Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site psivax.UUCP Path: utzoo!decvax!ittatc!dcdwest!sdcsvax!sdcrdcf!psivax!tommie From: tommie@psivax.UUCP (Tom Levin) Newsgroups: net.audio Subject: Re: Help on designing speakers Message-ID: <1055@psivax.UUCP> Date: Mon, 10-Mar-86 16:26:55 EST Article-I.D.: psivax.1055 Posted: Mon Mar 10 16:26:55 1986 Date-Received: Tue, 11-Mar-86 08:40:19 EST References: <3182@sdcc3.UUCP> <33@ur-tut.UUCP> Reply-To: tommie@psivax.UUCP (Tom Levin) Distribution: na Organization: Pacesetter Systems Inc., Sylmar, CA Lines: 87 Keywords: Speaker design (kind of long) In article <33@ur-tut.UUCP> junk@ur-tut.UUCP (Jan Vandenbrande) writes: >.... > I believe many of us have thought about designing speakers >because we ran out of money, thought we good do a better job, like >to tool around etc. > (....) >Still not yet discouraged I kind of looked around how much it would >cost in hardware alone to make my own speakers. It added up to more >than what you would buy in a store. I must disagree. I built a pair of two-way monitors using the best of everything I could find (i.e. Audax bextrene mids, Audax tweeters, mylar caps, "Live Wire", etc.) and the total cost to me (including cabinets and veneer) was under $200.00 a pair! These monitors compare quite favorably (actually better in my opinion) to the Rogers LS35A's. A good friend of mine designed these little beauties (he has also designed amps, preamps, subwoofers, etc.). They have a 3rd-order Butterworth crossover, Thiel-Small cabinet alignments, rounded front edges (reduces diffraction), 3/4" high density particle board, fuses for both the mids and tweets, etc., etc. etc. The bottom line is that they sound EXCELLENT! I am incredibly happy with them! The best part is that *I* built them and I did a more careful job than just about any other speaker manufacturer would do (my opinion). >(....) But the danger is that you don't know what the final >result will be until you connect the speaker to the amplifier. That's why when you are designing you need to have the crossover outside the cabinet so you can fiddle the theoretical values to where they sound the best (at least to your ears). >Add to this the amount of work and design that goes into making all this. >If you don't have access to a whole range of instruments (pressure >mikes [or whatever they are called], netwerk analysers, spectrum analysers, >ossiloscopes, signal generators, anechoic rooms, some machine >where you can do circuit simulation [SPICE for ex.], and a whole lot more) >you are really walking in total darkness, and making wild guesses. Geeeez! What a pessimist ;-). Seriously though, it is a blast to make your own speakers and I wouldn't worry all that much about all them there fancy electronic equipment. Even if you only use the theoretical cabinet volume and "text-book" crossover circuit, the result will probably be better than 99% of the mid-fi junk out there (have you ever looked at the inside of a Fisher loudspeaker????). >The result can be better than what you buy in a store, but it could be >much worse too. Unless you are talking about GOOD speakers (read "Kef", "Rogers", "Linn", etc.) I seriously doubt you could do much worse. >I am not saying that it is totally impossible. I am sure alot of people >tried this and had satisfactory results. But if you want superior results >it might end up a bit involved (and may be a lot of fun too). Building my own speakers was the most rewarding project of my life. >One trick you could use is to "immitate" a speaker you like. Not such a bad idea actually. My friend who designed my monitors did just that when he designed the subwoofer for the satellites. He "immitated" the Audio-Pro B-250 subwoofer (a self amplified beast with 2 Philips 6-1/2" woofers mounted in a "push-pull" configuration). It is probably better than the Audio-Pro model (It has a much more powerful amp of his own design with high quality components) and only cost about $300.00 total (compared to over $1000.00 list for the A.P). >Don't forget that these speaker co.'s usually did a certain amount of >research and have alot of know-how you don't have. ummmm........maybe....naw! (1/2 :-)) To summarize my very biased and opinionated feelings: Most people would be astounded at the lack of science put into mass market speakers (and other stereo gear too). I can't believe the prices on some of these 3 way monsters (you know, the ones with the 15" woofers!). I have looked inside and seen (with my own eyes) 1st order crossovers, or worse yet, straight wire!!!! Also, flimsy, resonating cabinets, inferior speakers, etc. Well, enough rambling. I'm sure this article will create a lot of replies (but hopefully not too many flames). Let the speaker builing begin! -- __________________________________________________________________________ Tom Levin {ttidca|sdcrdcf|logico|scgvaxd|bellcore}!psivax!tommie "Turn it up!!!"