Altec 803B Multicell Horn in home use??

[Jonas@Psychedelic]

There are crossover tricks to get around this, more on that later.

Ok, I will wait for that..

[bfish]

Using active XO with the appropriate LF delay would be preferrable to separating the components further than they already are. Even with a stock A7 you have to be ~30 feet away before you can no longer tell the two sources are at different locations. Add several feet to that separation by hanging the HF, and you'd need to be... well... a long ways away for it to sound like a single source.

While many active XOs offer adjustable delay, not that many offer it on the LF band, which is needed when the HF driver is "behind" the LF.

[GM]

While many active XOs offer adjustable delay, not that many offer it on the LF band, which is needed when the HF driver is "behind" the LF.

Depends on how far back it is since the XO's phase delay (which moves the HF's acoustic center behind the LF's, increasing with increasing slope order) may require it be set back even further in the case of an 825 or similar horn cab.

GM

[Panomaniac]

Well the Behringer DCX2496 let's you do all that and more, but is not the greatest sounding piece of gear. At least not in stock form. But that's for a whole other forum!

A nice passive can be done. But it does need to take all these things into account.

[Jonas@Psychedelic]

Hello again,
some time has passed and I've got to know my speakers much better now.
I also build two 825 cabinets myself and use them now instead of the originals, but I'm still not sure on the damping material, since fiberglass isn't the material of choice for the domestic use, I think.

I still have the 803 Horns, because in Germany it's hard to find any 500cycle horn and shipping a 1005 from the States to Germany is obviously a difficult topic.

I also have an A7 lineup with 802-8G drivers and a 511B horn, that sounds very nice at the top end with very detailed sound and much more focus than the A5 with the Hiraga crossover. But the A7 lacks the natural sound of the A5 and the relaxed feeling that a multicell horn gives you.

BUT I still don't have a super tweeter and I think now it's time to change that, you already recommended the JBL alnico tweeters and I have a friend who uses a radial tweeter with a 1505+288-16G + 515B with an active crossover. That sounds nice.
But what is the price range for an original tweeter?

And how do I connect it to my Hiraga crossover?
Could somebody help me? Because I lack knowledge about crossover techniques, I just can read plans and solder.

I will also add some pictures of my system later.

[GM]

There's nothing wrong with using fiberglass as long as you use a vent screen to keep any dust from exiting the cab. Regardless, you should cover the vent anyway using however much density is required to critically damp it when tightly stretched across it, i.e. remove any hollow box sound and echoes from the back side of the driver that the wall damping may not have attenuated enough.

FWIW, I had the same issues WRT small Vs large format horns and found that two 511/802 combos stacked on top of each other yielded the 'full' mids of the larger with the 'sweet' HF of the smaller plus a bit better overall polar response.

GM

[Jonas@Psychedelic]

I will try to cover the vent, never thought that this could make a difference in sound, I'll try, thank you for your input.
I'm also interested in bracing the cabinet, since I have built my cabinet from 15mm birch plywood according to the original plans. I'll read on that issue in this forum, nice to see that there have been so many discussions about that.

[Jonas@Psychedelic]

Does anybody know the Hiraga crossover for the 3-way-system? He recommends a tweeter, I think, but I just know his 2 way 8 and 16 ohm schematic, that I use myself.

[Altec Best]

I have built my cabinet from 15mm birch plywood according to the original plans.

Since you built yourself, you should have really used 19mm or 3/4 ply Minimum.As you can control every aspect of your build, a solid thick (Void Free) ply is preferable. 15 mm is only what 9/16" or 5/8" correct.They are too flimsy IMO, no matter how much you brace it, they will still resonate much more than a thicker ply.

But anyway diagonal bracing should be employed on all sides IMHO.Good Luck, and we all Love to see Pictures Here of peoples Altec projects (Builds) ! :2thumbsup:

[Jonas@Psychedelic]

Since I'm interested in Altec I found out that there are two philosophies: The people who say bracing is important and the cabinet should sound "dead" and the people who say that the resonances are part of the speaker's conmstruction. The original 825 cabinets also had the thinner material, so I built up these. Of course I still have the chance to add another line of plywood to the ooutside walls.
But I'll do it step by step, since I'm just at the beginning of my journey. ;-)

I have the A5 for 1 1/3 years now. In the beginning they sounded pretty terrible, there were several room problems and I had to get to know the speaker, but now I'm at a point where it sounds pretty good. At this stage I really want to try something, that's why I'd like to know how to include a tweeter to my Hiraga 2 way crossover. Could someone help me please?

After trying that I want to do some "modifications" to the cabinet...

I found a picture of the speakers. Today they are placed slightly different and are more pointing to the listening place.