Subwoofing without subs

[NorthSky]

Not cars Frank, threads.

 

[Thomas savage]

Well if you don't get out much and have plenty of time on your hands (just like me lol) might as well go subbing... It's not like anyone will force you to keep them in the system if you don't like the result.

 

[Cosmik]

What about the phase? Is your system getting the phase and timing right? If everything 'lines up' isn't that going to be more important than the absolute level of subsonic frequencies? Phase correcting the bass implies large FIR filters and higher latency presumably..? For example, the Kii Three in normal operation has 90ms latency, but also has a low latency mode for real time monitoring.

The overall soundquality is not as perfect in low latency mode as it is in normal mode (most notably only in the low end), but still provides a very pleasurable listening experience for your TV.

 

[RayDunzl]

What about the phase?

As shown in post #7, there is a phase anomaly around 48 Hz where the waves from woofers (and subs, if in use) go out of phase at the listening/measuring position, I think, due to the asymmetry of the room toin the left rear corner (there is no left rear corner). Although AcourateDRC (lite version) does some phase correction, it seems to ignore this problem. I'll send a message to the author.

Is your system getting the phase and timing right? If everything 'lines up' isn't that going to be more important than the absolute level of subsonic frequencies?

Overall, yes. Impulse and Step response look good, and it sounds very good.

Phase correcting the bass implies large FIR filters and higher latency presumably..? For example, the Kii Three in normal operation has 90ms latency, but also has a low latency mode for real time monitoring.

My DSP has 6144 taps@48kHz. Using a manual FIR generator, rePhase, I was able to twist the bass phase down to zero degrees with that hardware, but AcourateDEC isn't so brutal in its approach, nor is it as tweekable as the full Acourate software. Latency is short enough not to be objectionable with the TV, maybe just noticeable if you pay close attention, or watch someone playing an instrument. Mostly I'm not that attuned to the video aspect. I'm not sure using it is any worse than the variations seen in lip-sync without it from various video sources.

 

[dallasjustice]

Two full range speakers are almost never capable of delivering good quality bass. The problem has almost nothing to do with speaker design. Lack of bass linearity is primarily a room physics problem/solution. If you add two subs and set them up well, you'll get much better bass than just 2 full rangers; every time. It is more helpful if you can post 1/12th per octave or higher smoothing.

 

[RayDunzl]

It is more helpful if you can post 1/12th per octave or higher smoothing.

No smoothing applied (above, Post #1, 5, 7).

 

[NorthSky]

Something like this Michael:

 

[dallasjustice]

This is the new trend is stupid expensive audio. The idea is that more bass towers equals better bass. That's not how it works. The bass problems in most rooms cannot be overcome just because one buys more subs. Where the subs are located and how they are used matters. The size/setup of these bass towers only shows the speaker manufacturer and their customers are totally ignorant about basic room acoustics.

From a marketing perspective, these new types of speakers fit nicely with audiophile folklore. The "more is better" people love it!

Something like this Michael:

 

[dallasjustice]

No smoothing applied (above, Post #1, 5, 7).

They look smoothed to me. I guess it all looks really good then except the big dip which is likely a boundary. At what sample rate are you recording your logsweeps?

 

[RayDunzl]

They look smoothed to me. I guess it all looks really good then except the big dip which is likely a boundary. At what sample rate are you recording your logsweeps?

Heres's a full sweep, with 1/48 to clear the hash at high frequencies, same scale as the posts above...

Fastest sweep (128K), because I haven't seen it make much difference in the SPL traces, and 48kHz sample rate.

The 48hz dip explained in post #7, phase anomaly at room node. I could probably fix that (it isn't objectionable) with sub placement (probably with the CheezeWoofers I already have). But it isn't really noticable with music

Here's the whole Phase measurement:

The phase of the left and right diverge - by nearly 180 degrees around 48 Hz, causing cancellation, at the single-measurement microphone.

I haven't figured out the difference on left and right around 600 Hz, but it goes away with both speakers (red).

 

[NorthSky]

But subs that have drivers near the floor, in the middle and @ top are superior than square boxes you put on the floor and restricted to 24 or 36 inches high.
And those subwoofers columns you can position them anywhere where they sound best; inside, outside, behind, in front of the main columns.

And not only they perform better, but they look better too. They have high class looks on top of their superior sound performance.
You don't agree with that, Michael?

Usually the rooms where such systems end up are acoustically treated. Not all companies (like Bryston for example) are into DSP messing.
Keeping the crossovers simple and without digitally altering the audio signals from your turntable and tape deck with DSP massaging/manipulation are the goal of audiophile purists. I highly respect those goals when it comes to serious music listening with respect to the best music recordings, in reproducing them accurately and with full integrity.

I am not against DSP room correction; I simply respect music simplicity and elegance. Pleasure in life takes many paths for many people...
And besides, you can almost measure all various systems; with graphs and with emotional impact from the listeners themselves, which is a very personal experience without absolute and with pleasurable definition.

Those sub columns are separate too, and it's not a trend because they've be around for many years, and for very good reasons...main one being superior performance. And even subwoofer's manufacturers are designing subwoofers more and more with multiple elevated drivers. Would you like me to give you some extraordinary performing examples?

Top-notch bass frequencies are not strictly the domain of the restricted floor area. Bass experts know that stacking subs on top of each other, and up to near the ceiling helps improving bass frequencies in better balanced distribution in a room. Would you agree with that?

