Replacing Cabinet Speakers

[MadJayJaspers]

This question was brought up mostly out of curiosity, partially for future reference. I've done lots of research and can't seem to find anything about this. If I wanted to replace the speakers in a 4X10 cab with 4 Eminence Legend B810, each one rated at 150 watts, would that mean the cabinet as a whole could handle 150 watts, or 600 watts, or is there some other way of calculating that?

 

[B-string]

600 watts IF the cab can be made to tune for the speakers .

 

[MadJayJaspers]

600 watts IF the cab can be made to tune for the speakers .

aaaannnnddd now you lost me XP what does that mean?

 

[mbelue]

The relationship between a cabinets size and the length size and quantity of ports is a cabinets tuning.
It will determine how much of the electricity coming from your amp makes low frequency sound and how much is wasted breaking your speakers.

 

[B-string]

Speaker boxes are built for a speaker needs not the other way. If the speakers needs are met it can couple properly to the environment around it and the power handling is good. If not it might flap uncontrolled like when not in a box and only handle 25% of its rating.

 

[AstroSonic]

This question was brought up mostly out of curiosity, partially for future reference. I've done lots of research and can't seem to find anything about this. If I wanted to replace the speakers in a 4X10 cab with 4 Eminence Legend B810, each one rated at 150 watts, would that mean the cabinet as a whole could handle 150 watts, or 600 watts, or is there some other way of calculating that?

There is an optimum cabinet volume and tuning frequency for a given driver (or drivers) and a target bass response profile (how deep the bas extends and how peaked or flat the response curve is). Both the cabinet volume and tuning frequency are critically matched to the driver characteristics. So, to answer your hypothetical question: an increase in power handling (in your example to 600w), from the upper bass upward, could be had by replacing the stock drivers with drivers having greater power handling. Unless the new drivers had the same electro-mechanical (TS) parameters as the stock drivers, the power handling in the mid and low bass might be the same, better or even less than the stock drivers - its a crap shoot. In reality there is a moderately wide range of useful cab volumes and tunings for a given driver and bass response goal. Also keep in mind that, if the goal is more volume, the driver sensitivity is as important as the power handling. For example, driver A handles 200w and has a sensitivity of 98 db/w/m. Driver B can handle 400w and has a sensitivity of 95 db/w/m. Driver C handles 200w and has a sensitivity of 99 db/w/m. Which driver will be the loudest? Drivers A and B will produce the same spl, while Driver C will play slightly louder. Of equal importance is the fact that Driver A can equal the volume of driver B with half as much power. And we haven't begun to talk about excursion limited power handling! So, replacing stock drivers with drivers having greater power handling will not necessarily result in an increase in volume. Chances are that such an 'upgrade' will result in some sacrifice of performance, and quite possibly in blown drivers.

 

[B-string]

aaaannnnddd now you lost me XP what does that mean?

You think you're lost now?

There is an optimum cabinet volume and tuning frequency for a given driver (or drivers) and a target bass response profile (how deep the bas extends and how peaked or flat the response curve is). Both the cabinet volume and tuning frequency are critically matched to the driver characteristics. So, to answer your hypothetical question: an increase in power handling (in your example to 600w), from the upper bass upward, could be had by replacing the stock drivers with drivers having greater power handling. Unless the new drivers had the same electro-mechanical (TS) parameters as the stock drivers, the power handling in the mid and low bass might be the same, better or even less than the stock drivers - its a crap shoot. In reality there is a moderately wide range of useful cab volumes and tunings for a given driver and bass response goal. Also keep in mind that, if the goal is more volume, the driver sensitivity is as important as the power handling. For example, driver A handles 200w and has a sensitivity of 98 db/w/m. Driver B can handle 400w and has a sensitivity of 95 db/w/m. Driver C handles 200w and has a sensitivity of 99 db/w/m. Which driver will be the loudest? Drivers A and B will produce the same spl, while Driver C will play slightly louder. Of equal importance is the fact that Driver A can equal the volume of driver B with half as much power. And we haven't begun to talk about excursion limited power handling! So, replacing stock drivers with drivers having greater power handling will not necessarily result in an increase in volume. Chances are that such an 'upgrade' will result in some sacrifice of performance, and quite possibly in blown drivers.

Excellent answer.

 

[pie_man_25]

If you didn't understand any of that, in a nutshell, the box that the speaker is put into does more than just hold the speaker. Have you ever wondered why a 410 for bass, in spite having smaller speakers, has more internal volume than a guitarist's 412? In a nutshell, in order for the speaker to make those rumbly bass noises that we love, the space inside the speaker needs to be tuned to the driver. Think of it as elbow space for sibs waves. Changing the speakers in a cabinet, even of the same size, can be a crapshoot unless you know what you're doing. Internal volume and port tuning dues more than just affect frequency response, it can also affect power handling. In this regard, it's good to do a bit of reading.