Why all amps and receivers aren't the same. (1 Viewer)

[Chu Gai]

You could, but it's pretty time consuming to get it all to come out right. Adding a sub, even if the mains are full range, allows you to place the sub which reproduces the low frequencies, in a more optimum position. This location is invariably not the same place as where your speakers are.

 

[Seth=L]

I know how time consuming it can be, But I think it is worth it. Conider that placing doesn't cost you any money, only some time. Not everything is perfect, but I am going to try and get the best I can with what little I do have.

 

[Arthur S]

Jeremy

You're right. Reference level is insane in the home. Have you listened to white noise at 85 db, it is hard to take. 75 db is more than adequate as a base. I have some experience with amps with watt meters using reasonably efficient speakers. Output levels of 0.1 watt-0.5 watt produce comfortably loud listening levels in a good sized room. By maxing the bass tone controls, and louder listening level, I was able to get the power output up to maybe 2-5 watts. With modern bass management sending >80Hz to the subwoofer, the demands on receivers are minimized. 100 watts per will do in most environments. Of course, for those who can really stand reference level, it is a different story.

Seth

You confused me because of your 5 channel Carver amp. I have some good speakers that can go strong to 32 Hz. But it wasn't till I got a subwoofer that I could achieve the results I wanted in the deep bass for stereo, let alone HT.

The market for stereo receivers is practically dead, what with HT receivers starting at $110. There has been a small resurgence of interest in higher priced stereo recievers. As far as I know they don't have bass managment, but, if this is true it is a shame. Receivers today are good enough to use for both HT and stereo, except for those who truly want a minimalist stereo system.

And, as Chu pointed out, even with speakers flat to at least 25 Hz, it is easier to get the bass right with a sub, though there certainly those who prefer all the sound to come from the mains. My brother-in-law has 6 foot Martin-Logans and they simply can't do justice to truly deep bass.

Careful with those crescendos, I don't want to read any more blown speaker stories

 

[Seth=L]

looked at Outlaw's newest creation, 100 watts per channel, bass management, and for $599 you can have one. It has an awesome look to it, very retro, but very cool.


I know that you can acheive pretty good volume using only a few watts, which is why am debating tube amplifiers, I just don't like hearing strain of amplifiers running out of juice at high volumes. My Onkyo's would run out of musically satisfying juice, where I have yet to have my Carver run out on me.

 

[johnADA]

I dont know how to explain it, but the differences between units and the sound when they rate out at the same wattage and no sonic tonality was given to them, is torque.
Sorry to use a car term, but thats what I've thinking and dont know enough about the electrical end of it.
Watts we can call horsepower and you can have all the horsepower in the world, but still wouldnt be quick. Kinda the muscle car against the Rice burner, the muscle car had no problem launching, pulling wheels etc, but the Rice burner just cant match it, but in the long haul can be just as fast.
I think it applies to amps as well, some just dont have the torque to drive low frequencies at louder volumes so they go bright and lose some sound against ones that dont have a torque problem.
So under car terms, a low wattage amp with alot of torque can more than make up for the high wattage, weak torque causing a sound difference!

 

[JeremyErwin]

Please, you're making my head hurt. Analogies are what lawyers and politicians use:

Physicists have math.

 

[Seth=L]

I thought that was a very good comparison, John.

And Jeremy, what are you talking about. I haven't the slightest clue as to as what your point is here.

 

[JeremyErwin]

Sigh. I suppose I'll have to dig out Halliday and Resnik.

Analogies have their limitations.

 

[Seth=L]

Fine, I will just pretend to know what you are talking about, insert knod and look of intense interest here_______.

I would rather listen to a 10 watt tube amp over a 200 watt Onkyo, why because it is better power. Just the same, The Carver I have has a better 80 watts per channel next to an Onkyo's 100 watts per channel. If you can't notice the difference, then you don't need to invest in seperates (though I don't consider my seperates investments, more just strokes of luck). I wouldn't recomend that my grandpa buy seperates but rather a simple HTIAB that is reliable. It sounds better than TV speakers, that is good enough for him. I wouldn't recomend seperates to most of my friends for simplicity and they don't desire more than what they already have. If they are satisfied with Sony receiver, I am not going to tell them it is worthless because it's ratings are false. If your wants are met, then there wouldn't be much reason to upgrade. I always want more, so I go through lots of equipment. That is just me.

