Fundamental frequency VS real world amplification

[fdeck]

So driver power compression does not exist?

Not to mention, an inch of driver excursion.

 

[knuckle_head]

Right. The midbass freqs make you feel like gettin' it on, and the sub-bass freqs make you sterile.

See? I'm learning!

.....that there is funny!

 

[Rick Auricchio]

If you reproduce the entire signal from any instrument, and then filter out the fundamental, you will STILL HEAR IT.

Right, as long as the second harmonic is present. Typically the tube/transformer processing in a studio helps enhance that harmonic.

This is how virtually all recordings end up sounding good, even on speakers that obviously can't reproduce the fundamental: bookshelf systems, boom boxes, even many cars.

 

[dhomer]

Several years back I tried to cover the B-string fundamental by designing and building an 18" sub with a -3dB of 27Hz. Onstage this setup (under a 4-10) caused more issues than benefits. Sure, 30 feet into the room folks were feeling it. That rig reproduced subsonic so well, every time I touched the strings the speaker cones wanted to jump out of the cabs. My amp (DCM600 bridged) had all it could do controlling the wide excursions, much less try to consistently deliver a tone. It also raised a lot of hell with the PA setup.. The solution was to put a 35Hz highpass filter in the preamp effects loop. That in itself told me chasing the fundamental was not worth it. Eventually I went back to my original 2-12 rig..

 

[Jeff Permanian]

Yeah, the equipment is there.

Take a look at this...

[Invalid or Expired Link Removed]

It weighs 149 lbs, 1000 watts recommended and it is + / - 3db all the way does to 12hz. This ought to get ANY fundamental frequency of any bass guitar.

This company is known for publishing specs that are real........no bogus specs that serve no purpose beyond marketing.

What do you think?

I'm actually about to introduce an all new Captivator that is half the size, half the cost, same output.
15-85hz +/-3db
86db at 1 watt, 1 meter
4 ohm normal impedance
98 lbs
1000 watt amplifier recommended
30" x 20" 22.5" (same size as the Growler)
MSRP $999

 

[4Mal]

That bucket holds a certain amount of water. But recorded bass guitar is often quite a bit different than live venue bass guitar - even when comparing the same bassist in the same time frame.

Obviously then, the ecomomies and tradeoffs of playback enclosures for home (and studio) have allowed the lowest octave of LF content to be treated differently in the mix when it becomes more practical, and people seem to like that.

No doubt about it. If you isolate the sound if the bass on a recorded track as best you can it's often not a real workable or perhaps listenable tone on it's own. Some producer got busier with his filter set and made it fit ... you know the mix it on NS-10's, then play it back in the car, then try it on the KEF's or B&W's last approach ... and then of course, even though Mr Big Name Bassist is up on the Big Venue stage - he's still subect to most of the same physical space issues that we would be ... If 60 hz is going to boom for me, likely it will for _____ too. Of course ____ probably has a real sound guy out front to deal with it ... whereas I have me ...

 

[alexclaber]

Several years back I tried to cover the B-string fundamental by designing and building an 18" sub with a -3dB of 27Hz. Onstage this setup (under a 4-10) caused more issues than benefits. Sure, 30 feet into the room folks were feeling it. That rig reproduced subsonic so well, every time I touched the strings the speaker cones wanted to jump out of the cabs. My amp (DCM600 bridged) had all it could do controlling the wide excursions, much less try to consistently deliver a tone. It also raised a lot of hell with the PA setup.. The solution was to put a 35Hz highpass filter in the preamp effects loop. That in itself told me chasing the fundamental was not worth it. Eventually I went back to my original 2-12 rig..

I bet if you'd had four of those 18" subs and just as many amps then it would have worked surprisingly well!

Alex

 

[Jeff Permanian]

So driver power compression does not exist?

I still have never posted power handling specs on any of the products. Power handling specs leave room for interpretation. How many countless threads are there out there about what size amplifier should I use with what speaker?

The reason why there are so many questions is because you need a lot more information than just rated power handling and normal impedance to properly choice an amplifier .

