JBL Performance Series

[rdgrimes]

Additionally:

In the “Separated” position,
the PS1400 provides an
electronic 300Hz rolloff for the
subwoofer, which should be
augmented by the low-pass
crossover in the external
audio/video receiver or
processor. In this mode, the
PT800, whether or not it is
stacked with the PS1400,
should be given only a highpassed
amplifier signal. That
signal should be crossed over
at 80Hz.

This proves that the PT800 does not have a 130hz crossover..

The passive 130Hz filter is ALWAYS working on the PT800 output, period. (assuming that filter is actually at 130Hz). So according to the above quotes, if the PT800 is connected to the output posts on the PS1400 it is running on a 130Hz filter regardless of the position of the switch. The switch then ONLY effects the input to the sub. This is really the only explanation that makes any sense. The manual is poorly written, and the reference to the 80Hz crossover requirement is meant for when the PT800 is NOT being fed from the PS1400's output posts.

[Titanium Dome]

Fellas, this is all that's in there.

[pathfindermwd]

The passive 130Hz filter is ALWAYS working on the PT800 output, period. (assuming that filter is actually at 130Hz). So according to the above quotes, if the PT800 is connected to the output posts on the PS1400 it is running on a 130Hz filter regardless of the position of the switch. The switch then ONLY effects the input to the sub. This is really the only explanation that makes any sense. The manual is poorly written, and the reference to the 80Hz crossover requirement is meant for when the PT800 is NOT being fed from the PS1400's output posts.

Yep, yep, yep! Exactly! The manual is poorly written. For example, it does not clearly explain that the electronic XO is for line level input in "normal" mode, docked and un-docked explanations have little to do with it. The passive XO is "in line" to the PT800 and must be used when speaker level signal is engaged and passed on, regardless of switch position. And, if "separated" is engaged, the sub (LE143) will play on to 300hz unless an eternal XO is used. The switch ought to say 130hz/300hz. The 130hz passive XO should have been put in the PT800, space not an issue, and therein lies the confusion, I think. I don't know why they didn't just say that if used alone the PT800 should have a 130hz crossover signal, though pointing it out is moot since we have long ago gone over the fact that the PT800 will not play below 80hz and a XO is really not needed. I played mine at full signal, no problem, there is not much bass there...

Can we call this one solved?

[jblsound]

The passive 130Hz filter is ALWAYS working on the PT800 output, period. (assuming that filter is actually at 130Hz). So according to the above quotes, if the PT800 is connected to the output posts on the PS1400 it is running on a 130Hz filter regardless of the position of the switch. The switch then ONLY effects the input to the sub. This is really the only explanation that makes any sense. The manual is poorly written, and the reference to the 80Hz crossover requirement is meant for when the PT800 is NOT being fed from the PS1400's output posts.

Why would the 130 hz filter be working when the PT800 is playing down to 80, when connected to a signal from the AVR which has the XO set to 80?
I can certainly see the 130 filter in the circuit when the internal XO is used.

[jblsound]

Yep, yep, yep! Exactly! The manual is poorly written. For example, it does not clearly explain that the electronic XO is for line level input in "normal" mode, docked and un-docked explanations have little to do with it. The passive XO is "in line" to the PT800 and must be used when speaker level signal is engaged and passed on, regardless of switch position. And, if "separated" is engaged, the sub (LE143) will play on to 300hz unless an eternal XO is used. The switch ought to say 130hz/300hz. The 130hz passive XO should have been put in the PT800, space not an issue, and therein lies the confusion, I think. I don't know why they didn't just say that if used alone the PT800 should have a 130hz crossover signal, though pointing it out is moot since we have long ago gone over the fact that the PT800 will not play below 80hz and a XO is really not needed. I played mine at full signal, no problem, there is not much bass there...

Can we call this one solved?

With an acoustical XO created by the sealed .3^3 box if the slope is 24db/octave, then @ 40 hz its -30db. So therefore you will not hear any output. The fact the manual says not to apply a full range signal is not really needed. How the PT800 works is just the same as the old L212, the sealed box is providing the acoustical XO, although with the L212 only having a 12db/octave slope you do get some bass @ 35hz.

[pathfindermwd]

Fellas, this is all that's in there.

I saw that too. What does this mean to the average consumer though? Anyway, it still doesn't seem to clearly differentiate between the electronic XO and the Passive XO in both/either mode.

