Technical Help Please Herseys I vs II's

[dklowery]

Can someone tell me the difference between the Hersey I and II?

Do they sound the same?

Is there a difference in the sonic features in perfromance?

How can you tell if a Hersey speaker is a I or II model?

[Groomlakearea51]

Can someone tell me the difference between the Hersey I and II?

Construction materials: H-I is 3/4 birch plywood or "lumbercore"; H-II is MDF; H-1 has removable back panel; H-II is "permanent". Note: H-II motor boards were 3/4" birch plywood.

Drivers: The H-I used a K-22 woofer, K55 midrange on a K700 metal horn, the K-77 tweeter and the Type E crossover (note early Heresy's used a type "C"); Starting in late 1983 or so, the final H-I's were produced with the K-24 woofer, the K-53 midrange on a K701 plastic horn but still retained the the K-77 tweeter. These modifications also required a type E2 crossover. The H-II's used the K-24 woofer, the K-53 midrange on a K701 plastic horn and the K76 tweeter. The H-II drivers were, however, mounted from the front.

Appearance? Virtually identical unless you remove the grills; H-II drivers mounted "flush"; also rear panel has terminal "cup". Early (late 85 and 86 were round); late 86 started using the square cup which is the same dimension and appearance as the H-III's.

Look at this thread and you can see the "internal" differences, and how to refinish the different types: http://forums.klipsch.com/forums/t/109693.aspx

For finishes, serial numbers, driver differences, etc. see: http://forums.klipsch.com/forums/p/103886/1048788.aspx#1048788

Do they sound the same? Is there a difference in the sonic features in perfromance?

Sorta'..... It's a preference "thing". Specs are almost the same. H-II is probably slightly better in the bass, but because the cabinet on the H-I is "leaky" after 30 years. I like the H-I because the midrange K55 is better (my opinion) than the K53.

Hope that is of some assistance.

[dklowery]

Thanks again for the repsonses.

[TBrennan]

51----What's the difference between a K-22 and a K-24? The K-55 and K-53?

[Groomlakearea51]

Bob has the "Q" and other parameters on the differences. I've got them somewhere.... but my "paperwork" is a mess today. Functionally, from what I was able to understand from various folks that I spoke to during the "project", the K-24 supposedly provided a smoother bass up through the 700 Hz crossover point. Arguably, of course, the K-22 was supposedly better in the below 100Hz area. Unfortunately, there are no NIB "NOS" 22's around. The 53's were also supposedly less harsh in the upper mids than the K55's on the 700 Hz horn. I believe that Dr. Who may also have some data on the two differences. From the practical point of view, the production cost of the K55 (Atlas PD5's) was too much and they went to the 53/701 combination. Much less expensive and the actual 52 or 57 ceramic worked probably as well, at least on the Heresy and Cornwall. It is interesting that the 55 (in it's various configurations) remained on the LS's and K-horns, and Belles through the end of their production.

[TBrennan]

Thanks. So I take it the K-53 is the Hepnerish ferrite driver, probably with a smaller diaphragm than the Atlas. I had some oddball Hereseys with those.

[Groomlakearea51]

Absolutely. They first appeared in 84 in the H-I's. The 24's appeared in late 83 or so. By the time the H-I run was over in late 85 (I actually have a pair of 85 H-I's), only the K-77 was left. Thus the E2 crossover.