4350 Crossover Q's

[Audionutz]

G'day all from down here in Oz.

I have a pair of 4350's and wondered if the knowledgeable souls that inhabit this board would assist .....

I've owned them now for some months - powered by Crown D150 on bass and a pair of Marantz MA-24 30 wpc Class A Monoblocks on the top ends.

Basically, in a fit of exuberance over the weekend and fuelled by a gathering of like minded Audio mates, we tried placing them vertically. Didnt work to my satisfaction, either with tweeters inside or outside on the baffles.

Anyway, having gently lowered them back into a more dignified horizontal position last night, I now find I have an imbalance with the speakers.

Center image is shifted noticeably to one side. Have changed amps, connections, all wiring and power supplies, reveresed amps, preamps etc etc . I keep getting back to the speakers themselves. Now, the other noticeable thing is that the attenuator controls on both speakers seem to have far less effect than previously, when I adjust them. This leads me to wonder if the crossover has failed in some way on one, or both ?

If my conclusion is correct and the problem lies within the crossover, I now have the question as to whether to repair, rebuild to standard, or upgrade completely ? I am determined to maintain outward cosmetics, so no cutting or enlarging of holes.

I'd like to know my options before diving into this and also, what sort of improvements to expect with the varuious choices.

All comments, opinions or ideas greatfully considered !

Cheers

'Nutz

[boputnam]

I have a pair of 4350's and ...Basically, in a fit of exuberance over the weekend and fuelled by a gathering of like minded Audio mates, we tried placing them vertically. Didnt work to my satisfaction, either with tweeters inside or outside on the baffles.

Anyway, having gently lowered them back into a more dignified horizontal position last night, I now find I have an imbalance with the speakers.Man, you guys were into the Castle (or 4X, or whatever) pretty healthy! Wish I'da been there! 4350's on-end!!?? :blink:

Anyway, my grab is you should peek inside the quieter cabinet and see if anything was jarred loose. The gizzards of my 4345's are pretty stout and can certainly handle gentle moving around, so I suspect whatever it was that happened is pretty visible.

Hoever, what does not make sense to me is the latter part of your post where you claim the L-pads are less responsive on BOTH cabinets? This makes me suspicious that in your celebratory phase your crossover or amps got re-connected improperly (wrong crossover band pass to the wrong amp or amp to the wrong cabinet connections). I'd start from scratch, taking nothing for granted and do it all fresh. Hell - you might find the vertical orientation was not so bad afterall~!

[Audionutz]

Man, you guys were into the Castle (or 4X, or whatever) pretty healthy! Wish I'da been there! 4350's on-end!!?? :blink:

Anyway, my grab is you should peek inside the quieter cabinet and see if anything was jarred loose. The gizzards of my 4345's are pretty stout and can certainly handle gentle moving around, so I suspect whatever it was that happened is pretty visible.

Hoever, what does not make sense to me is the latter part of your post where you claim the L-pads are less responsive on BOTH cabinets? This makes me suspicious that in your celebratory phase your crossover or amps got re-connected improperly (wrong crossover band pass to the wrong amp or amp to the wrong cabinet connections). I'd start from scratch, taking nothing for granted and do it all fresh. Hell - you might find the vertical orientation was not so bad afterall~!

Right on several counts Bo !

I think we were all a bit ambitious that day :) Social lubricants impart such measures of courage !

I agree next step is to have a peek inside. I only run the bass through the crossover, usually at 290Hz. Mid/highs are running full range off the Monoblocks.

Looking at all the pics from the Japanese sites, looks like most folk there have them in the normal, horizontal position, albeit usually on substantial stands. Not to say there's no other way, but given how fanatical those guys are with their big JBL's I would have though they'd tried them on end and gone back to horizontal ....:dont-know

Cheers

'Nutz

[yggdrasil]

When you had the speakers vertically, did you turn the lenses and slots so they kept their normal orientation?

[Audionutz]

When you had the speakers vertically, did you turn the lenses and slots so they kept their normal orientation?

Yes, we certainly did. Bass was definitely more accurate without the floor reflection, but at the expense of mid/highs. Mids especially became "honky" and distorted no matter what amount of toe in/out was applied. Then we tried them with the tweeters outboard on the baffle and sound was very similar. Center image was almost completely lost, along with midrange definition. I had both of these tuned in reasonably well in the horizontal position, which with some 2 inch blocks, raised the tweeters to just below ear level.

'Nutz

[yggdrasil]

Sorry, had to ask... :p

Regarding the crossovers: I can't remember if there have been posted upgraded networks fort the 4350, you'll have to do a search. And read up on charge coupling before doing anything. It will be worth the effort.

