For AUTOMOJO: ESS Replacement Woofers

[tromboneman]

I understand you are the ESS Heil Guru so I am asking your advice on the 10" drivers in my AMT3 "Rock Monitors".

I bought this pair of speakers from the original owner, who used to be the dealer, back in 1974. They are still in like new condition. The original owner had the four 10" drivers replaced in the early eighties with Pyle drivers, when the old surrounds rotted out. He said they were an improvement over the originals. I am a long time ESS fan, having owned several sets, but this is my first set of AMT3's so I don't know what to expect from them. They do sound better than the AMT1aM units I had before these.

The bottom end seems full and tight with the Pyles in there, and I am trying to decide whether to just leave them, or try something else, or perhaps look for a set of the original ESS drivers and fix the surrounds. I have been told the Peerless used to be a good match, but that the new ones are not the same. Same with Eminence. I am a jazz musician and a critical listener, but I don't have piles of cash to spend for a "slight" improvement.

I will welcome you thoughts/advice with great enthusiasm!

Thanks.

 

[Sir.Byrd]

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=264-620

 

[wiredbecker]

Very cool. Thanks for the heads up Byrd.

 

[Sir.Byrd]

They also have the 12" version and I believe 10 and 12" passive radiators (with spiders)
also new great-heils, as well as diaphragms.

 

[automojo]

The only problem with those new ESS woofer is they will reuquire a bit of work because the AMT3's was round woofer holes vs the semi truncated ones of the new ESS woofers.
They should work well, as their specs are similiar to the O.E. woofers
The Eminence 1040SF from OCS is a excellent choice as well, and works well with the stock cabinet, and are a bit cheaper then the ESS woofers. Eminece still makes some pretty good speakers. The 1040sf's are a 'OE' configuration specified by OCS to be a good replacement for ESS spoeakers, among other things. They do have a foam surround, but new materials make them last alot longer. One advantage of having foam surrounds is that they enable the woofer to perfoarm it's piton action in a more linear fashion than many rubber surrounds as they are actually 'stiffer' in the horizontial plane. Rubber surround do provide some damping effect as their resistence to veritical movement take a little more force. Regarless they work well, and can benefit even more with a Sonic Barrier treatment to the cabinet.
From my calculations each AMT3 cabinet has 3.2-3.3 lbs of stuffing in a 2.9 cft cabinet-so they are 'ovedrstuffed' from the factory-which was intentional. The norm is around 1/2lb per cubic foot.
How they would sound vs the Pyles you have is really any ones guess. I have never hear a set with Pyles, and the model number may be differnt then someones elses who also has Pyles.
The Pyles are pretty efficient, and probably accounts for the good sound.
Woofer replacement can be a crap shoot, and it sounds like the previous owner did the foot work/ear work for you.
The problem some have with the O.E. woofers is probably more of a quantity vs quality issue. In part this has to do with the Alnico driver losing charge and the woofers dropping a db or 2 vs the Heils and transition driver. Those Pyles probably made the balance more to the originals owners liking by re-upping the efficincy and output.
In part this is why IMHO many have problems with home brew speakers in matching a woofer up to the Heil-they try to take a Sea's etc-a high quality woofer-that's low in efficincy and probably over damped-not a good mix.
But my advice would be if you like the way they sound-I would leave them, and perhaps spend some money updating the crossover, sealing the cabs etc, if you wanted to do something. Or add some Sonic Barrier etc.
But if you really like the way they sound, I would probably just leave them as is, and save your money and enjoy the music!!