--------------- FIDO MESSAGE AREA==> TOPIC: 183 AUDIO Ref: EAB00004 Date: 06/05/97 From: PETER SINCLAIR Time: 01:52pm \/To: ALL (Read 0 times) Subj: help me if you can hello everybody i want to build some speakers for home use and i need to know what size boxes to put them in. i plan to put in a 12" woofer, a 6" midrange and an 82mm tweeter. what size box would be needed for this combo ? any other ideas or suggestions ? please help bye thanx --- Ezycom V1.49b1 00F90031 * Origin: Restless - 8 lines + 23 CDRoms + Live Internet! (3:713/618) --------------- FIDO MESSAGE AREA==> TOPIC: 183 AUDIO Ref: EAB00005 Date: 06/05/97 From: DENNIS JENKINS Time: 02:42pm \/To: WILL THOMPSON (Read 0 times) Subj: Difference in DSS Sys? WT>Dennis was speaking when Will spoke up.... WT>Is there any difference between DSS dishes & receivers made by RCA, DJ> You should check out the 4000 series by Dishnetwork. It's a lot m DJ> VCR friendly and the programming is more reasonable. WT> Thanks, I'm getting quite a bit of feedback suggesting this. WT>How's the audio quality / availability of it? You can look it over at www.dishnetwork.com. I imagine all the dbs stuff sounds and looks the same. The dishnetwork has a better cheaper programming package and the 4000 series receiver has a built in timer like a vcr so that it will change the sat channel and use an IR blaster to put your vcr in record mode and stop mode at the right times. It's pretty nice. DJ --- * PW * sorry no taglines * Origin: The STL CATII BBS (314-351-7150) (314-353-9441/2/3) (1:100/757) --------------- FIDO MESSAGE AREA==> TOPIC: 183 AUDIO Ref: EAC00000 Date: 06/07/97 From: BONNIE GOODWIN Time: 04:11pm \/To: ALAN GLAIT (Read 0 times) Subj: Ficha Cannon Hi Alan, The pin outs of a Cannon XLR type connector are: 1= Ground 2= + 3= - Hope this helps! Bonnie *:> --- HyperMail! v1.22 * Origin: Omni - (916) 388-0905, longest running Sac BBS (1:203/3333) --------------- FIDO MESSAGE AREA==> TOPIC: 183 AUDIO Ref: EAC00001 Date: 06/07/97 From: DAVE HALLIDAY Time: 12:11am \/To: PETER SINCLAIR (Read 0 times) Subj: Re: help me if you can > hello everybody Hi! > i want to build some speakers for home use and i need to know what > size boxes to put them in. > i plan to put in a 12" woofer, a 6" midrange and an 82mm tweeter. > what size box would be needed for this combo ? > any other ideas or suggestions ? There is no simple answer... It is not just the physical size of the speaker. There is also the mass of the cone and the stiffness of the mounting as well as the DC resistance and the electrical impedance of the voice coil. These affect the frequency response of the speaker and the frequency at which it resonates. The speakers have specific mechanical and electrical properities. Each speaker has different properties. You must match these properties to their enclosures. There are books which cover this subject and these characteristics are easy to measure with some basic test equipment ( audio oscillator, voltmeter and some hand-made resistnace guages ) Putting just any speaker into just any box will result in a very spikey, inefficient system. It will work but an inch off in one dimention will make the difference between something OK for background music and something that sings!!! If you have web access, check some of the search engines for "speaker" "build" and see what comes up. Try your library and if there is a college or school near you with a decent science department, they may have a book on speakers in their library. Good luck! --- Via Silver Xpress V4.4 [Reg] * Origin: Grey Matter * Seattle, WA * 1:343/210 * (206) 528-1941 (1:343/210) --------------- FIDO MESSAGE AREA==> TOPIC: 183 AUDIO Ref: EAC00002 Date: 06/07/97 From: BONNIE GOODWIN Time: 10:46am \/To: DAVE BACHMANN (Read 0 times) Subj: Isolation Transformer Hi Dave, -> Bonnie - -> -> The other day you recommended an isolation transformer as a solution -> to a hum problem I encountered when I hooked up cable to TV and tuner -> then connected the TV to the pre-amp. I stopped in at Radio Shack and -> found them, but now have even more questions. My reply was a little short to you in a couple of regards, hopefully, this will clarify some. Ground loops (the usual cause of hum) can be caused