Is it me or I hallucinate? (1 Viewer)

[ClaudeL]

I was comparing a Maelstrom and Tumult solution with WinISD. I got very astonished to see that:

-Maelstrom, 5 cubic ft tuned at 22 Hz with 720W (most likely required to reach maximum excursion) of power
-Tumult, 5 cubic ft tuned at 20 Hz with 1600W of power

The Maelstrom is 1 dB louder at 40 Hz, 2 dB louder at 50 Hz, 3dB louder at 60 Hz than the Tumult!!!!!! So the Maelstrom can have more mid-bass punch and IMPACT than the Tumult???

 

[Chris Carswell]

Check your #'s again......

 

[ClaudeL]

Oh well... I did! Whats wrong? I would like to know

A 5 cubic ft maelstrom tuned to 22 hz with 720W of power have an excursion peak of 26mm(pp) at 38 Hz. So 720W should be nice for that woofer if we want the most of it without bottoming it out, except where the woofer begins to roll off in very low frequencies.

A 5 cubic ft Tumult tuned to 20 Hz with 1600W of power have an excursion peak of 51mm(pp) at 28 Hz. So I think that 1600W of power wouldnt be enough to make the Tumult reach its maximum linear excursion.

So when you have both of these box with the correct power in WinISD Pro, select the SPL graph and you will see that the Maelstrom will be superior above 40 Hz vs the Tumult (in SPL).

Any comments? Am I wrong there? If this is all true, then the Maelstrom is a damn good chest kicker for the price!

 

[Chris Tsutsui]

I think that the sound quality of the Tumult and distortion figures will be far better than the Maelstrom at those high excursions.

It may be able to play the frequencies loud, but would you enjoy hearing it?

 

[michael-e]

numbers are one thing

actual output,another.

which speaker would be more linear? how can you know/

what about compression? that could make the difference in output-but you dont know those-because only PRO manufacturers usualy list those..

also compare between programs to ensure accuracy,i dont totally trust winisd for all things.

 

[Patrick Sun]

I recommend downloading the LspCAD program that Adire provides for their drivers on their website. WinISD is decent for getting the length of tube for a particular tuning frequency, but I also don't lend much credence to the rest of their take on projected output/frequency response.

 

[ClaudeL]

But the problem is that LspCad dosn't have the Tumult woofer... :frowning: Also, I figured out that the Maelstrom woofer, when it is doing 26mm of Xmax both way, wouldnt bottom out or clap. I know it wouldnt sound as clean as the Tumult in extreme excursion but still, when the bass is loud, you would have to be quite close to the woofer to detect any real distress from it.

So with all these numbers, I think again that the Maelstrom is still better in the mid-bass region (pure SPL not sound quality). Please correct me if Im wrong and if WinISD PRO isnt that accurate, how can I know if a woofer is better than another for pure SPL? By looking only at its Vd? I dont think so...

 

[Jack Gilvey]

The Tumult has more displacement, and will have more output at a given frequency. The Maelstrom is more efficient.

I know it wouldnt sound as clean as the Tumult in extreme excursion but still, when the bass is loud, you would have to be quite close to the woofer to detect any real distress from it.

Nope. We're not talking about mechanical distress (bottoming), but THD.

 

[Patrick Sun]

Email Dan Wiggins or Adire and ask them to add the Tumult to the driver database in their version of LspCAD.

 

[Justin Ward]

Also, I figured out that the Maelstrom woofer, when it is doing 26mm of Xmax both way, wouldnt bottom out or clap.

Isn't it only 26mm total? Maybe this is the problem?

 

[ClaudeL]

numbers are one thing... actual output,another.

Sure, if we consider THD. But is it STILL true to say that the Maelstrom will give you more mid-bass impact (more SPL above 40 Hz) than the Tumult WITHOUT considering THD? Because as far as I can tell, WinISD Pro can only show you SPL without considering the THD of each woofer.

Are you telling me all that WinISD Pro isnt a good program to tell you how different woofers can compare from each other in specific enclosure sizes? If this is the case, tell me how the average people who wish to build a DIY subwoofer can know how differents woofers can compare in different enclosures before building a definitive subwoofer.

 

[Jack Gilvey]

As I said, the Maelstrom is (much)more efficient, so it can make more sound with a given amount of power applied. At the power levels and alignments you've chosen, the Maelstrom is louder in the midbass. Ultimately, the potential output of the Tumult is higher...it can move more air. Nothing revelatory. Certainly, Maelstrom is an excellent woofer and a good choice for instances where the deepest bass isn't required and more moderate power is available.

 

[ClaudeL]

Thank you Jack for your answer!

Im wondering now if WinISD Pro is still a very good program to model some subs. I say this because I saw some people mentionning that it is not so accurate. Is LaspCAD that more accurate?

 

[Jack Gilvey]

WinISD Pro is much better than WinISD. Its results seem to agree with Unibox, which is reputedly very accurate. These programs are most useful as tools for coming up with designs, and not as infallible predictors of final results.

 

[ClaudeL]

Justly, I use WinISD Pro. I dont know why people would use the none Pro version if the Pro is already free I think that I understand very well now the concept of all this comparison by taking care of the THD of each woofer... I took care of it before (THD), but I just wanted to know if I was right about the max SPL. I knew the Tumult was still the winner in clean bass output

Thank you for lighting me up with your answers

 

[Jeremy Stockwell]

Jack often "lights people up" with his answers, for good or ill. Right, Jack?

JKS

 

[Jack Gilvey]

Yep, either way's ok with me.

 

[ClaudeL]