cremona grill
Just to touch on the subject of the grill again, here's an excerpt from 'Stereophile' regarding the Cremona -
'Like those of the Amati and Guarneri speakers, the Cremona's "grille" is a series of cords fastened to top and bottom plates. Insert the bottom plate into the base of the front baffle, stretch the cords, and insert the top plate into the top of the baffle. Ecco! You have a sonically transparent grille.'
Hope this helps some of you who inquired about it.
Just to touch on the subject of the grill again, here's an excerpt from 'Stereophile' regarding the Cremona -
'Like those of the Amati and Guarneri speakers, the Cremona's "grille" is a series of cords fastened to top and bottom plates. Insert the bottom plate into the base of the front baffle, stretch the cords, and insert the top plate into the top of the baffle. Ecco! You have a sonically transparent grille.'
Hope this helps some of you who inquired about it.
fgroen said:
hello and good year
I am well the originator of the crossover project, and the dimentions of cases. Angelilo my friend French was éxécutant it of the cabinet work, it is a painter carrosier, that helps
. The wire used for the mask fabrics is elastic wire with hat. it is dismountable cavity by simple clip metal. The crossover and hybrid, i.e.// on the low registers and series on the medium acute. Listenings one were carried out with people having of truth crémona. they one were very surprised result seeing very very agreeably surprised Aldo
I have built a similar system and at the time I was finished the sonus Faber hit the market.
my set is using a custom built Podszus Görlich 13 cm VK and D2905s capable of incredible power surges.
My system uses a KEF 139B as 'passive' radiator, but filtered in order to dampen the excursions above the bass frequencies it should be doubling for BR. cabinets consist of a very thick laminated MDF with Acrylic side panel.
The tweeter is phase aligned (by ear, a very lenghty process but worthwile).
The crossover I am using is a coil for the 13 cm Vk with a zobel sucking out a tiny peak, and just a coil in parallel for the tweeter with a level attanuator built up from a couple of vintage Allen Bradly resistors.
A passive radiator needs to be approx. twice the size of the active cone yet needs to have almost the same compliance. As the 139B has a large surface area it is an obvious choice....the extremas I saw had the KEFs on the back protected by a plate on which the resistors were mounted.
my set is using a custom built Podszus Görlich 13 cm VK and D2905s capable of incredible power surges.
My system uses a KEF 139B as 'passive' radiator, but filtered in order to dampen the excursions above the bass frequencies it should be doubling for BR. cabinets consist of a very thick laminated MDF with Acrylic side panel.
The tweeter is phase aligned (by ear, a very lenghty process but worthwile).
The crossover I am using is a coil for the 13 cm Vk with a zobel sucking out a tiny peak, and just a coil in parallel for the tweeter with a level attanuator built up from a couple of vintage Allen Bradly resistors.
A passive radiator needs to be approx. twice the size of the active cone yet needs to have almost the same compliance. As the 139B has a large surface area it is an obvious choice....the extremas I saw had the KEFs on the back protected by a plate on which the resistors were mounted.
the system has similarities to ensemble, as they also used Podszus Görlich units and made an attempt to minimize the phase shift of the tweeter.
The starting point for using the 13cm Vollkonus Unit was indeed hearing an ensemble kit using the cheaper regular chassis way back when...
The big difference with ensemble is that they over filtered the poor units, which makes them squeaky in the midrange and the overall stage depth and height are affected
The sound is very very musical, analytical and very quick yet not tiring. Of course is huge orchestral work not their forte per se, yet even f.e. Mahlers synfony der 1000 (conducted by kubelik, recorded in one session in the goold old days) comes across with enough ooomph.
The housing, filters and dampening were ear tuned and then checked by measurements where appliccable (and found to posess a linear freq response as well as having a gradually rising impedance indicating proper phase beviour )
Although the -3db freq will be somewhere around 50-60 Hz they transmit enough of the contours of the lowest bass registers due to the speed of the cones.
Sadly did I have to get the Podszus units fitted with a new surround as the foam was finished, but the trade off of the foam surround (not quite airtight) has now been compensated by rubber surrounds luckily without a audible impact on the overall performance(as I was a bit apprehensive about that).