from many things and sometimes can be difficult to track down. When hooking to cable TV as an example, which I believe was what you were asking about, many times the ground loop is caused from connecting directly to the cable. Remove the connection and the hum goes away. If this is the case, then an isolation transformer between your cable and reciever should solve this. This is the kind that Radio Shack has and should solve your problem. If the hum is still present when the cable is disconnected then this can get much more difficult to find and solve. Ground loops are where there are more than one path to ground at different potentials. Ground isn't necessarily ground. In the US as an example, primarily for shock safety, ground is referenced to the electrical ground, which isn't necessarily a true ground, but for shock purposes it is. Almost every device made has a three prong grounded plug which creates an effective ground between all units plugged into the wall. Unfortunately, every two wire audio signal also is referenced to ground, which isn't necessarily at the electrical ground which can cause additional noise problems by providing a signal ground that may float around the electrical ground, and a seperate line to carry it. Assuming that every electrical device has a grounded return to the electrical ground providing basically what is called a "star ground" from each device to the ground, the cable from your tuner to your preamp doesn't follow that grounding and can create a ground loop or difference in potential from that electrical ground. How to solve these problems can be very frustrating. Using a three to two prong AC adaptor placing it in line with the AC of an item may illiminate the noise, and many of the power distribution boxes that are commercially used has the ability to selectively lift the power ground from active devices in the system. When you first mentioned your problem, it is quite common to have an interaction between the ground coming from the cable (also at a different potential than your electrical ground and system ground), can cause the noise, that's why I suggested the isolation between the cable and your cable box/tuner. These are usally called baluns and a 1:1 ratio should be fine. Get one with two outputs if you intend to connect to your audio reciever and TV reciever as cable sources. As far as books on audio, there are many, many fine books, on this topic I have at least one that is great called "Grounding and Shielding Techinques in Instrumentation" which has helped me out on some very difficult problems in the past, but the above synopsis will usually get you by. In home audio you always have a ground along with a hot lead any time a signal goes from device to device. Also, the AC usually has a brute force ground which resembles a star grounding system. The signal grounds effectively make a ground loop in such a situation by making a loop between all of the devices in the star creating the difference in potential and thus the noise. Or as I believe in your case, it is coming from the difference in potential between the cable ground, the AC ground and your system ground requiring isolation of the ground on the incoming cable like originally suggested. I have so many books on various aspects of audio that it is difficult to suggest one that will cover most things and yet be easy to understand by someone not electronically versed. Perhaps someone else has some good suggestions from the consumer orientation. Bonnie *:> P.S> Thanks for your comments. I intend to support this echo as long as there remains a Fidonet.. There's getting to be a number of folks that have experienced newsgroups and are coming back to the echos because they suit them better. Something like how vinyl is making a retrocomeback for some people. --- HyperMail! v1.22 * Origin: Omni - (916) 388-0905, longest running Sac BBS (1:203/3333) --------------- FIDO MESSAGE AREA==> TOPIC: 183 AUDIO Ref: EAC00003 Date: 06/07/97 From: BONNIE GOODWIN Time: 10:54am \/To: JOHN ALLEN (Read 0 times) Subj: Re: Website for AUDIO Hey you grump (you said it!), Thanks for your interest in an AUDIO webpage. It will happen at some point, but a little stabilty in the personal life is necessary