How important is the sidechain HPF for a bass compressor?

[colin0154]

This year I'd like to upgrade my comrpessor pedal, but I can't seem to decide between Empress Bass Compressor and the Trickfish VCA Compressor. One of the difference is the variable sidechain HPF.

I know how sidechain HPF works, which only affects the detect signal, but I'm wondering how important is that? Why isn't it a norm for the bass compressor?

Or is it possible that most compressors designed for bass have some fixed HPF built in the sidechain?

 

[jdjk7]

I know how sidechain HPF works, which only affects the detect signal, but I'm wondering how important is that? Why isn't it a norm for the bass compressor?

Or is it possible that most compressors designed for bass have some fixed HPF built in the sidechain?

I would say that having some sort of HPF is fairly important for a bass compressor. As for why it's not a norm... well, now it sort of is, at least for compressors that are considered to be well designed by the bass cognoscenti.

I wouldn't say that having a variable HPF is critical. To me, having a variable filter is mostly good if you want to be able to optimize the compressor to different instruments.

I don't know the specifics of many bass compressor designs, but it's possible that many do feature a fixed hpf. Though, without any sort of mention of it in the manual, it's hard to tell without actually tracing the thing out and knowing what you're looking at. The only comp that I can think of off the top of my head that uses a fixed hpf is the Broughton Omnicomp. FWIW, the Omni is my preferred compressor, even compared to the Empress.

 

[Zooberwerx]

This year I'd like to upgrade my comrpessor pedal, but I can't seem to decide between Empress Bass Compressor and the Trickfish VCA Compressor. One of the difference is the variable sidechain HPF.

I know how sidechain HPF works, which only affects the detect signal, but I'm wondering how important is that? Why isn't it a norm for the bass compressor?

Or is it possible that most compressors designed for bass have some fixed HPF built in the sidechain?

This is a specific feature that will be embellished in the ad copy or specs IME. I played around with both options (signal path vs side chain) on the Empress v1 and, in the interest of simplicity / ease / outcomes, preferred a separate HPF in the signal path. That being said, you can do some really neat stuff with the side chain (e.g. synching with the kick drum) which may go largely unnoticed depending on the application or scenario. It's a lot of fun, you won't break anything, but there's always a threshold of diminishing return.

Riis

 

[NKBassman]

This year I'd like to upgrade my comrpessor pedal, but I can't seem to decide between Empress Bass Compressor and the Trickfish VCA Compressor. One of the difference is the variable sidechain HPF.

I know how sidechain HPF works, which only affects the detect signal, but I'm wondering how important is that? Why isn't it a norm for the bass compressor?

Or is it possible that most compressors designed for bass have some fixed HPF built in the sidechain?

I don't know if I would describe it as "important", but it can have a significant effect on how the compressor reacts to your incoming signal.

What some see as important, versatile, or essential control features, others might call over-complicated or distracting. Comps, more than almost any type of pedal, seem to have a very widely varying control set depending on the individual pedal. I've had comps with Sidechain HPF controls, but most without. Some with Attack and Release controls and some without, fixed threshold or variable, fixed ratio or variable, optical or VCA, parallel clean blends, clinically clean or coloured sound profile... they all work. What's "important" just depends on your use case and context.

At the end of the day It's just another tweakable variable which may or may not be important to what you want to get out of the pedal.

 

[lomo]

IMHO it's important enough for a low B string that if I was buying a new comp that would be my only or main comp, I'd want it. I have the Empress and it is my main comp. I also have the Diamond, which I love, but If I had to have only 1, it'd be the Empress (not only because of the side chain feature). For a 4 banger in standard tuning I'd prefer to have it but it wouldn't be a deal breaker.

 

[MCS4]

Not "important," in my opinion, although theoretically useful, and nice to have. I use the Empress Bass Compressor and don't really mess with the HPF, and I didn't miss having one at all when I used a Keeley Bassist.

 

[ole Jason]

Not important to me

 

[JamesGrant]

Most compressors do NOT have a filtered sidechain, if they do they highlight it as a feature.

Is it important? Depends on what you want the compressor to do. If you get one with the feature and don’t use it, you’ll know if it’s useful. If you get one without the feature then you’ll always wonder.
Personally, my bass isn’t super bassy and so I don’t (currently) have a compressor with HPF sidechain, and I don’t miss it.

 

[micguy]

The side chain high pass is important. Also important (more important, probably) is control over time constants - different people use compressors differently, and if you can't change the attack and release time constants, you're limited in how you can use the thing. I use mine to grab attacks and bring them down a bit - fast time constants are key to doing that well. I have also used compressors at FOH to grab stuff after the attack (leaving the attack alone) and hold notes a bit longer. Slow time constants are absolutely needed to do that well. The Empress is flexible enough to do either of those. The Trickfish? No idea what it can and can't do well - it has time constants, of course, but you have no control over them. It may do exactly what you want, but you won't know until you try it. The Empress will do what you want.

