Threaded Inserts (Steel) - TONE A/B TEST

[ghoulbug]

Finally! Thanks for the clips. Now I get to have a proper listen. It's funny how so much discussion has been made about the bridge swap, when the proper clips hadn't even been uploaded yet. Is everyone just taking your observations as given?

Anyways, I'm glad I requested some slap tracks, because the tonal differences are way clearer on them!
The decay is shorter on the HMB, indeed, but it's also interesting how your attacks on the stock bridge seem relatively weaker. Did you make sure to maintain the same technique after swapping bridges?

Tonally, the HMB seems to be punchier, with more bottom end and surprisingly, more high end as well!

I can't wait for the next test: High mass bridge that transforms into brass, threaded inserts, stainless steel jumbo frets, vintage-size tuners, chrome pickup covers, steel neck reinforcement rods, and more, all at the same time!

 

[johnk_10]

i agree about the point of no returns regarding the pressure of the coupling and Tusec's head gasket/compression example is an excellent one, as well as his comment about playing technique skewing the test results, but i personally don't think that it's the 'pressure', but has to do more with the steel inserts having more mass/diameter, transferring more vibration to the body's neck pocket end grain that would yield different resonance results than the standard wood/sheet metal screws.

 

[stingray69]

How is it that you eliminated the variable of your picking technique?

When you say there's a stronger fundamental, couldn't that just mean that you picked a little harder? I mean, you will admit that you wanted the threaded inserts to sound better, won't you? And couldn't this have influenced how you played? In other words, isn't it possible that you put your thumb on the scales a little bit to get the result you wanted, maybe even without realizing it?

I'll bet I could perform this same experiment and prove that wood screws sound stronger, enhanced, more focused, etc..

The technical reason I'm skeptical of threaded inserts is that I'm pretty sure the relationship between pressure and sound transmission in a neck joint looks like a threshold rather than a gradient. In other words, once you've reached a pressure that's adequate to give good coupling, you don't get any appreciable improvement by going further. The basic assumption of those who advocate threaded inserts seems to be that more pressure improves coupling, but I don't think that's correct. To me, threaded inserts are like trying to get more compression out of your engine by cranking the head bolts another turn. It doesn't work that way.

BTW, a great way to see how little your tone depends on high pressure in the neck joint is to take your bass and back off on the neck screws while repeatedly playing a note -- not to the point where it's sloppy loose or anything but enough to where the pressure in the joint has been significantly lessened. You'll find that it makes virtually no difference. That's because the threshold pressure for effective coupling is much lower than even what wood screws provide when loosened somewhat.

At the risk of sounding argumentative, I honestly am not following the car analogy - honestly. I really do see it as an unrelated concept. Now if you were trying to improve & measure the mechanical transfer of vibrations & resonance to the bottom of the engine block by rapping on the bolts from the top with a wrench, I'd think you'd want to crank those bolts down as tight as possible.

I really do have zero interest in selling, persuading or otherwise, the use of threaded inserts or high mass bridges. I played all the soundclips as evenly as possible - hard to do with the slap stuff, but easier to manage with the fingerstyle tracks. The notes I chose to run the spectrum analyzer on were deliberately chosen because they were of the closest volumes. I'm not sure that added harmonic complexities could be "fudged" into a waveform by simply playing harder. I would think that whatever harmonic content you start with is what you would end up with - only louder via playing harder. Not sure one could even "fake" those extra overtones into the waveform if they tried.

I cannot stress enough how little I care about whether anyone wants to try these things on their own instruments. I am simply laying out in waveforms and soundclips what changes happened when I used them, as accurately as I could capture them. It certainly doesn't pay very well to spend my time doing these tests, LOL. But really, I can appreciate some of your arguments but at the same time - they're kind of wasted on me because I am not trying to say any of this stuff makes any instrument "better", but certainly a little different from where they started. As I said throughout this thread, my only desire is to show what changed as best I could and maybe we could have a more solid idea of what these things are potentially doing to the tone of our instruments.

 

[stingray69]

Finally! Thanks for the clips. Now I get to have a proper listen. It's funny how so much discussion has been made about the bridge swap, when the proper clips hadn't even been uploaded yet. Is everyone just taking your observations as given?

