Best amp for Polk Rti series and Yam 2500

[Stepheng]

I have read this forum for sometime and need advice. Which amplifier would best "match" a Yamaha RXV-2500 and Polk Rti 12's, Csi5, and Fi5's: Adcom 7807, Sunfire Cinema Grand, Emotiva, etc...? I'm considering passive biampping Rti12's, thus the need for a seven channel amp for 5.1 system. I am very happy with the RTi's and Yamaha, but I need an amp. to bring out the best in these speakers. thanks for the help.

 

[mtrycrafts]

I have read this forum for sometime and need advice. Which amplifier would best "match" a Yamaha RXV-2500 and Polk Rti 12's, Csi5, and Fi5's: Adcom 7807, Sunfire Cinema Grand, Emotiva, etc...? I'm considering passive biampping Rti12's, thus the need for a seven channel amp for 5.1 system. I am very happy with the RTi's and Yamaha, but I need an amp. to bring out the best in these speakers. thanks for the help.

Why do you think you need to biamp the sppeakers, especially in a passive mode? Curious.

 

[Stepheng]

The mains have four binding posts, so its possible; also having dedicated channels powering the highs and lows will help, even in a passive setup. To do active biampping is too complicated in disabling internal x-over, plus I'm not opening and digging around in my new speakers. Also, I thought biampping the mains via a seven channel amp. would be an easier load on an amp. rather than having one channel drive 4 ohms. Although, I could be wrong, I'm still learning about all of this. (the Rti 12's are 4 ohms with straps connected and 8 ohms unstrapped, according to previous posts on this forum.) If the 4 ohms are not that big of a deal with current draw from the wall, then I very well may go with a good 5 channel amp. Any thoughts?

 

[Buckeyefan 1]

Do you have a 5.1 or 7.1 setup now? Any of those amps will do nicely. I'd even consider adding this between the preouts and new amp for tremendous control.
http://www.hometheateraudiocontrol.com/product.asp?Product_Id=19888&d_Id=5648&l1=5648&l2=

 

[mtrycrafts]

The mains have four binding posts, so its possible;

Oh, OK.



also having dedicated channels powering the highs and lows will help, even in a passive setup.

Or, it will not help at all in a passive mode.

Also, I thought biampping the mains via a seven channel amp. would be an easier load on an amp.rather than having one channel drive 4 ohms.

Not at all. Actually it will be more difficult as now you will be driving a much lower impedance drivers, so it is harder on the amps, especially when you start out with a 4 ohm speaker and will end up with around 2 ohms on each channel.


If the 4 ohms are not that big of a deal with current draw from the wall, then I very well may go with a good 5 channel amp. Any thoughts?

Which wall are you talking about? Dependiong on speaker sensitivity and your loudness level when playing them, you may or may not be ok.

 

[Buckeyefan 1]

?

The mains have four binding posts, so its possible;

Oh, OK.
also having dedicated channels powering the highs and lows will help, even in a passive setup.
Or, it will not help at all in a passive mode.
Also, I thought biampping the mains via a seven channel amp. would be an easier load on an amp.rather than having one channel drive 4 ohms.
Not at all. Actually it will be more difficult as now you will be driving a much lower impedance drivers, so it is harder on the amps, especially when you start out with a 4 ohm speaker and will end up with around 2 ohms on each channel.
If the 4 ohms are not that big of a deal with current draw from the wall, then I very well may go with a good 5 channel amp. Any thoughts?
Which wall are you talking about? Dependiong on speaker sensitivity and your loudness level when playing them, you may or may not be ok.

What????? Does that mean anything???

 

[mulester7]

The mains have four binding posts, so its possible;

Oh, OK.



also having dedicated channels powering the highs and lows will help, even in a passive setup.

Or, it will not help at all in a passive mode.

Also, I thought biampping the mains via a seven channel amp. would be an easier load on an amp.rather than having one channel drive 4 ohms.

Not at all. Actually it will be more difficult as now you will be driving a much lower impedance drivers, so it is harder on the amps, especially when you start out with a 4 ohm speaker and will end up with around 2 ohms on each channel.


If the 4 ohms are not that big of a deal with current draw from the wall, then I very well may go with a good 5 channel amp. Any thoughts?

Which wall are you talking about? Dependiong on speaker sensitivity and your loudness level when playing them, you may or may not be ok.

