^^^ Got it
Well, i posted this in another thread, i guess i can put it here too:
"Let’s take it from the top.
In Winisd the "ported" option looks good for sound/FR and that is what Winisd is for (Not TR).
Both ported and PR
have similar pros and cons, they flatten the FR curve, less peaky up top and more effective around tune. And they drop of faster below tune than a sealed would, because of phase shift between the driver and port/PR
So used as VNF, a ported and PR
behave similar, and the fact that the active driver moves the least around tune is irrelevant, because that is exactly where the port/PR
is most effective, adding to sound/FR/SPL.
Here is a close mic measurement of the JBL/PR
in REW, one on the JBL driver(black) and the other on the PR
(yellow). This looks like it should for a ported/PR
. This is NO EQ, so a flat signal(sealed box for comparison is red).
And here is how it looks for FR after EQ. This is from the MLP with JBL/PR
placed VNF. I had to use less EQ on the JBL/PR
because of the things mentioned above, and had no problem integrating the JBL/PR
(blue)with the rest of my subs, as can be seen in the black curve, extension well below 10hz.
That was for FR/ sound.
Let’s move to the TR "sideeffect bonus" of this config.
So, putting the PR
option into Winidsp it seems to work not as good for TR.
Here is exursion on the JBL, sealed vs PR
This is typical behavior when using ported/PR
. Clearly not as linear as sealed.
(Sorry for the weak blue colour)
And here is exursion on the SLAPS. Very peaky around tune, and not exactly linear.
And here is SPL on sealed vs PR
looks flatter, but drops faster below tune.
So in the Viberry thread i showed what happened when i put the sensor ON the cone of the different subs. These aren’t technically mm excursion, but it meaures how much the cone moves, so it is a good indicator of it.
These are all with NO EQ, so a flat signal.
Just for reference, here is one SI18Mk1 sealed box. Note dip down low! This dip has shown up on everybodys Viberry AND VS measurements to date, so don’t read to much into it.
Here is the JBL cone. Same dip down low, and as expected a dip around tune.
And here is where things differ from Winisd, excursion of the PR
. It is not NEARLY as peaky as on paper, however same dip down low, as expected, but for TR i would call this a pretty ok rising house curve.
And guess what: this also mimics how it feels
And here are a couple of Viberry measurement playing real content, San Andreas:
I think it looks pretty ok, and if the dB scale to the left is any indication, i would say both intensity and extension works pretty good
To say i am happy with it is a understatement
Using a PR
BOSS solution makes the FR and TR kind of "locked" together. But you still have DSP control. Only when adjusting EQ for FR it also affects TR and visa versa. This also include delay/phase.
So there is three ways of doing this.
1. EQ for FR and let TR be whatever the result is.
2. EQ for TR and let FR be whatever the result is.
3. Make a compromise of both.
Depending on what other TR devices, VNF, NF and FF’s you have, these could all be viable options.
I went for option 1 and the resulting TR was great, so no further action was required
And IF you feel the FR is great, but TR is a bit much (what blasphemy!!), you could try isolators between VNF box and plattform, to dampen TR while keeping FR.
OR, if TR is great, but VNF are a bit much(even more blasphemy!! ), you could move the VNF’s a couple inches further away from your back. "
We are dealing with the basic differences between sealed and ported/PR
here. If you have a set enclosure volume to go on and unlimited amp & drivers: Go sealed and stuff it with as many drivers and as much amp as you can.
Are you limited in the amp or driver area, use Ported/PR
to get most out of each watt/driver.
Also he is calculating one SLAPS pr
JBL, which is way overkill! This is where the 2JBL’s pr
SLAPS is genious, as suddenly the SLAPS are cheaper pr
JBL than the JBL’s themself, i.e 2JBL1SLAPS is cheaper than 4JBL’s sealed, and requires less amp. And even another bonus is you don’t have to change the box! Just use the sealed one you have, as i did