Urei 813b project

[Charles0322]

I'm looking for some creative input on options for a pr. of Urei 813b..

I have purchased 2226H for the lower end.. they were fitted with 2235H when bought and the 2425H / 801B combo for the hi/mids.

Should I bi-amp, tri-amp and breakaway from the time align x-over.. or is that what makes them special?

I am being told that to truly get the best out of them they need to be soffit mounted.

Thanks

[pos]

Hello Charles0322, welcome on this forum!

The 2226 will not give you near the same bass response as the 2235.
Even the 801B will likely go lower.
If you still have the 2235s you could try to get them reconed (assuming they need to).

EDIT: I think you're supposed to have 2234s as helper woofers there. That is the same basket as the 2235, even the same recone kit, the only difference being that the mass ring from the 2235 kit is not installed. So maybe you're best bet would be to sell your 2226s and get your 2235s reconed as 2234s ?

[Charles0322]

Hello Charles0322, welcome on this forum!

The 2226 will not give you near the same bass response as the 2235.
Even the 801B will likely go lower.
If you still have the 2235s you could try to get them reconed (assuming they need to).

EDIT: I think you're supposed to have 2234s as helper woofers there. That is the same basket as the 2235, even the same recone kit, the only difference being that the mass ring from the 2235 kit is not installed. So maybe you're best bet would be to sell your 2226s and get your 2235s reconed as 2234s ?

I was told to swap out the 2235 (as they needed reconing) for 2226 and bi-amp them with a bss x-over. I won't be needing the model 840 x-over? Does this make any sense?

Thank you very much for your input. A 2234 is different in which way from the 2235? How much are the 2226H worth second hand in good condition?

[Bob Womack]

I'm typing in front of these 813B/Cs right now:

They live in the soffit of a Live-End Dead-End control room with a grille over them.

The lovely phase coherence and lack of ear fatigue that are the greatest features of the 813s come from the crossover. These days, some are re-capping the crossovers to restore the specs.

The UREIs are, in fact, designed to be soffit-mounted and suffer from bass rolloff if they aren't. However, acoustic consultant Bob Hodas has written an excellent article about using subwoofers to counteract this very situation and has had good results. You can find the article HERE . Notice that he disagrees with the notion that bass is non-directional and suggests using stereo subwoofers.

Before I read his article, I happen to have stumbled upon a pair of the 813s smaller bothers, the 811cs, and set them up with a subwoofer on one side. Lo and behold, I was troubled to discover that I could discern that the low bass was arriving from one side. Right about that time I came across his article and set up my 811cs with dual subwoofers and was much happier.

Bob

[hjames]

I was told to swap out the 2235 (as they needed reconing) for 2226 and bi-amp them with a bss x-over. I won't be needing the model 840 x-over? Does this make any sense?

Thank you very much for your input. A 2234 is different in which way from the 2235? How much are the 2226H worth second hand in good condition?

2234 does not have the "massring" under the dustcap, but is otherwise the same as a 2235.

Read text and see picture -
http://audioheritage.org/vbulletin/showthread.php?t=919

[Charles0322]

I'm typing in front of these 813B/Cs right now:

They live in the soffit of a Live-End Dead-End control room with a grille over them.

The lovely phase coherence and lack of ear fatigue that are the greatest features of the 813s come from the crossover. These days, some are re-capping the crossovers to restore the specs.

Bob

Really nice soffit install. 3/4 ply press fit. What do you use for a base, sand or concrete?

I have lots of questions (sorry)

Do you think I can use the 2226H as subs? And re-cone the 2235 as a 2234?

how much should it cost to recap the the x-overs..

Right now I have two Crown PS-200's I'm using bridged mono.. is it sufficient for these in quality & power.

I respect this forum a great deal.. very nice to see people passionate about sound!

[Skywave-Rider]

I happen to have stumbled upon a pair of the 813s smaller bothers, the 811cs

Hey Bob, let me know if u want to get rid of them, LOL.

