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[duane massey]

Better subs. Even upgrading to a better pair of passive subs. It's not about the power, it's about the efficiency, or a combination of the two.

[Ivan Beaver]

  but even more importantly look at SPL. #  watts will not provide you with the information you need to determine sound levels.

But even that can be VERY VERY deceiving.

You MUST ask-at what freq is that SPL determined?

In MANY cases, the peak SPL numbers are for freq that are outside (higher) than where the sub would actually be used.

So while it may be a "true number" it is COMPLETELY misleading in regards to the loudness.

Often these numbers are between 100-200Hz.

One of the more "extreme" cases I know of is a 2x18" from a "company everybody know) that has the "peak SPL" that comes from a peak in the response around 1800Hz.

Most people don't run their subs that high.

So while the number is not lying, it is NOT giving you the information you WANT it to give you.

In this particular case, the level around 60Hz was more than 10dB lower than at 1800Hz.

You MUST look at the freq response -UNPROCESSED- to get an idea of how loud it can get.

In a processed response, there may be a 10dB boost at the lower freq.  That 10dB MUST be SUBTRACTED from the peak SPL (at that freq) to get an idea of how loud the sub can get at that freq.

Simple SPL numbers are often very wrong when it comes to expected SPL.

BE CAREFUL when looking at specs. 

They may not lie-but also don't tell you the truth-in the way you want it to be told.

[Tim Weaver]

What Ivan is trying to say here is that the numbers you read in the advertising schlock are almost completely made up.

The best way to determine if a particular speaker will work for you is to try it out. Either on a gig, or against what you already have.

I know how hard that is with the Alto as nobody seems to have them in rental stock. Sometimes you can find things like a PRX718xlf, or a QSC kw118 and use that. Then read online, first hand reviews to see how the Black would compare against those two subs.


And, Ivan, when is Danley coming out with a powered 1000 dollar sub and 600 dollar top combo to take on the SOS market? Lol

[Ivan Beaver]

And, Ivan, when is Danley coming out with a powered 1000 dollar sub and 600 dollar top combo to take on the SOS market? Lol

We will let others race to the bottom-------

[John Roberts {JR}]

I do not accept that speaker specs are "all made up" It is worth understanding that the specs are generally published by marketing types that are often not technical enough to really cheat, but their job is to present their products in the most favorable light. They will often follow other manufacturers down the same winding road of opportunistic specs.

Ivan (the last honest man in the speaker business) can shed some light on this. Speaker specs are often complicated by confounding variables, how loud for how long? how loud across how much bandwidth?, frequency response +/- how much, etc. I do not want to scare you but motivate you to try to understand where the most common wiggle room exists.

Until then it is good practice to listen to good advice from more experienced posters here. When talking about speaker they have bought, there will be some amout of rationalization, but when several say goods things about the same box, it is probably a good box.

Good luck. There is much to learn, but this isn't rocket science. BTW I wouldn't want to fly on any rocket I designed, and I don't mind letting speaker experts design speakers for me.

JR

[Don T. Williams]

Tim, I think you should get the truck!

[Mark Wilkinson]

You MUST look at the freq response -UNPROCESSED- to get an idea of how loud it can get.

Not trying to disagree with anything you were saying....

.....but for both sensitivity and max output, I wish everyone used processed specs.
....specs using band-passed pink for the intended range of operation, and stating the exact filters in place, etc.
....measured specs for both sensitivity and max output.

[Tim Weaver]

Not trying to disagree with anything you were saying....

.....but for both sensitivity and max output, I wish everyone used processed specs.
....specs using band-passed pink for the intended range of operation, and stating the exact filters in place, etc.
....measured specs for both sensitivity and max output.

A standardized frequency response "target" would be nice. Say 35-100 hz +-3db curve? The Max output rating would have to stay within the window and below a certain threshold of distortion and however many decibels you can make with XXX sub is how loud it would get.  It wouldn't matter what kind of processing or how much power it takes to get there. Either it will do it or it won't.

