Dear @audphile1 : I could think that owning the Wilson Sabrina you already know from where came the today design or which are its roots. Any way this is the history:
first that D. Wilson designed his first speaker he was working by several years as recording engineering for different labels ( I own 3-4 different LPs recorded by D.Wilson that when I bougth it I was almost ignorant not only who was D. Wilson but many other audio main subjects. ).
The DW decided to design and manufacture a proffesional small monitor lovely speaker that was named Watt and that was used for many LP recording studios and latter on by audiophiles and had so success with the Watt that when all the people were asking for that Watt speaker but with more extended bass range and DW designed the Puppie ( bass unit ) that had great success too till the Watt Puppie VI. The Sabrina came from there in today version, so very fine " pedigree ".
No problem if you can't be aware of the IMD in the Sabrina even that it's down there and this is not the matters of this post but here the J.Atkinson real time measurements that confirms what I'm saying due its around 350hz woofer crossover frequency. E ven that a truly fine speaker:
" Wilson Audio Specialties Sabrina loudspeaker Measurements | Stereophile.com
In the other side, yes I'm enjoying my " old " whole system that when I bougth the ADS L2030 Proffesional Monitor speakers I was totally ignorant what I bougth but this really special ADS speakers , as your Sabrina, has its own history.
Things are that in those old times ( early 80's ) Telarc Recording LP label ask to ADS to design and build a dedicated monitor according Telarc needs and it comes not the L2030's but a customer design with main speaker and subwoofer that were paired by Threshold big class A amplifiers designed by today N.Pass.
Telarc was happy but they ask for more and ADS introduce to Telarc in the customer design L2030 and the L1530 and theese Proffesional Monitors were the ones used in around 70 pressed Telarc different scores.
I born and live in México city and at the USA border in Laredo,TX an audio big store saler offered me the ADS L2030 that was only in exibition but only in passive way so I never heard and I bougth it because impressed me with out its big grille and bougth it: only subjectivity and ignorant of the L2030.
Well this ADS speaker is a true full range one with -5db at 16hz to 30khz. Its driver units are unique even for today top standards:
with two 14" PAPER pulp woofers ( as the today Evolution subs. Paper pulp has the best quality performance material that it's not outperformed by today other materialsssssss reproducing bass range: period. ) wired in parallel in different and closed " house " ( the overall speaker design is not only sealed one but each driver acoustic suspension design.).
Been a Professional Monitor the L2030 was designed with two midrange options: Line source and Point source along the single Tweeter. In Line Source mode the speakers runs the midrange through four midrange silk domes where 3 are the auxiliar drivers and one a very special main midrange that comes with bigger magnet and along the silk dome special Tweeter whe in Point Source mode runs only the main midrange with the tweeter where both driver are not coaxil but extremely close in between.
The main midrange silk dome and the silk dome tweeter where made expressily for ADS in Germany and both drivers are unique. The 1" silk dome has 24K Gauss as its motor ¡ ¡ ¡ The linearity true linearity of these two drivers is just exeptional and almost free of distortions.
My L2030 are up graded by me in this way:
"" These L 2030 was designed by Mike Kelly ( Aerial speakers ) and till today it match all my priorities.
It is " heavy " tweaked to do that: first it has " three hands " ( internally ) of a insulation/antivibrational treatment ( like a white paint. I can't remember the ingredients. ) from Acoustical Magic Company ( it works marvelous ) inside all the box ( a big one box: 58-5/8" ( H ) x 27-1/4" (W) x 13-1/8" (D) ).
It is internally hard wired with Silver Oval by Analysis Plus cable and KCAG by Kimber Kable.
I take out the crossover ( now is external ) and change all the parts: resistors ( Powertron by Vishay. ), all silver air core solid ribbon ( 5.5 cms. of pure silver. Almost 2kg. of silver in the bigest one. ) Alpha-Core inductors , WIMA FKP 1 and KEMET caps in the crossover, the speakers cables goes soldered directly to the crossover parts. This speaker crossover is tri-hard-wired from the amps output to the 3-way crossover parts and speaker drivers.
In reality are three separate/stand alone crossovers: one for the tweeter, one for the midrange and the other for the woofer, all these hard-wired directly to the amps ( no connectors. )
I'm only not biamp my system ( with the subs. ) but these ADS main/satellite speakers are true tri-wired in hard-wire directly from the amps to each crossover parts in the three way speaker design all the way down to the amplifier output.
I change the internal damping glass fiber by 10kg ( each one ) of long hair 100% virgin wool and change the fabric cloth of the grille for a " transparent one ".
Both speakers have at the rear-center the Antiresonant Vibration System by MICROSCAN model TM-8 that works from 20hz to 1.5Khz.
These L 2030 have: One acoustic suspension 1" silk dome tweeter, one main acoustic suspension 2" silk dome midrange, three auxiliar acoustic suspension 2" silk dome midranges ( similar to the main midrange but with a less powerful magnet. ) and two long-excursion acoustic suspension ( sealed. ) paper 14" woofers.
These are exceptional drivers especially the tweeter/main midrange ones.
These L2030 midrange design permit to " run " the speakers on " point source " mode ( tweeter and main midrange ) or through a " weighted " line source mode ( tweeter plus the 4 midranges. ), in this last " fashion " is how I have it ( hard-wired too. ). Its efficiency is 95dbs. """
The main speakers are paired with a very old true Reference M:Levinson 20.6 monobloks designed by legendary J.Curl and these amps are up graded too and between other things and due that the pure class A are coupled my capacitor I changed that input capacitor for a way lower capacitanse Wima FKP1 cap ( better that even the copper Teflon Vcaps ( I tested and the Wima outperformed the over 300 dollars Vcaps for only 10 Wima dollars and it's with this cap change that the high pass filter for the L2030 happens so no additional stage for the high pass crossover. The signal comes directly from the phonolinepreamp and the signal to my Velodyne subwoofers comes directly too from that same phonolinepreamp and I'm croosing the subs/main at around 80hz, just a beauty. My Velodyne subs are not the latest model but are the last Velodyne where the woofer drivers are builded with paper pulp material similar to the L2030 woofers and to the Evolution today subwoofers. Go figure ¡ ¡ if I'm enjoying my room system. where I'm nearer to the recording that never before ( only two self powered subs. ).
Due that the 3-way L2030 drivers are wired all in parallel the amps looks around 1.7ohms impedance and the monobloks 20.6 puts around 500 watts pure class A , nothing alter these monobloks at any SPL as nothing alter the L2030 response at any SPL. In some of my personal test proccess and with some tracks inside that test proccess I make some test with 97db SPL at seat position ( near field position ) with peaks at over a little 106db and I listened to that so high SPL only by a few minutes due that's only a performance quality test.
R.
