Emi Issues

[jasong]

Except that isn't exactly what is happening since Phrunt said on page or 2 or 3 that Pat claims there is no equalization occuring in the SP01.

I'm not sure people read my post very closely. I'm sure the booster is doing something. Clearly. If it's not equalization, it's compression or noise filtering, or both. I understand the amp after preamp concept, but I don't personally see the distortion that would necessitate following the GPZ with another amp, and this is part of my confusion, since clearly others do.

What I'm unsure about is if it's doing anything that can't be achieved simply by using the onboard GPZ controls more judiciously or by not following religiously the settings JP posted. For example: I don't experience distortion above 8 volume, but I also don't run my threshold at high levels (and I often use low smoothing), I'm usually below 18 and sometimes down to 6 or 8, while JP recommends 27 minimum and no smoothing. This might be irrelevant except that from what I can tell, everyone using this SP01 seems to be following JP's advice judiciously, which means running very high thresholds, and with unprocessed noise from no smoothing, which themselves may be causing this distortion that doesn't seem to happen to me.

If the SP01 is simply compressing or filtering the audio to get this "brightness" then you are losing data in the audio stream in the exact same way you would as if one simply ran a lower threshold or used low audio smoothing, which seems to contradict the point of running those GPZ settings to begin with. In fact, running a lower threshold may sometimes bring out that tiny signals that get wiped out by the higher threshold levels, and then completely erased by filtering on top of that.

What I'm trying to figure out is if a person needs to spend $250 more and hang another object off their chest just to achieve the same effect one can get for free, and with one less accessory, just by using the onboard GPZ processing. Or if this SP01 is actually doing something unachievable within the GPZ controls (apart from the boosting).

Next time I meet someone in the field I'll just have to test it myself I think because something isn't making sense to me here. I get the SP01 for a detector that lacks the audio processing of the GPZ, but I wonder if people sticking to other people's settings is causing some of the perceived need for the SP01 on the GPZ. 

[Chase Goldman]

6 minutes ago, jasong said:

Except that isn't exactly what is happening since Phrunt said on page or 2 or 3 that Pat claims there is no equalization occuring in the SP01.

That's just semantics.  Pat says in his own post that it "manipulates" the audio.  Whether you call it equalization, filtering, or coloring those are all just imprecise terms for audio manipulation.  

[jasong]

19 minutes ago, Chase Goldman said:

That's just semantics.  Pat says in his own post that it "manipulates" the audio.  Whether you call it equalization, filtering, or coloring those are all just imprecise terms for audio manipulation.  

Equalization is very different from noise filtering which is very different than compression. These things matter. 

The reason it's relevant here specifically is that the GPZ lacks any equalization ability. But in the GPZ you can emulate (kinda) a compressor with the volume limit, threshold, and volume. And the audio smoothing function is more or less a noise filter. 

15 minutes ago, phrunt said:

Well I doubt JP would be tailoring his settings to the SP01 and it's filters seeing he's got a competing product that he sells, the B&Z is just a plain old audio amplifier, no filtering or messing with the audio, just boosts the volume for you and gives you a volume control knob. 

Right, I'm not saying JP tailored his settings for the SP01. I'm asking wether the settings he runs/recommends are settings that might be taxing the GPZ onboard audio and creating a perceived need for the SP01 (coincidentally) among others who also use his settings.

I don't know, I'm just going to have to test it myself and see because the way I run my GPZ I have never experienced any distortion at all, so step one is I need to try to replicate this distortion that other people see. Or maybe I have been hearing distortion and have been oblivious to it, in which case maybe I would benefit from an SP01 too.

Can you give me your exact settings where you hear audio distortion so I can try to replicate it whenever I am able to get out into the field next?

[flakmagnet]

35 minutes ago, jasong said:

And the audio smoothing function is more or less a noise filter.

which is why JP consistently has said don't use audio smoothing...

 

[SteelPhase]

45 minutes ago, Chase Goldman said:

That's just semantics.  Pat says in his own post that it "manipulates" the audio.  Whether you call it equalization, filtering, or coloring those are all just imprecise terms for audio manipulation.  

