[zybar]

Unfair to the store?

The HiFi shop by me constantly lends out gear, you have to get on a waiting list!

Since most of it is synergy, it’s almost impossible to buy something without trying it out.


BTW: this company called http://www.fatwyre.com/ started out selling new and used cables and they lend them to you. Not they also sell components and they lend them too.


My amp is 1.8 wpc. I drive a 95db sensitive speaker. I have used my old trusty RatShack sound meter and found that 82db is the normal listening volume to me. High 80’s is kind of loud.
Unless you listen to very dynamic music types (orchestra), the wattage needed is very low. Hundreds of watts even for a very inefficient speaker is hard to justify in the real world – maybe on paper but that’s not worth much.

Sounds like the Audio shop wants to sell you an amp.


My buddy borrowed a MF amp and a Parasound at one point, didn’t like either.

I said it was unfair to the store if you have no intention of possibly buying the gear from them.

I am a 100% believer in checking out gear in your own system.

Most of the time I accomplish this task by buying something used and trying it out.  I go this route instead of going to the dealer and asking for an audition because I have no intention of paying a dealer's asking price.

George

[Russell Dawkins]

What's to stop you going back to the store where they recommended the MF KW 750, borrowing it for a day and finding out for sure if that's the answer?

If you like the result you could then start looking for that much power in a solid state amp but cheaper.

What you suggest seems quite unfair to the store.

Why should they lend out gear to somebody who has no intention of purchasing the gear, but only wants to hear if it is the answer?

People should only use the dealer if they might actually purchase what they are auditioning. 

If you want to hear the gear AND pay below dealer prices, buy it used (here at AC, Audiogon, etc...) so you can try it in your system.  This will provide less financial risk and not take advantage of the dealer.

George

I guess you are right.

I hadn't realized the KW 750 costs $15,000, but I did get the impression that the dealer was pushing an expensive system and should allow a home demo. As you say, though, it would be unethical on the buyer's part if there were no possibility of purchase.

To the extent that the dealer is pushing it, though, a home demo should be allowed, even it requires purchase to prove ability to pay.

I have taken gear home on a dealer's insistance, thinking there was no way I would buy it because I had just bought a more expensive 3 times as powerful amp (20 years ago - Mission Cyrus I vs NAD 120 watter) and kept the loaner. The dealer was right.

[warnerwh]

The best route imo is to buy used gear off of Audiogon. If you don't like it the loss is small if any.  I did that for a long time and learned alot in the process. Trying different gear in your system can be fun too.

[nathanm]

My room is 20 ft wide by 30 ft long with 8 ft ceiling, pretty large area.

Gosh, what a terrible burden this must be!  Because I am such a nice guy, I would be willing to trade my room for yours.  Where do you live?  It's no problem, my room will fit in the back of a pickup truck!

[jon_010101]

I have 90dB/1W 4 ohm GR Research Diluceos.  To date, I've never been able to push even 1W into them in my small apartment.  I got a cheap monster tripath amp (200WPC) recently with power meters, and I need earplugs before it hits the 1W mark (85dB+ is where I give up). 

My 12W tube push-pull amps offer more than enough power for me (and sound way ballsier than the tripath, interestingly enough).

[chgolatin2]

Purchase a Jolida 1000RC and I am totally happy with next in the near future and nice mods will be done but until now I dont need massive wattage power just pure bliss of 100-150 wpc from my tube integrated...

[TONEPUB]

Since I got my CJ premier 350, I've been enjoying the big amp.  A lot more
dynamic and open than when I was listening to 40-60wpc amps...

It's all speaker and room dependent though...

[1000a]

when its loud i play my 100 watt x 2 tube amp pp at 11 > 1:00 vol. position which is usually plenty loud, never much past 2:00pm.

