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#7780 - 07/16/03 03:55 PM Loudspeaker driver protection when bi- or tri-amping
bestbang4thebuck Offline
Desperado

Registered: 03/20/03
Posts: 668
Loc: Maryland
Is anyone using their Outlaw amp(s) in a bi-amp or tri-amp situation, with the loudspeaker driver(s) connected directly to the amplifier output? Without any passive crossover components* between amp and speaker to act as transient or DC protection during power-on and power-off, do you feel the need for additional loudspeaker driver protection beyond the Outlaw amplifiers’ own self-protection scheme?

* electronic crossover between 950 and amp(s) allows passive crossover at loudspeaker to be entirely bypassed.

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#7781 - 07/16/03 05:08 PM Re: Loudspeaker driver protection when bi- or tri-amping
soundhound Offline
Desperado

Registered: 04/10/02
Posts: 1857
Loc: Gusev Crater, Mars
I don't use Outlaw amps, but I do tri-amp actively. I would not put anything in line with the power amplifier's output, as this could cause some of the very problems that active crossovers are avoiding, such as the effect of passive components.

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#7782 - 07/16/03 06:21 PM Re: Loudspeaker driver protection when bi- or tri-amping
stabie Offline
Gunslinger

Registered: 09/21/02
Posts: 93
Loc: Austin, TX US
I tri-amp the 3 front speakers. I use a relay to protect the tweeters from transients. As long as you power down the amp about a minute before you power down the crossovers, I think you'd be ok. The outlaw amps don't seem to have on/off transients. I have a ckt I put together to sequence the power up/down sequence and watch for power fail. I suspect that the only time the relay is needed is on a power fail to keep the crossover thump from the tweeters. You can check http://www.stabie-soft.com/ht.html for a full description. If your interested, I can send you the schematics for the controller.

mike

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#7783 - 07/16/03 07:09 PM Re: Loudspeaker driver protection when bi- or tri-amping
bestbang4thebuck Offline
Desperado

Registered: 03/20/03
Posts: 668
Loc: Maryland
I appreciate your input, gentlemen. I’ve been thinking along the same lines.

I will likely be building the crossover network based on the design at

http://sound.westhost.com/project09.htm

Because I will have the option, I will likely use a lot more capacitance in the +/- 15v power supply of the crossover network than is necessary. That way, if there is a power hit/loss, the crossover will be the last item to stop operating.

I will also likely be putting in relays for the tweeters and a simple sequential power up controller. Thanks, Outlaw, for the way you have instituted the triggers.

I look forward to the ‘very clean sound’ benefits of removing passive crossovers from the signal path.

- Dave

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#7784 - 07/16/03 08:06 PM Re: Loudspeaker driver protection when bi- or tri-amping
soundhound Offline
Desperado

Registered: 04/10/02
Posts: 1857
Loc: Gusev Crater, Mars
One thing to be on the lookout for, and which you seem to be addressing is that when crossovers are turned off, they frequently emit a "chirp". I made a box that contains a bank of capacitors fed from rectified AC from the wall outlet that holds a relay on so the crossover remains powered up for about a minute after I turn everything else off.


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#7785 - 07/17/03 10:46 PM Re: Loudspeaker driver protection when bi- or tri-amping
Jeff Mackwood Offline
Desperado

Registered: 12/19/02
Posts: 427
bestbang4thebuck et al,

I'm just a dumb mechanical / aeronautical engineer so I'll leave the heavy electrical stuff to you pros.

However I wonder why you would not connect all of your low-current components to a UPS - so that there is never an unexpected power loss that affects any of your critical components? I run a pretty hefty one for that reason (and to never have to reset the dang clocks on my VCRs!). When the power goes out, everything but my amps stay powered up - long enough to do a controlled shutdown. (Even the rack lighting is on the UPS so that you can see what you're doing when the lights go out - figured that one out when I did my first test run!)

Regards.

Jeff Mackwood
_________________________
Jeff Mackwood

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#7786 - 07/17/03 11:20 PM Re: Loudspeaker driver protection when bi- or tri-amping
bestbang4thebuck Offline
Desperado

Registered: 03/20/03
Posts: 668
Loc: Maryland
I have considered a UPS also. A UPS was my first most important PC system accessory. If I remember correctly, the manual described the output as far from a clean sine-wave and therefore “bad” for some types of equipment. If you have had no problems with your audio equipment after several minutes on an UPS, then great, it’s a viable option!

- Dave

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