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Kvalsvoll

Bulding the Room2 listening room

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@maxmercy, I use a modified 10" driver, it is an old discontinued seas. 10" is a good size - good area for sensitivity, not too large so it does not change the sound field it is supposed to measure.

The 3x has less velocity in the important 30-40hz range, and a little less above up to around 120hz. Changing eq or delay on the BL back unit changes velocity response.

The 3x sounds better because it fills in a dip in the response around 60hz, phase is same, spectrogram is a little better.

The loss in velocity 30-40hz is noticeable. The increased v at ulf is more noticeable, because low freq noise stands out and becomes annoying - too much is not good. Further experiments can be to move the high-pass on the BL up in frequency, this will change the phase and perhaps make the velocity smoother - less ulf, fill in the dip 30-40hz.

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Testing midbass horns in Room2.

Calibration is complicated, and benefits in this system and room are questionable. This is just to ensure they work, and to learn how to set up and calibrate the system, so that the customer can receive some useful guidelines.

Usable range around 45hz up to 200-300hz, but for cf above 150hz you should absolutely use stereo processing, so for a typical av-processor system with bass-management it can be used up to 150hz.

Capacity around 120dB+, depends on how much power you have.

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26 minutes ago, Ricci said:

What type of alignment are those? TH?

Compact Horn, basically a rear loaded horn with resonance chamber for extended usable range.

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Maximum speaker delay in processors/receivers - a critical property, which is usually not sufficiently described in the manual or product presentation.

Anyone know the limits for different types, brands? I seem to remember this issue has been up before, but oooohhh.. using the rest of the day searching will not happen, and new information and new models may be available.

 

The problem:

Getting the timing correct is crucial for high performance sound quality. For systems with front main speakers and separate bass system that means to delay the main speakers so that they sum correctly with the bass system in the frequency response AND IN TIME/PHASE.

On most processors this is done by setting a distance on the different speakers. Typically, you set the front to the measured physical distance, and end up adding several meters for the bass system (subwoofer)  - THIS WILL DELAY THE FRONT SPEAKERS.

If you know what you are doing, you set the delay using measurements, so that timing and phase gets as good as possible to achieve. If you read on-line guides and audiophile magazines and pay no attention to how things really work, you set the distance for the bass-system equal to the physical measured distance, and conclude that subwoofers always sound kind of sluggish and is best switched off for music.

Since you are smart, you want to do it the way that actually works to get better sound, and end up seeing that the distance entered can be quite huge. And in some cases it may be possible to reach limitations of the processor in use. Obviously this is a no-go limitation for a processor, so if you have an installation that you know will require large delays, you want to choose a processor that satisfies this requirement. You want to see a specification for this number.

But this number is not in the brocheur or manual, it is not in any "test" performed by on-line or paper magazines - because the don't even understand why this number is important - so the only way to know is if someone have found the data.

 

My contribution:

Denon/Marantz processors, AVR:  Max distance difference 6m / equal max delay 18ms.

Devialet amplifiers: 20ms. 

Hypex DLCP and my SA-700 amplifiers: 15ms. (Though not relevant on the sub amp, becuase it is the mains that need delay.)

Onkyo processors, AVR: ???

Some readers now realize I need those numbers for the Onkyo.

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My Denon 3313CI AVR offers up to "60 feet" distance (a bit over 50 ms, in terms of delay) and a maximum difference of "20 feet" (~17.5 ms).

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1 hour ago, SME said:

My Denon 3313CI AVR offers up to "60 feet" distance (a bit over 50 ms, in terms of delay) and a maximum difference of "20 feet" (~17.5 ms).

Same as the Marantz and Denon I tested, it is very likely they share the same processing.

Note that it is the DIFFERENCE (17.5ms/20ft) that is interesting, as this is the number that defines how much delay is possible on the closer speaker to make it match the farther.

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