I make it easy on people, save them math and they get a reliable speaker system.

 

[greenboy]

No doubt about it. If you isolate the sound if the bass on a recorded track as best you can it's often not a real workable or perhaps listenable tone on it's own. {...}

Well, that's true in either a good live mix or a recorded mix, SOMETIMES. And sometimes not. Depends on arrangements, layering, musical genre/concept, etc.

More what I was referring to is that a lot of recorded bass guitar has more content in the lowest octave. It may even be augmented by subtle use of subharmonizer in recent years. And for any period of recorded music, even if no EQ boost in the LF is being used much, just the fact that DI is often part of the sound ensures that live enclosures are not subtracting/filtering LF content. As long as the mid/upper-bass and midrange hasn't been pulled back too far, such mixes work on the tiniest radios to the largest extended-LF subwoofer-augmented home systems, and can sound progressively more awesome as the playback system is upgraded.

But in live music, the bass guitar backline and the sound reinforcment facilities, and the environment itself - often limit what is tonally practical, and some of that is tradeoff for SPL. That bottom octave is attenuated or even non-existant compared to the good recording of the same bass and bassist. It can still sound rich and full, live, but not as rich and full as when one gets to hear well-crafted recordings on a decent system.

 

[greenboy]

I still have never posted power handling specs on any of the products.

Uh, did you read my posts on your top SPL "Useable Output" figures? Those very much imply both power handling - and an obvious projected figure, since there is not any loss from power compression in that figure, which is a physical given.

Anyway. If you choose not to understand that, I'll still add this:

If you are indeed designing for SR (and are looking at bass guitar applications as well), then 15 Hz or 12 Hz is totally useless. And it comes at the expense of bulk and weight - and SPL where it is truly needed. It seems to me that even if your subs are doing 12 or 15 Hz within a +-3 aperture that they are not SR/MI products, though they may be great for specific fixed installations. Bump that f3 up an octave or so in another design and you'd have something a little closer to what is needed for those who desire parity for low fundamentals for low-tuned/extended range basses and other sources like synths, in a live setting.

 

[Jeff Permanian]

Uh, did you read my posts on your top SPL "Useable Output" figures? Those very much imply both power handling - and an obvious projected figure, since there is not any loss from power compression in that figure, which is a physical given.

An amplifier's RMS rating is an average and an amplifier will produce twice its rated RMS power when reproducing a square wave.

Other company power handling specs are based on 3 db (or more) of power compression however my amplifier recommendations are based on less than that.

If you are indeed designing for SR (and are looking at bass guitar applications as well), then 15 Hz or 12 Hz is totally useless. And it comes at the expense of bulk and weight - and SPL where it is truly needed. It seems to me that even if your subs are doing 12 or 15 Hz within a +-3 aperture that they are not SR/MI products, though they may be great for specific fixed installations. Bump that f3 up an octave or so in another design and you'd have something a little closer to what is needed for those who desire parity for low fundamentals for low-tuned/extended range basses and other sources like synths, in a live setting.

The Captivator is listed under "Installation Products" and its discription reads "The Captivator is designed for Install applications needing ultra low bass extension (professional cinema, pipe organ reproduction, special effects, theme parks).".

 

[greenboy]

Right here ([Invalid or Expired Link Removed]) it says:

Frequency +/-3db 12-70hz
Sensitivity* 86db
Useable Output ** 116db
Recommended Amplification up to 1000 watts

** Obtainable output with maximum recommended amplification


So regardless of an amp's ability to produce beyond continuous ratings, this copy sure implies 1000 watts. And of course with most tecnologies there is going to be at least 3-6 dB of driver compression when you are making that much heat.

Are you doing a servodrive? Just curious.

I probably could have been more clear later; I realize that you yourself recommend as an home theater or an installation product, but the poster who linked your site initally implied that it was a topically relevant. And in a way it is. My suggestions were merely on what it would take to focus on a more "SR+" (low-tuned fundamentals at parity) product.

Anyway, your stuff looks well designed and interesting. Don't let my sceptical and questioning techie side make you believe any less ; }