Jbl 4367

[microstrip]

Hello Micro

I don’t think it open pandora’s box at all. I am no stranger to burn in but what are we talking about burn in for electronics of mechanical break in like a loudspeaker. The effects of burn in on electrical components is well understood. There are easilly measureable differences. If you look at the part screening specifications for these parts used for space and military applications there are even delta requirements for selected parameters that if you exceed them the parts cannot be used. There are always shifts but that does not mean they would be audible if used in say an amplifier as an example.

Now with speakers 500 hours of burn/break in?? The only you are breaking in is your mind IMHO. With materials you have beryllium, aluminum, magnesium and titanium used in compression drivers. They are all different in their properties. I like beryllium best. I don’t see it as pandora’s box. Under certain circumstances and uses there will be audible differences but not in all. That is where I make the distinction.

Hello Folsom

I use the older battery method.

Rob

Rob,

You use a dual criteria - you seem to accept that DC biasing improves the capacitors without providing any measurable or scientific evidence - the arguments about similarity to class A /Class B amplifiers are nice literature, but just marketing analogies. Did you read the Greg Timbers comments, that are purely subjective? They are the best we can find about this affair.

There is no burn-in military specification that can be applied to our subjective findings abut components. The best I found was a document about endurance from the 50's that suggests that film capacitors subjected to DC endurance tests seem to have a lower failure rate in the future, but it was not proven.

Part screening and infant mortality are different subjects that use proper science and analysis.

 

[microstrip]

Not sure that I accept "anything".. I need to be proven somehow of the ways capacitor A is better than cap B...

I know of it. You are a real skeptic. The only exception seems to be power conditioning, that is beyond scientific proves.

BTW, apologies if you got the wrong idea, I would never be interested in participating in a debate asking if capacitor A is better than capacitor B. But would happily debate if capacitor A sounds different from B!

 

[Brucemck2]

FWIW, many years ago I swapped out the crossovers in some big B&W speakers, which were considered near state of the art in terms of transparency and dynamics at the time, with upgraded units from North Creek. The replacement crossovers had identical component values and topology. The difference was profound.

http://www.northcreekmusic.com/B-W_Matrix_Crossover_Upgrade/b-w_matrix_crossover_upgrade.html

 

[Robh3606]

Rob,

You use a dual criteria - you seem to accept that DC biasing improves the capacitors without providing any measurable or scientific evidence - the arguments about similarity to class A /Class B amplifiers are nice literature, but just marketing analogies. Did you read the Greg Timbers comments, that are purely subjective? They are the best we can find about this affair.

Hello Micro

Well I have tried it and it sounds better with the DC bias. So from a subjective point of view what's the problem?? From an objective point of view they have a dc voltage on them so you are actually doing something to them. As to why they sound better with the DC applied I really don't know and don't care. Why don't you try it and see for yourself?? You don't have to use expensive parts just get some Solens and give it a shot.

Rob

 

[bonzo75]

FWIW, many years ago I swapped out the crossovers in some big B&W speakers, which were considered near state of the art in terms of transparency and dynamics at the time, with upgraded units from North Creek. The replacement crossovers had identical component values and topology. The difference was profound.

http://www.northcreekmusic.com/B-W_Matrix_Crossover_Upgrade/b-w_matrix_crossover_upgrade.html

The US and UK distrbutors of Analysis Audio, a ribbon magnetostat, sell their speakers with the crossover components changed. They sell the modded speaker as a stock speaker. So the US distri, for example, will list his speakers at 3 price values, the lowest with Mundorf, the highest with Duelund. Don't remember what the middle is. He also sells them as actives. This is because the unmodded Analysis has a higher frequency roll off, and they can boost this as well as the resolution by changing crossovers. The Nordic distributor is planning a similar change to his crossovers

 

[DaveC]

I know of it. You are a real skeptic. The only exception seems to be power conditioning, that is beyond scientific proves.

BTW, apologies if you got the wrong idea, I would never be interested in participating in a debate asking if capacitor A is better than capacitor B. But would happily debate if capacitor A sounds different from B!

