Best sounding combination for Altec 416A

[DNV47]

You mentioned the 755A driver and that could be a clue that maybe your not sure what your looking for in speaker sonics or even type. Electrostat, high efficiency bass reflex, acoustic suspenison, etc.

The 755A or B are usually sought after by people that believe one full range speaker without a crossover sounds better and the popular mounting is an open baffle.

Open Baffle

These drivers can sound very nice in the mids but they lack lower bass and upper treble so they really aren't "full range" but if the mids are the most important thing to you, they work.
They aren't very efficient and I think it would be a mistake to try and use them along with the much more efficient Altec or JBL drivers because of level matching problems. (SPL)
A pair of older Electro Voice 8 inch cones like the SP8 or LS8 would probably work better and I liked them better than the 755B's I once had.

There's also a question of dynamics or impact. The 755's do not have the same impact as the Altec drivers and they don't sound as fast or sharp. You used the word "delicate" and I'd say the 755's are more delicate sounding than Altec Drivers but that would apply to the EV drivers too.

If you want to use the 416A's, I'd follow Voice of the Theaters advice and mate them with 902's or even one of the 802's with 811 horns and a model 19 xover.
BMS is also a popular HF driver and I think it might be the 4550 that some people have used with Altec woofers and it's high frequency response goes beyond the Altec but I don't know if it sounds like an Altec driver or not.
The Altec 806 driver will work but the high frequency extension isn't good.

The model 19 xover is an equalizer of sorts and it tames the mids while boosting the highs and it's very effective but if you have 16 ohm woofers the values of the components in the xover will have to be adjusted for best results as Voice already said.

The 19's can sound very smooth and life like but there is an element of punchy dynamics present and I wonder if you wouldn't be happy with a pair of Altec or GPA 604's?

I once had an early 1950's Altec 604 and I can see why they are loved so much but I prefer the more full and dynamic sound sound of the Model 19's.

[GM]

The 19's can sound very smooth and life like but there is an element of punchy dynamics present.........

Tuning the cab lower will smooth them out further for a 'tighter'/'faster', more HIFI response similar to what one gets if loading them with 515Bs.

GM

[mekr]

Thanks for the information,a friend suggested to go for 360 litre Onken cabinet of 25mm birch ply with 511 horns and HF driver

[mekr]

i shall certainly post the pictures when the project is complete

[voice of the theater]

Thanks for the information,a friend suggested to go for 360 litre Onken cabinet of 25mm birch ply with 511 horns and HF driver

I'm not familiar with the 360 liter Onken cabinet (but I'm sure there are people here on this board who are--who may chime in about that cabinet). One thing I can say as far as your potential choice of 511 horns--there is a possible advantage to using 511 horns in a system with 416's. Some Altec fans like using a 500hz crossover with 15 inch woofers so that the crossover point in your system is below most of the vocal/mid range. That way, you're not asking 15" woofers to cover frequencies up to 1200 or 800 hz, they're covering the sound below 500 hz and the bulk of the vocal/mid range is above the crossover point. You just have to be careful that many H.F. drivers can't be pushed too hard (with too much power) without damage at the 500 hz range--this may not be much of an issue for home listening volume levels but definitely a consideration when using a horn loaded system with a 500 hz crossover for P.A. use. Has your friend recommended a H.F. driver or a crossover or are you still looking for suggestions there as well?

[mekr]

Yes He recommended 802 Alinico from GPA ,I had about 8 months back bought Altec 604A but had to cancel the deal as i read the sound being used in recording studios and may be analytical as i did not know about the sound

[GM]

You just have to be careful that many H.F. drivers can't be pushed too hard (with too much power) without damage at the 500 hz range--this may not be much of an issue for home listening volume levels...........

IME, for low distortion/high SQ 500 Hz XO apps requires either a large format series (2xx) or dual small format drivers (80x) otherwise the latter can sound a bit strident if not driven with a ~matching impedance tube amp.

For a 511 app then, I recommend pre-Tangerine phase plug 802 series drivers if single and you can get by with the 804/806 series if dual, with the better 802-8G, 902 or 909 series being for higher XO points due to their slightly upward shifted BW to cover the higher BW that the digital age offers.

Its main advantage over the 811 for higher XO points then is its greater directivity control over a wider BW, a plus in high aspect ratio rooms or apps where the listening distance forces the speakers into the corners to get decent stereo separation.

GM

[mekr]

Yes i was suggested 1200 HZ Xover

[GM]

Thanks for the information,a friend suggested to go for 360 litre Onken cabinet..........

Again, fine for an original 416A, but big as it is, maybe ideally too small for a GPA re-cone and your only tuning option is to damp or completely block off one or more of its multiple vents. WRT to a high SQ app in general, some of mine and others thoughts here: onken Onken w or A7 or Valencia - diyAudio

GM