--------------- FIDO MESSAGE AREA==> TOPIC: 200 PRO AUDIO Ref: F1Y00000 Date: 01/26/98 From: ANTONY STEELE Time: 06:34pm \/To: ALL (Read 0 times) Subj: Amps Okay guys, it's me again. I've got a question (a couple in fact).. Is anyone still here? :> ..and my other question, With standard stereo amps. They have four speaker outputs on the back. Okay I know it's left+, left-, right+ and right-.. But what I'm wondering is, are the right- and left- always the same? I figure that most of the time they are as headphones mix right- and left-. And one last comment for anyone out there reading this. I have this theory about 'surround'. With my design speaker that I wired into right+ and left+, giving the "monauoral content" left-right, or cheap surround. To make it louder and keep the other speakers at the same volume an amp could be designed to output an small amount of left+ singals out the left- speaker connection and right+ out the right- connection. The overall effect of this would make the standard left & right speakers quieter and my surround speaker louder. Any disagreements ? Would that work? ..only that it's a lot of throuble for not much point, as we could've wired a resister along the left+ and right+ wires of the left and right speakers. cya antony.steele@insanity.bbs.net.nz ... DitchDaDate: drool. ~~~ ReneWave v2.00 [NR] --- xMail 1.00 * Origin: ..I.N.S.A.N.i.T.Y.. (3:770/215.3) --------------- FIDO MESSAGE AREA==> TOPIC: 200 PRO AUDIO Ref: F1Y00001 Date: 01/28/98 From: JASON LAVOIE Time: 11:43pm \/To: ANTONY STEELE (Read 0 times) Subj: Re: Amps AS> With standard stereo amps. They have four speaker outputs on the back. AS> Okay I know it's left+, left-, right+ and right-.. But what I'm wondering AS> is, are the right- and left- always the same? in most home audio the speaker outputs do have a common ground, but in a lot of car audio the - of one side is connected to the + of the other. thus, if you hook across the + of the first and the - of the second you get mono at twice the volume. AS> ..only that it's a lot of throuble for not much point, as we could've AS> wired a resister along the left+ and right+ wires of the left and right AS> speakers. Resistors have the potential to alter the sound somewhat and may not be to your liking. as for your wiring proposal, it sounds theoretically feasible but you never know how an amp is going to react unless you designed it yourself. DEE-JAY --- Renegade v5-11 Exp * Origin: Cranial Disturbance (613)723-9841 (1:163/572) --------------- FIDO MESSAGE AREA==> TOPIC: 200 PRO AUDIO Ref: F1Y00002 Date: 01/28/98 From: AL THOMPSON Time: 05:50pm \/To: ANTONY STEELE (Read 0 times) Subj: Amps In a message to All <01-26-98 18:34> Antony Steele wrote: AS> Is anyone still here? :> Yep. AS> With standard stereo amps. They have four speaker outputs on the AS> back. AS> Okay I know it's left+, left-, right+ and right-.. But what I'm I assume you mean the banana plugs for + (red) and - (black) for each annel? AS> wondering is, are the right- and left- always the same? Always? Dunno. I never say "always" because there's bound to be some oddball esoteric home stereo amp which would prove me wrong. On your typical pro-audio power amp, the two black (negative) connections are common. However, if think you are going to save on speaker cable by using only one conductor for the negative connection, you should carefully consider the current capability of your wire, and also the affect it will have on speaker damping. In an extreme case, you could probably run into IM distortion from the resulting voltage drop on the common wire. In the very least, I would expect severe damping problems. --- GEcho 1.00 * Origin: AEN NEWS - 334-735-0306 (1:18/175) --------------- FIDO MESSAGE AREA==> TOPIC: 200 PRO AUDIO Ref: F1^00000 Date: 01/29/98 From: JOE KOTROCZO Time: 01:02pm \/To: ANTONY STEELE (Read 0 times) Subj: Amps Salut Antony, AS> Is anyone still here? :> Yes. AS> ..and my other question, AS> With standard stereo amps. They have four speaker outputs on the back. AS> Okay I know it's left+, left-, right+ and right-.. But what I'm ondering AS> is, are the right- and left- always the same? Wrong. A stereo amp has _two_ speaker outputs on the back. Left+ and left- is Output No.1, and right+ and right- is output No.2. I'm not sure what you mean by 'the same' but they can't have the same signal. AS> I figure that most of the time they are as headphones mix right- and AS> left-. Huh? I don't understand this sentence. (Sorry, my english is lousy...) AS> And one last comment for anyone out there reading this. I have this AS> theory about 'surround'. With my design speaker that I wired into AS> right+ and left+, giving the "monauoral content" left-right, or cheap AS> surround. To make it louder and keep the other speakers at the same AS> volume an amp could be designed to output an small amount of left+ singals AS> out the left- speaker connection and right+ out the right- connection. AS> The overall effect of this would make the standard left & right speakers AS> quieter and my surround speaker louder. AS> Any disagreements ? Would that work? Gotta refresh my electronics, but I'd say 'no'. bye .... Joe --- * Origin: F.A.T.C. (2:270/20) --------------- FIDO MESSAGE AREA==> TOPIC: 200 PRO AUDIO Ref: F2200000 Date: 02/02/98 From: TERRY SMITH Time: 05:15am \/To: JOE KOTROCZO (Read 0 times) Subj: Broadcast Equipment TS> As to your comment on PBX trunk delivery by TS> carrier, do you know what E-1 TS> is, or PRI ISDN? JK> Uh, if I'm not mistaken, E-1 would be what is here JK> commonly called a 2Mbit line and PRI would be what our JK> telco calls "primary multipley ISDN" with 30 B-channels? 32 64 kbps subchannels, which for PRI ISDN would be 30 B + 2 D. The US adopted 1.536/1.544 Mbps T-1 with 24 64 kbps subchannels based on standards that predate the binary era. That has traditionally been offered y copper pair multiplex, but is often now offered as a digital subchannel of larger fiber optic SONET trunks. Note that T-1 uses an extra 80 kbps sync channel outside the primary subchannels, and some T-1 central office equipment steals one bit from channels 6, 12, 18, and 24, or 12 and 24, or just 24, causing some 7 bit and some 8 it channels, while E-1 AFAIK just allocates entire channels within its 2.048 bps for housekeeping. Are they also commonly offering BRI ISDN as 2 B + D, with 144 kbps total, in your area? JK> My problem is that I'm not familiar with the JK> terminology used by you english speaking folks. What I JK> learned of telecommunications was in german... Germany seems to have a lot more systems which are data only using ISDN, hile the US was a little slow implementing services, but has done well with auto-select dual mode protocols such that voice and data can share the same channels. Even in the US, telephone language confuses a lot of people, as many archaic terms are still used and adapted to things to which they don't really apply. For example, a two pair send-receive fiber optic system is called 4-wire, as was the equivalent in microwave RF carrier systems. ITU-T is certainly kept aware of Bellcore standards. That's the publishing outfit that handles what used to be Bell System, before our courts forced breaking up a single national long distance company (AT&T) integrated with most local exchange carriers. Our FCC also gets to define some terms. JK> Problem is that this stuff is anoyingly expensive over JK> here. But that will hopefully soon change when the JK> telecommunications market in Europe is "liberalized" JK> and the monopolies are forbidden... I've heard in Germany there are times when US made modems have sold for 4 or more times the US price. That seems a bit extreme. TS>> You can sometimes find a phone set which offers TS>> a decent speakerphone TS>> and is compatible with the office phone system, TS>> and modify that using TS>> some transformers and pads to provide isolation TS>> and match levels to the TS>> mic in and from the speaker out. JK>> Compatible? How could it be incompatible? Most businesses in this and many other countries use PBX or electronic key phone systems, and not discrete lines and single line phones. Those require special phones to handle the control data as well as audio from the common electronics. Other systems now use ISDN phones. Terry --- Maximus 2.01wb * Origin: Do it near resonance! (203)732-0575 