* Prove to me the stupidity and ignorance of such systems (separate quad towers) Michael.

 

[dallasjustice]

Heres's a full sweep, with 1/48 to clear the hash at high frequencies, same scale as the posts above...

Fastest sweep (128K), because I haven't seen it make much difference in the SPL traces, and 48kHz sample rate.

View attachment 2812

I was referring to the sample rate not the logsweep duration. It all looks pretty good to me except the two dips. Those are caused by boundaries.

 

[RayDunzl]

Prove to me the stupidity and ignorance of such systems (separate quad towers) Michael.

What you are showing is like €150 000 ($167,925) stupid, not counting the rooms and ancilliary equipment.

Got some measurements for them?

 

[NorthSky]

...Coming right up.

 

[RayDunzl]

It all looks pretty good to me except the two dips. Those are caused by boundaries.

My room is 18'6" long, and the left 1/3 is open and the wall there is 27'10". Something like this:

 

[NorthSky]

I'm still searching...for real world measurements...be patient.

• http://www.gryphon-audio.dk/products/loudspeakers/pendragon.aspx


The Bass Foundation
"To keep pace with the extraordinary speed and openness of the dipolar drivers and eliminate the discontinuity that plagues more conventional “hybrid” speakers, the Pendragon bass tower offers elegantly simple and original Gryphon solutions to a number of complicated problems.

Deep bass is, perhaps counter-intuitively, the most difficult part of the audio spectrum to reproduce with both accuracy and seamless integration with the upper frequency range. A full-range speaker with bass drivers built into the main enclosure has its own set of demons to exorcise as does the currently popular approach of tacking on a so-called “subwoofer” for bottom end duties.

Each Pendragon bass tower houses eight custom designed 8” drive units and a built-in, specially designed Gryphon Class A/B power amplifier capable of 1,000 Watts continuous output. For extended headroom, available peak power is approximately 4,000 Watts or 4.5 horsepower.

The Pendragon amplifiers are everything you would expect from Gryphon with 18 high current bipolar output transistors, 200,000 microFarad capacitor bank, DC servo-coupling, zero global negative feedback, military spec. double-sided printed circuit boards and magnetically shielded Holmgren toroidal transformers mounted directly on the rear panel of the cabinet.

Active bass allows the user to select a separate amplifier for the high frequency panels without having to worry about the power demands of the massive Pendragon bass system.

By physically separating the bass and upper frequency sections, Gryphon Pendragon elegantly sidesteps the issues that inevitably arise in a full-range cabinet or in a satellite/subwoofer configuration.

Conventional passive loudspeakers must be designed for compatibility with a wide range of commercially available power amplifiers and active subwoofers are typically driven by an off-the-shelf “digital” power module that could fit in one hand.

By way of comparison, the purpose-built, onboard Pendragon power amplifier weighs in at 70 kg per tower!

Naturally, ideal integration with the Pendragon high frequency panel is assured.

Significant effort and resources have been focused on delivering extended deep bass with articulation, force and authority, completely independent of the acoustic environment.

To achieve this ambitious goal, the amplifier incorporates sophisticated Q Control circuitry to fine-tune bass response as well as additional adjustments to ensure ideal room interface. The bass remote control allows adjustment of bass level, Q, low cut and other parameters directly from the listening position.

The bass module offers Standby mode and provides effective driver protection via a comprehensive non-invasive system that monitors all functions more than 100 times per second.

The singular bass performance of the Gryphon Pendragon system heightens awareness of rhythmic subtleties and nuances as it immerses the listener in music’s rhythmic power."

 

[RayDunzl]

Why do you post this stuff? (Ok, that's sort of harsh, but it was my thought)

Everyday you're excited about something new...

I'm much more interested in what we have...

 

[NorthSky]

Why do you post this stuff?

Everyday you're excited about something new...

Because I do exist and have thoughts I like to share with others.
And yes, every single day I am excited about life and everything that is inside and outside of it.

I brought up separate Subwoofer towers as an alternative to full range loudspeakers, or/and regular "square box" subwoofers.
Your room Ray, with your speakers and their measurements are very impressive, and it seems that you don't really need external/separate subwoofers of any kind.
You have all the low extension that you'll ever need with your stereo music listening...most music recordings (the vast majority) have no real content below say 30Hz.

But for some audiophiles the addition of separate subwoofers with their own amplification can make a tremendous difference for the better when playing their favorite music genre recordings @ realistic volume levels. There is no substitute for enveloping and balanced bass all around filling the entire room @ real live disco levels.

I checked with Stereophile but nothing on those specific loudspeakers (Gryphon Pendragon) and their measurement from John Atkinson or others.

 

[Blumlein 88]

Looking at your listening area Ray, it is clear the dips are from the kitchen countertop. Don't know if it is marble or other hard substance. It probably should have been made of sound absorbing foam.

Just kidding. Your measured in room performance is exemplary here for the most part. Nothing to be ashamed of by any means. Does the frequency dip coincide with the distance between your speakers. I have seen that sort of effect with dipoles before. Something around 11 to 12 feet between speakers would fit.

 

[RayDunzl]

Your measured in room performance is exemplary here for the most part.

Thank you for the compliment.

Does the frequency dip coincide with the distance between your speakers. I have seen that sort of effect with dipoles before. Something around 11 to 12 feet between speakers would fit.

I measure about 8' 2" between centers, the panels/cabs are 18" wide. Ceiling height is 9'4".