Why does my low wattage amp seem more powerful than my higher wattage amp?

[Mumstead]

Here is my situation. I have a low wattage (20wpc) class A solid state Luxman integrated amp, the L-550AX. My speakers are B&W 805S and are their sensitivity is 88dB. Everywhere I read that B&W speakers need as much power as you can give them to sound their best. I think that they sound amazing with the Luxman but I thought that maybe I was missing out on something so I purchased a Parasound HALO HINT 6 (180wpc). I know that this isn't gobs of power but it is a lot more than 20wpc.

The strange thing is the Luxman seems to drive my speakers much more effortlessly than the HINT 6. I noticed when I first set up the HINT 6 that I really had to turn it up high to get a similar volume. I had to have the HINT 6 at 80 (out of 100) on its volume to get similar volume that I get with the Luxman's volume at about 30%. With the HINT 6 I could even max the volume out, it was way to loud to be comfortable but it was possible. With the Luxman I could never turn it up past 70%, it is just way too loud.
The Luxman seems to drive my speakers, for lack of a better word, better that the HINT 6. There is more bass and transients seem to be faster and have more impact with the Luxman. I have swapped both amps back and forth and listened to the same music and there is definitely a difference. Now I'm an older guy that went to way too many rock concerts in my youth so I definitely don't have golden ears but even I can hear the difference.

What is going on here? Why does this this 20wpc amp seem so superior to me and drive my speakers so much easier than the 180wpc amp. Can I assume that it will be able to drive other speakers with approximately the same sensitivity as well as it seems to drive my B&Ws? I'm considering selling the 805S for a pair of Revel F208s which are slightly more efficient. Can I expect similar performance from my Luxman with these speakers?

 

[jhaider]

Check the input sensivity on the Parasound.

 

[DonH56]

For volume the preamp's level depends upon the gain of the power amplifier. In other words you cannot judge power by the position of the knob.

A low-power class-A amplifier likely has much higher distortion than the more powerful amplifier, and typically second harmonic distortion is the highest component. It may also have a higher noise floor. And of course the lower-powered amplifier will clip much sooner. The result is that the lower-powered amplifier may indeed sound louder, but it is primarily due to noise and distortion, alas.

IME/IMO/blah blah blah - Don

 

[restorer-john]

I would expect the Lux is conservatively specified. Note the doubling of rated power at 4 ohms. We all know this is to impress audiophiles, but usually the 8 ohm spec is under-rated to give the impression of 'doubling down'. Not only that, Lux is usually conservative on all specs, so the 4 ohm rating is likely conservative too.

your Lux amp: http://www.luxman.com/product/detail.php?id=3

Your Parasound amp

According to the specs, the Lux is considerably quieter in terms of noise, lower in distortion than the Parasound and based on my interpretation of the specs and visuals of the units, I wouldn't be picking the Parasound as the one to use. The Lux will always be more in demand and retain a greater percentage of its initial cost. It's more attractive, likely to test extremely well, appears well built and should last you many years.

That said, the Parasound appears no slouch either. Why did you pick it by the way?

Your B&W speakers dip to 3.8 ohms from a nominally rated 8 ohms too so the differences in absolute maximum SPL won't be as much as you might expect.

I would expect the Lux to perform admirably with the more efficient speakers, but it would probably be a good idea to try before you buy if you can in your own lounge room.

 

[maty]

[Polish] https://audio.com.pl/testy/stereo/wzmacniacze-stereo/949-luxman-l-550ax

to English: https://translate.google.com/translate?hl=&sl=pl&tl=en&u=https://audio.com.pl/testy/stereo/wzmacniacze-stereo/949-luxman-l-550ax

LUXMAN L-550AX

• Rated power (1% THD + N, 1 kHz) [W] 8 Ω, 2x 61
• Rated power (1% THD + N, 1 kHz) [W] 4 Ω, 2x 114
• Sensitivity (for maximum power) [V] 1x 0.14
• Signal-to-noise ratio (A-weighted filter, with reference to 1W) [dB] 90
• Dynamics [dB] 107
• Damping factor (relative to 4 Ω) 106

[ Looking at the factory data, it is hard to admire the declared power; 20 W at 8 ohms and 40 W at 4 ohms ... only the most ardent audiophiles, believers in "louder and quieter watts", humor will improve the declaration of work in class A.

Fortunately, our laboratory measurements reveal that the "550" does not end up at the above values, and confidently, passing smoothly to the AB class, delivers about three times more - 61 W at 8 ohms and 116 W at 4 ohms - and the result in two-channel mode it is practically unchanged, thanks to the power supply efficiency. Luxman can work with the vast majority of columns.

