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dbx 1231 Graphic EQ Review

respice finem

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Unfortunately only if you’re using a computer as a source. If you’re not your options are more limited. I use an RME ADI-2 DAC for headphone EQ since I don’t have a computer in my headphone chain, but I’d love it if someone made a dedicated digital-in/digital-out parametric EQ box with a lot of memory slots and more PEQ bands than the RME has.
While this exists, it will need a computer to operate...
 

JohnBooty

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I have the "little brother" EQ of this unit, and I really like it.

I like it because of the physical sliders. Not because I have some kind of fetish for these particular sliders -- they're a bit cheap feeling on mine, honestly, though they get the job done.

No, I like it better than digital because it's just so easy to dial in a little extra (or less) bass or treble depending on current needs. Are there other people in the house trying to sleep? Are my sinuses extra clogged that day? etc.

I wish there was a simple, MiniDSP-style digital EQ that gives physical access to some presets like that. I am imagining something like a MiniDSP with 5 "preset" buttons on top. Must be simple enough to use when drunk.

some people strongly believe that hardware has some "magic sound" that can't be reproduced with software... maybe it's the magic of noise, IDK...
It would be nice to do some tests of this, as much as it's possible anyway, in a controlled/scientific manner.
I've never seen that claim applied to analogue EQ, honestly!

Of course, it is the internet, and I'm sure we can find somebody claiming that. I see fans of analogue amps, sources, etc. But never analogue EQ. In fact you usually see old-skool analogue types crapping on analogue EQ because it has a bad rap.

Careful though as setting them all back to zero is very time consuming.

AMIR. There is a very specialized tool for doing this quickly. It is called "a ruler." :cool:
 

nagster

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the meyer cp10s is supposed to be a good parametric eq and a bit more up market than the dbx . not sure about crossover still looking for a good analogue one myself I own this dbx
This is the dashboard of Meyer CP10. It loses to dbx 1231, but it's not bad.
However, ignore Ch2. The bypass relay doesn't seem to switch. This is 28 years old and it's time for maintenance...
By the way, CP10 is made so that input and output are directly connected when the power is turned off. I am relieved that the sound will not stop even if the power cord is unplugged or the fuse is blown.
The successor Galileo and Galileo Galaxy are also easy to use and the sound is transparent. Still, I will continue to use CP10 until it also becomes irreparable. It can be operated quickly and there is no signal delay.
 

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DanielT

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Call me old, call me stupid. Call me dated, call me overly-romantic but I still use a KlarkTeknik DN370 for bass management in my room

View attachment 219829

It's not just the sliders, As a main feature, I am using a built-in narrow notch filter tuned at 32.7 Hz to get rid of the worst resonance peak in my room. Over 200 Hz I let my speakers and my room do the job. I have it hooked in the tape monitor loop of my preamp (I told you I am old style), so that I can switch in a fraction of a second between EQ in and EQ out. Sliders set after many, many REW measurements. I enjoy music 100 times more when it is engaged, Now it's summer, hot weather. Two or three months and I will try a miniDsp SHD to take his place. I don't doubt the new digital boy can outperform my vintage-style analog baby, but it will be obliged to shine before taking that place in my rack.
Almost sounds like you're apologizing for your EQ. Don't do that. HiFi is a hobby and you can do exactly as you want as long as you are satisfied and happy. :)
If I may play amateur psychologist for a second:
I can understand that you have it, it's the boy who played spaceships as a child who now as an adult has a gadget that reminds him of it.
(don't take what I just wrote the wrong way, it was just written for fun, not seriously written)

Besides it is like this. Only prices differ, it's the same dream::D

 
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Andysu

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surprised the dbx 1231 didn't get headless since the dbx drive rack .

i removed behringer FBQ2496 maybe due way i had it connected in the B-chain , oh , months ago and undone the DCX2496 that is still used in the B-chain yet switched totally over to the THX sound system 3417 . i may try the FBQ2496 in the B-chain again and connect only to HF horns where i can use , 1/3 on DEQ2494 with few some PEQ and with FBQ2496 dial in narrow Q bandwidth PEQ frequencies to tackle the most awkward frequncuies with goal of getting them as flat as possible . then use secondary-EQ to adjust for each movie .

