How much amp overhead is enough? KEF 105.4 + AMP??

Monad

Monad

Super Member
I'm looking for a new amp, trying to spend under $500 right now. Currently running Schiit Freya >> Bose 1800 Series VI (a white-labeled Carver PM1400) >> out to KEF 105.4s.

I'm trying to understand how much amp I need.. been looking at Yamaha M, MX, P series from 120wpc up to 350 as well as similarly aged and situated amps with pretty meters and lights. I'm a sucker for meters.

If I went with a Yamaha M4, 120 wpc, am I going to be bummed? Does something around 150-170 wpc get me there?

I get it, the answer is subjective and based on multiple/ myriad factors..

What I'm asking is, based on your personal preference, if you were me (while thanking goodness and any deity that will listen that you are not) what would you all do, in this situation?
 
Thee Carver is rated at 450 watts per channel 8 ohms. You might get buy with 300/per. Other wise you will perceive a big difference.
 
It will all depend on your speaker's efficiency, power curve and how loud you intend to play them. A pair of Klipsch speakers with an efficiency of 102db/W/m would need a lot less power than a speaker of the same impedance with an efficiency of 86db/W/m for the same output. A 120W/ch amp with the Klipsch' will probably never need the headroom, where with the speakers with the 86db efficiency may. I've always heard to get as much power as you can afford. I also don't like running an amplifier at its extremes. It may run at its extreme specs for a while, but components change with age and when you're running at max the difference in component values may cause a premature failure. Heat from running at max also causes component value drift and eventual failure.
 
If that Carver power rating above is correct - you should be OK with what you have.....

I am running equally power hungry 104.2's with a sansui AU-999 - thats only about 75W or so per channel. But unfortunately I am never able to turn them up loud.... )-:
 
Speakers are 86dB 1W 1m pink noise.
The speakers are designed to notify when they receive 200 watts.
The speakers are designed to use up to 200 watts.
The speaker are designed to hit 108dB peaks which is 256 watts peaks for that pink noise.

But we don't know how loud you want to listen or if the music is bass heavy, two critical tidbits of information for determining power requirements.

I use some 85dB 1W 1m speakers with either 200 wpc ss or 50 wpc tube and the tubes make plenty of noise and sound better doing it.

Since it takes 10 times as much power to make it twice as loud, one burns up power but quick when you go up in volume over a 100 wpc amp.

I'd say the highest quality power you can buy and as that quality goes up the power might come down some but if you want those speakers to sound their best, get good sound quality. If you want em loud just get 500 bucks worth of Crown power and enjoy.
 
I'm running my Kef 105/4's with a Sony STR-GX10ES (150wpc) they sound really good .In fact GREAT!!!
 
I use one of these (Sony TAN77es 200+200@8) most of the time and if I feel the need for more power, I hook up my 2nd one and run them as monos in BTL. (>580+580@8, >750+750@4).

77es.JPG

Nice big meters. :)
 
Hi5 4 MMMMMMmmmmeeeeters!!

thank you for the responses. the only real trouble i have with the current amp is the fan noise, which I can hear, or possibly imagine I hear, at lower levels. When the music stops, I'll be working on something and not notice immediately-- but then the fan wakes me out of my occupational sleepwalk, like sand paper v sunburn and I have to rush over to turn it off or put something else on.

I used to like loud music, I think but mostly for the bass and less the highs. Shrill highs w high volume = fast fatigue onset.. In response, I've been trying to define/ discover the lower end volume setting, where I'm still getting good sound out of the speakers..

In any event, the more hours I listen in a day, the lower the volume gets.

I've been looking at some Klipsch models as a second or primary set of speakers, so I can really enjoy boom of rock and metal, that I'm not getting from the KEFs.

Mostly, I've been listening to straight ahead jazz, classical and minimalist stuff (Blakey, Brubeck, Kraftwerk, Tomita..) .. I seem to be addicted to Kraftwerk Autobahn, have played it every day this week, at least once.. had Judas- Sad Wings o' Destiny, today with morning coffee.

A friend suggested replacing the fan on the current unit.. which sounds like an easy (too easy, possibly a trap) fix. The unit doesn't run hot ever, even after being on all day, but the fan also runs 24/7 when its switched on.
 
500 bucks will buy you a lot of amp if you shop wisely and exercise a little patience. I'm a big fan of HK Citation amps, and I picked up my Citation 22 and the 16 for less than 400 bucks each. The 22 pops up on ebay from time to time relatively cheap but the 16 seems to command a lot more money. There isn't a lot of info on the old interwebs about the 22, but it is a really, really nice sounding amp and it has plenty of punch.
 
kfalls said:
Heat from running at max also causes component value drift and eventual failure.
Click to expand...
I thought common (Class AB) amps ran hottest at 1/3 power, thus the FTC requirement for 1/3 power preconditioning for an hour before testing.

Blue Shadow said:
Since it takes 10 times as much power to make it twice as loud, one burns up power but quick when you go up in volume over a 100 wpc amp.
Click to expand...
Thinking about amplifier power in watts is misleading. Probably intentionally misleading, since it allows manufacturer's to make mountains out of molehills in their advertising. Convert watts to dBW, see how amplifiers compare.
 
I rn my 107's with a McCormack DNA 0.5 (200 wpc @ 4 ohms). I'm quite happy. Curious about more power? Sure. The sound QUALITY is outstanding though! I am a big fan of Class A amps!
 