As Jasong previously stated, there is a huge difference between equalization, filtering, coloring and compression. Just ask any decent audio engineer lol. In simple terms, the sP01 squeezes broad signals in the vertical plane so that the rise is more abrupt. That way signals are more noticeable.  

45 minutes ago, phrunt said:

Along with the sP01 having a bypass if I were Pat I'd put another mode on that just boosts the audio with no filters, just so people who dislike any modification of the audio still have a mode they like.

Unfortunately physical space limits what can and can't be included in a product.

[flakmagnet]

The sP01, as it exists right now, is a marked improvement for making signals stand out when I use it with the GPZ. I am sure everyone has differing experiences, but I am very glad I am able to utilize it's advances. It's fascinating to see how much of detecting involves personal choices about what works for us specifically and what does not. 

[Chase Goldman]

52 minutes ago, SteelPhase said:

As Jasong previously stated, there is a huge difference between equalization, filtering, coloring and compression. Just ask any decent audio engineer lol.

My sincerest apologies, just trying to explain why your gizmo is different and superior to the GPZ circuit yet you throw me under the bus to the guy that is questioning the need for the SP01 in the first place for imprecise terminology usage.   That makes sense. 

Won't make that mistake again.

I admit I am just a dumb EE, not a "decent audio engineer".    However, all those terms were being thrown about in the thread without being precisely defined and the terms are imprecise enough to have overlapping contexts (equalization is a type of filtering is it not?)  So please tell me what is the precise and proper term for your filter that "squeezes broad signals in the vertical plane" so I can use the correct terminology without being scolded again. 

Cheers.  

[jasong]

1 hour ago, flakmagnet said:

which is why JP consistently has said don't use audio smoothing...

 

Right. So if one goes to the effort to avoid using smoothing just to have the SP01 do something similar in the end, then one ends up net zero. This is the crux of why I am asking these questions.

1 hour ago, SteelPhase said:

the sP01 squeezes broad signals in the vertical plane so that the rise is more abrupt. That way signals are more noticeable.  

If that is what it's doing then the GPZ lacks the ability to replicate such a thing (other than perhaps changing tone). In that case, I could potentially see the use of the SP01 on the GPZ.

That is what I am asking here. I'm trying to figure out if the SP01 does something not available on the GPZ, or if simply a more judiciously usage of the settings might achieve similar results.

On the SDC for example, no such processing is available so I wouldn't be asking these questions. It's with the GPZ in specific.

[SteelPhase]

3 minutes ago, Chase Goldman said:

My sincerest apologies, just trying to explain why your gizmo is different and superior to the GPZ circuit yet you throw me under the bus to the guy that is questioning the need for the SP01 in the first place for imprecise terminology ussge.   That makes sense. 

I admit I am just a dumb EE, not a "decent audio engineer".    However, all those terms were being thrown about in the thread without being precisely defined and the terms are imprecise enough to have overlapping contexts (equalization is a type of filtering is it not?)  So please tell me what is the precise and proper term for your filter that "squeezies broad signals in the vertical plane" so I can use the correct terminology without being scolded again. 

🤣🤣  No throwing under buses 🤣

Unfortunately when I did the original label I used the word filter which in hindsight was a mistake. Basically its a type of compression but its advantageous to only compress a certain band of frequencies at any one time. Because people run their threshold tones at different frequencies, the optimum band of frequencies to compress will differ, hence the 3 'filter' settings.

'Optimum frequency band' was too big to put on label 🤣

[Chase Goldman]

1 hour ago, jasong said:

Equalization is very different from noise filtering which is very different than compression. These things matter. 

Agree in the sense that they matter if they are precisely defined in the context in which they are used.  I did not say "noise filter", for example.  I said filter in the context of "audio filter" which is part of what equalization does but in an active vice passive sense.  Feel free to deflect it all back on me because of my imprecise usage of terms.  Guess its time for me to take some of my own medicine.  I'll leave tge thread so you can pummel my corpse now.  Lol.  Chase out.