Bi-amp: SC05 + external amp

jcran17

I have Rti10 mains and a Csi5 center and am running an SC-05 receiver (130w/ch). My question is three-fold.
1.) If I get an external multi-channel amp, can I bi-amp using the 130w of the SC-05 to run the lows and use the external amp to run the highs (SC-05 manual suggests pre-amps and internal amp can be used simultaneously) and it looks as though passive crossovers are built into the speakers.
2.) The Rti10's are rated 300w/ch rms and the csi5 200w/ch rms. Am I to understand that they are considering each input terminal as a channel (i.e. 600w and 400w per speaker)?
3.) If I shoot for something in the neighborhood of 100w/ch in an external 3 channel amp, will it likely make a big difference?

jcran17

jcran17 wrote: »

3.) If I shoot for something in the neighborhood of 100w/ch in an external 3 channel amp, will it likely make a big difference?

Actually found a deal on a Carver av-405 that fits the bill nicely if any of this makes sense. It is 100w x2 (mains), 110w x1 (center), and 50x2 (surround, which I wouldn't use).

Sherardp

No need to biamp/bi-wire. Find a multichannel amp that has about 200wpc and your good.

http://app.audiogon.com/listings/sunfire-cinema-grand-5-channel-amplifier

EndersShadow

jcran17 wrote: »

Actually found a deal on a Carver av-405 that fits the bill nicely if any of this makes sense. It is 100w x2 (mains), 110w x1 (center), and 50x2 (surround, which I wouldn't use).

The Carver would work OK, but considering the Pio Elite models WPC tends to be pretty accurate you might not able to tell a big difference between them. The one thing the Carver has going for it is something called "power steering" where it will divert power from one channel to another for short periods of time if it needs it. So for instance my Carver AV705x amp is rated 125 WPC X 5 but it can send up to 293 watts to any one channel at a time. I am not sure how that translates into the 405 though so honestly I would pass.

Personally I would let the SC drive the speakers for now. I think you will find the you will make your ears bleed before you truly run out of gas on that SC. If you still think you need an external amp, you need to find one with something like 200 WPC @ 8 ohm and I would look used. Anything less than that will probably not make that much of a difference for you IMHO.

Also if you go the amp route I would look for just a 3 channel amp or a 2 channel and then a mono amp (all with the same WPC and manufacture if possible).

P.S. Act like you never heard the word bi-amp and forget about trying it. Save yourself lots of headache and problems

jcran17

EndersShadow wrote: »

Personally I would let the SC drive the speakers for now. I think you will find the you will make your ears bleed before you truly run out of gas on that SC. If you still think you need an external amp, you need to find one with something like 200 WPC @ 8 ohm and I would look used. Anything less than that will probably not make that much of a difference for you IMHO.

Thanks Enders. What I was hoping to do was actually use both the 130w/ch from the SC and the 100w/ch from the 405, each connected to different posts on the 3 primary speakers. I imagine it will take some work to get the gains right, but thought it might be a cheaper way to get in the 200+ w/channel range instead of, as Sherardp wisely suggested, getting a beefier amp.

EndersShadow wrote: »

P.S. Act like you never heard the word bi-amp and forget about trying it. Save yourself lots of headache and problems

This may end up being the best advice I receive...but it sure makes you curious doesn't it?

EndersShadow

jcran17 wrote: »

Thanks Enders. What I was hoping to do was actually use both the 130w/ch from the SC and the 100w/ch from the 405, each connected to different posts on the 3 primary speakers. I imagine it will take some work to get the gains right, but thought it might be a cheaper way to get in the 200+ w/channel range instead of, as Sherardp wisely suggested, getting a beefier amp.

What your thinking shouldnt work as normally most recievers turn off the amp channels when the pre-outs are in use . And even if they dont its still not recommended at all.

Curiosity will probably kill the cat, reciever and amp in this case.........

jcran17

EndersShadow wrote: »

If you still think you need an external amp, you need to find one with something like 200 WPC @ 8 ohm and I would look used.