 

[JeremyErwin]

A simplification.
Power=Voltage^2/2*Impedence.

So, for a 40 Volt amplifier, we have
1 ohm 800 Watts
2 ohm 400 Watts
4 ohm 200 Watts
8 ohm 100 Watts

But, Watts are equal to Current * Voltage

1 ohm 20 A
2 ohm 10 A
4 ohm 5 A
8 ohm 2.5 A.

If the electronics (most obviously the power supply) can't handle the additional current demands, they overheat and die.

The most appropriate analogy, as far as it goes, is to think of the circuit as pipes of pressurized water feeding, oh I don't know,-- how about a fountain. Obviously, the fountain needs both pressure and water. If there's no pressure (akin to voltage) the fountain fizzles. If there's no water (akin to current) the fountain fizzles, and the pumps overheat...

There are flaws in this analogy, and some of those flaws may well obscure the actual physics. But since I'm not so eager to relearn whatever I've forgotten about alternating current circuits, it will have to do for now.

 

[Arthur S]

Seth

Tubes are well regarded because they produce euphonic harmonic distortion that is pleasing to the ear. Probably even-order harmonics. They also are much more sensitive to impedance variations during the interactions between speaker and amp. Transistor amps generally produce more odd-order harmonics that are not as pleasant to the ear. So, tubes may sound sweet, umm, because they are. That is not the same as identical to the original source.

If I was really interested in tubes, I would look for a used Sunfire amp. Some of them have a switch which has a voltage position for tube sound, and a current position for the more accurate, but different sounding solid state sound.

 

[Seth=L]

I understand now, thank you Jeremy.

I am now remembering this stuff from Physics. So if a stereo amplifier is rated to output 100 watts per channel 8ohms, and has an input of 700 watts or 5.8 amps. then it is reasonable to assume the amplifier can handle speakers with 4ohms and output 200 watts per channel?

 

[Seth=L]

I have heard that the Sunfire amps had a tube like sound. Maybe this is why their subs aren't that great. I know the tube amps don't repoduce accurate sound, at least to the source, but regardless they do sound beautifull.

I think if, I remember correctly the singel ended triode amps are one of the most difficult to integrate amplifiers out there, and the maintanance on those things is unbeleivable. If you have a High End turntable and cartridge with it, you may as well just quit your job to maintain the setup.

 

[JeremyErwin]

Depends on the class of amplifier. If it's class A, the theoretical efficiency is 50%...

 

[Seth=L]

I will have to do a study on different classes of amplifiers.

I was doing some test listening today and found that my Infinity IL10 bookshelf speakers can handle about 30 watts on extended continuance. The suitable amplifier range is 15-150 watts per speaker. So that likely means the stats would say the have a music handling of around 80-100. So it would seem even speaker power ratings are bloated.

 

[Arthur S]

Correct

Maintenance on tube equipment is a pain, not to mention bias adjustment, tube harmonics, etc. That is why the Sunfires with the 2 position switch, for tube sound, or solid state sound, are a good way to go for anyone who wants to dally in tube and still have solid state, all at the flick of a switch. I would not make any generalizations about Sunfire amps. One thing I will say is that the Cinema Grands are some of the highest powered, coolest running, lightest amps anywhere, and for this reason, they are used at Audio Shows to demo some pretty good HT systems. 5-7 channels X 200 watts (much more into 4 ohms), and less than 47 pounds. They are killer for HT use.

 

[Seth=L]

My dad has one, and it does pack a serious punch and it mellows down his Klipsch speakers as well. I think the reason they are so light is they don't have a power transformer and use the AC current dirrectly as their subwoofers do.

 

[Arthur S]

I think they do have a power transformer, but it does not have to be a large one. That is one reason they are so light. The other reason they are so light is because they do not have to have heat sinking, because they are a variation on switching amps. In fact there are not even any cooling slots on the top of the amps! Think Bash, think Panasonic 10 pound receivers, like XR57, and the like.

Your dad knows what he is doing!

 

[JeremyErwin]

I came across this website the other day. Just though you might get a kick out it.


I guess this means that for your long winter listening sessions, you can turn off that rackety furnace, and just enjoy the warm sound.

 

[Chu Gai]

If you want to mimic what Carver did with the 'tube sound', add something like a 4 ohm high power resistor to your speaker wires and listen to the difference.