Power needs of Heritage series speakers

[mkane]

2a3 SET/Cornwall !'s here. Also have a 25wpp amp that just sit's. No soul.

[tube fanatic]

2a3 SET/Cornwall !'s here. Also have a 25wpp amp that just sit's. No soul.

How loudly do you listen, and how far from the speakers do you sit when listening?  I'm just curious about how much power you are actually asking those 2A3s to deliver.

 

Maynard

[mkane]

12' feet away from the speakers. Moderate listening levels.  Pic's taken just behind the hot seat.

 

 

Edited August 8, 2015 by mkane

[garyrc]

12' feet away from the speakers. Moderate listening levels.  Pic's taken just behind the hot seat.

 

Your room looks great!

 

What is the L, W, H of the room?  The ceiling looks pretty high.  One way to think of it is "How far from the speakers?" ... another way, is "What is the room volume in cu. ft.?"  Klipsch once created an amplifier power rating table that, I believe, is reproduced at the beginning of this thread.  This table is based on 3,000 cu. ft., R = 200.  According to it, out in the room (not at the potentially misleading1 meter!) 18 watts into a single Cornwall would produce 105 dB, with some room left over for peaks above that.  A usual safety factor allowance for peaks would be 3 dB, bringing the SPL to 108 dB.  Historically, people would say that would be 111 dB for peaks if two speaker systems were in use, as in 2 channel stereo, but I've never been comfortable with that because it banks on equal power needs for each of the two channels, but if there is a very loud set of instruments at one time, on one side (timpani, great gong, bass drum and piano all on one side in the fff finale of the Great Gate of Kiev) there may be clipping.  PWK thought that, for peaks, there should be 115 dB available at your ears, but he was using the "equal power needs assumption" for a three channel system.

 

Your room looks fairly live, and you say you listen at moderate levels, so you might be O.K. with lower effective SPL than I would want in my deader room, with big orchestral climaxes.  Your distance of 12 feet seems reasonable.  PWK once ran a test at 16 feet, calling it "normal listening distance."  In recent years I believe people have tended to move closer, except with the larger home theaters.

Edited August 8, 2015 by garyrc

[mkane]

Rooms 17x26. The ceilings 25' tall for the the first 3rd of the room, 9' for the rest. I put up 1st reflection sound panels for critical listening sessions. It's a difficult room to get better sound. When I want to go loud there's a  pp EL34  amp that we can use. That's not often.

 

 

 

[garyrc]

Wow! If you routinely listen at over 90db you will enjoy this hobby for maybe a half dozen years. Then you might as well sell everything (I call dibs on any cool vintage tube gear) and buy a boom box because your hearing will be shot.

http://www.dangerousdecibels.org/education/information-center/faq/

 

 

Several charts of maximum tolerable SPL look like they are the result of "dry labing."  Any safe SPL chart -- for music -- would have to include 1) length of exposure 2) peak v.s. average (e.g. Heavy Metal or Rock tends to be louder, more or less continuously, for longer periods of time than Classical, Romantic Period, or Modern Orchestral.  In fact, the average level of Heavy Metal / Rock, live and close, resembles the most common, very, very brief peaks in orchestral music, maybe 100 to 115 dB for both examples).

 

The linc above fails in this regard , except for citing very few durations, and pointing out that certain sounds are so loud, e.g., nearby gunfire, that a very brief exposure can cause hearing loss.

 

Last time I looked at OSHA standards, they caution that 115 dB for just under 15 minutes straight, within the (narrow) dynamic range of their specified signal, was the upper limit.  That never happens in orchestral music, but could happen on stage in an amplified band (or close to the stage).  That's why band members wear earplugs.

 

I have been an audiophile for many decades and have been in several orchestras, and my hearing is fine.  Same for friends with similar experiences.

 

EDIT:  It is important to not go by just any website.  I just checked the OSHA website again, and found the following info:

 

1) As of January 1, 2015, employers must notify OSHA if workers are exposed to "noise" above the A weighted (does not count bass as much as either C weighted or Flat), "slow" (closer to average than peak), readings for the durations specified in the table OSHA supplies. 

 

2) If the SPL is more than 85 dB, for an 8 hour work shift, the employer must implement a Hearing Conservation Program. 

 

3) Here are some excerpts from OSHA's table: 

• 115 dB. A weighted, Slow, is permissible for 15 minutes or less
• 100 dB, A weighted, Slow, is permissible for 2 Hrs
•  92 dB, A weighted, Slow is permissible for 6 Hrs

They also note that impulsive sounds must be below 140 dB, Peak (since they are citing a peak level in this one instance, unlike in the others above, I'd guess that they want the SPL meter set on "Fast" this one time).

 

Nothing like the SPLs/durations above happen in orchestral music.

 

Now, I'm certainly not urging tempting fate, and I'd imagine that the cilia can occasionally break even if not being exposed to loud sound -- or any sound, except for the sound of bodily fluids circulating.   

Edited August 9, 2015 by garyrc