New to the forum and curious to see thoughts on external amps

Welcome to CP!

There are mixed feelings here about the Emotiva name and their products. I have no personal experience though.

About your bi-amping... thats a strange way to do it. Not sure if it will work efficiently. Let some other chime in. I would almost recommend you use the XPA-2 on your mains with something in place of the stock jumpers (Horrible). I think that would give you what you want with room yet. The XPA-3 would be great for rears and a center if it were my choice.

I certainly don't agree with amping 1 pair of speakers and running the other off your AVR. I don't know enough about Onkyo to make that statement though.

jhkcam wrote: »

Somewhere I heard that an ideal setup for these speakers would be around 200-250 for the woofers and 150 to 175 for the highs.... the Onkyo is rated at 135 per channel so I figured if I amped the woofers (lows) then the Onkyo may power the highs pretty well. I could be off, again, just my initial number crunching here

If it's crossed @ 80hz maybe... I have the RTi A9's myself, those woofers aren't sweating much with 200 wpc while in full range. I run a Carver TFM-42 on mine. 375 wpc RMS and headroom to 750 watts... That makes them sweat. When bass is turned up, it starves for power. So the point is that power should be relative to your needs. Especially if your running them in full range turned up.

I run an XPA-5 and love it, but I have an LSi setup. I've heard many people say that the brightness of the Rti line and the brightness of the Emo are not a good match. No personal experience with an RTi/Emo setup though.

mdaudioguy wrote: »

My other suggestion? Forget bi-amping. Connect a single channel of any decent amp to each speaker, and while you're at it, go ahead and replace the stock jumper with some good quality speaker wire - DIY jumpers on the cheap. Given the gear you're working with, anything else is only going to be an infinitesimal improvement.

I agree. If you drop a grand on an amp, let it power the speakers by itself.

Welcome to Club Polk. Get a 5 channel XPA or other 200wpc amp, forget about biamping & be done with this particular upgrade. You can also check out Outlaw Audio for reasonably priced amps.

Or if you're willing to shop used on Audiogon, you can check out Sunfire, Rotel, B&K, Adcom, Nad, etc.

Biamping doesn't allow you to add watts. It is designed to allow you to run an active crossover between your avr and external amplifiers. That way you can control which frequencies go to which half of the speaker. It also keeps you from sending amplified highs in to the woofers and amplified lows in to the tweeter section.

Welcome to Club Polk jhkcam! :biggrin:

Since Emotiva generates a lot of animosity here I will not waste much time commenting except to point out that ideally a good demo is the best way to get the sound you like and unfortunately you can not really do that with Emo.

First, I wouldn't waste any time with bi-amping. As pointed out, the main goal of bi-amping is to isolate the high and mid more than anything else. When you bi-amp for power purpose, you need matching amps for best results.

In HT, you want to focus on your front stage and keep everything in balance (matching speakers, matching amps) so, when all considered a 3 channel external amp would be ideal to power your fronts and center equally. As far as your rear you can power them with your Onkyo without any issues as first the unused power from the front stage will be available for your rears and second even if that wasn't the case you have to realize the rear do not require as much power as the front stage in an HT set-up. Do not focus so much on watts but ratter on the SQ. BTW; always keep in mind that in order to make a real difference you must double the power. However, having an external amp for your front stage gives a break to your Onkyo (Onkyo are usually hotter than most receivers), provides for cleaner power all around and more likely would allow for better SQ.

