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Rolf
03-12-2009, 01:53 PM
Hi friends.

Does anybody know if it improve the sound from the 2235H by connecting the speaker cable directly to the woofer terminals instead of connecting them to the terminals on the back of the speaker? In that case one bypass the switch for the woofers cables.

As most know, I use bi-amping.

At the same time ... is there any idea to rotate the woofers from time to time??

BMWCCA
03-12-2009, 02:12 PM
Does anybody know if it improve the sound from the 2235H by connecting the speaker cable directly to the woofer terminals instead of connecting them to the terminals on the back of the speaker? In that case one bypass the switch for the woofers cables.In GT's comments on the 4345 and 250Ti he definitely supported getting rid of the switch when bi-amping. Others have suggested it is a weak point.

timc
03-12-2009, 02:12 PM
I would say yes on both.

It's not said you will hear a difference. But you will get the best out of it regardless.

Better to be safe than sorry.



-Tim

Robh3606
03-12-2009, 03:24 PM
What does the schematic show you?? Does anything stay in the circuit when you flip the switch?? Does the Zobel stay in?? If not just go straight in. Switches can always get oxidized and noisey/lossy.

Rotating the woofers?? I don't think so a lot of the mass is concertrated in the mass ring right at the spider. I guess it couldn't hurt but I always get nervous with a screw driver close to those soft foam surrounds.

Rob:)

Allanvh5150
03-12-2009, 04:47 PM
Look at it this way, everytime an electric current flows through a less than solid (push terminal, switch etc) you will get an increase in overall resistance with a corresponding decrese in overall power. I am sure that you will not hear the difference unless the connection is very bad. The only reson manufactures include a connection on thier cabinets is to facilitate ease of connection. If it is easy for you I would go with the direct connection.

Allan.

Allanvh5150
03-12-2009, 06:37 PM
So Allan,

Are you proposing we all drill holes in our much loved jbl boxes and poke a wire in for direct connection.

Oh, I guess we should bypass the driver binding posts as well....LOL
:rotfl::rotfl:

Not at all. Disconnetct the tinsel leads from the binding posts and poke them out through the front of the cone and just hook the cable on there.......;)

No Ian, to be serious, one could always make up a new rear plate and run the cable through that way or put a speakon on the plate. It would be better than original and you could always return the cabinet to stock easily. Even when I have modified crossovers etc in my beloved JBL's I have always removed all the electronics and stored them away and replaced the whole assembly. I never make changes that I cant put back without a trace. But thanks for the concern.:)

Allan.

opimax
03-12-2009, 07:02 PM
Phil,

What switch are you referring to with the 250TI? The original ti and L just have one set of speaker connectors on the back. The TIBQ has 2 inputs for passive biamping but no switch. The only by passing would be the XO and the woofer would run full range which would not be optimal :blink:

Do you know where that post is so I can read it? I am a little confused

Mark

toddalin
03-12-2009, 07:06 PM
Oh, I guess we should bypass the driver binding posts as well....LOL
:rotfl::rotfl:

Well I for one silver solder the spade lugs onto the wires between the terminals and diaphrams on my horn drivers that don't have seals intact. Otherwise, these are just a crimp fitting.

May not help, but couldn't hurt as long as you are careful. Also gives you an oppurtunity to check the foams.

BMWCCA
03-12-2009, 07:14 PM
What switch are you referring to with the 250TI? Do you know where that post is so I can read it? I am a little confusedSorry for the confusion. It was simply a post where GT was discussing the 4345 and made a reference to the 250ti. No suggestion of bypassing anything on the 250ti, just referring to the post in a way most here might remember it. It is here: http://www.audioheritage.org/vbulletin/showpost.php?p=110349&postcount=3

opimax
03-12-2009, 07:44 PM
thx, I remember that post after rereading it.

Makes me want to go tinker and listen!

Mark

Rolf
03-13-2009, 12:46 AM
Confirmed.

As a practical test if you short the woofer wires (inside the stock 4345 box) and have an accurate low ohms meter the DCR is quite significant relative to the output impediance of a modern amplifier. I would expect similar conditions with the 4343. The switches were rotary wiper type as I recall.

In readings of the history/product profiles the biamp switch was a marketing decision.

Its worth bypassing the biamp switch. This will audibly improve performance on not just the lows but the highs. There was a thread somewhere on doing this with a diagram. If you are not planning on selling them carefully install some Speakons or HQ binding posts. Its a lot easier than messing with that switch and you can do a lot better than those old terminals.

Useful link
http://www.audioheritage.org/vbulletin/showpost.php?p=69827&postcount=123

Hi Ian. The only thing I have in my mind to do is to drill a hole at the back of the speaker, take the speaker cable through it, and connect it to the woofer terminals. Not messing with the switch at all. Won't this do?

Allanvh5150
03-13-2009, 12:53 AM
Hi Rolf,

If you run the cable to the 2235, you will bypass the crossover. What is the cabinet? Did I miss something?

Allan.

Rolf
03-13-2009, 12:58 AM
Hi Rolf,

If you run the cable to the 2235, you will bypass the crossover. What is the cabinet? Did I miss something?

Allan.

I use a electronic cross over. (JBL/UREI)

Allanvh5150
03-13-2009, 01:27 AM
I use a electronic cross over. (JBL/UREI)

So it is only a 2235 in a box?

Allan.

hjames
03-13-2009, 02:34 AM
So it is only a 2235 in a box?

Allan.

I believe he is talking about his pair of 4343s ...

