Lostinozz Posted October 10, 2006 Share Posted October 10, 2006 I'm in the process of building a pair of speaker cabinets.[sn] I have several drivers to choose from for the midrange and the tweeter horns. My question is; what would the difference be, if any, in using 8 Ohm or 16 Ohm drivers of the same species, other than crossover considerations? I understand there would be a difference in woofers of different ratings but I'm not sure about the others. I've searched the Forum and can't find anything posted although I'm sure this has been covered in the past. Any information you can give me will be more information than I have now, heck, I may even go over to the "Ask Clarence" thread and see what words of wisdom he can bestow on me![] Thanks, Craig Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted October 10, 2006 Share Posted October 10, 2006 simple answer, less ohms means less resistance, which gives more power out of amp. Klipsch uses mostly 4ohm drivers to gain efficiency. If you had choice between 8 or 16, I'd tend to go for the 8's. M Quote Link to comment Share on other sites More sharing options...
Duke Spinner Posted October 10, 2006 Share Posted October 10, 2006 16 ohm drivers, are a Vestige of early tube equipment, in which it was desireable to keep current draw low Quote Link to comment Share on other sites More sharing options...
BiggerIsBetter Posted October 10, 2006 Share Posted October 10, 2006 The decision may also affect your level matching, i.e. if the mids and high are much more efficient the the low end driver, using a 16 ohm driver would be one way to close the gap. Quote Link to comment Share on other sites More sharing options...
Guest " " Posted October 10, 2006 Share Posted October 10, 2006 Higher impedance will result in less distortion. There are folks who use autoformers for increasing the impedance of drivers with the goal of attaining lower distortion. The zero autoformer is one such device, cost is about 500 bucks per pair. There are a few sites that have reviewed increasing impedance and how it effect distortion. Google zero autoformer. While it is true that lower impedance will result in the amp being able to produce more watts, the amp will also run hotter. As a point of intrest, in the heritage line of crossover network, we start out with a 16 ohm mid driver (which actually measures 11-14 ohms) and change the taps on the crossover's autoformer to reduce the drivers level by increasing the apparent impedance. tap 4 = 3b drop = 2x impedance tap 3 = 6b drop = 4x impedance tap 2 = 9b drop = 8x impedance tap 1 = 12b drop = 16x impedance Quote Link to comment Share on other sites More sharing options...
Lostinozz Posted October 10, 2006 Author Share Posted October 10, 2006 The reason I asked was to determine which drivers I should use in the Altec 288's that will be attached to Altec 803B 8 cell horns or possibly 1005B 10 cell horns (Ihaven't decided yet). These speakers will be used for my detached shop where I have plenty of room for the LARGE cabinets required to fit the horns in. I have a variety of large format drivers with diaphragms running from 4, 8, 16, 24 Ohm. I will be pushing these with a Krell KSA100 amp I've owned for 25 years. The Krell folks said it should have no trouble pushing the 4 total Stephens 103LX2 woofers I have for the double base bins, regardless if I run them in paralell or series. They said a 2 Ohm load wouldn't hurt them. For tweeters I could run either JBL bullets (8 Ohm) or Slots (8 or 16 Ohm). Any suggestions? Before someone states the obvious, yes these will be big with absolutely NO WAF, but like I said, these are for my shop and for letting my closest neighbor (1/4 mile away)enjoy them too.[6] They'll also help bring a little music to outdoor BBQ's. 1 Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted October 10, 2006 Share Posted October 10, 2006 The decision may also affect your level matching, i.e. if the mids and high are much more efficient the the low end driver, using a 16 ohm driver would be one way to close the gap. Isn't it usually the other way around, with the mid and high horns being much more efficient that the low section? Quote Link to comment Share on other sites More sharing options...
Lostinozz Posted October 11, 2006 Author Share Posted October 11, 2006 Just a little bump to bring this back to the top. Soooo,how about it, which Ohm driver would you use for the mid horn and tweeter? Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted October 11, 2006 Share Posted October 11, 2006 Craig, I don't think there is any difference in performace between an 8 and an 16 Ohm driver. Power is simply voltage time current. The ratio of this is the impedance. This is simple ohms law. Power = E x I and Zo = E / I. What counts is that the network you use is designed to properly match into the impedance of the driver you choose. If you use a transformer to set the level and have a proper swamping resistor ahead of the transformer you can use either impedance driver by just moving the tap settings. AL K. Quote Link to comment Share on other sites More sharing options...
