kenratboy Posted March 12, 2003 Share Posted March 12, 2003 I am 100% serious. I saw Parts Express has a box of 32, 8 ohm Pioneer full range drivers for $32 and it got me wondering if I would have some fun making some Bose-like speakers (except, these speakers would be worth a LOT more than Bose ) First, how do you work impedance with 4, 6, 8, etc. drivers? Do you have a X-over only driving a few speakers at a time? Even 8, 32 ohm speakers would get awfully hard to drive. I was wondering, have 16 ohm drivers, and have them triamped (like a multi-room amp) and have three drivers doing the bottom, three for the middle, and three for the top. Have two foward facing and one reverse. I would certainly never abandon REAL speakers, but I am thinking about it for $hits and giggles. But, how do you work a X-over and all that? Quote Link to comment Share on other sites More sharing options...
skonopa Posted March 13, 2003 Share Posted March 13, 2003 I don't think the Bose 901s have a crossover. According to thier website, they come with an external equilizer or "Active Equilizer" as they call it. In fact, the users guide (which can be downloaded in .PDF format from the Bose website), has a big caution symbol with a warning that you must use the Active Equilizer. Basically it is a unit you insert into the tape loop or hook-up through the pre-amp output/amp input. Basically, the short of it is that they use some fancy equilizer tricks to get performance out of the things. You gotta admit - I looked at thier "data sheet", which is basically a four-color glossy. Right at the top - "THE WORLDS MOST ACCLAIMED SPEAKER, REGARDLESS OF SIZE OR PRICE." (thier caps!) HAHAHAAHAH - got any more good fairy tales there guys? Hey, look at that - they got a whole website full of fairy tales! Maybe on a boring weekend, I'll take a drive up to the Bose store at Tyson's Corner. I would actually like to hear a pair of these things. Quote Link to comment Share on other sites More sharing options...
minn_male42 Posted March 13, 2003 Share Posted March 13, 2003 i agree... the bose 4 inch "full-range driver" is a definite POS....i've listened to the 901's without the equalizer hooked up....sounded like vintage AM radio... i sell commercial/paging speakers.....our cheapest speaker is about $10 and they definitely sound like a $10 speaker....what most installers do is to get a good eq and boost the highs and low like crazy to get even an average sound.... the 901's.....maybe should be classified as THE MOST OVER-HYPED SPEAKER IN HISTORY... russ Quote Link to comment Share on other sites More sharing options...
TheEAR Posted March 13, 2003 Share Posted March 13, 2003 If you are looking for information about the B0$e 901 just ask Arttie the one with the nancyboy fetish.He is the lead designer and expert in the as far as the 901 is concerned Quote Link to comment Share on other sites More sharing options...
kenratboy Posted March 13, 2003 Author Share Posted March 13, 2003 Let me rephrase. Where can I get plans on building LINE ARRAY speakers? minn_male42 - what sort of commercial stuff do you sell? Do tell. Quote Link to comment Share on other sites More sharing options...
mike stehr Posted March 13, 2003 Share Posted March 13, 2003 http://melhuish.org/audio/ http://www.t-linespeakers.org/index.html These sites may help Ken. Quote Link to comment Share on other sites More sharing options...
jt1stcav Posted March 13, 2003 Share Posted March 13, 2003 Forget the Bose 901 knockoffs...who cares about buildin' line array speakers and using some damn active equalizer just to get them little drivers to even sound like loudspeakers and not like a speakerphone...LOL! Go to Parts Express and buy yourself some horn drivers and a good woofer to match up with, and build yourself some cool horn loudspeakers, either 2 or 3 way, monitors or towers. Now that would be a rather noble challenge that would spark the interest of every single Klipschan here in these Forums! If I had the knack with power tools, knew a thing or two about loudspeaker design (and was mechanically inclined), I'd attempt to build a little 2 way horn loaded monitor for my home/office. If it even sounded remotely close to anything Klipsch builds, I'd be happy as a pig in s#?@...but that's just me! Quote Link to comment Share on other sites More sharing options...
minn_male42 Posted March 13, 2003 Share Posted March 13, 2003 i sell commercial/pro audio from the following lines.... quam, atlas sound, altec-lansing, jbl pro, electrovoice, soundtube, bogen, toa, peavey, qsc, crown, middle atlantic, telex, shure, akg, audio-technica, proco, phoneix gold, switchcraft, neutrik, belden, commscope, eastman, fluke, b&k precision, velleman, wiha, xcelite, klein tools, and many others.... as you can see from the list, i also sell alot of other electronic equipment and quality tools.... Quote Link to comment Share on other sites More sharing options...