What I did with my 4341s is to just make a new rear plate,
put a second pair of binding posts on the rear plate and
tie them directly to the woofer with quality cable. Seemed like an easy approach.

(the picture is from the back of my L200 3-ways but i did exactly the same thing with the 4341s)

Rolf
03-13-2009, 02:42 AM
So it is only a 2235 in a box?

Allan.

Yes, like hjames says it is my pair of 4343's. Just want to bypass the terminals on the back, drill a hole for the cable, and connect the woofer directly, completely bypass the switch.

Rolf
03-13-2009, 02:46 AM
I believe he is talking about his pair of 4343s ...

What I did with my 4341s is to just make a new rear plate and put a second pair of binding posts on the rear plate and tie them directly to the woofer with quality cable. Seemed like an easy approach.

That looks nice, but it is much easier just to drill a hole. You did nothing with the switch, just bypass it, and attach the cables directly to the woofer? Right?

Allanvh5150
03-13-2009, 02:47 AM
Heather is onto it. Unless you want to drill a hole in your original JBL plate, remove it and make a new one. If you use quality connectors you wont need to run the cable in direct. Those wafer switches were a rather bad idea in the first place I think.:)

Allan.

hjames
03-13-2009, 02:59 AM
That looks nice, but it is much easier just to drill a hole. You did nothing with the switch, just bypass it, and attach the cables directly to the woofer? Right?
My 4341s came from a recording studio and they had weirded out the original plates with a funky switch anyway - my work cleaned that all up.

I would recommend a connector over a direct wire from amp to the 2235s - its more practical if you need to move them/open them up and the connector loss should be negligible for the kind of quality part you would buy.

And like Fred says above - you can do a gasket or, lacking that, lay a small bead of silicon seal/caulking on the new rear plate as you close it up to seal the rear plate to the box and keep your bass tight!

Fred Sanford
03-13-2009, 03:54 AM
My 4341s came from a recording studio and they had weirded out the original plates with a funky switch anyway - my work cleaned that all up.

I would recommend a connector over a direct wire from amp to the 2235s - its more practical if you need to move them/open them up and the connector loss should be negligible for the kind of quality part you would buy.

...also easier to make air-tight, to preserve back-pressure for the woofer.

je

BMWCCA
03-13-2009, 07:46 AM
Since my "clone" 4345s were not encumbered by the factory networks, when I installed the custom cc networks inside the box I mounted a dual-binding-post input cup on a board fitted inside the cabinet over the "factory" input/crossover opening using the "stock" T-nuts for the network. Much like Heather, but I'm a fan of dual Pomona plugs so I went with this item from Parts Express:

http://www.parts-express.com/images/item_standard/260-304_s.jpg
It's gasketed and the actual connectors are pretty decent. Best not to repeat the mistakes of using the spade connector lugs and just go with terminated driver-wire ends under the nuts on the back of the banana jacks for a tight connection. Tin, crimp, then solder the crimp to the wire. Should make for a quality connection. I'm not familiar with the 4343 enough to know if the position of the stock network will allow enough clearance for the depth of this input cup but If you need a measurement, I can help with that. I'm assuming the network is attached to the braces at the back of the box. I installed my CC networks at the bottom of the 4345 box and this input cup gives me enough room to get my hand in there to change the battery without having to flip the box on its back and remove the 18" for access. I Originally wanted to use a JBL part (like two-each of Heather's salvaged L60T inputs) but couldn't find any with two pairs of inputs that weren't part of a network (L7, etc).

If you're still using the stock networks, I assume you could disconnect the LF binding posts from the network/switch and wire the woofer directly to them on the inside, or replace them with better binding posts. That would allow you to easily revert to original if you ever wanted to. :dont-know

toddalin
03-13-2009, 10:00 AM
Since my "clone" 4345s were not encumbered by the factory networks, when I installed the custom cc networks inside the box I mounted a dual-binding-post input cup on a board fitted inside the cabinet over the "factory" input/crossover opening using the "stock" T-nuts for the network. Much like Heather, but I'm a fan of dual Pomona plugs so I went with this item from Parts Express:

http://www.parts-express.com/images/item_standard/260-304_s.jpg
It's gasketed and the actual connectors are pretty decent. Best not to repeat the mistakes of using the spade connector lugs and just go with terminated driver-wire ends under the nuts on the back of the banana jacks for a tight connection. Tin, crimp, then solder the crimp to the wire. Should make for a quality connection. I'm not familiar with the 4343 enough to know if the position of the stock network will allow enough clearance for the depth of this input cup but If you need a measurement, I can help with that. I'm assuming the network is attached to the braces at the back of the box. I installed my CC networks at the bottom of the 4345 box and this input cup gives me enough room to get my hand in there to change the battery without having to flip the box on its back and remove the 18" for access. I Originally wanted to use a JBL part (like two-each of Heather's salvaged L60T inputs) but couldn't find any with two pairs of inputs that weren't part of a network (L7, etc).

If you're still using the stock networks, I assume you could disconnect the LF binding posts from the network/switch and wire the woofer directly to them on the inside, or replace them with better binding posts. That would allow you to easily revert to original if you ever wanted to. :dont-know

I use a similar setup for my center channel/subwoofer (upper terminals for center channel and lower terminals for sub). One BIG advantage of the rectangular plate (as opposed to a round one) is that you can remove the four screws, turn the plate at an angle, and push it into the cabinet so that you can remove the back, but leave all of the wires in tact. Then when you replace the back, you can just as easily bring it back out.