Anyways, I'm glad I requested some slap tracks, because the tonal differences are way clearer on them!
The decay is shorter on the HMB, indeed, but it's also interesting how your attacks on the stock bridge seem relatively weaker. Did you make sure to maintain the same technique after swapping bridges?

Tonally, the HMB seems to be punchier, with more bottom end and surprisingly, more high end as well!

I can't wait for the next test: High mass bridge that transforms into brass, threaded inserts, stainless steel jumbo frets, vintage-size tuners, chrome pickup covers, steel neck reinforcement rods, and more, all at the same time!

I did try my best to maintain the same volume & technique on the slap tracks, well all the tracks actually.

As far as that kind of extended testing, I'm not a glutton for that kind of punishment, LOL. Stay tuned for my next thread - which straplocks are best for metal.

 

[selowitch]

The takeaway from all this should include one clear benefit to threaded inserts unrelated to their significant-but-not-earth-shattering effect on the sound of a bass: i.e., the act of screwing and unscrewing the neck bolts no long wears away at the surrounding wood.

 

[stingray69]

The takeaway from all this should include one clear benefit to threaded inserts unrelated to their significant-but-not-earth-shattering effect on the sound of a bass: i.e., the act of screwing and unscrewing the neck bolts no long wears away at the surrounding wood.

True - I also understand that some people like to utilize them when flying a lot. Easier carry-on of the complete instrument rather than risking being sent to who-knows-where by mistake.

 

[selowitch]

I wonder if any mass-produced guitars or basses come with threaded inserts standard? It seems like a pretty good thing to do (although because installing them requires skill and a drill press it does add some cost, and since it's invisible most of the time, it's hard for the average buyer to perceive the added value).

 

[stingray69]

I wonder if any mass-produced guitars or basses come with threaded inserts standard? It seems like a pretty good thing to do (although because installing them requires skill and a drill press it does add some cost, and since it's invisible most of the time, it's hard for the average buyer to perceive the added value).

It would be quite a bit more time consuming to attach necks that way.

When I was searching around looking for general information on threaded inserts, I saw that US Masters Basses uses them as a standard on all basses they do. That's about the closest thing I've seen to a mass produced, every bass scenario. Celinder has used them - don't know about all models or not. I saw that Modulus neck kits come with threaded inserts as the attachment mechanism - not sure about every single neck kit they offer though.

I also stumbled across these forums that had links to a lot of small, high end luthiers who use them, but that's about all I am aware of:

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[Invalid or Expired Link Removed]

 

[steve_rolfeca]

Interesting sidenote: I have an Ibanez ATK 305 with a broad dead spot from around b to d. I first noticed it on the first string, but it affects the same pitches on the second string as well.

After the normal fixes didn't help, I decided to install threaded inserts. I got the same changes in tone that the OP reported in this thread, including a mild increase in sustain.

...but the dead spot is still there, in exactly the same proportions.

I'm calling an exorcist, first thing Monday!

 

[stingray69]

Interesting sidenote: I have an Ibanez ATK 305 with a broad dead spot from around b to d. I first noticed it on the first string, but it affects the same pitches on the second string as well.

After the normal fixes didn't help, I decided to install threaded inserts. I got the same changes in tone that the OP reported in this thread, including a mild increase in sustain.

...but the dead spot is still there, in exactly the same proportions.

I'm calling an exorcist, first thing Monday!

Sorry to hear about the dead spots you're experiencing on your ATK. That does seem like a rather broad area for a dead spot. Whether or not threaded inserts help with dead spot removal, I cannot say. I haven't read much about it on the internet (lack of discussion). I recall mention in the thread that at least one luthier has a belief that threaded inserts can help minimize or perhaps relieve some dead spots. I guess it comes down to a per-case basis, as no two dead spot scenarios are exactly the same in regards to affected area, the amount of note dampening occurring, etc. I suppose if the spot is rather large, it might be too much for the relatively low mass of inserts in the neck heel to overcome.

Thanks for sharing the very interesting & useful info - and I appreciate your validation of the tighter coupling effects that you experienced as well. If anyone has had success (or not) removing dead spots via threaded inserts, either intentionally (as a goal) or as a secondary byproduct of, please drop a line in the thread. I'd sure like to hear more about it.