Loudspeaker Compatability

[DonFF]

I'm in the market for 2 floor standing speakers, and narrowed it down to a pair of Infinity P362 or Paradigm Monitor 7s. My center channel is an Infinity as well. It's a 5.1 system and will be powered by an Onkyo705. Any problems with either towers? I believe the tweeters are all the same type. Thanks for your help.

 

[TLS Guy]

I'm in the market for 2 floor standing speakers, and narrowed it down to a pair of Infinity P362 or Paradigm Monitor 7s. My center channel is an Infinity as well. It's a 5.1 system and will be powered by an Onkyo705. Any problems with either towers? I believe the tweeters are all the same type. Thanks for your help.

Both speakers state they are nominally 8 ohms. However the infinity is known not to be and has very low impedance dips. I suspect the Paradigm does too from the driver configuration. I would advise external amplification. I don't know if that receiver has pre outs. If you do go the receiver route, make sure you have one with pre outs.

You might want to look at this thread started today.

 

[mazersteven]

I would advise external amplification.

You have got to be kidding me. External amplification for a set of Paradigm Monitor 7's, and Infinity P362's.

Explain this reasoning when both speakers have a high sensitivity.

 

[TLS Guy]

You have got to be kidding me. External amplification for a set of Paradigm Monitor 7's.

Explain this reasoning.

Well sure enough, I dug up an impedance curve for the Monitor 7s.

Sure enough they are to all intense and purposes 4 ohm speakers just like the Infinity. They are 4 ohm speakers below 400 Hz except for the LF tuning peaks. Any 2 1/2 way design has to be unless you want the HF impedance 16 ohms. The real power is below 400 Hz where the impedance drops to 4 Ohms as the lower driver shelves in.

So a receiver designed for 8 ohm loads will give only half its rated power into either of those speakers and be stressed.

I guess we have very different standards. The standard of driving either of those speakers with that type of receiver is not on my radar screen.

 

[mazersteven]

Well sure enough, I dug up an impedance curve for the Monitor 7s.

Even the article you linked stated "Impedance ranges between just above 4 ohms (150 Hz) to about 38 ohms (2 kHz), indicating that the 7 should be easy to drive."

And with the Onkyo 705 able to handle a 4ohm load, I don't see the need for an external amp.
http://www.onkyousa.com/model.cfm?m=TX-SR705&class=Receiver&p=s

Plus your digging up an article on the v2 Monitors. Monitor v5's are out now.

 

[TLS Guy]

Even the article you linked stated "Impedance ranges between just above 4 ohms (150 Hz) to about 38 ohms (2 kHz), indicating that the 7 should be easy to drive."

And with the Onkyo 705 able to handle a 4ohm load, I don't see the need for an external amp.
http://www.onkyousa.com/model.cfm?m=TX-SR705&class=Receiver&p=s

Plus your digging up an article on the v2 Monitors. Monitor v5's are out now.

I wish life was that simple. The impedance curve is very typical of any 2 1/2 way tower. You have to look at the curve. There are two narrow bass peaks which every properly tuned ported or TL speaker will have. Then there is a rising tweeter impedance on the top end. However where the significant power is, they are largely 4 ohm. It is the minimum impedance below 500 Hz that is the most meaningful number to pick when deciding on the impedance a speaker will actually present to an amp. It is always worse than that anyway, because of the power factor (phase relationship of the current and voltage).

The Onkyo only gives peak power specs into four ohms 1 channel driven! That inspires huge confidence doesn't it? The members going with the trend to just use receivers as pre/pros are heading in the right direction.

Anyhow moving to pre/pros and powered speakers should be the wave of the future. Receivers are yesterday's gear or should be.

 

[jostenmeat]

I'm in the market for 2 floor standing speakers, and narrowed it down to a pair of Infinity P362 or Paradigm Monitor 7s. My center channel is an Infinity as well. It's a 5.1 system and will be powered by an Onkyo705. Any problems with either towers? I believe the tweeters are all the same type. Thanks for your help.

Well, since you have the Infinity center already... I would go Paradigm if you really, truly, preferred them. So much so, that you are willing to get a new center, at least eventually. Otherwise, if they are pretty close in your estimation, go Infinity.

The 705 has preouts, and can matrix the hi-def stuff if you ever have 7.1. If TLS has scared you yet, you can always add an amp at any time. The need for more amp, in addition to TLS' warnings, also include two big factors: volumes you want to obtain & distance you sit from speakers.

Have fun and good luck!