Here'ws all I know about the 2035 so far...
I too am curious to know more about these woofers. I own three pair of them along with three of the 4508A cabinets they came in as 4638 LF cinema systems. From what I've read, asked, and compared to my others JBL drivers, the following facts and assumptions came about:
I just befriended a recently-retired JBL employee through some ebay auctions, and he said that the 2035H was something JBL developed as a cheap alternative to 2226's during the theatre-building craze of the '90's to compete with the likes of Peavey and others for a lower-priced JBL. I asked him about the 2035"HPL" and aquaplas. He confirmed my suspicion that Aquaplas is used for several things, depending on the application: a stiffener on large cones, notably near the outside edge, a dampener on diaphragms, and a mass increaser. He has offered to try to get me more information about the 2035H(PL) from friends he has in various departments (including Engineering) at JBL. So far, I haven't heard anything yet...
There are apparently two versions of this woofer, a 2035H and a 2035HPL.
I have come to assume that the original 2035H had a copper coil, and the 2035HPL has an aluminum coil and uses aquaplas (hence the HPL designation), My guess is aquaplas is used mainly to add mass to make up for the lighter aluminum coil. Both are rated at 400 Watt AES anywhere they are mentioned on jblpro or jblproservice websites.
However, the JBL Thiele-Small parameters list shows a 2035H, NO 2035HPL, but rather a 2035HPL-1, with slightly different data for the two versions. I have deduced that some of the data is simply expressed in different standards of measurement (like metric vs. english standards), but there are other diffs as well, like efficiency, Qms, PE, and Fs. Go figure... :blink:
The 2035HPL Tech mnl .pdf lists the woofer as rated at 400W AES, and having an aluminum voice coil. There is no tech mnl .pdf on the 2035H or the 2035HPL-1 on their websites. The previously mentioned Theile-Small parameters set the 2035HPL-1 at a 300 Watt rating.:biting:
The "Architectural Specifications" section of the 4638 brochure .pdf states an 800W AES power rating for the cabinet describes the 2035H(no PL) as having a copper voice coil,:wtf:
The 4638 Tech mnl .pdf shows the cabinet having two 2035HPL woofers with a power rating of 800 W AES for the cabinet. The cabinet has no crossover, just input terminals.
the 4638TH tech mnl .pdf lists 2035H and describes it as having an aluminum coil. The "TH" model includes a passive crossover, and the system is rated at 800W AES pink noise for the pair of woofers. AFAIK, pink noise is part of the AES test standard, so this is just a redundant remark, IMHO. :bs:
There is no data on a 2035H on the site anywhere except in the alpha-numeric listing, which says nothing more than 15" woofer, 500W.
The 2035H and 2035HPL are rated at 400W AES everywhere else it is mentioned on the website, save for the 2035HPL-1 in the Thiele-Small parameters list...
I own several versions of the SHG- magnet JBL drivers: 2022H, 2032H, 2035HPL, and 2012H 10" mid. After removing the 2012H magnet cover (a "window dressing" that actually fell off during shipment to me) I made some comparisons to the four drivers' magnets:
All 4 magnets measured exactly the same from the outside. The back plates, the magnet slugs, and the front plates were the same diameter and thickness on all four drivers.
Everything I've turned up about these four drivers suggests that they all use the same aluminum flux stabilizing ring at the rear of the pole piece where it meets the back plate.
Everything I've turned up about the 2012H midrange and the 2035H(PL) suggests that these both use similar, if not identical, copper sleeve flux stabilizers in the voice coil gap region. I don't know about the 2022H or 2032H having copper rings around the pole piece in the magnet gap; I have a couple of 2022H's to recone soon, and will investigate this when I cut the old cones out.
It seems logical that, in order to maintain production costs/efficiency and simplify inventory management, JBL would less rather than more versions of a magnet than necessary. Sincew the 2035H(PL) was designed to work through the critical midrange up to where a horn could take over, I'd bet the magnet is the same one used in the 2012H. After all, movies are mostly dialogue, and JBL was trying to keep the system cost as competitive as possible a la two-way systems; even passive crossover versions were produced and a single 2035HPL with a 2416H/2373 90x40 horn mini-system was sold for small theatres!
The 2035 HPL has a spider with a much larger outside diameter than the other 20xx drivers use to accomodate the much longer excusion than the 2012H,2022H, or 2032H. The maximum linear travel (Xmax) spec of the 2035HPL is identical (.4 inch) to the 600W 15"VGC 2226!
Although the 2035H(PL) doesn't handle quite as much power as a 2226, it is rated as 1 dB more efficient than the 2226, making its' overall output on a par with less power required. The 2226's power compression spec at full power (600 watts) is 4.6 or 4.0 dB, depending on which 2226H brochure you read(older or newer one). By extrapolating the 4638 systems' power compression spec at full power, the 2035HPL is 3.2dB at 400 watts. At half-power, the specs read 2.5 dB at 300W for the 2226, and 1.9dB at 200W for the 2035HPL.
When you compare JBL's published half-space reference efficiency between the the 4638 at 8% to the identical cabinet loaded with 2226's (the 4648) at 7% it seems to confirm this. Also, taking the 4638's maximum acoustical power output (before power compression factored in at 64 acoustical watts, then factor in 3.2 dB of power compression listed next, it adds up almost exactly to the 4648's rated maximum power output of 28 acoustic watts.
Oddly enough, the 4638/2035 cabinet and 4648/2226 cabinet are both rated at 100dB/W/M, even though the 2035HPl is rated at 98dB and the 2226 is rated at 97dB. More contradictory information from our friends at JBL... if the driver SPl specs are accurate, and the power compression specs are accurate, the 2226 will produce no more SPl at its rated power of 600W than the 2035HPL can at its rated power of 400 watts- 50% more power in watts represents a 1.87dB increase.
Comparing the frequency response plots, the 2035HPL/4638 system frequency response is much flatter, without the big hump above 325 Hz that the 2226/4648 exhibits. The notch at 800Hz exists in both systems (although it measures deeper in the 4648) seeming to confirm that it results from comb-fiter effect phase cancellation from two spaced drivers on the same baffle, meaning a single 2035HPl shouldn't exhibit these problems.
The stated harmonic distortion spec on the 4638 (2035HPL) is under 0.8% 2nd, and 1% 3rd from 100-500Hz at 100W, while the 4648 (2226) is stated at less than 2.5% from 40-800Hz at 100W. The distortion plots are debatable as to signicant differences; you be the judge. Could be insignificant; different day, different system -no matter how close a person tries to duplicate the setup, some differences can and will crop up. Ears would have to be the judge here.
All this being said, I see the 2035HPL as no slouch; in fact it may be more efficient and produce the same SPl at 400W as the 2226H with 600W. The 2035HPl also appears to have flatter frequency response, and lower distortion up to 500 Hz than the 2226H. And the bonus is it costs a hell of a lot less than the 2226, and a much smaller amplifier should do the same job. Time will tell if this holds true. The copper should yield sweeter upper mids if you require it, and easier passive crossover design. I just wish I had a pair of 2226H's to put head-to-head with these...