Re: [time-nuts] COMPLETELY off topic - but I know you'll read it anyway.
In message [EMAIL PROTECTED], Jim Palfreyman writes: Do I run each 8 ohm speaker on its own 500W channel? or Do I run in bridged mode and put the two speakers in parallel onto the 1000W amplifier? Unless the two speakers are _very_ identical, including length and type of cabling from the amplifier, I will recommend against running them in parallel. As former sound technician I will also say this: run them on separate channels, if you loose one channel, you don't loose your sound entirely. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] COMPLETELY off topic - but I know you'll read it anyway.
-Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Bruce Griffiths Sent: Saturday, October 11, 2008 7:24 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] COMPLETELY off topic - but I know you'll read it anyway. Jim Palfreyman wrote: OK I have an interesting but simple problem that has nothing to do with time. But I'm sure someone on this list will know. And besides I can't be stuffed finding another list with such a good S/N ratio. In my spare time I play in a band. I have a 1000W amplifier that can be either two 500W stereo channels or a single 1000W mono running in bridged mode. (Basically one channel amplifies the upper part of the sine curve and the other the lower.) Thats not an accurate description of how bridged amplifiers work. The load is connected between the 2 outputs which are 180 degrees out of phase. This doubles the available voltage swing across the load. For a given load, this quadruples the power (provided neither of the amplifiers goes into current limit). The amp can drive speakers down to 4 ohms. 4 ohms in bridged mode? Or 4 ohms in single ended mode? I have two 8 ohm speakers. The source is mono. Do I run each 8 ohm speaker on its own 500W channel? or Do I run in bridged mode and put the two speakers in parallel onto the 1000W amplifier? Any takers? Regards, Jim Bruce Jim, Since your amplifier is specified at 1000W bridged and 2x500W non bridged, that seems to indicate that the amp would be current limited (otherwise you could get 200W in bridged mode), so in bridged mode, you are expected to use speakers with 2ximpedance specified for non-bridged operation. You say the amplifier can drive speakers down to 4 ohms, but is that the impedance where it can deliver 500W non-bridged? If so, you will need 8 ohm impedance to get 1000W bridged. You can't get there with two 8 ohm speakers, unless you use a transformer. Since the power is likely to be the same if you bridge the amplifier and put the speakers in series, or drive each speaker with it's own channel, I would recommend the second (each speaker on it's own output, non bridged operation) as it will probably have lower distortion. Didier ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] COMPLETELY off topic - but I know you'll read it anyway.
If 500W are specified for a 4 ohm load, you will only obtain 250W for each channel over a 8 ohm speaker. In bridged mode, it is not true that basically one channel drives the upper part of the sine and the other the lower: they operate in push-pull, supplying each side of the speaker with opposite phases so you will obtain the double peak-to-peak voltage value over the load than in the single ended configuration. Double voltage would mean four-times power, so the amplifier surely is not rated for the same load in bridged mode than in single-ended two-channel mode. If minimum load for each channel is 4 ohm in single-ended mode, usually it is 8 ohm for two channels in bridged mode. So if you have 8 ohm speakers... use it in single ended mode (better reliability also, as Poul-Henning pointed), and you will get 250W per channel. In brigde mode, you could only put the two speakers in parallel if the amplifier is rated for 4 ohm loads in bridged mode. Regards, Javier Jim Palfreyman escribió: OK I have an interesting but simple problem that has nothing to do with time. But I'm sure someone on this list will know. And besides I can't be stuffed finding another list with such a good S/N ratio. In my spare time I play in a band. I have a 1000W amplifier that can be either two 500W stereo channels or a single 1000W mono running in bridged mode. (Basically one channel amplifies the upper part of the sine curve and the other the lower.) The amp can drive speakers down to 4 ohms. I have two 8 ohm speakers. The source is mono. Do I run each 8 ohm speaker on its own 500W channel? or Do I run in bridged mode and put the two speakers in parallel onto the 1000W amplifier? Any takers? Regards, Jim ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Javier HerreroEMAIL: [EMAIL PROTECTED] HV Sistemas S.L. PHONE: +34 949 336 806 Los Charcones, 17AFAX: +34 949 336 792 19170 El Casar - Guadalajara - Spain WEB: http://www.hvsistemas.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] COMPLETELY off topic - but I know you'll read it anyway.
