# bi amping ALL pro equipment



## xtinkshun

I am wondering what type of benefit if any bi-amping will give me. When I talked to the QSC rep. he highly recommended it for various reasons. Here is some background. The speakers I own are QSC 2150 I'll post some specs later. They have an option when wiring your speakers to select either Passive or Bi-amp. Apparently the internal crossover takes over from there. I am wondering what difference I would hear if I ran a Crown XLS 1500 in bridge passive (1050 W @ 8 ohm, 1550W @ 4 ohm). Does the crossover automatically run both my HF, & LF at 8 ohms or 4 ohms. As you can see from the specs below each operates at a different level. 



Here is a link to the 2150 specs, it did not appear as I formatted it. http://qsc.com/products/Loudspeakers/Dcs_Series/SC-2150/





Second question: Let's assume bi-amping would be beneficial. I'm not even sure how to do it. Is this correct? Would I wire one 4 pole Speakon cable with the +1 and -1 and use that for my HF and connect to output channel 1. Then wire my second 4 pole speakon cable with the +2 and -2 for my LF and connect that to output channel 2. Then wire them to my speakers bi-amp connections? If this is correct do I need a Y cable to connect both RCA ch 1 &2 outputs into the back of my AVR single input? And of course enter my amps setup and change to bi-amp mode. 

This would be a much cheaper option and take up less space than buying 3 more Crown XLS amps and running them bridged. ie 6 separate amps. I was also considering the X1000 for $99.00 If I could bi-amp like above that would be awesome. I could buy 3 instead of 6.


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## xtinkshun

*Bi-amp these?*

I am wondering what type of benefit if any bi-amping will give me. When I talked to the QSC rep. he highly recommended it for various reasons. Here is some background. The speakers I own are QSC 2150 I'll post some specs later. They have an option when wiring your speakers to select either Passive or Bi-amp. Apparently the internal crossover takes over from there. I am wondering what difference I would hear if I ran a Crown XLS 1500 in bridge passive (1050 W @ 8 ohm, 1550W @ 4 ohm). Does the crossover automatically run both my HF, & LF at 8 ohms or 4 ohms. As you can see from the specs below each operates at a different level. 

Here is a link to the 2150 specs, it did not appear as I formatted it. http://qsc.com/products/Loudspeakers...eries/SC-2150/

Second question: Let's assume bi-amping would be beneficial. I'm not even sure how to do it. Is this correct? Would I wire one 4 pole Speakon cable with the +1 and -1 and use that for my HF and connect to output channel 1. Then wire my second 4 pole speakon cable with the +2 and -2 for my LF and connect that to output channel 2. Then wire them to my speakers bi-amp connections? If this is correct do I need a Y cable to connect both RCA ch 1 &2 outputs into the back of my AVR single input? And of course enter my amps setup and change to bi-amp mode. 

This would be a much cheaper option and take up less space using 3 Crown XLS amps and running them bi-amped vs. buying 6 and running each bridged mono. Leaving my Crown XLS 1500 bridged and sending 1050 watts directly to 1 speakers or "BI- AMP" the speakers and send 300 watts to the HF and sending 525watts to the LF. According to the specs that should be sufficient. IF it is just bridged how is it distributing the power through the crossover. How much wattage and what OHM to my LF and HF ?


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## Wayne A. Pflughaupt

xtinkshun said:


> They have an option when wiring your speakers to select either Passive or Bi-amp. Apparently the internal crossover takes over from there.


Not exactly. I get the impression that you believe this speaker will be biamped the same way home speakers are. With home speakers, after taking out the jumper between the two sets of binding posts, two amplifiers are connected directly to the binding posts and the internal passive crossover still functions to divide the frequencies out to the drivers.

However, this is a professional speaker, and in pro audio “biamping” typically means an active system using an electronic crossover. The specs for your speaker show “Crossover Frequencies (biamp) 500 Hz active, 24 dB/octave to mid-high, 2200 passive.” Please note the word “active.” This tells me that the biamp switch bypasses the internal passive crossover between the woofers and the mid/high drivers, and is replaced by an electronic crossover set for 500 Hz with a 24 dB/octave slope. Each speaker will require two amplifier channels, one for the dual 15s and one for the mid/high drivers.

As to whether or not it will make a difference, that’s hard for me to say. The main benefit of an active system is greater sensitivity: Passive crossovers suck up a lot of power, so for a given input wattage an active system will play much louder than a passive system will. However, you don’t fully get this benefit with this QSC speaker because in biamp mode the mid/high section remains passively filtered.

Regards, 
Wayne


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## xtinkshun

I was with you all the way to the very end Wayne, Im not sure about your last sentence. What do you mean by.. _However, you don’t fully get this benefit with this QSC speaker because in biamp mode the mid/high section remains passively filtered._ Does this mean bi-amping them would be the same as bridged mono? Before we get too technical since I will not be buying 6 amps just to "TRY" the bi-amped. My intention was to use both channels on my Crown XLS amp to bi-amp each speaker. ie. ch. 1 to my HF and ch2. to my LF is that possible? If not, im done there. lol IF it it possible I don't mind a quick experiment. I have the wire and speakon cables as well as a Crown amp to test with. IF its possible was my above description for wiring correct or incorrect. 
Or would I need a piece of equipment between my amp and speaker, ie external crossover?

*the picture below does not belong to me*


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## xtinkshun

Would it be worth it to get extra bass from the dual 15's? They don't really put out bass like a 15" driver should. Some have said its because the crossover to the 15's are set so high. Would it make a difference if I bi-amped just for the LF?


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## gazoink

*Re: Bi-amp these?*



xtinkshun said:


> I am wondering what type of benefit if any bi-amping will give me. When I talked to the QSC rep. he highly recommended it for various reasons. Here is some background. The speakers I own are QSC 2150 I'll post some specs later. They have an option when wiring your speakers to select either Passive or Bi-amp. Apparently the internal crossover takes over from there. I am wondering what difference I would hear if I ran a Crown XLS 1500 in bridge passive (1050 W @ 8 ohm, 1550W @ 4 ohm). Does the crossover automatically run both my HF, & LF at 8 ohms or 4 ohms. As you can see from the specs below each operates at a different level.
> 
> Here is a link to the 2150 specs, it did not appear as I formatted it. http://qsc.com/products/Loudspeakers...eries/SC-2150/


 The specs link above is broken, but I found the spec sheet. Stated passive impedance is 4 ohms. As usual, the curve will swing above and below 4 ohms throughout the spectrum. Yes, in "passive" mode, the internal crossover handles everything.


xtinkshun said:


> Second question: Let's assume bi-amping would be beneficial. I'm not even sure how to do it. Is this correct? Would I wire one 4 pole Speakon cable with the +1 and -1 and use that for my HF and connect to output channel 1. Then wire my second 4 pole speakon cable with the +2 and -2 for my LF and connect that to output channel 2. Then wire them to my speakers bi-amp connections? If this is correct do I need a Y cable to connect both RCA ch 1 &2 outputs into the back of my AVR single input? And of course enter my amps setup and change to bi-amp mode.


The on-line info on this is sketchy, but from the spec sheet here under Recommended Processing, there's a 4th order Linkwitz-Riley crossover 500Hz specified for the HF section that is to occur in the "QSC Processor", in other words, an active crossover device placed ahead of the HF power amp section. There's also a 30Hz 18dB/oct HPF called for the LF section. You should not run the HF section without the recommended crossover. Apparently, when you bi-amp, you'll bypass the LF/HF crossover section, but still have whatever passive crossover handles the two horns. Fortunately, the Crown XLS series has all that available built in, just don't forget to set it.

