AVS interviews

[rickcraig]

Scott Wilkinson from the AVS forum has done many great interviews. Here's an interesting one...

http://www.avsforum.com/forum/138-avs-forum-podcasts/1618434-new-jbl-speaker-technologies.html

[ligs]

Re: AVS interviews

Interesting!.

Can someone interpret the response curves of JBL M2 in this reference.http://www.jblpro.com/docs/default-s..._april2013.pdf

[Face]

Re: AVS interviews

Interesting!.

Can someone interpret the response curves of JBL M2 in this reference.http://www.jblpro.com/docs/default-s..._april2013.pdf

http://www.synaudcon.com/site/author/pat-brown/ideal-vs-real-directivity/

http://www.linkwitzlab.com/Constant_directivity_louds.htm

http://www.mcsquared.com/speakers1.htm

[ligs]

Re: AVS interviews

I assume JBL graph is trying to show that it has a very wide listening window. However, JBL is talking about power response. How does it differ from the typical frequency response we normally see in this forum?

[rickcraig]

Re: AVS interviews

I assume JBL graph is trying to show that it has a very wide listening window. However, JBL is talking about power response. How does it differ from the typical frequency response we normally see in this forum?

There are different opinions on this. The JBL target curve is based on their extensive research into what listeners prefer in controlled tests. Some builders here probably just look for a smooth on-axis measurement while others are fanatical about constant directivity in the off-axis behavior.

[UGP]

Re: AVS interviews

I assume JBL graph is trying to show that it has a very wide listening window. However, JBL is talking about power response. How does it differ from the typical frequency response we normally see in this forum?

Did you look at the links that Face posted?

[Greggo]

Re: AVS interviews

At the risk of embarrassing myself, I think the JBL graph is supposed to communicate a couple of things:

1) The horizontal, vertical, and total response are very close and consistent... so the takeaway here is that "control" has been achieved, and given the reasonable smoothness of the shape of response, there is no tell tale sign in terms of frequency response "foot print" between the two drivers so the crossover between them is not easy to detect

2) The lower lines are showing the reflected energy that would arrive back at the listener (I am assuming this is of course dependent on "typical room" guestimates) and it shows how this is a very rising response, that when spliced together with the direct response achieves a fairly level response at listening position.

3) Since these two "sets" sum up together fairly well, you have accounted for reflections (even through they are not in perfect time with the direct signal) and not allowed the room to swamp the mid and upper frequencies. Unfortunately for me, this is exactly what happens with my current system in my untreated room, the reflected energy starts to really build up somewhere around 1-2 kHz through maybe 6-8 kHz and things don't sound nearly as good as they did in the showroom when I bought them. My own interpretation is that there are two different schools here, with one attempting to control directivity response via waveguides and then aiming the direct sound in a specific manner to create a stereo image starting in front of the listener, with the other school attempting to account for "typical" room contributions and also accounting for differences between woofer and tweeter in the crossover shaping so that a balance is achieved between the drivers operating independently, the drivers overlapping, and the speaker system overlapping with the room.

This is the official "arm chair quarterback" interpretation.