Thanks folks for your quick replies. I've dug out the manual and even though the specifications say it can do 4 ohms in bridged mode, there is another statement that says it doesn't recommend it. Here is what it says about bridged mode: The A channel handles the positive voltage and the B channel becomes the negative, thus doubling the output voltage swing. Needless to say, Poul's comment regarding running them as two separate channels because if one fails I'll have another as a spare is the clincher for me. Being from an IT background - backup is all important. Thanks folks! 2008/10/11 Javier Herrero [EMAIL PROTECTED] If 500W are specified for a 4 ohm load, you will only obtain 250W for each channel over a 8 ohm speaker. In bridged mode, it is not true that basically one channel drives the upper part of the sine and the other the lower: they operate in push-pull, supplying each side of the speaker with opposite phases so you will obtain the double peak-to-peak voltage value over the load than in the single ended configuration. Double voltage would mean four-times power, so the amplifier surely is not rated for the same load in bridged mode than in single-ended two-channel mode. If minimum load for each channel is 4 ohm in single-ended mode, usually it is 8 ohm for two channels in bridged mode. So if you have 8 ohm speakers... use it in single ended mode (better reliability also, as Poul-Henning pointed), and you will get 250W per channel. In brigde mode, you could only put the two speakers in parallel if the amplifier is rated for 4 ohm loads in bridged mode. Regards, Javier Jim Palfreyman escribió: OK I have an interesting but simple problem that has nothing to do with time. But I'm sure someone on this list will know. And besides I can't be stuffed finding another list with such a good S/N ratio. In my spare time I play in a band. I have a 1000W amplifier that can be either two 500W stereo channels or a single 1000W mono running in bridged mode. (Basically one channel amplifies the upper part of the sine curve and the other the lower.) The amp can drive speakers down to 4 ohms. I have two 8 ohm speakers. The source is mono. Do I run each 8 ohm speaker on its own 500W channel? or Do I run in bridged mode and put the two speakers in parallel onto the 1000W amplifier? Any takers? Regards, Jim ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Javier HerreroEMAIL: [EMAIL PROTECTED] HV Sistemas S.L. PHONE: +34 949 336 806 Los Charcones, 17AFAX: +34 949 336 792 19170 El Casar - Guadalajara - Spain WEB: http://www.hvsistemas.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] COMPLETELY off topic - but I know you'll read it anyway.
Jim Palfreyman wrote: OK I have an interesting but simple problem that has nothing to do with time. But I'm sure someone on this list will know. And besides I can't be stuffed finding another list with such a good S/N ratio. In my spare time I play in a band. I have a 1000W amplifier that can be either two 500W stereo channels or a single 1000W mono running in bridged mode. (Basically one channel amplifies the upper part of the sine curve and the other the lower.) Thats not an accurate description of how bridged amplifiers work. The load is connected between the 2 outputs which are 180 degrees out of phase. This doubles the available voltage swing across the load. For a given load, this quadruples the power (provided neither of the amplifiers goes into current limit). The amp can drive speakers down to 4 ohms. 4 ohms in bridged mode? Or 4 ohms in single ended mode? I have two 8 ohm speakers. The source is mono. Do I run each 8 ohm speaker on its own 500W channel? or Do I run in bridged mode and put the two speakers in parallel onto the 1000W amplifier? Any takers? Regards, Jim Bruce ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] COMPLETELY off topic - but I know you'll read it anyway.
OK I have an interesting but simple problem that has nothing to do with time. But I'm sure someone on this list will know. And besides I can't be stuffed finding another list with such a good S/N ratio. In my spare time I play in a band. I have a 1000W amplifier that can be either two 500W stereo channels or a single 1000W mono running in bridged mode. (Basically one channel amplifies the upper part of the sine curve and the other the lower.) The amp can drive speakers down to 4 ohms. I have two 8 ohm speakers. The source is mono. Do I run each 8 ohm speaker on its own 500W channel? or Do I run in bridged mode and put the two speakers in parallel onto the 1000W amplifier? Any takers? Regards, Jim ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