Again, don't run bi-amped without an active crossover.


xtinkshun said:


> This would be a much cheaper option and take up less space using 3 Crown XLS amps and running them bi-amped vs. buying 6 and running each bridged mono. Leaving my Crown XLS 1500 bridged and sending 1050 watts directly to 1 speakers or "BI- AMP" the speakers and send 300 watts to the HF and sending 525watts to the LF. According to the specs that should be sufficient.


Careful...the specs are calling out maximum continuous ratings, not recommended ratings. A quick look at the sensitivity figures shows you'll need way less than 525 watts for ear-damaging levels in the average room (unless you have a large screening room with 75 seats or so). At 15' you'll max at 118dB SPL...that's pretty hot. Careful on the HF side too, compression drivers do blow.


xtinkshun said:


> IF it is just bridged how is it distributing the power through the crossover. How much wattage and what OHM to my LF and HF ?


If you use the passive setting, you have to consider the speaker as a single complex load. Power distribution to all 3 drivers has been designed for within the on-board passive network. The load, as specified, is 4 ohms, but in reality will vary, from probably a bit below 4 ohms to possibly well above 8, depending on frequency. This is normal for all multi-way speakers. But you don't have to worry or think about it.

Frankly, you should end up equalizing all this anyway, and that will change the power vs frequency distribution.


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## xtinkshun

*Re: Bi-amp these?*

Do you think its worth it to bi-amp the speakers? Would it offer more LF to the dual 15's? Im not so worried about the HF horns, those are plenty loud. Currently there is a sale on the Crown X1000 for $99.00 I could buy 3 of those for bi-amp duty. But ONLY if I can use 3 amps total. Using ch. 1 and ch.2 for bi-amping. (as asked in Question2) I don't want to buy 6 amps just for a negligible change is sound quality. I am using the speakers in a home theater room 26x16x9 with an AT 130" screen. I will use 11 ch on my Denon 4311 so I was hoping to lessen the load some. I also have a behringer I nuke 1000dsp but those fans are loud and its still cheaper to buy 3 crown X 1000's lol 
I know you said don't run bi-amped without an active crossover.... Once I change the settings on my Crown amp, that is the active crossover correct? 
I don't mind testing the speaker in bi-amp mode just to hear the difference, but I want to make sure im doing it correctly so I don't blow an amp or speakers. Assuming all is well, Is questions 2 above the correct way to wire my crown amp? Do I need an RCA Y cable to connect ch.1 and ch2. together and connect to the rear of my AVR.


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## gazoink

*Re: Bi-amp these?*



xtinkshun said:


> Do you think its worth it to bi-amp the speakers? Would it offer more LF to the dual 15's? Im not so worried about the HF horns, those are plenty loud. Currently there is a sale on the Crown X1000 for $99.00 I could buy 3 of those for bi-amp duty. But ONLY if I can use 3 amps total. Using ch. 1 and ch.2 for bi-amping. (as asked in Question2) I don't want to buy 6 amps just for a negligible change is sound quality. I am using the speakers in a home theater room 26x16x9 with an AT 130" screen. I will use 11 ch on my Denon 4311 so I was hoping to lessen the load some. I also have a behringer I nuke 1000dsp but those fans are loud and its still cheaper to buy 3 crown X 1000's lol


The XLS series has fans too. You can do the job with 3 amps, assuming bi-amped LCR. No need for 6. $99 is well below dealer cost if they're new, buy them even if you don't use them, resell and make some money. That price is literally a steal. 


xtinkshun said:


> I know you said don't run bi-amped without an active crossover.... Once I change the settings on my Crown amp, that is the active crossover correct?


Yes, you can set the Crown DSP to work as the crossover. Study the XLS manual VERY carefully, double check your wiring, and make sure your settings match what the spec sheet calls for. There is a potential for damage here if an error is made.


xtinkshun said:


> I don't mind testing the speaker in bi-amp mode just to hear the difference, but I want to make sure im doing it correctly so I don't blow an amp or speakers. Assuming all is well, Is questions 2 above the correct way to wire my crown amp? Do I need an RCA Y cable to connect ch.1 and ch2. together and connect to the rear of my AVR.


I don't see the advantage of bi-amping these in your room, especially since you have the 4311, and will do a full Audyssey Pro cal (right?). You won't need the extra power of the Crowns, the speakers are quite sensitive enough for the 4311 to drive directly.

There's not likely to be any significant audible difference between bi-amping and passive, assuming the crossover settings are done right and levels adjusted correctly, especially after Audyssey.

If you want to try it, you can use the Crown's internal dsp as the crossover. Yes, you'll Y cord the inputs.


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## ajinfla

Is this a HT setup, or....?


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## gazoink

...apparently the OP posted the same question here too.


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## gazoink

Wayne A. Pflughaupt said:


> As to whether or not it will make a difference, that’s hard for me to say. The main benefit of an active system is greater sensitivity: Passive crossovers suck up a lot of power, so for a given input wattage an active system will play much louder than a passive system will. However, you don’t fully get this benefit with this QSC speaker because in biamp mode the mid/high section remains passively filtered.
> 
> Regards,
> Wayne


Ah, the old "passive crossovers suck power" myth. No, that's not how they work, and I would have to disagree with "Passive crossovers suck up a lot of power", and "an active system will play much louder". That would imply a passive crossover diverts the unwanted energy from a driver by absorbing energy and converting it to heat. That's not what they do. They divert energy from a driver by increasing impedance, in effect, blocking energy. The factor to be concerned with is the insertion loss of the crossover, which is quite tiny. If it weren't, we'd all have heat sinks on our crossovers with cooling fans. 

It does depend on what you call "a lot of power" or "play much louder", however. The passive sensitivity of the 2150 is 99dB/1W/1m, the individual sections are at 100dB/1w/1m for the LF, and 102dB/1w/1m for the HF pair, which actually has to be compensated for in the active crossover to voice the speaker correctly in active mode. So, it's actually a 1dB difference, which sounds like a lot in terms of watts, but barely perceptible in terms of loudness.

Here's the data sheet. 

Note also the sheet calls for an active Linkwitz-Riley crossover for the HF pair in active mode.

The advantage of active crossovers is the ability to fine-tune without swapping expensive passive components. It's not a power advantage.


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## xtinkshun

*Re: Bi-amp these?*

Thanks for your input. Its probably more trouble than its worth. The speakers actually had a "real" bi-amp crossover not just 4 binding posts. lol Yes, I do get plenty of power from my Denon I was just concerned when I run all 11 channels if Ill start to lose watts output. I know the manual states each channel "discrete" but still. So I wanted to ask before I went through the hassle of a futile attempt.


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## xtinkshun

I didn't meant to post twice but I wasn't sure "where" the post belonged. Its for home theater use but im using Pro speakers and Pro gear. "The Dilema" Im sure when these were built by QSC they were not meant for the "home AVR" but rather QSC pro gear. Although they do recommend this setup for "home" use. But im sure they want to sell their amps along with the speakers. Im sure they would recommend bi-amp as well. So I was curious if it would really make a difference, would it develop a larger more 3d soundstage, clearer vocals, etc. Running my amps in bridge mode certainly plays them louder. Not only can I hear it, but my spl meter proves it. So that's what had me thinking about bi-amping. I was curious if it would produce more bass given the extra boost of clean wattage directed ONLY to the LF and perhaps the HF would benefit. But it sounds like more myth than legend. lol It may be a few DB louder but it wont be any cleaner sounding and having extra power on tap doesn't sound like it will be use for anything. 
Thank your for the replies.


