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I'm leaning towards the 2225 in some 4560 cabinets I will be picking up next week but at some point I will complete my set of A7 cabinets and will want to transfer the same driver to the A7. 'm thinking the results should pretty much be same, agree?
I will be driving them with 125wpc tube amps, bi-amp.
These will be in my HT and I have subs.
thanks:)
Greetings ac2 -Quote:
Originally Posted by ac2
The 2225 is not a horn loader, unless you're looking for mushy, inarticulate bass, then the 2225 loaded in a horn enclosure will perform that task, flawlessly. That speaker is at it's best loaded into a standard bass reflex enclosure.
You would be better off using a 2220 or an E130. The Thiele-Small parameters between the 2220 & 2225 will bear this out. The 2220 was loaded into all the 4500 series theater enclosures; 4520, 4530, 4550, 4560. As the 4560 and A7 are drastically different volume enclosures, you should not expect the same results. IMHO, the 4560 makes for a lousy HiFi enclosure, but the A7 has a rich history of music reproduction. However, the A7 would not be my enclosure of choice for a domestic HiFi system.
It's been my experience that many folks on forums such as this one don't have a clear understanding what the criteria is for a proper horn loading cone driver. They usually buy into popular beliefs, which in most cases is wrong. I have yet to trade comments with anyone on this forum who is intimate with the nuts and bolts of horn design, but they do put a lot of stock in canned programs with pretty graphs. The 150-4C IMO, was the best horn loader ever put in production, with the 130A/2220 as the closest second. I know JBL offered the 4520 & 4530 with the 2225, but it pales in comparison to the 2220.
The first figure of merit I consider when choosing a cone driver for horn loading, but not the only, is the Efficiency Bandwidth Product. The EBP for the 2225 is 129. The EBP for the 2220 is 194. The higher the number, the better the horn loader. Subsequently, the higher the number, the smaller the chamber volume is required for the driver. It's one of the very reasons why the 130A & 2220 work so well in the C34, 4520 & 4530 horn enclosures. The E130 with an EBP of 190 is a close second to the 2220.
The ALTEC 515 for example, was designed specifically for horn loading, but even with it stellar attributes it still requires a cavernous enclosure to operate in properly, namely, the A7 and the rest of the dual 15" ALTEC theater enclosures. I have heard only one horn enclosure with a volume much smaller than the A7 a 515-8G sounded awesome in, the Exemplar Audio Tractrix horn. The success of that design didn't happen over night. John Tucker and Jeff Marquardt spent countless hours dialing that box in.
Good luck,
H.F.
Thank you for the info! Wow :)
I just made a deal today on some A7 cabinets! So now the question is what driver should I be looking for?
2220? 515?
Thanks!!
I'm far from an Altec expert, but I believe their 15" woofer frames are larger than the JBL standard. If the speakers you're getting are actual A7s or accurate clones, you'll probably be better off with Altec woofers.Quote:
Originally Posted by ac2
Widget
Since you're starting from scratch, and you have the A7's, I would load them with the 515. There are folks out there who load the A7 with the 421, but that driver is not a decent horn loader either. If you had scored a deal, and wanted to use the 4560 I would have suggested the 2220 or E130. Mr. Widget is correct, the later model ( after 1974 ) ALTEC 15" speakers are larger, but the 16 inch frames will fit on the A7 baffle with 1/16 inch to spare between the inside top panel. The A7 and 816 baffles are the same dimension, and the newer frames were used in the 816.Quote:
Originally Posted by ac2
If you have the wherewithal, I'll suggest that you contact Bill Hanuschak at Great Plains Audio for a nice new pair of 515-8G's, rather than take your chances on an Ebay sale for speakers with no warranty, and possibly re-coned with after market kits.
H.F.
Many thanks!Quote:
Originally Posted by Horn Fanatic
I was just thinking last night if the 515-8G's were available new. I will try to go that route.
Next question I have are about the horn drivers. I ready have 3- 511B's but no drivers. Which ones and what crossover point?
Since you already have the 511's, you may as well use either the GPA 902 or 909 drivers. Bill manufactures the same aluminum diaphragms ALTEC did 40 years ago. In fact, he's stamping out the diaphragms on the same machine ALTEC used. As a former ALTEC employee I was fortunate enough to see it. Bill told me it was designed and built by Jim Lansing. It just goes to show, to manufacture quality products you need quality machinery. That machine is at least 70 years old, and it keeps on chuggin' away. Even the riveting machines I used were WWII vintage.Quote:
Originally Posted by ac2
H.F.