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Trevor Wilson[_3_] Trevor Wilson[_3_] is offline
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Default Attenuate highest highs?

On 20/02/2020 11:05 am, ~misfit~ wrote:
On 20/02/2020 10:44 am, Trevor Wilson wrote:
On 19/02/2020 1:02 pm, ~misfit~ wrote:
On 19/02/2020 11:14 am, Trevor Wilson wrote:
On 19/02/2020 6:41 am, Trevor Wilson wrote:


**Those "tinkling noises" you hear are somewhere around 3kHz.

**Should read: "....somewhere around 3 ~ 5kHz."

It seems to be higher.


**Until it has been measured, then we're both guessing. Few
instruments go as high as 5kHz. There is almost nothing beyond 10kHz
in any music.


FWIW I just did this on-line frequency hearing test:
http://onlinetonegenerator.com/hearingtest.html
and through my monitor-mounted Dell soundbar (with 25mm drivers) I
could hear to just over 12.5kHz but through the stereo in question
could only hear to about 11.5kHz. That's quite a bit lower than the
last time I used a similar tool a few years back. Maybe those years
when I spent hours several nights a week at a mixing desk at live
(loud) gigs in my 20s are coming back to bite me?

So now I'm a bit baffled. The issue I have is due to sounds at the
highest frequencies that I can hear and that seems to be ~11kHz with
this system in the current configuration. Maybe they have a peak
about there or are flatter than the other speakers I've tried...


**Until you perform some measurements, you're guessing. You could try
to acquire a (preferably digital) parametric equaliser and perform
some measurements.

I still betcha room treatments will solve your problems. IME (which is
substantial), room treatments solve most mid-HF problems, PROVIDED
there is nothing inherently wrong with the equipment, or the amp is
not being clipped.


Very few instruments possess fundamentals that reach 5kHz. A very
tiny number posses harmonics of significant levels that exceed 10kHz.

Turn the volume down and see if the sound is still annoying. I
suspect you are clipping your amplifier. Clipping can generate large
amounts of high frequency harmonic content. And, just to shut down
any myths you may have heard: Valve amplifiers WILL clip and WILL
generate excessive high frequency harmonics if over-driven.

It's not clipping. The Dynaco ST120 I have hooked up at the moment is
a solid-state amp and I no longer own any valve amps.


**You've checked with a 'scope to ensure no clipping then? Or are you
guessing again? It might worth looking at the waveform on a 'scope to
see if there are no parasitics present.


Of course I'm guessing. I know this is rec.audio.high-end but I don't
have (or have access to) a parametric equaliser or an o'scope. When I
say I'm not listening at low 'office level' volumes I also don't mean
ear-bleeding party volumes. Maybe somewhere in the 'half volume' range
on a 60 - 80 wpc amp... I've currently got a Marantz Stereo Reciever
SR4023 hooked up set to 'flat' (it has a pre/power loop for the
subwoofer amp) and the issue is the same - but the amp belongs elsewhere.

However I have used these speakers with a few different amplifiers,
(from 25 watts /channel class A up to 160 w/c RMS) and at different
volumes and in different locations and the issue I perceive persists.

I realise that without measuring we're all making educated guesses.
Really I just wanted to know what to add to the speaker crossovers /
tweeter wires to attenuate frequencies above say 10kHz by maybe 3db (and
not attenuate the crucial frequencies where female vocals and the upper
reaches of electric guitar solos and harmonics reside).


**Without proper measurements, we are all still guessing. However,
should you wish to perform some experiments and spend a little money,
this product MAY solve some or all your problems:

https://www.behringer.com/Categories/Behringer/Signal-Processors/Equalizers/DEQ2496/p/P0146#googtrans(en|en)

Even at the retail price of around AUS$600.00, it delivers phenomenal
performance for the money.

Fortunately, the products are easy to find on the second hand market.
Prices tend to be quite low.


Here is one I found on eBay:

https://www.ebay.com/itm/Behringer-U...AAAOSwfOBeTBi8

To put that price into perspective, I recently sold an analogue
parametric EQ for AUS$500.00. For some reason, some people prefer the
old, far less powerful and far less flexible, analogue EQs. I've used
Behringer products many times and, while they're not perfect, they
generally deliver excellent performance for the money. A parametric EQ
is a very powerful tool. A digital parametric, like the Behringer, much
more so. You can zero in on a very narrow band of frequencies and notch
any problems out. Like all EQs, you can also misuse them.


--
Trevor Wilson
www.rageaudio.com.au