B7K & BDDI eq and blend measurements

[crguti]

I've got some free time in the lab so I measured the EQ & Blend frequency response of the Darkglass B7K and Sansamp BDDI. Hopefully someone will find this interesting.

Darkglass B7K:

Below settings display the flattest response (fat red curve). Blend and Drive are at minimum and both switches are in the middle.

B7K EQ measurements: Each knob was placed at minimum and at maximum keeping the rest at flat position.

B7K Blend measurement: Blend knob was gradually increased from blend 0 (minimum) to blend 6 (maximum). blend 3 correspond to 12:00hrs position. Drive is at minimum and EQ are in flat position.

Sansamp BDDI:

Below settings display the flattest response (fat red curve). Blend and Drive are at minimum.

BDDI EQ measurements: Each knob was placed at minimum and at maximum keeping the rest at flat position.

BDDI Blend measurement: Blend knob was gradually increased from blend 0 (minimum) to blend 6 (maximum). blend 3 correspond to 12:00hrs position. Drive is at minimum and EQ are in flat position.

 

[ProfFrink]

Very interesting...

QQ: Can anyone explain why the phase of the BDDI behaves like it does towards the end...? Naively, I would assume this is how a fixed-latency phase-response might look like, but surely this is all analog...? Maybe the measurement apparatus introduces some latency...?

 

[ProfFrink]

Very interesting...

QQ: Can anyone explain why the phase of the BDDI behaves like it does towards the end...? Naively, I would assume this is how a fixed-latency phase-response might look like, but surely this is all analog...? Maybe the measurement apparatus introduces some latency...?

Or maybe this is just one cycle and it's "blurred" because the phase response is "noisy" (i.e. changes a lot)

 

[crguti]

^ see the response, it decreses -20dB so introduces noise.

 

[ProfFrink]

^ see the response, it decreses -20dB so introduces noise.

Got it. Thanks!

 

[ilansgroove]

Why did u guys start a thread in Chinese ?

 

[father of fires]

This is amazing! What tech did you use to make the measurements?

 

[crguti]

This is amazing! What tech did you use to make the measurements?

I just used an FFT Analyzer in the Brüel & Kjær Pulse Labshop.

 

[NKBassman]

The massive scoop at 800 Hz with no EQ point to correct it is exactly what I have grown to despise about the Sansamp.

 

[NKBassman]

Very cool to see, though. Thanks for posting.

 

[BigBobbyBass]

The massive scoop at 800 Hz with no EQ point to correct it is exactly what I have grown to despise about the Sansamp.

Same here.. It was ok, until I discovered mids..

 

[Deadsound]

Very interesting, thanks for posting! This confirms what many B7K users already know, namely that it can achieve a lot of tones and to call it "mid scooped" is overly simplistic.

 

[ticol07]

The blend 3 BDDI curve (orange) is strange. It's the only one with this big dip between 4 and 5 khz.
Interesting curves by the way.

 

[father of fires]

The massive scoop at 800 Hz with no EQ point to correct it is exactly what I have grown to despise about the Sansamp.

I actually like the scoop in the Sansamp. It works great for specific tones.

The 800-ish Hz scoop in the Sansamp works great for thick rock tones but is too warm and you get lost in the mix easily. The Presence control allows you to boost 2kHz to help cut but sometimes it's not enough.

The 300-ish Hz scoop in the B7K and the fierce peak around 2kHz works great for bright cutting tones and is less warm but sits nicely with heavy rock/metal guitars.

Both sound great for different things.

 

[Hallic]

Really appreciate data like this. You get a visual reference for what you are hearing. Which is handy when talking about sound to other people.

Could you do a graph of how the grunt and attack switches affect the frequency response? (and if you have a VMT on hands: the era knob! )

 

[Fuzzbass]

Just curious why you didn't test Presence on the BDDI. Is it because it's boost only?

 

[crguti]

^ the presence was similar to the the treble and above 12:00 it just add noise.

 

[CoarseBass]

Maybe this will hush the Darkglass mid scoop crowd...

Looking forward to spending some time with this on something bigger than my phone.

Great post.

 

[Fuzzbass]

I actually like the scoop in the Sansamp. It works great for specific tones.

Agreed.

Back story: many bass amps have some built-in scoop even when flat -- because many like it (the Fletcher-Munson thing), especially with a passive bass. If the amps aren't scooped outright, then they often have some sort of switch/knob to allow that scoop: Ultra-Lo, Contour, Enhance, whatever. The SansAmp is set up to have that scoop, and it works: for decades it has been an enormous hit as DI in pro recording studios. A big problem can happen when putting it before a scoopy bass rig (everyone remember SWR?): that can result in excess scoop.

Regardless: as noted, the further you crank Blend, the more scoop you get. To minimize scoop, roll Blend back. When using RBI or BDDI, I've always kept Blend between noon and 2 o'clock.

 

[NKBassman]

Many like it, and I used an RBI for years. I just grew to really dislike it more and more over time. If I had cash to spare for excess gear these days, I'd keep one around.

I actually used an RBI rig at someone else's jam space a few weeks ago and ended up having to dial the blend back to about 9:30-10:00 before it started sounding "natural" to me again.