High Efficiency Speaker Asylum: Re: Best 6.5â€ 95 dB mid by EGeddes

First, contrary to other posters I applaud your ratioanl and scientific approach to this. Just buy them and listen is a bit too uncontrolled for me. You may as well role dice.

I may have misled you however in that I recently switched to the B&C 6NDL38, the Neo model with a flux ring. This driver truely is well controlled. Its a little less sensitive than the 6MD38, and more expensive, but my calculations say that its MAX_SPL would only be about 3 dB lower which is not a big issue. I don't care too much about sensitivity (I don't use tubes) but I do care about MAX_SPL because in a home theater thats a big issue. At about 113 dB SPL max the 6NDL38 suites the task. I may add a tweeter to it and I may not. I am not convinced that HF from a surround channel are important. In fact a rolled off high end gives the subjective impression of the sound being father away. In a small HT this is exactly what I want.

I also meant to make another point. I don't hold a lot of credance to the axial response. If its real bad then its hard to see how the speaker could be any good, but being real flat does not mean that the speaker has good directional control or having some small axial aberations does not mean that the polar response is not excellent. You see the axial response is a rather unique place to make measurements - its equal distance from all points on the driver. But more importantly in a power response calculation it is the least significant point. Thats because in the power response the points are weighted by sin(theta), which is zero for the axial position. One does not actually use a value of zero, but in the power calculation the axial point has the lowest weighting of any of the points.

I will never make a judgement about a driver until I see its polar response. Then I can tell how well controlled and designed it is and how well its likely to work in a system.

Axial response is way too over emphasized.

Earl Geddes

Re: Best 6.5â€ 95 dB mid

Re: Best 6.5â€ 95 dB mid