Altec A7 Help needed

[CMD]

Hi All,

I have a pair of Altec A7 enclosures (with 515 bass driver, 288 high frequency driver, 1005 horn and N500-F xover). I read some years ago a paper about equalization when you use A7 in domestic audio application.

Who can help me ? Where can I find this paper.

Many Thanks to all,

Cyr-Marc

[GM]

I assume you mean this one: http://www.soundpractices.com/images/HiragaA5.pdf

GM

[CMD]

Hi GM,

Thanks for your response. I don't know if it's the good shematic or not. But, if I need to preserve the N-500F Altec xover what is the components I add to linearise/attenuated the mid frequency range. Do you have diagram for original N-500 F crossover. By comparaison I probably find where I replace some parts or where can I add some components.

Thanks

Cyr-Marc

[GM]

Hey C-M,

All I know about the N500F is what someone posted some time ago:

"250 watt system with HF shelving taps, space for optional impedance matching transformers, and additional circuitry to operate as an HF system, without any LF driver."

The N501-8A has a textbook 2nd order Butterworth with a shelving pot on the HF. To flatten a horn with them is just a matter of adding a R/C network. It seems reasonable to me that's all that's necessary for a stock A5 (what you describe) also.

WRT the Hiraga XO, from just looking at it, it's a 2nd order series XO (a good plan for HIFI apps) with what appears to be an overly elaborate notch filter, but between not being familiar with the amp it was designed to be used with and not having messed with the large format driver/multicell horns in over three decades, I can't critique it further.

Sorry I couldn't be more help,

GM

[dennis gilliam]

Yep, yours is an A5, not an A7. It can take more power than an A7, and the top end will be endless and capable of extreme loudness. I'd leave the N5XX CO alone, make up any sonic "irregularities" with a good graphic EQ.

DG

[Russellc]

GM you are correct. The author's reasoning was to push out high frequency extension by slightly depressing the mids. Perhaps this is the equalization he refered to?

Russell

[GM]

That's my assumption, but without knowing the particulars of the amp and the final FR it was designed for or C-M's amp/desired in-room response there's no way to know if the component values are even remotely close to C-M's needs.

Of course it can be built with cheap components and tweaked to suit by ear, then made with higher quality ones.

GM