Øyvind Kvålsvoll@kvalsvoll
528 Posts
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Quote from Øyvind Kvålsvoll on 13/08/2021, 04:22
In the system+room described here https://www.kvalsvoll.com/blog/kvalsvoll-design-audio-forum/topic/case-fixing-room-acoustics-for-a-f205-system/ I mentioned 2 small subwoofers were added just behind the listening position. These small T6 units fixes a problem that both the owner and I observed when listening.
What did we do, why, and how does this work out.
When optimizing a bass-system, we look into 3 properties of sound in the bass range:
- Reasonable frequency response
- Good time-domain response
- Good tactile response
This is achieved by installing a bass-system with sufficient capacity and frequency range extension, and tuning using eq and delay to achieve the desired result. Sometimes it is sufficient to install 2 subwoofer units up front, while in some rooms and systems additional subwoofer units placed at the back may be required.
This is the room, with the bass-system consisting of 2x T6018 main front units and 2x T6 rear units:
I will show how this system was fixed by tuning with eq and delay, and why the owner decided to add the two rear T6 subwoofer units. Stay tuned.
In the system+room described here https://www.kvalsvoll.com/blog/kvalsvoll-design-audio-forum/topic/case-fixing-room-acoustics-for-a-f205-system/ I mentioned 2 small subwoofers were added just behind the listening position. These small T6 units fixes a problem that both the owner and I observed when listening.
What did we do, why, and how does this work out.
When optimizing a bass-system, we look into 3 properties of sound in the bass range:
- Reasonable frequency response
- Good time-domain response
- Good tactile response
This is achieved by installing a bass-system with sufficient capacity and frequency range extension, and tuning using eq and delay to achieve the desired result. Sometimes it is sufficient to install 2 subwoofer units up front, while in some rooms and systems additional subwoofer units placed at the back may be required.
This is the room, with the bass-system consisting of 2x T6018 main front units and 2x T6 rear units:
I will show how this system was fixed by tuning with eq and delay, and why the owner decided to add the two rear T6 subwoofer units. Stay tuned.
Øyvind Kvålsvoll@kvalsvoll
528 PostsTopic Author
AdminCompany InsiderModerator
Quote from Øyvind Kvålsvoll on 04/09/2021, 22:04
To understand why a typical frequency response measurement does not tell the full story, we need to know how sound actually works, I have started a thread on this, for those who want a more technical view:
https://www.kvalsvoll.com/blog/forum/topic/sound-field-properties-relevant-for-low-frequency-reproduction/
To understand why a typical frequency response measurement does not tell the full story, we need to know how sound actually works, I have started a thread on this, for those who want a more technical view:
https://www.kvalsvoll.com/blog/forum/topic/sound-field-properties-relevant-for-low-frequency-reproduction/
Øyvind Kvålsvoll@kvalsvoll
528 PostsTopic Author
AdminCompany InsiderModerator
Quote from Øyvind Kvålsvoll on 06/10/2021, 11:39
With 2x T6018 subwoofers placed in front corners, measurements show that it is likely that a reasonable response is achievable. The room has acoustic treatment tht also works at least partially down into the bass range, and we see there is only one larger resonance around 40Hz, the rest looks quite clean for a starting point.
Frequency response raw:
Decay 2x T6018 subwoofers before calibration:
The response was shaped with a slight lift towards lower frequencies, and all resonances were removed. The result looks promising.
Decay 2xT6018 subwoofers after initial eq:
With 2x T6018 subwoofers placed in front corners, measurements show that it is likely that a reasonable response is achievable. The room has acoustic treatment tht also works at least partially down into the bass range, and we see there is only one larger resonance around 40Hz, the rest looks quite clean for a starting point.
Frequency response raw:
Decay 2x T6018 subwoofers before calibration:
The response was shaped with a slight lift towards lower frequencies, and all resonances were removed. The result looks promising.
Decay 2xT6018 subwoofers after initial eq:
Øyvind Kvålsvoll@kvalsvoll
528 PostsTopic Author
AdminCompany InsiderModerator
Quote from Øyvind Kvålsvoll on 07/10/2021, 07:27
Integration
Delay on F205 main speakers determines timing for integration between bass-system and main speakers. When this is set correct, frequency response sums up perfect, and phase is flat or very close to flat, across the crossover region.
Correct roll-off on both bass-system and main speakers are required to be able to integrate the system properly. With DSP on both bass and main speakers, this is possible to do, and make the roll-off slopes have the desired slope and remove resonances and peaks that can occur out-of-band. The F205 is borne with roll-off below 120Hz, which makes it much easier to integrate, a full-range speaker will typically have peaks below desired roll-off that can be difficult to manage, especially if there is no DSP on the mains.
Integration
Delay on F205 main speakers determines timing for integration between bass-system and main speakers. When this is set correct, frequency response sums up perfect, and phase is flat or very close to flat, across the crossover region.
Correct roll-off on both bass-system and main speakers are required to be able to integrate the system properly. With DSP on both bass and main speakers, this is possible to do, and make the roll-off slopes have the desired slope and remove resonances and peaks that can occur out-of-band. The F205 is borne with roll-off below 120Hz, which makes it much easier to integrate, a full-range speaker will typically have peaks below desired roll-off that can be difficult to manage, especially if there is no DSP on the mains.