You might get some ideas in a thread by saeman about a vertical 4350 clone he made and called 4351.

Good luck.

[Audionutz]

Sorry, had to ask... :p

Regarding the crossovers: I can't remember if there have been posted upgraded networks fort the 4350, you'll have to do a search. And read up on charge coupling before doing anything. It will be worth the effort.

You might get some ideas in a thread by saeman about a vertical 4350 clone he made and called 4351.

Good luck.


Will do and thanks for the reminder - probably should have tried that first :banghead:

Cheers

'Nutz

[4313B]

Regarding the crossovers: I can't remember if there have been posted upgraded networks fort the 4350, you'll have to do a search. And read up on charge coupling before doing anything. It will be worth the effort.So far I've built six pair of charge coupled 3107 networks. I think they all went to Japan.

[Robh3606]

I agree next step is to have a peek inside. I only run the bass through the crossover, usually at 290Hz. Mid/highs are running full range off the Monoblocks.


Hello Nutz

You are running a full range signal into the amp that feeds the High Frequency section of the cabinet? Why are you not running the top end through the active crossover?? They are a Bi-Amp only cabinet. There is no passive filtering between the 2202 and the woofers.


Now, the other noticeable thing is that the attenuator controls on both speakers seem to have far less effect than previously, when I adjust them.

You should have one per speaker and they only effect the 2405.

I hope you didn't cook them feeding a full range signal into the top end amps.

Rob:)

[boputnam]

I hope you didn't cook them feeding a full range signal into the top end amps.Yikes - me too.


I've owned them now for some months - powered by Crown D150 on bass and a pair of Marantz MA-24 30 wpc Class A Monoblocks on the top ends.So, maybe you ran them this way - at moderate volume - for "months", and then maybe you drove them a bit harder during the "Vertical Party"...?

Ugh - I sure hope this is not the problem. It will be an expensive and systemic repair... :barf:

[Audionutz]

Hello Nutz

You are running a full range signal into the amp that feeds the High Frequency section of the cabinet? Why are you not running the top end through the active crossover?? They are a Bi-Amp only cabinet. There is no passive filtering between the 2202 and the woofers.



You should have one per speaker and they only effect the 2405.

I hope you didn't cook them feeding a full range signal into the top end amps.

Rob:)

Thanks Rob,

When we were setting this up, I tested the signal into the top without a crossover. I got no signal at all through the woofers. I may be wrong, but this seems to suggest that there must be some sort of internal filtering or division between the 2202 and the woofers ....? The reason for doing so was to get the crossover out of the signal path as much as possible. Sounded much better too. The 2405 is still providing sound, which is easily heard. Just the controls seem to have less effect on the 2405 output than previously.

Regards

'Nutz

[Audionutz]

Yikes - me too.

So, maybe you ran them this way - at moderate volume - for "months", and then maybe you drove them a bit harder during the "Vertical Party"...?

Ugh - I sure hope this is not the problem. It will be an expensive and systemic repair... :barf:


Hopefully not. I dont run them too hard at any time really. The rooms just not big enough to sound good at higher spl's. As I said, both tweeters are still producing good clear sound, just there seems to be a discrepancy between them. My "gut" fell is its something simpler like the crossover, or that good 'ole "human error" element. I'll be starting from scratch today/tonight and going through the connections from start to finish.

I am however, a little concerned that there seems to be some worry about running the uppers full range. Perhaps someone/s could clarify that for me ?

Cheers

'Nutz

[BMWCCA]

I am however, a little concerned that there seems to be some worry about running the uppers full range. Perhaps someone/s could clarify that for me ?Well, the upper three elements are designed to handle only the frequencies above the 250Hz crossover point. Your external crossover should cross the woofers at 250Hz as well as the upper section. I would think the 2202 could handle the lower frequencies since it has a huge magnet and a 4" copper voice coil, but that's still not the way it's designed to operate.

Don't know if running full-range could harm the passive crossover in the speaker itself but I'm sure others who build networks can speculate on that point. Regardless of whether you ran it full-range, or not, I can't see how that could have harmed the 2405 unless your amp clipped from running full-range. Perhaps the L-pad has crapped out on you if the only difference you're hearing is in the UHF. But then I once blew an 075 with a low-power amp and JBL told me to check for a "high-frequency oscillation" in the amp. We know the ring-radiators are sensitive to clipping amps. I'm running a D150A-II on the top-end of my 4345s and a DC300A-II for the eighteens, with an electronic crossover set to about 300Hz. I've never harmed a tweeter with too much power. I'm not familiar with your monoblocks. Is it possible they're not up to the task?:dont-know JBL recommends a 200wpc amp for the upper section of my 4345s. Your 4350s are even more robust.

