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Is this acurate?

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GSB
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Read this reply to a question:Is 70watts ok to drive my speakers.( American av site.)

Is it acurate?

 

If you ever reach more than 30 watts I'll be shocked They are very efficient at 90db at 1 watt. So, 70 watts... 1=90db 2=93db 4=96db(already to "tv watching" volume) 8=99db (THX reference volume for watching movies) 16=102 (starting to get painful) 32=105 (hearing damage) 64=108 (perm hearing damage) Reduce the DB by 3db for every meter beyond the first one. So at 2 meters away... 1=87 8=96 at 3 meters 1=84db 8=93 Not exact on the numbers as the room greatly affects the volume of sound. Give you a rough idea. Lets say you are listening from the next room (kitchen while these are in the living room...eh, in my home is roughly 5 meters) and you still need to hear your cell phone. You probably are using somewhere along 8watts, so you won't drown out your cell phone ring tone. And even then, at 5 meters pushing 8 watts, you'll still hit the mute button.

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RE: Is this acurate?

GSB wrote:

Read this reply to a question:Is 70watts ok to drive my speakers.( American av site.)

Is it acurate?

 

If you ever reach more than 30 watts I'll be shocked They are very efficient at 90db at 1 watt. So, 70 watts... 1=90db 2=93db 4=96db(already to "tv watching" volume) 8=99db (THX reference volume for watching movies) 16=102 (starting to get painful) 32=105 (hearing damage) 64=108 (perm hearing damage) Reduce the DB by 3db for every meter beyond the first one. So at 2 meters away... 1=87 8=96 at 3 meters 1=84db 8=93 Not exact on the numbers as the room greatly affects the volume of sound. Give you a rough idea. Lets say you are listening from the next room (kitchen while these are in the living room...eh, in my home is roughly 5 meters) and you still need to hear your cell phone. You probably are using somewhere along 8watts, so you won't drown out your cell phone ring tone. And even then, at 5 meters pushing 8 watts, you'll still hit the mute button.

It might be close to being accurate, but is only part of the story. If you like your music at more than moderate levels and especially if you have a larger than average listening environment, then 30 Watts is likely to fall short unless using some extremely sensitive/efficient speakers.

There's no substitue for 'cubes' as they say.

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RE: Is this acurate?

I've said this for years.  And on this forum, too, before now.

I've got a 25W Cyrus One knocking around here unused.  It was my main amp when I bought my Mission 794s two years ago, and in my 15'x12' room it'll easily make my ears bleed before it even thinks about clipping or running out of gas.

All the guys who say that's not enough, wow I'd love to know what levels they listen music at.  Or what concert-halls they live in.  Or do they just have insensitive speakers. Or maybe they're just plain mutton-jeff.

At what I call comfortable listening levels in my room with my speakers, I really don't think any amp would be pushing out more than 5-8W RMS p/c at the very most.

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RE: Is this acurate?

Not sure I agree, I've had an oscilloscope connected to a 50wpc amplifier while listening and it clipped, I don't have permanent hearing damage after the experience either. 

BigH's picture
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RE: Is this acurate?

Have you seen an amp with clipping warning lights on it, surprising how often they light up even at moderate levels. The thing is it is constance noise like a hammer drill but music has some peaks that require lots of watts.

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RE: Is this acurate?

I have used lots of amplifiers in my current room ranging from 2w to 200w and never heard an amp clip yet. Some of those being a 2wpc SET, 6wpc SE, 10wpc PP and 15w SE valve amps into the same 80dB speakers and never have any issues with loudness or distortion yet.

Also speakers ranging from 78db to 95dB.

Maybe a lot of people listen a whole lot louder than I do or have MUCH bigger rooms.

 

I would have thought what most people hear as clipping is actually distortion from the speaker drivers rather than an amplifier itself clipping.

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RE: Is this acurate?

It all depends how many dbs you listen at. And how efficient your speakers are. And how far you sit from them.

 

How many dbs do you listen at Overdose? As in loudest peaks. How loud are they? And if you put your sound meter 1 metre from your speakers, how many dbs do you measure on peaks?

 

For example, at the moment I'm listening at my normal late evening levels. Peaks are at 62dbs at my listening position. 72dbs 1 metre from my speakers. That equates to peaks of one hundredth of a watt throught my 92 db/2.83v/1m efficient speakers.

 

For loud blast, home disco party levels I might go up to peaks of 95dbs in the room, that's 105dbs at 1 metre. I use my biggest, most efficient speakers for these, which are 102db efficient. So, that's peaks of 2 watts through them. Not much is it? If I were to use 85 db efficient speakers for these parties I'd be peaking at 100watts.

 

At a recent music festival I was sitting 5 to 7 metres from the bands. A 10 piece string ensemble peaked at 82 dbs. A 90 person big band with amplification of some instruments peaked at 108dbs. An unamplified solo drumkit peaked at 99dbs.

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RE: Is this acurate?

So the general concensus so far is that you don't need much more than about 30W? Good luck with that I say.

