using the Radio shack SPL meter

Jaffeassc
thanks... I don't think the max thingy was in use.

Shadorne
db? I meant %. I may have misheard the reading of the info too, though I really thought the manual said +/- 10% accuracy.... at what range (if any was specified) I don't recall. the concern was that 10%. 10% of a 90db reading is 9db. that is pretty big if you ask me.

Montytx
Thanks. I tend to agree. the issue for me is I have no previous refference. Any reading came as a suprize to me. though I felt the 91-92 (fast) readings preety fair an assessment... yet again... had no previous ref.

What I find amazing, or better yet, most interesting, about the SPL readings of ambient noise/sound at the LP, is the type or fashion of the sound being realized at the ears. Volume was surely in abundance, yet the striking, impacting or visceral dynamics were still not agregious.

The best I can describe it is the diffs from a plannar speaker to one using cones. these were cones too, though with limited responnse pressure levels... agan, 85db or so.

At no time was the sound near approaching "piercing".

Other speakers I've owned with greater Eff #s have had that "piercing" trait however. So there is IMO more to SPL than simply SPL. In fact I could well stand a touch more of a striking quality, but only just, to add to the dimensionality of the sound as well. The "jump" factor as I call it was lacking.

"A dollup or two more jump, if you please, my good man."... and I am a happy camper.

Swampwalker
i know what you mean. it is suprizing, huh?

Makes me really wonder about speakers PROFESSING OR providing 100+db SPLs.

Who can handle that? Unless only a watt or two is used.

OK, So is there a better, or easier way using a PC to gain greater accuracy, and ease, in redeeming acoustic numbers, like SPL, nodes, nulls, spikes, etc?

....without a big expense being necessary?

Using the Windows XP Pro PC & monitor would be a very good thing for me. I'd not need any assistance.

Makes me really wonder about speakers PROFESSING OR providing 100+db SPLs.

Who can handle that? Unless only a watt or two is used.

Jim,

My speakers "profess" to handle up to around 115 db SPL average continuous level with head room of around 10 db at 1 meter. This is with distortion levels extremely low (around 1% or so) and only modest compression.

Of course I never listen this loud.

At 2.5 meters back I sometimes listen up to about 105 - 108 db SPL (AVERAGE level - confirmed with Radioshack Meter) which is equivalent to attending a rock concert. This is loud.

However, to put things in perspective, at the hockey game last night the SPL meter in the crowd showed 115 db SPL - yet nobody was covering their ears and complaining that this was piercingly loud.

What actually sounds piercing and awful to the ears is DISTORTION - even at modest SPL levels!

Modest amounts of distortion will sound terribly loud at 90 db SPL (distortion levels are inherently linked to perceived "piercing" loudness)

What you might have experienced was increasing distortion at high SPL's (for your system) making it sound extremely loud when you only had a maximum of 91 db SPL at the listening position.

10% of a 90db reading is 9db. that is pretty big if you ask me.

No.

If the accuracy is +/-10% then this is equivalent to +/- 1 db SPL at 90 db SPL.

Decibels are a logarithmic representation of a signal.
SPL = 20 Log (Actual Signal Reading/Reference Signal Reading)

Reference signal level was set by Bell Labs as the quietest sound the average person can detect at 1 Khz (defines 0 db SPL)

Jim,

Here is an example.

Take a classic famous well respected "hall of fame" type speaker like the Wilson Watt Puppy 7.

Look at the two distortion plots at 90 db SPL and at 95 db SPL (top curve is output SPL and bottom curve is THD+N SPL)

Notice that as the sound level is raised by 5 db SPL the distortion components increase by much more (8 or 9 db SPL)....this is always the case, even on great speakers such as this. The higher the output levels (towards realistic live sound) the relatively greater distortion ...until eventually the distortion becomes audible (and perceptively very loud). This point will vary for each system of amplifier and speaker but generally even small systems can be made to be perceived as sounding very loud (but in a small system it is mostly the harshness of distortion and not ACTUAL SPL level that gives the impression of loudness)

Shadorne

Gee thanks. My heads swimmin' now from all the input you've mustered here. ...and I was once a whiz at math. Thanks much.

The distortion aspect you put forth is likely on the beam. that system was simply put at best, sterile and analytical. Nothing by way of cabling, isoing, conditioning, decent front end . . . just some cheap CD player, a Krell amp and my rusty, dusty Sony receiver as preamp. All in a much smaller room too.

That sound is not one I have today, nor do I want any part of it again. A touch more jump perhaps, but that's about it.