[boputnam]

...I tested the signal into the top without a crossover. I got no signal at all through the woofers. I may be wrong, but this seems to suggest that there must be some sort of internal filtering or division between the 2202 and the woofers ....? Er, not exactly - there is no wiring whatsoever between the Mid/Hi connections and the woofers. Rob's point is, those Mid-/Hi drivers do not expect to see a full-range signal - there is no Hi-Pass (Lo-cut) filter in that signal path. Ideally, you would use a symetrical crossover point at 250Hz - the Mid/Hi signal would roll-off below that point.

Here's a Link to the 4350B (http://www.jblpro.com/pub/obsolete/4350b.pdf) brochure. I'll check our Library to see of the 4350 is there - or pm me your email and I can forward it along.


As I said, both tweeters are still producing good clear sound, just there seems to be a discrepancy between them. My "gut" fell is its something simpler like the crossover, or that good 'ole "human error" element. I'll be starting from scratch today/tonight and going through the connections from start to finish.I sure hope there isn't something smoked in the crossover. This is one of those times a nice friendly human error in cabling would be preferred! :)

[yggdrasil]

If you look here : http://www.jblproservice.com/pdf/Network%20Schematics/3107%20Network.pdf

You'll see that the stock crossover only has a low-pass section feeding the 2202.

Meaning: You need to run your active crossover so that the signal you feed into the top-end are ~250Hz and above, and the signal you feed into the woofers are ~250Hz and below.

[boputnam]

If they do clip and there is a lot of HF hash that's most likely going to end up in the 2405 which is the week link in the driver set as far as power handling. Agreed, the tweets are the first to go...

But, the symptoms you describe are quite strange. In ignorance :D I maintain that the interconnects are mixed and once remedied you might be fine. In the process, I'd sure connect the Hi-pass outputs from the active crossover to the Mid/Hi inputs, as Rob suggests. :yes:

[Audionutz]

Agreed, the tweets are the first to go...

But, the symptoms you describe are quite strange. In ignorance :D I maintain that the interconnects are mixed and once remedied you might be fine. In the process, I'd sure connect the Hi-pass outputs from the active crossover to the Mid/Hi inputs, as Rob suggests. :yes:


Good advice, thanks both Rob and Bo. I can now see how full range into the HF section could be a problem. Basically relying on the 12" mids physical limitations to attenuate the lower frequencies.

Will address that wehn I re-cable everything. Sure hope its a dead connection .........:banghead:

'Nutz

[John]

If you had the full range signal running into the top end of a 4350 you would of noticed a lot of movement from the 2202. Unless you really ran the spl,s up I do not believe you could of damaged anything.:blah:

[Audionutz]

If you had the full range signal running into the top end of a 4350 you would of noticed a lot of movement from the 2202. Unless you really ran the spl,s up I do not believe you could of damaged anything.:blah:


Hardly any movement from the 2202 John - in fact I often looked closely to see if it was even moving !

I suspect connections myself - at least thats where I'll be starting :)

Cheers

'Nutz

[4313B]

I can now see how full range into the HF section could be a problem. Basically relying on the 12" mids physical limitations to attenuate the lower frequencies.Just like any other infinite baffle system. It doesn't have to be a problem. It naturally rolls off at the following rate in its sealed subenclosure: -3 dB at 225Hz, -6 dB at 150 Hz, -10 dB at 95 Hz

[Audionutz]

Just like any other infinite baffle system. It doesn't have to be a problem. It naturally rolls off at the following rate in its sealed subenclosure: -3 dB at 225Hz, -6 dB at 150 Hz, -10 dB at 95 Hz


So its close to the 250hz mark anyway ?

So why all the concern over running a full range amp into them, other than the bandwidth limiting issue on high level transients ?

Now Im really confused (and thats often a regular state of mind for me, so I guess I should be used to it :applaud:)

Clarification anyone please .......?

[boputnam]

Just like any other infinite baffle system. It doesn't have to be a problem. It naturally rolls off at the following rate in its sealed subenclosure: -3 dB at 225Hz, -6 dB at 150 Hz, -10 dB at 95 HzGood point. I recall having a similar discussion about the 2122 in the 4345...

And, at only 30w, nothing should have been damaged (unless the monoblocks went to clip). I sure hope this is a wiring issue...

[4313B]

So why all the concern over running a full range amp into them, other than the bandwidth limiting issue on high level transients ?I have no idea. It just isn't a problem.

It's no different than running a full range amp into an L212 side module and those are only 8-inch drivers.

[Robh3606]

I have no idea. It just isn't a problem.


