Ar9Jim 6,513 Posted February 21, 2015 Posted February 21, 2015 I have been reading in the old topics and also in current post about different ways people bi-amp their systems as I prepare for a project coming up.I'm armed with some practical knowledge from experimenting with bi-amping Carver M400s in the 80s and reading magazines back then.Please forgive me if this topic is the SOS to the more senior members.I have looked through a lot of old post.Rich and Dom have posted a great deal of info on this subject that seems to confirm my memory of my 1980s system and the many ways it was configured.Question #1.Why do people who are bi-amping crossing the signals of their amps outputs stating that they use the output of one amp for woofers on the left channel and upper end on the right channel?In this case the input must be a full range signal. Question #2.With speakers that are factory bi-ampable with 4 binding post many people feed full range signals to all 4 post and let the passive crossovers turn the rest into heat and what ever else comes with dissipating the unused signal and amp power.Will either of these methods while technically bi-amped (2 amps) ever show the full benefits of bi-amping? In both cases the amps are being fed full range signals.Bi-amping is probably more about the signal being input to an amp than either of these two seemingly common set ups take advantage of. If your speakers are factory bi-ampable then its easy to find out the crossover point to the woofers on line on in your manual.Get a 2 way active crossover set up for the point you need.Leave the passive crossovers in your speakers alone,you don't need to do anything with them to bi-amp other than removing the jumpers from the binding post.Try it. 1
danowood 2,167 Posted February 21, 2015 Posted February 21, 2015 It is to my understanding by senior members here, the true advantage of bi-amping comes with the use of active crossovers and by disconnecting the passives altogether. For those that don't have the active crossovers then there is a sense of some accomplishment (but not full advantage) of separating the crossovers and running bi-amped. The advantage is load reduction with bi-amping IMO. 2
RodH 4,866 Posted February 21, 2015 Posted February 21, 2015 True, passive bi-amping does not convey all the benefits of active, but the increase in available headroom is still worthwhile. 3
fill35U 1,846 Posted February 21, 2015 Posted February 21, 2015 Please forgive me if this topic is the SOS to the more senior members.I have looked through a lot of old post. No worries, Jim! Keeps us sharp, and gives us something to discuss! Question #1.Why do people who are bi-amping crossing the signals of their amps outputs stating that they use the output of one amp for woofers on the left channel and upper end on the right channel?In this case the input must be a full range signal. Check out yet ANOTHER THREAD that might help you understand the "diagonal biamping" setups more. Question #2.With speakers that are factory bi-ampable with 4 binding post many people feed full range signals to all 4 post and let the passive crossovers turn the rest into heat and what ever else comes with dissipating the unused signal and amp power.Will either of these methods while technically bi-amped (2 amps) ever show the full benefits of bi-amping? Crossovers don't necessarily dissipate heat from the power signal that isn't of interest. An ideal capacitor or inductor would dissipate no heat at all, and usually manufacturers try to approach those ideals since low heat generally means longer life and friendlier to use. Sometimes the resistance of an inductor is deliberate or used to advantage. Even shunt-connected reactive crossover components can't pass too much current, or the amplifier will be unhappy. That said, there are often attenuating resistances and notch filters that *do* waste heat, and those can be reduced or eliminated by active crossovers. Passive crossovers can affect the load the amplifier sees, for worse or for better. And passive components can block harmful outputs from an amp, so they can help protect drivers. Passive biamping doesn't help the *voltage* headroom directly, but if the load is split between amps then their power supplies won't sag as much as a single heavily loaded amp would. It still spreads the current demands and IR and heat losses between amps, and reduces current-dependent distortion. In both cases the amps are being fed full range signals.Bi-amping is probably more about the signal being input to an amp than either of these two seemingly common set ups take advantage of. I don't follow you there, Jim? *Active* biamping sends different signals than passive biamping, of course. If your speakers are factory bi-ampable then its easy to find out the crossover point to the woofers on line on in your manual.Get a 2 way active crossover set up for the point you need.Leave the passive crossovers in your speakers alone,you don't need to do anything with them to bi-amp other than removing the jumpers from the binding post.Try it. If you leave the passive crossovers in place and connect the same way as for passive biamping, then the passive crossovers will *still* affect the signals the drivers see. Yes, the active crossover will be working, but so will the passives. The combined effect may not be optimum. Speakers are designed so the output of each driver is carefully controlled, especially in the tricky crossover region. That region may extend an octave or more on either side of the crossover frequency. Dropoff or peaking of sound from the driver, phasing, and directionality might not work out as well. The Pro approach is to use 24dB/octave (4th order) LR crossovers to get out of the crossover region as quickly as possible, which allows for greater driver bandwidth and power utilization and ease of positioning. But every speaker is different, so leaving passives in place might significantly change the sound. 3
fill35U 1,846 Posted February 21, 2015 Posted February 21, 2015 And a reminder that if you like to crank up the volume, or *have* to because of inefficient speakers, multiamping reduces the dynamic range of the signal each amp sees. If you take advantage of the headroom you've gained and use it, you'll be putting a lot more average power through your amps and speakers. Be careful! 2
Ar9Jim 6,513 Posted February 21, 2015 Author Posted February 21, 2015 Thanks for the response.So your saying that the 4 binding post are supposed to be fed the full range signal even when the jumpers are removed.Would a passive crossover have less effect on a signal if the frequency it is designed to filter is removed by an active crossover upstream?Seems it would have closer to a free pass through? 1
