Array 1400 bi amping

[andywin]

Just picked up a pair of Array 1400's today and am wondeering why there is only reference to bi-amping the K2's and not the Arrays in the Project K2 & Array brochure.

The Arrays have separate crossovers for LF & HF/UHF and two sets of terminals with links, so is there any reason Array's cannot be bi-amped?

[Mr. Widget]

Just picked up a pair of Array 1400's today...Congratulations!



The Arrays have separate crossovers for LF & HF/UHF and two sets of terminals with links, so is there any reason Array's cannot be bi-amped?Ask your dealer?

If you use the terminals with two amps you will gain the advantage of being able to match an amp for the bottom and another for the top, however you will still have the myriad of passive components in the signal path... that said, if you remove them, I doubt you'll be successful in dialing the response back in. Those speakers are well balanced and quite neutral from JBL.


Widget

[andywin]

Ask your dealer?

Widget

The UK dealers only repeat what's in the literature and Harman UK seems to have disappeared off the face of the earth.




If you use the terminals with two amps you will gain the advantage of being able to match an amp for the bottom and another for the top, however you will still have the myriad of passive components in the signal path... that said, if you remove them, I doubt you'll be successful in dialing the response back in. Those speakers are well balanced and quite neutral from JBL.


Widget

It's the ability to use a beefier amp in the LF that interests me. I understand that the impedance drops close to 1 Ohm at about 70 Hz which may stress my amp which is a single ended 6083 design that puts out about 19 watts max. initial listening has not highlighted any issues aurally but I really don't want to over-stress this wonderful amp.

Andy

[Hoerninger]

... the impedance drops close to 1 Ohm at about 70 Hz

What is the resource of this statement?
___________
Peter

[andywin]

What is the resource of this statement?
___________
Peter

I should have said 1.9 Ohms which is based upon the article below.

http://www.stereophile.com/reference/707heavy/index.html

[Rolf]

which may stress my amp which is a single ended 6083 design that puts out about 19 watts max.
Andy

19 watts? I believe it is not possible to drive the 1400 properly with no less than 200 watts. One thing tho, is if you only listen at very very low SPL. The more the better.

[Robh3606]

Congratulations on a nice pair of speakers!

Where are you getting 1 ohm from?? They don't go below 5 ohms anywhere on the curve.

http://www.audioheritage.org/vbulletin/showthread.php?t=10643


To Biamp you would have to do extensive modifications to the passive crossover to get it right. It's possible but it's a alot of work. You would have to leave the horn compensation and upper crossover in.


Rob:)

[Rolf]

But I agree, a 19 watt SE amp for the bass seems inadequate. Many modern solid state amps will withstand a two ohm load, some a one ohm load.

A quote from the manual of my power amps:


Rated Power Output (per channel) ............................................ 350WRMS into 8 ohm The 350 has been designed around the industry standard 8 ohm load. The 350 delivers a staggering 350WRMS continuously into 8 ohm loads and 600WRMS into 4 ohm loads. The 350 will also handle complex and 2ohm loads with stability and ease.


Short-Circuit/Overdrive Protection

This system senses if there is a short circuit across the 350 output terminals and disconnects the output to avoid amplifier damage. It also senses if the 350 is being driven outside acceptable operational parameters. An example of this would be driving a 1 ohm
speaker at very high levels.

[Mr. Widget]

Where are you getting 1 ohm from?? They don't go below 5 ohms anywhere on the curve.

http://www.audioheritage.org/vbulletin/showthread.php?t=10643They are talking about "Equivalent peak dissipation resistance". This is a method of describing the interaction of both impedance and phase angle simultaneously... in any event, it would seem the Array 1400 is in good company, the B+W 802D drops even lower.


Widget

[speakerdave]

. . . .

Short-Circuit/Overdrive Protection

This system senses if there is a short circuit across the 350 output terminals and disconnects the output to avoid amplifier damage. It also senses if the 350 is being driven outside acceptable operational parameters. An example of this would be driving a 1 ohm speaker at very high levels.
[/FONT]

Rolf--Unlike a mathematics theorem that is disproved by one counterexample, this statement from the manual for one amp does not apply to all. There are amps stable at one ohm. You wouldn't necessarily want to have one for its sonic qualities. It is also common in the world of car audio.

