PR10 help

[bldozier]

thanks,
from what i understand the Passives server just as port,
could anyone help me understand, this.
and how it applies to the Lancer

I have a project coming up,
and have a few extra passive i wanted to use (2)
per cabinet in line with an LE10 in the middle
le10/pr10/175DHL & le30,

would i be ok using 2 passives per cabinet w/ that le10
thanks

[Robh3606]

What condition are the surrounds in?? If they are yellow and not refoamed they are going to be stiff. Just use a port or go looking the older JBL enclosure manual for box volume although JBL only used 1 per speaker.

[bldozier]

What condition are the surrounds in?? If they are yellow and not refoamed they are going to be stiff. Just use a port or go looking the older JBL enclosure manual for box volume although JBL only used 1 per speaker.

its for a rear channel surround backup,

24x30xD

so is two pr10s per box ok, how do they effect volume.
i was stating from what i had read they just ac as ports.

i would really like to use up some stuff i have so looking to use
four total.

[Robh3606]

Hello bldozier

If you look through the literature JBL recommends 32 Hz box tuning for the Le-10A. The passive radiator was only used in the box volume range from 1.1-3.0 cubic ft after that it switched over to a reflex port. I assume your are not sure how they work so yes they are an alternative to the port and they used different disks of different materials to add mass if needed, so you could put on 2 hardwood disks or a hardwood disk and a metal disk as an example to get the fb " BOX TUNING " you want.

The problem as i see it is there is no PR-10 info on the site so you would have experiment to figure out if you need to add mass to the PR. All you would have to do is run an impedance sweep to see where your fb is. Ideally it would be too high so to lower fb you would add disks as needed.

fb on the sweep is the lowest reading.

As far as using 2 you would have to figure it out but keep in mind you don't want your box to get too big over 5 cubic ft

Take a look through the enclosure plans on the site. 1960's Enclosure Guide and the one linked there is a lot of info in there. Look at Giskards added spread sheets as well.

Good luck!


http://www.lansingheritage.org/html/jbl/plans/1970s-kit.htm

Rob:)