I miss using the 813s. They're less and less common. But great, as u know. Charles, best wishes on this project. I don't have much to offer but following with interest.

[Zilch]

Don't know about "B," but 813C would be biampable with crossover mods.

http://www.jblproservice.com/pdf/URE...s/813C-L,R.pdf

I believe you're getting bad advice elsewhere on several scores:

1) You're going to throw out the built-in passive time alignment and HF compensation, the system's major features, in favor of what?

2) 2226 is not a rational substitute for 2234/5; a comprehensive system redesign is implicit in doing that.

3) Does BSS provide the requisite tunings for 813B? In what bi/triamp configuration?

Suggest that your advisor(s) come here and discuss their proposals before you implement any of them.

Yes, you can make subs out of 2226s, but that's not merely a matter of sticking them in a box. They require active EQ in specific alignments to perform as subs....

[rs237]

and the 813C use the 2215H helper Woofer , or is this wrong ??

regards

juergen

[Zilch]

and the 813C use the 2215H helper Woofer , or is this wrong ??

3.5 mH/20 uF is not what I'd call a subwoofing lowpass.

The tapped inductor values for the coaxial woofer are not given, though I believe I was able to track those down at one time.

I'm not sure whether 2234H or 2235H would be the more appropriate substitute for 2215H in that system, either.... :dont-know

[Charles0322]

Don't know about "B," but 813C would be biampable with crossover mods.

http://www.jblproservice.com/pdf/URE...s/813C-L,R.pdf

I believe you're getting bad advice elsewhere on several scores:

1) You're going to throw out the built-in passive time alignment and HF compensation, the system's major features, in favor of what?

2) 2226 is not a rational substitute for 2234/5; a comprehensive system redesign is implicit in doing that.

3) Does BSS provide the requisite tunings for 813B? In what bi/triamp configuration?

Suggest that your advisor(s) come here and discuss their proposals before you implement any of them.

Yes, you can make subs out of 2226s, but that's not merely a matter of sticking them in a box. They require active EQ in specific alignments to perform as subs....

Thanks.. I'll make subs out of the 2226's and keep the Urei in stk form. Just recone the 2235s. Now to save up for Brystons!

[doodlebug]

Here's what I did with my 813A's. Just a standard crossover recap in both the front and rear units. Cost was somewhere on the order of $50 or so, IIRC. In my case, I had the Altec 604s reconed by GPA, too. They sing quite nicely now and I've used them for mixdown on a number of local band projects as well as daily listening. They're in storage for now until the new house is finished in March.

Most band members I've worked with these days haven't seen anything like the old-school monitors - until they hear themselves. About all they know are the near-field stuff at Guitar Center.

I appreciate the discussion here on the subwoof options. The 801s in my set are all original except for replaced foam surrounds at one or more points in their past. Mine aren't soffit mounted, either, and will likely never be due to living room limitations. I don't feel any problems with bass, though.

Cheers,

David

[Zilch]

Thanks.. I'll make subs out of the 2226's and keep the Urei in stk form. Just recone the 2235s. Now to save up for Brystons!

http://memweb.newsguy.com/~stigerik/almighty/index.html

[Robh3606]

The 813 A,B,C all use different drivers and crossovers. They are not interchangeable. If you have "B" there shouldn't be any JBL helper woofers in them. In the BX they had 2234's. The Le-15 and 2234 are almost equivalents as far as there LF extension.

Take a look here.

http://www.jblproservice.com/pdf/Sys...I%20Series.pdf

You can get the schematics here for the "C"s:

http://www.jblproservice.com/navigat...%20Series.html

And the "A+B"s here in the last pages of the manuals:

http://www.jblproservice.com/navigat...ectronics.html

The Tapped Inductors for any of the "C" series all have to be custom wound if you can get the winding information from JBL Pro.

Rob

[doodlebug]

http://memweb.newsguy.com/~stigerik/almighty/index.html

Ah, our man of a 1000 links.....Zilch, I always appreciate the quality and relevance of the things shared.

Cheers,

David