Cross bar triggers; why always a central piezo?

[docadiddle]

As a first foray into DIY I'm going to convert an old A-drum using a cross bar mounted piezo. My question is, why are piezos always mounted centrally especially when hot spots over the sensor seem to be a common problem? Why not mount it close to the edge in the 6 o'clock position, an area of the head which, certainly in my case, I'd be very unlikely to play. Just curious...

And secondly, could anyone direct me to a clear diagram showing the best way to mount the piezo showing which bits are foam, double sided tape, isolating screws etc. Thanks in advance.

[jpsquared482]

Hi,
The simple answer is that a centrally-mounted trigger enables positional sensing, but only for the modules that support it, of course. If your module does not support positional sensing, there's no good reason to mount it in the center.

[New Tricks]

I mounted mine in the center because that's the way Roland does it They worked perfectly. I thought there might be hot spots but, not really.

The beauty of the DIY build is that you can easily experiment. You can relocate the piezo in just a few minutes and see what it sounds like. Just don't stick it down fully on the first try. Cut a small piece of the paper backing of just to tack it in place. When you are happy, stick it down hard.

I don't have a diagram but I simply made the cross bar from 1" aluminum angle (the foam Quartz brand triggers are appx 1" diameter).

I used simple angle brackets to attach the cross bar to the lug hardware and made my height adjustments by adding extra nuts as spacers between the bar and angle bracket. In my build, the top of the cones were 1/4" above the rim. My mesh heads were pretty thin and, with them installed, there is a very slight bump at the cone. It may not show in a double or triple ply head.

[TheYardbird]

As mentioned above: Positional Sensing. If you don't have a fairly new mid/high end Roland module that supports it, you might aswell go with a side mounted trigger like the Intrigg.

[hemiboy]

Yeah like Yardbird says the center cone crossbar triggers in the case of Roland's high modules have positional sensing. When I built my kit, which Jman really built, honestly, I bought the crossbars center cones on case I ever bought another module that had PS. Now that I am playing 2 box I really don't need them yo be crossbars but they trigger perfectly and who knows maybe z3 box will come out with a downloadable positional sensing upgrade soon!

[allanjohn]

A secondary reason is more even triggering. Think of the trigger getting impulses from around the head. If it's side-mounted, there's some delay between a strike at the other side of the head and the receipt at the trigger. The centrepoint is the shortest distance for impacts.

[hemiboy]

Certainly makes sense , but I haven't personally heard anybody complaining about uneven triggering with quality side mounted internal or external triggers like Intrigg or 2 box having uneven triggering ? I did hear some issues with Roland and Red shots having uneven triggering though

[JmanWord]

For anyone interested, because of how many people seem to mention the "hot spot" with center mounted drum triggering .... I had considered offering a side mount style trigger for my Stealth 2Box drum conversion kits. After testing and comparing over and over, I decided to abandon the side mount style. The center mount triggering was so far superior especially on drums larger than 10 or 12" I wouldn't even consider using side mount style myself. And simply using the Pos 1 or Pos 2 (2Box) curve evens the response out quite nicely of the outer area of the head compared to the center. I've been playing center mount for years and years and am very happy with the results. Log 1 or Log 2 is the name Roland uses for the same curve. Give it a try.... J

[allanjohn]

As Jman says, it is an issue on larger drums. When you hit 14" and 16", you can tell the difference, especially when you hit on the opposite end of the drum and the strikes are detected as much weaker.

[fulrmr(Daniel)]

Not that I don't yield to the wisdom of the more experienced sages hear that I have personally learned much from in my DIY journey and owe any DIY skills that I might possess to...but I have had no problem with side vs center mount with my 2Box...with one exception.....I do believe that having the rim piezo centrally located in my pans yielded better results than near the shell...even with the side mounted head trigger...all the way up to 14" pads. Just my 2 cents.

[triggera]

I can just disagree. I'm using my intriggs on 10",12" and 14" and we have people using intriggs even on kick drums.
From another thread, here at vdrums:

What realy surprised me was how fantastic good the 22" kick was With the intrigg ;-)

You can't just try a sensor you were using in the center and mount it on the side. Also, the cone shaped triggers will generally perform poorly when mounted on the side ...
etc etc
So, like with acoustic drums, where the secret is not in the shell nor in the bearing edge nor ... but in the combination of all the factors. The same goes for triggers.

[allanjohn]

Of course, kick drums are different: There's a much larger impact, concentrated on the same spot (near the centre of the drum) consistently.

[jpsquared482]

It seems side mounted triggers can trigger "inconsistently" because (with larger drums mainly) the strength of the hit detected by the trigger varies with distance from the point of impact of the hit to the trigger. That's basic physics. It's probably not a lot a "big" difference, but noticeable to some with their setups. My guess is that that difference also varies with head tension. If the head is tight, the energy travels from one side of the head to the other much more directly. If the head is loose, the energy diffuses before it reaches the other side.

My suggestion, for those who have large drums and side mounted triggers is to tighten up the mesh and see if that improves the consistency of the strike force detected by the trigger at different points around the head.

[docadiddle]

Thank-you for all your excellent replies. I'm planning to use a 2-box module so no PS I guess but still sounds to be the case that centre is the first thing to try. Am I right in thinking that the 2-box doesn't support rim shots (ie,simultaneous rim and head signals to give a rim shot sound?). With regard to the other part of my question regarding the order of cross bar/sensor plate/glue/double sided tape/piezo/tape/foam, do you know where I can find somewhere which simply explains the best tried and tested arrangement?

Thanks once again, you're all brill!

[triggera]

Sure it does support rimshots. And they have side-mounted triggers in their pads.

[JmanWord]

I can just disagree. I'm using my intriggs on 10",12" and 14" and we have people using intriggs even on kick drums.
From another thread, here at vdrums:

You can't just try a sensor you were using in the center and mount it on the side. Also, the cone shaped triggers will generally perform poorly when mounted on the side ...
etc etc
So, like with acoustic drums, where the secret is not in the shell nor in the bearing edge nor ... but in the combination of all the factors. The same goes for triggers.

Yup, I definitely do respectfully disagree on this one, and I would never just assume switching a center mount design to the side would produce the desired results. Testing multiple piezos, foam densities, foam shapes, etc. I still find the best response via center mount head piezo. As far as 2Box mounting on the side, I won't profess to know all the reasons, but if 2Box wanted to sell in the US even mesh heads were out of the question, let alone a center mount piezo. It is easy to sell triggers outside of the US though even if they look identical to other companies' triggers, not so in the US. .

Anyway, that's my "opinion"

[fulrmr(Daniel)]

You can't just try a sensor you were using in the center and mount it on the side. Also, the cone shaped triggers will generally perform poorly when mounted on the side ...

Hmmm....really? why not? I can't agree with this at all because that's exactly what I did. In my experience....cones(with the same exact trigger assembly) perform very well when mounted near the rim. In fact...when testing the TD-30 they performed equally as well as the center mounted cones(except for PS of course)...and both function very well with the 2Box....I still prefer the center mounted rim piezo though.

....and since the kick was mentioned....I would never use a center mounted trigger for fear the beaters would destroy the assembly long before it's time. But that's just me and what I have observed from others and personal experience.