choose (how?) a fullrange for Peerless 830878 passive radiator

[gecnicolson]

I bought a pair of peerless 3.5" passive radiator , that fullrange I choose? And above all, how do you? I'm reading a lot to enter the DIY world..and I wanted also to ask you.

Do you think the partsexpress parameters are correct?
Because in any simulation (i have a pair of fountek FE85 in a 1.7liter box) but i have no bass response as i imagined. Why?

I read that:

PR must be larger than the active driver about 1.5 - 2
PR is like (similar) bass reflex, so the active driver must have an EBP > 100 and Qtc between 0.25 and 0.5 (correct?)

the active driver must have a high x-max value (correct?)

thank you in advance.
E

Peerless 830878 3-1/2" Passive Radiator

 

[Inductor]

Yes, the PR is similar to the reflex system but with Fountek FE85 FR driver you have only F3~80Hz. You will need a sub/FAST system or other (another FR driver?) for LF. The passive radiator doesn't help very much in that situation.

 

[gecnicolson]

Yes, i want to choose another FR driver..but i don't understand how..

this question are my starting point.
i'm looking for.. but what are the important parameters?
xmax?

 

[GM]

It has a published 29 Hz Fs, but it's Sd is only 50.2 cm^2, so apparently your only option is the 4" Peerless SDS: Tymphany SDS Series 830855 4" Woofer 8 Ohm

GM

edit: Hmm, then again from looking at its specs, a small 'FR' driver with similar Fs, Qts and a tiny Fs might work OK.

 

[hifu]

I happened to see this, two 830983s and a PR, might find it interesting if nothing else.

 

[gecnicolson]

thank you hifu, in this moment i have a FR fountek FE85 in a 1.7 liter box with PR and (with equalization) sound great.
I wanna use a FR with do no need to equalized..and i want to learn how i choose FR in this case..

 

[GM]

I happened to see this, two 830983s and a PR, might find it interesting if nothing else.

Apparently it is just playing whatever note the PR's tuned to, i.e. the proverbial 'one note' bass of just box resonances as opposed to being in sync with the driver.

GM

 

[GM]

i have a FR fountek FE85 in a 1.7 liter box with PR and (with equalization) sound great.

With the Peerless 830878? If so, I have to wonder about its specs because with a published 29 Hz Fs, it's much too low to properly mate up with way higher Fs drivers.

What are your EQ settings?

GM

 

[gecnicolson]

i don't have a chance to measure it in this moment..

but equalization up to +6db on 60hz to reinforcement on lower frequencies..

the box is inefficient. the exursion of the fountek is dangerous ..this speaker don't have power handling up to 12watt.

i'm sure about this..

 

[Inductor]

i don't have a chance to measure it in this moment..

but equalization up to +6db on 60hz to reinforcement on lower frequencies..

the box is inefficient. the exursion of the fountek is dangerous ..this speaker don't have power handling up to 12watt.

i'm sure about this..

Hi,
The Eikona Mk2 to 50Hz w/no eq., 12cm diam./5'' , 50 watts
EIKONA 2, VB = 6.5 L, FB = 39.4 Hz
Jordan Eikona - E J Jordan Designs
http://www.diyaudio.com/forums/full-range/229391-experience-jordan-eikona.html