.....Mtrycrafts, your thinking is, "if I never give answers, the audiophite will be encouraged to dig on and learn"....that's it, isn't it?....not trying to rile you up, and I appreciate much, your demeanor in responding to me thus far.....

 

[AVRat]

Actually, passively bi-amping speakers is a very tricky proposition to accomplish effectively. The Yammy 2500 will easily drive the surrounds alone. Your money is best spent on a quality 2-channel amp to drive the Rti-12s.

 

[mulester7]

.....and may I add, Mtrycrafts, you say some two and three word combinations that attain being profound, imo.....

....what I'm saying is, considering you see a total situation that quickly, and you're gonna' type anyway, shoot, go ahead and fix said situation....your friend, mule.....

 

[mtrycrafts]

.....Mtrycrafts, your thinking is, "if I never give answers, the audiophite will be encouraged to dig on and learn"....that's it, isn't it?....not trying to rile you up, and I appreciate much, your demeanor in responding to me thus far.....

Why would I want to rile you up or down?
after all, you are a member in good standing here; so am I and like to keep it that way?
We are not discussing the of fate of the planet as if we had the means to follow through So, it is just a discussion place for our area of interest.

 

[Stepheng]

Buckeyefan 1,
My setup is a 5.1 system. Polk Rti's and SVS PB12 Plus/2. The Bijou looks great, might incorporate it down the line. Thanks.

Mtrycrafts,
Either I didn't phrase my thoughts well, or you misunderstood my point about the Rti 12's. If I remove the metal jumpers from the binding posts then the speaker is essentially a 8ohm speaker. Add the jumpers and you have a 4 ohm speaker. Therefore, if I biamp, each channel of the amplifier only has to power a 8ohm load, not a 4 ohm load, right? Also, the Rti 12's have a 90dB efficiency, which seems to be middle of the road fo sensitivity.

AVRat,
From what I have read on this and other forums if you can have close to the same power going to all your speakers, the better the sound. So, I was thinking I would do a 200w or 300w multi amp. and have the center and surrounds powered the same. I spoke with the Polk rep. and he said 300w would not hurt the Csi5 or the Fxi5's, provided I don't max them out, which I never would. Also, the Sunfire Cinema Grand makes it rather simple to biamp, just dasiy chain the RCA interconnects to the different channels with the preouts and do the necessary speaker connections and viola. I'm considering the Sunfire b/c of space issues, but want to make sure the amp matches well with the speakers and AVR. Any other amplifier and I'll have to get creative in its placement (on top of the SVS?)

 

[AVRat]

Let's take this in stages.

From what I have read on this and other forums if you can have close to the same power going to all your speakers, the better the sound.

It's not about power going to the speaker, it's about sound pressure level (SPL) being heard at the listening position. You want an even SPL being heard from all the speakers for a balanced effect. High and low efficiency speakers are going to produce different SPLs given the same power. It is definitely easier to balance SPLs with equally powered amps and speakers of similar efficiencies.

the Sunfire Cinema Grand makes it rather simple to biamp, just dasiy chain the RCA interconnects to the different channels with the preouts and do the necessary speaker connections and viola

If only it were that simple! The crossover network of the speaker provides two functions.
1.) It routes frequencies to the appropriate drivers
2.) It distributes power appropriately

By deciding to bi-amp the speaker, you are taking over the power distribution duties. If you get the distributon wrong, the speaker will be unbalanced. Giving each section of the speaker the same amount of power may not provide the best solution. There is some simple testing you can do now to see if equal distribution is appropriate. It is best done with an SPL meter.

Unless you have a very LARGE room, the Sunfire Cinema Grand 200~five should provide plenty of power. And being that the Rti 12s are 4 ohm, it will provide them with 400W and offers a decent bi-wire option.

Hope this helps.

 

[j_garcia]

Each section of the speaker doesn't NEED the same power. The mids/tweet don't need as much power as the midbass/bass drivers. I'm with AVRat on this one, leave the jumper in place and send those guys a single channel of clean power, use an SPL meter to adjust all your speakers and it will sound great.

Now, here's another question: are you running them large or small? IMO, despite them being towers, they are not full range speaekrs and cannot handle bass as well as the SVS can, so I would have them set to small with the lowest x-over available on your receiver. Sending them a full range signal means you are missing some of the bass below their -3dB point of 30Hz.