Your not concerned about the 2202 running past X-max?? If 1.6cubic ft is correct on the volume at 100 watts they run out at about 60hz. They can go out at 30 watts as well except an octave lower.

If you look at a 112A it runs out as well. Did I screw up the volumes on the simulations or are you talking from practical experience?

Rob:)

[speakerdave]

I don't see where you say what your crossover is, but I know that even a very fine one like the Bryston 10B interjects a touch of distancing from the 'be there' effect. So--running the top three elements full range, for household use, is a good choice, in my experience. If you are using one of the JBL PA crossovers 5235, or 552/3, their presence in the line is very audible, but, also, the benefits of the tailored response in the correct 5235 cards is also noticable and almost worth the trade-off. However, with Class A amps I would expect you to hear a veiling effect with any added layer of electronics.

The 2202 is robust and has been used in PA boxes where low bass was not needed. In sealed boxes at household volumes you simply have not damaged them playing them full range.

It's just a guess, but I would try to find some way of checking the level controls. In all your moving things about you may have moved or jarred them off the sweet spot they had settled into on a wiping surface that is actually mostly glazed. You could pull a woofer in each cabinet and disconnect the 2405's, reinstall the woofer and see if the imbalance is still there. If not, that would suggest it is the level controls. If it is still there, the problem is likely in the crossover. Or, this would be a good time to have a Stereophile test CD or similar. You could use it to identify pretty precisely the frequency range where there are differences between the speakers because the image will move to the strong side as you go through the frequency ranges. An audio signal generator or software would work even better.

First, though, I would substitute in another known good amp, just to eliminate that as a possibility.

[Audionutz]

I don't see where you say what your crossover is, but I know that even a very fine one like the Bryston 10B interjects a touch of distancing from the 'be there' effect. So--running the top three elements full range, for household use, is a good choice, in my experience. If you are using one of the JBL PA crossovers 5235, or 552/3, their presence in the line is very audible, but, also, the benefits of the tailored response in the correct 5235 cards is also noticable and almost worth the trade-off. However, with Class A amps I would expect you to hear a veiling effect with any added layer of electronics.

The 2202 is robust and has been used in PA boxes where low bass was not needed. In sealed boxes at household volumes you simply have not damaged them playing them full range.

It's just a guess, but I would try to find some way of checking the level controls. In all your moving things about you may have moved or jarred them off the sweet spot they had settled into on a wiping surface that is actually mostly glazed. You could pull a woofer in each cabinet and disconnect the 2405's, reinstall the woofer and see if the imbalance is still there. If not, that would suggest it is the level controls. If it is, the problem is likely in the crossover. Or, this would be a good time to have a Stereophile test CD or similar. You could use it to identify pretty precisely the frequency range where there are differences between the speakers because the image will move to the strong side as you go through the frequency ranges. An audio signal generator or software would work even better.

First, though, I would substitute in another known good amp, just to eliminate that as a possibility.

Thanks SpeakerDave !

Thats exactly what I needed - a nice, concise logic path to follow. That way I can test and eliminate at each step.

Thanks also for clarifying the full range amplifier question, that had me a tad worried about possible damage.

Are you a fan of upgrading the exiting internal crossovers in a quest for better sound ? Or best to leave them alone if they're working OK ?

Also, my crossover is the Behringer Super X-Pro CX-2310.

Cheers

'Nutz

[Woofer]

.... put everything back the way it was, then go over your interconnects, and just check you have the right plugs in the right sockets, keeping in mind that some sockets can be balanced or unbalanced.
Also take note that no input sensitivity switches have been inadvertently bumped to the wrong position.
And yes, do try running your Active XO for both lows and Mid/highs.
Preferably the 5234 instead of the Bellringer.
I'd hazard a guess that a switch has been knnocked and you're experiencing an impedance mismatch somewhere prior to your mid/hi monos.
:blink:

[4313B]

If you look at a 112A it runs out as well. Did I screw up the volumes on the simulations or are you talking from practical experience?Practical experience.

I have a pair of 10-inch 3-ways (2122H, 2421, 2405) and a pair of 12-inch 3-ways (2202H, 2441, 2405) that I've been using for charge coupled network testing and routinely run them full range. It just isn't a problem. They are no different than any other closed box acoustic suspension or infinite baffle system.



The 12-inch 3-way is unholy loud with any kind of real power. You will damage or destroy your hearing if you misuse them.

[speakerdave]

. . . . Are you a fan of upgrading the exiting internal crossovers in a quest for better sound ? Or best to leave them alone if they're working OK ? . . . .



Mr. Timbers recommends charge-coupling crossovers, so in my opinion you don't need anyone else's advice on that. Read his comments on the 4345 in the systems files. However, that involves twice the number of capacitors twice the size, so it is difficult to do on the original boards. You may be able to do it, however. In this thread 4313B has twice mentioned building replacement 3107 crossovers, which you have. Take that as a hint and discuss it with him via PMs.

