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How can I establish a reference level?

With now 350+ hours on my new rear end (I hope it is OK to call the new speakers that, given the common use of the expression front end for the source) I am trying to understand gain and how it relates to listening level. The terms reference level, anchor level, gain structure, dB, dBU, crest factor, etc. all form an ill defined blur. My interest is in protecting one of my five senses. No amount of money and equipment swapping will ever reclaim lost hearing! Now with oodles of distortion free headroom I need to be careful.

Specifically -
JBL 4367 - 94 dB, 300W
Benchmark AHB2 in bridged mono 380W
SONY XA5400ES Compact Disc Player

What I find is -24 dB set on the preamp (with 0 dB being no voltage gain or cut with respect to the source signal) is too loud on most recordings - especially Pop and Jazz. On the 1964 SONY Classical recording of Petrushka, Ormandy (SBK 47664) a gain of -24 dB is pretty realistic as it is on many other classical recordings.
Some recordings sound loud no matter what the volume. Take Jimmy Smith with Kenny Burrell (Phono 870267) for example (listening to him now @ -34 dB)
Much of my listening is far-field, though the speakers are only about 6' apart in an open floor plan of about 1200 sq. feet.

The inverse square law relating to how loudness decreases with distance from the source - how is it affected by a stereo pair? Get on axis near-field with the speakers and just try and keep your mouth shut. Awesome!

So I have a new definition of LOUD and I want to be careful and have some consistency.
I feel -24 dB is a good reference level and am wondering how that relates live sound and the recording process.




mikewerner
mikewerner OP
119 posts
 

Yage- thank you for the link. I remember seeing that article awhile back and the reread was definitely worthwhile. To be clear, my room is small. The fatigue I speak of with levels 85dB+ has more to do with that than the equipment. Lots of room gain. I have done what I can to treat it but still, high levels are tiring. 

72dB is a good recommendation. Thank you for your response.

mikewerner OP
119 posts
 

UPDATE:

In my post on 4/30 I mentioned there was a Pass Labs XA-25 OTW.

Well, it's here and has been up and running for about 3 months.

If you have speakers that SUCK power forget it, but for the JBL 4367s the amp is great. Compared to the AHB2s the XA-25 draws you in. At times with the AHB2s I felt I needed to put up the yellow caution tape, "Do Not Approach." Not so with the XA-25. If I want louder, moving from mid to near-field does the trick. Near-field with the AHB2s is a bit much.

But for a party on the back porch I can open the windows and turn it way up with the Benchmarks. They are more convincing at loud levels.

kota1
2,706 posts
 

I'm glad you started this thread, sometimes the importance of ear drum preservation gets "lost in the mix". The problem is some music starts softly, peaks loudly, etc. But it is something that needs attention once I moved from a condo with neighbors to a private dwelling, no limits if you know what I mean.

mikewerner OP
119 posts
 

Update:

In house now is a ML No. 534. OMG!!!

This amp and speaker combo effortlessly produces the whole thing.

Like a tapestry.

Noticeable are the dynamics. Quiet and LOUD! 

The JBL 4367 and ML No. 534 play exceptionally well together.

mikewerner OP
119 posts
 

UPDATE:

Having not had any parties on my porch for some time, I have switched back to the XA-25 in front of the JBL 4367. I'm glad I did. The 94dB JBLs get as loud as I want with the XA-25 and sound absolutely fantastic. The higher powered amps, ML534 and Benchmark AHB2, seem to prefer higher volumes and this is tiring. On the JBL 4367 the XA-25 gives me fatigue free listening and sounds more like music at all volumes.

Noticeable are the mid-bass textures and overall glare-free presentation. Those 15" woofers are handled with aplomb by the XA-25. It is amazing that 25W will do it, but these are a very special 25W. To paraphrase Dick Olsher, if the first watt is no good who wants the rest?

 

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