I've compared many capacitors used as output coupling caps in my preamps as well as speaker caps. I greatly prefer copper foil caps to any others, but they are not inexpensive. Jupiter's copper caps are among the best at any price imo. The difference vs typical MKP caps is profound.

 

[microstrip]

Hello Micro

Well I have tried it and it sounds better with the DC bias. So from a subjective point of view what's the problem?? From an objective point of view they have a dc voltage on them so you are actually doing something to them. As to why they sound better with the DC applied I really don't know and don't care. Why don't you try it and see for yourself?? You don't have to use expensive parts just get some Solens and give it a shot.

Rob

Thanks, Rob. I am surely going to try it as soon as possible. We must remember that we in order to compare we must have separate sets of identical capacitors - once you apply the DC polarization it remains aurally effective for some time, even after removing the DC.

My main interest in your results is that classical audio measurements I know about failed to find a significant difference in this test if carried with film capacitors and you are reporting an audible and repeatable effect.

For more information on the excellent behavior of film capacitors we can see http://www.cliftonlaboratories.com/capacitor_voltage_change.htm

 

[dallasjustice]

Measurements

I wanted to post some measurements so folks can get a more realistic perspective on what these speakers do. The following is not my normal setup. I listen with active crossovers to subs. So my normal bass is flat to 20hz with a wide sweet spot since I use four subs. I've been PM'd by several folks interested in these speakers. Some asked me about how extended the low end is. You can see from the FR plot that the low end probably -10db at 30hz. That's not bad for a two way speaker for sure. But I would recommend at least two subs to get the full package.

You can also see that these speakers do well with Acourate DSP. The smoothed 1/12 per octave plot shows that the speaker tracks my target curve very well. You can also see that DSP correction can make the time domain very tight so that the two drivers produce a very vertical step. The logsweep was only to 20khz. Note how scary flat the JBLs are from 6khz-20khz!(the downward HF slope is due to the target curve.)

 

[sbo6]

I wanted to post some measurements so folks can get a more realistic perspective on what these speakers do. The following is not my normal setup. I listen with active crossovers to subs. So my normal bass is flat to 20hz with a wide sweet spot since I use four subs. I've been PM'd by several folks interested in these speakers. Some asked me about how extended the low end is. You can see from the FR plot that the low end probably -10db at 30hz. That's not bad for a two way speaker for sure. But I would recommend at least two subs to get the full package.

You can also see that these speakers do well with Acourate DSP. The smoothed 1/12 per octave plot shows that the speaker tracks my target curve very well. You can also see that DSP correction can make the time domain very tight so that the two drivers produce a very vertical step. The logsweep was only to 20khz. Note how scary flat the JBLs are from 6khz-20khz!(the downward HF slope is due to the target curve.)

View attachment 26566

Those are very very good results. Can I ask - with DSP in your setup are you attenuating only or amplifying frequencies also? And if you are amplifying, do you notice any deleterious effects?

 

[dallasjustice]

That's a good question. All DSP correction software I know about uses proprietary filtered response prior to inversion. So it's the way the software filters the original impulse which separates the shitty sounding DSP softwares you normally hear in cheapy AVRs from the most advanced softwares like Acourate. Acourate uses what Uli calls frequency dependent windowing (FDW). IOW, the "aggressiveness" is designed to avoid doing any overcorrection. Also, the FDW can be tailored based on the group delay plot and listening. It's important to not cause any audible pre-ringing.

I only showed a 1/12 per octave plot due to its common usage to help identify basic trends and the corresponding number of notes per octave. However, Acourate gets its inversion from what's called a "psychoacoustic" smoothed result. You'd have to ask Uli how he came up with this smoothed result prior to inversion.

Those are very very good results. Can I ask - with DSP in your setup are you attenuating only or also amplifying frequencies also? And if you are amplifying, do you notice any deleterious effects?

 

[Folsom]

I was in a Harmon dealer room here at Axpona; the dealer said your JBL model has been a hot seller lately.

