Modification of a combo??

[stolenband]

Hello to everyone out there, and i am sorry for so many posts.

I have a Question.

Would it be to any advantage to re-design my combo amp?? What i plan to do is make it a closed amp, plus upgrade the driver. It currently has an 8 inch driver with an unknown impedance (guessing 8?) So would it be to my advantage to make the box bigger, and make it closed?? i want to increase volume, so will doing this help?? I can not hear it well at a comfortable volume at 50 feet away, and i will be at an outdoor gigs.

Any other ideas how i can mod this

it is a crate G10XL.

[chris661]

Unlikely. An 8" driver just won't do it, especially with the limited power input available.

[Cassiel]

Best idea is to build a separate cabinet fitted with a 12" and bypass your speaker. Read this:

Peak SPL Calculator

[Minion]

a closed back isn"t going to make it louder and a bigger speaker won"t make it louder because it takes more power to drive a bigger speaker (of the same sensitivity and impedance) ......

if you want it louder try a more sensitive speaker , a 93db speaker would be twice as loud as a 90db speaker , and a 96db would be twice as loud as a 93db ......

I use a 101db speaker in one of my amps and it is loud enough to jam with a drummer when only on about 3 (100w amp) .......


Now a bigger speaker that was much more sensitive than your 8in would probably get you a louder and bigger sound ........

[unclejed613]

yeah... what he said..... it's usually less expensive to find a better speaker than to get a bigger amp. the price difference between a 90db and a 93db speaker is fairly small, but the difference in price between a 100W amp and a 200W amp is usually rather large, but the result of a 3db increase in SPL is the same.... likewise you might pay maybe twice as much switching from an 85db speaker to a 95db speaker, but the price difference between a 100W amp and (if you can find one...) a 1000W amp is prohibitive, but either way you get a 10db increase in SPL (assuming of course the 1kW amp doesn't vaporize the voice coils on the 85db speakers first...)

[chris661]

Originally Posted by Minion

a closed back isn"t going to make it louder and a bigger speaker won"t make it louder because it takes more power to drive a bigger speaker (of the same sensitivity and impedance) ......

if you want it louder try a more sensitive speaker , a 93db speaker would be twice as loud as a 90db speaker , and a 96db would be twice as loud as a 93db ......

I use a 101db speaker in one of my amps and it is loud enough to jam with a drummer when only on about 3 (100w amp) .......


Now a bigger speaker that was much more sensitive than your 8in would probably get you a louder and bigger sound ........

A +3dB change requires double the power (to match), but a +10dB difference is perceived as twice as loud.
What makes you say you need more power to drive a bigger speaker?

Chris

[Keriwena]

Originally Posted by chris661

....a +10dB difference is perceived as twice as loud.

By monkeys listening to sine waves on headphones, perhaps, but for over two hundred years four violins have sounded "twice as loud" as one violin to concert goers listening to real music in a hall.

[chris661]

Four violins:

each doubling of radiating area gives +3dB, and each double of input power gives +3dB.

The example you've given would have +12dB over a single violin. Which, it has to be said, isn't far off +10dB.

[Keriwena]

Originally Posted by chris661

Four violins:

each doubling of radiating area gives +3dB, and each double of input power gives +3dB.

Are you asking each musician to play twice as hard, or are you specifying two violinists per instrument?

[chris661]

Each violinist puts in the same amount of effort as the first violinist on his/her own.
So there's 4x the acoustic energy from the sum of people operating the instruments, and another 4x from the extra radiating area of the violin bodies, strings, etc.
A 16x increase in acoustic energy gives +12dB.