Emotiva Lauch Basx (Gen 2) Amps

Thatsnotmynaim

Distinguished Member
One thing also is speaker specs are largely a sham based on marketing nominal specs at best.
Some speakers rated at a nominal 8 ohms, can dip as low as 3 ohms meaning you needs to factor in worst case scenario for power not average or highest ohms.

Another phenominon not well pubished or understood is phase angle, this is to do with cross overs and the draw the speaker cones have of watts vs current. Nothing to do with speaker placement and 180 degs etc like subs. Phase angle when perfectly right will be 0 degs, meaning current drawn is bang in line with watts drawn, meaning it can easily be calculated. Howver some hard to drive speakers do not have linear phase angle of 0 degs, the worst phase angle being 45 degs, which if a speakers has this at a given frequency, the speaker will end up drawing double the current for the given watts being drawn. What this means is that a speaker that draws only 50w normally at 0 degs phase angle, when the phase angle is 45 degs then the current being drawn at that point is equivelent to double the current that would normally be drawn. So 50 watts draw at 45 degs, could put a current draw on the amp equivelent to a 100 watts draw at 0 degs phase angle.

This in summary means a speaker that is rated at 8 ohms nominal and would normally need say 50 watts to create the spl at your given listening position, if the ohms drops to say 4 ohms could draw 100 watts and if this was at the exact time, phase angle for your speakers was the worst 45 degs, would draw current equivelent to a 200 watts amp.

Kef R700 are rated at 8 ohms, but dip as low as 3.2 ohms right at the point phase angle goes out of shape at 45 degs.. 50w = 125w due to 3,2 ohms, = 250w due to 45 degs phase angle..

914KEFfig1.jpg


It's not all linear so is hard to say exactly, but more power and specifically amps with more stable current delivery at low ohms = better sound, usually means better PSU and Capacitors as well as highly rated amp modules.
 

Thatsnotmynaim

Distinguished Member
Have look at emotiva xpa series just a few caps on psu for many channels probably due to instant power from smps
Yes smps is different as they work much faster I think
 

Thatsnotmynaim

Distinguished Member
Also one other thing on speaker specs is that most technical tests of amps are generally done into a fixed ohm load, usually a fixed resistor or resistors, this is not representitive of a real speaker load which is generally anything but a stable fixed load. This will give you an idea of how an amp will technically function into a fixed say 8 or 4 ohm load with a 0 degs phase angle, but not how it will perform into a dynamic load in terms of ever changing ohms and phase angle. The changing of the load itself can be as tricky as the actual load being harder. It's a bit like driving a car on a rolling road at a single speed to see how fast it goes, it tells you nothing of how it will drive round bends and up and down hills.
Speakers that dip and have tricky loads can sound ok with nominal power but often sound much better the more power you throw at them which can be higher than their specs suggest, often due to the high current draw not pure watts draw..
 

Dobbyisfree

Active Member
In summary, @Mr Wolf to make your spreadsheet a more accurate simulation it would need to be a giant simulation programme needing a supercomputer to process :)

More seriously though, the general advice on AVF is a bit of "more power the better" but, at the same time, there needs to be some realism to it.

I would say if you've reached a point where you can barely hear a difference, you've gone slightly too far, and the last upgrade was where to stop. But no one knows where that point will be.

For certain, using an ancient 5 channel power amp on pre outs for me is a huge difference to using the AVR's amps. To me that means one more step would probably be worth it. But another step after that? Probably not.

TBH, there's a lovely Rotel 1095 ending this evening on the 'bay which I'd love to have but even with the new hifi rack it's too big for "only" five channels. I believe two 1.2kVa toroids and eight 15,000µF caps!
 

Mr Wolf

Active Member
It's not all linear so is hard to say exactly, but more power and specifically amps with more stable current delivery at low ohms = better sound, usually means better PSU and Capacitors as well as highly rated amp modules.
This makes a lot of sense to me. Is it fair to say then that a manufacturer may choose to include a greater amount of capacitance in its design to enable the amp to be used with more difficult to drive speakers (i.e. taxing load/phase angle)? I can see why this would make commercial sense. If so, does it therefore follow that if you're running on AVR capacitors (like me) then it's probably wise to stick to easy to drive speakers?

I'd interested to get your thoughts on my B&W L/R mains (2.5-way tower with a 90dB sensitivity rating) in terms of whether an external power amp would bring much to the party at my listening levels. This is Stereophile's impedance/phase plot...