[Rolf]

There are amps stable at one ohm. You wouldn't necessarily want to have one for its sonic qualities

I know, and I did not bought them for that. Just a comment for andywin's post, regarding 1,9 ohm.

[speakerdave]

I know, and I did not bought them for that. Just a comment for andywin's post, regarding 1,9 ohm.

Yeah--I know I've read about such an amp. Right now the only kind of non-car amp I can find information about that specs that is Mackie and such. The amps won't blow up, but distortion figures are not offered. They must limit current but keep working or something.

[Rolf]

Yeah--I know I've read about such an amp. Right now the only kind of non-car amp I can find information about that specs that is Mackie and such. The amps won't blow up, but distortion figures are not offered. They must limit current but keep working or something.

http://www.perreaux.com/products/prisma/350_-_stereo_power_amplifier/

http://www.perreaux.com/products/prisma/750_-_monoblock_power_amplifier/

[4313B]

Greg graciously addressed this issue at the end of his day today. :)

Bi-amping the JBL Model 1400 Array (http://audioheritage.org/vbulletin/showthread.php?t=23763)

[Robh3606]

Nice!! And Thank You!

Rob:)

[4313B]

Nice!! And Thank You!

Rob:)You're very welcome my friend.

And Greg is the consummate gentleman and scholar. :yes:

[Mr. Widget]

And Greg is the consummate gentleman and scholar. :yes:The hell with that, he's a rock star! :p

That is so cool! Please thank him for us.


Widget

[Hoerninger]

A big thank you to Mister G.T!
____________
Peter

[andywin]

19 watts? I believe it is not possible to drive the 1400 properly with no less than 200 watts. One thing tho, is if you only listen at very very low SPL. The more the better.

Rolf, my initial listening concurs with you. My single ended valve amp that can drive my 4333's and S8's to higher than comfortable levels with deep defined lower notes just folds over in the bass department and sounds more akin to my old L200's.

I dug out an old 50W/channel NAD integrated and tried that, ensuring the soft clipping function was enabled. The bass firmed up beautifully and I have to say that even with this "average" amp these 1400's are astounding.

It's apparent that he NAD amp does not have the capability to really drive these speakers as so It looks like I'm going shopping for a boat anchor.

[andywin]

Greg graciously addressed this issue at the end of his day today. :)

Bi-amping the JBL Model 1400 Array (http://audioheritage.org/vbulletin/showthread.php?t=23763)

I must say I feel quite honored to have my question answered in such detail by the actual designer, thank you Greg.

[Rolf]

Rolf, my initial listening concurs with you. My single ended valve amp that can drive my 4333's and S8's to higher than comfortable levels with deep defined lower notes just folds over in the bass department and sounds more akin to my old L200's.

I dug out an old 50W/channel NAD integrated and tried that, ensuring the soft clipping function was enabled. The bass firmed up beautifully and I have to say that even with this "average" amp these 1400's are astounding.

It's apparent that he NAD amp does not have the capability to really drive these speakers as so It looks like I'm going shopping for a boat anchor.

Driving the 4333 high enough? Yes I believe so, but if you had put on a large amp, playing the same music at the highest level you can do with your single ended, I believe you will have an A-Ha experience.

Old NAD's is in my opinion not suited for JBL's at all. But, that is my opinion, and I have tried them.

[Hoerninger]

Bi-amping the JBL Model 1400 Array (http://audioheritage.org/vbulletin/showthread.php?t=23763)
According to Mr. Timbers proposal I found by try and error a passiv solution for use between OPamp buffers thus no feedback network.
But you will need 150 mH and 100 mH. I do not know which are best suitable, may be Fastron?
____________
Peter

[andywin]

Driving the 4333 high enough? Yes I believe so, but if you had put on a large amp, playing the same music at the highest level you can do with your single ended, I believe you will have an A-Ha experience.

Old NAD's is in my opinion not suited for JBL's at all. But, that is my opinion, and I have tried them.

Using a passive pre with the volume at 10 o'clock was all it needed with the S8's and maybe a little more with the 4333's

[Rolf]

Using a passive pre with the volume at 10 o'clock was all it needed with the S8's and maybe a little more with the 4333's

Not sure what you mean.