[Joshua_j]

Hi Everyone,
I am about to embark on a new journey with my ESS AMT 2 speakers. The passive radiators need to be redone as I noticed that they are sagging……
So, I have been looking around and seeing a lot of stuff on the site about replacing the active driver (the woofer) because let's face it…… the tweeter is awesome but the woofer is crap. So I got to thinking about replacing both and don't really know if there has been a consensus as to what would be a better matched woofer to the speed of the heil, and if i replace the woofer, how do i then match the passive radiator to it….
So, I notice there seem to be 2 kinds of passive radiators, one that has a spider/frame but no magnet… and one that is just a panel…. and I guess there is something to weight it down as well…..
Any help would be appreciated… thank you….
Joshua

[JohnR]

The main factor that determines what the PR "does" is its area and the moving mass. I don't think flat vs cone makes much difference, except that flat ones are easier to make heavier (use thicker material). You would need to use a box modeling program such as Unibox, entering the woofer and PR parameters and the box volume and use that to determine the required moving mass.

FYI this topic is probably better suited to The Lab or Enclosures.

[pjchappy]

Put this here instead of enclosures, as I thought (potential) further technical explanations would be interesting.


Paul

[Joshua_j]

I am sorry if I broke any rules. Since I am not an expert and fairly new to repairing things on my own,  I put the question in the new persons area.
I appreciate the response as well, but I need to ask, if there is no difference between cones and flat….. why wouldn't they all be flat? it must be so much cheaper to produce. Do you think the difference could be in the transient response or something like that? If I change the original woofer, do I need to change the passive radiator as well?

Joshua

[sreten]

Hi,

Cones have two suspensions, flat only has the one.
Its easy to make cone PR's the same way as drivers.



rgds, sreten.

[Joshua_j]

sreten,
I appreciate the reply. As a complete novice I did realize that there is a difference between the two types which you pointed out as well, hence my question. What is the difference in sound.... or responsiveness.... or longevity...... or absolutley nothing..... and if there is truly no difference why would anyone bo to the expense of making framed radiator rather than just one without.....
I went to the site that the other person had recommended and saw the winbox program..... but to a novice it is a bit complex.... I would just like to get the best sound from the speaker by giving it a better/faster 10" woofer.... but i think that I have to address the sagging passive radiator in the back as well... so if i change the woofer then i think i will have to change the passive radiator as well....
so then i go into thinking about the differences between the passicve radiators because the winbox does not address that as far as I can tell. It just tells you that what size or the weight that needs to be added.....
I ahvent really found info on the differences between the types of passive radiators.....
Joshua

[JohnR]

I went to the site that the other person had recommended and saw the winbox program..... but to a novice it is a bit complex.... I would just like to get the best sound from the speaker by giving it a better/faster 10" woofer.... but i think that I have to address the sagging passive radiator in the back as well... so if i change the woofer then i think i will have to change the passive radiator as well....

If you replace the woofer and PR, they will make sound. Whether or not they will sound their best is something that can only be determined by modeling with the parameters as suggested above. Is there a specific woofer that you are looking at that is recommended for replacement? Perhaps we can try modeling that for you.

[sreten]

Hi,

If this is the arrangement is question changing the driver is not a good idea.

It may be possible to make the low bass somewhat "faster" by detuning the
PR, that is by adding further mass to it, but you are on your own, as you
would be by using a different driver (that should need crossover modifications).

rgds, sreten.

[BobM]

Judging from that picture I can only surmise that it would be damn hard, if not impossible, to mate a driver of that size (with an accompanying "slowness") to a ribbon tweeter (with an accompanying "quickness") and keep some semblance of cohesiveness across the covered audio bandwidth.

[Joshua_j]

Hi,

If this is the arrangement is question changing the driver is not a good idea.

It may be possible to make the low bass somewhat "faster" by detuning the
PR, that is by adding further mass to it, but you are on your own, as you
would be by using a different driver (that should need crossover modifications).

rgds, sreten.

I think that the ESS AMT with the big heil drivers are pretty talked about both here and other places but in all honesty i have not seen a discussion about the replacement of the passive radiator or thoughts on differences between the radiators. This model is not the AMT 1 which has a 12 inch wofer and passive, it is the AMT 2, and it has a ten inch woofer with a ten inch passive radiator………
It still is much slower than the tweeter, but for vocals and sax and other horns i cannot think of a better speaker that I have heard, which is limited to be honest (sonus faber, vienna acoustics, b&w, and some others).
My speakers that I use are Dali Euphonia- MS5's for fronts, CS4 matching center and RS3 rears for a 5.1… the speakers that I play with and have made some projects out of are:  AMT 3 rock monitors, AMT monitors, and these AMT 2's. So I have been doing a lot of reading here and on other sites, and would like to improve on the sound so this is why I am asking (I also have a secret project brewing… i recently purchased the AMT TOWER as a fixer upper project….it has rockfort fosgate wofers in place of the original drivers and I am going to replace them….thus started this quest)
the recommended replacement passive:
http://www.simplyspeakers.com/ess-speaker-passive-radiator-repair-kit-pask-10.html
te recommended replacement driver:
http://www.speakerrepair.com/mm5/merchant.mvc?Screen=PROD&Store_Code=genem&Product_Code=1040SF&Category_Code=
Joshua