Anyone here upgraded from the 12inch Ferrite to the 12in Alnico drivers? I have had a pair of the ferrites for a few years and I love them. But have had them awhile so thinking about going up a notch.
Can anyone personally attest to the difference after break in?
Can anyone personally attest to the difference after break in?
I'd like to know what your present AN would sound like if you raise Qts to match the Alnico model's spec (Qts ~0.64 if spec sheet right) via either series resistor or series incandescent lamp plus R combo (latter would add some soft compression in hopes to emulate alnico)
Unfortunatelly the 12 and 15 inches Alnico have no bass under 100Hz as can be view easily below:
I have the Classic10Alnico and could change right now for the Lii F15 (in view of the all positive reviews) in a barrel OB or the rec 292L BR box:
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I disagree. Wish I still had the measurements I took before I sent my dsp back. This system has the most real sounding bass I have heard except for systems costing way more money. If we have learned anything about audio equipment its that measurements do not determine how something will sound.
Yes/no in that having had numerous 'FR' AlNiCo and its ferrite ['mud'] motor variants, there will be audible differences once any obvious response anomalies are accounted for with type of amp/output impedance making the most difference, so for me it's ferrite [or better] for < ~300 Hz to get music's 'heart attack fast' [transient perfect response as seen in an impulse test] and AlNiCo for the 'lush' presentation of a large concert hall or smaller venue dedicated to live performances.
The alnico version is spec-ed half as efficient as the ferrite version.
You want to add some resistance to the ferrite motor model to raise Qes (and Qts). Part of that resistance might be a 211-1- incandescent light bulb whose cold R ~0.5 ohm and 15 ohm hot.
You could just try the resistor by itself first to listen to effects. (try an 8 ohm resistor)
Somewhere there's an online calculator to make it easy to see how much resistance is needed. (Bet GM knows)
A filament transformer (with its low voltage winding in series with speaker and 120 winding with a pot) might be used like Decware's Gizmo - that could be fun.
You want to add some resistance to the ferrite motor model to raise Qes (and Qts). Part of that resistance might be a 211-1- incandescent light bulb whose cold R ~0.5 ohm and 15 ohm hot.
You could just try the resistor by itself first to listen to effects. (try an 8 ohm resistor)
Somewhere there's an online calculator to make it easy to see how much resistance is needed. (Bet GM knows)
A filament transformer (with its low voltage winding in series with speaker and 120 winding with a pot) might be used like Decware's Gizmo - that could be fun.
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What cabinet design are you using for your AN 12? Seems the differences with Qts and Vas, etc. might dictate a different design for the Alnico. Lynn Olson made several interesting remarks on Alnico drivers in his enormously long thread here Beyond the Ariel (well worth the read for me at least). This was one of several observations. #14015 "In subjective terms, the Alnico drivers (regardless whether they are Altec, Lowther, Feastrex, or TAD bass drivers) have a distinctive "nickel-core transformer" sound, compared to a transformer with a conventional M6 (silicon steel) core. That's a difference that is meaningful for those of us who play with building our own tube amps from scratch, and have done transformer swaps while subjectively balancing the amplifier."
I have one alnico FR which sounds pretty much like a ferrite - the large potted alnico magnet EV SP12A with chrome frame - it seems to lack that "shimmer" associated with alnico motors. Also, voice coil former made of paper may sound nicer than kapton (?)
FWIW it would be nice to see a Klippel report on the AN alnico 12. For that kind of money one would think a field coil model could be offered.
FWIW it would be nice to see a Klippel report on the AN alnico 12. For that kind of money one would think a field coil model could be offered.
My cabinet is Internal dimensions - 17" wide x 12" deep x 46" tall and a 5.875" port in the front panel with an internal stiffener about half way and insulation stapled to the inside everywhere but the baffle.
