A Question on Subwoofer Spec

[umbucker]

I have just purchased a Velodyne SPL 1000 Ulta Subwoofer with DSP. I have looked into the spec and read the manual which explains the 4 presents and explains which source material best suits which preset.

The Manual also explains each preset in terms of its EQ settings, and also shows the SUBSONIC FILTER. In Rock this is set at 28Hz in Movies 25HZ and in Games 34Hz. It is only Jazz setting which has no subsonic filter and goes down to the subs far reaches of 15Hz

Now this is what I dont understand, this, as well as most subwoofers on the market show off as much as they can to how deep they can go - I would say it is one of the main things to look at when buying a new sub. So why would Velodyne think I would only want anything below 25 Hz If I was listening to Jazz ? Why on earth would it roll off frequencies at 25Hz for Movies ??

Unless I have interprested this all wrong, and the subsonic filter is something different ?

 

[martin morecroft]

The 1000-Ultra will not get down to 15Hz with any useful output. That is an in room figure. Best to look at the +/- 3dB figues which are realistic. The subsonic filter is there to protect the sub and stop it trying to do something it cannot do. I would need to check about the setting for music.

 

[martin morecroft]

None of the preset filters are "brickwall." They are noted as a guideline as to where the roll-off starts. Personally I use Jazz setting for all media. I have checked this out and the subsonic filter starts to roll off at 15Hz on this pre-set. The other pre-sets use different curves to appeal to varying taste. Jazz is the most pure setting in terms of boost and cut to shape the curve.

 

[Frank Harvey]

I don't understand why it has a 'filter' for different program material. Whatever you're listening to or watching, you want it to go as deep as it comfortably can, and leave it to the source material to denote how low it will go. Game soundtracks can be every bit as good as movie soundtracks nowadays, so why they have set that to roll off at 34 Hz I'll never know. Unless you have to select one of those filters, I'd ignore them and not use them. The more processing and filtering added to anything, the more it can negatively affect the source material. A bit of room EQ is fine for a sub as it will more than likely be needed, but extra filters aren't.

 

[martin morecroft]

You are partially correct. In an ideal world you should let the sub design set the boundaries of bandwidth. However, for reliability and longevity it makes no sense to let an 8" sub have a go at infrasound. It will try and hopefully its protection circuits will save it from damage. While trying to perform the impossible it will impare its performance in the part of the band that it was designed to cover. Filters are a compromise, hence the reason why the Velodyne Ultra has a setting with no filters at all. The presets are also there to provide some balanced curves that modify the sound in a standard domestic environment. There is no such thing so it is a bit hit and miss - some people like it though. Personally I use the Jazz setting which is pure.