Energy Transfer Question - Crossover and Amp - Vertical Biamping

[12Many]

So I am struggling to understand something in the the context of passive vertical biamping to a speaker with two sets of binding posts in relation to the speakers internal crossover. The power output of the amp is determined by the volume control since the speakers seem to be a predefined resistance / impedance, even thought that impedance does change with frequency. In this discussion, passive vertically biamping provides the full spectrum signal to both the woofer posts and the mid/tweeter posts on the speaker, so it seems like not much benefit because both channels of the amp are still amplifying the full spectrum signal. However, I read an article (that I can not now find) that suggested that because the crossover blocks a portion (frequency specific) of the signal from the driver, each channel of the amp does not see or experience the full load of the speaker.

In the specific instance of one channel of the stereo amp being connected solely to the mid/tweeter posts of the speaker, what happens to the low frequency energy that is in the output of that channel of the amp. I understand that it is 'blocked' from the actual driver by the crossover, likely by a capacitor or some RC network. Because the low frequency signal components, in particular current, do not make it to the driver, does that channel of the amp not experience the same current demands or draw as if it were driving the full speaker, even though that channel of the amp is receiving and amplifying the full spectrum signal? Or, is the current simply shunted to ground? We know if nothing is connected to the amp, the amp provides a voltage on its output, but there is no current flow. In this case, the crossover is connected to the amp. My question is technical, and not focused on what a listener can hear or not hear.

Hopefully I have phrased my question clearly and not muddled it up too much. Does anyone have any thoughts on this? Thanks.

 

[DVDdoug]

I've never heard of it. (Thanks for explaining it!)

But your intuition is correct. If both sets of terminals are getting the same signal it doesn't matter if the signals come from one amplifier or two different amplifiers.

 

[SSS]

So I am struggling to understand something in the the context of passive vertical biamping to a speaker with two sets of binding posts in relation to the speakers internal crossover. The power output of the amp is determined by the volume control since the speakers seem to be a predefined resistance / impedance, even thought that impedance does change with frequency. In this discussion, passive vertically biamping provides the full spectrum signal to both the woofer posts and the mid/tweeter posts on the speaker, so it seems like not much benefit because both channels of the amp are still amplifying the full spectrum signal. However, I read an article (that I can not now find) that suggested that because the crossover blocks a portion (frequency specific) of the signal from the driver, each channel of the amp does not see or experience the full load of the speaker.

In the specific instance of one channel of the stereo amp being connected solely to the mid/tweeter posts of the speaker, what happens to the low frequency energy that is in the output of that channel of the amp. I understand that it is 'blocked' from the actual driver by the crossover, likely by a capacitor or some RC network. Because the low frequency signal components, in particular current, do not make it to the driver, does that channel of the amp not experience the same current demands or draw as if it were driving the full speaker, even though that channel of the amp is receiving and amplifying the full spectrum signal? Or, is the current simply shunted to ground? We know if nothing is connected to the amp, the amp provides a voltage on its output, but there is no current flow. In this case, the crossover is connected to the amp. My question is technical, and not focused on what a listener can hear or not hear.

Hopefully I have phrased my question clearly and not muddled it up too much. Does anyone have any thoughts on this? Thanks.

The binding posts are such that one pair feeds the low-frequency section (basically the woofer). The other pair (both pairs NOT connected) feeds middle and treble chassis. There the internal crossover divides between mid and treble. You are right, even when an amplfier provides the full range signal as output voltage only the power (current) need is drawn from the amp, in the latter case only for mid and high frequencies. Since this amp is not loaded with the bass content current it may operate better with lower distortion. Most power is needed for the woofer. Of course for stereo 4 power amps are needed.

 

[Speedskater]

Actually the amplifier outputs a voltage gain (often 26 or 28dB) of the input signal. The output current and power depends on the load impedance at that frequency. So the tweeter section has a very high impedance at woofer frequencies so very little current & power is output from the tweeter amp at woofer frequencies. And vice-versa.

 

[DonH56]

Bi-amping: https://www.audiosciencereview.com/forum/index.php?threads/bi-amping-101.22817/

 

[12Many]

Thanks everyone. Super helpful.