[Ivan Beaver]

Not trying to disagree with anything you were saying....

.....but for both sensitivity and max output, I wish everyone used processed specs.
....specs using band-passed pink for the intended range of operation, and stating the exact filters in place, etc.
....measured specs for both sensitivity and max output.

So how would you rate the following.

Do you want a simple number that is not attached to anything (let's say 130dB)  If so where did that come from?

Let's say that a speaker has a 100dB sensitivity and 1000 watt power capacity. 

That is a 30dB rise or 130dB.

HOWEVER, let's say the rated response is -3dB at 30Hz, but that includes a 10dB boost at 30Hz.

That would be 97dB at 30Hz. 

So you might "assume" that you would get a 30dB rise so 127dB at 30Hz.

HOWEVER-because you were already adding 10dB to get the -3dB at 30Hz, that means that you can only add 20dB (NOT 30dB) to the 97dB.

So NOW-the max output at 30Hz is 117dB-NOT the 127dB you might "assume"-if you don't take the processing boost into account.

You MUST dig a bit deeper to get the REAL story.

And what if you don't know how much processing was added?  Was it 3dB or 15dB?

Does the speaker exceed xmax at those freq with boost?

All sorts of things can be hidden in the "magic processing" that does not show up until you turn the system up and find out where it "stops" putting out.

[Mark Wilkinson]

So how would you rate the following.

Do you want a simple number that is not attached to anything (let's say 130dB)  If so where did that come from?

Let's say that a speaker has a 100dB sensitivity and 1000 watt power capacity. 

That is a 30dB rise or 130dB.

HOWEVER, let's say the rated response is -3dB at 30Hz, but that includes a 10dB boost at 30Hz.

That would be 97dB at 30Hz. 

So you might "assume" that you would get a 30dB rise so 127dB at 30Hz.

HOWEVER-because you were already adding 10dB to get the -3dB at 30Hz, that means that you can only add 20dB (NOT 30dB) to the 97dB.

So NOW-the max output at 30Hz is 117dB-NOT the 127dB you might "assume"-if you don't take the processing boost into account.

You MUST dig a bit deeper to get the REAL story.

And what if you don't know how much processing was added?  Was it 3dB or 15dB?

Does the speaker exceed xmax at those freq with boost?

All sorts of things can be hidden in the "magic processing" that does not show up until you turn the system up and find out where it "stops" putting out.

With all due respect, I think it gets alot easier than your example, if we just stick to measurements for discussing sensitivity and max output.
Besides, the second we start talking wattage ratings to determine max output, it's becomes all bogus anyway...

For sensitivity, I could live with a single number...if that number was simply SPL vs a reference voltage (like you guys do).....and if that voltage and SPL were time-averaged to get a stable look while using band limited pink. I'd also ask for measured average current over the same period, for a more meaningful nominal impedance spec.

I'd say let the manufacturer choose whatever bandpass he wants to claim for the intended use....just discose the exact HP and LP filters being used.
This would help keep the low end f-3 more realistic, as using an unobtainable f-3 would lower the measured SPL vs the reference voltage. The sensitivity spec would suffer from claiming too low a response.
If a manufacturer wants to include peaking or other filters in their processing, fine, just disclose them.
But even if they weren't disclosed, if sensitivity was simply measured as proposed,  a 10db boost like you mentioned, would require a corresponding drop in overall voltage level to keep the reference voltage intact. So again, the sensitivity spec would suffer, once again forcing the manufacturer to be a little more circumspect.

Max output could be measured using the exact same filters in place, for both short term max output and AES time ratings. 
Just measure average voltage, current, and SPL, ....cold, and then at the end of long term time trials. 
Comparing short term cold and AES, would give us real world compression too.

Take this relatively simple method for measuring both sensitivity and max output, and throw in raw magnitude and phase curves, along with cold and hot impedance sweeps....and damn, we'd have some really useful disclosure huh?  Who knows, distortion could possibly even make it to the specification's table someday if we could get off to a new start

[ProSoundWeb Community]