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## xtinkshun

is it beneficial to run each crown amp in bridge mode for the purpose of headroom and less chance of clipping? I don't care about "loudness" they are plenty loud


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## xtinkshun

ajinfla said:


> Is this a HT setup, or....?


This is a home theater setup. but now I am being told that pro gear setup for bridged mono is NOT a good choice to connect to my speakers. they are better left using my Denon AVR outputs (NO PRO GEAR). That its not the proper use of the equipment. Now I am even more confused. OK, if you say bi-amping wont do anything, Im ok with that.... 
But what is the difference if I use my AVR outputs. 150wpc OR if I use my Crown bridged mono (1050 wpc 8 ohms or 1550 wpc 4 ohms)? Other than playing a louder SPL which I will use Audyssey room correction, will it damage my speakers or AVR in some way?
The speakers are Pro speakers so why would pro amps be a bad idea? I was basically told to buy a 2ch, 3 ch, or 5ch commercial amp and not use any pro amps unless they are used with a mixer or used for DJ type use. They are NOT meant for Home Theaters? HUH


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## NBPk402

xtinkshun said:


> This is a home theater setup. but now I am being told that pro gear setup for bridged mono is NOT a good choice to connect to my speakers. they are better left using my Denon AVR outputs (NO PRO GEAR). That its not the proper use of the equipment. Now I am even more confused. OK, if you say bi-amping wont do anything, Im ok with that....
> But what is the difference if I use my AVR outputs. 150wpc OR if I use my Crown bridged mono (1050 wpc 8 ohms or 1550 wpc 4 ohms)? Other than playing a louder SPL which I will use Audyssey room correction, will it damage my speakers or AVR in some way?
> The speakers are Pro speakers so why would pro amps be a bad idea? I was basically told to buy a 2ch, 3 ch, or 5ch commercial amp and not use any pro amps unless they are used with a mixer or used for DJ type use. They are NOT meant for Home Theaters? HUH


Have you checked out this... http://www.hometheatershack.com/for...ing-most-pro-audio-equipment-your-system.html I think the main issue is getting the gain correct. I have the Denon 4520, and I do not have the correct gain with my Yamaha P7000S amp for my subs. I found this out when I went to calibrate it with Audyessy. When I go to calibrate I have to turn the gain all the way up just to get the preferred 75db that Audyessy needs. It still sounds great as i don't need much power to hit reference bass levels but I think I would be better off with a balanced AVP or a non balance power amp.


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## xtinkshun

ellisr63 said:


> Have you checked out this... http://www.hometheatershack.com/for...ing-most-pro-audio-equipment-your-system.html I think the main issue is getting the gain correct. I have the Denon 4520, and I do not have the correct gain with my Yamaha P7000S amp for my subs. I found this out when I went to calibrate it with Audyessy. When I go to calibrate I have to turn the gain all the way up just to get the preferred 75db that Audyessy needs. It still sounds great as i don't need much power to hit reference bass levels but I think I would be better off with a balanced AVP or a non balance power amp.


I have plenty of power for my subs I was looking for more kick going into my dual 15" woofer located inside my QSC 2150 speakers. I'm not if the crossover inside itself is limiting the "punch" or not. That's why I was asking about bi-amping. To allow the crossover inside my crowns xls1500 to provide the LF to those speakers or I can use my Inuke 1000dsp. (either or, doesn't matter) but before I went through the hassle of doing so, I wanted to know if it is worth it? From those who have done it. The owners of Pro speakers with pro gear. Not the best buy owner that bought some off the shelf speakers and seen 4 terminals and said, hey, I'll bi-amp lol


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## Wayne A. Pflughaupt

gazoink said:


> Ah, the old "passive crossovers suck power" myth.
> 
> The advantage of active crossovers is the ability to fine-tune without swapping expensive passive components. It's not a power advantage.


Since you’re using the speaker’s spec sheet to prove your point, I have to wonder if you have any hands-on experience relating to this? If so you’d know that if you connect a driver through a passive crossover, then bypass the crossover and connect the speaker wire directly to the driver itself, that there is a noticeable increase in SPL.

“Sucking power; “blocking energy;” insertion loss” – call it what you will but it’s no myth that a given speaker with passive crossovers will deliver noticeably less output with a given wattage than the same speaker ran as active with electronic crossovers. It’s common knowledge in pro audio circles (and I expect DIY home speaker-building circles as well), which is why the professional sound industry has used active systems in their touring PA systems, practically universally, for literally decades.

I have my doubts that even DIY home speaker building enthusiasts endure the significant expense of additional amplifiers and electronic crossovers simply to avoid swapping out comparatively cheap “expensive passive components.”

Regards,
Wayne


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## Wayne A. Pflughaupt

xtinkshun said:


> I was with you all the way to the very end Wayne, Im not sure about your last sentence. What do you mean by.. _However, you don’t fully get this benefit with this QSC speaker because in biamp mode the mid/high section remains passively filtered._


See previous post – you can’t get the primary advantage of an active system – increased efficiency (read SPL) - if passive elements remain in place between two of the drivers (the MF and HF in this case). 




> Does this mean bi-amping them would be the same as bridged mono?


Not following your thought there – biamping has to do with the speaker, bridging has to do with the amplifier. Bi-amping requires two amplifier channels; that’s obviously impossible to accomplish if an amp has been bridged for mono operation.




> Before we get too technical since I will not be buying 6 amps just to "TRY" the bi-amped.


If you’re talking about six stereo amps all bridged mono, that would be a colossal waste. The increased efficiency bi-amping brings means you can get the same SPL output with less power, so there’s no good reason to use bridged amps. I remember reading literature from an audio manufacturer many years ago (forget the exact product or manufacturer) that an active three-way speaker would get the same output from 25 watts per driver (i.e. 75 watts total) as it would with passive crossovers and 250 watts.

That said, the big uncertainty with this particular QSC speaker is the hybrid active/passive thing you get with its biamp mode. The biamp mode must bring some benefit or I doubt QSC would bother to make it available, but with passive filters left in place I don’t see how it could be as effective from a maximum SPL perspective as a fully active system.




> My intention was to use both channels on my Crown XLS amp to bi-amp each speaker. ie. ch. 1 to my HF and ch2. to my LF is that possible?


Certainly. However it’s more typical to put say, the high freq drivers on their own, lower powered amplifier, as it’s more efficient from cost and power standpoint. However, for the sake of experimenting you could do things as you’ve proposed, bi-amping with a single amplifier.




> IF its possible was my above description for wiring correct or incorrect.
> Or would I need a piece of equipment between my amp and speaker, ie external crossover?


Yes an external electronic crossover will be required to replace the passive one, either built into the amplifier itself or a stand-alone unit.




xtinkshun said:


> The speakers are Pro speakers so why would pro amps be a bad idea? I was basically told to buy a 2ch, 3 ch, or 5ch commercial amp and not use any pro amps unless they are used with a mixer or used for DJ type use. They are NOT meant for Home Theaters? HUH


”HUH” is right. That person has no idea what he’s talking about, unless he was saying that your AVR doesn’t have enough signal voltage from its main-channel RCA outputs to drive the amps. Refer to Part 7 of the article ellisr63 linked to determine whether or not that’s an issue with your AVR.

