ESS Heil AMT dump

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Flaxxer,

Looking at the FR for the woofer, I think you are right, you could do higher. But it's really important for you to know the performance of your tweets before you buy a woofer. :)

It is important you look at the FR chart, not just the web page min/max IMHO. That will give you a better idea of the challenges in making them work together.

Best,

E
 
Flaxxer,

Looking at the FR for the woofer, I think you are right, you could do higher. But it's really important for you to know the performance of your tweets before you buy a woofer. :)

Best,

E

Well, I know these particular tweets were used in the Tempest Series. ESS had the LS4, LS5, and LS8 which all used this tweeter. All of them used the same 2400 xover point. The speakers all ranged from 94-96 sensitivity. The Faital is 96db efficiency.

Actually, it was the only woofer I could find which was high efficiency, and could dig down to 40hz, while playing relatively smoothly, high enough to cross at 2400. Took me two hours to find it.
 
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Um, you should also know the relative efficiency of your tweets. You want your woofer to end up after the crossover is done at or below the level of your tweeter, not above it. If it's above, you have to pad the woofer, which would cause the most heat / power loss. Better to go the other way.

Best,

E
 
Um, you should also know the relative efficiency of your tweets. You want your woofer to end up after the crossover is done at or below the level of your tweeter, not above it. If it's above, you have to pad the woofer, which would cause the most heat / power loss. Better to go the other way.

Best,

E

Duh .... what was I smokin ? That's something I have already learned ... and apparently quickly forgot! LOL

But now, I have a question ... If ESS states the LS4 at 96db efficiency, wouldn't that be based on the woofer's sensitivity, since the tweeter would have been L padded down to meet it ?
 
Flaxxer,

More or less. :) The low pass filter and any baffle step compensation circuit will usually take away some DB's from it though. You trade off efficiency for bass response. So a driver that specs at 94 may end up around 91 after the LP filter is in. Then you have to pad the tweeter down to 91.

Take a look at the SNR-1 finished design. You will see what I'm talking about. This chart shows you the measured, raw woofer, the final woofer, and the total system response. I think this is fairly typical:

attachment.php


Ignore the thin blue line, that's phase I accidentally left in. The point is, notice the topmost is the efficiency as measured, or from the spec sheet. Notice how the addition of the LP filters reduces this a great deal. We go from around 92 dB @ 1kHz to 87dB after the LP filter is applied. This is so the final response from 60Hz-100Hz upwards is flat or descending. Without this most woofers would exhibit a rising response, with great efficiency, and no bass. :)

Best,

E
 

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So I also can't really try and find a woofer to use with my AMT, until I first measure the AMT ? That doesn't make sense. Then no-one could choose a driver to use, without first having it to measure.

@eriksquires ... So what you are telling me, is since the ESS LS4 is a 96db efficient after xover, I should be looking for closer to a 93db efficient woofer?
 
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@picowallspeaker ... I could honestly care less bout the size of the woofer. I was wanting nice bass to around 40 - 45 hz. The driver I found is the only one that seems to do that, and play midrange well.

an 8" driver would be just fine, if I could find one that did that, AND was also at least 93db efficient
 
Hey Flaxxer, maybe this anemic woofer needs a bit of a stretch after all these years of doing who knows what. Can you visualize yourself measuring TS parameters anyhow?

I'm sorry Lozjek. I just do not have enough nostalgia for the ESS speakers to keep it all original. I may keep it in the original cabinets. But not the original woofer.

I would trade them to you, if you were local ;) But the shipping would be a real biotch !!!! :eek::eek::eek:
 

That would be very counter intuitive. I have a pair of Heil ESS AMTs which can play VERY loudly, and sound good doing so. I need a bass driver that can hang. At least an 8" as a minimum, and it would have to be a real bad *** !
 
So I also can't really try and find a woofer to use with my AMT, until I first measure the AMT ? That doesn't make sense. Then no-one could choose a driver to use, without first having it to measure.

@eriksquires ... So what you are telling me, is since the ESS LS4 is a 96db efficient after xover, I should be looking for closer to a 93db efficient woofer?


1. In your case, only because you don't have the manufacturer's specs, but still, after mounting, you should measure each driver separately to get an accurate crossover design.

2. Nope, the other way. you start with a driver that the _driver_manufacturer_ (FaitalPro, Peerless, etc.) specs at 96-98 dB at 1kHz / 1w /1m and expect that your crossover will cost you 3-5 dB, and you will end up at 93 dB (ESS).

The worst case scenario is your woofer, post crossover is more efficient than your tweeter. Padding the woofer is much more power wasting.

Best,

Erik
 
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