XPA-7 Gen3 Or XPA-11 Gen3?

[rhett]

budget！ budget！ budget！

That is the reason I ask this  funny  question.


I have Energy 5.1 Take Classic Home Theater Speaker System home now.

Now planing to buy a Goldenear TRITON TWO+ speaker. It looks like I could not buy a whole set of Dolby Atmos 7.1.4 or 5.1.6 system in once.

Even new set of 5.1.



I am planing buy TRITON TWO+ first, and step by step， but I could not know how long , SUPERCENTER XXL, SUPERSAT 50.



Base on my research, emotiva XPA would be the best Amplifier for the performance and budget .



Now XPA-11 Gen3 has same price with XPA-7 Gen3. I only need XPA-5 now.



Should I buy XPA-11 Gen3 ? how would it be?

[pknaz]

I think you should start with how much power you need per channel to achieve the SPL requirements you have. I'd start there. I've posted quite a few times in the last few weeks about power requirements and how to calculate them.

[simpleman68]

Nov 12, 2017 11:17:58 GMT -5 pknaz said:

I think you should start with how much power you need per channel to achieve the SPL requirements you have. I'd start there. I've posted quite a few times in the last few weeks about power requirements and how to calculate them.

Agreed; that's about a simple and helpful answer you can get.

Last night I switched off my 2 back surrounds off and used my XPR-5 to drive the other 5 speakers. I noticed a substantial attenuation of the L and R speakers which I removed from the XPR-2.
I had to bring the volume up almost 6 on the processor to match the previous setup.

I think the XPA-6 to 11 is a great solution for surround speakers but prefer a dedicated amp for the L/C/R speakers. Even with more efficient speakers it makes a difference.
My JTR Noesis are 95 dB efficient and I noticed a substantial difference.
Scott

[leonski]

Even though all watts are not created equal, I'll still agree that Most HT speakers are not a difficult load from the electrical standpoint.

Going straight for the watts is not necessarily productive. Capability enters into the mix, too, and considerations like end use (Movie / Music mix %) and how loud you like it.

A very capable amp will provide more real power to a given speaker than many amps rated for higher power into a dummy, resistive load.

I wish it WERE as simple as calculating power from SPL desires and speaker sensitivity.

[pknaz]

Nov 14, 2017 18:02:44 GMT -5 leonski said:

I wish it WERE as simple as calculating power from SPL desires and speaker sensitivity.

Can you show any examples of where this is not the case?  Esoteric discussions aside, given the context of the OP's question and his options presented?

[leonski]

Good and fair question:

Please read thru this link for some information.

ALL amps which measure the 'same' (let's be fair and say 'within reason') into a resistor vary wildly into a real, reactive load.
As voltage and current go 'out of phase' when driving a reactive load, power delivered is the Cosine of the angle.

I might add that few testers measure amps using this system.     Let sleeping dogs lie, is the accepted wisdom.

audiograph.se/wp-content/uploads/2013/12/PowerCube_12p_brochure_complete.pdf

So, an amp which may measure (again mythical) 100 watts into an 8 ohm RESISTOR may measure far worse into a real, speakers reactiance.
Some very expensive amps fail this test while other more modest stuff does surprisingly well. Tube amps with the transformer are another Can-O-Worms altogether, with problems involving the
amp not liking either Capacitive or Inductive loads (can't remember which)
Part II of the speaker reply is that there are No Standards for a reactive speaker dummy load. A quick Google will show you several good suggestions but amplifier manufacturers Ignore this.

And finally? How much do Speaker designer/builders and Amp designer/builders really talk? Not much, I fear. Though for the HT guy, it isn't awful.

The Good News is that the majority of HT oridiented speakers are not a really wacky load. This is to the advantage of HT receivers which have notoriously mediocre amps, especially when
presented with sub-8 ohm loads.

This is one of the major sources for amps 'not sounding the same' since they don't all drive the same load with the same ability.
And some speakers, like maybe Thiel and B&W are 'difficult' loads to drive based on large phase swings with large phase angles.

This may actually be a better way to present speaker impedance and phase data on ONE chart. Its called a Smith Chart and usually used by the microwave guys.
The curly-Q line is the speakers measure. Where is crosses the horizontal center line is pure resistive. One end of the line is 20hz the other end maybe 20khz.
IN GENERAL, the closer to the center line, the 'easier' the load. Each circle generally represents one 'way' of a multi-driver speaker.

hometheaterhifi.com/technical/technical-reviews/a-secrets-technical-article/