Marvel Posted March 13, 2003 Share Posted March 13, 2003 kenratboy, Was going to post this from work, but we were working on the firewall today and things were up and down. I'll be showing my age here, but way back in the '60s either Popular Mechanics or Popular Electronics had an article on how to build a speaker system that used 16 five inch speakers (called the "Sweet Sixteen"). Each speaker didn't have to work much, because in total they moved a LOT of air. This is the principle of Steve Decker's line eight I believe. Many speakers working in unison means none of them are very stressed and work well (insert own opinion here). If you want to use multiple speakers, you just have to calculate the impedance values so you end up with what you want. You don't need a crossover. For example: four 8 ohm speakers can be connected to yield an 8 ohm load, a 32 ohm load, a 2 ohm load, or others. Resistance in series: R total=R1 + R2 + R3 + etc Resistance in parallel: 1 R total=----------------- 1 + 1 + 1 --- --- --- R1 R2 R3 Hope that is clear. Speakers are measured in ohms as impedance, which is a combination of resistance and reactance (inductive). Resistors have a fairly linear resistance to current flow. Coils (inductors, coils in speakers, etc.) have a reactive opposition to current flow, based on different things, but it varies also with frequency. This is why a speaker's impedance varies depending on the frequency of the signal being fed to it. Certain crossover filters present no load depending on the frequency. This can be fatal to an amplifier. Inductors (chokes), are measured in units of the term Henry. It is the measurement of Counter Electromotive Force, or cemf. School's out for the day. We could talk about litz wire (which is used in the inductors Al K uses for his crossover), and why it is better than solid wire (it's the skin effect). Marvel Quote Link to comment Share on other sites More sharing options...
kenratboy Posted March 14, 2003 Author Share Posted March 14, 2003 ---------------- On 3/13/2003 7:49:13 PM Marvel wrote: kenratboy, Was going to post this from work, but we were working on the firewall today and things were up and down. I'll be showing my age here, but way back in the '60s either Popular Mechanics or Popular Electronics had an article on how to build a speaker system that used 16 five inch speakers (called the "Sweet Sixteen"). Each speaker didn't have to work much, because in total they moved a LOT of air. This is the principle of Steve Decker's line eight I believe. Many speakers working in unison means none of them are very stressed and work well (insert own opinion here). If you want to use multiple speakers, you just have to calculate the impedance values so you end up with what you want. You don't need a crossover. For example: four 8 ohm speakers can be connected to yield an 8 ohm load, a 32 ohm load, a 2 ohm load, or others. Resistance in series: R total=R1 + R2 + R3 + etc Resistance in parallel: 1 R total=----------------- 1 + 1 + 1 --- --- --- R1 R2 R3 Hope that is clear. Speakers are measured in ohms as impedance, which is a combination of resistance and reactance (inductive). Resistors have a fairly linear resistance to current flow. Coils (inductors, coils in speakers, etc.) have a reactive opposition to current flow, based on different things, but it varies also with frequency. This is why a speaker's impedance varies depending on the frequency of the signal being fed to it. Certain crossover filters present no load depending on the frequency. This can be fatal to an amplifier. Inductors (chokes), are measured in units of the term Henry. It is the measurement of Counter Electromotive Force, or cemf. School's out for the day. We could talk about litz wire (which is used in the inductors Al K uses for his crossover), and why it is better than solid wire (it's the skin effect). Marvel ---------------- So you are saying if I hooked up 8, 8 ohm speakers in a series, they would still give a 8 ohm load???!!! And, like I thought, if you hooked them up in parallel, they would yeald 4, 2, 1, .5 ohms? If thats true (about impedance in a series) that could be fun to play with. Quote Link to comment Share on other sites More sharing options...
Marvel Posted March 14, 2003 Share Posted March 14, 2003 Follow through a step at a time: Four 8 ohm speakers in series = 32 ohms Do that again and you have another set at 32 ohms. Look at each set as one speaker now, 32 ohms each. Put those two in parallel and you have one speaker of 16 ohms. If you had four sets @ 32 ohms and put them in parallel, you would have an 8 ohm speaker array, holding 16 speakers. I could send you a drawing. Getting all in phase would be fun though. Marvel Quote Link to comment Share on other sites More sharing options...
kenratboy Posted March 14, 2003 Author Share Posted March 14, 2003 ---------------- On 3/14/2003 9:43:20 PM Marvel wrote: Follow through a step at a time: Four 8 ohm speakers in series = 32 ohms Do that again and you have another set at 32 ohms. Look at each set as one speaker now, 32 ohms each. Put those two in parallel and you have one speaker of 16 ohms. If you had four sets @ 32 ohms and put them in parallel, you would have an 8 ohm speaker array, holding 16 speakers. I could send you a drawing. Getting all in phase would be fun though. Marvel ---------------- Jeez, the impedance actually goes up (bigger #)? - I see EXACTLY what you are saying, but I didn't think it worked like that. Electricity is wierd . I understand now. Thanks!!! Quote Link to comment Share on other sites More sharing options...