Regards,
Wayne


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## xtinkshun

Thank you Wayne, that made much more sense. Im not sure what benefit I would receive from bi-amping. I was curious since the option is actually built into the crossover. I was hoping for more LF power/excurions/head room. When I am running with my AVR only, I hear them clip every now and then during an intense explosion scene. Ie, Start Trek, Pearl Harbor (during the attack) Im not sure if my Denon just cant offer enough juice or if its a setup issue. I was hoping bi-amping would solve the problem. In the mean time I could just run them bridged mono and see if I get the same result. Crown X1000 are still on sale so I could buy 3 of those for either bi-amp duty or bridged mono. 
Wayne - Is there a difference between running the Crown amps in Stereo vs. bridged?
Just to be clear I am NOT looking for more SPL (the speakers are loud and efficient) I am looking for cleaner and more headroom. The safest way possible of course. 

http://www.musiciansfriend.com/pro-audio/crown-x1000-stereo-2x300w-power-amp
Guaranteed Minimum Power: 300W (per channel) @ 4 ohms / 200W (per channel) @ 8 ohms / 600W bridge mono @ 8 ohms


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## gazoink

xtinkshun said:


> is it beneficial to run each crown amp in bridge mode for the purpose of headroom and less chance of clipping? I don't care about "loudness" they are plenty loud


"Beneficial" is subjective. Higher power amps raise the maximum peak distortion-free SPL, but the current combination of speakers at 99dB/1W/1m and 150WPC should provide somewhere around 7dB of clean headroom when the system is played at a calibrated theatrical reference level and the listening position is about 15' away. You can bump that another 8dB, but why would you?


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## gazoink

Wayne A. Pflughaupt said:


> Since you’re using the speaker’s spec sheet to prove your point, I have to wonder if you have any hands-on experience relating to this? If so you’d know that if you connect a driver through a passive crossover, then bypass the crossover and connect the speaker wire directly to the driver itself, that there is a noticeable increase in SPL.


Yes, but it depends on the crossover. Some more, some less. In the case of the QSCs, it's less.



Wayne A. Pflughaupt said:


> “Sucking power; “blocking energy;” insertion loss” – call it what you will but it’s no myth that a given speaker with passive crossovers will deliver noticeably less output with a given wattage than the same speaker ran as active with electronic crossovers. It’s common knowledge in pro audio circles (and I expect DIY home speaker-building circles as well), which is why the professional sound industry has used active systems in their touring PA systems, practically universally, for literally decades.


I'm not disputing the proliferation of active crossovers and bi/tri-amping in pro sound, done it myself for decades. But it's never been simply a max SPL issue, it's about precision tuning, time-aligning, pattern control, etc. Yes, it's nice to avoid a bit of insertion loss, but there are SO many other issues solved, and for pro systems crossover insertion loss has never been more than a dB or so. Probably different for consumer speakers. You also have to watch out for the level matching done in the crossover. Sometimes that's misinterpreted as insertion loss when it's actually part of voicing.

In the context of this thread, and the QSC 2150, citing crossover power loss seems a bit pointless.


Wayne A. Pflughaupt said:


> I have my doubts that even DIY home speaker building enthusiasts endure the significant expense of additional amplifiers and electronic crossovers simply to avoid swapping out comparatively cheap “expensive passive components.”


You might not say that if you'd tried to hand-tune a passive crossover. MUCH easier, faster, and more accurate to dial in DSP values, or in the old days, adjust an active filter. Ever seen the schematic for a 4th order passive crossover? Then, consider what you'd have to do to do something like adjust frequency, much less phase-optimize it. Simply not going to happen in the passive world.


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## ajinfla

Threads merged. Xtinkshun, please only post topics once in your desired forum, I hate extra work.


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## ajinfla

*Re: Bi-amp these?*



xtinkshun said:


> Thanks for your input. Its probably more trouble than its worth. The speakers actually had a "real" bi-amp crossover not just 4 binding posts. lol Yes, I do get plenty of power from my Denon I was just concerned when I run all 11 channels if Ill start to lose watts output. I know the manual states each channel "discrete" but still. So I wanted to ask before I went through the hassle of a futile attempt.


It's impossible to say whether it's "worth" doing, but their isn't much harm, other than to your wallet.
Will alleviating your Denon of a few channels give you more headroom? Yes. But given this is HT, not an arena and your speakers _*very high*_ voltage sensitivity, unless you plan on going deaf, you may never notice. That said, again, there is no harm in doing so.

cheers


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## gazoink

Assuming listening at theatrical reference level 85dB SPL, there's 20dB between that and the maximum signal recorded in a soundtrack, that's a max of 105dB SPL. With the Denon and the QSC speakers, the OP is already somewhere around 6dB above that for power amp clipping. That means he's 6dB away from it ever happening because no program material will ever go beyond 105, unless played above the 85dB ref. Moving to the power amps adds another 6 to 8dB of additional power amp headroom that will never be used by any program material if played at ref 85dB. 

That's the theatrical reference level, which is too loud for home listening. Nobody needs 12-14dB of headroom.


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## ajinfla

What are you basing those numbers on?


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## gazoink

ajinfla said:


> What are you basing those numbers on?


Amp power, speaker efficiency, assuming 3 speakers at an arbitrary distance of 15' from the listening position. The film reference level is 20dB below digital clipping.

Edit: sorry that should be film reference is -20dBFS.
edit2: ...which corresponds to 85dB SPL at the mix position in a dub stage and mid-seating in a calibrated theater.


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## xtinkshun

I connected my speakers bi-amped and didn't really care for the sound. I was using an Inuke 1000dsp so I could change the fields as I went. I did hear some differences here and there but nothing earth shattering and certainly NOT worth the headache of nearly blowing a speaker. SO, new question... sorta. Would connecting my speakers in bridged mode be more beneficial than using my Denon AVR? I will be running an 11ch setup (not 100% sold on Atmos) but if I were, it would be an 11 ch Atmos player as well. 

SO, will I hear a difference if I bridge my speakers? will 600 wpc sound any different than 140wpc? I am not looking for higher SPL, im asking about more clarity and detail with vocals, instruments, sounds, explosions, etc. I already know it will play louder than I would ever want. 

Does it really all come down to the speakers sensitivity? ie. if your speakers are 100db sensitivity connecting a 500wpc Krell amp will sound the same as a 600 watt bridged crown and a 140wpc Denon. due to the 100db sensitivity. 

Secondly if your speakers are 90db sensitivity and you connect the same 3 amps then you WILL hear a very noticeable difference with clarity, soundstage, vocals, etc and the Krell would be the clear winner?

I ask this question because I owned a pair of B&W 802D speakers and when powered with a standard AVR they sounded like , but when I connected them with a McIntosh 200wpc amp they really opened up and sounded incredible. completely different speakers. I guess this is the point/question I am trying to understand. Perhaps with pro speakers it will make no difference due to the type of atmosphere they are played in.


----------



## ajinfla

gazoink said:


> Amp power, speaker efficiency, assuming 3 speakers at an arbitrary distance of 15' from the listening position.