[boputnam]

I don't see where you say what your crossover is, but I know that even a very fine one like the Bryston 10B interjects a touch of distancing from the 'be there' effect. I can't say that I have experienced that.


So--running the top three elements full range, for household use, is a good choice, in my experience. However, this will result in a roll-off that is asymmetric with that of the woofer.


Just like any other infinite baffle system. It doesn't have to be a problem. It naturally rolls off at the following rate in its sealed subenclosure: -3 dB at 225Hz, -6 dB at 150 Hz, -10 dB at 95 HzThis is approx ±4dB per octave? which results in a large area of overlap between the two drivers in the region of crossover. IME, that is not desireable - as definition is compromised. But that is personal preference. YMMV...

[4313B]

This is approx ±4dB per octave? which results in a large area of overlap between the two drivers in the region of crossover. IME, that is not desireable - as definition is compromised. But that is personal preference. YMMV...I'm not sure I get your point within the scope of my point.

My point is that a 2202 isn't going to magically blow up just because you run it full range. It just isn't.

The 3-way in the 4315 isn't. The 3-way in the 4343 isn't. The 3-way in the 4344 isn't. The 3-way in the 4344 Mk II isn't. The 3-way in the 4345 isn't. The 3-way in the 4350 isn't. And, finally, the 3-way in the 4355 isn't.

As an example... let's say you have a pair of 4345's in a room that have a real problem at 200 Hz. Well, one potential fix might be to change the crossover frequency between the 2245H and the 2122H from 290 Hz to 200 Hz with both drivers down 9 dB instead of 6 dB.

If any of you guys are reading between the lines the specified crossover frequencies that vary from 250 Hz to 400 Hz for these large format studio monitors can be changed as desired/required... some more than others based on whether or not they have any appreciable bottom end. The 112/2108, 2122 and 2204 do while the 2121, 2123 and 2202 really don't. And the lower you cross them over, or if you let them run full range, then the greater the IMD and HD. (No different than an L212 or PT800 for instance)

Why would you run them full range? Maybe you have an AVR and you want to set the 3-way to LARGE and then add in the low end as desired.

[speakerdave]

. . . . However, this will result in a roll-off that is asymmetric with that of the woofer . . . .

Yeah. I kind of broached that topic indirectly in my post where I mentioned the 5235 and also in suggesting he read Timbers on the 4345, but maybe I just basically let that dog sleep.

[Audionutz]

I can't say that I have experienced that.

However, this will result in a roll-off that is asymmetric with that of the woofer.

This is approx ±4dB per octave? which results in a large area of overlap between the two drivers in the region of crossover. IME, that is not desireable - as definition is compromised. But that is personal preference. YMMV...


IME, with these speakers in this room, the trade off betwen definition on the LF/Mid crossover point is well worth it for the increased purity and definition in the mid/HF that comes from running the Class A Monos full range. Testing it innitially with the HF signal running through the active crossover resulted in an audible clouding and grain. Again, just my personal observations ......

Thanks to all that have responded. I think the question of potential driver damage has been answered clearly. Now its just a matter of deciding which way to go with the crossovers.

It occurs to me that these sepakers have an almost dual personality. They can be made to sound like the most accurate pair of monitors (which I guess is what they were designed to do, after all). Then, with minimal changes, they can sound like the best pair of home stereo speakers !

Anyway, I still am very happy with them.

[BMWCCA]

It occurs to me that these sepakers have an almost dual personality. They can be made to sound like the most accurate pair of monitors (which I guess is what they were designed to do, after all). Then, with minimal changes, they can sound like the best pair of home stereo speakers !
That statement I really don't understand. Do you mean you prefer them being something other than accurate with a flat response? There are plenty of those around already! Or are you just looking for "fake-but-fun"? :D

[boputnam]

I'm not sure I get your point within the scope of my point.

My point is that a 2202 isn't going to magically blow up just because you run it full range. It just isn't. No, I get that. I was just trying to illuminate the OP that when running full range, without a crossover-imposed roll-off to the low end of the 2202, there are "consequences" (if you will...) within the range of crossover. I'm not concerned here with transducer performance (or risk to it), per se, just the impact of that signal path decision on the overall system response. I prefer steeper slopes and symmetrical crossover(s), but that is my taste.


Yeah. I kind of broached that topic indirectly in my post where I mentioned the 5235 and also in suggesting he read Timbers on the 4345, but maybe I just basically let that dog sleep.Yeah, I agree. And, no sleeping dogs here - you and 4313B brought some great topics to light.

