Hi all,
I finally got the coils and I replaced them.
I really have to agree with tosh, there are so many mistakes made in the original construction of these speakers. Mine also have the same problem with the perforation. Very irritating.
Even one of the original coils was mounted the wrong way!
But the results with the new foil coils are astounding. the sound completeley opened up and the soundstage is much bigger, and there is a lot more depth and clarity.
I can really recommend these tweaks to anybody with these speakers!
Best regards,
Patrick
I finally got the coils and I replaced them.
I really have to agree with tosh, there are so many mistakes made in the original construction of these speakers. Mine also have the same problem with the perforation. Very irritating.
Even one of the original coils was mounted the wrong way!
But the results with the new foil coils are astounding. the sound completeley opened up and the soundstage is much bigger, and there is a lot more depth and clarity.
I can really recommend these tweaks to anybody with these speakers!
Best regards,
Patrick
Hi azagtoth,
Would you send me schematic diagram of 0.3 crossover and the upgrade you perform.
I have changed the woofers with SEAS L REP170.
Now they have deep bass, but a lack in upper bass and very unpleasant bright high mids.
Also, with the pannel disconected, the cones goes to about 3-4 kHz al quite the same SPL.
That is why i want to understand their crossovers.
Thanks
Would you send me schematic diagram of 0.3 crossover and the upgrade you perform.
I have changed the woofers with SEAS L REP170.
Now they have deep bass, but a lack in upper bass and very unpleasant bright high mids.
Also, with the pannel disconected, the cones goes to about 3-4 kHz al quite the same SPL.
That is why i want to understand their crossovers.
Thanks
Hi Petre,
Unfortunately I don't have the schematics drawn out an I don't know all values by heart.
But I can tell you this:
The ESL section has two caps in parallel. One blue 1mF bypass cap and a small black 33mF bipolar cap.
I replaced the 33mF with a Mundorf Mcap and the 1mF with a 1mF Mundorf Supreme oil/silver.
The woofer section has one intertechnik 2,20mH coil glued to the board. I replaced that one with a mundorf copperfoil coil of 2,20mH. This one is from the crc 12 series (54mm in height).
Oh, before I forget: I desoldered the original powercord and replaced it with thick shielded Belden powercable.
Hope this helps a bit, if you need any more info let me know.
Best regards,
Patrick
Unfortunately I don't have the schematics drawn out an I don't know all values by heart.
But I can tell you this:
The ESL section has two caps in parallel. One blue 1mF bypass cap and a small black 33mF bipolar cap.
I replaced the 33mF with a Mundorf Mcap and the 1mF with a 1mF Mundorf Supreme oil/silver.
The woofer section has one intertechnik 2,20mH coil glued to the board. I replaced that one with a mundorf copperfoil coil of 2,20mH. This one is from the crc 12 series (54mm in height).
Oh, before I forget: I desoldered the original powercord and replaced it with thick shielded Belden powercable.
Hope this helps a bit, if you need any more info let me know.
Best regards,
Patrick
What step-up ratio is used with the Final 0.3's?
If they need less than 1KVrms, it should be fairly doable to drive them directly, without a transformer, either using valves or MOSFETs. It's the transformer that's hard to drive, mostly; the panels themselves don't need all that much current.
This would also allow you to make a more configurable active crossover.
If they need less than 1KVrms, it should be fairly doable to drive them directly, without a transformer, either using valves or MOSFETs. It's the transformer that's hard to drive, mostly; the panels themselves don't need all that much current.
This would also allow you to make a more configurable active crossover.
An update...
With Peerless units (833599 - now discontinued) which have almost identical figures for impedance and inductance as the units fitted by Final, a 2nd order crossover consisting of 3.3mH and 70uF provides a steeper roll off above 600Hz and a uniform respose below, along with a much kinder impedance curve. Simulation indicates Final's roll-off being only marginally better than 6dB/8ve and starting at 200Hz (broadly confirmed by measurement) - too low for the panel. The revised circuit sounds smooth and consistent with no obvious transition between bass and panel.
Final appear to made some changes along the way. Serial numbers 200030617 and 200030684 show interesting differences. These include (on 200030617) a much thicker and heavier base to the bass enclosure, better input sockets and a substantially different and much heavier step-up transformer. The large difference in weight is very noticeable.
Tim.
With Peerless units (833599 - now discontinued) which have almost identical figures for impedance and inductance as the units fitted by Final, a 2nd order crossover consisting of 3.3mH and 70uF provides a steeper roll off above 600Hz and a uniform respose below, along with a much kinder impedance curve. Simulation indicates Final's roll-off being only marginally better than 6dB/8ve and starting at 200Hz (broadly confirmed by measurement) - too low for the panel. The revised circuit sounds smooth and consistent with no obvious transition between bass and panel.
Final appear to made some changes along the way. Serial numbers 200030617 and 200030684 show interesting differences. These include (on 200030617) a much thicker and heavier base to the bass enclosure, better input sockets and a substantially different and much heavier step-up transformer. The large difference in weight is very noticeable.
Tim.
Will the same mods work with the original woofer...?
Hi Tim,
Are the impedence/inductance specs for the Peerless unit close enough to the original unit for us to feel comfortable applying your mods to the original unit? (It's mainly the inductor value change from 2.2mH to 3.3mH I want to be confident about).
