"Crossover Design for New Project"

**Panomaniac** · July 11th, 2010, 07:01 PM

Hey AB. I just got back from Ohio and the Midwest audiofest. I'm a bit toasted, but can be of more help tomorrow.

I'm sure we can figure out something.

**SOOTSHE** · July 12th, 2010, 04:30 AM

Originally Posted by bfish

You're welcome.

I've not used one, but this has all the bells and whistles;

BEHRINGER: DCX2496

Pretty popular among DIYers, just verify it'll do stereo 3-way.

Yes, it will certainly do stereo 3 way, but I've heard quite a few comments that the sound quality is not really up to scratch......the old digital/analog discussion.

What do you expect for $300?

A lot of users use these to find the correct parameters & then build their passives from those settings.

**Panomaniac** · July 12th, 2010, 10:49 AM

Yeah, the DCX is super handy for trying a lot of different things. I've done that a lot, then built passive.

I can certainly help here. I can send you my WT3 to do impedance sweeps, or you might want to pick one up. Getting good sweep measurements of each section would also be a big help. Do you have the hardware to do it?

I don't think I'd go below 700Hz 2nd order on the 511/288. Not sure for the top end.
And you'd probably want some underlap between the horn and bass section - 20~30%.
So first draft would be 600 LP + 800HP 2nd order. That's a starting point. Put an L-pad on the horn for level adjust. I would run the 15s in parallel if your amp can drive a 4 ohm load.

The 511 can be hot in the 500Hz-1K region, so that would need to be tamed via crossover or EQ.

What's your bass cab?

**Steve Mac** · July 12th, 2010, 10:54 AM

Originally Posted by J Henry

Yes, it will certainly do stereo 3 way, but I've heard quite a few comments that the sound quality is not really up to scratch......the old digital/analog discussion.

What do you expect for $300?

A lot of users use these to find the correct parameters & then build their passives from those settings.

Some folks don't feel comfortable unless they empty their wallets too.

I run digital into the unit...one D/A on the output and make sure I get a big signal into the crossover to get the resolution out of it. Most passives are effect processors(i.e. they have a sound of their own)... So, I think passives offer their own negatives as well. I just remember when my Dad played with his stereo back in the 60s that the crossovers stopped or limited tweaking all the time...and were more of a black art back when to those guys.

On top of all this are several tweaks that can be made to the dcx if you own one that will clean up the d/a and improve the clocking of the digital input. So rather than clean it up with passives....clean up the dcx and retain the high tweakibility factor. As they say though, YMMV....

**Altec Best** · July 12th, 2010, 06:40 PM

[quote=Panomaniac;1829564]

Yeah, the DCX is super handy for trying a lot of different things. I've done that a lot, then built passive.

Well I don't have one of those yet.

I can certainly help here. I can send you my WT3 to do impedance sweeps, or you might want to pick one up. Getting good sweep measurements of each section would also be a big help. Do you have the hardware to do it?

I'm working on it and Thanks for the offer Pano I'll call you !!!

I don't think I'd go below 700Hz 2nd order on the 511/288. Not sure for the top end.

I was thinking 800 to 1000hz to 8k to 10khz on the top and then bring in the super tweeter T350 for the UHF

So first draft would be 600 LP + 800HP 2nd order. That's a starting point. Put an L-pad on the horn for level adjust. I would run the 15s in parallel if your amp can drive a 4 ohm load.

All drivers are 8 ohm Unfortunately at the moment I'm stuck with 8 ohm loads and would like to have an L-pad to adjust the horn and then could be taken out later after dialed in.

What's your bass cab?

I'm still very early into this yet all drivers I needed I got now I was waiting for the EV T350's now they have arrived all I need is the XO's and cabinets.Which I have to build yet.I'm thinking a box with the rear corners tapered to push back into a corner with a over under 416 configuration.I haven't decided whether to separate them yet inside of box.It will look like one box from the outside but in reality it would be 2 stacked together.Zilch said they could interfere with each other in the midrange and he recommended to limit one of the woof's to 100hz and below.Basically to augment the other.I'm thinking I maybe able to get around that if they are separated.Any thoughts on this ? I would rather both woofer's running full range as I really feel the 288 needs it.But if i can't then I would have to follow his recommendation I guess,this is why I'm posting here for the guys with Altec experience as he said he was limited with Altec drivers he is familiar with JBL.

