Faking subs electronically for tests?

[Gregory]

Whilst wallpaper stripping this afternoon, I was pondering the free beer thread, EQing on subs, and wondering whether it could be taken further to avoid the sub-selection catch 22. Specifically, it would be good to demo several subs in selecting, including location (to see if the vast box needs to be dead centre in the room or similar ), to be able to flick between them, and also to work out whether the cost of EQing was worth it.

EQing as it stands is used AFAIK principally to flatten the response - esp room resonance - and to add a house curve as desired. But, the same basic method could also be used to simulate the response that different subs would give 'naturally'. Effectively you EQ not to flat/house curve, but to the same basic response curve of the desired unit. This would make it possible to work out if there is a system whose response curve fits well 'naturally' with your room, so allowing use with little/no EQing on a BAU basis (for those who don't want to burn money on a BFD or similar). You could also do both an EQ and de-EQ to simulate an EQ'd system other than the one you have.

The intent would be to have a small system that could be couriered cheaply, but that included everything needed to check out your options in your own house, on your own system, with your own ears. Potentially using a computer already in the house to do handle the measurements (a la REW), but then going further in taking a test music or DVD file and doing the audio wrangling off-line so that it is highly accurate, and doesn't need a BFD equivalent to be sent out as well. With the right test system, this could include outputting the bass levels of a much larger driver, but just not at the same level (same audio wrangling could serve as driver protection against being over-driven) - so keeping a test system that could be couriered cheaply quite do-able.

Right. back to the wallpaper

Cheers

Greg

[russ.will]

It's an interesting concept, but there's one problem that immediately springs to mind.

With a sub small enough to be practical, you couldn't replicate the effect a larger subs sheer dimensions have on it's integration with the room.

The ports on any of the big SVSs for instance, are the best part of a couple of feet from the centre of the driver and on entirely different faces of the sub. This has an impact on the interaction with the room and cannot be replicated by a sub without this physical make up.

In this respect alone, to replicate the sub in the the room requires that sub to be in the room.

Russell

[Gregory]

Fair, but if the alternative is no check at all pre-purchase, I wonder if that will be a huge issue? Under any circumstance it would only serve to simulate the real driver. Alternatively, given that most ported sub's seem to have the port outlets on one side, it might be possible to properly simulate that as well with another driver (though it would add to the cost/hassle, obviously).

What is going through my mind is that given electronic fettling, repeatability is more important than linearity - that can be faked.