I have no idea what the wattage it is pushing at that stage, I am starting to believe even at that level it may only be low watts on average but when the peaks in the music come which is all about attack and transients I am sure it digs very deeply into its substantial remaining watts just for Milli seconds mind you but I want lots of head room when it needs it so the climax's, peaks, crescendos are not compressed in any way.  from what I understand which is limited.   to be able to reproduce music realistically, its not in the averages they are handled easily by most gear, the problems start when the music demands a lot of power to represent the peaks with out running out of juice.  when it does things get compressed quickly.

this does not mean a 3-12 watt amp has no head room it just has to be used with very efficient speakers as where my amp does not I can use less efficient speakers.  with my speaker choices I really like a good 70-100 watt x 2 amp.  If I enjoyed high efficiency ones all that power would not be necessary and I could select a SET amp which many consider more refined than a PP. but like everything there are pros and cons to both, no one amp does every thing really well.

like OJ we need cars that can go 180 if the heat is on , but mostly we drive around 60-65

please let me know if this is essentially correct.

thanks in advance.

[djbnh]

Honestly speaking do you really need that much power to drive your equipment?  I was under the impression that 100 up to 300 watts should be sufficient enough for anyones listening needs, especically you like to crank it up from time to time like I do???

I feel the answer to the above is dependent to a good extent on the speakers being used. For example, I own a pair of older Polk SDA-1Cs that are quite efficient, but truly sing with high current amps. [I note that I too like to crank it up from time to time.] The Polks were paired way back in the day with a NAD amp that had plenty of watts but no where enough current (The Polk tweeter protectors would come into play at louder than normal, but not thundering, listening levels; this occurred even after the tweeter protectors were replaced). After I upgraded to a pair of Odyssey Extreme mono amps, I found that the Polks respond effortlessly at all volume levels and all's well. YMMV.

[Lacee]

The last power amps I owned were 1000 watt mono blocks.

The latest power amp is 2 watts.

The speakers have remained the same, and I can honestly say that I have never felt that I lack any power or volume with the 2 watt SET amp.

I listen at moderate levels in a moderate sized room with 90 db speakers.

I really think the need for high power gets overplayed.


Some of my most beloved power amps were also the least powerful.

I tend to side with those who prefer quality over quantity.

[JLM]

Rules for sizing power amps:

1.   Need enough to provide a commanding grip on the speakers (better resolution, safer for drivers to over drive with clean power than sending them a clipped signal).

2.   Think in terms of dB’s of gain, not watts (takes 10 times the wattage to add 10 dB, which sounds twice as loud).  So the number of watts vary very widely.

3.   Typically accepted peak spls – jazz/classical 105 dB, rock 110 dB (but some reference sources would bump that up by as much as 25 dB!).

4.   Subtract your chosen peak spls from your rated speaker efficiency (matching both for the same ohms rating of your speakers), that will be the minimum dB of gain you’ll need (remember rule #1).

5.   Add for bigger rooms (“average” is about 2,000 cu. ft.) and/or the farther back you listen (up to another 10 dB).

So reaching rock levels with 80 dB/w/m @ 8 ohm speakers in a 10,000 cu. ft. room (a very big residential room) could require (using the above absolute worst case) at least 60 dB or 1,000,000 wpc!  At the other extreme, to reach 80 dB with 100 dB/w/m @ 8 ohm speakers in a 1,000 cu. ft. room (a tiny room) could only require 0.005 wpc.  So you can see why the advice you get can vary widely.

Keep in mind that most audiophiles I know typically listen at levels around 85 dB.  So the average speaker/room can reach typical levels with about 1 wpc (without a commanding grip).

[PDR]

Maybe a better analogy would be flying in an ultralight compared to a Cessna....
You only need 30hp to get up in a ultra.......you need a lot more for a Cessna.
Once your up in both, your flying.
The question is.....should you take lessons before you buy a plane and try to take off.

[Russell Dawkins]

If ever you have to fly in challenging circumstances, though - like in the mountains - a big surplus of power at hand is your best friend.

[PDR]

If ever you have to fly in challenging circumstances, though - like in the mountains - a big surplus of power at hand is your best friend.

He he......yep, but hard to take in the view at 800 mph....

