6 dB per Octave Passive Crossovers

[Alien_Shore]

I think what OG may have been hitting at is that with a good active XO setup, you should be able to make the necessary adjustments for time delays, room acoustics, etc. As far as hearing differences with bi-amping, that would explain why you want to go with the simplest passive XO possible, since passive filters can actually introduce more issues.

I wouldn't say that I'm an advocate for 1st order XO, but I've been doing a lot of simulating, prototypes, and measurements with different filters recently. My "test bed" is a 416A in an 816 cabinet, along with 802-8G HF mounted to a 511B horn. My findings thus far is that it is hard to beat the 12dB Altec network, which includes dual HF/MF shelving controls and impedance eq on the woofer. Originally I was trying to simplify and dial in the XO to the specific drivers mentioned. I tried to lower the XO point from 1200 down a bit lower and see if the HF horns would sound richer and also see if I could improve the LF response a little bit by not having the woofer reach quite so high. I've tried 1st order HP and LP filters, 2nd order, and even 3rd order. I have also played with simple HF attenuation, and customizing the Altec dual shelving circuits. I'm zeroing in on some pretty good results, but it certainly is not leaning towards 1st order at this point.

[Old Guy]

Jeff, I simply don't care what you can sense. A GOOD active setup allows adjustments for many things. There are DOZENS of active crossovers. You tried one setup, and are now spreading the word that ALL active setups are bad. You are not qualified to say that.

Part of this is the language barrier. the words you choose come across very strong in English. I have been doing audio probably twice as long as you have been alive. I no longer have time for you or your attitude.Sorry.

Bottom line, a whole lot of equipment you have never seen. Don't judge it all before you see it.

[SD-50]

Also benefit from a 6db xo on my A7s. The original Altec xo's were missing when I bought the used A7s; the 12db after-market replacements were dreadful. At any rate, following countless hours of trail and error settled on the 6db xo, at approximately 600hz as the most musical, transparent, and dynamic XO I could cobble together without any sort of test gear, other than my ears. Power handling is not an issue as I rarely listen above loud conversation level.
No doubt, there are issues with the xo that need to be rectify, but without proper test gear and a lack of technical skills, it?s just not going to happen.
I?ll post a drawing of the xo later, welcome all comments, useful or otherwise.
Cheers

[rontec]

Also benefit from a 6db xo on my A7s. The original Altec xo's were missing when I bought the used A7s; the 12db after-market replacements were dreadful. At any rate, following countless hours of trail and error settled on the 6db xo, at approximately 600hz as the most musical, transparent, and dynamic XO I could cobble together without any sort of test gear, other than my ears. Power handling is not an issue as I rarely listen above loud conversation level.
No doubt, there are issues with the xo that need to be rectify, but without proper test gear and a lack of technical skills, it?s just not going to happen.
I?ll post a drawing of the xo later, welcome all comments, useful or otherwise.
Cheers

My experience and conclusion as well. I was going to say in my earlier post that the 6db xo worked well at medium to moderately loud volume only. Couldn't keep up with my 19's at high volume! Would like to see your xo drawing and values.

[RonSSS]

I never cared for biamping my M19's either. And I used identical amps for highs and lows. PP 6B4G modified Heath W5's. No sand amps in my system. The issue was probably my x-overs, but just never messed with the whole thing because the stock x-over just sounded better.
I have messed with 6db slope stuff. On A7's as well. But the woofer section has a peak at 250-300hz, and that just became accentuated. To my ears anyway.
So Jeff, do it and have fun and tell us what you hear.
Ron

[mah]

OG, LowOhms asked "Can I gain from your expert arcane experiences".

arcane definition: arcane - Wiktionary

Is this a speciality of yours?

[badtoby]

Can't we all just ..... Get along? And have a good time.

[zelgall]

Jeff, there is another Jeff from your neck of the woods that posts on another forum. He has some experience with both 2A3's and Altec speakers and may be able to give you a demo or at least some local perspective on your quest.

[LowOhms]

Jeff, I simply don't care what you can sense. A GOOD active setup allows adjustments for many things. There are DOZENS of active crossovers. You tried one setup, and are now spreading the word that ALL active setups are bad. You are not qualified to say that.

Part of this is the language barrier. the words you choose come across very strong in English. I have been doing audio probably twice as long as you have been alive. I no longer have time for you or your attitude.Sorry.

Bottom line, a whole lot of equipment you have never seen. Don't judge it all before you see it.

Hi OG,

You assumed things you shouldn't.

You state " I have been doing audio probably twice as long as you have been alive."

Really, I am 68 years of age. OG, have you been doing audio for 136 years ??

I was about eight years old ( guessing ) when my Dad sneaked the ALTEC 604B duplex into our home, while Mom was sleeping.

Do you have ANY idea what my background is in audio? No, you don't, not at all.

Did me mentioning using pairs of RCA Ubangies and MI-1428B field coil large format drivers in my living room register ....... mentally with you ?

Why not just leave this alone between the two of us. Peace. Heck, it is possible I may be older than you and / or more experienced with high end audio than you. It really doesn't matter at all. What matters is this : we both derive fun from our respective audio hobbies !! Also, we should be respectful to each other.

Now, in January 2013, I am simply interested in exploring 6 dB passive crossovers topics with those Altec A7 users that are either doing it, or have done it and those who tried it and discarded it !!

You are right about communicating on line. It leaves a LOT to be desired compared, say, to even a simple telephone call. Better yet, I wish I could meet you, break bread together ( except I am a vegetarian and I don't eat bread ) ...we would probably have a lot of fun together. Hey, attend RMAF 2014 in Denver, we will meet, I'll be there, running GPA 15s in a nice MLTL, for my best friends. Single amped,....one 2A3.

Cheers,

Jeff

[just me now]

is RMAF a great show? I should take off and attend some year...