High Efficiency Speaker Asylum Need speakers that can rock with just one watt? You found da place.

---

[ Follow Ups ] [ Post Followup ] Thread: [ Display  All  Email ] [ High Efficiency Speaker Asylum ]

---

[ Alert Moderator ]

---

RE: I have a problem ... i have a question on HE speakers but regarding amps to drive them

Posted by tomservo (M) on July 5, 2014 at 09:41:57

In Reply to: I have a problem ... i have a question on HE speakers but regarding amps to drive them posted by beppe61 on July 4, 2014 at 12:15:09:

Hi
Your question is easy from a hifi perspective but is not an easy one to answer in a technical sense as what we hear as “loudness” is rather separate from the issue of what is needed to reproduce a recording / signal.

What we hear as “loudness” is something like a short term average (like a VU meter shows) BUT the only real way to tell if you have enough “power” is to look at your amplifier output with an oscilloscope when playing music at the level you desire.

Everyone knows what “clipping” sounds like BUT very few realize if clipping is short enough, you can’t hear it as a “flaw”.
On the other hand, if one switches back and forth from an amplifier which is clipping on peaks vs one that isn’t, the difference is the un-clipped amp sounds more dynamic, more lifelike. Some don’t care about that, some do and this is not strongly connected to enjoyment.

Also, there is a huge variety of music and it’s requirements, some music has a peak to average level of 10dB or maybe less (like typical rock on an FM radio where the level meter is near stationary) or can be as much as 30 or 40 dB on quality recordings. 30dB means that the instantaneous peak levels requires 1000 times more power than the average level requires, 40dB means 10,000 times more power.

With a 95dB sensitivity, assuming a stereo where one has two independent channels / signals and 2 meter listening distance, one has a 1w sensitivity at the LP of 89dB. If one had a 10 W amplifier, then one can calculate that for compressed FM or pop music, a peak level of 99dB could be achieved while the average level would be 89dB (pretty loud sounding in a home).

On the other hand with a 40dB peak to average recording, then the peak level at clipping would be 99dB but the average level would be 59dB, not loud at all.

In the extreme, If you live in a quiet house, the background noise level may be low, say 10 to 30 dB and so if one has a recording that uses the entire 96dB dynamic range of a modern CD, that requires a peak level of 126dB at the LP and requires about 5000 Watts with no loudspeaker power compression.

Thankfully there are no recordings I know of that come close to using up all the dynamic range of the CD medium this same issue is why we have the “loudness wars” in the recording industry, if you listen to music in your car or jogging, the noise floor is VERY high and to hear the music, it must be above that level.

Dynamic Compression raises the average level and reduces the difference between the peaks and the average making it possible to reproduce it with limited power and spl that tiny speakers can produce.

The link below might be fun, it is a modern “VU” meter that shows average as well as peak levels, while this works on music at the file level,
looking at your amplifier output with an oscilloscope, playing the music you desire is the ONLY way to know if your amplifier / signal chain is producing the signal without instantaneous clipping / with the full dynamic range in the recording.

http://www.orban.com/meter/
Hope that helps.
Tom Danley
Danley Sound Labs

• Modern VU meter   (Open in New Window)

This post is made possible by the generous support of people like you and our sponsors:

VH Audio

---

[ Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2024, Audio Asylum, all rights reserved ]

---

[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]

---