Sure Electronics AA-AB32313 2x400

I find my Sure 2 x 500W (AA-AB32512) amp board speaker output is intentionally clamped @ 48V.

I tried to raise the supply rail voltage to 60V (STA516BE should run safely under 65V), However, the maximum output voltage is clamped at 48V Peak (34V RMS). This gives me an unsatisfying output power (144W/each CH)under 8Ohm load.

Anyone have tried out AA-AB32514 ? I am wondering if this(clamped behavior) is the difference between AA-AB32512 & AA-AB32514.

Maybe AA-AB32514 is not clamped for higher output power (?)
 
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ICG

Disabled Account
Joined 2007
I tried to raise the supply rail voltage to 60V (STA516BE should run safely under 65V), However, the maximum output voltage is clamped at 48V Peak (34V RMS). This gives me an unsatisfying output power (144W/each CH)under 8Ohm load.

Well, 144W is probably not satisfying for you but please have a look at the numbers: The maximum power at 48V is specified at 10% THD with 500W at 3 Ohm! and 270W at 1% THD.

If you cut back the THD (noone listens to 10% THD of an amp), it gets lower ofcourse. But let's calculate it.

P = U² : R

34V² : 3 = 385,3W

380W, assuming that's at lower than 10% THD, it's perfectly normal. The datasheet says it's 270W@3ohm 48V DC THD+N 1%.

Maybe AA-AB32514 is not clamped for higher output power (?)

It actually IS - but ONLY at lower impedances. I don't know what to say, the specs are pretty clear about at which impedance the power is delivered.
 
If you cut back the THD (noone listens to 10% THD of an amp), it gets lower ofcourse. But let's calculate it.

P = U² : R

34V² : 3 = 385,3W

380W, assuming that's at lower than 10% THD, it's perfectly normal. The datasheet says it's 270W@3ohm 48V DC THD+N 1%.

It actually IS - but ONLY at lower impedances. I don't know what to say, the specs are pretty clear about at which impedance the power is delivered.

I don't get it. Where can I get a 3 Ohm impedance speaker ?

I know there're some special designed car speaker have dual 4 Ohm voice coil.

But I've never seen any single speaker with 3 Ohm or 1.5 Ohm impedance.

If 3 Ohm speaker is rarely available, what's the point of saying it "500W @ 3 Ohm"? (a wattage that you can never achieve ?) :confused:
 

ICG

Disabled Account
Joined 2007
I don't get it. Where can I get a 3 Ohm impedance speaker ?

You use i.e. 3 8 Ohm subs. Or you build it yourself. Or you use a commercialy produced '8 Ohm' speaker - which got a glorious minimum impedance of 2,8-3,5 Ohm. And yes, there are not too few of them out there. :rolleyes:

I know there're some special designed car speaker have dual 4 Ohm voice coil.

But I've never seen any single speaker with 3 Ohm or 1.5 Ohm impedance.

If 3 Ohm speaker is rarely available, what's the point of saying it "500W @ 3 Ohm"? (a wattage that you can never achieve ?) :confused:

Well, like already said above, a there are speakers which got a hefty dip in the impedance. Then there are 8 Ohm labeled speakers which are, in fact, rather 6 Ohm (Re ~5 Ohmj or lower). For extra-WAF these drivers are often used in pairs to get these elegant, slim towers.

In any case, they did not make any secret out of the circumstances how the power can be achieved. I somehow don't see how they made a mistake there and that's certainly not the 'fault' of the amplifier. I mean, the culprit would be the one who didn't read the specs properly and just went for huge wattage numbers, wouldn't it?