Mine feature the Taiwanese woofer (anodised dust cap) and the later panel - so the same as the pair you upgraded.
And what value did you finally settle on for the resistor to ground in the bass section of the crossover? Did you stick with 1.25ohms? Did the simulation you conducted indicate a better value?
Hi Tim,
Are the impedence/inductance specs for the Peerless unit close enough to the original unit for us to feel comfortable applying your mods to the original unit? (It's mainly the inductor value change from 2.2mH to 3.3mH I want to be confident about).
Mine feature the Taiwanese woofer (anodised dust cap) and the later panel - so the same as the pair you upgraded.
And what value did you finally settle on for the resistor to ground in the bass section of the crossover? Did you stick with 1.25ohms? Did the simulation you conducted indicate a better value?
The pair I modified belong to a friend so I'm going purely from memory. The problem with the original pair was a broad suckout in the upper bass leading to a thin sound. As I recall, Final's values for the resistor were off by a wide margin causing the impedance to drop far too low and probably resulted in a large part of the suckout we noticed subjectively and later measured. The customary values for the resistor in such a circuit are usually higher (1.25 times, IIRC) than the drive unit's DC resistance, so if I have interpreted the R/C circuit correctly as a zobel network it should be around 7.5ohms, assuming 6ohms for the drive unit.
I didn't know the parameters of the aluminium unit so I can't say if the the Peerless unit has similar specs. In any case I designed the new network from scratch.
Incidentally, we have since changed to, and settled on, a Scanspeak paper/carbon fibre which is superb, again with a new cross-over design. The blend with the panel is undetectable, due in large part I suspect to the quality of the Scanspeak driver.
Adjusting the voltage to the panels via adjustable AC power supplies has also been a useful fine-tuning device.
I hope some of this is of use.
Tim.
I didn't know the parameters of the aluminium unit so I can't say if the the Peerless unit has similar specs. In any case I designed the new network from scratch.
Incidentally, we have since changed to, and settled on, a Scanspeak paper/carbon fibre which is superb, again with a new cross-over design. The blend with the panel is undetectable, due in large part I suspect to the quality of the Scanspeak driver.
Adjusting the voltage to the panels via adjustable AC power supplies has also been a useful fine-tuning device.
I hope some of this is of use.
Tim.
Lenin21,
I don't recall the inductor value but I will measure it when I visit my friend next week. Fortunately we mounted it externally so that we can swap air core for ferrite core at will. I'll also recalculate the resistor/capacitor values when I have located the specs of the exact Scanspeak drive unit we used.
Tim.
I don't recall the inductor value but I will measure it when I visit my friend next week. Fortunately we mounted it externally so that we can swap air core for ferrite core at will. I'll also recalculate the resistor/capacitor values when I have located the specs of the exact Scanspeak drive unit we used.
Tim.
Further to my last reply, I haven't been able to measure the inductors but the details of the changes I made are as follows.
New bass driver - Scanspeak 18W8545.00
Capacitor - 10uF
Resistor 6.8 Ohms
I recall the inductor value was very close to my calculated value of 2mH. I think I ended up at around 1.85mH after fine tuning by measurement and by ear, so I suggest starting at 2mH and tuning by ear, removing a few turns each time.
I also changed the treble section capacitor from 35uF to 40uF which enabled the use of Russian paper in oil types, 4 * 10uF in parallel (I also used one for the bass section capacitor). These sound a lot better in the treble than the bipolar electrolyic used by Final and there is just enough room to mount them beside the main board in the bass of the unit.
Tim.
New bass driver - Scanspeak 18W8545.00
Capacitor - 10uF
Resistor 6.8 Ohms
I recall the inductor value was very close to my calculated value of 2mH. I think I ended up at around 1.85mH after fine tuning by measurement and by ear, so I suggest starting at 2mH and tuning by ear, removing a few turns each time.
I also changed the treble section capacitor from 35uF to 40uF which enabled the use of Russian paper in oil types, 4 * 10uF in parallel (I also used one for the bass section capacitor). These sound a lot better in the treble than the bipolar electrolyic used by Final and there is just enough room to mount them beside the main board in the bass of the unit.
Tim.
Tim-after reading thid thread a couple of times and thinking i can probably get this pair for 600.00 do you think i should buy em and do the mods? im not rich but i could afford these. i have a luxman m-117 to drive them with. plus id really like to put these polks on the RR tracks behind my house and video it.
Further to my last post, I have now measured the inductors and they are 2.15mH. With the other changes mentioned previously the integration between bass unit and panel is impressively smooth, even when you know where it is (usefully, I have perfect pitch so I can 'zone in' on particular a frequency range). Of course the quality of the Scanspeak's upper bass helps too.
vrusso123 It is up to you. With the mods mentioned they are certainly very good. If it helps I'm a professional musician and my friend who owns the modified pair is a piano tuner. He was so unhappy with them when he bought them that he was going to sell them but since the mods he loves them. I'm always impressed when I hear them but I use modified Quad 63s myself, which I prefer.
vrusso123 It is up to you. With the mods mentioned they are certainly very good. If it helps I'm a professional musician and my friend who owns the modified pair is a piano tuner. He was so unhappy with them when he bought them that he was going to sell them but since the mods he loves them. I'm always impressed when I hear them but I use modified Quad 63s myself, which I prefer.
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