They say that life is in the journey, not the destination, maybe by doing it all wrong, they helped us to get it all right..

[pathfindermwd]

With an acoustical XO created by the sealed .3^3 box if the slope is 24db/octave, then @ 40 hz its -30db. So therefore you will not hear any output. The fact the manual says not to apply a full range signal is not really needed. How the PT800 works is just the same as the old L212, the sealed box is providing the acoustical XO, although with the L212 only having a 12db/octave slope you do get some bass @ 35hz.

Makes sense but I thought it was the driver limitation..

[jblsound]

Makes sense but I thought it was the driver limitation..

Its the combination of a particular driver mounted in a particular sized sealed box. Of coarse, if one adds a port then the entire equation changes.
And ever since we've had AVRs & pre/pros everyone just thinks you have to have an electronic XO for both the mid-bass and sub, or you blow up the mid-bass driver. One of the original sat/sub systems, the L212, back then there were no AVRs with built-in XO.
And the 112A in its sealed box had a natural roll off @ 70 hz, and one octave lower, 35 hz, its -18db. I have run both the PT800 and L212 full range with the subs off, never had a problem. If either were ported, probably would have blown both up years ago, trying that.

[rdgrimes]

Why would the 130 hz filter be working when the PT800 is playing down to 80, when connected to a signal from the AVR which has the XO set to 80?
I can certainly see the 130 filter in the circuit when the internal XO is used.

I'm not concerned with "why", but the passive filter is ALWAYS in the circuit for the PT800 output, so if you want to run the PT800 down to 80Hz it must not be connected to a PS1400.

[jblsound]

I'm not concerned with "why", but the passive filter is ALWAYS in the circuit for the PT800 output, so if you want to run the PT800 down to 80Hz it must not be connected to a PS1400.

Yes, I see that. The two can also be physically connected, but not electrically, and run "bi-amp" where the PT800s receive down to 80 and the PS1400 getting bass & LFE.
Now that I think a bit more of the 130 filter & receiving a signal to 80, not really any different than any other sub that only has a 'sub in' and not a LFE or LFE switch. In which cases, one turns up the sub's XO all the way to the top, usually 150 hz, to get it out of the way of the AVR's 80 hz XO.

[Titanium Dome]

I saw that too. What does this mean to the average consumer though? Anyway, it still doesn't seem to clearly differentiate between the electronic XO and the Passive XO in both/either mode.

They say that life is in the journey, not the destination, maybe by doing it all wrong, they helped us to get it all right..

For those pondering these mysteries, just remember, "selectable" isn't the same as "variable."

[rdgrimes]

It's good to know however that simply switching the PS1400 to "separated" mode does not take that 130Hz filter off the PT800 output. I learned something.

It's very easy to bypass that filter if someone wanted to have them docked but no filter. Can't imaging why, but its possible.

One wonders though, just what the "separate" setting really does in the PS1400. Apparently it applies a 300Hz roll-off in the "separate" position and a 130Hz crossover in the "normal" position. Most likely this setting has no effect on the LFE input.

And the "LF Gain" adjustment is only affecting the sound below 130Hz in the "normal" position, but what's it doing in the "separate" position, is it affecting everything up to 300Hz? Inquiring minds want to know.

[jblsound]

60 years ago, it was, The Shadow Knows. In this case, The Mastermind Knows: GT.

[pathfindermwd]

It's good to know however that simply switching the PS1400 to "separated" mode does not take that 130Hz filter off the PT800 output. I learned something.

It's very easy to bypass that filter if someone wanted to have them docked but no filter. Can't imaging why, but its possible.

One wonders though, just what the "separate" setting really does in the PS1400. Apparently it applies a 300Hz roll-off in the "separate" position and a 130Hz crossover in the "normal" position. Most likely this setting has no effect on the LFE input.

And the "LF Gain" adjustment is only affecting the sound below 130Hz in the "normal" position, but what's it doing in the "separate" position, is it affecting everything up to 300Hz? Inquiring minds want to know.

the manual says:

This control only affects all
information being received by
the speaker-level input.

So for true LFE line in, it wouldn't do anything I guess...

[jblsound]

the manual says:

This control only affects all
information being received by
the speaker-level input.

So for true LFE line in, it wouldn't do anything I guess...

But when set to separate, and all bass is sent to the LFE input, the LFE control will operate all bass info.