That's quite a few assumptions, unless you have actual measured performance data, especially given the circumstances of all channels driven.

cheers,


----------



## ajinfla

xtinkshun said:


> I connected my speakers bi-amped and didn't really care for the sound. I was using an Inuke 1000dsp so I could change the fields as I went. I did hear some differences here and there but nothing earth shattering and certainly NOT worth the headache of nearly blowing a speaker.


I can't imagine you hearing not being close to blowing than those speakers, unless you are seriously overboosting bass, etc.



xtinkshun said:


> SO, will I hear a difference if I bridge my speakers? will 600 wpc sound any different than 140wpc?


Amplifiers are bridged, not speakers. It is extremely doubtful you are getting anywhere near 140w from the Denon, given all channels driven, at best maybe 60% efficiency from its AB amplifiers and a 780 watt maximum power draw. That's why I asked gazoink about his numbers. I don't think the complexity of the situation is understood here.



xtinkshun said:


> I am not looking for higher SPL, im asking about more clarity and detail with vocals, instruments, sounds, explosions, etc. I already know it will play louder than I would ever want.


For any of that to happen, the Denon would have to be driven into non-linear behavior vs the Inuke. Without data, it's impossible to say that's happening. Unless the speakers have <4ohm minimum impedance coupled to a complex phase angle, it's unlikely. Not impossible, but unlikely, like I said, given their very high voltage sensitivity and the fact that you are in a "HT" room, not an arena.
*IF* there were both speaker and amp *measured* data available, a more definitive answer would be possible. But there isn't.

cheers,


----------



## ajinfla

xtinkshun said:


> I ask this question because I owned a pair of B&W 802D speakers and when powered with a standard AVR they sounded like , but when I connected them with a McIntosh 200wpc amp they really opened up and sounded incredible. completely different speakers. I guess this is the point/question I am trying to understand. Perhaps with pro speakers it will make no difference due to the type of atmosphere they are played in.


With those speakers less guesswork is required, because we _do_ have one piece of data:








..and Atkinson spells it out: _The B&W's impedance plot (fig.1) reveals the speaker to be moderately difficult to drive, with a magnitude that drops to 3 ohms throughout the upper bass and an awkward combination of 4 ohms and –50° electrical phase angle at 60Hz_.
So we can chalk up the differences you perceived to a couple possibilities:
1) Your expectations, sighted, uncontrolled test format.
2) Non-linear behavior of the AVR amplifier due to load/drive levels.
3) Linear behavior of the Mac amplifier due to load/drive levels.
It would be nice if there were nice easy answers to all this stuff, but there isn't.
That's why I said, no harm to biamping other than wallet...or misuse/poor implementation of course.

cheers


----------



## xtinkshun

ajinfla said:


> Amplifiers are bridges, not speakers. It is extremely doubtful you are getting anywhere near 140w from the Denon, given all channels driven, at best maybe 60% efficiency from its AB amplifiers and a 780 watt maximum power draw. That's why I asked gazoink about his numbers. I don't think the complexity of the situation is understood here.
> 
> cheers,


That's was a mis-spell while typing. I meant bridging my amplifier @600wpc (which I am not sure is really 600 wpc)

Perhaps that was the reason I heard a very discernible difference between my Onkyo AVR and the McIntosh MC205. The onkyo was only using approx. 60% of its total wpc while the Mac was using all 200wpc? 
could this be why? People spend quite a bit of money on krell, Mac, Parasound, etc to add external amps and they DO hear a difference in output via their speakers when compared to the stock AVR they own. Im just curious if for example a Crown amp putting out 300wpc would sound the same as a Emotiva XPA2 which is a 300wpc amp. Im certain we have Emotiva owners that also own pro gear. Maybe Ill ask that question elsewhere.


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## NBPk402

xtinkshun said:


> That's was a mis-spell while typing. I meant bridging my amplifier @600wpc (which I am not sure is really 600 wpc)
> 
> Perhaps that was the reason I heard a very discernible difference between my Onkyo AVR and the McIntosh MC205. The onkyo was only using approx. 60% of its total wpc while the Mac was using all 200wpc?
> could this be why? People spend quite a bit of money on krell, Mac, Parasound, etc to add external amps and they DO hear a difference in output via their speakers when compared to the stock AVR they own. Im just curious if for example a Crown amp putting out 300wpc would sound the same as a Emotiva XPA2 which is a 300wpc amp. Im certain we have Emotiva owners that also own pro gear. Maybe Ill ask that question elsewhere.


When you were comparing an external amp to an internal amp...
Are you calibrating with Audyessy?
If not are the levels set the same with a SPL meter?


----------



## gazoink

ajinfla said:


> That's quite a few assumptions, unless you have actual measured performance data, especially given the circumstances of all channels driven.
> 
> cheers,


I'd agree if this was consumer gear, but it's not. Pro gear specs are actually quite a bit more accurate because we have to design huge expensive systems around them, and is in fact based on measured performance data. It's a different world than consumer audio where specs are just selling points. In the pro field we have real engineering specifications to work with. 

In the pro world you can just take a chance, you have to know as much as possible about what you're working with before you begin the design. The only figures in doubt in the calculations are listening distance and a possible fudge factor in speaker sensitivity, but pro specs for speakers are generally dead on within +/- .5dB. All of that can go into modelling software, and you can in fact hit the design goal pretty well.

None of this works with consumer gear reliably, though. Too many fudged specs that no customer will every try to verify. As pros we verify the performance of the design with measurements, and if it doesn't match there are some very hard questions asked of manufacturers. Accountability, etc. Those uncomfortable situations are reduced by working with accurate specifications.

So other than listening distance, there are no real assumptions here. Pretty sure everything calculated would fall within a dB of reality.


----------



## ajinfla

xtinkshun said:


> That's was a mis-spell while typing. I meant bridging my amplifier @600wpc (which I am not sure is really 600 wpc)


...and you quoted my typo, S being next to D on the keyboard...



xtinkshun said:


> Perhaps that was the reason I heard a very discernible difference between my Onkyo AVR and the McIntosh MC205.


Perhaps, though other possibilities exist, as I stated.



xtinkshun said:


> The onkyo was only using approx. 60% of its total wpc while the Mac was using all 200wpc?


No.
60% represent about the maximum efficiency of a typical AB amp. Your Denon has a max _total power_ draw of 780 watts. That means around a max total of 468 watts output (60%) available...so _with all 9 channels driven_, around 50 watts per channel, _ballpark_. However, it is extremely unlikely with dynamic mch sound for all channels to be driven equally. Some channels will require more, others less, dynamically (changing vs time).
In 2ch mode, it's likely the Denon can deliver the full "rated" 140w continuous (rms), so 280w total. Probably more into lower impedance (like 4 ohm), even more peak (short duration bursts). Same applies to the Onkyo.
There are ways to test all that, but it is seldom done.



xtinkshun said:


> People spend quite a bit of money on krell, Mac, Parasound, etc to add external amps and they DO hear a difference in output via their speakers when compared to the stock AVR they own.


Yep and there are many possibilities as I have said.



xtinkshun said:


> Im just curious if for example a Crown amp putting out 300wpc would sound the same as a Emotiva XPA2 which is a 300wpc amp.


