DIY "4345" Project

[pos]

The room is probably the problem with any response in the upper end. You can cross the eighteen and the ten lower. It isn't written in stone that you have to cross over at 290Hz or 340Hz. Anything that works in the 200 to 400 Hz range in your room will do.

That is quite interesting because this region (200-400) is right where the Schroeder frequency is in most roms. That is the frequency under wich modes become really sparse and individually noticeable and where Earl Geddes or Todd Welti suggest to use multiple sources to simulate those lost modes (ie multiple subs).

And whereas multiple subs are an ideal solution under 100Hz (because localisation), the upper region up to the Schroeder freqeuncy (100-200 or 100-300, depending on the size of the room) remains a problem in most cases.

Wayne Parham (PiSpeakers) suggest to use multiple sources for this range, but closer to the main speaker to avoid localisation problems.
This is what the E2 or 4435 do: two woofers playing the lowest octaves together, enlarging the radiation surface and exiting different modes of the room.

Well, that could also be done with the 4345 (if sufficiently raised from the ground to avoid problems with the 2245 in its upper range).
The 2245 and the 2122 can play together down to maybe 100Hz (and multiple subs would be used under that).

Here is a small picture explaning the proposed crossover (these are acoustic slopes, not just electrical ones).
This is something I plan to try with my 2245H/2020H, with a digital crossover.

[phamphare]

Absolutely fantastic !
Never seen such a perfect work.

And thank you for the documentation because I am beginning to follow the same lane.
For the time I collect spare parts.

I came to, precisely, this model 4345 because I had, long years ago, a new pair of 3 ways 432x with LE15A, 375 and 077 or their professionnal equivalent I don't remember.
I found that 4345 were better because of the fourth way in the medium.
But I neglected to upgrade my JBL for WAF reasons.

I search for the exact design of the cabinet. Could you tell me where to find it?

[Chas]

Commencez ici:

http://www.audioheritage.org/vbullet...ad.php?t=11856

[Mr. Widget]

But I neglected to upgrade my JBL for WAF reasons.

Guess you relieved yourself of that problem?

I am still waiting to hear of a member building a pair of 4345 clones and use the 375(2440) in lieu of the 1" driver.


Widget

[grumpy]

Just picked up some 2311's, so 4345 "clones"? no, but I now have all of the
components needed to put together such a beast, with 2123's and more
recent 4" drivers (2446 w/2450SL diaphragms)... too many changes to do
a direct 242x vs. 2440/375 based 4345 comparo, but that's as close as I'll
ever get.

As always, I have no excuse but time prioritization and a good flushing of
accumulated junk in the garage (re cabinet saw access).

As you might imagine, there are a few threads I'm following with much
interest.

[boputnam]

...Or you could just go digital and quad amp.

That has been a very distracting thought of late. I stalled with the problems/isses of using/making appropriate: crossover filter types and slopes; voltage drives; and amp selections. And, where to rack all that gear. And-and, penetrating the cabinet to make the connections.

...My only beef with the 2122H is the foam surround. It's a very nice termination, arguably better than the 2123H rolled surround, but it will rot over time.

Ah, don't we all...

Thanks 4313B - for the thorough response.

+1

I now have all of the components needed to put together such a beast....

As you might imagine, there are a few threads I'm following with much
interest.

Cool!

[robert2k]

Hi, your project makes me very impress, but it’s possible so you can post some spec,
Internal volume for 2245h woofer? Diameter of those 3 ports (I guess 4”) and length of tubes? Also did you use only 1” mdf with bracing?
I’m planning build similar project with 2245h woofer.
Thank you,

Robert

[boputnam]

Hi, Robert...

Most of what you seek can be found in the 4345 Enclosure Plans.

Also, Searching for the numerous threads discussing the 4345 will provide much discussion of the cabinet, drivers and variants.

[BMWCCA]

Heather put this link thread together that might help:

http://www.audioheritage.org/vbullet...d.php?p=171841

[dkalsi]

Not yet. I've still got two pairs of 3155's sitting here looking at me. I can't believe it is already January 12th. I just lost a whole freakin' week.

Hey 4313B,

Hope all is well and hope that things are turning around for the better in 2010. Just wanted to follow up and see whether you had the opportunity to develop the crossovers for the 4345 (not trying to be annoying here - just simply checking in). I'm pretty close to completing the cosmetics and was hoping to start ordering crossover parts sometime in the near future. If no updates, no big deal.

Cheers,
Dhar

[4313B]

Yep, here we are in February already but work hasn't slowed down at all which means I have a job for a little while longer!

I really need to get the networks done so I can sell these 4345 clones and make room in my family room for the family! I'm going to sell off all my JBL systems and components except maybe my Arrays. I haven't decided on those yet. I'll definitely keep the Tannoy HT system that replaced the JBL 4430/4406 system years ago.

[4313B]

I wanted to go ahead and express interest in the systems you might be selling off - especially if you decide to sell any large studio monitors (i.e. 43XX).

I haven't decided what I am going to do for sure yet. I just know that I can't keep these large loudspeakers. My options are to part them out, sell them in the U.S. via local pickup only, or ship them to Japan where I can rest assured that they will be greatly appreciated. I'm leaning towards the parting out scenario if only because it is the least hassle.

[BMWCCA]

I'm leaning towards the parting out scenario if only because it is the least hassle.

That would truly be a shame!

Ohio's not that far from me. Hmm, in fact my wife is driving through Ohio even as I'm typing this...

[spkrman57]

I might have an interest in the empty cabinets........

Ron

[opimax]

Maybe list local pick up 1st and see what goes. I am not sure If I have an interest but if I do going to Ohio for pick up is not an issue.. well if I could get out of the driveway...how much snow out your way?

Mark