However while listening to the big boys I did conclude the stock capacitors are a limit on the sound quality. It's a familiar flavor found with other speakers. However I can understand why they don't come stock with upgrades due to cost, and given how far their engineering has already taken them. They're certainly way beyond anything else using those capacitors by leaps and bounds.

 

[dallasjustice]

You are clueless.

I was in a Harmon dealer room here at Axpona; the dealer said your JBL model has been a hot seller lately.

However while listening to the big boys I did conclude the stock capacitors are a limit on the sound quality. It's a familiar flavor found with other speakers. However I can understand why they don't come stock with upgrades due to cost, and given how far their engineering has already taken them. They're certainly way beyond anything else using those capacitors by leaps and bounds.

 

[fas42]

However while listening to the big boys I did conclude the stock capacitors are a limit on the sound quality. It's a familiar flavor found with other speakers. However I can understand why they don't come stock with upgrades due to cost, and given how far their engineering has already taken them. They're certainly way beyond anything else using those capacitors by leaps and bounds.

Folsom, in what way did you feel the quality wasn't quite as optimum as possible?

Thanks,

 

[Folsom]

Well like anything else using those caps it simply sounds slightly smoothed out. This can be a big benefit in many situations when matching to slightly bright equipment. But for the best sound I prefer better caps that have a more honest fringe on all of the sound. During vibrato this is important for strikingly good sound. I posted a link earlier comparing capacitor types and the measurements show that these do intact normalize the wave form a little, as in reduce peaks (please remember this is on a scale so small that it cannot affect say bass dynamics; small enough to be arguable amout difference in performance).

The Harmon big boys project size better than perhaps everything else in their price range at the show. The long standing work that's into how they are designed I wouldn't ignore. But the presentation here with Mark Levinson gear is very macro; a rather honest macro.

 

[fas42]

Thanks for that, Folsom ... :b

 

[FrantzM]

I was in a Harmon dealer room here at Axpona; the dealer said your JBL model has been a hot seller lately.

However while listening to the big boys I did conclude the stock capacitors are a limit on the sound quality. It's a familiar flavor found with other speakers. However I can understand why they don't come stock with upgrades due to cost, and given how far their engineering has already taken them. They're certainly way beyond anything else using those capacitors by leaps and bounds.

Hi

I haven't heard the JBL4367 yet but this seems to be a heavily biased opinion, based on the fact that you were in full knowledge of the caps used in the speakers. Difficult to give it much weight..IMHO

 

[KeithR]

I was in a Harmon dealer room here at Axpona; the dealer said your JBL model has been a hot seller lately.

However while listening to the big boys I did conclude the stock capacitors are a limit on the sound quality. It's a familiar flavor found with other speakers. However I can understand why they don't come stock with upgrades due to cost, and given how far their engineering has already taken them. They're certainly way beyond anything else using those capacitors by leaps and bounds.

you can isolate caps in an unfamiliar system in a hotel room?

 

[Folsom]

It was a large room BTW, not a guest room. It's also important to note that were I needing to guess from the dark about it I wouldn't be able to say which piece of the equipment was using the type of capacitor. It could be the input on the amp or such. However I know it's not because Mark Levison doesn't use caps like them for input. The sound was clearly related to signal, and given ample confirmation about Harmon's use of them it's an easy conclusion. It also sounded more like other speakers using them than in the signal path of the electronics given that the highs didn't see underwhelming.

 

[amirm]

It was a large room BTW, not a guest room. It's also important to note that were I needing to guess from the dark about it I wouldn't be able to say which piece of the equipment was using the type of capacitor. It could be the input on the amp or such. However I know it's not because Mark Levison doesn't use caps like them for input. The sound was clearly related to signal, and given ample confirmation about Harmon's use of them it's an easy conclusion. It also sounded more like other speakers using them than in the signal path of the electronics given that the highs didn't see underwhelming.

The 4736 is not on display at axpona. Which speaker are you talking about?

 

[dallasjustice]

The 4736 is not on display at axpona. Which speaker are you talking about?

Amir,

You are clearly confused. Folsom isn't talking about speakers. He's talking about capacitors.