DrWho Posted October 11, 2006 Share Posted October 11, 2006 It depends on the efficiency of each component of the speaker. You'll want to use higher impedance for more efficient devices (squakers / tweeters) and lower impedance for less efficient devices (woofers). If you do it right, you can end up with a crossover that doesn't need to employ any attenuation to match efficiencies - which results in a simpler design, which often sounds better too. Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted October 11, 2006 Share Posted October 11, 2006 It depends on the efficiency of each component of the speaker. You'll want to use higher impedance for more efficient devices (squakers / tweeters) and lower impedance for less efficient devices (woofers). If you do it right, you can end up with a crossover that doesn't need to employ any attenuation to match efficiencies - which results in a simpler design, which often sounds better too. yeah, that's what I was trying to say... Quote Link to comment Share on other sites More sharing options...
Lostinozz Posted October 11, 2006 Author Share Posted October 11, 2006 AlK, DrWho, and Coulter, Thank you for the information. That confirms what I have gleaned from bits and pieces of past posts in the Forum. I just wasn't positive that my conclusion was correct. Usually I'm about 180 out. When I get home I'll work on the cabinets (something I'm capable of). When I'm finished I may try to build some crossovers but will more than likely leave that up to one of the experts here on the forum. I would have no problem assembling crossovers of someone else's design but after studying lots of the information that's available, I realize designing them may be a bit over my head. Quote Link to comment Share on other sites More sharing options...
D-MAN Posted October 13, 2006 Share Posted October 13, 2006 16 Ohm drivers are typically used in pairs, wired parallel, resulting in a nominal 8 Ohms, making everything (amp/crossover considerations) relatively easy and painless. DM Quote Link to comment Share on other sites More sharing options...
Guest " " Posted October 14, 2006 Share Posted October 14, 2006 On a single driver loaded amp, the amps dampening factor is different at 8 ohms than at 16 ohms. The amps dampening factor is calculated by deviding the speaker load by the amps output impedance. If you increase the speaker load, the dampening factor increases. In years gone by, SS amps with higher dampening factors where more attractive than amps with lower ones. Quote Link to comment Share on other sites More sharing options...
Ray_pierrewit Posted February 22, 2021 Share Posted February 22, 2021 I apologize for resuscitating such an old thread, but I've posed my question elsewhere and haven't had any answers. Can I substitute the 8ohm EV 1823M with 16ohm A-55-G in my Electro Voice Sentry IV-B without modifying the crossover? Here is a schematic if it can be helpful. Quote Link to comment Share on other sites More sharing options...
HiFi Heaven Posted February 22, 2021 Share Posted February 22, 2021 Damping factor only applies to amplifier control of a woofer. Once a cap blocks DC to a midrange, DF is irrelevant. Parallel 8 ohms will lose 3dB but maintain crossover. Give it a try! Quote Link to comment Share on other sites More sharing options...
OO1 Posted February 22, 2021 Share Posted February 22, 2021 you certainly can , but the 16 ohms driver will draw 2x less current from the amplifier versus the original 8oms driver ---which means the midrange may not sound as loud by 3db -- Quote Link to comment Share on other sites More sharing options...
Ray_pierrewit Posted February 22, 2021 Share Posted February 22, 2021 Oops, my bad. The A55G is 12ohm rather than 16. In any case, I went ahead and installed them but haven't had time to listen just yet. Quote Link to comment Share on other sites More sharing options...
Ray_pierrewit Posted February 22, 2021 Share Posted February 22, 2021 A fellow over on the audio asylum high efficiency forum suggest I wire a 24 ohm resistor in parrallel to bring the 12 ohm driver down to 8 ohm. Shouldn't bee too hard a fix, I believe. Quote Link to comment Share on other sites More sharing options...
Ray_pierrewit Posted February 22, 2021 Share Posted February 22, 2021 A quick mockup I drew just to be clear, as I don't have much working electronics knowledge, according to the gentleman's calculation over on audio asylum. Does this look correct? Quote Link to comment Share on other sites More sharing options...
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