In contrast to the competitor, the "550" has a very high sensitivity - just a voltage of only 0.14 volts to get the maximum power. The voltage gain is therefore very high (as much as 156 V / V), and yet the device boasts an excellent signal-to-noise ratio - up to 90 dB. ]

SS amps, max power better at 0.1% THD. But since Parasound offers it at 0.9%, it is OK to compare. And at 0.05% 160 watts/8 Ohms.

If the true sensitivity is 88 dB/W/m (manufacturers tend to exaggerate/lie) you have enough power with 60 watts / 8 Ohms. Well, if you do not listen to music very far!

 

[maty]

Luxman must works as class A up to 20 Watts / 8 Ohms. After works as class AB.

If you like class A sound, better idea speakers with higher sensitivity than 88 dB/W/m if you listen to good/very good recordings with high dynamic range (DR). I guess you have not spent the money to listen to the current bad commercial music, with low/very low DR.

https://www.doctorproaudio.com/doctor/calculadores_en.htm#calc_spl

-> Calculators/Audio/Acoustics/SPL

Distance to speaker?

 

[Blumlein 88]

So the Luxman is similar to an early Classe DR3 HC I once owned. It was listed as 30 wpc class A. Yet in reality it was about 220 wpc class AB and capable of very high current too (that was the HC).

Contrasted with a Pass Aleph 0 which was 30 wpc class A and capable of no other class of operation. Rather current limited as well. The amp could sound good, but you had to be picky, picky about the load or you'd run out of either current or power and it sounded icy, hard and horrible in short it was simply distorting.

 

[cjfrbw]

Yes, it is not unusual for robustly built push-pull class A designs to have as much as 4-5db of power overhead going into class AB and probably 1 or 2 db more of transient power.
Here's the performance envelope of Accuphase A20v, also a nominal class A 20 watt push pull design.

Single ended will be close to the stated power output without much overhead and lower power with lower impedances.

 

[Mumstead]

Wow, Thanks for all the info! I knew that this was the place to ask about this. This is without a doubt the most informative audio forum on the web.

To answer a couple questions, I picked the Parasound because the original HALO integrated got great reviews and I got a smoking deal on it.
I sit about 7 feet from my speakers so according to the linked calculator that would be 97db at my listening position at 20wpc.
I do listen to well recorded high DR music. The brickwalled crap drives me crazy. I expected the Parasound to sound better because it would have more power in reserve but that is just not the case. Listening to the same music at the same volume you would swear that the Luxman has more power.

The Luxman is a beautiful piece of equipment. It is built like a combination of a fine watch and a tank. I only need one of these amps and it is the one that I want to keep. It sounds terriffic to my ears and I think it could be "the last amp I'll ever need" (yeah right). My B&Ws sound great with it but I want some floorstanding speakers with more/better bass. Does anyone have any suggestions? My absolute limit is $5K.

 

[DonH56]

Revel would be my suggestion, but if you like the B&W sound, why not look to their line? 700 series tower maybe?

 

[Mumstead]

I'm not necessarily saying I'm a fan of the B&W sound. I just don't have a lot to compare it to. There are basically no audio stores in my area any more. Most of them closed up when the economy went belly up a decade or so ago.
I've had Paradigm Studio 20 V2, Emotiva ERT 8.3, Martin Logan Vista, and B&W 805S.
Out of all of them the Martin Logans were my least favorite. I sold them for the B&Ws which are more to my liking.

 

[infinitesymphony]

Maybe the SVS Ultra Tower speakers would be up your alley with the built-in 8" woofers. They appear to be built similarly to some of the best passive floorstanders I've ever heard, Boston Acoustics VR975, though the latter speakers had 10" woofers and additional 12" passive radiators. They didn't lack bass.

 

[Mumstead]

Does anyone have any experience with Focal Aria 948s? They are efficient and, from what I have read, like high current which my Luxman has. I just don't know much about their speakers but I love my Elear headphones.

 

[Alexanderc]

Does anyone have any experience with Focal Aria 948s? They are efficient and, from what I have read, like high current which my Luxman has. I just don't know much about their speakers but I love my Elear headphones.

The focal aria 906 tested well here. No guarantee that the 948 will be as good of course, but it’s promising at least.
https://www.audiosciencereview.com/forum/index.php?threads/focal-aria-906-speaker-review.14085/

Someone here will say that for $5k you should get the Revel f208 (at a discount) or 206 and add a pair of subwoofers. I’m sure they will be right about maximizing the performance if you have the floor space and inclination. I’m leaning this direction myself

You might also consider Kef r7 or r11 as speakers one might expect to measure well based on the r3 that was measured on this forum.
https://www.audiosciencereview.com/forum/index.php?threads/kef-r3-speaker-review.12021/