RodH 4,866 Posted February 21, 2015 Posted February 21, 2015 This will likely get me in some hot water, but here it goes.. When a speaker manufacturer produces a speaker with a built in passive crossover, they (hopefully) try to get the best response from the cabinet/driver combination that they are utilizing. Simply removing the internal passive and going with an active frequency crossover, cutting the signal at the proper point and removing power robbing components from the signal path seems good - but: shelving, notch filtering and any other response correcting processes from the original crossover design are eliminated. Now what? To get it right - in YOUR space with YOUR other components, you need to use a microphone/analysis process to make things right. Simply going active without the additional step can be counterproductive. I'm looking very hard at getting the MiniDSP to give it another try. YMMV. 6
Ar9Jim 6,513 Posted February 21, 2015 Author Posted February 21, 2015 I had good results with the active xo matched to the passive xo point.Even though the speakers were fed through the binding post with passive xo still stock and in place doing their job with the 3 upper range drivers and lower range drivers as stock.The bi-amp is only a 2 way split so the passive xo has to be there on more than a 2 way speaker.The guy that talked me into the bi-amp thing 30 yrs ago was very smart and when I mentioned that the signal still goes through the passive xo his reply was "so what,that cap and coil can't remove something thats not there".And it worked great so good that it stayed that way until I sold it.Question is does that passive xo really care if part of the dynamic range is removed by an active xo first?Is there a technical reason for a passive xo to be affected by having less range input?Thanks again I'm learning and wondering if my success was luck or what? 1
fill35U 1,846 Posted February 22, 2015 Posted February 22, 2015 The bi-amp is only a 2 way split so the passive xo has to be there on more than a 2 way speaker. FWIW there's triamping, and many of the popular active XO's are configurable as 2- or 3-way. The guy that talked me into the bi-amp thing 30 yrs ago was very smart and when I mentioned that the signal still goes through the passive xo his reply was "so what,that cap and coil can't remove something thats not there". Does the active crossover really leave nothing there? Here are the extreme cases: if the active passes everything with no effect, the passive sees the full signal, this section of the speaker is acting exactly as designed, but there's no point to having the active XO. If the active has a cutoff frequency or slope such that the output to the passive is nil, then... the active XO has a different cutoff frequency or slope than the speaker was designed with. If the active and passive XO have the same cutoff frequency and slope, then using them both will mean their effects are *additive*. Again different from how the speaker was designed. Anything else will fall somewhere between these cases. The overall effect may be better, worse, different, or unnoticeable... And it worked great so good that it stayed that way until I sold it.Question is does that passive xo really care if part of the dynamic range is removed by an active xo first? Is there a technical reason for a passive xo to be affected by having less range input? If you take advantage of the headroom you gain and *turn up the volume* past where you were limited before, then the amps and speakers, including passive XO's that are still hooked up, will see increased stress. The design, quality, and age of the passive XO components will determine if they fail. Stress increases distortion and other bad effects for pretty much everything, but it might still sound better for other reasons. Thanks again I'm learning and wondering if my success was luck or what? You're welcome! I know my answers are vague, but I'm not an expert and it's tough to make predictions on overall improvements without an awful lot of data or experience. I hope it helps! 3
Ar9Jim 6,513 Posted February 22, 2015 Author Posted February 22, 2015 I would beg to argue that it is perfectly fine to bi-amp using a 2 way active crossover set at the factory woofer xo point and feed the low pass to one amp and the high pass to another amp feeding the upper end and woofer binding post using the factory passives to process from that point.I have reason to believe that the passives may actually work better when processing a reduced bandwidth signal.Amps work better that way with reduced IM distortion and thats measurable.The Kappa 9 (Gene and now Kevin) would be perfect.Big powerful hungry speakers.Factory xo point to the woofers of 80 hz.Use a simple 2 way active with a 80 hz chip or program .If you feed an 80 hz and down signal into a M1.0 and run the 4 -12s with it it will bring those woofers under tight control.With the limited bandwidth the amp will perform awesome.Same with the upper end.Take away the power hungry 80 hz low pass signal from the upper end input and the amp running the reduced bandwidth signal sounds great and super clean with an improvement for sure.Let the factory passives take it from there for the rest of the upper end processing.If you happen to (overdrive) clip the bass amp it doesn't smoke your tweeters, nice benefit with vintage or expensive speakers.The high end auto sound guys have been using combinations of active xo and passives a long time.Guys with ribbons would benefit huge from an amp running them that wasn't responsible for bass.There must be others out there that have bi-amped multi-way speakers using a combination of active and passive XOs.As long as you matched the woofer xo point,what were your results? 1
Ar9Jim 6,513 Posted February 22, 2015 Author Posted February 22, 2015 In Gene's case he is blessed with some big carver mono blocks but for the guy with a couple carver conventional amps around the house and bi-ampable speakers your really close to something fun. 1
LVMAN777 352 Posted March 7, 2015 Posted March 7, 2015 I am thinking about trying bi-amping on a set of Carver Platinum's with 2 M1.5t's My plan is to passive filter the M1.5t's inputs coming from my Carver C1 I think the crossover frequency should be 200 hz. Any suggestions for a two way line level passive crossover unit? 1
LVMAN777 352 Posted March 7, 2015 Posted March 7, 2015 EXACTLY what I am looking for (@ 200hz) AND......."The Price is Right!"
