Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Chris Grimshaw]

I don't believe for one second that Yamaha is getting a real 139db out of the DZR

They'll do it. Once. At a carefully chosen frequency. It might catch fire.

I heard about another Manufacturer You've Heard Of's max.SPL tests, and it went like this: line up 10x speakers, and a Very Large Amplifier. Hit each speaker in turn with larger and larger signals, while continually tracking SPL. Destroying the speakers was mandatory - if it hasn't failed, you haven't got everything out of it yet.
After going through all 10, whatever the loudest sound at the mic was, is what goes in the brochure.


Chris

[Luke Geis]

^^^^^^

I can believe that and have a pretty good idea of who you're referring to

[Caleb Dueck]

^^^^^^

I can believe that and have a pretty good idea of who you're referring to

I have an idea as well.  Any way we can post a list of manufacturers and an approximate "take off X dB from published" to shame the guilty? 

[MikeHarris]

It depends on the powered speaker (e.g. Meyer makes optional rain hoods for their speakers' amplifier modules for exactly this use-case).

-Russ

Martin makes rain hoods for  CDDLive...as does RCF for the HDL

[Chris Grimshaw]

I have an idea as well.  Any way we can post a list of manufacturers and an approximate "take off X dB from published" to shame the guilty?

Sounds fun.

Meyer's M-Noise seems like a useful test signal, and the protocols they built around it makes a lot of sense. Apparently they enjoyed the article published in 2017.


All we need now is a selection of boxes from each popular manufacturer, a high-end test system, somewhere we can make a lot of noise, and someone who's happy to run the thing.

Chris

[Dave Guilford]

Martin makes rain hoods for  CDDLive...as does RCF for the HDL

How hard could it be to make my own?  Clear and thick vinyl. Put it in place

[Luke Geis]

My way of coming to real-world numbers is to take the peak number and reduce it by -16db.

My math on it assumes that the peak number is the number you can get only for the instant that it's created. So factoring continuous power as opposed to peak you would reduce the peak number by -6db. This does not take into account crest factor. Most live music has a crest factor of around -15db. I give a wee bit back since canned music is about a -5db CF or you could say I take away -10db from the theoretical continuous output to come to what I feel is an actual achievable number. This does not account for any inverse square law loss, so be sure to reduce that from your calculations as well.

With my recipe, a speaker that says it's capable of a 136db peak should be able to hit a real-world output of about 120db at the 1-meter mark. In most cases where I have measured at distance and calculated back to 1 meter, my recipe has been very close to true. Give or take a few dB.

Using this method I can tell pretty much right away if a speaker will or will not work at a given venue or if I will need to increase the speaker count to use for delay lines.

[ProSoundWeb Community]