here first, it has been very unstable around here for the past month or so. Just got the echo stable again from being dropped from the listing. Still recouping from the knee injury and dealing with lawyers, various government agencies, etc.. what a crock! Sheesh. I think that merging the AUDIO echo with a moderated mailing list on the Internet will be a first step towards this goal and am investigating that now. I am also a participant on a number of these kinds of maillists devoted to professional audio and electronic music already and it seems like a great way to go. BTW, there's some interesting stuff going on in there. Such as the 24 bit digital vs. analog discussions which I hope to talk about in here at some time. Thanks John, as always, for your support and concern! Bonnie *:> --- HyperMail! v1.22 * Origin: Omni - (916) 388-0905, longest running Sac BBS (1:203/3333) --------------- FIDO MESSAGE AREA==> TOPIC: 183 AUDIO Ref: EAD00000 Date: 06/08/97 From: DAVE BACHMANN Time: 12:0Sam \/To: BONNIE GOODWIN (Read 0 times) Subj: Isolation Transformer As Bonnie Goodwin said to Dave Bachmann: BG> My reply was a little short to you in a couple of regards, hopefully, BG> this will clarify some. Bonnie - Much thanx for the extended explanation. Based on feedback I received from another member of the echo (Thanx Matt!) I added isolation transformers to each channel. The hum has departed and other than a reduction in volume that is easily handled all is well. BG> P.S Thanks for your comments. I intend to support this echo as long as BG> there remains a Fidonet.. There's getting to be a number of folks that BG> have experienced newsgroups and are coming back to the echos because BG> they suit them better. Something like how vinyl is making a BG> retrocomeback for some people. I agree that there is something "small-town friendly" about FIDO that's missing from the newsgroups. I, too, hope that there's enough flow going through FIDO to keep it alive for some time to come. I truly appreciate the efforts that the sysops put into keeping the individual boards up and the information flowing! Dave ... Flash! George Eastman invents the snapshot camera at 10 PM! Film at 11 --- AdeptXBBS v1.09.50s (FREEWare/2) * Origin: SnoValley Shareware Exchange (1:343/108) --------------- FIDO MESSAGE AREA==> TOPIC: 183 AUDIO Ref: EAD00001 Date: 06/07/97 From: GEORGE WELLS Time: 08:51pm \/To: WILL THOMPSON (Read 0 times) Subj: TURNTABLES > I'm in no great hurry so it'll be here. Know what you mean about > making space for the newer stuff. ;) I've had several high-end TTs > and like > the Linns best. The LP-12 is better than the Axis, once you've I have never owned a high end turntable. Just when I could finally afford one, the CD came along and displaced the audiophile LP. Around 1982 or 1983 I went into a local Hi-Fi shop and tehy were selling all their audiophile recordings at agreatly discounted price. They had several of many titles and only one of many titles. I told the owner that I'd give him a dollar each and take one of every title in the lot. Over the years I had gotten to know him well because I had bought so much stuff from him. I was actually only half serious and half joking with him when I made the offer. He said OK, so I ended up with a big stack of great records. Many of the LP's were DBX encoded. DBX encoded LP's just about died instantly when hte CD was released, even though CD's and CD players offered only mediocre sound at an outrageous price. Later........................ .gw. --- FLAME v1.1 * Origin: Telnet toltbbs.com or call 313-854-6001, Boardwatch #55 (1:234/2) --------------- FIDO MESSAGE AREA==> TOPIC: 183 AUDIO Ref: EAD00002 Date: 06/08/97 From: MATT ION Time: 08:59am \/To: BONNIE GOODWIN (Read 0 times) Subj: Re: Ficha Cannon And so it came to pass, on 06-07-97 16:11, that Bonnie Goodwin spake unto Alan Glait: BG> The pin outs of a Cannon XLR type connector are: BG> 1= Ground 2= + 3= - BG> Hope this helps! You forgot to say "usually". Of course, some equipment reverses the + and - connections... no doubt, just to be different. ------------------------------------------- Love, luck, and lollipops... Matt --- Sqed/32 1.10/unreg * Origin: la Point Strangiato... (1:153/7040.106)