 

[AVRat]

I concur with J_Garcia regarding the sizing issue. Unfortunately, I believe the Yammy 2500 uses only univarsal crossover settings. I would suggest you first run the YPAO auto setup and see what your first impressions are. If you're not satified with the result, then you can start tweeking the system to your liking.

 

[MacManNM]

[Not at all. Actually it will be more difficult as now you will be driving a much lower impedance drivers, so it is harder on the amps, especially when you start out with a 4 ohm speaker and will end up with around 2 ohms on each channel.

Not true, when bi amping the polks the, Z actually goes up, not down. It will be easier on the amps and it will sound much better.

 

[MacManNM]

Bi-amping the polk speakers does not bypass the the internal crossover. I believe all that you really need is one 2 ch amp to power the low end of your mains. The 2500 has more than enough power to drive the rest of the system with it's internal power amps. Don't waste your money on a 7 ch amp, it's simply not going to improve anything.

 

[Stepheng]

AVRat and J Garcia,
What you're telling me makes sense. I'm all for keeping it simple. If driving the mains with a single channel at 4 ohms will sound as good or perhaps better than biampping then that works for me (cheaper than a seven channel amp).

I currently have the Rti 12's set to small and x-over at 60hz. The Yam. 2500 only has universal x-over setting, so I'm stuck with tweaking, trying to find the right x-over for all my speakers. The YPAO sets the x-over high IMO, like 160 or 200hz. I get different results with YPAO's x-over, so I manually set it. Also, on the Yam 2500 you can set the bass out to sub, both or front. Would it help the rti 12's if I set the bass out to "both", instead of "sub"?

McmanNM,
I've read that 130w from an AVR is not the same as say 200w form a seperate amplifier. The seperate amp will produce a better sound b/c of the current along with the added watts. I'm not able to test or demo different amplifiers (2 channel v/s 5 channel), so I'm trying to make my best judgement on what I read and learn here and other places before I decide to buy.

I am curious about the QSC RMX 2450 amplifier that Mulester 7 has spoke about and wonder if that might work well with the Rti series and the yamaha 2500

 

[MacManNM]

AVRat and J Garcia,
What you're telling me makes sense. I'm all for keeping it simple. If driving the mains with a single channel at 4 ohms will sound as good or perhaps better than biampping then that works for me (cheaper than a seven channel amp).

I currently have the Rti 12's set to small and x-over at 60hz. The Yam. 2500 only has universal x-over setting, so I'm stuck with tweaking, trying to find the right x-over for all my speakers. The YPAO sets the x-over high IMO, like 160 or 200hz. I get different results with YPAO's x-over, so I manually set it. Also, on the Yam 2500 you can set the bass out to sub, both or front. Would it help the rti 12's if I set the bass out to "both", instead of "sub"?

McmanNM,
I've read that 130w from an AVR is not the same as say 200w form a seperate amplifier. The seperate amp will produce a better sound b/c of the current along with the added watts. I'm not able to test or demo different amplifiers (2 channel v/s 5 channel), so I'm trying to make my best judgement on what I read and learn here and other places before I decide to buy.

I am curious about the QSC RMX 2450 amplifier that Mulester 7 has spoke about and wonder if that might work well with the Rti series and the yamaha 2500

Any amplifier you get, that is a good amp, is going to sound better. Unless the amp is being driven beyond its limits (which you are doing now using the receivers amp) you aren't going to notice a difference in the sound. Most of the tonal qualities are introduced in the preamp section.

That amp will work well, I would also recommend the Mackie 1400i, with either of these amps you wouldn’t need to bi-amp the speakers. Most of these receivers have a current limiters in them, this is why your speakers will seem to lack bass and control. Don’t forget your Polks are really 4 ohm speakers which changes the sensitivity to 87db, not 90 as the spec sheet says.

Edit: Don't forget that just because you biamp the mains, the internal crossover is still in use. Any settings for your surround wont change them. I would reccomend setting your unit to sub, not both, then crossing over around 45 Hz or so (using the external amp).

 

[Stepheng]

MacmanNM,
Thanks for the information, I'll check out the Mackie and try the sub option on the bass out.

 

[MacManNM]

MacmanNM,
Thanks for the information, I'll check out the Mackie and try the sub option on the bass out.

Good luck, I hope it ends up sounding great.

Buck has been playing around with this for a while, he hasn't gotten an amp yet, so he just disconnected the lower portion of the mains and increased this crossover.