dbx 1231 EQ acquired

[♔Chello]

dbx 1231 EQ acquired

I use a separate system for my subwoofer that has 2 built-in power amplifiers - one connected to 6 pcs 8" woofers in PUSH connection, the other connected to 6 pcs 8" woofers in PULL connection.
So 12 pcs 8" woofers, plus a 10" slave unit at the bottom.

A preamplifier is connected to the main preamplifier, and the dbx 1231 EQ is connected to this and finally to the subwoofer.

The purpose of this connection is to be able to provide different separate EQ to the PUSH and PULL units (own invention) - I use the dbx as a "stepless crossover", which allows for precise adjustment of the subwoofer.

I have used a dbx 231 which is a cheaper version, and the new one has much larger slide potentiometers, which makes adjustments easier - everything is of a far better quality.
dbx 1231 is widely accepted as a solid, dependable choice in professional audio environments.

I imported it from China, and paid only 250 US Dollars, compared to 600 US Dollars from a Norwegian dealer.
And this is not a clone, but a genuine item with accompanying registration papers and a serial number for submission to dbx, which confirms what is on the device.

It was sent by UPS, but they made many mistakes along the way:
I was told it would arrive on 09.04., but on the same day I received another message about the changed date to 14.04.
However, it arrived on 15.04, without any notification.
And then it arrived with Norwegian Bring - UPS had handed it over to them, while the norm is that UPS first requires payment of customs duties, and then delivers the goods to the door.


   

   

   

[♔Chello]

TEST SETUP - EQ CONFIGURATION

I have now positioned the dbx 1231 on the table in front of me in the listening position.

The distance to the subwoofer is ideal in terms of phase, so it can be in a neutral position on both power amplifiers.
I have deactivated all filters in the power amplifiers.

The dbx is, as is well known, graphic, and has fixed center frequencies, which is perfectly fine for my use.

I only boost the frequencies 20, 25, 31.5, 40, 50, 63 and 80Hz, while everything above is adjusted down to -15dB if necessary.

This means that it is possible to achieve a boost of 30dB in the bass range, which results in realistic levels in the sub range - if the power amplifiers can handle it, and mine do.

Most speaker systems have a sharp drop in sound pressure from 37 Hz and below of 20 to 30dB, and a separate EQ that only affects the subwoofer's power amplifiers is the best solution, because a global EQ also affects the main speakers, which is not desirable, as this destroys the working conditions of the main power amplifier and the speakers.

I only regulate the range from 80Hz and below, because this makes it impossible to position the subwoofer's position.
Most also regulate 100Hz, but this means that the position becomes detectable, which is not desirable.

I have no problems with standing waves (100Hz produces a standing wave sound), and prefer to leave this untouched.

The setup I use for testing is the only way to do this and achieve a guaranteed result - otherwise I would have had the help of someone to make the adjustments while I was listening.

[♔Chello]

TEST SUCCESSFUL

With all filters deactivated, the sound was terrible.

When I activated all filters, the sound was still terrible, with an opulent, resonant bass.

Before the test, I had read a technical test of the dbx, and it stated that the bass range was prone to phase reversal, which is unusual.

When I reversed the phase on the power amplifiers, the bass became normal again, and when I adjusted all frequencies from 20Hz to 80Hz up by +15dB and all above 80Hz down by -15dB, the sound was better than ever.


A correctly set up subwoofer should only say something in the lowest frequency range, and mine is like this - I can play regular music that does not have sub-bass without the sound image being colored, but when there is sub-bass, it is heard very clearly.

It is absolutely impossible to tell where it is located - the bass is felt everywhere, and extremely low frequencies below 20Hz are definitely present - you feel the pressure waves against your body like a physical blow.

Also, I hear details in the sub-range of music I know very well that I have never heard before.

So I am very happy with the result, and can move the dbx from the table to the rack under the keyboards.

[✪welsh wizard]

Your are a very brilliant man , there is no way I could do what you do with speaker technology etc ,etc ,its so amazing the information you tell us . I am baffled as to ..Why don't big manufactures listen and talk to you and people like you to progress and enhance music and music technology.

[♔Chello]

Your are a very brilliant man , there is no way I could do what you do with speaker technology etc ,etc ,its so amazing  the information you tell us . I am baffled as to ..Why don't big manufactures listen and talk to you and people like you to progress and enhance  music and music technology.

✪welsh wizard

Thank you for your kind words.



HiFi has been one of my main interests since I was a boy, and I have done many experiments with sound over the years.
I have always been critical of theories and the tendency to absolute interpretation of these - I insist on testing everything myself.

There are countless theories in the subject, and many of them require extensive mathematical knowledge, but everything can be learned.

People like me always meet with great resistance from "the learned", because we mess with their theories.

I would have liked to have had my own trademark and taken out patents on inventions, but here in Norway this is almost impossible to do, because large companies and the State at an early stage try to take over the invention by offering the developer a ridiculous sum and taking over all rights.


Most people have one or more areas in which they excel, but only a few put any special energy into developing their own abilities.