Klipsch Cornwall IV

[Eppie]

OK, but the frequency that's most prominent from a bass is the first harmonic, which is double the frequency of the fundamental, unless you pick/pluck the string at the 12th fret. At that point, the string is acting as a half-wave, rather than a full wave, if viewed on video with incandescent lighting.

True, a bass does not play a pure sine wave, otherwise you would never hear the difference between pickup brands, types of strings, the wood used in the body, etc. I wonder how much of the fundamental makes up the content from a low E? Maybe I'm looking at this the wrong way?

 

[TLS Guy]

I am very tempted to start a separate thread on this as it is topic that I have long been curious about. I play electric bass and also listen to a lot of rock music. The low E string on a bass is 41Hz which is well below the stated +/- 3dB frequency response of most speakers. Many players use 5 string basses now where the low B is 31Hz. Those notes are still audible on bookshelf speakers, but compared to the real thing they sound anemic and lacking "punch" or energy. The same would hold true for the bass string section of an orchestra which also plays down to E (and there are 5 string double basses as well). The low E (41Hz) is a very common note so pretty much all speakers must be able to produce it, albeit at varying levels.

The logical conclusion is that the important factor becomes the slope at which the bass rolls off, or the -6dB and -10dB points, which few manufacturers list. Boundary gain also needs to be taken into account, but that will vary greatly between speaker models and room configurations. My Studio 20's are rated down to 54Hz +/- 2dB and from the graphs on Stereophile look to be -7dB at 40Hz and -14dB at 30Hz. Without subwoofers those low bass notes will never have the same impact as the live instrument. My bass cabinet, for example, uses a 15" Electrovoice driver that has no problems getting down to 30Hz. It's no surprise that the 7" woofer in the Studio 20 can't compete. As Mr Boat would say, you can't beat displacement.

Unless you have true full range speakers, this just reinforces the importance of having properly integrated subs to cover the below 60Hz content. For the "undiscerning" that you mention, I think ignorance is bliss, as they say. You don't miss what you don't know about. Once you have heard a system that reproduces deep bass properly, though, it's hard to go back.

You are correct. If you listen to enough speakers you are short changed of the F3 is above 30 Hz or so. The problem you describe is a serious disturbance of the balance between the fundamental and the harmonics. So in the end this makes the case that a two way speaker plus sub, is actually a three way, and a three way speaker plus sub is actually a four way speaker. This means that speakers and subs need to be designed as a unit and sold together as a unified design. In addition you don't want subs removed from the speakers. I know that is against current wisdom, but it is just plain daft to pepper subs around a room.

 

[Eppie]

You are correct. If you listen to enough speakers you are short changed of the F3 is above 30 Hz or so. The problem you describe is a serious disturbance of the balance between the fundamental and the harmonics. So in the end this makes the case that a two way speaker plus sub, is actually a three way, and a three way speaker plus sub is actually a four way speaker. This means that speakers and subs need to be designed as a unit and sold together as a unified design. In addition you don't want subs removed from the speakers. I know that is against current wisdom, but it is just plain daft to pepper subs around a room.

What is the consequence of moving the subwoofer away from the mains? Given that an 80Hz tone has a wavelength of about 14' the reasoning has been that dealing with room modes was more important. We've certainly seen some very flat bass response curves from members like Pogre. Can the phase adjustment on the subwoofer crossover make up for moving it away from the mains?

 

[highfigh]

True, a bass does not play a pure sine wave, otherwise you would never hear the difference between pickup brands, types of strings, the wood used in the body, etc. I wonder how much of the fundamental makes up the content from a low E? Maybe I'm looking at this the wrong way?

I wasn't referring to the signal from the instrument, it's a physical half or whole wave, on the string. If you pluck the low E on your bass at the 12th fret (position, if it's fretless), watch the string vibrate- it should have a different tone from plucking at any other position (deeper sounding) because the fundamental is stronger. If you want, position (or have someone hold) a digital camera while your lights are on- make sure they're incandescent. You should see the string almost as if it's in stop-action because of the lights flashing at 60Hz.

The video shows this, in a relatively basic way but watching it is very helpful.

 

[highfigh]

What is the consequence of moving the subwoofer away from the mains? Given that an 80Hz tone has a wavelength of about 14' the reasoning has been that dealing with room modes was more important. We've certainly seen some very flat bass response curves from members like Pogre. Can the phase adjustment on the subwoofer crossover make up for moving it away from the mains?

If the phase control does more than just 0° and 180°, it can only help when those coincide with the speaker positions unless you use the speaker distance control in the AVR to electronically 'change' the speaker positions. You would need to use the smallest increments. If you want to see this in real time, fire up REW and make the adjustments to one speaker at a time and watch the frequency response change.

 

[TLS Guy]

What is the consequence of moving the subwoofer away from the mains? Given that an 80Hz tone has a wavelength of about 14' the reasoning has been that dealing with room modes was more important. We've certainly seen some very flat bass response curves from members like Pogre. Can the phase adjustment on the subwoofer crossover make up for moving it away from the mains?

You don't want to separate fundamentals from harmonics. Once you move the sub away from the rest of the speakers you can not get a nice impulse response. Usually you get several spaced in time. That is not good.

The other issue is that if you move the sub, you get more power where it counts. If you cut the sub off at 80 Hz, then that driver and amp can not assist the other drivers in the transition zone. One of the big reasons that my rig really has that solid you are there oomph, is because I am effectively having what are the sub drivers assist up to 400 to 500 Hz range. That is why I don't use sub drivers in my main system. They don't have the bandwidth.

Sigberg have realized this and cut off the mains at 90 to 95 Hz, but if you use their integrated sub, it can assist the main speaker way up. They say often up to 250 Hz. Active designs make all this possible, and the improvement is astonishing. You won't pick this up in standard measurements, but you sure will when you give your system the "gas". The whole body and foundation of a large orchestra is full realized and reproduced. You can throw in a large organ and it will still beg for more.

I am certain that we are now on the threshold of a different philosophy in speaker design. Unless you have really experienced the benefit of active design, plus integrating the whole system it is not possible I suspect, to realize what I'm talking about. Buying a passive speaker and an active sub from a different manufacturer is just not going to cut it going forward. That approach should have been long past its sell by date by now.