Another Linkwitz Transform question

[Victor]

I am seriously looking at the Linkwitz Transform circuit for my dual Avalanche 15 sub. My intention, at least for right now, is to put 2 drivers at the opposite ends of the sealed tube. Make the tube with rectangular end-cups and place the thing horizontally in the front between my main speakers .

I have been wondering about the tube volume. I know that this topic has been discussed at length, but I still have a question, and at the risk of sounding a little dumb I will ask.

It occurred to me that the LT circuit in order to comply with energy conservation law, must lower the signal level by the amount of the boost it is applying at the lower end of the spectrum and trade this for the increased low end frequency extension. Is that in general a correct thinking here?

If this is the case, then there should not be any penalty with sound quality as long as the thermal limit of the driver is not reached, since we are not really trying to drive the driver to unacceptable levels and we have the Xmax to do that.

This is particularly true with drivers like Timult or Avalanche due to their inherent low distortion characteristics across the power levels and frequencies of operation. Would that be correct in general?

Victor

[Davey]

Victor,

The Linkwitz Transform can't do anything to increase the physical/thermal capabilities of the driver(s) in use. Its use is to merely flatten and possibly extend the usable range of the driver.

Cheers,

Davey.

[dlr]

You are correct, if I understand your question

It occurred to me that the LT circuit in order to comply with energy conservation law, must lower the signal level by the amount of the boost it is applying at the lower end of the spectrum and trade this for the increased low end frequency extension. Is that in general a correct thinking here?

If this is the case, then there should not be any penalty with sound quality as long as the thermal limit of the driver is not reached, since we are not really trying to drive the driver to unacceptable levels and we have the Xmax to do that.

This is particularly true with drivers like Timult or Avalanche due to their inherent low distortion characteristics across the power levels and frequencies of operation. Would that be correct in general?

Victor

I'm not sure why you reference energy conservation, it really just has to do with lowering the frequency extension and the impact of that. You're amplifying the signal with a particular transfer function, there's no conservation issue.

But to answer the basic question, you are correct, there won't be a sound quality penalty as long as the driver's rated Xmax is not exceeded at the listening volumes used. this is the basic tennant of the LT. This is no different than any other box tuning decisions made for a given driver.

If you use a Linkwitz Transform, just ensure that under the intended usage you do not drive it beyond its rated Xmax. I think that Linkwitz may have info at his site that will give some more insight into this.

dlr