Should, barring non-linear behavior into load vs output. 
But there is far more to "sound" than soudwaves/soundfields, as far as human beings are concerned.

cheers


----------



## gazoink

xtinkshun said:


> I connected my speakers bi-amped and didn't really care for the sound. I was using an Inuke 1000dsp so I could change the fields as I went. I did hear some differences here and there but nothing earth shattering and certainly NOT worth the headache of nearly blowing a speaker. SO, new question... sorta. Would connecting my speakers in bridged mode be more beneficial than using my Denon AVR? I will be running an 11ch setup (not 100% sold on Atmos) but if I were, it would be an 11 ch Atmos player as well.
> 
> SO, will I hear a difference if I bridge my speakers? will 600 wpc sound any different than 140wpc? I am not looking for higher SPL, im asking about more clarity and detail with vocals, instruments, sounds, explosions, etc. I already know it will play louder than I would ever want.
> 
> Does it really all come down to the speakers sensitivity? ie. if your speakers are 100db sensitivity connecting a 500wpc Krell amp will sound the same as a 600 watt bridged crown and a 140wpc Denon. due to the 100db sensitivity.
> 
> Secondly if your speakers are 90db sensitivity and you connect the same 3 amps then you WILL hear a very noticeable difference with clarity, soundstage, vocals, etc and the Krell would be the clear winner?
> 
> I ask this question because I owned a pair of B&W 802D speakers and when powered with a standard AVR they sounded like , but when I connected them with a McIntosh 200wpc amp they really opened up and sounded incredible. completely different speakers. I guess this is the point/question I am trying to understand. Perhaps with pro speakers it will make no difference due to the type of atmosphere they are played in.


Seems like all this has been answered as well as possible given the limited data. Now, you're talking about hearing differences between different amplifiers, speakers, wiring methods...the permutations boggle. 

Perhaps you should just try it and see. Part of the final experience...a big part...is knowing what you're listening to, and the bias that impresses. Some will love Krell regardless...because it's Krell, and for no other verifiable reason. 

The statements definitive statements like "if your speakers are 90db sensitivity and you connect the same 3 amps then you WILL hear a very noticeable difference with clarity, soundstage, vocals, etc" just are not definitive at all, they're cojecture or opinion or both. We don't need to get into vague terms linke "soundstange" and "clarity".

All speakers play in the same atmosphere, because that mix is all we have on the planet.

I think I'm kinda done here...


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## ajinfla

gazoink said:


> So other than listening distance, there are no real assumptions here. Pretty sure everything calculated would fall within a dB of reality.


Would you mind showing the actual numbers and equations used? I like math.
I couldn't find any ACD powercube type info for the Denon, nor FR and impedance for the QSC. Or his room, including openings, dimensions, walls, ceiling and floor lossiness.
Thanks.


----------



## xtinkshun

You both make interesting points. Im going to walk into a hi-fi store carrying my crown amp and ask for an a/b/ comparison. Their Mac room its ALL treated and has room perfect via the mx 152. I bet they would look at me like im crazy lol 
That would be the ultimate test though.

I know for a fact I heard a difference when they disconnected the onky nr1000 something and connected the MC205. No cable switches, no calibrations changes. just swapped amps. used the pre outs on the onkyo too. and anyone with ears could hear a night and day difference. Im a curious person and like to know WHY.. Not just because. lol I can understand manufacturers lying about their specs and maybe it was only using 50wpc to the B&W 802D. All I know, is their WAS a difference is sound quality. Not which was louder, but depth of soundstage, etc. I could actually pick out where the singer was in the room, not in the speaker. lol I could HEAR her breath in the mic and the piano sounded real. I cant believe it was all due to a McIntosh amp. NO magic inside, just watts. I guess I am getting a little off track. but im looking for the best sound quality setup, NOT loudest system. Whether that is running the Denon to all channels or running my Crown in 2ch Stereo mode or running each Crown bridged..... It didn't think it would get this complicated.. sorry guys. but Im still learning as I go.


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## ajinfla

xtinkshun said:


> I bet they would look at me like im crazy lol
> That would be the ultimate test though.


They might. 
Unfortunately, it would have precisely zero relevance to your situation, which involves a Denon 4311, QSC 2150 speakers and biamping....in your room.
Well, other than the sighted, uncontrolled evaluation part.

cheers,


----------



## gazoink

ajinfla said:


> Would you mind showing the actual numbers and equations used? I like math.
> I couldn't find any ACD powercube type info for the Denon, nor FR and impedance for the QSC. Or his room, including openings, dimensions, walls, ceiling and floor lossiness.
> Thanks.


I'll consider it, but frankly I don't have time for a witch hunt. If there's something specific you disagree with, or you think I'm off by more that a few dB, let me know. 

We don't need FR and impedance to come up with basic SPL. 

Room dimension were posted here. No, we don't have room orientation, but with the 103" AT, it's probably front at the narrow end. Hence, my arbitrary 15' listening distance figure. But it doesn't matter anyway. Move the listening point a few feet, move the results a dB or so, big deal. 

Ceiling and floor "lossiness"...you looking for absorption coefficient? STC? What? Doesn't matter anyway, the 2150 is a 90x40 basic system with -6dB at the edges, not likely to bother with the floor and ceilings much. 

ACD, if you really wanted to go there, probably woudn't change the total power to the fronts by more than a dB or so, something on the order of 150W to 120W (1dB), if it changes much at all, the Denons are pretty well engineered. But regardless, in HT, 70% of the total sound field comes from one channel, the center. Yet, when calibrating systems, a shaped pink noise reference is used, typically from all channels. In this case, I used just the front 3 because in the real world that accounts for 90% or more of the total sound field energy, especially if integrated over time.

Again, I'm out of time here. Got real work to do. If you think I'm so way off, fine, I'll give you a fudge factor of 3dB, and we'll still be talking way more power amp headroom that would ever be required at any time in the HT with those speakers.

If you think all this calculates out to a different answer that's way off my figures and justifies that much more power amp, fine, just post your results and then we'll have both. Otherwise, I'm still at: the power amps are unnecessary in this room with these speakers to hit higher than references SPL. And that's all the time I have today...sorry.


----------



## ajinfla

Thanks. I think you made lots of assumptions, whereas I would prefer to rely only on real data, of which there is almost none that I could find. None for the Denon (other than max draw), none for the QSC, none for the room (ok, I missed the rough dimensions earlier). So I really have nothing to compare vs your assumptions. 
But I think you're right that we've spent enough time speculating...and pretty much agreed from my first post that it was highly unlikely he would benefit, if he wanted to preserve his hearing.

cheers,


----------



## ajinfla

gazoink said:


> In this case, I used just the front 3 because in the real world that accounts for 90% or more of the total sound field energy, especially if integrated over time.


That's interesting, a 90% power distribution in 9ch configuration. I wouldn't have thought it was that high. If you have a link to how that is derived, I'd appreciate it, thanks.

cheers


----------



## gazoink

ajinfla said:


> That's interesting, a 90% power distribution in 9ch configuration. I wouldn't have thought it was that high.


70% center (google it)
20% L/R 
10% surround, height, whatever

Remember, this is _integrated over time_, not instantaneous.


xtinkshun - Wed said:


> If you have a link to how that is derived, I'd appreciate it, thanks.
> 
> cheers


Google it. The center's contribution to the mix is well known, estimates range from 60% to 80%, and described by many sources, including I believe Dolby.
No I'm not taking time to google and post links. See next post.