[quote=Steve Mac;1829566]

Some folks don't feel comfortable unless they empty their wallets too.

Well I've already done that acquiring the drivers and horns

Now I just have to shell out for the Crossovers and some Baltic Birch and fiberglass.

I run digital into the unit...one D/A on the output and make sure I get a big signal into the crossover to get the resolution out of it. Most passives are effect processors(i.e. they have a sound of their own)... So, I think passives offer their own negatives as well. I just remember when my Dad played with his stereo back in the 60s that the crossovers stopped or limited tweaking all the time...and were more of a black art back when to those guys.

Well I'm hoping I don't have to tweak till the cows come home.

I would like to get it close as possible the first time so the adjustments will be minor.As pano suggested I think a L-pad is almost mandatory when using a large format driver in a home setting.This is why I feel dual 416's are required to keep up with the 511/288's I have a 288/1005 right now on top of a 416B in a 612 cabinet and I can tell you I have to shelve the 288 all the way for them to sound good and they do.Extremely loud,same amount of power next to my 19's they are twice as loud as the 19's that tells me they are much more efficient than the 19's.Midrange is Awesome !!

On top of all this are several tweaks that can be made to the dcx if you own one that will clean up the d/a and improve the clocking of the digital input. So rather than clean it up with passives....clean up the dcx and retain the high tweakibility factor. As they say though, YMMV....[/

QUOTE]

This is quite interesting Steve and haven't thought about this option which does make a lot of sense.However I was hoping to just be able to build a set of passives without having to shell out more dough other than caps,resistors,coils,etc...

As this is my first complete speaker build from scratch I could have chosen something maybe easier less complicated,but as my space is quickly disappearing from the large quanities of loudspeakers to the ceiling

I thought I would try to build the Best one I could and be done with it and hang up my Saw.On second thought Nahh maybe Not

Well if I can complete this with the results I'm looking for I can start to thin the heard so to speak. :2thumbsup: Thank You everyone for your input and suggestions/help I appreciate as this is going to need the expertise of you gentleman.:thankU: Best Regards ~ John

**bfish** · July 12th, 2010, 07:31 PM

Lacking published FR and polar plots for 511E/288, assuming they're the same as a 511B/802 on the bottom end is... well... an assumption.

Same for selecting an XO point before deciding on LF cab(s). You're seeking a near polar match for the LF/MF at XO. With the LF narrowing as F rises and MF widening as F lowers, there's gonna be a sweet spot where they ~match*.

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

Brainfurt; was there one in the old tech letters?

*Same goes for the MF/HF XO.

**Panomaniac** · July 12th, 2010, 09:32 PM

I thought you said you will be running 2x 416s per side. So together a 4 ohm load, right?
Don't worry too much about the interference of the woofers if you keep them under 1K.
Not to say that crossing one lower is a bad thing, it can give you a flatter response because you have 2 instead of one down low.

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.

**westend9** · July 12th, 2010, 10:33 PM

Following along on this build since I'm attempting a lesser project, using only one 416-8b.
I've had really good luck with a Behringer CX-3400 crossover. My plans are to upgrade to the DCX 2496 when I am a little further along. I had been looking at how to get the same bass reinforcement as AB is trying to do, possibly using a different Altec woofer, ala 421 or similar. I am putting that on standby but I think two 416's would get a guy pretty well there in the bass dept.. Of course, some folks can never get enough bass.
Good luck with your project, AB!

**Steve Mac** · July 13th, 2010, 10:13 AM

Just a note....if you use one 416 for bass and one for mid bass/lower mid range...the efficiency gain is gone for the passive XO...right?

**Panomaniac** · July 13th, 2010, 10:48 AM

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.

Lunch is not free.....