Crossovers

[nikki1]

I have 416-8a's, 806's with 511B horns and 501 8A CO's. It has been suggested that I cross them at 800 or even 1200 instead of the 500 where they are now to get a "warmer" sound. Apparently they used 500 to make the horns project more which is fine for a theater but not so great for home.

So how about some comments. I would like to stay with Altec and note the 801 CO will X at 800 and the 1201's at 1200. My 501's are in fine shape , and if someone has a pair that they'd trade that would work out great.

Any comments or suggestions would be appreciated. I wish I knew more about what's what--------I don't know a cap from an L pad.

Lee

[valhallax]

hey lee..
im just wondering now if the 806 drivers for your horns are 8 or 16 ohm? also..there is a thread or two around here about the model nineteen crossover..

[Art J.]

I have 416-8a's, 806's with 511B horns and 501 8A CO's. It has been suggested that I cross them at 800 or even 1200 instead of the 500 where they are now to get a "warmer" sound. Apparently they used 500 to make the horns project more which is fine for a theater but not so great for home.

So how about some comments. I would like to stay with Altec and note the 801 CO will X at 800 and the 1201's at 1200. My 501's are in fine shape , and if someone has a pair that they'd trade that would work out great.

Any comments or suggestions would be appreciated. I wish I knew more about what's what--------I don't know a cap from an L pad.

Lee

From the good old school, it was agreed that 500 cycles was a good crossover point
in order to keep known passive crossover problems out of the critical voice band.
That is why the 511 and its 1/2 wavelength depth came to be. Great advantage.
If you switch it to 800 or 1200, the depth distance between drivers should be adjusted accordingly to
prevent adding phasing problems to the mix too. It would seem that any changes to the 511b
intended use will only create disadvantages. (Like, right horn for the right frequency.)

Their have been plenty of posts about the 511 tending to shout in the confines of a home environment.
Altecs solution was the 30923 slope attenuator board added to the horn circuit to tame it down for home use.
Best solution. You may have seen previous posts about it.

Altec3090430923 | Flickr - Photo Sharing!

[nikki1]

Art- Thanks for your info. Sounds as though it's the same old "if you change this then you have to change that" business and although I'd like to have the best sound I can get from what I have I've been down the "fiddle" road enough with changing things to not want to get involved in it with the speakers. If what I have was designed to function together by those who know waaay more than I then perhaps I should be smart enough to leave it the hell alone. But then looking at the schematic for the "tamer" board it wouldn't be that difficult to build and add it to the outputs and if it didn't make a solid change easy enough to remove it. I'll dwell on it. Merry Christmas-------

[GM]

Altecs solution was the 30923 slope attenuator board added to the horn circuit to tame it down for home use.
Best solution.

Personally, I believe 'best' would be driving them with a ~matching impedance SET amp to get the desired CD horn EQ , with second best being an electrical filter equivalent for a very low output impedance; though I doubt the 30923's component values designed for the more efficient 802 are going to be acceptable for the 806 due to its lower gain BW, faster HF roll off, but not aware of an 511/806 variant.

As you noted, there's still the issue of woofer/horn time alignment at least at the XO point, so for a passive solution, what's really needed is a M19 style XO that effectively has the proper CD horn EQ plus electrical offset for the longer 511 horn, but don't recall seeing one.

Seems then that for the casual DIYer, adjustable active XO/TD is the way to go with this combo.

GM

[Art J.]

Personally, I believe 'best' would be driving them with a ~matching impedance SET amp to get the desired CD horn EQ , with second best being an electrical filter equivalent for a very low output impedance; though I doubt the 30923's component values designed for the more efficient 802 are going to be acceptable for the 806 due to its lower gain BW, faster HF roll off, but not aware of an 511/806 variant.


GM

Yes, the single capacitor filter is just going to provide a general 6db slope no matter which
8 ohm driver is used. The slope probably does not match any drivers exact needs but will help.
The capacitor value will determine where the slope begins but after that, more complex designs
need to be used.

[Altec Best]

What are the exact differences WRT sound ? Between the 30904 and the 30923. I know the 30923 doesn't have the C-2 R-3 Zobel but what difference in the sound in the horn will that make.

I'll understand it much better if it can be explained in these terms.I know the 30923/30904 are attenuators for taming a High efficiency HF driver/horn for home use.

Does anyone know what the sound differences are going to be between the two attenuators 30923/30904.It says in the Altec literature that the 30904's primary function is to mate a medium efficiency woofer to a high efficiency HF driver.

http://www.lansingheritage.org/image...ome/page14.jpg

I had got some answers in a thread i started awhile back about the N1285 and the 30904 that I had received with them.Can be seen here in this thread.

http://www.hostboard.com/forums/1841508-post1.html

But I never found anything that explained what the differences were between the two attenuators just says they do the same thing so why the two variants ?

Thanks for any help on this as this has been bugging me for a bit now.Crossovers are not my strong suit.As most of you may know.

Happy Holidays !

[nikki1]

Kindly allow me to hijack my own thread and bore you guys a bit. When I was a whole lot younger and the "Hi Fi" craze first erupted I built a Klipsch cabinet, stuck a 12" University speaker in it and powered it with a Heathkit amp. Had one of those AR 2 speed belt driven turntables with a fairly good cartridge in it and I was just styling man. The point being that I'm not entirely unfamiliar with this stuff but admittedly nowhere near the level of experience and knowledge as those of you on here.

I have the curse of being an anal perfectionist. I would very much like to avoid having that lovely trait get involved with this little project of mine or I'll end up like the worst (or best depending on your point of view) of you chasing after the most realistic sound I can get. I'll want to close my eyes and be there.

So in trying to keep this at a casual DIY dweeb (ignorance really is bliss) level I gather from what you guys have posted that a N1201-8A CO would be the choice for my collection of stuff, keeping in mind that the phasing will be off, it might screw up HF rolloff and God knows what else that eludes me, as opposed to the 501-8A I'm now using.

As one who is always looking for a free lunch all I want is for someone who knows more than I to tell me "keep your 501's or get a pair of XXXX's". Puhleeze do me this small favor before I pick up my lance and go looking for windmills. After having fallen down the rabbit hole.

Heh heh heh