----------



## gazoink

ajinfla said:


> Thanks. I think you made lots of assumptions, whereas I would prefer to rely only on real data, of which there is almost none that I could find. None for the Denon (other than max draw), none for the QSC, none for the room (ok, I missed the rough dimensions earlier). So I really have nothing to compare vs your assumptions.
> But I think you're right that we've spent enough time speculating...and pretty much agreed from my first post that it was highly unlikely he would benefit, if he wanted to preserve his hearing.
> 
> cheers,


I'm sorry if you think there's a differentiation between real data and engineering data for the QSC. Their specs are derived from tests, and are close enough(read: dead-nuts-on) to design with and predict quite well. I think only those experiences in pro audio will understand, though.

I agree the specs on the Denon are a bit sketchy, but the actual power to a load could be off by 20%, and that would be just under a 1dB error. I really don't see the point of belaboring specs just to get a reasonable SPL prediction. 

There's a long way between assumptions and engineering data. Perhaps the gap is filled by experience.

And this, I promise, is my last contribution to the thread. You may now bash at will.


----------



## ajinfla

gazoink said:


> 70% center (google it)
> 20% L/R
> 10% surround, height, whatever
> Remember, this is _integrated over time_, not instantaneous.
> Google it.


I did _before_ asking you, which lead to DTS Neo X, which said nothing about power distribution in 11ch. I was hoping for some sort of white paper where you derived those numbers for 11ch reproduction.
If you don't have one, that's fine, thanks.


----------



## ajinfla

gazoink said:


> There's a long way between assumptions and engineering data. Perhaps the gap is filled by experience.


Perhaps, but I know the difference between "specs" and measurements. I also know what "nominal" and "average" is, regarding both impedance and frequency response, etc, etc.
I like to see electrical phase and derive power vs load to get (free space) SPL vs frequency, mathematically, not by "experience". That is simply my preference, YMMV.



gazoink said:


> And this, I promise, is my last contribution to the thread. You may now bash at will.


Sorry to hear that, I enjoy reading you contributions as they appear quite knowledgeable, but it seems you regard my rigor as "bashing". That certainly isn't my intent, especially when asking for references where I (and readers) might learn something. Thanks for your participation anyway, sincerely.

cheers


----------



## Wayne A. Pflughaupt

gazoink said:


> Yes, [differences in SPL output between active and passive speakers] depends on the crossover. Some more, some less. In the case of the QSCs, it's less.
> 
> In the context of this thread, and the QSC 2150, citing crossover power loss seems a bit pointless.


When I made the comment about out power loss with passive crossovers I was speaking generally, not about this particular speaker; apparently it escaped your notice. Okay, maybe it’s technically more accurate to describe the loss in output in other terms. I’ll give you that, even if the ultimate real-world result is the same - which makes the big to-do you're making about this pointless.

You’re putting a lot of trust in QSC’s spec sheet for this speaker; I’m not as confident that it’s only going to show a 1 dB improvement when run bi-amped. In any event, thanks for backing up my original contention that passive crossovers have a noticeable loss in output compared to active crossovers.




gazoink said:


> I'd agree if this was consumer gear, but it's not. *Pro gear specs are actually quite a bit more accurate* because we have to design huge expensive systems around them, and is in fact based on measured performance data. It's a different world than consumer audio where specs are just selling points. *In the pro field we have real engineering specifications to work with.*


Apparently you’ve never heard of Behringer or Alesis? (Let the back-pedaling begin.)

Regards,
Wayne


----------



## xtinkshun

Not trying to start any arguments but I thought Pro amps specs were grossly overstated. I recall reading in a thread somewhere that someone had done actual scientific testing of a few amps. Behringer being one of a few choices. I believe Behringer claims was 1000 watts at 4 ohms but in actuality it was more like 1/3 the power they were claiming. In fact ALL were off by quite a large margin. Im not sure if the same is true for commercial amps or not. I believe they may inflate the number or misinform the public when they state 150wpc. When in fact it may only be 2 channels driven at 150 watts then drops from there. By the time to get to 5 channels, your getting 50wpc driven equally to ALL channels. I have also read independent bench tests where again (scientifically tested) proved the amount of WPC. Emotiva, McIntosh, Krell, Parasound. Hell pretty much any amp costing $4,000 + is probably accurate when it comes to WPC. Not sure I can agree that a Behringer amp is producing 1000 watts bridged. (lets test it against a 1K emotive or McIntosh)


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## gazoink

I'm sorry to break a promise, but this needs attending.

Behringer and Alesis are not considered "pro" by any actual audio professional. We simply never touch them. They're considered "pro" by home recording fans, and the music market, small recording studios. Yes, they're a great deal for price vs function, but they're so fragile that you can't hang the success of a large system affecting thousands of people on them. They are considered "pro" only because they have the right I/O style. That's not the only thing required for use in real pro installations.

I haven't even looked at Alesis for a long time, but the Behringer specs are pretty much non-existent in most cases. There's nothing on which to base a design, certainly nothing accurate.

QSC is real pro gear. JBL has a real pro line. The specs are the result of test data in a real acoustic or electronic lab which test capabilities usually far exceed those of any hobbyist, and they know engineers will be checking them. Sensitivity, for example, is measured in anechoic chambers, with instrumentation with traceable calibration references. That's a long way from "my SPL meter was calibrated with another SPL meter". Ever price an SPL meter calibrator? If you did, you'd see on example of the difference between the real Pro and consumer environment.

That's how you design huge systems, there's no testing until the design has been installed, there can't be, and it's too late to turn back. Pro gear specs are accurate, or conservative where appropriate, that's why it's successful in the pro market, and it's to the manufacturer's benefit to publish accurate specs. Power, as an example, is usually rated slightly conservatively. 

I'll respond to others in PM in a now lame attempt to say out of this thread. 

And now, everyone can post examples they know of where Behringer and Alesis have been used professional...thus missing the point...again.


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## mechman

You can disagree, correct and discuss without condescension. Let's keep that in mind as we post! :foottap:


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## xtinkshun

I don't understand why you feel people would "bash" you unless they want to be banned from this site. I myself have only recently started using PRO amps with my Home Theater setup. Why should I pay $4,000 for a 2 ch. 200wpc amp if I can buy a pro amp for $300.00 BUT I assume their must be a reason how they justify the price difference. Is It looks, brand name, etc etc. OR in a blind test would the sound be indiscernible. You said Behringer is NOT a PRO amp. Why? Which brands are considered PRO amps and what makes them pro amps compared to other companies. Just to keep it simple we can discuss Behringer, Crown, QSC,. Are the internal components different, does that create a different sound? Is it the price? if QSC amp cost $800 then will it sound better than Crown and Behringer? Im curious as it relates to facts. I assume amps like Parasound, Krell, etc are purchased for their names more than sound quality which makes me wonder IF I walked into my Hi-Fi dealer carrying a Crown X 1000 fridged @ 600watts WILL is sound identical to the McIntosh MC601 monoblock? If not WHY? They are both 600 watts @ 8 ohms. *I really am curious, not trying to be a smart azz*


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## NBPk402

xtinkshun said:


> I don't understand why you feel people would "bash" you unless they want to be banned from this site. I myself have only recently started using PRO amps with my Home Theater setup. Why should I pay $4,000 for a 2 ch. 200wpc amp if I can buy a pro amp for $300.00 BUT I assume they must be a reason why to justify the price difference. Is It looks, brand name, etc etc. OR in a blind test would the sound be indiscernible. You said Behringer is NOT a PRO amp. Why? Which brands are considered PRO amps and what makes them pro amps compared to other companies. Just to keep in simple we can discuss Behringer, Crown, QSC, and JBL amps. Are the internal components different, does that create a different sound? Is it the price? if QSC and JBL cost $800 then they are better than Crown and Behringer? Im curious as it relates to facts. I assume amps like Parasound, Krell, etc are purchased for their names more than sound quality which makes me wonder IF I walked into my Hi-Fi dealer carrying a Crown X 1000 fridged @ 600watts WILL is sound identical to the McIntosh MC601 monoblock? If not WHY? They are both 600 watts @ 8 ohms. *I really am curious, not trying to be a smart azz*


I remember years ago Stereophile reviewed a Crown pro amp, and it was every bit as good as Hi End home amps for way less money.


