How low is low enough?

[highfigh]

Excuse my ignorance but what does "Q" stand for?

Originally, it stood for Quality Factor, but it has been stripped down to Q. In Theil-Small speaker parameters, there's a Qes (electrical Q), a Qms (Mechanical Q) and a Qts (total Q). It has to do with how something resonates, either electrically, mechanically or as a whole. High Q means that it rings out like when you flick a wine glass, and only in a narrow frequency band. Empty, it resonates until the energy is gone or we can't hear it but it's a wider band of frequencies. With liquid, the ringing is dampened, somewhat and the duration decreases, as well as the resonant frequency. Full, it's dampened enough that it really doesn't ring much. Low Qts means that it's highly damped and if the Qts is high, it's like thumping a drum head with no damper. It may hit really hard but the note just keeps on going. This is really bad for music, especially when the bass range has a lot going on. Classical music likes more damping, so you may see some speakers that are designed for that type of music with a Qts of ~.6 and for systems that are designed for Rap and techno, you may see something in the Qts=1.2 range. Along with this high Q spec comes a resonant peak. High Q speakers have a peak before they roll off toward the lowest extremes and lower Q have a smoother response, with little, or no peak. Qts=.707 is called "critically damped" and works well for a lot of different kinds of music.

A large speaker in a small room will cause the Q to raise and a small speaker in a large room will lower it but in that case, it's not the air in the speaker enclosure that's resonating, it's the air in the room.

From Wiki:
http://en.wikipedia.org/wiki/Quality_factor

 

[BWG707]

Originally, it stood for Quality Factor, but it has been stripped down to Q. In Theil-Small speaker parameters, there's a Qes (electrical Q), a Qms (Mechanical Q) and a Qts (total Q). It has to do with how something resonates, either electrically, mechanically or as a whole. High Q means that it rings out like when you flick a wine glass, and only in a narrow frequency band. Empty, it resonates until the energy is gone or we can't hear it but it's a wider band of frequencies. With liquid, the ringing is dampened, somewhat and the duration decreases, as well as the resonant frequency. Full, it's dampened enough that it really doesn't ring much. Low Qts means that it's highly damped and if the Qts is high, it's like thumping a drum head with no damper. It may hit really hard but the note just keeps on going. This is really bad for music, especially when the bass range has a lot going on. Classical music likes more damping, so you may see some speakers that are designed for that type of music with a Qts of ~.6 and for systems that are designed for Rap and techno, you may see something in the Qts=1.2 range. Along with this high Q spec comes a resonant peak. High Q speakers have a peak before they roll off toward the lowest extremes and lower Q have a smoother response, with little, or no peak. Qts=.707 is called "critically damped" and works well for a lot of different kinds of music.

A large speaker in a small room will cause the Q to raise and a small speaker in a large room will lower it but in that case, it's not the air in the speaker enclosure that's resonating, it's the air in the room.

From Wiki:
http://en.wikipedia.org/wiki/Quality_factor

Thanks alot. Before I posted I read Wiki's definition and got the gist of it but your explanation cleared things up. I appreciate your well written definition.

 

[njedpx3]

Isiberian give good advice

Chasing the low note is a bad idea in my mind. How often is the lowest note actually even played. 40hz is plenty of extension for most music. Which means almost any well constructed sub will meet your need.

I agree some very good sub brands are SVS and Hsu. If you want a lower cost sub then the Dayton SUB-120Ht for $155 from Parts Express.
http://www.partexpress.com/pe/showdetl.cfm?Partnumber=300-635

 

[highfigh]

Thanks alot. Before I posted I read Wiki's definition and got the gist of it but your explanation cleared things up. I appreciate your well written definition.

I did car audio for a long time and at the last place, we used Term Pro software for box and crossover design. With the kinds of systems we did, along with the number of systems we did, it was really easy to hear a wide variety of box designs, and when we had time (not often), we would make a spare box or two, which would be for the same driver. That way, we could try it and use the RTA and listening tests to find out which we preferred. We had many consecutive weeks where we built at least one box per day and sometimes we each built one, which usually meant 3-5 boxes in one day. It also meant that we could intuitively come up with a rough idea of the response from one type of box, or another, just because of the repetition. It was a great way to hear what one driver in different boxes sounded like, and how the Q affected the sound.

