"Crossover Design for New Project"

[Altec Best]

OK I think I could use some help on designing a Crossover from scratch that I need to complete project I would like to undertake.I have all the components and was talking with a friend "dgwojo" that I may need modeling software for the efficiency mismatches.Any and all suggestions or help would be most welcomed.OK the only components missing now are the Crossovers.I would like to use dual 416-8B's for LF and a 511E/288C with a 288-8G diaghram 23763 8 ohm for MF & HF and for UHF EV T350's all drivers are 8 ohm.

Now I talked to the Zilchster and he recommended that I use one of the woofers to 100 hz and below to augment the Bass as running both at full range they would conflict in the midrange.

Any Help would be most Appreciated Thank You in Advance to any assistance anyone could provide Thank You !

[Steve Mac]

I'm a big fan of active EQ...not passive so I'm not much help.
I am in somewhat a similar boat that I am beginning to put another system together
not too different than yours. Except I like simpler projects...yours is a beatiful but
could be a real gorilla in tweaking...but no doubt it might be worth it.

I'm thinking 511E but with GPA288H drivers...the high end is better methinks
so I do not need the ev tweeters...though gm may add that the ev tweeters bandwidth
may be more appropriate. Still I truly believe the fewer number of transducers...the better.
I'm thinking of the alnico gpa 416 speakers...I want brand new...that's just me.

But if I had 4-416's...then zilch's comments are spot on not just because that is exactly
what I would do. But it makes me think I could design a 3 way system with the behringer
and maybe have some passive xo across one of the 416Bs to keep the other one focused to
the midrange horn....now you got me thinking!

[Altec Best]

[quote=Steve Mac;1829458]

I am in somewhat a similar boat that I am beginning to put another system together
not too different than yours. Except I like simpler projects...yours is a beautiful but
could be a real gorilla in tweaking...but no doubt it might be worth it.

This is what I'm finding out and your right Steve I think it's worth it.

I'm thinking 511E but with GPA288H drivers...the high end is better methinks
so I do not need the ev tweeters...though gm may add that the ev tweeters bandwidth

may be more appropriate.

I have a couple different pairs of 288's ,I want to use these because the diaghrams are Brand New

Still I truly believe the fewer number of transducers...the better.
I'm thinking of the alnico gpa 416 speakers...I want brand new...that's just me.

1 pair of 416's are used but in great condition and the other pair I have are NOS still in the Altec Boxes.If I need to recone them (Used Ones) I will.

But if I had 4-416's...then zilch's comments are spot on not just because that is exactly
what I would do. But it makes me think I could design a 3 way system with the behringer
and maybe have some passive xo across one of the 416Bs to keep the other one focused to
the midrange horn....now you got me thinking

But I truly believe that 1 woofer cannot keep up with a 288 without having to shelve it completely it just overpowers and drowns out 1 LF transducer.In almost every Altec system that a large format driver is used 2 woofers are usually the norm.Let me know if you come up with anything !!

I'll send GM a email see if he can help Thank You Steve ! :2thumbsup:

[SOOTSHE]

I'm afraid I'm not going to be much help John.....It's going to take all my wits to come up with the new crossovers for my 19's even though I have the schematic!!! I'm a complete novice at this crossover stuff.

Having said that, I'll be following this closely though, as I think you are putting together a killer system here. What type of design are you going for with the bass bin?

I think the dual 416's will be awesome....are you thinking 500hz, 6K?

[Steve Mac]

But I truly believe that 1 woofer cannot keep up with a 288 without having to shelve it completely it just overpowers and drowns out 1 LF transducer.In almost every Altec system that a large format driver is used 2 woofers are usually the norm.Let me know if you come up with anything !!

I'll send GM a email see if he can help Thank You Steve ! :2thumbsup:

passive yes...active no...the secret of my success have been the attenuators I use on the output of the behringer XO...that way I pump up the juice to the crossover but limit signal to the power amps. One big benefit of active is I can try hundreds of slopes/gains, eq,safety limiting, etc with the behringer... in effect I don't want the amp/speaker/xo to be tied together...it's just too limiting. I'm seriously considering an SET amp for the smaller system on top and with bi/tri-amping it's so much easier to mix/match and experiment.

I believe in your case you are trying to build the rod speaker right? If that's the case you need to research what they used for that project and tweak away.

[Altec Best]

What type of design are you going for with the bass bin?

I think the dual 416's will be awesome....are you thinking 500hz, 6K?

I'm not sure yet on the bass bins I'm waiting to see what GM says about an over and under drivers with a sled on top for the horns.As far as the 511 horn I would like to see that go to at least 8k or 10k and then bring in the T350 around there.

I believe in your case you are trying to build the rod speaker right? If that's the case you need to research what they used for that project and tweak away.

Similar to the Rod I prefer the drivers over and under GM built one like that if you check out his album on his profile page he has a picture of one with a 511 on top.I'm thinking something like that except with a T350 as a super tweeter too I talked to him yesterday but he is alittle under the weather right now Hope he gets well soon :2thumbsup: Thanks Steve :thankU: John

[bfish]

I'd suggest measuring the T/S parameters on your 416s before settling on boxes for them. Any two in one box need to be verrry close ITR. Impedance plots and matching that as well. AFAIK, the current kits are the one-size-fits-all 416C kit Altec was using when they quit, so if you recone any, you'll probably need to do them all for the best matchup, and even I would wince doing that to NOS Bs.

Another option to use what you have if they don't match well enough is a 4-box MTM.

Doing a passive XO for a 3-way with mid and HF horns of such vastly different dimensions... I wouldn't go there. Go active 3-way and dial in the XO and delay. Be aware though that not all active XOs offer delay for the HF.

[GM]

I'm not sure yet on the bass bins I'm waiting to see what GM says about an over and under drivers with a sled on top for the horns.As far as the 511 horn I would like to see that go to at least 8k or 10k and then bring in the T350 around there.

I talked to him yesterday but he is alittle under the weather right now Hope he gets well soon

FWIW, I've periodically mentioned that my current speakers are anything but optimum. They are the original 'subs' used to fill in below chopped up 210s except with ~stock 511/808-8a loaded with Ultralights to effectively make them 802-8A. As such, they suck by my standards, sounding best from outside the room and even then, music scales obnoxiously 'walk' up-down between the horn/woofers and some musical instruments sound way too tall due to the acoustic centers being so far apart for a N501-8A.

WRT adding super tweeters, ideally you want to match the two horn's polar responses at least around the XO point, but I've never seen any published plots of older speaker components other than Altec's, so typically requires lots of trial n' error if no measurements are made.

Thanks, though for me, getting 'well' these days means not feeling as bad as the day before.

[GM]

... in effect I don't want the amp/speaker/xo to be tied together...it's just too limiting. I'm seriously considering an SET amp for the smaller system on top and with bi/tri-amping it's so much easier to mix/match and experiment.

Agreed, though I prefer lots of Class A or at least very low -fb SS power with passives to impedance match to compression horns to keep from clipping transients.

GM

[GM]

[quote=Altec Best;1829472]

But I truly believe that 1 woofer cannot keep up with a 288 without having to shelve it completely it just overpowers and drowns out 1 LF transducer.In almost every Altec system that a large format driver is used 2 woofers are usually the norm.Let me know if you come up with anything !!

That, or horn load a single to produce the output of two with the trade-off being a truly huge cab if loaded enough to match the dual woofers down low.

The question though is whether or not the 288 has enough dynamic headroom left once shelved to meet the needs of the app. For prosound it doesn't, but for HIFI/HT apps it should except for maybe the 'Headbanger's Ball' types.

GM