Re: 80dB now but still needs improvement at 1KHz

On a sunny day (Thu, 7 Nov 2024 08:40:02 +0000) it happened
liz@poppyrecords.invalid.invalid (Liz Tuddenham) wrote in
<1r2n91y.4mv6llmpj328N%liz@poppyrecords.invalid.invalid>:

Jan Panteltje <alien@comet.invalid> wrote:
>
[...]

Speakers and room acoustics...
I have some, everything is different, should be.
I liked the Quad electrostats,

>
You needed a lot of space and good room acoustics to get the best out of
them.
>

just have some chaep bass-reflex boxes now.

>
Bass-reflex looks good on paper but sounds horrible.  The human ear
hears the 6dB/octave roll off as 'natural' but with an unnatural 'honk'
superimpose on it.  Bass transients are coloured by the honk and give
hang-over effects.
>
It may not matter for synthetic pop music, but bass-reflex speakers can
give misleading results if they are used for monitoring acoustic music
recordings.

Yes, OTOH the sound is a lot better than what came out of the TV speakers :-)
The boxes have some piezos for high frequency too:
 https://images.marktplaats.com/api/v1/listing-mp-p/images/34/34ab31bf-bc98-44d0-a210-b8ea75e074dd?rule=ecg_mp_eps$_83
  now > 20 years old..

Was cheap,
also have a Mc Crypt power amp to drive it:
 https://asset.conrad.com/media10/add/160267/c1/-/gl/000302573ML02/manual-302573-mc-crypt-xpa-225.pdf
2 x 100W sine into 8 Ohm
 Used it for all sort of things,

And this one of course:
 https://panteltje.nl/panteltje/amplifier/index.html
  nice chip, been on about 12 hours a day since year 2000?

So, as you can see, I am no audiophile...
That last amp also drives my cryo-cooler with 60 Hz in mechanocal resonance via a reverse connected main transformer for 50 Hz (for a.o. anti-graffity experiments>_
 https://panteltje.nl/pub/cryo/

or maybe if you need cooling for an ultra-low-noise amp?
or just to make some rocket fuel..

I just found this:
 https://panteltje.nl/pub/audio_90_degrees_phase_shifter_top_IMG_6903.JPG
 https://panteltje.nl/pub/audio_90_degrees_phase_shifter_bottom_IMG_6904.JPG
 https://panteltje.nl/pub/audio_90_degrees_phase_shifter_circuit_diagram_IMG_6958.JPG
 https://panteltje.nl/pub/audio_90_degrees_phase_shifter_PCB_top_view_IMG_6962.JPG
 https://panteltje.nl/pub/audio_90_degrees_phase_shifter_PCB_bottom_view_IMG_6960.JPG
Thst is a 90 degrees phase shifter over the speech audio range for generating I and Q signals for SSB modulation.
 design is not mine, used trimpots to test it :-)
One of many experiments...