"Crossover Design for New Project"

[Altec Best]

(Besides, we all wanna see some 511E/288 plots)...:coffeedrinker:

.

Me too I'm really looking forward to it.As regards to the LF cab I was kinda waiting for GM to give me some advice on cabinet. But he is alittle under the weather at the moment.I hope he is OK.

]I thought you said you will be running 2x 416s per side. So together a 4 ohm load, right?

I am, 2 416-8B's perside.If I hook them up in parallel it will be 4 ohm in series 16 ohm so how do I keep this all 8 ohm.

Measure, measure, measure. You do need to measure.
I guess I could lend you some gear, if you don't want to invest in your own

.[/QUOTE]

Or you can send me a shopping list, Another shopping list just what I need. I think you did tell me on the phone awhile back but can't seem to find what i did with that paper.Thanks Mike !!!

Of course, some folks can never get enough bass.
Good luck with your project, AB!

I'm one of them helps get my feet moving if you know what I mean.I love good clean distortion free bass.Thank You Kindly for the well wishes.After I get the help I need to get this going I will document for everyones reference.If it can help others in the future then that is a good thing !Thanks again

[quote=Panomaniac;1829667]

Yes and no, depends on how you look at it. If you want more bass extension, the 1.5 setup will do that. If you wanted the same flat response out of 2 woofers running the full bass spectrum, you'd have to attenuate the upper range anyway. So there goes the sensitivity.

The only way to keep the sensitivity up is to give up on the low end. That may be a reasonable trade off. All depends on what you want.

Well I like all Bass, Mid-Range,and top end or HF/UHF But as these speakers are super efficient anyway wouldn't that still leave them pretty efficient with a flat response across the board ??? I will follow your recommendations as you guys are much more versed in XO's than I.

[bfish]

(Besides, we all wanna see some 511E/288 plots)...:coffeedrinker:

Brainfurt; was there one in the old tech letters?

Well it wasn't in the tech letters, it was in the old 9848 brochure. (courtesy Lansing Heritage)

(Added; the tech letters did give the 288/511 sensitivity rating, 105dB)

Yeah, 9848s used 411s, but the directivity of two vertical 15s should be a reliable constant, and you also have the directivity data from 700Hz-8K for the 288/511E.

All well and good, but it does raise the question, 'why didn't they do it with two 416s'...?

GM demo'd some 9848s I believe, I'm sure he'll have some positive input.

(Feel better soon GM).

[Panomaniac]

Don't worry about the 4 ohm thing, in fact it's good if you're driving it with solid state.
The crossover will be done on the real impedance of the drivers, not just a nominal 4 or 8 ohms. And a 4 ohm load saves you money on inductors.

How much room do you have for the bass bins? You know I'm thinking Onken W. That would be killer, but takes up a lot of room. Where you going to do the side by side thing, or one up above the other?

Thanks to bfish for the link, it's a help. Crossover was 700Hz, that's good news and easy to do.

Sure, I can send a shopping list of measurement gear. You ready to take the plunge?

[bfish]

Horizontal woofs would "flip" the directivity, necesitating a different XO point (among other things), one that would defeat much of the reason for using a 288.

[Panomaniac]

Why, wouldn't the horizontal woofers have a wider, shorter pattern? What was the monitor with 2 12s and the 811 horn?

Bottom line, what's the polar pattern of 2x15 and the 511 in the octave around 700Hz?

[bfish]

I guess I saw that coming, I was typing the following when you posted;

More on that...

A single woof radiates a fairly uniform, round pattern, which narrows with increasing frequency. However, when you put two in close proximity, the pattern becomes an ellipse, or for interpretive purposes, rectangular. The pattern is just the opposite of what your intuition would suggest though, with woofs stacked vertically, the pattern is wider horizontally, and vice versa.

This is borne out in the 9848 directivity plot I linked to. At 500Hz, the pattern is 135 degrees horizontal, and 60 degrees vertical. By the 700Hz XO point, the horizontal has narrowed to 90 degrees, and begins to blend with the 511 horizontal pattern.

So, if you flipped the woofs to side-by-side, the pattern flips too. You can see by the directivity plot how that won't meet the 511 polars at a reasonable frequency, with the woofs doing

xxx
xxx
xxx

and the horn doing

xxxxxxx
xxxxxxx

Yeah, Altec did side-by-sides too, but with a specific application in mind for which it worked. They also incorporated some directivity "steering" (via phase offset) into the design as well.

[Altec Best]

[/quote]bfish;1829687]

All well and good, but it does raise the question, 'why didn't they do it with two 416s'...?
GM demo'd some 9848s I believe, I'm sure he'll have some positive input.

(Feel better soon GM).

I believe the answer is that 411's use a sealed enclosure and require slightly less volume than 416's in a vented box therefore Altec could keep enclosure smaller even at it's current size (9848) it is still 200 Lbs. 49" high 34" wide and 23 1/4" deep
I hope he feels better too! He said he had a chance to check out the thread.Hopefully he will be able to post soon on a cabinet design for the 2 416's, he has a nice picture of a dual woof cabinet with a 511 on top of it on his profile page.That is similar to what I would like to do except mine will have a T350 on top of the 511E.And I think his woof's are 515's.


quote]=Panomaniac;1829688]

Don't worry about the 4 ohm thing, in fact it's good if you're driving i.t with solid state.

Yes I am at the moment running Solid State I needed more power.

The crossover will be done on the real impedance of the drivers, not just a nominal 4 or 8 ohms. And a 4 ohm load saves you money on inductors

That works any savings will be great.

How much room do you have for the bass bins? You know I'm thinking Onken W. That would be killer, but takes up a lot of room. Where you going to do the side by side thing, or one up above the other?

The Onken W won't work as they are going in the corner they can be as tall as the ceiling But space is limited so I would rather go up instead of across smaller footprint.So as Brad said one above the other is the right choice for me.

Thanks to bfish for the link, it's a help. Crossover was 700Hz, that's good news and easy to do.

I second that. Thank You Brad!!!

Sure, I can send a shopping list of measurement gear. You ready to take the plunge

Soon I'm thinking around the first, second week of August. I have a couple jobs to undertake first.Have to pay the bills first.After that I think I may take a few days off between jobs to get started.My lumber yard can have the Baltic in 1-2 days so that leaves the XO and again I'm just waiting for GM's recommendation on cab design.I'm just going to build a sled for the 511E/288 with the T350 on top of that.It will make it a whole lot easier moving it around as well.

I want to Thank, You Mike and Brad, for your assistance on a proper course of action. :thankU:

[Panomaniac]

Cool, vertical it is!

I'm about to hit the road for Pigeon Forge and Dollywood. Got to pick up a pair of 1005 horns. Yahoo! Talk to y'all later.

[Altec Best]

Let me know when you get back Pano.You can send that list anytime, I need to see how much these things will cost.May have to look for some bargains Save the money for the parts,wood,etc...

[edharbur]

Heres an offer. Bring your Baltic birch and a cutting list up to Ridgefield Ct, and I'll cut all the pieces for you. Takes about a minute a piece and they will be perfectly square and true. It will cost you a 6 pack of good beer. The offer stands for all of you local guys.

Ed