 

[fredk]

I had a pair of ElectroVoice 30W woofers. Does that count?

Um, yup? Damn those would look impressive!

 

[highfigh]

Um, yup? Damn those would look impressive!

Check this link out:
http://www.dougronald.com/sound_images.htm

 

[BWG707]

Check this link out:
http://www.dougronald.com/sound_images.htm

All I can utter is WOW!

 

[sparky77]

All I can say is if your looking to match the output of a pipe organ, it'll never happen unless you have the worlds largest transmission line in your listening area. Otherwise, look at the svs subs, or the hsu's with turbo. Unless you have the space to build a bandpass subhorn tuned to 6hz runing at least 20 maelstrom 21's.

 

[basspig]

All I can say is if your looking to match the output of a pipe organ, it'll never happen unless you have the worlds largest transmission line in your listening area. Otherwise, look at the svs subs, or the hsu's with turbo. Unless you have the space to build a bandpass subhorn tuned to 6hz runing at least 20 maelstrom 21's.

I would amend that to say "it will never happen with CONVENTIONAL home hi-fi loudspeakers.

I've been listening to recorded pipe organ for decades. Whenever I go to hear one live, it's always a huge letdown.

Modern electronic systems are increasingly being used in houses of worship and many of them equal the real thing these days.

A few years back, touring the internals of a large organ (32' stops), the crew from NPR noticed a large loudspeaker. When asked, the music director explained it was there to electronically augment the lowest pedal notes, to give them more oomph (fundamental). When you see a pipe organ, it isn't always pipes that you're hearing.

I was at the Cathedral of St. Joseph's in Hartford, CT, the Austin organ that Berj Zamkochian himself once played, to take a tour and discuss making a recording of works for a commercial release. The music director at that time talked about how when they play the instrument loudly, the stained glass windows would rattle. So naturally, I was expecting something truly impressive. Then he sat down at the console and gave me a blast of full organ. My first impression was "when is he going to give me the full output? Is that all there is?". I was standing on the second level, right next to the pipes. And yes, that was it. And it was then that I realized I'd been listening to pipe organ with too much low frequency energy and at way too loud volume levels.

When you consider the tremendous room gain in a stone cathedral, it becomes even more apparent that the organ isn't itself putting out that much sound pressure.

Folks who think the mighty pipe organ is the unbeatable source for low frequency energy need to experience some up-to-date low frequency reproducers, not stuff made in the 1970s.

 

[fredk]

Folks who think the mighty pipe organ is the unbeatable source for low frequency energy need to experience some up-to-date low frequency reproducers, not stuff made in the 1970s.

Which goes back to my point that you don't need the be-all and end-all of low frequency reproduction to enjoy pipe organ music. Good reproduction down to 20Hz. will get you most of the way there.

 

[3db]

I've been listening to recorded pipe organ for decades. Whenever I go to hear one live, it's always a huge letdown.

Modern electronic systems are increasingly being used in houses of worship and many of them equal the real thing these days.

A few years back, touring the internals of a large organ (32' stops), the crew from NPR noticed a large loudspeaker. When asked, the music director explained it was there to electronically augment the lowest pedal notes, to give them more oomph (fundamental). When you see a pipe organ, it isn't always pipes that you're hearing.



When you consider the tremendous room gain in a stone cathedral, it becomes even more apparent that the organ isn't itself putting out that much sound pressure.

Folks who think the mighty pipe organ is the unbeatable source for low frequency energy need to experience some up-to-date low frequency reproducers, not stuff made in the 1970s.

I've heard some pipe organs play while touring Germany and I can honestly say that I was very impresssed with their sound. I's prefer it to the rap type bass that's coming out of speakers/amplifiers anyday.

 

[basspig]

Which goes back to my point that you don't need the be-all and end-all of low frequency reproduction to enjoy pipe organ music. Good reproduction down to 20Hz. will get you most of the way there.

