Behringer BDI21 missing switches.

[Stub Mandrel]

Just got a Bheringer DI box, back of the leaflet shows example emulation of several amps, using three switches which aren't on the box!

 

Presumably this is from some past iteration, or something.  Does anyone know  and is it possible to'retro fit' these to the pedal?

 

A

[jrixn1]

Dunno what's going on with your manual, but those looks like they're for guitar version, GDI21.

 

[Stub Mandrel]

Just downloaded the GDI21 manual -= it even has the 'slap bass example', so my pedal has the wrong back page. How odd.

 

 

[BabyBlueSound]

On 22/08/2021 at 20:26, Stub Mandrel said:

Just downloaded the GDI21 manual -= it even has the 'slap bass example', so my pedal has the wrong back page. How odd.

 

 

 

I just bought the BDI21 and I got the GDI21 switches in the manual too.

 

[Supernaut]

I always struggle to get a good setting out of my BDI21 - sounds scooped no matter what knobs I turn! 

[Jack]

17 hours ago, Supernaut said:

I always struggle to get a good setting out of my BDI21 - sounds scooped no matter what knobs I turn! 

They're very scooped but in fairness so is the original model Sansamp Bass Driver that they're based on. The mid point is pretty much fixed so if you turn both treble and bass down quite a way then you can eliminate it somewhat. The Paradriver (oh the Behringer Acoustic DI copy) have way more mids.

[Supernaut]

1 hour ago, Jack said:

They're very scooped but in fairness so is the original model Sansamp Bass Driver that they're based on. The mid point is pretty much fixed so if you turn both treble and bass down quite a way then you can eliminate it somewhat. The Paradriver (oh the Behringer Acoustic DI copy) have way more mids.

 

I remember this video doing the rounds a while back - extremely close and would be impossible to tell in a live situation. 

 

 

[MacDaddy]

On 21/11/2021 at 15:40, Supernaut said:

I always struggle to get a good setting out of my BDI21 - sounds scooped no matter what knobs I turn! 

 

can't say that's ever been an issue for me, though it is a common complaint.

[BabyBlueSound]

I personally like a somewhat scooped sound. Does playing with the BLEND knob help? If you turn it down, it's supposed to soften the "effect" and bring back more of the mids of your original sound.

[atsampson]

On 21/11/2021 at 15:40, Supernaut said:

I always struggle to get a good setting out of my BDI21 - sounds scooped no matter what knobs I turn! 

The BDI21 will always give you a mid scoop, unless the footswitch is pressed or the Blend control is at 0%.

 

Here's what my BDI21's frequency response looks like with Blend at 100% and all the other controls at 50%:

 

 

There are effectively two sections of the BDI21 - the amp simulator controlled by the Drive and Presence controls, and the EQ controlled by the Treble and Bass knobs. The Blend knob bypasses the amp simulator, and the footswitch bypasses the whole thing.

 

The whole of the frequency response above, including the huge 800 Hz notch, comes from the amp simulator, so if you want less mid scoop, turning down the Blend control will do it. When Blend is at 0% and Treble and Bass are at 50%, the frequency response is more or less flat.

 

Something I didn't realise until I measured it was that the Presence control's behaviour is a bit non-obvious - turning it up applies a few dB of treble boost, but it also significantly reduces the depth of the notch. Here are overlaid frequency responses with Blend at 100% and Presence at 0%, 25%, 50%, 75% and 100%:

 

 

So if you like the drive effect but want less notch, another option is to turn Presence up all the way, then turn Treble down a little to compensate for the treble boost...

 

[BabyBlueSound]

15 hours ago, atsampson said:

 

So if you like the drive effect but want less notch, another option is to turn Presence up all the way, then turn Treble down a little to compensate for the treble boost...

 

 

Thanks for the visualised measurements, this is awesome, and for the tips. How do you measure the frequencies like this?  I am yet to try the pedal with rounds, so far I have only used it to funk up the black tape sound, and loving the results. I guess these frequencies would look a bit different with tapes, since the amp simulator works from a different original sound? I'd love to see.

[Jack]

8 hours ago, whave said:

 

Thanks for the visualised measurements, this is awesome, and for the tips. How do you measure the frequencies like this?  I am yet to try the pedal with rounds, so far I have only used it to funk up the black tape sound, and loving the results. I guess these frequencies would look a bit different with tapes, since the amp simulator works from a different original sound? I'd love to see.

No, unless @atsampsondid something very unusual then you usually feed a spectrograph a pink noise signal, which is equal amounts of every frequency(ish). Meaning that this is the response of the pedal, there was no bass guitar involved here.

[atsampson]

12 hours ago, whave said:

How do you measure the frequencies like this? [...] I guess these frequencies would look a bit different with tapes, since the amp simulator works from a different original sound?

You feed white noise into the input, and look at the output with a spectrum analyser - I used JAAA on Linux here, but lots of tools can do the same job. White noise contains an equal amount of energy at each frequency, so it produces a flat line if you connect the generator directly to the analyser; put the pedal between them, and you can see what effect it's having at each frequency. As Jack says, pink noise is the same idea but it has an equal amount of energy in each octave; you could do the same thing with a pink noise generator, if you scale the graph in a different way.

 

The BDI21 is a pretty simple device, and its frequency response shouldn't change (much) depending on the input - it'd be a different story for something like an envelope follower pedal where the equalisation it applies changes based on the amplitude of the input signal.