Neo8 arrays. What is a better way to lift falling...?

[Lito]

Hi,

What is a better way of solving the falling response of this array at 15K. Electronically equalize or add another Tweeter to cover this range. I have a pair of Raven 1. Will it be good to add this tweeter? TIA

Lito

[GRollins]

I have the RD-75s. Not quite the same, but they have a similar characteristic. I bought the RD-75s knowing that the top end would be less than stellar. In addition, I had a card up my sleeve. I use the ribbon tweeters from my old Magneplanar Tympani IVs to handle anything above 5kHz. First order (i.e. 6 dB/oct) crossover. Works like a charm.
You can eq if you want, but I generally avoid that sort of thing when I can. If you've already got Ravens on hand, try them out.

Grey

[Danny]

How many are being used in the array?

Do you have measurement taking capabilities?

[Lito]

Hi Danny,

8 Neo 8 are used per array. Yes, I have measurement capability.

Lito

[Danny]

8 Neo 8 are used per array. Yes, I have measurement capability.

Great.

I have used eight of them per side in our Alpha LS kit.

http://www.gr-research.com/AlphaLS/Alpha.htm

I am sure you have noticed that the comb filtering effect of using that many of them in a line will reverse the rising slope effect you get when measuring a single unit.

So, no notch filter is needed to counter act the peak that you get at about 15kHz with a single unit.

As frequency decreases there is less comb filtering effect from the multiple units than there is in the high frequencies. The result is a pretty smooth response using eight units.

You might also play with the amount of air space behind them. I settled on a cavity with about 3" of depth.

On the issue of the highs...

Don't worry about it. Some of it is a function of distance. The further away you listen or measure, the less the roll off in the highs.

Plus, it only slightly rolls off in 1/2 of the top octave, but extends to 40kHz pretty smooth after that.

There is no fundamentals up there, only upper level harmonics.

I have yet to have anyone listen to the Alpha LS and feel that the highs had any loss of extension, and hundreds of people have heard them.

Adding a tweeter, especially a single tweeter to add addition highs would not be recommended.

For one, you have a line source of Neo 8's. They loose 3db in output for ever doubling of distance.

A single tweeter would loose 6db for ever doubling of distance.

So if you matched the output at 1 meter then at 4 meters it would 12 db down. That is more than the Neo's are down by about 4db.

Also, crossing them over to a tweeter at a high frequency will require a steeper crossover than you could put on it to keep it from causing off axis suck outs as vertical listening height or measuring height changes. You will cause greater dips in the octave below the crossover point with slight changes in vertical locations. This is far worse than what you have now.