Mystery Speakers

[curtisthorpe]

Hi

I recently bought a little battery powered 30w P.A. system to take give me some more volume for my street performances. I'd like to swap out the stock mystery speakers for something that can give me a bit more volume. The cab contains 2 15w woofers (6.5") and two 15w tweeters. I've emailed the manufacturer inquiring about the SPL of the woofers but they did not give me an answer.

I know little about speaker swapping and I have a few amateur questions:

Is there anyway to tell the SPL or overall quality of a speaker without knowing its specs?

Is it worth swapping the tweeters as well? I was thinking just replacing the woofers would probably give me the best bang for my buck.

The original drivers/tweeters are 4ohm and i was thinking of replacing the woofers with some along the lines of this eminence:
http://www.parts-express.com/pe/show...number=290-399.
but I'm a little confused about speaker wattage.
Will it be a problem if I replace a 15w speaker with a 100w speaker?

Any recommendations for a 6-7" speaker that is 4omhs and very efficient?

Any info/suggestions are very much appreciated.

[Whitneyville1]

You don't want a higher wattage speaker as they usually give less dB (sound output) per watt. What you would want is a more efficent speaker that gives more dB per watt. Your problem is you have no idea of the efficentcy of the speakers you have, and measuring them would take about $300 of equipment (calibrated microphone, connector to computer, etc.). Maybe someone here may be near you with an Omnimic to measure them, or someone may have a better idea.

[Chris Roemer]

You don't want a higher wattage speaker as they usually give less dB (sound output) per watt. What you would want is a more efficent speaker that gives more dB per watt. Your problem is you have no idea of the efficentcy of the speakers you have, and measuring them would take about $300 of equipment (calibrated microphone, connector to computer, etc.). Maybe someone here may be near you with an Omnimic to measure them, or someone may have a better idea.

The Woofer Tester takes a pretty good stab at SPL.

[ocool_15]

You can measure T/S specifications with a decent multimeter, amp, computer and resistor. If you sacrifice some low end extension you might find something a bit more efficient. Look up Hoffman's iron law as there's no free lunch.

http://www.bcae1.com/spboxad3.htm

[edgecreek]

Hi Curtis,
You may want to post this question in the Pro Audio forum as well. I'm sure you will get great information here; they may have folks more versed in the specifics you need.
What kind of performance are you doing?
How low do you need to be able to output? What is the approximate volume of the cabinet? This will help determine the driver choice.
An interesting project. Good luck.
Jim

[NickJ]

One question you raised is whether or not you would need to get a new tweeter. If you do get a more efficient woofer it will emphasize mid-bass past where it is right now. Most tweeters are more efficient to start with, but they assumedly took that into account when designing the system and probably have some sort of pad on the tweeter. There are a couple of cases I have seen where people are able to improve the sound of some gear with a drop in part, but usually it doesn't work to well.

I think it would be better to save and build or buy a better system. Then again, this might be one of those rare cases where you could find a simple upgrade.

[mdocod]

You don't want a higher wattage speaker as they usually give less dB (sound output) per watt.

I think you're confusing Pe with Xmax... Higher Xmax reduces efficiency, higher Pe is primarily a function of material choices and can vary widely with no effect on efficiency.

Regards,
Eric