Run in time for new GPA 902's? Also, remove throat cover?

**atilsley** · April 9th, 2013, 07:05 AM

New 902's from GPA...very nicely made and packed.

Any thing special about running these in?

Also, what is the opinion regarding removing the cloth over the throat? Worth the risk? The new GPA driver has a criss-cross weave which is different to the original Altec mesh/film.

Kindly

Andrew

**atilsley** · April 9th, 2013, 08:08 AM

Pic added of original 902 (left) vs GPA 902.

**Alien_Shore** · April 9th, 2013, 12:47 PM

I like the looks of the coarser bug screen on the new one; looks like it would possibly be more transparent? Did it come with a spec sheet? Is the flux density the same on the new ones?

**atilsley** · April 10th, 2013, 01:19 AM

Originally Posted by Alien_Shore

I like the looks of the coarser bug screen on the new one; looks like it would possibly be more transparent? Did it come with a spec sheet? Is the flux density the same on the new ones?

I can't pick an audible difference between the two drivers. The pic is from me, not GPA. I'm waiting to hear back from Bill re any advice on run-in...but I suspect, as GM suggests, it's a non issue. Certainly, the new drivers sounded wonderful from the get go.

GM, others, I know I've asked this in different ways before...but, using lay terms/plain language, how would you describe the main audible differences between the 902 in a 511 (crossed around 1200Hz), vs a 1.4inch driver in a larger multi-cell horn, crossed lower, eg 600Hz?

The reason why I ask is that I'm always adding/changing things. I still have the opportunity of building those large open baffle wave guides with x2 416's per side...and if I did this, I'd probably want a lower xover point (eg 600Hz), then I'd use a larger mid horn and 1.4 inch driver.

I'm really enjoying the 902/511...this is the first taste of a vintage altec horn for me. I love the way the horn sounds...sort of shimmers/tingles. Sorry for my unsual way of describing it...example, good recording of steel string acoustic guitar...you can really hear the lovely texture of the steel strings. The sound stage is very large - both in width and depth.

What would I be getting different if I went for a 1003 or 805 horn in my normal domestic listening environment...?

Is there a trade-off in adding more complexity (xover, tweeter etc) with the larger format horn, vs the simpler two-way 902/416 combo...?

Thanks and regards.

Andrew

GM · April 9th, 2013, 01:01 PM

Ask GPA to be sure, but compression drivers historically were designed/built to 'hit the ground running' in a properly designed high power app. Ditto any driver really.

It turned out to be well worth the risk for me in my youth for a HIFI app, but never in a PA app. The new one is open enough that I seriously doubt there would be even a perceived difference, much less an audible one, for anyone not cursed with near dog or similar hearing acuity.

GM