main EQ should only serve to flatten the frequency as it is flat or has downward slope or upwards slope when measuring with REW frequency sweep of the amplifier directly of each channel that each overlay just fine . it's the speaker drivers midrange tweeters or HF compression driver to horn the CD needs correct alignment that can take minutes to hours of testing each CD for behind cinema screen , with sine wave tones so they are screwed down correctly so they produce very little harmonic frequencies and once tested over and over again up close with the microphone with frequency sweeps and overlays . they are light-years off target . they need "sandpaper" . just as sandpaper is used to smooth some uneven wood . only EQ has to be always switched on for that wooden speaker driver as no speaker driver is going to ever be perfect flat as the amplifier frequency direct response now . too many peaks or dips , mostly all peaks will be checked and EQ PEQ and only so many bands on analogue EQ and only so many more and less on DSP . the FBQ 25496 can be daisy-chain channel A to channel B but only gets 40 bands to tackle the HF horn and may just do it or needs second FBQ connected so channel A to channel B and B to channel A and B , talk about a large Cray supercomputer as it would take a lot of FBQ to do single channel of AVR .

forget all these autoEQ they still don't do it . i seen everyone's autoEQ rew graphs and still so many bands that have not been addressed . yet sandpaper so cheap to smooth that uneven wood at end of the day .


FBQ4.jpg
 

tomtoo

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Hi Amir
Thanks for this review.
Nice to see that here.

For such a device, an important question is: what kind of graphic EQ correction does this one bring ?
Is that a constant Q ? Or a vary-Q ?
A simple frequency response test at 4 levels on the same graph would bring the answer (and measure the amount of correction): for, say, 1kHz, level at 0, 1/2 max, max, 1/2 min, min.

Another big difference between graphical EQs is: if I push, say, 1kHz to max, then cut 1.25kHz to min and 1.6kHz to max, what is my level at 1.25kHz ?
Some EQ will have level at the middle frequency to 0dB, which may be confusing.

(More explanations between constant Q and vary-Q here)
(EDIT: Another interesting explanation here
and here an example of an asymmetric EQ)

EDIT:
An example of "Q check" measurement

Here, the RME ADI-2 Pro fs R. I tried different boost/cut levels with a "Peak" EQ, 1kHz, Q=9.9, at level -12dB, -6dB, 0dB, +6dB and +12dB
As I've fixed the RME's Q, we see very well the effect of a "Constant Q" EQ: The correction bandwidth is larger if you increase Boost/Cut
Some EQ are more or less keeping the bandwidth constant (and therefore vary the Q with level) or do even more complex tricks (like the Proportional Q in Klark Teknik EQs)

View attachment 219666

Here is what we could get if the EQ is trying to keep the +/-3dB bandwidth constant
Q is now 5.3 at +/- 6dB and 9.9 at +/-12dB

View attachment 219668

Some EQ are even asymmetric, using a different profile for boost and for cut.
(picture from Presonus)

View attachment 219852

So this simple measurement gives us a lot of information...


I've also performed the comparison of the second test I listed:
Alternate max boost/cut on adjacent faders:
Here, still with the RME, I've set 3 EQ to 1kHz -12dB, 1.25kHz +12dB and 1.6kHz -12dB

First with a Q of 9.9 (Max)
View attachment 219671

then with a much lower Q of 2.0
View attachment 219672

The different is stunning, isn't it ?

(NB: It would be more "readable" with frequencies centered around 1kHz, so 800Hz, 1kHz and 1.25kHz)

Thats why i like the eq from neutron player or eq apo it gives you that nice view of the complete correction curve.
 

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Chrise36

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Anyone here has experience with the much cheaper 231s regarding noise clipping etc
 

bYOndo

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hey! great new forum!
pro-oriented gears have two very nice stereo full parametric eqs (a little off topic but we're already talking about analog eq) that I would LOVE to see measured:
Elysia Xfilter (in various "packages", 500, standalone and rack versions) and Drawmer 1974 (only rack version). Both are not "vintage" even they're analogue.
Anyone so kind? :)
 

Jimi Floyd

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Almost sounds like you're apologizing for your EQ. Don't do that. HiFi is a hobby and you can do exactly as you want as long as you are satisfied and happy. :)
If I may play amateur psychologist for a second:
I can understand that you have it, it's the boy who played spaceships as a child who now as an adult has a gadget that reminds him of it.
(don't take what I just wrote the wrong way, it was just written for fun, not seriously written)

Besides it is like this. Only prices differ, it's the same dream::D

I am not taking it the wrong way and I can tell you as an amateur psychologist your performance is outstanding. This is the car of mine I like driving the most...