Seems you had the same suggestion as Sherardp; Sorry I missed it first time around.

EndersShadow wrote: »

What your thinking shouldnt work as normally most recievers turn off the amp channels when the pre-outs are in use . And even if they dont its still not recommended at all.

The manual suggests on pg64 ("SP A" below) that it will allow both internal amp and preouts to function at the same time. Are you suggesting that this will somehow negatively affect the receiver?

"Press repeatedly to choose a speaker system option:
? SP A ? Sound is output from speaker system A and
the same signal is output from the pre-out terminals.
? SP B ? Sound is output from the two speakers
connected to speaker system B. Multichannel
sources will not be heard. The same signal is output
from the surround back channel pre-out terminals.
? SP AB ? Sound is output from speaker system A (up
to 5 channels, depending on the source), the two
speakers in speaker system B, and the subwoofer.
The sound from speaker system B will be the same as
the sound from speaker system A (multichannel
sources will be downmixed to 2 channels).
? SP (off) ? No sound is output from the speakers. The
same sound is output from the pre-out terminals
(including from your subwoofer, if connected) as
when selecting speaker system A (above)."

EndersShadow

jcran17 wrote: »

Seems you had the same suggestion as Sherardp; Sorry I missed it first time around.



The manual suggests on pg64 ("SP A" below) that it will allow both internal amp and preouts to function at the same time. Are you suggesting that this will somehow negatively affect the receiver?

It might, but I have no actual experience with the Pioneer Elite's so I will defer to MANTIS who installs them. Personally I have tried to "ghetto" bi-amp just about everyway under the sun and found that it doesnt make enough of a difference unless you have a really ineffecient speaker which you dont or listen to it till your ears bleed and your heart stops.

If you want to know what "ghetto" bi-amping is do a search for threads started by me and there are a couple that might help. Or just search bi-amp on the forum, there are threads aplenty on this subject .

To truly bi-amp this is what you actually need to do:

1. Pass the full range signal to a Equalizer that allows you to split the signal for each channel and set crossovers for the high's and lows independent of each other
2. Run one set of RCA interconnects to one amp for the highs for the Right and Left channels
3. Run the second set of RCA interconnects to a different amp for the lows for the Right and Left channels (conversely you could run one speaker off each amp)
4. Physically remove the internal crossovers on your speaker and directly connect the highs to Amp A and the lows to Amp B.


As you can see its a PITA to do and there is only ONE member I am aware of that has actually done "True" bi-amping (TNRabbit).

I would just run them off your SC and if you really think you need an external amp, look for a decent one but I think your better off not for now.

mantis

I read over this thread and at no point did I find a reason why you wanna bi amp other then curiosity.
I have a few questions:
1) What size is your room?
2) What purpose are the RTi10's being used for? From your sig I'm assuming theater and maybe music?
3) How you liking that 404 sub you got?
4) What benefits are you looking for with this idea of bi amping your main speakers?

After you answer my questions I can steer you into a proper upgrade. I'll have more depending on your answers.
I can speak from experience with your entire system as I have Installed it many times with the SC-05 , SC-07 , VSX models of all kinds from those years.
Your SC-05 should / will power the RTi10's perfectly. No need for an external amp. I do however see other things that could greatly improve your system much more then bi amping. Actually freeing up the SC-05 some with running the RTi10's in small and using a way better sub will yield much better results for both music and movies.

