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Through curiosity I have been trying some Bluetooth transmitters and headphones lately. Earlier Tx had lag problems, but you can get low latency units now. If Tx and phones are advertised for TV use then they can be okay for detector use.

Price was not much of an indicator of quality, as some of the cheaper units were pretty good, even having active noise cancelling and volume control. One combination provided more volume than needed and good clarity.

Summing up I would say that for very few dollars a very effective match can be achieved, but some units were disappointing and it is difficult to know what will work well and what will not.

Some of the negatives were; not enough volume on both Tx and phones.. poor sound quality..distortion from Tx with loud signals.. lack of sensitivity in Tx with faint signals.

Even the best combination I could put together was not as good as my Quest, although quite a bit cheaper.

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 It seems to me that most of you young fellows must have much better hearing than I do. My audiologist says that I have a profound hearing loss. I wear behind the ear hearing aids, so over the ear headphones are my only option. The WM 12 without headphones doesn't give me enough volume to hear target signals especially if there is any ambient noise. The booster allows me to lower the floor level noise and raise the target signal volume. The wireless headphones are lighter, cooler and more comfortable with good sound quality.

                                                                                                 Norm

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1 hour ago, jasong said:

But the boosters I don't understand since I cannot see a situation where both the volume on the WM12 is insufficient and headphones are not the better option at that point.

I use the SP01 not necessarily for audio boosting, but rather to have more control about target response/ filtering of audio frequencies. This goes beyond to what the Volume control on the GPZ control box is doing. I just hear faint signals/wobbles clearer. 

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I can understand for those who use hearing aids.

What I'm not getting is what exactly these modules do that the onboard GPZ audio processing does not do. 

What is the SP01 filtering? The GPZ is digital so it's not really picking up analog EMI (aside from case interference such as discussed in this thread, which can be eliminated by not operating devices close to the box). The EMI the GPZ picks up is through the coil, and manifests itself also as digital signals which could just as easily be targets like a gold nugget. A filter has no way to tell, at the end of the processing chain.

So if running a 3rd party filter on the GPZ, isn't one running the risk of filtering targets out too?

If so, isn't this counterproductive and antithetical to running the threshold high and using no smoothing as most who I've met who run boosters tend to do?

Why not just turn the threshold down or run in Low Smoothing instead and have one less thing to clip to your harness?

 

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Early in my use of the GPZ there was always the discussion (and there still is) about the Koss headphones supplied with most Minelab detectors.  This 'connection' of the two companies is a long one by some sort of default it seems and Minelab hasn't seen the need to experiment with other sound.  Some stick with the headphones and others abandon their features/lack of features.

I had some noise cancelling headphones made for plane travel use which means they folded and were light.  They required one AAA battery in the headphone cup but that gave them very good volume control with an inline system.  I would take the thin cord and tuck it out of the way.  It didn't need a thick curly cord but it was also not built for real outdoor use.  I went through a couple of them but they worked great.

I could achieve what Simon and JP were talking about which was to run a very low threshold and turn up the volume.  Somewhere over a period of time of depleting my patches where this combination was successful and getting a BZ and now an SP01 I stopped using the noise cancelling phones and have returned to the Koss which have a lifetime warranty.  I've had several pairs fixed and replaced over the years.  My hearing has also lessened.

I bought my SP01 in Australia last year and I was one of the first to also buy their headphones.  They are quite good at keeping outside noise away with very secure headphone cups but they are also a bit snug and my ears are big and sensitive to them.  Simon said he is fussy about certain things and that is the way I am about headphones.  I should use these headphones more but ...

The WM12 has always received my signal just as the WM10 did but I found it more convenient to adjust volume in the wired line (volume control, BZ, SP01) than with the GPZ or 3030.  This seems to work well with Chet's and Lunk's settings also.

The last thought I have for the moment about the audio on the GPZ is something that JP has always said about the GPS on it.  He turns it off because he believes it to be a resource hog.  (I keep mine on so I can find my car!)  Would Minelab create a 'resource hog' of an audio system if they changed things?  I'm not technical enough to know but the board and chip level innovations of today are much greater than even when the GPZ was designed.

Mitchel

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13 hours ago, phrunt said:

It needs plugged in with cables and because your head isn't detachable from your body and the SP01 is chest mounted there's no real need to use bluetooth headphones, may as well have corded ones plugged into the SP01 with the cord neatly fastened to the harness and just use the Bluetooth for wireless direct from the GPZ, or the WM12 if it floats your boat.

That's the point I was trying to make.  Why deal with the headache of two wireless systems especially from chest to ear.

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If it's just about volume boosting then I understand why those with bad hearing use a booster, I still don't understand why people with good hearing swear by them though. What people tell me in the field is that they are enhancing signals, not making them louder, but I've been unable to hear anything that couldn't be replicated for free with the GPZ audio controls so far.

19 hours ago, phrunt said:

For such an expensive detector it really has substandard audio capabilities.  In fact it's audio capabilities are terrible, even if my WM12 worked properly I'd still think it's got poor audio capabilities for it's price.

I don't understand - what specifically should the GPZ have that it doesn't have or what makes what it does have terrible?

The GPZ has volume, volume limit, tone, threshold control, and audio smoothing. With these you can filter EMI and emulate a compressor which seems to me the only things the SP01 could be doing. These control the WM12 remotely. The WM12 seems to just operate as a remote speaker, not a processing unit. Which is IMO the way it should be for a piece of field equipment. A fancier WM12 means they'll charge even more than they already do, and losing or breaking one would break the bank.

I think the WM12 is built physically like a cheap toy and I am not trying to say it's a great piece of equipment, but I honestly don't understand the criticism of the GPZ audio processing. To me, it's the right idea, it just needs more Smoothing control, like a slider and not just 3 settings between 0-low-high. So few actually use Low Smoothing or run lower thresholds along with vol limits and volumes but then are totally willing to use filtering on the SP01, it doesn't make sense to me.

I can definitely see a use for the SP01 on a unit like the SDC which really does lack audio processing control. But on the GPZ, I'm confused.

What I'm curious to know is if the SP01 filtering is doing anything that you can't do for free using the onboard GPZ audio processing controls. And if so, what specifically it's doing which cannot be done with the GPZ controls.

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19 hours ago, jasong said:

I still don't understand why people with good hearing swear by them though

On the GPZ the target volume and threshold volume need to be set/adjusted based on ground conditions and target response in the area you are hunting. I like the additional option of audio boosting without changing any of these parameters. Like a functionally independent volume control without interfering with how the GPZ processes the audio signal based on it's internal volume/threshold setting. Regarding the filtering option, which is a separate topic and not related to the audio boosting function of the SP01, I like the setting "1"  which IMHO makes the target signal  somehow cripser (regardless of GPZ settings). I am sure Nenad can comment about the specific reasons why that is. You are right, for the SDC it is a total game changer. But I, personally, find the filter function useful for the GPZ as well. But everybody is different.

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We seem to have gotten specifically away from the EMI question that Norm originally posted with talk about assisted vs unassisted signal processing.  Here is a thread about THAT which we hear from both of the 'principals' of the B&Z or SP01 talk about their products.  As Gold Catcher said maybe they will join us on this thread as well.

 

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JP said:

The volume control on the Minelab units are very coarse, once you get above certain point they clip, a good booster helps a lot to avoid this.

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