Coytee Posted March 15, 2010 Share Posted March 15, 2010 Congrats on your final assimilation to the dark side. As you see.... the process is not without its bumps and bruises however, total submission to the dark side has some golden nuggets to be found. Someday I would like to put some Jub bass bins in there and compare the sound. So, if anyone near me has a set they could loan me, drop me a note. I know it's a pain in the neck to move things, but would it be possible to take your top sections to the Jubilees rather than the larger Jubilee to your room? (I know it's better to hear in your place but we're not talking shoe boxes here!) [] 1 Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted March 15, 2010 Author Share Posted March 15, 2010 I guess moving the top section would certainly be easier. But I have found over the years that comparing system 'sound' when not in the same location is just not a good way to compare gear. To me, things sound way different in different rooms. I have quite a few treatments in my room and just that difference made my Khorns sound very different. Comparing bass bins in another space really isn't going to tell me much. OTOH, you right, they are slightly larger than a shoe box. [] As far as my passive vs. active transformation, I found more than just a few nuggets. There are pro and con points, but the good greatly outweighs the cost and a few other minor issues. Quote Link to comment Share on other sites More sharing options...
DrWho Posted March 15, 2010 Share Posted March 15, 2010 BTW, how do those curves look to you? It was the best I could achieve by messing around with the delay and/or phase function on the DCX. That's the beauty of measurements...not knowing the full context about the measurement makes it impossible to either validate or invalidate the relatively smooth curve you're showing. [] The way I look at frequency response curves, is that they should be used for identifying problems. Obviously the line isn't perfectly flat so the real question is whether or not those aberrations are due to the measurement technique or due to the actual speaker itself. I would just wait until something sounds out of place and then see if you can't find a way to use measurements to quantify what you're hearing. Considering what I think the polar response of your setup might be, it seems like things are a bit too flat if that's truly representative of the anechoic on-axis response. Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted March 15, 2010 Author Share Posted March 15, 2010 That's the beauty of measurements...not knowing the full context about the measurement makes it impossible to either validate or invalidate the relatively smooth curve you're showing. The way I look at frequency response curves, is that they should be used for identifying problems. Obviously the line isn't perfectly flat so the real question is whether or not those aberrations are due to the measurement technique or due to the actual speaker itself. I would just wait until something sounds out of place and then see if you can't find a way to use measurements to quantify what you're hearing. Considering what I think the polar response of your setup might be, it seems like things are a bit too flat if that's truly representative of the anechoic on-axis response. I understand. I do know last year, before heavily treating the room, it was nowhere near that flat. These plots also repesent the four eq points I put in. Two in the woofer to flatten out the hump, one near the lo-mid crossover point to boost the area where both drivers are droopy, and the fix to the 10kHz tweeter drop. I also closed down the IR window as you suggested in months past. I wish there was a simple way to measure the polar response....that the average guy could affort. Also, I think moving the tweeter to a location on top of the top hat, directly above the mid horn, helped. Maybe its just me. Cheers. Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted March 24, 2010 Author Share Posted March 24, 2010 DrWho, quick question. In one of your many replies you inferred that when you bridge a stereo amp you increase the distortion....or some such notion. Can you explain? For some reason that stuck with me and since I'm all out of active crossover questions I figured I'd hit this one. Quote Link to comment Share on other sites More sharing options...
Coytee Posted March 24, 2010 Share Posted March 24, 2010 The way I've come to view it in my mind... (very technical I might add so put on your glasses, grab your pipe and smoking jacket so you will look sophisticated while reading this) When you are bridging the amps, you have one channel working the sine wave 'above the line' and the other channel works the sine wave 'below the line' What happens "at" the line? ("no mans" land) You have a bit of amp confusion (distortion) as you hand the signal over to one channel or the other. Anytime you change hands you might be messing up the signal a little bit. Contrast that to not bridging it and each channel is controlling the sine wave both, above and below the line so you have total control of the sine wave by the amp at all times with no handing off issues. I don't know the real techncial jargon but that's how I viewed it in my head. If the above is acceptable to Who and his bretheren engineers, maybe they will start to realize that us mortals, sometimes need simple illustrations. [] Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted March 24, 2010 Author Share Posted March 24, 2010 Now that is an explanation I can understand. Thank you. Quote Link to comment Share on other sites More sharing options...
DrWho Posted March 24, 2010 Share Posted March 24, 2010 Well you're really close Richard....[][] When you bridge an amp, both sides of the amplifier are amplifying into both the positive and negative portion of the wave. There is no hand off taking place. However, one of the channels has the polarity inverted so that when the non-inverted one swings positive, the inverted one swings negative. The speaker is then connected to the positive jack from each channel: speaker + goes to the non-inverted amplifier +, and speaker - goes to the inverted amplifier +. If you have an unbridged amplifier with +/-100V rails, then the maximum voltage that can be delivered to the speaker will be 100V since the negative terminal of the speaker is connected to ground. When you bridge, the one channel goes to +100V while the other channel swings to -100V...since the speaker negative is connected to both outputs, now the speaker sees 200V across its terminals (which is +6dB SPL). When the music signal goes negative, then the first channel will go to -100 while the second channel swings to +100... So with that in mind, it should be mentioned that almost all amplifiers tend to have a little difficulty at the zero crossing. When you bridge, you just double the magnitude of this discontinuity. The other issue is that the damping factor gets cut in half, and the noise floor gets higher. Quote Link to comment Share on other sites More sharing options...