----------



## Wayne A. Pflughaupt

gazoink said:


> I'm sorry to break a promise, but this needs attending.
> 
> Behringer and Alesis are not considered "pro" by any actual audio professional.


Hee hee, I knew that would getcha! Behringer, Alesis, Phonic and the like are indeed pro audio gear because the great bulk of their product lines are nothing that a home audio consumer would ever have a need for. That said, I think it’s fair to call them “cheap” or “low end” pro audio, the same thing to a guy like you that HTIB’s are to most of the members of this Forum.




> QSC is real pro gear. JBL has a real pro line.


C’mon, I know you know that even stellar brands like QSC and Crown have had some “stinkers” in their product lines from time to time. I think I read somewhere recently that Crest ultimately fell on hard times because at some point their quality went down (as you probably know, Peavey owns them now). Most of these “high end” amp brands are now selling stuff as cheap (price-wise) as Behringer. (Not that I think anyone would ever confuse those amps with anything tour-worthy – not anyone who knows anything about it at least.)




> I'll respond to others in PM in a now lame attempt to say out of this thread.


Please don’t do that - stay out of the thread I mean. You’re giving a lot of people an education. :T

Regards, 
Wayne


----------



## Wayne A. Pflughaupt

xtinkshun said:


> You said Behringer is NOT a PRO amp. Why? Which brands are considered PRO amps and what makes them pro amps compared to other companies.


You have to keep in mind that when a guy like gazoink talks about what he considers "real" pro gear, he mainly means the heavy-duty equipment that is suitable for touring sound reinforcement systems. This stuff is schlepped across the country in eighteen-wheelers, dropped off the backs of trailers (oops!), often has to operate all day outdoors in humid, 95-degree summers, etc. This is the life this equipment lives day after day, month after month, year after year, what they typically call “road-worthy” gear in the industry that makes or breaks not only the reputation of the manufacturer, but the sound company that relies on it as well. Naturally this gear is a significant cut above the stuff that might be permanently and safely installed in an air-conditioned club, or that we might highjack for use in a home theater.




> Is it the price? if QSC amp cost $800 then will it sound better than Crown and Behringer? Im curious as it relates to facts.


 For the most part watts are watts and amps sound the same (although in isolated instances I have heard pro audio gear in my system that noticeably degraded the sound - not the kind that gazoink would call "pro audio" though" - LOL). Mainly what you’re getting with a higher-priced amp is better build quality. Up to a certain point that matters for home users (for instance you don’t want one so cheap that the switch breaks in the first month of use, or a binding post breaks the first time you give it a serious crank), but at some point what you’re paying extra for is that heavy-duty aspect: a heavy-gauge steel chassis, over-sized heat sinks, the ability to play 16 hours a day for years on end (like would be the case for something in a restaurant), the ability to endure sustained transportable use, etc.




> I assume amps like Parasound, Krell, etc are purchased for their names more than sound quality which makes me wonder IF I walked into my Hi-Fi dealer carrying a Crown X 1000 fridged @ 600watts WILL is sound identical to the McIntosh MC601 monoblock? If not WHY? They are both 600 watts @ 8 ohms.


That’s a little harder to answer. People who buy stuff like Krell and Mac claim they can hear differences in amplifiers. Personally I’ve only heard differences in decidedly low-end gear, but not anything of decent quality, even the lower product lines of the popular manufacturers. Your mileage may vary.

Regards, 
Wayne


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## xtinkshun

> For the most part watts are watts and amps sound the same (although in isolated instances I have heard pro audio gear in my system that noticeably degraded the sound - not the kind that gazoink would call "pro audio" though" - LOL). Mainly what you’re getting with a higher-priced amp is better build quality. Up to a certain point that matters for home users (for instance you don’t want one so cheap that the switch breaks in the first month of use, or a binding post breaks the first time you give it a serious crank), but at some point what you’re paying extra for is that heavy-duty aspect: a heavy-gauge steel chassis, over-sized heat sinks, the ability to play 16 hours a day for years on end (like would be the case for something in a restaurant), the ability to endure sustained transportable use, etc.
> 
> Regards,
> Wayne


I think his has been a very helpful and educational thread. I borrowed my sister parasound HCA 1200 (which I sold her with a pair of Mirage M3si) Awesome speaker but not very efficient. 

So I am wondering if I connect the Parasound 200wpc if it will sound the same as my Crown X1000 200wpc?
I did notice gain knobs on the rear of the Parasound. Since this was back in 1990 or so were they still using p
ro amp circuitry inside commercial amps? Sorta bridging the 2 technologies or converting. Some of these commercial amps weigh up to 100lbs. Im not saying if it weighs more it will last longer, I assume the weight is due to the case and power supply. 

For my test I could connect them to the Mirage M3 Impedance: 6 ohms nominal, 4 ohms minimum. Sensitivity: 83dB at 2.83V 
and on the opposite end a pair of DIY Tempest 8 ohms 98db - 2.83V/1m
I'll try to keep the volume and spl as close as possible via an spl meter. I wonder If I will hear a noticeable difference between the two or if they will sound the same... 
I could throw in a cheap Denon 1913 @ 125 wpc and/or use the Parasound pre-amp I sold with the Parasound amp. Curious of the outcome....


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## Mikeydude

Hi,
I am new to the forum and noticed this thread, I am a professional live sound engineer and wanted to clarify the question of why pro audio systems use bi-amping.

Well, firstly tri-amping is common in a big system with b-amping being used just on stage monitoring.

It is done for the following reasons...

It allows better control (i.e it is much easier to control the system if you are manipulating the signal side as opposed to the power side after the amplifier)
It allows each frequency range to be processed individually with the advantage that...

The amplifier power can be matched to the speakers (i.e big amps for bass smaller amps for mid and tops). This means there is less chance of damaging the smaller power handling higher frequency transducers in the system.
The electronic crossovers can be altered at the touch of a button, and they can have much steeper roll offs than passive crossovers.
Each frequency range can be dynamically controlled with limiters, this better protects the speakers from overload that an overall limiter and if it occurs the compression "pumps less" so it is less noticeable to the audience.
The speaker processing system (which is the fancy name for modern digital crossovers) also allows for phase and delay corrections.
It is also important to be able to control the gain of each frequency band, this is impossible with passive crossovers.
Many passive crossovers don't remove the high frequencies from being fed to the low frequency transducers, this can overheat the low frequency transducers and give the impression that they are handling less power.

active crossover systems (bi amping ,tri amping etc) just sounds better and clearer in pro audio, but I guess it probably also adds distortion by adding phase issues etc....but these subtle disadvantages are insignificant compared to the advantages!!!!


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