Originally Posted by
Ian Mackenzie
Hi Scott,
Got ya.
Just looking at your recent posts. What drivers are you currently using?
It seems you have tried the stock M2 drivers and moved on. I haven’t personally set my M2 horns up yet as l am buried in some other work right now. You seemed stuck. But l note that due to the wide dispersion on the horn you “may “ need to globally attenuate the horn response down overall by about 1.5 db or more ref the 2216nd. Or taper the response down to suite your conditions. This may defy convention.
Why?
Due to the very wide power response of this particular wave guide the on actual on axis response while useful for crossover design is not necessary appropriate for listening in a domestic situation where you have six flat un treated surfaces.
Trust your ears not the measurements because your ears are hearing the whole room. Not just the direct on axis response if that makes sense. The D2 driver is possibly more surgical and analytical than what your used to and that is why l posted about analogue EQ. DSP EQ can also cold, analytical or sterile and that is also part of the story. Not really appropriate in the hifi world. So you might be having difficulty acclimatise to the presentation.
Back to the network what 4313 alluded to was a network that allows you to manually adjust an L pad back in the 2-3 khertz area just like the 4430 crossover schematic. It also has a HF brilliance LPad. These L pads enable easy adjustment so you can make adjustments and listen. That is the key.
It’s a very simple network that you can play with. It won’t be technically dead flat. But that l don’t feel is what’s important in your space at the moment.
Trust your ears not your on axis measurements at the moment. Ruler flat response on paper is the icing on the cake. But not what’s in the cake. You need to get the mix right. If you look at the M2 overall EQ JBL significantly doctored the 2216 bottom end to give the presentation balance. It’s like a see saw. Too much mids and highs means your ears need to turn up the bass tone control to make it sound right. First world problem.
The whole deal on it must be flat goes right out the window because your ears are receiving the total sound power and they are saying it’s way too hot. Simply dial back the treble and dial up the bass like a tone control so to speak. Don’t be locked into the rigid regime of obtaining a ruler flat response. That’s where perhaps the confusion is.
I hope this brings you some insight.
Ian
Edit Below is Robert H M2 passive network for the 476Mg driver. It is close enough for any conventional JBL driver. If you have a 16 ohm drive simply put a 20R resister in parallel with the drive and the network won't know the difference.
I have added 3 Lpads labelled in the attached schematic.
These L pads allow independent adjustment of 3 hertz Presence, 10K hertz brightness, and overall Horn level.
Technically an 8 Ohm L pad can be wired up for an 8 ohm trimmer or a 33 ohm trimmer as it has two independent wire wound tracks.
This embodiment will enable on the fly adjustments I mentioned above so you can listen and tweak just the way Greg Timbers does.
As I said earlier the ruler flat stuff is really just finessing the optimisation once you have a ball park listenable system which is the whole idea of using classy drivers.
Notice I actually made the effort to upload nice clean pdfs...LOL. Enjoy your weekend where ever you are.