How loud is too loud

Fletcher-Munson effect! Human hearing has reduced sensitivity to low and high frequency sounds as volume is reduced! Older receivers and integrated amps had a switch to compensate for this by boosting the bass and treble. This allowed quiet listening to sound more natural! Same thing can be done with tone controls/equalizer. Nothing wrong with your system!

The switch was labeled "Loudness"!

I appreciate that my ears may not be as receptive to sound clarity immediately after turning the volume down after listening to loud music but the loss of sound quality is apparent for days after. I have been testing it with electronic dance music, starting off at low volumes building up to -30db, it starts off ok but then it is as if certain frequencies trip the system and I loose depth and loudness in the sound??

Great question;

There are cell apps that record DB for you.

I have a audio group & they all play at different levels.

My ears like softer

When reading & listening -60-65 dB
When really listening - 75-80 dB

One buddy -90-94 dB 

most others -80-85db

yes, I’m geeky

you may have damaged the tweeters 

Nothing wrong with a bit of geekiness frozentundra! However, what you suggest is a subjective thing about personal listening levels. This is a definite change from one day to the next in loudness at every level, so when the system is running properly everything is fine, when the fault occurs everything sounds about 10db quieter and almost tinny in the top end. 
I was hoping it was something like damaged tweeters, but I have been unable to replicate the fault at the shop I bought it from when I took it back for them to check out. it seems to be something that occurs after playing 'loud' music?

tcapone,

If the loss of sound quality is still there at loud levels, you blew a driver. if not, you are suddenly self aware of your ear's limitations.

Tuning speakers with a smile like curve helps them sound better at low volumes. Loudness controls in older preamps / receivers was also a great benefit.

Best,

E

Thanks for all your insight. 

I will carry on with some sound tests and see how I get on. The shop I bought it from have said they will come out and listen to it, so hopefully they can confirm. If not then maybe I really have damaged my ear drums in some way.

To be continued......

Maybe you damaged your hearing...

Another vote for the over-looked RS sound level meter.
I too use mine seemingly all the time.
Typical listening: 75 dB peaks (95% of all listening)
Rockin': 85 dB peaks (when I'm gettin jiggy with it)
Brief Moments of Euphoria: 95 dB peaks (very rare)

Damaged tweeter(s)- as a minimum the ferrofluid probably dried up - possibly voice coil is now rubbing and only works at all at higher volume.

In my experience, if/when the sound quality appears deteriorated after playing the music real real loud, either the tweeters or the listener’s ears, or both are damaged.

Just a little addendum to roberjerman's explanation. "Loudness" switch was pretty much ubiquitous on 1970s-1980s amplifiers/receivers. However, these days Luxman and Accuphase still include "Loudness" on, at least, their integrated amplifiers. It works.

80 dB, but often lower. 

Here's a calibrated microphone. You need to grab the calibration file online and move it to your phone, and not every app will use it. Audio Tools does.

https://amzn.to/2JutQI5

Best,

E

More listening today at normal listening levels. First album was Rene Marie-Vertigo, a calm vocal jazz album, played at low volume to warm the system - no apparent lack of sound quality. After 2 hours of playing at barely audible level I put on a techno album at an average listening level. It definitely sounded as if the tweeters were failing. There wasn't any distortion but they just sounded flat, weak and rubbish! Next challenge will be getting the shop I bought them from to agree !

There are frequency sweep apps available that may be helpful. Run the sweep via your phone, or computer, connected to your system. You will be able to hear the sweep frequency as it progresses from 20 db up to 20K db. Unfortunately, your hearing may drop off above 10K. If so, you might need a db meter to test for high frequencies. Or use a younger kid who still has good hearing.....

Thanks reubent. Will try and investigate.

What?

erik_squires,

I wonder if current batch of Yamaha integrateds (501, 701) has something similar to what you are describing Denon as. A friend of mine has one and it does exactly that, it gets quieter when you engage "loudness" which is actually not a usual old-fashioned button, but a knob with a certain range. It has not worked really well for me so far, to say the least, but I could not believe some fine engineers would put it there if it did not work at all. Next time, I will try making it louder and then using loudness the way you mentioned although, I admit, it seems a bit counterintuitive to me. We will see, I mean...hear.

erik_squires,

I was curious so I just looked at the owner's manual for Yamaha 301/501/701 on their website to see what they say about it. From your previous post, I got the idea that, after setting volume somewhere relatively high, engaging "loudness" decreases volume while somehow increasing (or relatively not decreasing) middle range.

However, they say "Enjoy natural sound even at low volume by lowering the mid-range sound level and compensating for human ears' loss of sensitivity to high- and low- frequency ranges at low volume."

If I am getting it all right, your description would be opposite from theirs although, at least to me, yours seems more logical. Not that I have any deeper knowledge of these things. What do you think?

Also, their explanation leaves room for more explanation, but they left it for some other owner's manual, I guess.

https://usa.yamaha.com/files/download/other_assets/8/332208/A-S701_S501_S301_om_U.pdf