Derby, CT (1:141/1275) --------------- FIDO MESSAGE AREA==> TOPIC: 200 PRO AUDIO Ref: F2200001 Date: 02/02/98 From: TERRY SMITH Time: 05:39am \/To: JOE KOTROCZO (Read 0 times) Subj: Amps AS> With standard stereo amps. They have four AS> speaker outputs on the back. AS> Okay I know it's left+, left-, right+ and right- AS> .. But what I'm wondering AS> is, are the right- and left- always the same? JK> Wrong. A stereo amp has _two_ speaker outputs on the JK> back. Left+ and left- is JK> Output No.1, and right+ and right- is output No.2. JK> I'm not sure what you mean by 'the same' but they JK> can't have the same signal. Most of the time they are the same, a ground/common return, give or take the I^2*R drop in the amp's internal wiring, and are just separate terminals for hookup convenience. In some amps with bridging circuits, - terminals may be not used in an optional bridging mode, or may be active inverting amp outputs and not commons. In some home amps with switches for two sets of speakers, speakers may be looped in series when both are on, rather than the more common parallel. So, no, they are not always the same, are never entirely identical, though re usually wired together. AS> I figure that most of the time they are as headphones mix right- and AS> left-. JK> Huh? I don't understand this sentence. A headphone jack is tip-ring-sleeve. In bridging amps with headphone jacks, the outputs of the non-inverting hots are tapped and sleeve goes to common, while the inverting amp outputs are ignored. In most amps, the sleeve goes o the same common as the - speaker outputs, though is slightly different as it's a low current lead by comparison. That's not mixing anything. Since headphones are low power and current, separate leads as used on speakers are less important. AS> And one last comment for anyone out there reading this. I have this AS> theory about 'surround'. With my design speaker that I wired into That description was a sort of simplistic surroud concept. Others a lot fancier require active electronics. Terry --- Maximus 2.01wb * Origin: Do it near resonance! (203)732-0575 Derby, CT (1:141/1275) --------------- FIDO MESSAGE AREA==> TOPIC: 200 PRO AUDIO Ref: F2300000 Date: 01/30/98 From: LEIGH PREECE Time: 08:34pm \/To: ANTONY STEELE (Read 0 times) Subj: Amps Hi Antony, 26-Jan-98 18:34:23, Antony Steele wrote to All Subject: Amps AS> Okay guys, it's me again. AS> I've got a question (a couple in fact).. AS> Is anyone still here? :> I've been reading but this is my first contribution. AS> ..and my other question, AS> With standard stereo amps. They have four speaker outputs on the AS> back. Okay I know it's left+, left-, right+ and right-.. But what AS> I'm wondering is, are the right- and left- always the same? Depends on the design of the amp - we have a couple of PA amps at work that have separate L+ and R+ but common speaker grounds, whereas one amp has two individual boards inside and separate L+/R+ L-/R- outputs. AS> I figure that most of the time they are as headphones mix right- AS> and left-. Usually. Till Next time then eh ?, Leigh..... --- Terminate 5.00/Pro * Origin: I wrote it - blame me ! Leigh Preece, Staffs. UK. (2:250/563.4) --------------- FIDO MESSAGE AREA==> TOPIC: 200 PRO AUDIO Ref: F2400000 Date: 02/03/98 From: TERRY SMITH Time: 06:05am \/To: LEIGH PREECE (Read 0 times) Subj: Amps AS> back. Okay I know it's left+, left-, right+ and right-.. But what AS> I'm wondering is, are the right- and left- always the same? LP> Depends on the design of the amp - we have a couple of LP> PA amps at work that LP> have separate L+ and R+ but common speaker grounds, LP> whereas one amp has two LP> individual boards inside and separate L+/R+ L-/R- outputs. That can be the result of very careful design practices, even if the - leads all go back to the same point ultimately. It's also possible to have eparate independant power supplies. AS> I figure that most of the time they are as headphones mix right- AS> and left-. LP> Usually. That's a deceptive answer. Referencing to a common or ground is not the same as somehow combining two active inverting outputs in bridging amps. Terry --- Maximus 2.01wb * Origin: Do it