It is interesting the "OT" discussions that evolved here...

[yggdrasil]

IME, with these speakers in this room, the trade off betwen definition on the LF/Mid crossover point is well worth it for the increased purity and definition in the mid/HF that comes from running the Class A Monos full range. Testing it innitially with the HF signal running through the active crossover resulted in an audible clouding and grain. Again, just my personal observations ......

Have you tried other active crossovers? Running Class A Monos on a Behringer sounds like a paradox to me.

[Audionutz]

Have you tried other active crossovers? Running Class A Monos on a Behringer sounds like a paradox to me.

Class A Monos are not running through the Behringer, they're running full range.

[Audionutz]

That statement I really don't understand. Do you mean you prefer them being something other than accurate with a flat response? There are plenty of those around already! Or are you just looking for "fake-but-fun"? :D


Neither actually. Let me clarify. There is a certain type of "monitor" sound that is easily reproduced with these. Its flat, dynamic and yet a little "souless". It certainly is able to dissect recordings down to the utmost detail, which is its job. As for listening pleasure though, that leaves something to be desired, to my ears at least.

The second characteristic is their ability to portray the real emotion, slam and impact of a live event - better than anything else I've heard near the price. I have had ruler flat accurate speakers for years. They're fun for a while, but they end up wearing you down. Plus I dont like the way they limit your playings to the best recordings only. I am omnivorous with my musical tastes, so I want to try things I find. I'd still like to be able to enjoy them without critiquing the mix.

Hope this clears it up, but no, Im definitely not into the "fake-but-fun" thing ....yuk ! :barf:

[boputnam]

Class A Monos are not running through the Behringer, they're running full range.Ah... Since it's a Behringer we're talking about, I think running them full range is a very wise choice indeed! :p

:duck:

[Audionutz]

Ah... Since it's a Behringer we're talking about, I think running them full range is a very wise choice indeed! :p

:duck:

Poor old Behringer cops another belting :)

I preferred it over the old JBL crossover, but then again, it probably needed recapping etc.

Im looking for something better of course, but to do the 4350's justice seems like it will take some serious $$'s

Any recomendations that I should put on my "hit list" ??

Cheers

'Nutz

[hjames]

Poor old Behringer cops another belting :)

I preferred it over the old JBL crossover, but then again, it probably needed recapping etc.

Im looking for something better of course, but to do the 4350's justice seems like it will take some serious $$'s

Any recomendations that I should put on my "hit list" ??

Cheers

'Nutz

Why not the try one of the Ashly active crossovers?
A lot of folks here have had success with them, and they are available new or used for a fair price.

[4313B]

Any recomendations that I should put on my "hit list" ??Here are some ideas if you know how to solder:

Projects (http://www.google.com/url?q=http://sound.westhost.com/projects.htm&ei=8LGfSrXXEJSkMInl4eIP&sa=X&oi=smap&resnum=1&ct=result&cd=1&usg=AFQjCNFmxTWlvaJ7BLUqPUqzszI748fy9A)

You can put whatever filter you decide to build into an old 5234A chassis.

Or you can tweak out a 5234A or 5235 like another forum member did. I can't remember who it was but do a search on 5235 and maybe the tweak thread will come up.

***

5235 Mod (http://audioheritage.org/vbulletin/showthread.php?t=21031&highlight=5235)

Yeah, I agree. And, no sleeping dogs here - you and 4313B brought some great topics to light.

It is interesting the "OT" discussions that evolved here...No, you and Rob did in posts 9 and 10. I merely tried to address the concern with running them full range, the point being, there isn't one. I should probably have left it at that.

No, I get that. I was just trying to illuminate the OP that when running full range, without a crossover-imposed roll-off to the low end of the 2202, there are "consequences" (if you will...) within the range of crossover. I'm not concerned here with transducer performance (or risk to it), per se, just the impact of that signal path decision on the overall system response. I prefer steeper slopes and symmetrical crossover(s), but that is my taste.Well unfortunately the passive filters in the 4344, 4345, 4350 and 4355 are anything but.



In any case, it looks like this issue is handled.

[boputnam]

Well unfortunately the passive filters in the 4344, 4345, 4350 and 4355 are anything but.I know, but having tried lesser slopes between the 2245 and 2122H I came-out preferring steeper Linkwitz-Riley - but again, personal choice.


Here are some ideas if you know how to solder...I'm pretty good, but not that confident yet. I suffered a setback recently - went to the lead-free solder. Bad idea. That was no fun. The melting point is higher, and once melted (say, tinning or preparing a socket) getting it to re-melt is damned difficult. I ended-up having to run at a much higher wattage and I like and that has risks... :(

[4313B]

I suffered a setback recently - went to the lead-free solder. Bad idea.Yep. There are certain risks associated with being alive and lead in your solder is one of them.

