Altec 803B Multicell Horn in home use??

Hello dear Altec-users,

this is my first here.
My name is Jonas and I'm from Germany, I'm 19 years old and I'm going to build up my own Voice Of The Theatre system pretty soon.
Because there was a chance to get the 803B Multicell horns I bought them and I also have Altec 288D drivers.
The other part of my A5 consists of original American 828B cabinets with a A416WVL woofer. This is a field coil speaker manufactured by the German Wolf von Langa.
My first crossover will by like the Hiraga A5 for the start and will maybe improved.

My taste of music is blues and psychedelic of the 60's and I hardly listen to anything else but records.

My question:
My room has sth about 23m?, sorry I will compare it to inch etc later.. :o
The listening distance is ca. 3 meters.
Will this work with the 803B horn? Or would a 805 or 1005 horn do a better job on that?


Best of luck,
Jonas

Welcome to the forum - and congratulations on your rig. You're starting out right!

I am listening to the 803B horns right now at about 3m distance and they are fine. The 803 is a very directional horn, very tight - so it does not splash off the wall much. The 1505 that Hiraga uses is much wider - and I think a bit flatter at the top end. The 803B will play lower, but drops off at the top end. so the crossover for the 1505 is not ideal for the 803, although it is a good place to start.

Anyhow, the 803 is a great start and is often much cheaper than the 1005 or the 1505.

just FYI - I'm the guy who helped Mr. Hiraga rebuild those A5s. See my avatar. Of course that was a few years before you were born! =)

Welcome Jonas there are alot of knowledgeable guys here that will help you at the Altec site.Your starting off with a very nice project good luck with it and have fun. :)

Hello,

thank you for your answers.
Do you may have a solution for the crossover?
I heared somewhere that there is the possibility to raise the treble of the speaker.
Or should I better look for a tweeter?
Which tweeter is recommended for Altec use?

Hi Jonas,
Hiraga used JBL tweeters. The bullet or the slot type. Seemed to work well.
With the 300Hz horn you won't get a lot of high end, that's why the 500Hz horns are more popular. The 1005 seems the most popular for home use.
The published Hiraga A5 crossover has a high freq. boost for the horn.

Nothing wrong with adding a tweeter. Look for the JBL 2402, 2404 or 2405.
I'm sure the guys here can give Altec suggestions.

Quote:

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Originally Posted by Panomaniac

With the 300Hz horn you won't get a lot of high end, that's why the 500Hz horns are more popular

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What does that mean?
Does it mean it doesn't sound good or it is not popular in home use?

The 300Hz horns do not have as much treble as the 500Hz horns. Mostly because they are longer hrons. So you need to use a lower crossover point with your tweeter to get enough treble. On the 500Hz horns you can almost get away with no tweeter. I often did for live gigs.

The 300Hz horns sound great, no problem. But as you have found, they are BIG. (Imagine the 1803) So they are not as popular for home use. I think that the 1005 is very sought after because it is a "good size" for home use. Not too giant, but big enough to sound great.

The 803B is a great place to start - I love mine. But you WILL need a tweeter, that's all.
You should measure your 288/803 to see at what frequency you need to bring in the tweeter. It should be somewhere in the region of 5K-8K.

So I say start with the 803. Keep your eyes open for a good deal on a 1005, or even the 1505, if you have room for it. Who knows, you may be so happy with the 803 that you will forget any other horn. :D

Once I get a pair of throats from ePay last week I may try 803B horns suspended pointing downward at an angle a foot or so from the ceiling. The 825/515's will be directly below them on the floor. My reason for this is the 803's are deeper than the cabs and if voice coils are to be aligned the horn would stick out over the front of the bass horn. I could also use the real estate atop the 825's for other things.
Anyone else tried horns hung rather than the usual way?
Jon A.

I think I need your help for the crossover.

I Have 16 Ohms 288 driver and 8 Ohms woofer.
I could buy a JBL 2405 with 16 Ohms.

But which crossover layout sounds nice?
Does anybody have experience on that issue?

Quote:

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Originally Posted by aeyb701

I may try 803B horns suspended pointing downward at an angle a foot or so from the ceiling. .

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Funny - I've been thinking of the same thing. Would sure be nice. And I want to do them on pulleys (12' ceiling) so that I can hoist them out of the way.
Only trouble is - where to put them? I have not found the ideal spot for the bass cabs yet.


Jonas. Use the 16 ohm section of the published crossover for your 288s, and the 8 ohm section for your woofers.
You can buy any of the JBL tweeters you want. 16 ohm might me a littler easier, that's all. But the tweeter crossover can be calculated for 8 or 16. It could be as simple as 1 cap and 1 resistor.

Just know that as Jon notes above, the 803 horns are long, so to get them lined up right with your woofers the front of the horn will stick out beyond the front of the cab. There are crossover tricks to get around this, more on that later.

Quote:

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Originally Posted by Panomaniac

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

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Ok, I will wait for that.. ;) ;)

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.

Quote:

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Originally Posted by bfish

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.

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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

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.

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. :rolleyes:

I will also add some pictures of my system later.

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

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.

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.

Quote:

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Originally Posted by Jonas@Psychedelic

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

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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:

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.

Quote:

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Originally Posted by Jonas@Psychedelic

Could someone help me please?

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To each his own - on cabs,bracing cabs !

WRT crossovers, not my strong suit, would help out if I could. Pano is over at DIY audio forum, more than here, if no one can help here, i would go there and ask him.Since he was already here in your thread.And he has a pair that he just did of the 828's. Search this forum "A-5 Journey" and it should come up.

diyAudio

I just read many threads about bracing the horn flares and the wole cabinet. That was very interesting and I learned much. I have braced my flares like it's done in the 825 cabinet plan. I will try to use self-adhesive bitumen to dampen the flares and I also want to try to dampen the wole cabinet's side walls with that method. Are there some pictures of a well-braced cabinet (not flares)?
Thanks a lot so far.

Pictures here of cabinet build:825/828

To experiment with your crossover and an additional tweeter, could you add into the HF section an L-pad and a film cap? Depending on efficiency matches, you may even be able to forgo the L-pad.
Here is a handy little crossover calculator.