Is box rise of this magnitude normal?

[Sephious 10+ year member]

So I've been told to measure box rise you clamp the positive wire (or negative?) of the sub and then read the voltage out of the amp, then divide the voltage by the amperage and you have your actual resistance, or the actual power the sub is getting by multiplying both.

I've wired my 2 SA-8's D4's down to 1 ohm and my calculations show that the resistance reading is almost 2.5. Is it normal for box rise to be so high?

Thanks.

Click to read more...

 

[ahole-ic]

So I've been told to measure box rise you clamp the positive wire (or negative?) of the sub and then read the voltage out of the amp, then divide the voltage by the amperage and you have your actual resistance, or the actual power the sub is getting by multiplying both.
I've wired my 2 SA-8's D4's down to 1 ohm and my calculations show that the resistance reading is almost 2.5. Is it normal for box rise to be so high?

Thanks.

Yeah. That's really not THAT high for a musical system.

 

[Sephious 10+ year member]

Alright, well I guess I can feed the subs significantly more power than before

With the box rise they're only getting about 250 watts. That's not even enough for one of them, rather than two. No wonder I thought they were so quiet!

 

[ahole-ic]

Alright, well I guess I can feed the subs significantly more power than before
With the box rise they're only getting about 250 watts. That's not even enough for one of them, rather than two. No wonder I thought they were so quiet!

Rise is dependant on frequency. At other frequencies you are getting MUCH more than 250 watts. You measured your rise at 1 frequency. Don't turn your amp up to compensate. You WILL blow something. Next, there is no such thing as "not enough for one of them". RMS is not a requirement. It's a maximum limit for everyday usage.

 

[Sephious 10+ year member]

Rise is dependant on frequency. At other frequencies you are getting MUCH more than 250 watts. You measured your rise at 1 frequency. Don't turn your amp up to compensate. You WILL blow something. Next, there is no such thing as "not enough for one of them". RMS is not a requirement. It's a maximum limit for everyday usage.

I'm aware of the second fact. I'm talking about for my listening purposes.

 

[Big Dog Louis 10+ year member]

Also you must take into account that in order to get more out of your amp you will have to lower your nominal impedance....which in return is very dangerous for everyday use. Using an amp at less than its stated impedance load will cause it to clip and eventually blow so just be careful with that. And by the way a 2.5 rise is not bad at all.

 

[Sephious 10+ year member]

Rise is dependant on frequency. At other frequencies you are getting MUCH more than 250 watts. You measured your rise at 1 frequency. Don't turn your amp up to compensate. You WILL blow something. Next, there is no such thing as "not enough for one of them". RMS is not a requirement. It's a maximum limit for everyday usage.

You were absolutely correct. My box rise was only .25 at the lowest, which makes for 1.25 or so total, after testing through all the bass frequencies.

Also you must take into account that in order to get more out of your amp you will have to lower your nominal impedance....which in return is very dangerous for everyday use. Using an amp at less than its stated impedance load will cause it to clip and eventually blow so just be careful with that. And by the way a 2.5 rise is not bad at all.

My amp is stable down to 1 ohm by manufacturer specs, so I don't have any problems in that regard since disregarding box-rise I'm at a 1 ohm load.