Back when Roger Russell was designing his first series of speakers for Mcintosh, he took some test equipment and went out and measured sound levels at different venues. Like KEF he determined that 104 to 108 db was all that was necessary to produce live concert sound . Paul Klipsch did the same many. years earlier. But he chose to use the front row as the desired listening position and as a musician we wanted to produce the maximum levels of a Grand Piano as experienced by the pianist at the key board. So he chose 115 db. Ed over at AR new folks didn't listen that loudly so his speakers could only reproduce about 98 to 100 db at rated power of 35 wats. Three different ideas. Ed was right of course most folks listen at 85 db and with digital tech enology with 95 db peaks. So two AR-3a can produce that with 100 watts each about 109 db together at 4 ft or 99 db at 10 ft apex. More than enough. Now professional musicians and music producers, engineers and the like push the envelope about another 6 db. Or 100 db peaks. which means their speakers need to put out 110 db. Which the KEF's match, as do Snells, Magico, Mac and others, in fact most of todays speakers. But there are always a few listeners who prefer for Paul's path, and to produce those levels is where the rub comes in. Mac uses line arrays to keep the distortion low control the dispersion and reduce acoustical energy loss. Paul uses very sensitive horns , now with exotic material diaphragms and new horn control technology to deliver the desired result. Some manufacturers like Magico and B&W hope you sit closer while designing models that can handle 1000 watts at less than 2% over most of the spectrum. To reach the full spectrum in the S line you need supplementary subs to reach Paul's levels. But as there are very few folks that listen at those levels, subs are not needed for stereo reproduction. Your Kef's are fine. But if you want big in your face sound, and don't want to break the bank, Horns are the only economical answer, if you can call 12,000 or 15,000 dollars for the conventional or latest new Cornerhorns economical. You can be perfectly happy with a 120 watt amplifier, however. Personally I would rather spend the money on the speakers than on big amps. Having to buy 1200 watt Power amps is not my idea of fun. Though my favorite audio amps for auditioning speakers at any power level are either the MC 1201/1.2k...
 
I once built corner horns capable of 126 dB peaks without clipping, when bi-amped with two 80 watt amps (G.A.S. Grandsons). That kind of volume was fun for about 2 minutes at a time when I was twenty years old. I cannot understand anyone actually preferring to listen at that volume long term. @twiiii, from dozens of posts, you seem obsessed with it, almost to the exclusion of other criteria. That is probably only my incorrect impression, but I am sure from several threads that many, many audiophiles here are quite satisfied with much less than those kinds of sound pressure levels. Even @Judas Priest seems to mellowing some as he discovers classical music. Why the emphasis on maximum volume? Just curious...
 
I have definitely mellowed out a bit as I get older. I still love Rock and Metal, but I just can´t take extreme high volume for very long, and I want to preserve the little hearing that I still have.

When I listened to Rock on New Years Eve, my max peak was 105 dbA at the listening position, and I think that was just for one song. Average listening for the rest of the evening was at around 90-95 dbA, which was pretty loud.
 
Speaker ratings are a very confusing issue for most of us. It would be nice if they were all referenced to a specific standard. Even the Germans with their Din standards can't seem to use a single standard. Today we don't know if. a manufacturer is rating his speakers to peak power, average power or RMS continuous power. We also don't know if the rating power was for the full spectrum or a limited one. IS the sensitivity at one watt or 2.83 volts, they are not always the same. And is the band width a full band width or a single tone or an abbreviated bandwidth. Our changes in tastes of music have forced Manufacturers to rethink their designs and there fore to change how they present their new products with meaning full specifications defining the new capabilities of the speakers that consumers will understand. Something else manufacturers don't tell is their speakers are not linear. The may perform just fine at 1 watt 10 watts but by the time the reach 100 watts the woofer can't move enough fast enough accurately enough to maintain the same balance they do at 25 or fifty watts. JBL built many different woofers back in the 70's and 80's, Some could take great amounts of power but weren't linear. PA guys loved them because they did not fail when over driven and the sound was so loud if there was a little compression there was no big sacrifice. Some of their home speakers were very efficient and very linear, l but could only handle limited power. Folks began swapping the HP versions with their consumer models and wondered why the sound changed significantly when the system was pushed. Fortunately we have progressed passed the 70's and 80s's where the CD put a lot more strain on speakers. When HT came along Dolby new most consumer speakers weren't up to the task so he settled on dividing up the spectrum to protect the satellite speakers and installing subwoofers. Very few folks wanted to go back to Patricians, Concert Grands, Klipschorns, and Hartsfields or Harness, or Carmel's and Magnificants. They were just too big and very expensive. Manufactures were able to convince folks the they could build a smaller speaker with a smaller foot print that could do the job. If it couldn't there was the life savor, the subwoofer. I have heard some great miserably sized loudspeakers, but they take some much power today. Fortunately. we still have. choices. Good luck with those choices. Remember if there is any way to do so, don't confine your self to small SPEAKERS. You don't have to go large either.
 
There are some good amp/watt calculators on-line to get you in the ball park.

You do need to have an idea of how loud you like to listen, the distance from the speakers to your listening spot, and you can add in your own desired value for headroom(power reserve).
https://www.extron.com/product/audiotools.aspx

Pick the tab along the top for amp power.

I go conservative and do two runs for a 3dB headroom and a 10dB headroom to calculate amp power needed. Then get something in between.
 
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