 

[Chrispy]

Curious, you just have extra amps lying around and want to put them to use with the passive bi-amping thing?

 

[12Many]

Curious, you just have extra amps lying around and want to put them to use with the passive bi-amping thing?

No. Mostly I did not understand what happened to the signal. I knew the amp was amplifying the full band signal, but I also knew the low frequency energy was not hitting mid/tweeter driver. Did not fully understand what was occurring. For a number of reasons, I do like the idea of biamping and might try/buy a second amp. I enjoy changing things around and listening for differences. And, if I can make my system sound better within my budget, that is valuable to me.

 

[Chrispy]

No. Mostly I did not understand what happened to the signal. I knew the amp was amplifying the full band signal, but I also knew the low frequency energy was not hitting mid/tweeter driver. Did not fully understand what was occurring. For a number of reasons, I do like the idea of biamping and might try/buy a second amp. I enjoy changing things around and listening for differences. And, if I can make my system sound better within my budget, that is valuable to me.

I'd just get/use a more powerful amp rather than spend extra on extra amp boxes. The differences in amp draw are fairly miniscule due the passive crossover....more a theoretical advantage than particularly audible.

 

[Cbdb2]

If your current Amp is not clipping you probably won't hear a difference.

 

[Doodski]

@12Many I realize this thread is dated now but have you considered a active crossover and removing the passive crossovers from the signal path?

 

[12Many]

@12Many I realize this thread is dated now but have you considered a active crossover and removing the passive crossovers from the signal path?

I have considered it but I don't want to mess with my speakers and the crossover is in the speaker.

 

[Doodski]

I have considered it but I don't want to mess with my speakers and the crossover is in the speaker.

Ahhhh... OK... Well... Are you using PEQ for equalization?

 

[12Many]

Ahhhh... OK... Well... Are you using PEQ for equalization?

No - I have a basic system. Streamer to DAC (with built in volume control) to amp to speakers.

 

[Doodski]

No - I have a basic system. Streamer to DAC (with built in volume control) to amp to speakers.

Well... Not to change your thread topic but I operate the EQ/PEQ webpage here @ ASR and if I may suggest a major improvement of PEQ.

EQ Software for Windows, Linux, macOS, iOS/iPadOS and Android.

Any suggestions are welcome. Post suggestions here. I will gather the details and add them. Thanks. :D This will be organized as results come in. @sweetchaos made a guide for PEQ filter data input and operation. For crossover software go here. Windows: AutoEQ four easy steps to make your...

www.audiosciencereview.com

 

[12Many]

Thanks. Wow - that is a lot of info. Maybe someday I will go in that direction.

 

[Doodski]

Thanks. Wow - that is a lot of info. Maybe someday I will go in that direction.

Anytime you want to get into PEQ let me know your needs and I'll recommend some stuff that is nice.

 

[RayDunzl]

Two way speaker nominal impedance:

In my case, the speaker is rated as 4 ohms, and measures 4 ohms with a Volt/Ohmmeter..

If the shorting straps are removed, the Ohmmeter reads about 8 ohms on either the woofer or tweeter posts.

Based on that observation I concluded the "crossover" isn't crossing anything.

The woofer has a low pass filter, and the tweeter a completely separate high pass filter.

Later I found a schematic for them that confirmed that idea.

 

[kemmler3D]

For a number of reasons, I do like the idea of biamping and might try/buy a second amp. I enjoy changing things around and listening for differences. And, if I can make my system sound better within my budget, that is valuable to me.

Realistically this is only going to make an audible difference if you can already hear amp distortion through your speaker, which is unlikely unless you're currently using a very dinky or flawed amp.

Think of it this way - distortion becomes audible when you get near 100% of your amp's capacity. Before that, it isn't. That's sort of how the amp's capacity is defined.

So if you are currently only using 50% of your amp's capacity, you're going to hear roughly zero distortion, and if you bi-amp, you'll be using 25% capacity of two amps and still hear zero distortion.

Put the money toward better speakers, a sub, or room treatment / correction instead and you are much more likely to make a positive change in what you hear.l