Bryston 10B L-R and JBL 4350 translation

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08-15-2008, 03:37 PM
neanderthal

Bryston 10B L-R and JBL 4350 translation

I finally received the Bryston 10B L-R and I gave bryston the serial number and this is what they said about it, ("Its a special Quintesence unit which is set-up with +12dB @ 22.5Hz boost with a 150Hz crossover point.."). The 4350 crossover points if I remember correctly without looking are 250Hz , 1.1KHz and 9KHz.
I know instead of 150Hz I need 250Hz but whats up with the +12dB @ 22.5Hz boost? I really don't think I need the 22.5Hz boost either and the +12db means what?
I also already know Iam going to probably send this back to Bryston to have whatever it needs done, I just think I need to have some general knowledge about what's going on with it.
Maybe a basic electronic coarse is in order. I really don't like to bend everyone's ear about the simplest things I should already know if Iam going to be messing with this stuff but Iam already into this with both feet and need bailed out alittle....well OK alot.
I just don't want to screw up the 4350's and have to redo something a second time out of ignorance. Thanks for any enlightenment on this you can provide for a simple mind.
08-15-2008, 04:25 PM
4313B

Quote:

Originally Posted by neanderthal

whats up with the +12dB @ 22.5Hz boost?

Probably some subwoofer EQ. You don't need it.

You might want to send a PM to Bo asking him about his Bryston.
08-16-2008, 04:05 PM
DAVID POHLER

Bryston 10b-lr

Your new Bryston uses cards to set the low/high pass settings. Go to Brystons web site to download the manual. This is a very nice unit, You'll enjoy it when it's up and running. I currently use the 10B standard, I'd love to try the 10B-LR.

Dave
08-18-2008, 11:03 AM
boputnam

Quote:

Originally Posted by neanderthal

...whats up with the +12dB @ 22.5Hz boost? .

4313B's got it.

Quote:

Originally Posted by 4313B

Probably some subwoofer EQ. You don't need it.

...and likely don't want it!

My grab on "straightforward" active crossovers is, you want them to merely be a crossover, with no imbedded fllters. That is, they should be able to move from one application to another and fit equally well (so long as the same crossover point is employed). Brystons and others like them are very good solutions for installations where the speakers are not changing. This is in contrast to DSP's which marry all manner of system control - everything can be modified.

Quote:

Originally Posted by 4313B

You might want to send a PM to Bo asking him about his Bryston.

Send an email to James Tanner with the info you've received and inquire about resetting the crossover point and removing that bass filter. Since it's likely going to have to go back to Peterborough, you'll need an RA - and, they can help you with shipping info to avoid duty (since it's repair/service).
08-18-2008, 12:34 PM
Andyoz

12dB boost at 22.5Hz sounds a bit insanne to me. That must really suck the power out of the system at the higher bass frequencies that really matter, i.e. above 40Hz.

Bo, why would anyone want that?
08-18-2008, 05:35 PM
neanderthal

Quote:

Originally Posted by boputnam

4313B's got it.

...and likely don't want it!

My grab on "straightforward" active crossovers is, you want them to merely be a crossover, with no imbedded fllters. That is, they should be able to move from one application to another and fit equally well (so long as the same crossover point is employed). Brystons and others like them are very good solutions for installations where the speakers are not changing. This is in contrast to DSP's which marry all manner of system control - everything can be modified.

Send an email to James Tanner with the info you've received and inquire about resetting the crossover point and removing that bass filter. Since it's likely going to have to go back to Peterborough, you'll need an RA - and, they can help you with shipping info to avoid duty (since it's repair/service).

Thanks for the info Bo. The email is sent so I'll wait to hear back from James.
08-18-2008, 07:15 PM
boputnam

Quote:

Originally Posted by Andyoz

12dB boost at 22.5Hz sounds a bit insane to me. That must really suck the power out of the system at the higher bass frequencies that really matter, i.e. above 40Hz.

Bo, why would anyone want that?

Andy, I have no idea. Plus, it's damned hard for a speaker to produce without support from proper cabinet design/tuning. I have never run across a need for that in any system I tune, but truthfully, measurements that low are far from reliable anyway.

