Rythmik F8

[RythmikAudio]

For passive speaker, the frequency reponse looks the same as the max SPL response because the amplifer has no EQ and we just scale them up (add 20db for 100WRMS). But all subs have EQ to get the bass extension on the FR plot. Exactly where the max SPL is going to be on each frequency is something you don't find unless you go to sites like data-bass.com. I rememeber several years ago, a customer ask one compnay of the T/S parameters of their drivers in their sub. The support guy replied they are proprietary as if the T/S parameters garner secretes lead to their better output. Everyone nowadays has access to subwoofer simulators. A few thing affects the max SPL customers should keep in mind: 1) enclosure size, 2) power amp output rating (as long as manufacturers dont inflate it), and 3) compliance of driver (some drivers have very stiff rubber surround and those takes more power to move). So our F12 output will be similar SB-2000 if not better. So 1db here and there should not be the deal breaker. Customers bought into our subs don't nick and dime max SPL output. That is not our selling point. Our selling point is we get comparable output as our competitors and yet we offer audibly better sound quality.

Now for transient response. Transient response is measured by time domain impulse response. The more filtering you incorporate, the more so-called group delay the subwoofer will get (and more ringing in the transient response). SVS has incorporate high order filtering to that it is less trouble for the manufacturers. We do understand the importance of low group delay and we make the rumble filter an defeatable opton. In addition, we publish the phase response of our subs. It has 90 degrees phase shift at around 20hz. No other subwoofer comes this low. The result is a fast transient response. Subwoofers with excessive group delay and filtering will sound "boomy" or less natural. If we compare the reproduced sound with the sound that we hear every day, one big difference is our real-world sound does not have filtering and therefore no bandwidth limitation. Subwoofers on the other hand does have bass extensin limitation and once it is limited to 20hz, it is not going to get better even if we use 100 of those. So our goal is produce a sub with least amount of phase shift and as flat as possible. If one sub is not enough, two will work better :-)

So our plot is to show customers both the amplitude and phase response of a particular model. In practice, I will challenge any company publish max SPL curve with the question if that is measured in snow or in desert? or is it measured in cold start or after 2 hours of pub like playing? This is becasue voice coil temperature is a big factor.