A Test. How much Voltage (power) do your speakers need? - Page 38 - diyAudio
Go Back   Home > Forums > Loudspeakers > Multi-Way

Multi-Way Conventional loudspeakers with crossovers

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
View Poll Results: I measured the test tone at:
2 volts or less 144 37.40%
Between 2-5 volts 130 33.77%
Between 5-10 volts 51 13.25%
Between 10-20 volts 24 6.23%
Over 20 volts. 36 9.35%
Voters: 385. You may not vote on this poll

Reply
 
Thread Tools Search this Thread
Old 5th February 2012, 05:32 AM   #371
Pano is offline Pano  United States
diyAudio Moderator
 
Pano's Avatar
 
Join Date: Oct 2004
Location: Milliways
Blog Entries: 4
Did what? Set a -18dB RMS pink noise signal to 85dB SPL?
  Reply With Quote
Old 5th February 2012, 09:54 AM   #372
AndrewT is online now AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Quote:
Originally Posted by Pano View Post
..............I will freely admit that I should have been more clear about using dynamic recordings in the first posts. My mistake. I will go back and edit that so as to be more clear...........
Not a mistake.
Simply that the test as proposed is flawed.
It does not predict how little power we need to avoid clipping when we play our systems at the loudest we want to hear at.
__________________
regards Andrew T.
  Reply With Quote
Old 5th February 2012, 11:17 AM   #373
diyAudio Member
 
JRKO's Avatar
 
Join Date: Dec 2003
Location: U.K.
Send a message via AIM to JRKO
Unless Pano was planning on publishing a White Paper, can he simply add a rider and be done with it
__________________
In the interests of full disclosure JRKO = James Rupert Kingsley Osborne. And yes, my parents will pay for it when I choose their retirement home
  Reply With Quote
Old 5th February 2012, 01:22 PM   #374
Pano is offline Pano  United States
diyAudio Moderator
 
Pano's Avatar
 
Join Date: Oct 2004
Location: Milliways
Blog Entries: 4
Quote:
Originally Posted by AndrewT View Post
Simply that the test as proposed is flawed.
It does not predict how little power we need to avoid clipping when we play our systems at the loudest we want to hear at.
Andrew, this is so completely wrong that I'm surprised at you.
What don't you understand about the test? All your concerns have been met and explained by me and by others.

Until you can demonstrate, point by point, how the test is flawed, I must consider your responses irreverent.
  Reply With Quote
Old 5th February 2012, 02:09 PM   #375
Pano is offline Pano  United States
diyAudio Moderator
 
Pano's Avatar
 
Join Date: Oct 2004
Location: Milliways
Blog Entries: 4
For those of you who own an SPL meter - or want to buy one - here is some pink noise for you. It is recorded at -18dBFS RMS. There are two files. One is mono, the other stereo. In the stereo file, left and right are uncorrelated, I.E. they are random compared to each other. Each is 11 seconds long.

I suggest playing them in loop, one after the other. Move your SPL meter around the listening area and look for an average 85dB reading. Your meter should be set to Slow and C weighting.

This will set your system to the SMPTE PR-200 standard level. The EBU uses the same level. Movie soundtracks are supposed to be mastered at this level. This should give you 18dB of headroom over the average level. or peaks of 103dB, if your amp and speakers can do it.

I think you will find that this is much too loud for normal CD listening, as many CDs are mastered much hotter than this. The peaks won't be higher, they are still at 0dB on the recording, or 103dB SPL at your chair. It's the average level of most CDs that will be higher. But that's OK, it may be close to your "As Loud as I Ever Want to Go" setting found by ear. I doubt you'll ever run louder than this, but please tell us if you do.
Attached Files
File Type: zip Pink mono minus 18dB.zip (127.9 KB, 45 views)
File Type: zip Pink stereo minus 18dB.zip (258.0 KB, 47 views)
  Reply With Quote
Old 5th February 2012, 04:54 PM   #376
Pano is offline Pano  United States
diyAudio Moderator
 
Pano's Avatar
 
Join Date: Oct 2004
Location: Milliways
Blog Entries: 4
FWIW, I just tried the above test of setting my system level at 85dB. It came up right at 12:00 on the volume knob. Surprise, surprise. 12:00 was my by ear "plenty loud enough" setting.
I do find it much too loud for most listening. Checking at an enjoyable listening level I find the input signal is 8-12dB lower on average.
  Reply With Quote
Old 5th February 2012, 05:18 PM   #377
GM is offline GM  United States
diyAudio Member
 
GM's Avatar
 
Join Date: Jun 2003
Location: Chamblee, Ga.
Quote:
Originally Posted by 5th element View Post
Thanks for your response GM this is actually a very good example of what this test isn't about and can hopefully serve as a good example for those who perhaps don't quite get it.........
You're welcome! Thanks for the thread summary, I donít have time these days to do more than a quick scan of long threads.

The test does seem a reasonable alternative to the time honored SPL measurement way to determine a 70V distributed systemís power requirements in todayís digital Ďworldí, but it's what it claims to do that concerns me, i.e. provide the information required for someone to determine how much power they need Ďworst caseí if they don't want to clip the amp with whatever digital sources they currently have on hand [or may buy in the future, not to mention some analog recordings] plus I see no way to use it for setting up a proper HT and/or multi-channel music system, so donít want folks to be mislead into believing this procedure will necessarily do what is being claimed.