[Chas]

I know, but having tried lesser slopes between the 2245 and 2122H I came-out preferring steeper Linkwitz-Riley - but again, personal choice.
:(

Same experience over here.:yes::yes:

[Robh3606]

I'm pretty good, but not that confident yet. I suffered a setback recently - went to the lead-free solder. Bad idea. That was no fun. The melting point is higher, and once melted (say, tinning or preparing a socket) getting it to re-melt is damned difficult. I ended-up having to run at a much higher wattage and I like and that has risks... :(

Hello Bo

Very bad idea. Especially on older electronics. The new leadfree solders are not compatable with the older part finishes. So never use a leadfree solder on older electronics. All of the newer part finishes are still compatable with lead solders. If in doubt always use a lead solder.

Rob:)

[yggdrasil]

I have quite a few of these (http://www.diyaudio.com/forums/showthread.php?t=74420&highlight=crossover) boards left if anyone is interested in some soldering.

[Woofer]

Poor old Behringer cops another belting :)

I preferred it over the old JBL crossover, but then again, it probably needed recapping etc.

Any recomendations that I should put on my "hit list" ??

Cheers

'Nutz

Firstly, have 'you know who' have a look at the JBL XO, and yes, have it updated.
It may be the cheapest way out.

Secondly, I'd be tempted to run the whole box (bar the 2405's) Active.
Easy enough to do. Just disconnect the Lows, lo-mid, and hi-mids, and run new wiring to them and then out of one of the ports.
This IS a temporary thing of course while you're in search of a solution that suits you.

I'm used to running PA systems, and I can't see why the same approach can't be used at home.
The amount of flexibility an Active XO gives you will be such a reward for your efforts and nothing needs to be physically changed that would permanently alter the originality of your boxes.
... & try and borrow a DBX DriveRack PA XO. The amount of variables offered should pretty well solve most of your problems.

Just my 2 Bobs worth... :blink:

[4313B]

try and borrow a DBX DriveRack PA XO. The amount of variables offered should pretty well solve most of your problems.Yeah, for those who don't like the sound of a loudspeaker as designed the DSP's can offer greatly expanded alternatives.

[Woofer]

Yeah, for those who don't like the sound of a loudspeaker as designed the DSP's can offer greatly expanded alternatives.

Don't get me wrong....
I'm all for originality, but since nothing is definitive, it doesn't hurt to experiment.
I've found, in my own experience, I generally have a bit of fun fooling around, but eventually I settle on the way things were made in the first place.
Chalk it all down to growing up and learning. ;)

[4313B]

Don't get me wrong...I don't think I did. The DSP's are a heck of alot funner than having to screw around with breadboards and passive filter parts.

[Woofer]

Yeah, for those who don't like the sound of a loudspeaker as designed....
(response trimmed)


Heh heh... I wasn't quite sure if your earlier response was tongue in cheek or not. :o:

[4313B]

Heh heh... I wasn't quite sure if your earlier response was tongue in cheek or not. :o:It wasn't. For example, I didn't much care for the sound of the 4350 as designed. I thought the 4355 was a nice evolutionary follow-up.

[Woofer]

It wasn't. For example, I didn't much care for the sound of the 4350 as designed. I thought the 4355 was a nice evolutionary follow-up.

Not trying to stray OT, but do you think it was the Ports, the XO's or what, that made the difference?
Personally, I think maybe the ports.

[4313B]

Not trying to stray OT, but do you think it was the Ports, the XO's or what, that made the difference?
Personally, I think maybe the ports.1. Greg replaced the 3107 with the 3155.

2. Greg replaced the 2231 with the 2235 (can be accomplished with the C8R2235 recone kit) and redid the ducted port configuration.

3. Greg replaced the 2440 with the 2441 (can be acomplished with the D16R2441 diaphragm).

[Woofer]

1. Greg replaced the 3107 with the 3155.

2. Greg replaced the 2231 with the 2235 (can be accomplished with the C8R2235 recone kit) and redid the ducted port configuration.

3. Greg replaced the 2440 with the 2441 (can be acomplished with the D16R2441 diaphragm).

All easy enough to do, but it would take a hell of a lot of deep thought before one would modify such a rarity by altering the baffle permanently to accommodate the new ports. Even if for the better.
It's a tuffie! :(

[Woofer]

Are you following all of this 'Nutz?
Time to drag the Jigsaw out! :p

[4313B]

All easy enough to do, but it would take a hell of a lot of deep thought before one would modify such a rarity by altering the baffle permanently to accommodate the new ports.I wouldn't bother, the difference in tuning frequency is a couple Hz with the 4350 tuned a bit lower.

