AL III Plus issue with Emotiva Amp.

I have acquired a pair of AL III Plus speakers. After a minor repair on one of the tweeters, everything seems to be working fine.

The issue I have is that if I try to drive the speakers at a high volume, my amplifier (Emotiva XPA-2) will go into self protect mode when a particularly dynamic bit is playing. I have been running this amp with a pair of KEF 105/4s which are 86 db efficient with no problem.

If we assume that the amp is ok, then the problem is in the speaker, or this type of speaker doesn't play well with this amp. I posted on the Emotiva forum, and someone there said they had no problems with a similar setup.

My question for this group is;

Is there a component in the speaker (most likely the crossover) that can short when it receives to much power?

Alternatively, anybody have any other ideas on what might be going on?

Paul

clipping? Those speaks suck up alot of power.

This is not the fault of the speakers. The amp does not have the balls to handle the AL III's I would suggest replacing the amp or cutting back on the volume befroe you damage the amp, or the speakers. I must admit that I have never been a fan of Emo gear, and this is just another example as to why. They look great, but when faced with anything more challenging than an 8 ohm load, they fall flat on their face.

Sell the Emo and get a Sunfire 300/2.

This is not the fault of the speakers. The amp does not have the balls to handle the AL III's I would suggest replacing the amp or cutting back on the volume befroe you damage the amp, or the speakers. I must admit that I have never been a fan of Emo gear, and this is just another example as to why. They look great, but when faced with anything more challenging than an 8 ohm load, they fall flat on their face.

Sell the Emo and get a Sunfire 300/2.

Before you do that, try bi-passing the passives and go active. Those passives are really inefficient. When I had mine I couldn't drive them to the levels I wanted sometimes with 4 M-500t's until I bi-passed and went active.

Those are 4 ohm speakers and according to what I was told, those ribbons will actually dip below 2 ohms at times. Hell on any amp.

XPA‐2
Number of Channels: 2
Topology: Fully Discrete, Dual Differential, High Current, Short Signal Path Class A/B
XPA-2

Power output (all channels driven):
500 watts RMS @ 4 ohm (0.1% THD)
300 watts RMS @ 8 ohm (0.1% THD)
Power Band Response: 20 Hz to 20 kHz with less than .05db deviation at rated power
Broadband Frequency Response: (‐3db): 5Hz to 150kHz
Amplifier Gain: 32db
Signal to Noise Ratio 1 watt: >91db Full Power: >110db
Input Impedance:
Unbalanced ‐ 23.5kohms
Balanced ‐ 33kohms
Transformer Size: 1,200VA
Secondary capacitance: 45,000uF
Output Devices: 12 per channel
Size: 17” W x 7.75” H x 19” D
Weight: 75 lbs (89 lbs boxed)
continued

I didn't see anything in the owners manual that states this this amp is stable below a 4 ohm load. If that's the case, you need a different amp or new speakers.

Remove the jumpers between the rear binding posts & check both the woofers & ribbons impedance with a multimeter. Woofers should be a straight 4 ohms & ribbons should be about 3.6-3.8 ohms.

If you get any other readings, you have an issue with a driver OR, more likely, the crossover. The AL-III fuses are supposed to be MDQ-4 slo-blo. Anything else won't protect properly.

let us know what you find.

Sorry I didn't get back to checking this thread until now. I spent most of the day hanging out with James at his shop. He fabricated a new set of bases and tops for the AL III Pluses. Then I had to come home and get them installed. They look great. When I bought the speakers the tops were missing, and the bases look like they had an argument with a vacuum cleaner, and it won.

Regarding the speakers, I will test the speakers sans jumpers, and double check the fuses to make sure no one has been mucking about with them.

As far as the Emotiva Amps, I would probably sell the speakers before the amps, as I do like the sound of my KEF 105/4s. In fact at this point I am not sure which pair of speakers I will keep for the fronts even if I can get the setup working well with the AL IIIs.

Right now I am working on the cosmetics, as SAF is an issue, and the AL IIIs are not as aesthetically pleaseing as the KEF's which my wife accepts aesthetically, as well as sonically.

Thanks for all the help.

Paul

OK, I have run the tests as described and have what I consider odd results. The good news (hopefully) is that both speakers exhibit the same wierdness.

First, I checked all fuses, and they are 4A 250V fuses, and test good.

I disconnected the jumpers and tested the woofers, and they are reading 4.9Ohms. When I tested the ribbons, the meter registered for a second, and then read open. Everytime after that the meter read open with no flicker. It did the same thing on both speakers. So, I decided to play some low volume sound through the drivers, I hooked up the woofers only, adjusted the volume to pretty low, and then moved the wires up to the ribbons, and low & behold they worked. I said to myself "HUH?" so I tried the meter again and it did the same thing it did the first time, only this time I was prepared, and the meter settles on about 5.32 Ohms before displaying open. So I put the wires back onto the ribbon connectors from the amp, the ribbon worked, I took them off and tried the meter and got the same results.

So, anybody got a clue as to what is going on? My thought (and I know squat about electronics) is that a capacitor in the Xover doesn't like the DC used when measuring ohms, and says, "I ain't gonna play this game..." and goes open. Why sending a music signal through it, fixes the problem, I haven't a clue.

Does this explain anything?

Paul

You have a problem Paul, your ohm readings should be close to what Gary told you. Mine were when I checked them.
I would suggest pulling the fuses and running another impedance check on the ribbons. I may be full of beans, but I don't think it'll feed through the crossover if you remove the fuses ? Am I full of it guys ? It's been a while since I sold mine to stereo_dog.
Either that Paul, cut the wires going up to the ribbons and then run a direct impedance check. They should read real close to what Gary mentioned. He knows the AL-III's like the back of his hand.

You have a problem Paul, your ohm readings should be close to what Gary told you. Mine were when I checked them.
I would suggest pulling the fuses and running another impedance check on the ribbons. I may be full of beans, but I don't think it'll feed through the crossover if you remove the fuses ? Am I full of it guys ? It's been a while since I sold mine to stereo_dog.
Either that Paul, cut the wires going up to the ribbons and then run a direct impedance check. They should read real close to what Gary mentioned. He knows the AL-III's like the back of his hand.

If you are measuring from the binding posts, the fuses must be in to both measure and play.

I was measuring from the binding posts, and yes, the fuses were in when I measured.

Paul

Thanks for clearing that up BillD. I didn't think I was thinking right ! It's been awhile.
What if Paul were to pull the cross overs out and probe off the leads going to the ribbons, would this give him an accurate reading ?

Yes.

okay on mine,.....
not the plus,....
which means mine have pots, all set straight up, stock woofers and ribbons.....
checking with both jumpers in I get 6.4ohm
just the woofer, I have 6.4 (pot straight up) but if I turn the pot it changes the ohms reading
just the ribbon it goes to 4.0ohm then meter goes open, so my guess is the caps in the xover do this
if you want to check the ribbon,....
look at the backside, right at the point the ribbon frame meets the woofer cabinet there you can see the ribbon wire connection point, put your meter here.
I get 1.8/1.9ohm

so if I read this right, it plays if the woofers are unhooked? does not clip the amp.
well if thats the case I bet the woofers are shot....
I have 2 sets of the, and all 4 woofers had issues, 2 fully blown,(rubbing VC, and melted)
the other set the spiders had busted loose, letting the VC rub the pole, making noise, and a short.....