I mean how does one know how much their existing amp and/or speakers is probably clipping doing this test unless itís already sufficiently oversized, especially if itís a tube amp and/or ĎFRí driver? Or how dynamic the signal?

Folks tend to set max levels based on audible distortion, so any conclusion seems predicated on a test that may be ill suited for the app since the more dynamic it is, the more itís likely to be clipped, so it may be just less clipped with the calculated power available unless the normal average is somewhat, to well, below the test setting.

Worse, the most dynamic CDs I have donít have the most power hungry spikes in its loudest passages, so how is some arbitrarily chosen 120 or 220 Hz test tone going to account for these spikes?

Indeed, the only way I can [or at least once, could] hear them was by noticing more top end Ďairí around the instruments after seeing the spikes using an SLM, i.e. one step closer to what Iíve experienced in concert halls, piano bars, etc., so how likely is one to notice such subtlety using this test unless their amp, speaker system was already grossly oversized [at least by the tone of this thread] and know what to listen for?

105 dB peak/channel at the Lp is a goal for those folks that want to reproduce movie soundtracks at DD/THX/DTS reference. This is based on an 85 dB average at the LP. Since the gain is fixed at 20 dB for the mains and 30 dB for the LFE channel, itís scaleable to whatever average or peak one desires.

If not sitting up close, it also happens to be in the ballpark for the piano bars, jazz clubs, small concert venues or similar I once frequented before mind numbing Ďloudí at the expense of SQ became a prerequisite, so has been my personal reference level for long before these standards were proposed, though of course the dynamics of live venues are somewhat higher than all but a precious few recordings Iíve owned/auditioned.

Not that I havenít enjoyed some of the loudest concerts on record to the point of ~mimicking them at home with the required highly efficient, high powered sound system required that might not have been adequate based on my understanding of this test if done today. As TD noted:

ďHow much Voltage does it take to reproduce the variety of things I like to listen to in their dynamic entirety?

The answer to me seems that it depends on the dynamic peak to average ratio in the music and the dynamic nonlinearity of the speakers and not just 4X the .5VRms margin.
That margin IS plenty for a lot of recordings, especially modern pop but well short of others, way short of reproducing real life events in a normal noise floor.Ē

All that said, if itís a high output impedance tube amp, Iím ambivalent about clipping the really fast transients as the ampís harmonic distortion is normally perceived as adding top end Ďairí regardless, so this test should be adequate for finding its reasonably low distortion power minimum or conversely, the speakerís efficiency to meet a specific average SPL.

GM
__________________
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
  Reply With Quote
Old 5th February 2012, 05:28 PM   #378
Pano is offline Pano  United States
diyAudio Moderator
 
Pano's Avatar
 
Join Date: Oct 2004
Location: Milliways
Blog Entries: 4
Sorry GM, you simply don't understand the test. All the issues you mention above have been covered. I've tried to explain it, but it seems to be out of my reach to do so.
It's super simple and easy to do.

The ONLY variable is where you set your volume control. I've asked for folks to do that using dynamic recordings and have now even supplied pink noise for an 85dB reference.
I just don't know how much simpler I can make it.

I'll go over your points 1 by 1 in a few minutes.
  Reply With Quote
Old 5th February 2012, 06:00 PM   #379
kevinkr is offline kevinkr  United States
diyAudio Moderator
 
kevinkr's Avatar
 
Join Date: Sep 2004
Location: Boston, Massachusetts
Blog Entries: 6
Several off topic and personal posts have been deleted. Please let's focus on the discussion and not each other.. Thanks..
__________________
"Extraordinary claims require extraordinary evidence." - Carl Sagan
  Reply With Quote
Old 5th February 2012, 06:06 PM   #380
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
Test is done, apologies for the rotten pics... it was so bleedin' loud ya know

And that's with a fresh set of earplugs well fitted lol

So I did the test, you can see the SPL meter here, C weighted. Very little difference between the mono and stereo tracks.

I then went back and ran Panos 220 Hz track at this same volume setting and measured 3.7 volts RMS.

Keeping that volume setting I played the Eroica track that I posted "Cooledit" shots of earlier. That peaked at around 93 ish db. And it was to loud for comfortable listening for me at that.

The Mooly Amp has power meters accurately calibrated in volts onto 8 ohms and so I guestimate the Pano noise test at 0.5 w RMS. Clear shot of the meters so you can see the scale.
Attached Images
File Type: jpg Test 1.jpg (242.1 KB, 236 views)
File Type: jpg Test 2.jpg (251.7 KB, 225 views)
File Type: jpg Test 4 Meter.jpg (233.3 KB, 220 views)
File Type: jpg Test 3.jpg (250.5 KB, 215 views)
__________________
-------------------------------------------------------
Installing and using LTspice. From beginner to advanced.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
LM3875 power up test.. and it crackles w/o speakers attached? Keyoke Chip Amps 9 2nd March 2012 01:39 AM
how to test chokes for current and voltage speakerfritz Tubes / Valves 10 20th October 2010 11:32 AM
Aleph 30 problem - half of power supply voltage on speakers output yoke Pass Labs 18 15th March 2009 05:18 PM
How to test speakers? zaydenam Multi-Way 2 27th August 2008 01:02 PM
Test speakers? Ryssen Multi-Way 3 2nd March 2004 10:54 PM


New To Site? Need Help?

All times are GMT. The time now is 08:13 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2