Hi Michael1947,
Welcome to the CP Forum. Using two or more amplifiers to provide power for a single speaker system has been discussed quite a bit here and elsewhere, but let me see if I can give an opinion. There is "Bi-wire" with a capital "B" where there is no internal crossover used inside the speaker and all of the frequency shaping is done externally between the preamp stage and the amplification stages. There are many who feel that this is the only true way to bi-amplify and anything else is a waste of effort. Then there is "bi-wire" with a lower case "b" where the speaker's internal crossover is maintained and two individual amplifiers power the two "halves" of the speaker.
In Bi-amping a speaker the owner has to find a suitable external electronic crossover that provided sufficient adjustment capability to re-establish the proper blending of what the speaker's designer originally had in mind. At one time there were lots of companies that made these kinds of products, in fact the annual Audio Equipment Directory had a category just for them. Companies such as Audio Research made two, both vacuum tube based. But no longer, I can only think of Marchand off of the top of my head. The idea was that if you could do the frequency shaping before the amplification the communication path between amp and speaker tweeter or driver would be more perfect. Instead of large coils and bulky capacitors smaller line level, active circuitry could be used with less change to the integrity of the sound signal.
But, does this necessarily mean that "bi-amping" is to be not considered, not necessarily. One possible improvement could be the use of different connecting wires between the different amplifiers and the different sections of the speakers. One theory has it that when dealing with frequencies below around 600Hz it is the total series resistance of the speaker wire that is most important. With frequencies above 600Hz it is the series inductance that might make the sonic difference. If you are bi-amping you are free to experiment with connecting wire designs to maximize the sound performance, a thicker less resistant wire for the amp-to-woofer/mid range part of the speaker. And a smaller gauge solid core wire for the amp-to-tweeter part of the speaker.
Also some are of the opinion that different amplifiers have different sonic characteristics that lend them to different aspects of sound quality. A classic example is the excellent sounding Adcom GFA-535, the lower powered version of the GFA-555. Most feel that the 535 produces wonderful high frequency transient detail and lack of "hardness" or brittle quality. The 555, on the other hand, represents the kind of woofer control and dynamic range that can bring a speaker alive. Use a specific amplifier for its sound character, maybe solid state and vacuum tube blending? But, keep in mind both amplifiers need to have the same input sensitivity or one of them has to has some way of adjusting its output level to get everything balanced.

If you have two amplifiers available, try using them both and experiment with different speaker wires to see how you can change the sound character. As a test try some 300 Ohm twin lead solid core antenna wire on the treble amplifier and a thicker wire for the lower range. I hope this has been helpful.
Regards, Ken

I am not a fan of Emotiva personally but I am especially not a fan of emo and the RTi series combined. That has the making of a harsh sounding system to me. There is nothing wrong with Emotiva other than the fact that they can get kinda brittle when you start really using the volume. For most people this isn't an issue but I like a more balenced and mellow sound. Even for HT.

The RTi series is a bit bright to begin with so I would shoot for something warmer like B&K or Rotel before Emotiva.

^ This.

I love how my RTi A9's sound with my Carver.

I would buy the best two-channel amp you can afford. Your Onk has plenty of power for a center and 2 (or 4) surrounds. Put the money where it is most needed. That way you have a great stereo system and great HT.

Willow wrote: »

I would say that a 3ch is a min. requirement. That way the whole front stage has the same amount of power where it needs to be.

I agree with the above, you want your front soundstage to match power wise. HOWEVER, I also have my LSi 15's what I call "ghetto bi-amped". The Integra I have (like the Onkyo's) allows you to set the AVR to bi-amp in the menu and then sends the full signal for the high's and lows out via the fronts and rear surrounds.

What I did is to use that setting in the AVR and then connect those 5 pre-outs (2 per L/R + 1 for center) to my Carver AV-705x amp. I call it "ghetto bi-amping" since there is no EQ between the AVR and the amp so each set of interconnects are passing the full signal to my amp. According to a couple folks on the Carver forum, my amp is like 5 monoblocks in one chassis, they just all draw from the same power supply however. So while its not true bi-amping as the L/R highs and lows are on the same amp, the power draw doesnt overwhelm the amp by any means.

I found this makes things a little bit clearer at low levels, and gives me more punch. I have heard from others that have done similar that the differences continue as you crank it, but personally I havent experienced that since I live in an apartment and cant go hardcore on the volume knob. Plus I figure my 8 ohm surrounds are more than easy enough for the AVR to handle.

I dont think every 5 channel should be used like I am using mine however.

Congrats, I drove Rti10s with my Parasound 2250 before I switched to Lsi25s. I also had a Csi5 being driven by my Onk, which never seemed underpowered. The 2250 runs fairly cool (can't say that for Onkyos) and gave detail to my Rti10s that the Onk could not match. My wife and I heard flaws in CDs that we had never heard before. Listening to Tori Amos, I could hear each strike of the keys on her piano. Report back and let us know how you like it!