It's specific to 0.5 Hz. Somebody's making stuff up.... :blah:
08-18-2008, 11:50 PM
Mr. Widget

Quote:

Originally Posted by boputnam

It's specific to 0.5 Hz. Somebody's making stuff up.... :blah:

If the system has the electrical headroom (watts) along with the requisite thermal and mechanical headroom (a robust driver with enough Xmax) it can make perfect sense in the right enclosure.

The 10B had obviously been set up as a sub crossover.

Widget
08-19-2008, 03:04 PM
neanderthal

Looks like I will have a bryston L-R to sell

Here is the answer I received from the email I first sent to Bryston service USA and not James Tanner. Hopefully James Tanner will have better news. Atleast my bad luck is consistent and not sporadic.At this point it looks as though this one is down the road pending on what james has to say about modifying it.

Bryston Service USA ([email protected])Sent:Tue 8/19/08 2:55

Unfortunately this is an early Quintessence 10B specially built for a
particular application and cannot easily be modified. It is our advice to
look for a standard 10b crossover.
08-19-2008, 05:20 PM
boputnam

I would encourage you to get through to Tanner. Bryston are very proud of their products and look after users pretty well. They can certainly modify that unit, removing the +12dB "bump" filter and change the crossover point, and whatever else, but it will cost. Get an estimate.

At least, call Peterborough and get some tech on the phone. I have emails from at-least four in their organization - they have been very responsive.

Having a Bryston modified far outweighs reverting to any of the alternative product available out there.
08-19-2008, 06:33 PM
neanderthal

Quote:

Originally Posted by boputnam

I would encourage you to get through to Tanner. Bryston are very proud of their products and look after users pretty well. They can certainly modify that unit, removing the +12dB "bump" filter and change the crossover point, and whatever else, but it will cost. Get an estimate.

At least, call Peterborough and get some tech on the phone. I have emails from at-least four in their organization - they have been very responsive.

Having a Bryston modified far outweighs reverting to any of the alternative product available out there.

Thanks for your help and your time Bo. I was going to wait and see what James Tanner says when he gets back with me before I move it. I'd really like to use it,it just suprised me that the first email I got from Bryston before I emailed Tanner was short as it was.
What I got out of it is they didn't want to mess with it. Selling it will be a last resort. I have a M552 and a M553 to fall back on but I think the bryston would be the best choice. As you suggested there will probably be some phone calls before this is a done deal and I throw the flag in.
Thanks again for your time
08-19-2008, 06:37 PM
4313B

Quote:

Originally Posted by neanderthal

it just suprised me that the first email I got <snip> was short as it was.

What I got out of it is they didn't want to mess with it.

Exactly. The first attempt is to see if they can make you go away with minimal effort on their part. It's a common ploy with American companies. I'm not sure why Canadian companies would want to follow suit.
08-19-2008, 07:26 PM
Ian Mackenzie

1 Attachment(s)

It only take minimal effort

This the simplified fix for the Xover filters

Capacitors: Low pass: C1=40n, C2=20n, High Pass: C(ab)=4n7
LP HP HP LP HP HP

FREQ. Ra,Rb R1 R2
249 Hz 22K600 95K300 191K00

The manual and schematics for the unit can be down loaded.

These filters appear to be L-R so be aware the original 4350 card filters were not depending on the version see 5235 manual for details.

You will probably have to Eq the crossover region and mess with the polarity of the high pass amp to get it dead right

If Byston are so lazy (its the Canadian attitude ..trust me) then refer to a local technician. He will find the bump filter without much hastle and sort that.

The unit is too good to sell on.

Enjoy

Ian
08-19-2008, 08:50 PM
John

Quote:

Originally Posted by 4313B

Exactly. The first attempt is to see if they can make you go away with minimal effort on their part. It's a common ploy with American companies. I'm not sure why Canadian companies would want to follow suit.

Bryston is Canadian, the usa contact is just that a contact. All the good stuff happens in Peterborough.:bouncy:

They did a extensive rebuild on my pair of 19 year+ 4B's under warranty. And they even picked up the return shipping:applaud:
08-20-2008, 01:56 AM
4313B

Quote:

Originally Posted by John

Bryston is Canadian, the usa contact is just that a contact. All the good stuff happens in Peterborough.:bouncy:

They did a extensive rebuild on my pair of 19 year+ 4B's under warranty. And they even picked up the return shipping:applaud:

Ah! Ha! :)

Thanks for the post Ian.

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