 

[logdrum]

I do not have experience with Empress or how this is implemented with HPF but the only time I've seen side chain used was with the kick drum possibly the snare during mixing. Grooves are punchier that way but still depends on the bass player and the drummer. Of course with drum machines and synths it's not necessary

 

[FullumMusic]

How often are you side-chaining through your pedal?
When you're side-chaining your pedal, how ofter do the low frequencies from the source cause issues setting the compressor parameters?

Depending on how you answer those will tell you how important having that feature is for you and your compressor pedal.

 

[BassmanNate]

Definitely a nice to have but certainly not a requirement. I've got the Empress and it's really nice if the low end is getting clamped down on but the signal is otherwise fine, I just roll up the filter to open it up instead of playing around with input/output gain, etc.

 

[silky smoove]

How often are you side-chaining through your pedal?
When you're side-chaining your pedal, how ofter do the low frequencies from the source cause issues setting the compressor parameters?

Depending on how you answer those will tell you how important having that feature is for you and your compressor pedal.

These comments apply to an external sidechain, which is obviously different from a filter applied to the internal sidechain to the detector circuit. This highlights a crucial use case difference not identified in the OP.

If I need an external sidechain, then obviously it’s imperative. If we’re just discussing an internal HPF sidechained to the detector circuit… meh… I used to think it was critical, but after owning many compressors with this option I’ve not found them to be as important as I previously thought. Potentially nice to have when using an instrument with a ton of low frequency content, but even then it’s not mandatory for me.

 

[silky smoove]

I've got the Empress and it's really nice if the low end is getting clamped down on but the signal is otherwise fine

Not sure if this was your intention or not, but for separation of compression across frequency bandwidths you’d need a multiband compressor, which the Empress is not.

 

[Wasnex]

This year I'd like to upgrade my comrpessor pedal, but I can't seem to decide between Empress Bass Compressor and the Trickfish VCA Compressor. One of the difference is the variable sidechain HPF.

I know how sidechain HPF works, which only affects the detect signal, but I'm wondering how important is that? Why isn't it a norm for the bass compressor?

Or is it possible that most compressors designed for bass have some fixed HPF built in the sidechain?

All compressors have a sidechain. However, many do not allow user access to the sidechain.

Pretty sure pedal designers tend to build in whatever EQ curve they think is best. Access to the sidechain allows the user to modify the way the compressor responds and tune it to taste for different situations. If a compressor already does what you want and you have consistent expectations, there is no need benefit to having access to the sidechain...it just adds expense.

Having access to the sidechain may make one pedal better for your needs...or it may not. Access to the sidechain is just one of many things you could consider. Unfortunately, the only way for you to know for sure which you like best is to actually experiment with both pedals.

 

[Wasnex]

These comments apply to an external sidechain, which is obviously different from a filter applied to the internal sidechain to the detector circuit.

External sidechain? AFAIK we are basically discussing an insert on the internal side chain.

 

[MikeBass]

I’d look into a multiband compressor.
The old school Trace Elliott Dual band compressor was/still is at the top of my list for compressor pedals.
Phil Jones makes on and I believe Mark Bass may as well.
I personally would far prefer that over a side chain HPF.

 

[silky smoove]

External sidechain? AFAIK we are basically discussing an insert on the internal side chain.

View attachment 7442094

An external side chain source would be more accurate relative to the post I was quoting where I reference another use case for the sidechain input on the Empress which bypasses its internal sidechain HPF.

 

[BassmanNate]

Not sure if this was your intention or not, but for separation of compression across frequency bandwidths you’d need a multiband compressor, which the Empress is not.

No, I understand the sidechain functionality. Just removes the lower frequencies from the sidechain and so they don't affect the compressor. More energy in the low frequencies and so they tend to cause the compressor to engage at lower volumes.

Multiband compression would imply that we're also applying a separate compression ratio to the lower frequencies which the Empress doesn't do. Turning that filter up on the sidechain does have the effect of freeing the low frequencies, though.

 

[silky smoove]

Turning that filter up on the sidechain does have the effect of freeing the low frequencies, though.

Yeah, this is the piece that makes no sense, and I've even discussed it with the folks at Empress regarding their ad copy surrounding it. The compression is applied to the entire signal bandwidth anytime the signal amplitude exceeds the threshold. If it's compressing, the low frequencies are treated identically to all other frequencies. If it's not above the threshold, then everything is passing through without compression, regardless of frequency. This notion of some frequencies being freer, or as their older ad copy stated "being bottomless" doesn't really make any sense from an engineering perspective that I've ever been able to comprehend, and I say this as a professional working audio engineer.