Marvel Posted March 15, 2003 Share Posted March 15, 2003 kenratboy, Attached is a pdf with a short explanation and a graphic. It's easier to see when drawn out. It really only gets weird when you start adding values that are way different, like three 16 ohm speakers and five 8 ohm. Figuring that out would be more of a challenge. Having all the same values makes it much easier. If you follow through and do this, let us know how it works out. Cutting the front baffle would sure get tedious. Marvel speaker array.pdf Quote Link to comment Share on other sites More sharing options...
jt1stcav Posted March 15, 2003 Share Posted March 15, 2003 kenratboy...do you really want to go through all this headache? Why would you want a Bose-like array of puny drivers (is it a challenge) when you could put your talents to much better use by designing and building a true horn-loaded loudspeaker? That is a worthy challenge, IMO. Oh well, better mind my own business. Who am I to tell you what to do. Quote Link to comment Share on other sites More sharing options...
kenratboy Posted March 15, 2003 Author Share Posted March 15, 2003 ---------------- On 3/15/2003 1:20:00 PM jt1stcav wrote: kenratboy...do you really want to go through all this headache? Why would you want a Bose-like array of puny drivers (is it a challenge) when you could put your talents to much better use by designing and building a true horn-loaded loudspeaker? That is a worthy challenge, IMO. Oh well, better mind my own business. Who am I to tell you what to do. ---------------- No, I will not do it, just got interested in how the system worked. Just curious. I still want to make a horn subwoofer. Quote Link to comment Share on other sites More sharing options...
jt1stcav Posted March 15, 2003 Share Posted March 15, 2003 ---------------- On 3/15/2003 1:56:12 PM kenratboy wrote: No, I will not do it, just got interested in how the system worked. Just curious. I still want to make a horn subwoofer. ---------------- Now that's more like it...LOL! If you can successfully build a powerful horn-loaded subwoofer to go down to a clean 20Hz (or even lower), then I want to be the first to buy one from you (at a discount for hounding you all this time, natch!) Quote Link to comment Share on other sites More sharing options...
artto Posted March 15, 2003 Share Posted March 15, 2003 Ah, I see another unsolicited, first comment slander from EAR against me. EAR, you're not even creative or witty enough to come up with your own "line"! So now all you can do is turn the "nancyboy" thing on me?.........LMFAO I'll go on record right now.....I said it FIRST. Second, Third, etc, etc. Took you a while to figure out that you couldn't do better, so now you copy Arttie! LMFAO And if you don't watch it, I'll send you up into the mountains where you can pick up my previous "post in writing" (this time on a stone slate), at which time I will promptly break it over your A**. That, after all, is where your brains are at. I know. Because I put them there. Yes, its true EAR. Sorry. My Mistake. But at this time, I certainly have no intention of correcting it. Furthermore, both you & your old man shall remain nancyboys forever. Have a nice day. GOD Quote Link to comment Share on other sites More sharing options...
TheEAR Posted March 15, 2003 Share Posted March 15, 2003 Arttie, Silence you beer belly,next time you stand next to your Heritage speakers at least have the guts to post a full pic. All your brain farts amount to nothing constructive,you tap yourself on the shoulder for a job well done.Give yourself another tap for using the word NANCYBOY Quote Link to comment Share on other sites More sharing options...
lubbie Posted April 2, 2003 Share Posted April 2, 2003 FYI. Bose 901's are all 9*.8 ohm speakers wired in series. They use the active equalizer for matching the drivers to the cabinets. Each active crossover is special to the series, although they all show simular results on the scope. It is posible to use the 901 without the active eq if you have a plain eq and configure it in a V (boost the base and the treble) to about 12-15db. Bose 801's are the same but have lost the one front firing driver. And they flip the speaker around so all 8 drivers face the listener. The 801's also use the active eq, but its almost identicle to the 901. good luck Quote Link to comment Share on other sites More sharing options...
DTLongo Posted April 2, 2003 Share Posted April 2, 2003 I recall from Bose literature and other reviews from many years ago that the 901 speaker drivers are specially designed with a heavy magnet and "elliptical" voice coil wire, and that each driver has an impedance of around 1 ohm. Nine drivers in series in each enclosure = ca. 8 ohms. The drivers are solid and heavy little fellas. The 901 has no crossover, the outboard equalizer is required, which makes the speakers somewhat inconvenient to hook up. Bose doesn't publish the equalizer or speaker specs. Without the equalizer the speakers have no low bass or treble. With it, they have honest bass down to ca. 35 hz. and decent treble. Like other Bose products they have been hyped and overmarketed to the nines, though not so much nowadays as Bose has pushed its other product lines especially home theater systems. Unlike other Bose products, the 901 Series VI speakers are not grotesquely overpriced. They are actually rather good sounding, though purists and Bose-bashers, of course, vehemently disagree. Still, there's only so much a 4" driver can do, however grouped and equalized. Nonetheless, my 901 VI's are fairly efficient and can play fairly loudly. I have had them since around 1988 and have really enjoyed them. On the other hand, my new Klipschorns, ordered six months ago, have just arrived at my dealer's and are due to be delivered in a couple of days! Fulfillment at the age of 60 of my life-long speaker dream. I'm looking forward to THOSE babies. Quote Link to comment Share on other sites More sharing options...
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