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Post by DavidR on Apr 8, 2022 8:35:52 GMT -5
"Okay, fine. What about this 350W rating into 4 ohms? Why doesn’t it double into 4 ohms? I thought that was good. Here’s a horrible truth: no amp doubles its output into 4 ohms. None. Nada. Zip. Some might get close, but when you factor in transformer resistance and saturation, choke resistance, emitter resistance (especially in a differential amplifier where that’s 2X a factor), then an actual doubling into 4 ohms aintgonnahappen.com. So what do you folks in the Lounge think about this? Schiit is saying that NO amp doubles the output from 8 ohms to 4 ohms, yet I've seen specs for various amps, including Emo's HC-1, that show a doubling of the watts from 8 to 4 ohms." Of course it can be done if the manufacturer chooses to over engineer enough to do so and to understate the 8 ohm power specification slightly so that the double at 4 ohm can be realized. Most manufacturers want to publish the absolute maximum power rating at 8 ohms, however. It's probably easier to do with a SWPS type power supply because of the lack of an expensive large transformer.
I believe it has to do with the design of the amp and some of the components. I've seen many amp specs where the watts double.
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KeithL
Administrator 
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Post by KeithL on Apr 8, 2022 10:20:17 GMT -5
Yes, no, sort of, and not so much... I would certainly agree that most modern amps don't deliver twice the power into 4 Ohms that they do into 8 Ohms... And, yes, Schiit is somewhat prone to a bit of hyperbole in their advertising... but they do make cool products.
In theory, since most modern amplifiers are voltage sources, they "should be" able to deliver twice as much power into a 4 Ohm load as into an 8 Ohm load. However, that is assuming that their output power is limited by their rail voltage, and they can both deliver unlimited current and dissipate the power required to do so indefinitely.
In reality.... - An amplifier that is limited by its power rails, but that can deliver unlimited current, and dissipate unlimited power, would deliver twice as much power into 4 Ohms as into 8 Ohms... - An amplifier that is limited by current, which includes some early amps with "current protection", will actually deliver HALF as much power into 4 Ohms as into 8 Ohms... - And an amplifier that employs impedance matching, as with tube amps that use output transformers, will deliver exactly the same power into any output impedance (as long as its transformer has a tap for that impedance)... - Real world modern amplifier designs, without output transformers, are optimized to be most efficient at full power into a specific impedance - and will be at least somewhat less efficient into any other impedance. (This is even true of Class D amplifiers... although it can be reduced to being more or less insignificant with careful design.)
In marketing terms saying that an amplifier can "double down into 4 Ohms" do so is simply a claim that it is "super heavy duty and massively overbuilt".
(It's very much analogous to that TV commercial that shows a sports pickup truck towing a house down the street.)
It's also worth remembering that the manufacturer gets to pick how they describe their gear and what specifications they choose to publish.... Let's assume that we build an amplifier than can actually deliver 100 watts into 8 Ohms and 150 watts into 4 Ohms ... I can obviously rate it as: "100 watts into 8 Ohms and 150 watts into 4 Ohms"... Or I could rate it as: "75 watts into 8 Ohms and 150 watts into 4 Ohms"... (Notice how, with the second rating, the power does double into 4 Ohms.)
And it's also worth remembering that amplifier power ratings are based on the ability to deliver power continuously long term. (So, if that amplifier really could deliver 200 watts into 4 Ohms while playing music, but would eventually overheat if I asked to do so on a bench test, I can't rate it at "200 watts".)
And, finally, remember that all of these numbers are more variable than many people seem to think... For example the real impedance of a typical 4 Ohm speaker will vary between about 2.5 Ohms and 10 Ohms or so at different frequencies...
And the real impedance of a typical 8 Ohm speaker will vary between about 5 Ohms and 20 Ohms or so at different frequencies... So there's really not much point in obsessing over minute details like this anyway...
Our HC-1 was designed "to be able to deliver massive amounts of current if necessary to ensure that it would have no trouble driving even very difficult loads"... That's far more significant than the fact that it can specifically "double down into 4 Ohms".
"Okay, fine. What about this 350W rating into 4 ohms? Why doesn’t it double into 4 ohms? I thought that was good. Here’s a horrible truth: no amp doubles its output into 4 ohms. None. Nada. Zip. Some might get close, but when you factor in transformer resistance and saturation, choke resistance, emitter resistance (especially in a differential amplifier where that’s 2X a factor), then an actual doubling into 4 ohms aintgonnahappen.com. So what do you folks in the Lounge think about this? Schiit is saying that NO amp doubles the output from 8 ohms to 4 ohms, yet I've seen specs for various amps, including Emo's HC-1, that show a doubling of the watts from 8 to 4 ohms." Of course it can be done if the manufacturer chooses to over engineer enough to do so and to understate the 8 ohm power specification slightly so that the double at 4 ohm can be realized. Most manufacturers want to publish the absolute maximum power rating at 8 ohms, however. It's probably easier to do with a SWPS type power supply because of the lack of an expensive large transformer. |
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Post by Soup on Apr 10, 2022 17:30:31 GMT -5
Now that I am back in the office what internet radio player and stations do you recommend for Android? Thanks for your responses.
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Post by DavidR on Apr 27, 2022 9:54:21 GMT -5
 anyone want to take a guess what this is ? |
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Post by graphic on Apr 27, 2022 10:49:56 GMT -5
<button disabled="" class="c-attachment-insert--linked o-btn--sm">Attachment Deleted</button> anyone want to take a guess what this is ?