There are two different statements going on here:

We agree that the pipe organ isn't the be all end all of low frequencies. It can be bested by the new subwoofer technology that emerged in the last few years.

You said that good repro down to 20Hz will get you most of the way there.


To which I state: good reproduction to 16Hz will get you most of the way there. You still need to achieve the SPL of a pipe organ, not just at background levels, but at full organ levels. Nothing less than a pair of Wilson X-S subs are the order of the day here for garanteed reproduction with headroom to spare.

In this day and age, most high end hi-fi systems are still struggling with matching an orchestral crescendo of 105dB without significant compression and some distortion. Pipe organ is still a ways off for that class of system without some serious subwoofer technology. It's out there, and it's capable of insane levels, but a lot of it is in the realm of DiY projects because the commercial demand is so niche market that no one would mass manufacture such a woofer. Most people live in neighborhoods of wood frame houses, or in apartments, where bass output like that is impracticle.

 

[highfigh]

All I can utter is WOW!

I like the shot of his wife or GF standing near them. Gives a real sense of their scale. I really miss the ones I had. I just couldn't think of a way to keep them here, with the stairs I have going to the basement. I made good money on them but there's almost zero chance of finding another pair in cabinets for anything close to what I paid. My uncle built his speakers from mis-matched components and did all kinds of analysis to get the most out of them, in the '50s. He made the cabinets and filled the jacket with sand to deaden them. He built a receiver from a kit and when the kids came, he decided that at some point, they'd be using it, so he dialed it down so they wouldn't smoke anything. The volume control could be turned up all the way and it still wouldn't clip. I told him about my woofers and his eyes glazed, then I think he started drooling.

 

[fredk]

To which I state: good reproduction to 16Hz will get you most of the way there.

I think you and I have a different definition of 'most of the way there'. I have not had a lot of opportunity to listen to the real thing so maybe its difficult for me to judge most of the way there.

Pipe organ is still a ways off for that class of system without some serious subwoofer technology. It's out there, and it's capable of insane levels, but a lot of it is in the realm of DiY projects because the commercial demand is so niche

In a way thats true, but in the last year, there have been a number of subs released that are capable of reaching into the low teens. There are also many subs that will play down to 20Hz clean and with headroom. Sure, there's still junk out there, but if you are careful, you can get a lot out of commercial offerings.

In this day and age, most high end hi-fi systems are still struggling with matching an orchestral crescendo of 105dB without significant compression

Thats a whole other discussion, but I think we are a lot closer to affordable systems with true high fidelity than we were in the mid '70s. My mains have no trouble staying clean even at high volumes and with the full dynamic range of classical music and I didn't spend all that much more, in real dollars, than I did on my first Advent speakers. I'm amazed at how affordable the entry level of 'audiophile' has become.

Now I'm curious to see what sort of levels I am hitting with the lower notes in pipe organ music. Last time I measured, I was hitting 110db peaks on the higher notes. I don't know how accurate my ratshack spl meter is with out a calibration file though.

 

[basspig]

I'm sure we're referencing against vastly different definitions.

There's a lot more to organ music than what your ears hear. Using REW software on headphones and doing a sweep, my hearing pretty much drops off to zilch below 50Hz. I can barely discern 20Hz without using loudspeakers. It's the body that senses so much of the lower frequencies and our brains automatically merge the data into an auditory experience.

So much of the musical experience is FELT more so than heard. That's the primary difference I experience between audio systems in showrooms and the real thing, or what I reproduce here.

Cheap/affordable audio gear has improved immensely since the 1970s. I still have a $700 Sansui rack system, 45W/ch with 10" 2-way speakers upstairs in the livingroom that my wife still uses. I bought it in 1977. Today's $200 systems equal or better it. Back in '73, a $100 stereo had the components of a $29 portable radio for the output stage. Today, they might produce an honest 20W of output.

 

[sturgl]

I don't know how accurate my ratshack spl meter is with out a calibration file though.

SVS has a nice paper on ratshack spl meter calibration:
http://www.svsound.com/questions-faqs-rscomp.cfm