SLK.jpg
 

anmpr1

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Something like this but with motorized potentiometers for resetting and restoring saved EQ profiles would be a pretty cool toy.
Doing this from a very poor memory about a very limited product run, but back in the day there was a company that made cardboard cut-outs you could use with their EQ. You'd dial in sliders to their intended position, and then cut out a template. Then use the template as an overlay to return all the sliders to whatever position you had previously shaped, if you ever made another adjustment.

I'm thinking it was Soundcraftsman, but I can't say for sure. Soundcraftsman sold an extensive line of graphic EQ, some in full-featured preamplifiers.

The first I ever recall seeing parametric EQ in consumer space was some SAE devices.

EQ in the 'tweako high end' always had a bad name. Minimalism was what was important. Until Mark Levinson and Tom Colangelo modified Dick Burwen's design, and proceeded to sell it for more money than anyone had to spend. Then EQ suddenly became cool, albeit unaffordable. :) With that in mind, go dbx!
 

mdsimon2

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Unfortunately only if you’re using a computer as a source. If you’re not your options are more limited. I use an RME ADI-2 DAC for headphone EQ since I don’t have a computer in my headphone chain, but I’d love it if someone made a dedicated digital-in/digital-out parametric EQ box with a lot of memory slots and more PEQ bands than the RME has.

There are a few all digital boxes that meet this criteria namely miniDSP Flex digital, OpenDRC-DI, SHD, nanoDIGI (used).

Of course need to plug my own preferred solution of RPi4 + CamillaDSP (see signature). You can build a SPDIF digital input / output EQ with a hifime S2 digi and a RPi4 for under $100 with essentially infinite PEQs and configuration slots controllable by an easy to use web interface.

Michael
 
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This is the dashboard of Meyer CP10. It loses to dbx 1231, but it's not bad.
However, ignore Ch2. The bypass relay doesn't seem to switch. This is 28 years old and it's time for maintenance...
By the way, CP10 is made so that input and output are directly connected when the power is turned off. I am relieved that the sound will not stop even if the power cord is unplugged or the fuse is blown.
The successor Galileo and Galileo Galaxy are also easy to use and the sound is transparent. Still, I will continue to use CP10 until it also becomes irreparable. It can be operated quickly and there is no signal delay.
this is really interesting thankyou I'll look into its successors . by the way is it relatively easy to test equipment like this it would be really useful to know if something is producing low distortion or not . what is the minimum equipment required to test gear like this? what level of distortion is considered transparent ? I assumed we should be aiming for around 115db is that to say there are distortion products at 115db below the signal level ?
 
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There are a few all digital boxes that meet this criteria namely miniDSP Flex digital, OpenDRC-DI, SHD, nanoDIGI (used).

Of course need to plug my own preferred solution of RPi4 + CamillaDSP (see signature). You can build a SPDIF digital input / output EQ with a hifime S2 digi and a RPi4 for under $100 with essentially infinite PEQs and configuration slots controllable by an easy to use web interface.

Michael
thankyou did not know minidsp flex had a digital version
 

Cuniberti

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I saw many of these EQs in small venues to EQ the stage monitors or the house speaker system. I believe that's what they are designed for, not a home "Hi-Fi" system.
 

nyxnyxnyx

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can anyone tell me the difference(s) between parameter EQ and graphic EQ? I thought when applied correctly they should be similar.
 

DonH56

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can anyone tell me the difference(s) between parameter EQ and graphic EQ? I thought when applied correctly they should be similar.
Graphic equalizers have a fixed number of frequency band centers with fixed (usually constant) Q. You get a set of sliders for specific frequencies to adjust the amplitude (boost/cut) of each band. IOW the only parameter you can adjust is the amplitude (level) of each band. Common graphic equalizers come in octave to one-third octave models, with octave models covering octave frequency bands (20-40 Hz, 40-80 Hz, etc.) and of course third-octave models have controls one 1/3-octave steps (e.g. 20, 25, 31.25, 40 Hz, and so forth). They are good for broad-band control.

Parametric equalizers allow you to adjust other parameters, typically frequency center, Q (bandwidth), and amplitude. They are more flexible in their ability to fine-tune specific frequencies, but typically have far fewer stages, perhaps four. It is not uncommon for a system/room to have just 2-3 "problem" frequencies so a parametric equalizer allows you to zero-in on and correct those specific frequencies.

Here is a three-band dbx parametric EQ strip -- note each band has a center frequency, Q (bandwidth), and amplitude control:
iu


HTH - Don
 
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