near resonance! (203)732-0575 Derby, CT (1:141/1275) --------------- FIDO MESSAGE AREA==> TOPIC: 200 PRO AUDIO Ref: F2500000 Date: 02/05/98 From: SOUTHERN STAR Time: 04:17pm \/To: ALL (Read 0 times) Subj: Expiration Warning Hello. The Zone 1 Backbone only carries echoes listed in the Zone 1/2 EchoList. It seems that the listing for this echo will expire this month. Thus, it is necessary for the moderator to update its listing if it is to remain on the Zone 1 Backbone. For more information please consult these files: BOFAQxxx.TXT and ELISTxxx.ZIP, where "xxx" is the version number. They are available from most hubs or can be requested from 1:1/201 or 1:396/1. Regards, Zone 1 Backbone Operations --- Harvey's Robot v6.00 * Origin: Southern Star - sstar.com - V.32b/V.34+ - 504-885-5928 - (1:396/1) --------------- FIDO MESSAGE AREA==> TOPIC: 200 PRO AUDIO Ref: F2500001 Date: 02/03/98 From: JOE KOTROCZO Time: 07:11pm \/To: TERRY SMITH (Read 0 times) Subj: Broadcast Equipment Salut Terry, [...] TS> Are they also commonly offering BRI ISDN as 2 B + D, with 144 kbps otal, TS> in your area? Yes, that's what they call "basic ISDN". But it's usually referred to as 128 kbps total, since the user cannot transmit anything on the D-channel. JK>> My problem is that I'm not familiar with the JK>> terminology used by you english speaking folks. What I JK>> learned of telecommunications was in german... TS> Germany seems to have a lot more systems which are data only using ISDN, while TS> the US was a little slow implementing services, but has done well with TS> auto-select dual mode protocols such that voice and data can share the same TS> channels. The german telco had this introductory offer, where they practically gave away ISDN equipment, such as PBXs. And 1 basic ISDN "line" (2 B-channels) is cheaper than 2 analog lines. So obviously it's very attractive for Fidonet sysops. TS> Even in the US, telephone language confuses a lot of people, as many TS> archaic terms are still used and adapted to things to which they don't TS> really apply. For example, a two pair send-receive fiber optic system is TS> called 4-wire, as was the equivalent in microwave RF carrier systems. TS> ITU-T is certainly kept aware of Bellcore standards. That's the publishing TS> outfit that handles what used to be Bell System, before our courts orced TS> breaking up a single national long distance company (AT&T) integrated with most TS> local exchange carriers. Our FCC also gets to define some terms. Over here, every country used to have it's own telecommunications monopoly, whit it's own standard and terminology. Since whe have the European Union, monopolies are no longer allowed, which created and still creates a lot of chaos. But sometime Brussels will stepp in and create new silly standards. As they did with the standardized banana and cucumber. (No joke.) JK>> Problem is that this stuff is anoyingly expensive over JK>> here. But that will hopefully soon change when the JK>> telecommunications market in Europe is "liberalized" JK>> and the monopolies are forbidden... TS> I've heard in Germany there are times when US made modems have sold for 4 or TS> more times the US price. That seems a bit extreme. That was back when equipment to be used on a telephone line had to be certified by a german federal agency as to it's compliancy. It was forbiden and punishable to use uncertified equipment, and certification was very expensive for the manufacturer. Luckily they abandonned that and now only require a CE certification. TS>>> You can sometimes find a phone set which offers a decent speakerphone TS>>> and is compatible with the office phone system, and modify that using TS>>> some transformers and pads to provide isolation and match levels to he TS>>> mic in and from the speaker out. JK>>> Compatible? How could it be incompatible? TS> Most businesses in this and many other countries use PBX or electronic key TS> phone systems, and not discrete lines and single line phones. Those require TS> special phones to handle the control data as well as audio from the common TS> electronics. Other systems now use ISDN phones. Ah, I see. bye .... Joe --- * Origin: F.A.T.C. (2:270/20)