IB Square Wave Response

[thecrypt]

Hi. I am curious as to the square wave response of an IB with single-digit (or LOWER) capability, specifically at 10-15hz. I am interested to see how the flat top of the wave looks.

If it's not too hard for someone to do this (or if you wonder yourself) that has equipment capable of allowing measuring all the way to the DC level (maybe post-processing is possible to negate the effects of capacitors in the signal chain?), feel free to post something. Thanks.

[ThomasW]

If you want to risk the destruction of your equipment by testing with square waves go right ahead, but don't ask others to do this for you.

Given the passband where subs operate it's highly unlikely that DC blocking caps have a negative impact on sound quality

[thecrypt]

Hello. I did not intend to encourage dangerous behavior. I am not sure if you are referring to the DC part of a square wave or the upper frequencies, but I forgot to mention that the square wave should be low passed somewhere around 200hz to cut out the high frequencies.

I have tried this on my system, BUT due to a mere 25hz capability I get so-so results.

I saw somewhere they do a similar test for headphones and wondered how it might work with something like an IB. It would be interesting for me to see how something that can handle extremely low frequencies would handle a DC signal in a practical experiment. Theoretically, it should act as an acoustic high-pass filter, correct? (unless it's one of those rotary woofers).

Are you saying that small signal quasi-square wave testing can damage equipment?

I have played electronic music with a strong square wave component at high levels without any issue.

If you can explain what I could be forgetting about square waves, I might find it enlightening.

[maxserg]

Personally I don't think that square waves could damage the subs at the condition that it is of low power test. Don't put 400 watts in that test, do it with 3 to 5 watts!

I have a Crown DC-300 that is a good battery charger! it really goes to dc with proper test equipment:P

By experience I could say: don't do it for a long period and with low power. If you can measure at low level that's fine but don't shake the room with this test cause you'll fry your drivers.

When a voice coil has a good amount of power when it is not moving the heat builds up because it is in still position, no air is moving around and then the insulation between the coil wires melt then you get a burnt coil!

So do it if you want but at low level

But if you want to change your drivers go full level then maybe you'll see smoke coming from your subs

[robaudio]

2 hz square wave of rotary subwoofer!!

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[FOH]

Looks more like 3.5hz, but whatever,...what's the point?

[maxserg]

Doesn't look musical to me. Do you like clicking noise 3 times per second?

[robaudio]

Apr 27, 2011 9:39:27 GMT -7 FOH said:

Looks more like 3.5hz, but whatever,...what's the point?

The rotary subwoofer has essentially perfect bass transient response and the square
wave response shows this. Conventional subwoofers have reactances which make it
inherently impossible for them to achieve correct bass transient response. Having
response down to dc is one of the reasons the rotary subwoofer has perfect transient
response, not to mention the fact that it does not have any excursion limits. Conventional subwoofers reach there limit very quick as frequency goes down and
will bottom out and distortion sets in. Listening to recordings, with thunder claps or
cannons with the rotary subwoofer is awesome. All this with just 200 watts of power
which pitches the blades. So the point is that the rotary subwoofer produces perfect
transient response, which the square wave proves, matches the impedance of the air,
like horn speakers do, and gives one extremely exciting and realistic very low bass
reproduction.