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?

[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

[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

[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!

[Bob Womack]

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

Thanks! This room was built according to Live-End Dead-End principles, one of which is to prevent conduction through walls and floor to the mix position. As you may know, conduction through a solid transfers sound faster than through a gas, so when the sound is re-radiated from the floor to the mix position, phase interference results.

To prevent this, we cut through the concrete building foundation and poured new footings into the ground underneath the floor with bolts integrated to secure steel columns. The columns were fabricated with flanges at each end to bolt to the footings and accept the receiving boxes on top. The receiving boxes were fabricated from double layer, glued and screwed, 3/4" plywood. Once they were fabricated, mounted, and aligned, conduit was run to them and wall construction could begin. The triple walls were erected separately with no physical connection between themselves and the boxes and mounts. You can see a bit of the white flexible sealant used to fill the gap between the boxes and the wall at the bottom of the opening.

Once the room was in the final construction stages, the wiring was run and the boxes were lined with dense rubber strips to isolate the speakers. The speakers were then press-fit into the boxes. As an LEDE roon (unlicensed in this case), the control room is largely anechoic on the front and and diffuse on the rear. There are RPG quadratic diffusers across the rear that were designed specifically for our installation by Peter D’Antonio at RPG Systems.

I have lots of questions (sorry)

No problem!

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

I really don't know the wiring config for the "B" version of this speaker but the "C" variant has the option to power the LF separately. It should be noted that the manual for the "C" version specifically warns against electronically pushing the response below 80hz more than 6db to extend the frequency response. The stated reason is to prevent distortion and damage. It recommends that no boost at all be applied below 30hz for the same reasons. That's one reason why I've approached the LF situation at home from the angle of using an external subwoofer. I'm not sure that bi-amping the systems and pushing the response in the LF range won't just cause the same effects.

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

Addressed by another poster.

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

For home use, probably. For a control room, the manual suggests a minimum of 300 watts at 4 ohms, to allow more dynamic range without distortion. Remember that if you subwoof your system with separate amplification, you are reducing the wattage requirements for the main system.

By the way, while we were building the room, we operated these 813B/Cs unsoffitted in another room and they worked fine. The soffitting extended the bass response, but I'll be honest that I aesthetically prefer the LF range of my subwoofed 811Cs at home. I've described it this way on the forum before: The soffitted 813s have a smoother bass response than the non-soffitted, subwoofed 811s, but the subwoofed 811s have a more solid, deeper low-end.

It should be noted that the 813s are powered by David Hafler amps and gently smoothed by Clarke-Technik room EQs. Because they are used as primary control monitors, the installation has been TEF'd for frequency response and time spectrum analysis. The mixes I create on these monitors are very predictable and balanced.

The 811s came out of a control room and are now my home system. Though I've done rudimentary frequency sweeps, I can't vouched for their accuracy and no mixing is being done on them. I do audition work at home, but that's about it. They are set to be pleasing, not dead accurate.

Bob

[Urei809]

This post will not be helpful at all, I assure you, but I just wanted to say I have ALWAYS wanted a pair of 813's. Currently I have 809's that I have had reconed (10+ years ago) by the only person in Michigan certified to work on Ureis and recently rebuilt the cabinets to make them more appealing in the livingroom.

The cabinets are identical in construction to the original cabinets with the exception that I have created a lip that will hold a speaker grill.


Anyway, I am extremely jealous.

[Charles0322]

Thanks! This room was built according to Live-End Dead-End principles, one of which is to prevent conduction through walls and floor to the mix position. As you may know, conduction through a solid transfers sound faster than through a gas, so when the sound is re-radiated from the floor to the mix position, phase interference results.
Bob

The level of specifications awes me I admire people who take sound to the next level!

I will build these 2226 bass cabs, two of them, use them in stereo as Mr. Hoda suggests. Can I use the 8ohm version to the same effect as the suggested 4 ohm?

Soffits is way to involved for my budget and I just don't have that specifically designed room to suit.

I want to thank everyone contributing to this thread!

[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

[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!

[mikeharris]

i have a set of new old stock 813 crossovers we discover while cleaning up

[UreiCollector]

Have you made any progress with the 813's?