Talk to me

jcran17

Thanks Mantis.
The genesis for me wanting to add an amp was the impact I noticed when I appropriately powered (to RMS specs) speakers in my car, coupled with some comments on this forum that folks had similar observations powering up the Rti10, and lastly that I didn't hear much of an "upgrade" when I swapped my Csi3 with a Csi5 (I was thinking, perhaps wrongly, it was under powered). As for your questions:

1.) My room is a standard living room, 16 x 18 with wood floors with one 6ft opening into the room (opens to a similarly sized dining room). TV/center and mains are in one corner facing into the room. Opening is behind the left main. Optimal listening is corner of sectional couch in opposite corner of room. Sub is in the back corner behind the couch in corner opposite the mains. Center is mounted above the TV pointed down towards the listening area.
2.) Yes, HT and Music. Probably 70/30%
3.) I think the sub sounds OK with music but it could be a bit deeper when it comes to HT. Typically I think it sounds disconnected and it is more punchy than deep/rich.
4.) Looking for a more crisp sound to HT dialogue and an overall fuller sound with both music and HT. To my untrained ears, it sounds as though the midbass range is where I am lacking, but perhaps it is actually the low end.

I used the supplied microphone and MCACC to calibrate the SC. Mains and center are set to small; I was actually surprised at how low the MCACC wanted the gain to be turned down on the sub. HT is run through PS3 using the "Pure Direct" setting. Phase control is on and sub x-over is set at 80hz. 7th channel is used for zone 2 running a pair of Rt35i bookshelves in the dinning room. By all means, I would much rather not buy an amp and truly appreciate any insight you may have into how best to optimize my system.

mantis

I suggest adding 2 subs to your system , sell the polk sub and look into 2 higher quality models. You should try to get one sub up front . The rear sub's phase control should be set at 180. I don't like a rear sub only , it sounds as you described , disconnected when set up improperly.

You will find much better gains running 2 subs then buying amps and trying to get more out of the 10's. You will actually be surprised how much better your system will sound.

tonyb

I'll agree that the sub is the weak link, but also it appears you may have some setup issues going on. Go back into your receivers menu and see what levels your speakers and sub are set at. Adjust up if they are too low or to your likeing. Also, if you have the receiver doing the crossover to the sub, make sure your not using the crossover on the sub itself by turning it up to it's highest value.
Don't just use the auto calibration and forget about it, you need to tweek the settings yourself to get it to sound the way you like. As an experiment, disconnect the sub altogether, set the fronts to large and subwoofer to "no..or none", and see how you like the sound. That 404 sub I have a feeling isn't even keeping up with the front speakers or your room is too big and it can't pressurize it. If thats the case, best to leave it off and sell it for a more capable one.

jcran17

Thank you both for your suggestions. Clearly a sub upgrade +/- 2 subs sound like a necessary next step. I will certainly do some further researching, but do either of you have a sub suggestion? Mantis, I understand you have set-up a multitude of similar systems; are there a couple options off the top of your head that has worked nicely in the past?

Tonyb, in the mean time, I will play around with the small vs. large settings +/- sub and see if I can get things to sound a little better to my ear. I am using the receiver crossover (set at 80) and made sure to have the sub set at the highest value. Maybe I will try a higher crossover point to see if that helps as well.

cascius

I see you have similar issues to the ones I've been facing. I have the monitor line (M70s,M40s, CS2, PSW505) and i've been feeling the M70s haven't produced a nice midbass punch.

I just ebayed a new amp (Carver 705x) and will let you know what if it helps. I also think that I need to do quite a bit of tweaking of the MCACC, but I'll wait for the new amp before doing so.

Btw, how do you like that TV? I have the exact same model in 52" and it still preforms very well.

EndersShadow

That carver is nice. I have one and used it on monitor 60s CS2 and infinity primus 162s. Sounded great! Now it's driving my LSi 15s and LSiC quite well

jcran17

mantis wrote: »

sell the polk sub and look into 2 higher quality models.

tonyb wrote: »

That 404 sub I have a feeling isn't even keeping up with the front speakers or your room is too big and it can't pressurize it. If thats the case, best to leave it off and sell it for a more capable one.

Quick search revealed that SVS subs get a lot of attention; they aren't inexpensive, however. Might have to start trolling craigslist.

cascius wrote: »

Btw, how do you like that TV? I have the exact same model in 52" and it still preforms very well.

It is a number of years old now, but I am still very happy with it. Not even itching to upgrade at present.