This may be suitable for dynamically compressed recordings, but not with wider dynamic ranges. It's the transient swings that are the problem.

A quick web search will tell you all you need to know about clipping.

 

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GSB
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RE: Is this acurate?

I always thought that as well as giving increased volume a higher rated amp would give you extra oomphh,for want of a better word. embarassed

Thanks for your replies folks,most enlightening beauty, eh

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RE: Is this acurate?

Overdose wrote:

So the general concensus so far is that you don't need much more than about 30W? Good luck with that I say.

This may be suitable for dynamically compressed recordings, but not with wider dynamic ranges. It's the transient swings that are the problem.

A quick web search will tell you all you need to know about clipping.

 

It really depends on the speakers, how easy they are to drive and senstivity. I think most people would be supprised how little power they use, and probably put the lack of 'oomph' with lower powered amps down to the lack of power, whereas its more likely the lower powered amps are cheaper designs with insufficient heatsinking, power supplys etc.

 

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RE: Is this acurate?

I'm very technologically challenged but I would hazard a guess that the figures given are largely accurate.

However, I think it's difficult to state categorically whether a higher or lower power rating leads to better sound. My Accuphase E-560 only puts out 30 W per channel in Class A but the sound is easily smoother and more powerful than the amp it replaced, which was a Jeff Rowland Continuum 500, rated at 500 Wpc.

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RE: Is this acurate?

lindsayt wrote:

At a recent music festival I was sitting 5 to 7 metres from the bands. A 10 piece string ensemble peaked at 82 dbs. A 90 person big band with amplification of some instruments peaked at 108dbs. An unamplified solo drumkit peaked at 99dbs.

 

OOI do you get any funny looks at a music festival when you're taking measurements with an SPL meter?

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RE: Is this acurate?

MajorFubar wrote:

I've said this for years.  And on this forum, too, before now.

I've got a 25W Cyrus One knocking around here unused.  It was my main amp when I bought my Mission 794s two years ago, and in my 15'x12' room it'll easily make my ears bleed before it even thinks about clipping or running out of gas.

All the guys who say that's not enough, wow I'd love to know what levels they listen music at.  Or what concert-halls they live in.  Or do they just have insensitive speakers. Or maybe they're just plain mutton-jeff.

At what I call comfortable listening levels in my room with my speakers, I really don't think any amp would be pushing out more than 5-8W RMS p/c at the very most.

Amplifier power requirements are directly related to speaker efficiency. Inefficient speakers require lots of power and I speak from experience. My Magneplanar MG12's sounded anemic  and lifeless when I drove them with a Unison Research Unico rated at 80watts per channel. Next up was a Cambridge 840A rated at 120 watts per channel which did bring about some improvements but still lacked in bass power and drive. I finally settled on a Plinius 9200 rated at 200 watts per channel and this really brought these speaker to life. Deeper and tighter bass, better dynamics and a sweeter top end. So yes, amplifier power is directly dependant on the speakers you choose. You simply cannot drive inefficient speakers to realistic levels with a low powered amp.

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RE: Is this acurate?

Bear in mind (and my experience with the Maggies) that as they are a 4ohm load, its might not actually be the overall voltage from a high power amplifier but its ability to deliver that power and current at lower impedance in a stable manner.

It just so happened that the best amplifier I used was also the best specified power supply. I went from an Audion KT88 amp (8ohm tap) to Quad Elite to Restek Challenger, the latter having a massive power supply and doing a lot better (more stable) into low impedance loads than the others. It also made no noticable difference in overall SPL ability (going from 15wpc to 200wpc) but was a lot better in the bass.

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RE: Is this acurate?

Well I had a demo with Rega CD Rega Brio R amp and B&W CM1 speakers which are 84db, there was some background noise room was fairly large, had to have the violume at 11 oclock to hear it, if I turned the volume up to 12 it sounded harsh and unpleasant, so that is clipping as far as I know and that is with cd which is high output, if you use turntable or tape as your source you will need to turn the volume up a lot more for same volume as cd. It is not the contineous noise level but its when someone hits the drums etc., Anyway the Rega I felt was strained and struggling and that is 50W I believe, 70 should be OK depends on room and speakers.

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RE: Is this acurate?

For what its worth, I've listened to 250 watt power amps from Gryphon and Hegel and then listened to my amplifier which is rated at 45 watts (but you can think of it like an 80 watt ss amp). My amp is quite powerful and it goes pretty loud. With the Gryphon and Hegel you listen louder without noticing it because the amps are under no stress at all. The amazing thing is that with such amplifiers you can still talk without raising your voice at above normal listening levels. My room isn't huge either its 18*15. The Gryphon and Hegel just sound more effortless at highervolume levels than the Cayin and not to mention the fact that the performance is a lot more dynamic as these amps have more power in reserve. So yes, a small amp might have enough power but doesn't have the sense of effortlessness as a big amp nor the same ability to convey musical peaks and are usually better at complex music. 

 

 

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