niccolosito 328 Posted March 7, 2015 Posted March 7, 2015 I would beg to argue that it is perfectly fine to bi-amp using a 2 way active crossover set at the factory woofer xo point and feed the low pass to one amp and the high pass to another amp feeding the upper end and woofer binding post using the factory passives to process from that point.I have reason to believe that the passives may actually work better when processing a reduced bandwidth signal.Amps work better that way with reduced IM distortion and thats measurable.The Kappa 9 (Gene and now Kevin) would be perfect.Big powerful hungry speakers.Factory xo point to the woofers of 80 hz.Use a simple 2 way active with a 80 hz chip or program .If you feed an 80 hz and down signal into a M1.0 and run the 4 -12s with it it will bring those woofers under tight control.With the limited bandwidth the amp will perform awesome.Same with the upper end.Take away the power hungry 80 hz low pass signal from the upper end input and the amp running the reduced bandwidth signal sounds great and super clean with an improvement for sure.Let the factory passives take it from there for the rest of the upper end processing.If you happen to (overdrive) clip the bass amp it doesn't smoke your tweeters, nice benefit with vintage or expensive speakers.The high end auto sound guys have been using combinations of active xo and passives a long time.Guys with ribbons would benefit huge from an amp running them that wasn't responsible for bass.There must be others out there that have bi-amped multi-way speakers using a combination of active and passive XOs.As long as you matched the woofer xo point,what were your results? +1 here, AR9Jim. Except that I set my XO point at 200hz, a bit higher than stock XO point which I presume is good for the ribbons. I'm running my AL-III+/SF 200x5 bi-amped with a Rane AC22B with the passive XO for the HF intact. In addition to what AR9Jim is saying, this arrangement gives one the choice of using SH only on the mid- and high frequencies, thus avoiding the apparent boost of low frequencies esp. with the early C-4000. Both these ideas I remember picking up from the late BillD's comments on biamping. He didn't really elaborate on them but what I read was enough for me. I proceeded with the "partial" biamping which involved nothing but clipping and resoldering the woofer wire directly to the binding post. Anyone can put together a twitter and a woofer in a box and come up with a speaker but design a proper crossover? Not easy. So why discard an XO designed by Bob Carver? 1
zumbini 6,147 Posted March 7, 2015 Posted March 7, 2015 I would beg to argue that it is perfectly fine to bi-amp using a 2 way active crossover set at the factory woofer xo point and feed the low pass to one amp and the high pass to another amp feeding the upper end and woofer binding post using the factory passives to process from that point.I have reason to believe that the passives may actually work better when processing a reduced bandwidth signal.Amps work better that way with reduced IM distortion and thats measurable.The Kappa 9 (Gene and now Kevin) would be perfect.Big powerful hungry speakers.Factory xo point to the woofers of 80 hz.Use a simple 2 way active with a 80 hz chip or program .If you feed an 80 hz and down signal into a M1.0 and run the 4 -12s with it it will bring those woofers under tight control.With the limited bandwidth the amp will perform awesome.Same with the upper end.Take away the power hungry 80 hz low pass signal from the upper end input and the amp running the reduced bandwidth signal sounds great and super clean with an improvement for sure.Let the factory passives take it from there for the rest of the upper end processing.If you happen to (overdrive) clip the bass amp it doesn't smoke your tweeters, nice benefit with vintage or expensive speakers.The high end auto sound guys have been using combinations of active xo and passives a long time.Guys with ribbons would benefit huge from an amp running them that wasn't responsible for bass.There must be others out there that have bi-amped multi-way speakers using a combination of active and passive XOs.As long as you matched the woofer xo point,what were your results? +1 here, AR9Jim. Except that I set my XO point at 200hz, a bit higher than stock XO point which I presume is good for the ribbons. I'm running my AL-III+/SF 200x5 bi-amped with a Rane AC22B with the passive XO for the HF intact. In addition to what AR9Jim is saying, this arrangement gives one the choice of using SH only on the mid- and high frequencies, thus avoiding the apparent boost of low frequencies esp. with the early C-4000. Both these ideas I remember picking up from the late BillD's comments on biamping. He didn't really elaborate on them but what I read was enough for me. I proceeded with the "partial" biamping which involved nothing but clipping and resoldering the woofer wire directly to the binding post. Anyone can put together a twitter and a woofer in a box and come up with a speaker but design a proper crossover? Not easy. So why discard an XO designed by Bob Carver? I've done it both ways, but currently have the passives bypassed as my Legacy's are straight high/low pass. If I had Amazings I'd be tempted to go quasi-electronic (keep the passives to avoid recreating the notch filters). Note that Bob changed his crossover designs constantly so he must have felt they could be improved upon. 2