The starting point for using the 13cm Vollkonus Unit was indeed hearing an ensemble kit using the cheaper regular chassis way back when...
The big difference with ensemble is that they over filtered the poor units, which makes them squeaky in the midrange and the overall stage depth and height are affected
The sound is very very musical, analytical and very quick yet not tiring. Of course is huge orchestral work not their forte per se, yet even f.e. Mahlers synfony der 1000 (conducted by kubelik, recorded in one session in the goold old days) comes across with enough ooomph.
The housing, filters and dampening were ear tuned and then checked by measurements where appliccable (and found to posess a linear freq response as well as having a gradually rising impedance indicating proper phase beviour
)Although the -3db freq will be somewhere around 50-60 Hz they transmit enough of the contours of the lowest bass registers due to the speed of the cones.
Sadly did I have to get the Podszus units fitted with a new surround as the foam was finished, but the trade off of the foam surround (not quite airtight) has now been compensated by rubber surrounds luckily without a audible impact on the overall performance(as I was a bit apprehensive about that).
Running a signal thru a coil to the slave would turn it into a standard 2.5 way speaker. The volume of the box would need to be increased a lot.
I think that the series resistor is 15ohm to the T330D, not sure that is standard though but I know a person that modified his Extremas and used 15ohm.
/Peter
I think that the series resistor is 15ohm to the T330D, not sure that is standard though but I know a person that modified his Extremas and used 15ohm.
/Peter
Are you thinking of Ascolta Brenin with T&P mid + tweeter and SS 8" + 10" bass units? That tuning happened by accident and ended up that way, the designer didn't really know what he was doing but he like dthe result. Never listened to it enough to get a grip on the bass performance but I know it went deep. The 10" had a 10mH coil if memory serves me.
/Peter
Never listened to it enough to get a grip on the bass performance but I know it went deep. The 10" had a 10mH coil if memory serves me./Peter
Yes I was. I have not heard this particular speaker eather.
But it is interesting to think of the back firing unit as a slave, and then add a filtered signal to the voice coil (instead of just another woofer) - what would be the pros and cons ?
Anyway if the originator of this thread is building a copy, then maybe he could experiment a bit.
But it is interesting to think of the back firing unit as a slave, and then add a filtered signal to the voice coil (instead of just another woofer) - what would be the pros and cons ?
Anyway if the originator of this thread is building a copy, then maybe he could experiment a bit.
I would stay away from any amp connected to the passive radiator, as this indeed would warrant a much bigger enclosure for it to properly function.
What I could see as an interesting alternative is a computer controlled active filter, a little mike to capture the signal from the front speaker (or even in line, but yuk, that puts more electronics in the signal path
) and to guide the feedback level of the not-so-passive-anymore rear side.
A bit of adaptive active sound cancellation so to speak, anyone know of any good open source algorythms for that BTW?
What I could see as an interesting alternative is a computer controlled active filter, a little mike to capture the signal from the front speaker (or even in line, but yuk, that puts more electronics in the signal path
) and to guide the feedback level of the not-so-passive-anymore rear side.A bit of adaptive active sound cancellation so to speak, anyone know of any good open source algorythms for that BTW?
gm70 said:
Yes, and???
Back on topic: how are the plans evolving regarding that build?
By the way: Troels Gravesen posted a page of a very nice version of his Ekta's (also Scan-speak driver line-up) built by a Swedish guy. See link here
Looks like a very good starting point..
I presume that you're not a beginning wood worker, otherwise this might be a possible source of frustration...
I thought the aim was not to discuss woodwork (whcih indeed looks very elaborate ) but the sonics...
This last speaker looks gorgeous but has nothing to do with the concept of the sonus faber extrema and its peers....
three way, no passive radiator, it could not be further away from a studio monitor like speaker IMHO.....
Without a look at the filter used in the last example my assumption is that the listening angle would be way over the head of the listener.
) but the sonics...This last speaker looks gorgeous but has nothing to do with the concept of the sonus faber extrema and its peers....
three way, no passive radiator, it could not be further away from a studio monitor like speaker IMHO.....
Without a look at the filter used in the last example my assumption is that the listening angle would be way over the head of the listener.
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