Looking to run a true 5HZ signal to my Sub woofers but think my anthem receiver will Bottle neck this.

j_garcia

j_garcia

Audioholic Jedi
Curious, just how much better picture quality did the later versions actually bring?
BD not so much, but the UHD definitely looks far better than it ever has. Seems it was rescanned from the original print and cleaned up.

The Atmos mix is better as well, except that they did not bring back the deep bass.
 
m. zillch

m. zillch

Full Audioholic
Thank you so much for sharing this. It does at least confirm that there is no hard cut at 15 hz, using ARC genisys, which is awesome.
I didn't watch the complete video, but by my read/analysis of the image at 18m09s showing before vs. after curves in this video,
not only does ARC genisys room correction (at least in this AM90) not work below ~15Hz, it also looks to have already applied a steep reduction in output by 15Hz as well.

This would not surprise me because I'd assume they know what they are doing and from my perspective reproducing ultrasonic and infrasonic content in audio not only is unproductive to what we hear, even with ultrasonic and infrasonic capable playback systems playing content containing ultrasonic and infrasonic sound, but it is detrimental to the sound quality of the important audible range content we do care about, for several reasons including the potential creation of intermodulation distortion. [Details and backing references upon request.]

Also to reiterate what I wrote earlier, for reliable results evaluating/measuring what electronics like ARC genisis do should ideally be done directly (electrically) not be done acoustically after additionally passing the signal through the modifications of power amps, loudspeakers/subs, room acoustics, varying mic selections/placements/aimings, in non-anechoic (non-soundproof) rooms potentially contaminated with background sounds which we may not be consciously aware of (because they may fall below our detection thresholds for those frequencies but not necessarily that of the test mic's).
 
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A

Allen Vos

Junior Audioholic
Here is the model of the driver under discussion.

I have done this very carefully. The program used was Bass Box Pro. This is a highly regarded program and used by many professional designers.

It basically shows what I had surmised from my now 72 years of speaker designing and building spekers.

First of all, it seems to be a very capable driver, but it can not perform miracles and has to abide by natures physical laws.

So the highlights.

Bass Box pro, as expected indicates this driver is suitable for sealed application only.

The optimal sealed volume is 8.28 cu.ft. with heavy fill.

The native F3 is as expected about an octave above Fs. which is 39.54 Hz, which rounding it off is 40 Hz, exactly what I estimated. So the driver rolls of at 12 db. per octave as all sealed designs do. Therefore it is -12 db. at 20 Hz as expected. So a boost of 12 db. per octave needs to be applies below 40 Hz.

Now this driver has good excursion limits, but it starts to head towards xmax below 20 Hz as you would expect. At 20 Hz the driver will tolerate 200 watts of power, below that it starts to exceed X-max, by 15 Hz the driver is running out of cone displacement and output is falling off and the driver risking damage. So as I suspected the driver needs high passing at 20 Hz, which is its effective lower frequency limit, as I suspected.

So, in essence this is a very capable sub driver, but it does not perform the miracle of defying the laws of physics. However with capable amplification and proper high and low pass filter settings, it appears to be a very capable LF driver, which for its cost and size it should be.

I hope this puts an end to the nonsense that has appeared on this thread and the insults from the OP. I stand by this model unreservedly, and it reveals the full facts of the situation.
I appreciate your feedback and experience, but I have a few questions about your findings as they differ significantly from my own modeling.
  • Xmax Discrepancy: The manufacturer's website lists Xmax at 29mm, but your data shows 34mm. Could there be a typo in your parameters? One small key difference might be the enclosure volume. My net internal volume is 6.2 cubic feet (6.6 gross minus 0.4 for driver displacement and bracing), whereas your model utilizes an 8.2 cubic foot enclosure. This larger volume somewhat explains why your model shows higher excursion.

  • Graph Scale Contradiction: Your cone excursion graph cuts off at 18mm, though it should scale to at least 29mm or 34mm based on your data. Because the graph stops there, it shows 18mm of excursion at 6 Hz, which directly contradicts your claim that the driver runs out of excursion at 15 Hz.
For comparison, I modeled this in WinISD with 1,200 watts of input power and triple-checked the data. My graph shows 19mm of excursion at 20 Hz and 10 Hz, peaking at 23mm at 5 Hz.
Additionally, the designer confirmed this sub can play down to DC (0 Hz). I have also personally verified four of these units playing down to 10 Hz via a calibrated microphone and SPL graph. Given these gaps, I respectfully disagree with your conclusions and would love to figure out why our models don't match.
FTW-21 Cone Excursion Graph.jpg
 
A

Allen Vos

Junior Audioholic
I didn't watch the complete video, but by my read/analysis of the image at 18m09s showing before vs. after curves in this video:
not only does ARC genisys (at least in this AM90) room correction not work below ~15Hz, it also looks to have already applied a steep reduction in output by 15Hz as well.

This would not surprise me because I'd assume they know what they are doing and from my perspective reproducing ultrasonic and infrasonic content in audio not only is unproductive to what we hear, even with ultrasonic and infrasonic capable playback systems playing content containing ultrasonic and infrasonic sound, but it is detrimental to the sound quality of the important audible range content we do care about, for several reasons including the potential creation of intermodulation distortion. [Details and backing references upon request.]

Also to reiterate what I wrote earlier, for reliable results evaluating/measuring what electronics like ARC genisis do should ideally be done directly (electrically) not be done acoustically after additionally passing the signal through the modifications of power amps, loudspeakers/subs, room acoustics, varying mic selections/placements/aimings, in non-anechoic (non-soundproof) rooms potentially contaminated with background sounds which we may not be consciously aware of (because they may fall below our detection thresholds for those frequencies but not necessarily that of the test mic's).
The one thing we all agree on is that ARC correction stops at 15 Hz. But I'm getting conflicting info on whether Anthem receivers will actually pass frequencies below 15 Hz when ARC is turned on. Some guys say yes, but others—including a tech from Anthem—say it cuts it off.
Everyone does seem to agree on one thing though: with ARC turned off, the receiver will pass a 5 Hz signal with no problem. Honestly, I'm just going to test it both ways myself once everything is hooked up.
 
m. zillch

m. zillch

Full Audioholic
Everyone does seem to agree on one thing though: with ARC turned off, the receiver will pass a 5 Hz signal with no problem.
I searched but was unable to find any source which backs that up based on electrical (not inherently flawed acoustical) measurements. Not that I'm claiming I have evidence to the contrary.

I have seen measurements of the main unfiltered outputs which seem solid to 10Hz, at least without ARC, which is only an octave away from 5Hz.
 
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