[Russell Dawkins]

I was actually referring to the survival aspect! There can be horrendous downdrafts in the mountains - adiabatic winds are one source - and the only way to survive (if you are close to the surface) is to have a ton of surplus power at hand to power through it.
I think of this as an obscure variation on the need for headroom.

[Rclark]

I got my pilots license some a long time ago, kind of stopped doing that but always planned to get back. Actually, always wanted to try a glider..

 ... A friend of mine is one of those few people piloting a wingsuit, if you've ever seen those videos.. Lifelong skydiver. I could never see jumping out of a perfectly good plane though, and there are too many stories of failed gear. At least in a plane you have a chance to glide down and land.

[clpetersen]

Now that's just common sense - along very good and practical advice.

This is from a post on similar thread in the AVS forums:

The answer is 'it depends'. It depends on what you listen to. If popular music, with almost no dynamic range currently (just Google 'dynamic range music' to see dozens of mainstream articles talking about dynamic range compression), then a low power amp will be fine. In the uploaded chart, a recent Metallica album had 3dB of total dynamic range (!).

But lets say you only want to reproduce the range of a cassette tape from 1960, about 55 dB of range, before even Dolby. You have a normally quite room, about 50 dB of background noise is typical, and you sit 2 meters (~7') from your speaker, which has a sensitivity of 91 dB. (91 dB at 1 meter, for 1Watt of input energy). {{This is a pretty efficient speaker, but looking at conversions of sound pressure to watts you will see that the speaker is less than 4% efficient - electrical input to sound output; which is pretty typical.}}

 Continuing: So 55 dB range creates a sound level in this case of 50 db Background +55 dB range or 105 dB. This is a very loud sound, hopefully just a transient. 14 dB over 91 dB (@1 watt), requires 25 watts of power at 1 meter listening distance.

Derate to 2 meters listening distance ( twice the distance = 4 times the needed power), and you need ~100 watts/channel to play the full range of a 1960 cassette. 3 meters and you need 225 watts. Say you wanted to hit just 100 dB max volume at a 2 meter distant couch, which is loud. Then you would need just 30W/channel.

But again, most popular music has only 10-15 dB of range (at most), so it depends. I believe (not an expert) most 'really good' classical recordings can have about 50 dB of range, and some audiophile ones might be 60-70 dB.
 
Yes, every 3 dB is twice the power, and the sound level decreases as the square of the distance. so 4 meters away is 1/16 of the sound pressure (volume) at 1 meter.

Most listening is done at less than a watt; it is the transients and range (and listening position) that drive the power requirements.


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[Wayner]

Most listening is done at less than a watt; it is the transients and range (and listening position) that drive the power requirements.

No, it's not that at all. It's all about speaker efficiency. Then it's about the room size and what listening levels you listen to. Almost every one of your statements is wrong, IMO.......

[RDavidson]

No, it's not that at all. It's all about speaker efficiency. Then it's about the room size and what listening levels you listen to. Almost every one of your statements is wrong, IMO.......

I don't think so, Wayner. Look at headphones. They barely need any power. Know why? They're right next to your ears, not because they're efficient or inefficient. So you're partially right. Room size is important to consider, BUT how much power one needs to reach certain SPLs  (at the listening position) depends on how close or far the listening position is. It isn't like the sound from our speakers shoots straight into our ears (from more than a foot or two away), the way it does with headphones. One could have a HUGE listening room, but if they only sit 2-3 meters away, they may not need tons of power. You only need tons of power if you're trying to energize the entire space. Also, power requirements DO depend very much on how dynamic the listening material is. Even if a person sits 2-3 meters from their efficient speakers, if their amp doesn't have enough headroom, and they love listening to classical at high levels, transients will surely be blunted. There's no opinning around this stuff.

[Pneumonic]

You need enough power (amongst other things) to drive the speakers that are housed in your room, to the desired volume you enjoy while playing the music you wish, without clipping.

Since the variables above are so many, it's impossible for anyone to tell you what is the correct answer in your particular and specific case. What's really needed is for you to measure your amp's output to see if you ever clip it under the above conditions. Not practical for most people to do unfortunately. If it were, I suspect more people would realize that they run underpowered amps.