Seems like your cabinet is very close to the 5.6 cu ft that David Dicks recommends for the AN12. I have a pair of the same drivers and have tried them both in a sealed 2.5 cu ft and in an open baffle, both set ups were with a crossover at 70Hz for subwoofer duties. A recent move caused me to put the drivers back in their boxes for now but when I move to a suitable space I intend to build them a suitable cabinet. I have considered a "Boffle" style cabinet with matching subwoofers. I suspect the Alnico version with its higher Qts would be well suited for such a design. Never had the chance to hear them with a single ended amp such as yours but I did like them with an EL84 push pull amp.
Did you listen to the results from adding series resistance to make the ferrite motor more equal in strength to that of the alnico motor?
Both the alnico and ferrite motor versions require ludicrous sized reflex to fit T-S reflex alignments.
An incandescent bulb could add some "sponginess" to the resistance. 1 or more with a series resistor could be put in parallel with another resistor. I guess some of the fudge would depend upon the peak power of your amplifier with music.
Here's your Classic 12 with a 7.2 ohm series resistor compared to non modified Alnico Classic 12
Both the alnico and ferrite motor versions require ludicrous sized reflex to fit T-S reflex alignments.
An incandescent bulb could add some "sponginess" to the resistance. 1 or more with a series resistor could be put in parallel with another resistor. I guess some of the fudge would depend upon the peak power of your amplifier with music.
Here's your Classic 12 with a 7.2 ohm series resistor compared to non modified Alnico Classic 12
Attachments
btw, I made a mistake on entering Fs for the Alnico box size calculation, but it doesn't show in the result with such high Vas and low Mms
Back in the day, Gilbert Briggs did mention a 24 cubic foot reflex as having merit 😀
Back in the day, Gilbert Briggs did mention a 24 cubic foot reflex as having merit 😀
I will try it soon. I just got my new volume controllers installed so I am still adjusting to the sound now. Anyone on the fence about TVCs go ahead and get them. Its a significant improvement. Only caveat is if your system is on the bright side you may want to skip them as it will accentuate it. Everything is clearer and more present sounding. I just ordered a replacement genalex 300b tube to replace the one I had a heater fail on. Those tubes have more and tighter bass than the PSvane perforated plate tubes i have now. Should be even better with the volume controls. But I will test the speaker resistance as soon as my system is stable for awhile so I can actually tell what it did as opposed to being confused by other recent changes.
FWIW, minimum size for Altec's similar specs drivers was the ~6.3178 ft^3 [gross] 612 utility cab: http://www.lansingheritage.org/images/altec/plans/1970's-lf-plans/enclosures05.jpg
You're welcome! From the days when Altec's/JBL's 'West Coast Sound' = 3-6 dB [mid] bass [under-damped] boost and considering how popular it was [and around the world still is for many], not nearly as 'evil' in room as T/S theory 'claims'.
This was also before T/S parameters were known so it was build in a whole different way, and that 612 cab, although it sounds very good, is very limited on bass. In modern setting i would use it with a sub. Just like i would do with AN drivers as their bass is definitly lacking for me.
But as always, if you like it...
True, it was designed for the times, so even with a 42-45 Hz tuning it was still ~ -24 dB, so a 'strong'/'prominent'/'thumping' bass was actually a mid bass one that was the norm in prosound until fairly recently.
For a 'fuller', more extended bass, the 620's ~9 ft^3 suffices for most folks.
Agreed, I added subs to my first Altec horn system when they came out with an 18 Hz Fs H.E. 15" optimized for 5-6 ft^3 sealed in '71 and later made dual corner loaded 20 Hz Fs 15" ML-horns/channel tuned ultimately to ~14 Hz, so you're 'preaching to the choir' 😉.
For a 'fuller', more extended bass, the 620's ~9 ft^3 suffices for most folks.
Agreed, I added subs to my first Altec horn system when they came out with an 18 Hz Fs H.E. 15" optimized for 5-6 ft^3 sealed in '71 and later made dual corner loaded 20 Hz Fs 15" ML-horns/channel tuned ultimately to ~14 Hz, so you're 'preaching to the choir' 😉.