TNRabbit 371 Posted March 7, 2015 Posted March 7, 2015 http://thecarversite.com/yetanotherforum/default.aspx?g=posts&t=3174 You only need to hear the ribbons once without the passive crossovers holding them back, and it will never be the same again... 1
kve777 6,888 Posted March 7, 2015 Posted March 7, 2015 When you get to this level of fine tuning, measurements mean less and personal taste reigns supreme. The kind of music, room and hearing damage to the lister become critical. I personally need about 10 systems. One for TV/Movies, one for Pink Floyd, another for Nine Inch Nails, yet another for Nirvana. Then there's the women- Tori Amos, Stevie Nicks, The Wilson sisters, Dusty Springfield... There is no end! 2
zumbini 6,147 Posted March 8, 2015 Posted March 8, 2015 When you get to this level of fine tuning, measurements mean less and personal taste reigns supreme. The kind of music, room and hearing damage to the lister become critical. I personally need about 10 systems. One for TV/Movies, one for Pink Floyd, another for Nine Inch Nails, yet another for Nirvana. Then there's the women- Tori Amos, Stevie Nicks, The Wilson sisters, Dusty Springfield... There is no end!You sir are VERY NEEDY! 1
Ar9Jim 6,513 Posted March 8, 2015 Author Posted March 8, 2015 Since I last post on this topic I have learned a lot and set up my bi-amp system yesterday.I am very happy with it and want to share.After a lot of reading and researching the active crossover options I decided against the pro units because of the issues with adapting to balanced connectors on most units and would rather keep the connections simple.I like the suggestion of an Audio Control Richter Scale 3 by Zumbini but it seemed like after his post they vanished from the planet.Found a series 1 but it has only 2 preset points so it wasn't an option.I was reluctant to buy a Mini dsp even though most of what I had read was positive.I thought here's a cheap A/D converter,processor and back to a D/A converter in the line level so all of its issues get amplified,I don't know?But on the other hand if the processing can be done in the digital domain its not likely to pick up hum or noise right?The background is black and quiet in digital normally.I mostly listen to digital sources these days so I guess another A/D to D/A conversion shouldn't bother me because I already bit that apple so to speak. I am using a C1 with the Mini DSP and (2) M1.0t Carvers.I am using AR90 4way speakers with the passive xovers in use.I made these speakers bi-ampable after reading old notes from AR engineers about how to do it and comparing the schematics with the AR9 that was factory set up for bi-amp.Ends up at the points I needed to separate (not bypass)the factory used spade lugs and it was mostly plug and play,like they prepared ahead for me,sweet! At the moment the set up in the mini in conservative having the low pass 1 octave above and the high pass 1 octave below the factory woofer xover point.I had issues at first with the mini but was helped by a post from Ben and Toymaker on CS.I will add to that post also.The mini is clean,quiet and super versatile.I will add to Ben's post because the advise in it from Toymaker kept me from throwing the mini in the snowbank so I could hit it with the lawn mower in the spring.All is well now.Sweet to adjust with a laptop in real time and see the change you heard. 3
hammytech 51 Posted March 9, 2015 Posted March 9, 2015 There is Bi-Amping, which is awesome, and recommended... and then there is Tri-Amping. Example. 2
zumbini 6,147 Posted March 9, 2015 Posted March 9, 2015 I'm using 4 amps to drive 3 frequency bands. Am I quad-amping or tri-amping?
Ar9Jim 6,513 Posted March 9, 2015 Author Posted March 9, 2015 That a nice high powered system Dom!Did you setup the sound when you and your brother worked at Cosmic lights?Quad-amp 3 way system sounds accurate?
TNRabbit 371 Posted March 9, 2015 Posted March 9, 2015 Assuming the subs share the same frequency range, you are tri-amping. 2
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