Rudy81 Posted March 24, 2010 Author Share Posted March 24, 2010 So with that in mind, it should be mentioned that almost all amplifiers tend to have a little difficulty at the zero crossing. When you bridge, you just double the magnitude of this discontinuity. The other issue is that the damping factor gets cut in half, and the noise floor gets higher. The above is the critical part for our application. What I don't need is a damping factor cut in half and a higher noise floor! Many thanks for the explanation. Quote Link to comment Share on other sites More sharing options...
Coytee Posted March 25, 2010 Share Posted March 25, 2010 Well you're really close Richard.... When you bridge an amp, both sides of the amplifier are amplifying into both the positive and negative portion of the wave. There is no hand off taking place. However, one of the channels has the polarity inverted so that when the non-inverted one swings positive, the inverted one swings negative. The speaker is then connected to the positive jack from each channel: speaker + goes to the non-inverted amplifier +, and speaker - goes to the inverted amplifier +. If you have an unbridged amplifier with +/-100V rails, then the maximum voltage that can be delivered to the speaker will be 100V since the negative terminal of the speaker is connected to ground. When you bridge, the one channel goes to +100V while the other channel swings to -100V...since the speaker negative is connected to both outputs, now the speaker sees 200V across its terminals (which is +6dB SPL). When the music signal goes negative, then the first channel will go to -100 while the second channel swings to +100... So with that in mind, it should be mentioned that almost all amplifiers tend to have a little difficulty at the zero crossing. When you bridge, you just double the magnitude of this discontinuity. The other issue is that the damping factor gets cut in half, and the noise floor gets higher. If you would have read what I said with your pipe and smoking jacket on, you would have come away with this exact understanding. Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted March 25, 2010 Share Posted March 25, 2010 100V since the negative terminal of the speaker is connected to ground. When you bridge, the one channel goes to +100V while the other channel swings to -100V...since the speaker negative is connected to both outputs, now the speaker sees 200V across its terminals (which is +6dB SPL). When the music signal goes negative, then the first channel will go to -100 while the second channel swings to +100... Good god, man. According to Mr. Ohm, it's V squared over the impedance. With a 12 Volt swing across 8 ohms, you get 18 Watts of power delivered to a horn and that's pretty frikkin' loud. I"m into Milliwatts at normal 80 db average listening, so I don't get why someone would want to have a 200 Volt, or even a 100 Volt swing!! I'm pretty sure a 50Volt supply rail or less is standard so 100 V from bridging is still an insane amount of power for a horn at a peak of about 1 Kilowatt of power. You guys are nuts............after all, it's only a 30 AWG wire in the voice coil for gosh sakes. I used to be into 200 w/ch. amplifiers when I was 20 years old, but that's for a commercial system with twin 15" Altec woofers in 20 cu ft. boxes. I used to play gigs for 600 college kids at unreal loud levels with that in huge rooms at reception halls. Quote Link to comment Share on other sites More sharing options...
minermark Posted September 4, 2014 Share Posted September 4, 2014 Active for three weeks, the size of my Balls is slowly coming back since having my chit jumped by a neighbor (Street behind me four houses down). Well at this point i seem to have achieved the system iv always wanted, kind of a pizzer cannot crank it. All is not lost, this Neighbor BS just motivated me to look for real estate in Nevada just a little sooner. Good news! got the hanger my Bud and i have been bidding on. Stead Field Nevada. Partner and i agree, space for local bands ! 1 Quote Link to comment Share on other sites More sharing options...
djk Posted September 5, 2014 Share Posted September 5, 2014 ±161V (116V RMS) each channel in stereo, double the voltage for bridged mono. http://www.peaveycommercialaudio.com/media/pdf/9001_10-15-97.pdf Quote Link to comment Share on other sites More sharing options...
Deang Posted September 5, 2014 Share Posted September 5, 2014 I don't know about these days, but bridging used to sound terrible. Quote Link to comment Share on other sites More sharing options...
djk Posted September 5, 2014 Share Posted September 5, 2014 Depends on how it's bridged, the APT Model 1 sounded better in bridge mode than in stereo. The Ampzilla III and the Sumo Andromeda were designed as bridge amps as were the current Ampzilla 2000 designs. Quote Link to comment Share on other sites More sharing options...
Deang Posted September 6, 2014 Share Posted September 6, 2014 Damn, that's insane. Quote Link to comment Share on other sites More sharing options...
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