For those folks seriously paying attention to all this stuff, the 4350 is tuned to the same frequency as the 4435... Some folks might prefer the sound of the dual 2234H's (with the second 2234H used as a helper woofer) instead of the dual 2235H's... It's just a thought...

[BMWCCA]

I'm trying to follow along and learn something here. But the Library links have a problem. If you click on the 4350A link shown by this picture:

http://www.lansingheritage.org/images/jbl/specs/pro-speakers/thumbs/4355_small.jpg (http://www.lansingheritage.org/html/jbl/specs/pro-speakers/1980-4350b.htm)

it takes you to the catalog for the 4350b as shown in this photo:

http://www.lansingheritage.org/images/jbl/specs/pro-speakers/1980-4350b/thumbs/page1_small1.jpg

which looks an awful lot like the same photo/link to the 4355B here:

http://www.lansingheritage.org/images/jbl/specs/pro-speakers/thumbs/4350b_small.jpg

which opens to the 4355 catalog that shows this catalog cover:

http://www.lansingheritage.org/images/jbl/specs/pro-speakers/1981-4355/thumbs/page1_small.jpg
So, ignoring the link photos being swapped between the two models, did the 4350 have six bass ports and the the 4355 have two larger ones?

:dont-know

[Woofer]

So, ignoring the link photos being swapped between the two models, did the 4450 have six bass ports and the the 4355 have two larger ones?

:dont-know

If by 4450 you mean 4350, then yes, it has six.

[BMWCCA]

If by 4450 you mean 4350, then yes, it has six.
Yep, sorry. I'm a visual guy and all those numbers just get in my way.



Off topic: is there anyway to get the jumbled link photos swapped? It could offend the OCD among us. Thanks. ;)

[4313B]

Off topic: is there anyway to get the jumbled link photos swapped?It was brought up years ago so evidently not.

[Woofer]

You can always go here:
http://www.jblpro.com/products/vintage/index.html
... but it doesn't list the 4350A, only the B.

[Audionutz]

Are you following all of this 'Nutz?
Time to drag the Jigsaw out! :p

Yes indeed ! I'm the one bringing up the rear, coughing and spluttering in the "dust cloud" of information ......

Talk about steep learning curve :D (Actually, after this thread I think it's just gone Vertical)

I dont think Im at that point where I know the speakers well enough to determine which path to take yet. Time will tell, but I think there's more to be done with stands, amplification and sources first. Speaking of which, I have a pair of Nuforce Reference 9.02 Monoblocks passing through this weekend. I intend to try them on the HF but am particularly interested to hear them on the bass. Will post some results next week.

Anyway, for those of you interested, I did find the original problem and yes Bo, you were right on the money with interconnects - as were several others.

Turns out the Marantz monoblocks must have had some oversized, or expandable RCA plugs shoved into them at some time. It's actually pushed the center pin socket back into the RCA. Meaning contact was intermittent at best, but came and went of its own accord, throwing out the center image etc etc. Only discovered with help from here and the invaluable assistance of a pair of rolled up socks, sine wave test CD lots of "jiggling" of wiring ;) As they say, "A trap for young players" and in my case, a lesson well learnt.

Cheers

'Nutz

[Audionutz]

Nearly forgot. Speaking of 4355's, I have been offered first option on a pair that may be coming up in a couple of years. One owner/immaculate apparently. In Australia, but interstate from me, so shipping would be a consideration.

What are folks opinions on the improvements, or differences to the 4350 ?

Are they any more valuable as a collectors item ?

Cheers

'Nutz

[boputnam]

Anyway, for those of you interested, I did find the original problem and yes Bo, you were right on the money with interconnects - as were several others.Very cool! Good for you. FWIW, this place ain't about attribution - it's about solutions. We all relish in your relief!


Speaking of 4355's... What are folks opinions on the improvements, or differences to the 4350 ?Man you are way outa my league. I stalled - faithfully - at the 4345, decades below the model numbers you pursue. I have no more questions or curiousities. I will remain faithfully intrigued by your quest, but only as a voyeur... :o:

But...

For example, I didn't much care for the sound of the 4350 as designed. I thought the 4355 was a nice evolutionary follow-up.So, there you go.

Repeating myself: this thread reminds of the great collateral discussions which evolve from the most seemingly innocent post. I think we all need to go vertical every-once-again...!!

And, sadly...

It was brought up years ago so evidently not....yes. We are acutely aware of this (and other) problems with the Library as it is, and also of the raft of "data" awaiting upload and archiving. This all will occur as soon as we can facilitate it.