1626953479423.png


...and this is what they said about it:

"The handsome B&W DM603 S3 has higher-than-average voltage sensitivity, at an estimated 89dB(B)/2.83V/m. Though this is slightly lower than the specified 90dB, the difference is not that significant, given the usual experimental error. The speaker's impedance plot (fig.1), however, indicates that it is a moderately difficult load, at least at very high frequencies, where the magnitude drops to 3.1 ohms at 15kHz. Fortunately, music has very little energy in this region, and at low frequencies the speaker remains above 4 ohms."

Based on their sensitivity rating/distance, at my listening level I've estimated that the peak amplifier demand from them is no higher than 12W (on an 8-Ohm basis) so in a 4-Ohm dip that might be as high as 24W.
 
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Dobbyisfree

Active Member
The speakers that I've used as fronts since 2017 (which will now be surround speakers) are:


You kindly included these in your spreadsheet for me. They report a 91dB sensitivity.

So to answer your question though (this is using my ears and brain, not electronics):

With an AVR-x2300, and I'm not making this up, I was disappointed in the speakers. They sounded "held back". I was convinced that this wasn't a fault of the speakers and, a while later I tried both an AVR-x3100 and a Marantz SR5006 which both "opened up" the speakers. The next AVR that appeared on the doorstep (playing the "people who sell stuff but don't know its value" game) was an AVR4310. They were like new speakers.

My AVR (required for 4k) step up was an x3600 which seemed as bad using its amps as the 2300 to be honest not much difference (which was weird as it seemed worse than the x3100). But when I plugged the Rotel RB985mkii in it, it was immense. I'd like to add that still for music didn't sound as nice and capable to me as the AVR4310 but maybe that's Denon's demeaning AVR musical ability who knows?

Whether this is all due to the ability of the power amps in each case (and I guess the best comparison was with the x3600 as it was the same pre-amp) I do not know. But you can see the impedance graph.

I've never tried my x4400 as pre-amp with the Rotel and Q900s. I don't want to, as I'd be upset that the Q900s are now surround speakers!

If you're asking me (and I know people on here don't like subjective assessments) if you, for example, plugged that RMB1095 that I mentioned above your DM603 would sing like you've never heard them before.

But my recommendation could be wrong, and you could end up with a very heavy door stop (and a lot of spare capacitors!).
 

Mr Wolf

Active Member
My AVR (required for 4k) step up was an x3600
Feature wise maybe, but amplification wise that was a massive step down for you. The 4310 was from Denon's "Battleship AVR" era of 2008-2010 when they had massive PSUs and heatsinks - the thing was beast compared to today's offerings. S&V tested the 4310 at 114W/105W with 5/7 channels driven at 0.1% THD - that's easily up there with the X8500.

My Yamaha RX-V3900 was from the same model year and, being a very similar price, was a direct competitor to the 4310 and is also a fairly meaty build.
 

Dobbyisfree

Active Member
Feature wise maybe, but amplification wise that was a massive step down for you. The 4310 was from Denon's "Battleship AVR" era of 2008-2010 when they had massive PSUs and heatsinks - the thing was beast compared to today's offerings. S&V tested the 4310 at 114W/105W with 5/7 channels driven at 0.1% THD - that's easily up there with the X8500.

My Yamaha RX-V3900 was from the same model year and, being a very similar price, was a direct competitor to the 4310 and is also a fairly meaty build.

Are you trying to make me cry? 🤣

I loved it.
 

Thatsnotmynaim

Distinguished Member
Tend to agree and you can also then upgrade the faster changing tech pre-amp / AVR whilst the power amp will last for years......
 

Dobbyisfree

Active Member
@Mr Wolf you've pretty much had three answers to your question in post 81. I'd say you need a new thread (and link it) if you want to open up the question to more members.

I really recommend that you ask if someone can lend you a PA to try, you could offer to collect or pay postage. Many members have spare kit!
 

CableGuy

Active Member
Lol. I’m so lost. Anyone want to chat about Emotiva BasX series. ;-)
 

Mr Wolf

Active Member
Lol. I’m so lost. Anyone want to chat about Emotiva BasX series. ;-)
Yes, I have a question for you about your new A3.

I've seen your video review (well done by the way - great production values IMO) and wondered what sort of volume levels you're listening at given you perceive the 7011 has less punch?
 

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