught off guard again.
 
You can do it. I have RS-IIIa's in the front and Infinitesimal Four's in the back in my HT. I used to run them using simple Onkyo TX-8522 2-channel amp (rated only for 8 Ohm, 100 wpc) w/o any issues. Loud enough for practical purposes but nothing earth shattering.

Now I am using Yamaha HTR-5730 which has similar power specs as TX-8522, but is way better for HT since it is a proper 5.1 channel amp. Yamaha drives all 5 speakers (the 4 Infinity's above and a center channel). But again, I can not reach earth shattering volume levels.

In particular, the amp can not drive the RS-IIIa's at loud levels through sequences that use LFE (some low freq special effect thingy, handled by the main speakers (i.e. RS-IIIa) in my current setup). The LFE signal (Alderaan explodes) puts the amp in protection. Since I do not have powered sub (coming at some point), I have had to reduce the LFE signal by 5 dB to be able to have loud enough volume level in general while not putting the amp in protection during special scenes (Alderaan had to explode several times for finding the optimal attenuation). For all practical purposes the combo now works great.

Now, having said that, I used to have the RS-IIIa's in the living room as my main 2-channel speakers, and driving them with Onkyo TX-8522 was less than optimal. Onkyo A-9070 (clean 145 wpc at 4 Ohm) on the other hand was a great match for these speakers.

In short, basic HT receiver will do the job, but 150 wpc at 4 Ohm amp will really make the speakers shine. And/or get a powered sub.

PS: See the About segment in my profile for details of the HT setup.
 
Well I agree, it can be done if you're careful and don't over do it. The powered sub will definitely take some of the load off the Infinitys. I was just suggesting a scenario where you wouldn't have to "worry" so much, but no doubt if you take it easy you can get away with using a 5.1 AVR with 100 watts or so per channel. But if your kids or neighbor or someone decides to say "hey, those are some big speakers, lets see what this baby will do", you might have a mishap. I came home from work one evening early and could hear my stereo from a block up the street. My daughter would get home from school and crank it until she thought it was time for me to show up. She didn't blow anything up, but managed to destroy the surrounds in my speakers. It's hard to protect your gear from every possible "hazard", especially human ones.
 
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