Low Pass Filter: Do You Use It?

PANDAPANDELO · #1 05-02-2020, 06:29 PM

Hi there, everybody!

I'm using a Martin HD28 with LR Baggs M80, into a HX Stomp (I'm finally with it again! After a few problems I had, Line 6 guys repaired it and now everything is working perfectly). I'm using the IRs Cuki made with my Martin and a Schatten HFN Passive captured with an AT2035 (yes... I gave up on the HFN Pickup... mine came with some problem, and I'm from Brazil, so the exchange is a hard possibility).

I have noticed, while working on my EQing, that my guitar sound was a lot warmer than it was plugged in, and I had to put a Low Pass Filter in 10k, to get the tone a lot closer to my unplugged sound.

I would like to know if any of you have experienced this. I'm new at EQing things, and I always heard of people boosting the top end, not cutting. But, to my ears, the sound get a lot warmer and less strident in that way.

It would be nice if you could share your experiences and opinion. Thank you very much!

Cuki79 · #2 05-02-2020, 11:21 PM

Hi Rodrigo,

I think your IR predates the new Match process, so your IR response should look like that. There are some very sharp ringings above 10 KHz. (sharp peaks)

Those resonances that might have been appropriate with your HFN pickup are not with the M80.

Note that the M80 it-self is very different by nature from the HFN. It is a humbucker magnetic pickup with a suspension on the secontary coil.... This is nNothing like the HFN which is a piezo on a 3D-printed post.

The IR that you use is not appropriate. Because you are just adding kHz ringings and try to remove it later on with your Low-pass filter...

Just make some new recordings and I'll make new IRs.

Note that IRs are not compatible with mic pickup in general... so the result will be less spectacular than with piezo pickups.
... I never did IRs for mag pickups but James May wrote once that some customers were happy to use Tonedexter with mag pickups, so we can give it a try.

Do a regular recording so I can make an IR in the "normal" way. And please make an additional one playing only one strings (ex: the low E strings at each position), so we can get rid of the comb filtering effect.

Cheers,
Cuki

Brent Hahn · #3 05-03-2020, 01:40 AM

The LP filter is very powerful. Here's a recording I did with one acoustic guitar -- no electrics -- check out the "lead guitar" at around 1:40. The filter was down into the low 100's. All guitars on this track are the same, a 70's Ibanez lawsuit dread.

Cuki79 · #4 05-03-2020, 04:06 AM

Quote:

Originally Posted by Brent Hahn

The LP filter is very powerful. Here's a recording I did with one acoustic guitar -- no electrics -- check out the "lead guitar" at around 1:40. The filter was down into the low 100's. All guitars on this track are the same, a 70's Ibanez lawsuit dread.

Do you refer to LP or HP. A low-pass filter set to 100Hz cuts almost everything....

PANDAPANDELO · #5 05-03-2020, 06:36 AM

Cuki... THANK YOU! I will make the recordings today!

And, just for you know... even with the "wrong" IR, the sound I get with my M80 is REALLY close to my unplugged sound. That's why I was giving it a shot. Maybe we could make it sound even better with the new IR!

I will make the recording and send it to you! THANK you!!!

varmonter · #6 05-03-2020, 08:03 AM

when i had a tonedexter i recorded
the irs using a kk . When i played
out i used my m80 thru the td.
It sounded good. Now like you
i have a helix stomp. i use a 3sigma ir
Martin 45 i think. It sounds pretty good.
So cukis irs built to your guitar should
be even better.. The filters i would play
with and just adjust to what sounds good to you..Glad you got your stomp back ..

PANDAPANDELO · #7 05-03-2020, 08:49 AM

Yes, Varmonter! I'm glad I have the Stomp back! I'm messing around with the possibilities! I'm a lot happy with Cuki's and Jon's IRs.

I got me the Sigma, too. But, to my ears, the Cuki's and Jon's are more like my guitar. Not that the Sigma are bad... they are just not sounding like my guitar... and that can be a good or a bad thing.

The M80 is a great pickup. The looks, the lush on the sound... it got a jazzy tone on it, that I love. And the IRs take out a lot of the bad mid frequencies (for me, somewhere around 250 and 700hz), making it even more pleasing. I'm really happy with the tone I'm achieving. The only think I'm missing now is a more stereo sound... but I think that it is not possible.

Brent Hahn · #8 05-03-2020, 09:35 AM

Quote:

Originally Posted by Cuki79

Do you refer to LP or HP. A low-pass filter set to 100Hz cuts almost everything....

A very steep Low Pass filter. I'd have to open up the session to tell you for sure, but it's probably cutting off everything above 900 Hz or so.

Villamarzia · #9 05-03-2020, 09:40 AM

Quote:

Originally Posted by Brent Hahn

A very steep Low Pass filter. I'd have to open up the session to tell you for sure, but it's probably cutting off everything above 900 Hz or so.

How can a guitar possibly sounds good with nothing above 900hz?! There must be something wrong or I am totally ignorant (which I am, but hopefully not totally..)

Brent Hahn · #10 05-03-2020, 09:53 AM

Quote:

Originally Posted by Villamarzia

How can a guitar possibly sounds good with nothing above 900hz?! There must be something wrong or I am totally ignorant (which I am, but hopefully not totally..)

It's one of those situations where you just listen, you don't look at the GUI or think about reasons why it shouldn't sound good. And if you insist on being scientific and rational, the slope of the filter is 24 dB per octave so the stuff above the cutoff point is down 24 dB at 1.8 KHz, 48 dB at 3.6K and so on, but not entirely gone.

Villamarzia · #11 05-03-2020, 10:15 AM

I see, maybe we are talking about different things. I am referring to a “natural” sound and you are referring to a “good” sound. Not necessarily the same thing. Above 900hz there is 1/3 of the sound of an acoustic guitar (see chart below), it’s where presence and trebles are. But below there is the body and the lows. Could be interesting to experiment and chop the frequency range in some context such as yours.

Peter Z · #12 05-03-2020, 10:44 AM

I use the lowpass filter on my HX Stomp all the time.

Brent Hahn · #13 05-03-2020, 10:50 AM

Quote:

Originally Posted by Villamarzia

I see, maybe we are talking about different things. I am referring to a “natural” sound and you are referring to a “good” sound.

Right. And in the example I posted earlier, if I didn't tell you how it was done you'd never know it wasn't "natural."

varmonter · #14 05-04-2020, 08:18 AM

Personally the term natural is interpreted
differently by everyone. Some think
as soon as its not totally acoustic its no
longer natural. Others strive to get a natural sounding tone by selective eq
and hp/lp filtering.
We can all strive for "my guitar only louder"
And ive heard some come close.
And some not so close. It is all good.
There is a sweet spot way up there that to me adds
sparkle in a live performance and helps the guitar
Cut through in a mix. For me.. im just careful enough not to
Squash this. The other end is just as important ..A low freq that sounds neither boomy nor muddy but stand out with a bit of spl.
I think it a matter of "ear" to acheive this. And a matter of knowing
what to do to fix it when its not there.