High Pass Filter (HPF) and Low Pass Filter (LPF) Mega Thread

[fdeck]

What's the point of some of these units having volume controls? The last thing I could envision is wanting to adjust sound (particularly accidentally with my feet) another place in my signal chain.

For upright bass, one of the tricks for improving sound is to move away from the amp, whereupon it becomes awkward to reach the volume control while also holding the bass up, on a cramped stage, etc. An extra volume control that you can reach can be useful for experimenting with your setup.

 

[Stumbo]

v

@bdplaid:

Back on point, I had a big rehearsal in a warehouse on Sunday. I am still warming up to the WD, still learning it. Here's a couple of more things I found out:
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1. It was boomy in there, and the HPF got it out while keeping the low end. I was surprised at how effective it was, but it worked.
   
2. The Passive Mid is incredibly powerful. It can change the amp's voicing completely. It's really nice, and I like it better than the Voicing filter on the D series.
3. My singer patted the amp on it's head and said, "I really like this amp." This is most important.

Afterward, I actually read the manual. Well, I skimmed it. I set it up the way Mesa says is it's most neutral - meaning all knobs pointed North. I hadn't done that before, as I thought the Passive Mid, being, well, passive, needed to be full down. With everything straight up, it's killer.

Then I did a comparo to the D800+. No comparison, they are quite different amps. My other fave amp is a Quilter BB800, which was also compared. Still no comparison. The WD seems to do everything I love in the Quilter, only with a broader frequency range. For me, it's kind like once you go WD, you never go back.
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[superheavyfunk]

What's the point of some of these units having volume controls? The last thing I could envision is wanting to adjust sound (particularly accidentally with my feet) another place in my signal chain.

I use the volume knob on my H+LPF to goose the signal thru the rest of my pedals down the line. It sounds to my ears that after "turning down" the lowest lows and the highest highs and then goosing the level, that I end up with a bit of a mid boost... Even if that's not what's actually happening, it still sounds pretty darn good so the technical aspect of it all doesn't mean much to me.

Also, I dont tend to stomp pedals on and off during songs, so I'm not worried about accidentally moving any knobs with my foot.

 

[Stugilliam]

You said 35 years ago. In my case it's been over 50 years and HPF's were an unknown back then. I am guessing that drivers back then (and possibly even amps) were not capable of producing those low frequencies. We were dealing with 60 to 100 watt amps (tube and solid state) and drivers like the JBL D140F. I don't recall problems with booming and even without booze and drugs, we made do. I believe the amps and drivers of today are capable of a lot more and I use an HPF. Even with my hearing problems, an HPF with my equipment (see signature), is necessary. I am open to correction, however !

True I did say 35 years,, but, like you, I started playing in the summer of 1965. And I still have one of my Ampeg 2x15 cabinets in the basement, loaded with JBL E140's and a pair of JBL Cabarets, which are factory loaded with JBL E140's so I know whence you speak.

 

[GwenOnBass]

One may postulate had Jack Bruce used a HPF in the Creme era, no bass sounds would remain to amplify

 

[Blues Bass 2]

I want to use one of the HPF filters with my Ampeg PF800 , probably one of fdecks . I don't have any pedals or a pedalboard so I plug staight into my head . I would use it into the effects loop and velcro it to the top of my amp head but having to have a seperate powersupply would complicate my 120V power setup . Anyone have a good solution ?
If I have to I may have to go to a Pre/power setup again because the Crown XLS poweramps have a HPF in their DSP display , really a 24db crossover , and I could just get a Sansamp RBI again . I really love the power and simplicity of the PF800 but don't know if I want the extra hookup hassles of a HPF .

 

[MarkA]

I want to use one of the HPF filters with my Ampeg PF800 , probably one of fdecks . I don't have any pedals or a pedalboard so I plug staight into my head . I would use it into the effects loop and velcro it to the top of my amp head but having to have a seperate powersupply would complicate my 120V power setup . Anyone have a good solution ?
If I have to I may have to go to a Pre/power setup again because the Crown XLS poweramps have a HPF in their DSP display , really a 24db crossover , and I could just get a Sansamp RBI again . I really love the power and simplicity of the PF800 but don't know if I want the extra hookup hassles of a HPF .

You can run the HPF3 (the version I'd recommend for electric bass) off a 9-volt battery, if you like. (Carry a spare battery if you do, and don't have anything plugged into the HPF's input when you're not using it, or you'll run down the battery.)

If you don't use a battery, you'll have to power the HPF3 with something -- a One-Spot or whatever. Maybe one of those "splitter" type AC cords (plus the One-Spot and a zip-tie) would simplify your setup?

If you really wanted to, you could run the HPF off of one of those rechargeable, 9V "bricks".

You can certainly run a rack setup -- I do that sometimes and, HPF aside, you might find other advantages to it -- but I wouldn't say that you have to do that if all you want to do is add the HPF.

 

[Mushroo]

If you don't use a battery, you'll have to power the HPF3 with something -- a One-Spot or whatever. Maybe one of those "splitter" type AC cords (plus the One-Spot and a zip-tie) would simplify your setup?