Does Dr. Amar Bose ring a bell? |
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Post by marcl on Apr 27, 2022 10:50:01 GMT -5
Been out of the loop since March 31. Two week birding/photography tour in Costa Rica, tested positive for Covid at the airport April 17, 7-day mandatory hotel quarantine, sketchy regulations for certificate of recovery to fly home ... got out Monday the 25th! No health issues and only very mild cold symptoms a few days two weeks ago. Culled 17800 photos down to 6400 for final review while I was "in the can". Just hangin' out at home now   |
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Post by foggy1956 on Apr 27, 2022 11:56:58 GMT -5
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Post by DavidR on Apr 27, 2022 12:59:26 GMT -5
<button disabled="" class="c-attachment-insert--linked o-btn--sm">Attachment Deleted</button> anyone want to take a guess what this is ?
Does Dr. Amar Bose ring a bell? Yes
It's the 2201. Some say a predecessor to the development of the 901.
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Post by graphic on Apr 27, 2022 14:35:37 GMT -5
Does Dr. Amar Bose ring a bell? Yes
It's the 2201. Some say a predecessor to the development of the 901.
If I recall, this was pictured in Dr. Bose’s ‘White Paper’ that I read back in 1968, on his research with a ‘radiating sphere’ and how he got to the 901 design. Seemed, even then, a big step from there to the 901. Even more interesting tidbit is his link to the DCM Time Windows design and their ‘father’ Steve Everbach (sp). |
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KeithL
Administrator
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Post by KeithL on Apr 27, 2022 15:52:27 GMT -5
He's cute... and nice shot! Been out of the loop since March 31. Two week birding/photography tour in Costa Rica, tested positive for Covid at the airport April 17, 7-day mandatory hotel quarantine, sketchy regulations for certificate of recovery to fly home ... got out Monday the 25th! No health issues and only very mild cold symptoms a few days two weeks ago. Culled 17800 photos down to 6400 for final review while I was "in the can". Just hangin' out at home now  <button disabled="" class="c-attachment-insert--linked o-btn--sm">Attachment Deleted</button> |
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KeithL
Administrator
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Post by KeithL on Apr 27, 2022 16:06:35 GMT -5
Bose 2201.... According to this it was the first speaker Bose made... and the next one was the 901 (which I never liked... but they did make a great PA speaker if you turned them around). (Excellent article if you like industry history.)
And, if you put it in a corner, it should be a near perfect spherical radiator (into a 1/8 sphere space).
(But only at pretty low frequencies... at above several hundred Hz the wavefront will look more like a coronavirus than a sphere.  )
Note: I was too lazy to read the entire article... but I do agree with what I think they were saying. Bose is an excellent engineering company. Their products are well designed, well made, reliable, relatively intuitive, and seem to do exactly what they're supposed to do.
They simply put most of the things on that list higher in priority than sound quality. (I never had a wave radio - but I did have a pair of their second-gen noise cancelling headphones - and they worked perfectly.)
<button disabled="" class="c-attachment-insert--linked o-btn--sm">Attachment Deleted</button> anyone want to take a guess what this is ?
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Post by DavidR on Apr 27, 2022 17:23:47 GMT -5
Straight from the Bose archives and coming to a store near you.
The Bose SPHERE (and with all the usual hype)
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Post by DavidR on Apr 27, 2022 17:32:48 GMT -5
Bose 2201.... Note: I was too lazy to read the entire article... but I do agree with what I think they were saying. Bose is an excellent engineering company. Their products are well designed, well made, reliable, relatively intuitive, and seem to do exactly what they're supposed to do.
They simply put most of the things on that list higher in priority than sound quality. (I never had a wave radio - but I did have a pair of their second-gen noise cancelling headphones - and they worked perfectly.)
Don't get one. My wife has one and my first impression was, hmmmm, not bad.......BUT after about 20 to 30 minutes it got and still gets 'under-my-skin' (a.k.a. listener fatigue). |
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Post by vcautokid on Apr 28, 2022 18:26:05 GMT -5
 My virtual game upped. Chair coming Monday! |
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Post by vcautokid on Apr 28, 2022 18:29:09 GMT -5
 Work headsets suck on comfort. Used Grado replacement pads on mine. Much better. |
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Post by DavidR on Jul 13, 2022 10:00:45 GMT -5
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Post by DavidR on Jul 15, 2022 19:31:36 GMT -5
Any of you experienced this >>> |
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hemster
Global Moderator
Particle Manufacturer
...still listening... still watching
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Post by hemster on Jul 15, 2022 22:34:24 GMT -5
Any of you experienced this >>> Yes!! Every time I get a Subway sub or Chipotle bowl! |
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klinemj
Emo VIPs 
Official Emofest Scribe
Posts: 15,094
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Post by klinemj on Jul 16, 2022 7:13:04 GMT -5
Any of you experienced this >>> Yes - most of the burgers look like someone stepped on them. And, if I order a single cheeseburger at Wendy's w/my usual toppings - there is almost always more mustard on the outside of the bun than inside! Mark |
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Post by novisnick on Jul 16, 2022 12:25:09 GMT -5
Any of you experienced this >>> I can’t recall the last time I’ve been to a fast food restaurant, years ago! My memory recalls these type of examples. These are actual pictures of the food at my restaurant, No photoshop here!    |
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