Amplifier function - cut low frequencies from the stereo speaker outputs only

[Doodski]

Many powered subs also have speaker level inputs which incorporate an inbuilt HPF (in the form of a large BP electrolytic cap) on the speaker level in/out terminals.

What kind of value of cap would they use?

 

[Robin L]

I got an Onkyo AVR, 7.1, used in a 5.1 arrangement. It had plenty of control over the stereo [main] speakers EQ, mated that system to multiple subs to good effect. I think you really want an AVR set up as a 2.1 stereo.

 

[restorer-john]

What kind of value of cap would they use?

150uF and up. 220uF I've seen. Somewhere on ASR, I swear I took a pic. Here it is:

BP 150uF/100WV. That'd give approx -3dB@130Hz on an 8R driver.

 

[Doodski]

150uF and up. 220uF I've seen. Somewhere on ASR, I swear I took a pic. Here it is:

BP 150uF/100WV. That'd give approx -3dB@130Hz on an 8R driver.

That makes it good for up to ~625Wrms @ 12.5Apeak. That's generous. I don't see those caps failing anytime soon if quality caps.

 

[restorer-john]

I don't see those caps failing anytime soon if quality caps.

Pretty much wun hung lo brand, but good enough I guess. The glue will hold them together. LOL.

 

[Doodski]

Pretty much wun hung lo brand, but good enough I guess. The glue will hold them together. LOL.

I haven't worked on many subwoofers and most of them that I did had a IC for output; the easy stuff. I worked on a couple of Velodyne and thankfully they never had a servo issue because I was flying without a service manual.

 

[sarumbear]

Of course you can augment the bottom end of loudspeakers with a powered subwoofer. Many powered subs also have speaker level inputs which incorporate an inbuilt HPF (in the form of a large BP electrolytic cap) on the speaker level in/out terminals.

Et to Brute!

I thought you would understand how a crossover works and what havoc your suggested set-up will create to FR.

A sealed enclosure speaker is a 2nd order HP filter at its f3. Similarly a vented enclosure speaker is a 4th order HP at its f3. When you put a capacitor in series you will cascade a 1st order HP filter, creating a 3rd (closed) or 5th (vented) order HP filter. This is physics.

Now shouldn't we ask those manufacturers: how do you know my speaker type or f3 that a fixed capacitor is used and why there is no setting for sealed or vented enclosures?

Manufacturers do things that has no engineering sense. I believe ASR tries to do stop them. We should help the cause as much as possible and question them.

 

[restorer-john]

Et to Brute!

I thought you would understand how a crossover works and what havoc your suggested set-up will create to FR.

A sealed enclosure speaker is a 2nd order HP filter at its f3. Similarly a vented enclosure speaker is a 4th order HP at its f3. When you put a capacitor in series you will cascade a 1st order HP filter, creating a 3rd (closed) or 5th (vented) order HP filter. This is physics.

Now shouldn't we ask those manufacturers: how do you know my speaker type or f3 that a fixed capacitor is used and why there is no setting for sealed or vented enclosures?

Manufacturers do things that has no engineering sense. I believe ASR tries to do stop them. We should help the cause as much as possible and question them.

What on earth are you talking about?

Powered subwoofer manufacturers have recognized this forever. They roll off the mains, offer frequency, level and variable phase (polarity in some cases) control of the sub. What more do you want? A naked woman delivering champagne? (that's be nice for sure)

It's not rocket science and never will be.

 

[sarumbear]

What on earth are you talking about?

I though I explained using engineering terms. I agree that it is not rocket science but how speakers behave is science.

 

[diddley]

What about the lady delivers a subwoofer, nicely dressed ofcourse.

 

[restorer-john]

What about the lady delivers a subwoofer, nicely dressed ofcourse.

Long throw subwoofer with a very high power handling of course.

 

[eddantes]

Parasound has you covered. Or just use a MiniDSP...

 

[restorer-john]

I though I explained using engineering terms. I agree that it is not rocket science but how speakers behave is science.

Tell me about your powered/unpowered slugwoogers to compliment those mini monitors? What was so groundbreaking? Genuinely interested...

 

[sarumbear]

Tell me about your powered/unpowered slugwoogers to compliment those mini monitors? What was so groundbreaking? Genuinely interested...

If you are genuinely interested you may want to re-read my post and ask specific point you disagree on. Meanwhile, I have not defined the size of any speaker, as it’s irrelevant to a crossover.

 

[DonH56]

Isn't the crossover to the sub set well above the innate roll-off in most installations? I am not sure how f3 plays into the crossover from mains to subs; the crossover should be an octave or two above the HPF filter function of the sub's low end response. Unless trying to mix ported and sealed subs (blah) I have rarely worried about the subs low-end rolloff, focusing instead upon the crossover to the main speakers. The usual trick is to align phase at the crossover frequency for subs and mains, which a standard L-R circuit does nicely.

 

[sarumbear]

Isn't the crossover to the sub set well above the innate roll-off in most installations? I am not sure how f3 plays into the crossover from mains to subs; the crossover should be an octave or two above the HPF filter function of the sub's low end response. Unless trying to mix ported and sealed subs (blah) I have rarely worried about the subs low-end rolloff, focusing instead upon the crossover to the main speakers. The usual trick is to align phase at the crossover frequency for subs and mains, which a standard L-R circuit does nicely.

A cross-over as the the name suggest is a combination of cross between a LP and a HP filter. Both filters must have the same frequency in order for a cross-over to work. Here is a layman explanation.

To add to the above every speaker driver is a LP filter. Sealed enclosures have 2nd order (12dB/oct) and vented ones have 4th order (24dB/oct) responses at f3, the cut-off frequency of the filter. A stand mounted speaker mostly have a f3 around 60-80Hz. That is very near to the subwoofer frequencies used with subwoofers. This makes subwoofer matching not a trivial job.

Naturally, you can just ad a sub to your speakers and get more bass. That doesn't mean it is correct. Then again I assume anyone on this forum is searching for the correct solution?

 

[sarumbear]

View attachment 217925
Parasound has you covered.

Far too expensive!

Or just use a MiniDSP...

Not an integrated amplifier.

 

[eddantes]

Far too expensive!


Not an integrated amplifier.

SHD Power

Roon Ready streaming amplifier with Dirac Live® room correction, 2 x 120Wrms power amplifier, miniDSP audio toolbox for subwoofer integration, Volumio music player, 450MHz Sharc DSP processor

www.minidsp.com

 

[sarumbear]

SHD Power

Roon Ready streaming amplifier with Dirac Live® room correction, 2 x 120Wrms power amplifier, miniDSP audio toolbox for subwoofer integration, Volumio music player, 450MHz Sharc DSP processor

www.minidsp.com

I apologise, I guess it is an integrated amplifier but without any analogue input its use is limited. However, that is becoming less of an issue as the time progresses.

 

[djtetei]

Any integrated amplifier with a built-in crossover, but without delay adjustment, no matter how much it costs, is pretty much useless, because it forces you to place the subwoofers in the same plane with the main speakers, which may not be the optimum placement for subwoofers in a certain room configuration.
So, give a well made and specifically designed speaker management system / active crossover, and I will choose it anytime against any amplifier with so called "subwoofer support".