Not specifically for the HPF3, but when I want to run just 1 pedal on top of my amp head, MarkA's suggestion is exactly what I do: TrueTone OneSpot and Courtesy Plug.

 

[Stumbo]

I want to use one of the HPF filters with my Ampeg PF800 , probably one of fdecks . I don't have any pedals or a pedalboard so I plug staight into my head . I would use it into the effects loop and velcro it to the top of my amp head but having to have a seperate powersupply would complicate my 120V power setup . Anyone have a good solution ?
If I have to I may have to go to a Pre/power setup again because the Crown XLS poweramps have a HPF in their DSP display , really a 24db crossover , and I could just get a Sansamp RBI again . I really love the power and simplicity of the PF800 but don't know if I want the extra hookup hassles of a HPF .

Before I picked up the Broughton Always-On(no switch) HPF, my thoughts were the same as yours.

What I found after I received it, it is so tiny that it fits pretty much anywhere. I put it on top of my amp or combo. Wherever I plug my amp in, I plug in the HPF Truetone Onespot power supply. My combo is old school so it has a outlet in the back. Depending on how for the wall outlet is, sometimes I use a power bar and run its cord to the plug, with an extension cord, if necessary. I carry the extra stuff anyways so it's no big deal.

I also run my bass cord through the handle, into the HPF and then into the amp. If works great!

Edit: I checked out the TrueTone Courtesy plug. Next on my list.

 

[sears]

I wonder if that courtesy plug works with other devices.

 

[Mushroo]

I wonder if that courtesy plug works with other devices.

It's a standard 3-prong electrical outlet that you can use for any device. Effects pedal, phone charger, light, fan...

 

[Blues Bass 2]

Thanks guys , I'll probably use it with a battery , probably the HPF3 .

 

[Stumbo]

v

@estimated_eyes :

I typically use a Countryman Type 85 to send to FOH (if they want to mic my cab, great!). Send the DI right after my pedalboard.

Because I am using fuzz and overdrive, I have a L/HPF at the end of my pedal chain to cut off the unwanted lows and highs that come with running at line level.

Have spent hours playing this exact setup through cans/boards to emulate what I would be sending to FOH, and it sounds good to me. I have only gotten compliments at gigs.

 

[Stumbo]

v

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@Mike Arnopol:

Just got mine. (Euphonic Audio iAmp Classic 1200 watt)
It's what I expected----and my expectations were very high. Best EA amp yet. One area where it's exceeded my expectations. They beefed up the power supply. Lots more capacitance. Comparable to the custom Pascal I'm using in my powered cabs. In a head-to-head, the Pascal had a little advantage in the power/slam department. The Ice had a small advantage in the fidelity department. With the beefed up power supply----not much difference in power and slam. I wish it were smaller---I'd use the Ice in my cabs. But they're both very close.

One area that was a disappointment. I was stoked that it had a HPF. It's not too useful. It's set at 20 hz and I think that it's 6db/octave. I want to stop calling what I'm talking about a HPF. It is, but a better name would be a subsonic filter. A subsonic filter is a HPF, but a HPF is not necessarily a subsonic filter. A subsonic filter needs to be 24db/octave and at least for 5 string bass---set no higher than 30hz and no lower than 27hz. With my speakers, my 28hz hpf gives me more than 3db more output in the low end. With no degradation in signal. In all pro-sound equipment that I know use 24db/octave. My Symetrix, Ashley, and Klark Technik Eq's all have variable 24db/octave HPF's. If someone wants variable--buy a pedal. If you want to effectively double your output---a fixed 28hz hpf will do it.

I think that the new Classic is a huge winner and a steal at that price. I wanted a neutral powerful amp that was not sterile--just the right bit of warmth. This amp kicks butt. BTW---I would be hesitant to run it at 2 ohms. I run mine at 2.67 all day with no problem, but I'm wary of 2. I very well might be wrong.[/QUOTE]
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[Stumbo]

v

@CalBuzz51:

When this band started I was playing Mesa 400+ and Paradise 115. Each piece was 60lbs and awkward. Now each 210 is 30lbs and I can carry them both in one trip. The sound is way better too, especially turned up. I could not dial out serious midrange blast on previous setup. Now with Mesa 800+ hpf I can tune lows perfectly, and 410s go much lower cleanly than the 115 could (duh).[/QUOTE]

 

[Stumbo]

late to the party on low/high pass filters

 

[Zbysek]

Look who's arrived!

 

[Karl Kaminski]

ahhh, gimme gimme gimeme!

nice get!

 

[CallMeAl]

Looking for tips on my new hpf, if anyone wants to stop by my thread I'd sure appreciate it!

HPF Tips?

 

[Stumbo]

v

@LeonD:

And sometime, "normal" eq alone can't handle a boomy room.

That's when it's time to bring out the isolation pads for the cabs and High Pass Filters (HPF) for the amps.

Not unique to the Quilter BB800. I've had to do this with everyone of my amps.