PRaT trumps all

[Haselsh1]

My room is 18ft long yet I get bass to below 20Hz. I can even measure it as such with m XTZ mic and analyser software. I know it's been said we need the full wavelength but I don't believe it. If so I'd only get bass to 60Hz.

Totally agree, you do not need the entire wavelength but if you do not have the entire wavelength then you do not have the correct frequency only a harmonic of it.

[SPS]

Yeah the difference is very big indeed but then consider the weight of a 15" cone compared to a 5" paper cone. Then think about the inertia of that 15" cone.

Found this review of some speakers with twin 5" cones... sounds very much like my experiences hearing these type of speakers, again my preference is high efficiency and much larger speakers, for me the texture and resolution is paramount ...

Playing Massive Attack's Mezzanine, for example, especially the standout track Inertia Creeps, which uses several instruments through the bass region, it was quite difficult to distinguish the separate parts. Furthermore, the rather limp and vague bass delivery lacks the grip and momentum needed to bring the music properly to life and provide it with sort of tension and sense of drive that's essential in conveying the menace inherent in this track.

[Clive]

Totally agree, you do not need the entire wavelength but if you do not have the entire wavelength then you do not have the correct frequency only a harmonic of it.

How then does my mic register the fundamental frequency? It measures 20Hz in my room where the wave isn't fully formed - the theory says it should only register from around 60Hz given my room dimensions.

[Yomanze]

Found this review of some speakers with twin 5" cones... sounds very much like my experiences hearing these type of speakers, again my preference is high efficiency and much larger speakers, for me the texture and resolution is paramount ...

Playing Massive Attack's Mezzanine, for example, especially the standout track Inertia Creeps, which uses several instruments through the bass region, it was quite difficult to distinguish the separate parts. Furthermore, the rather limp and vague bass delivery lacks the grip and momentum needed to bring the music properly to life and provide it with sort of tension and sense of drive that's essential in conveying the menace inherent in this track.

Massive Attack, Mezzanine is one of my favourite albums, indeed a reference album, and I get none of what this is saying. Sounds to me either like a phase issue with the speakers, poor bass reflex loading, or lack of power on the amp side. You can’t just say that bigger speakers = more scale, in every room. It’s just that smaller ones need more power and excursion for the same SPLs.

[Yomanze]

Yeah the difference is very big indeed but then consider the weight of a 15" cone compared to a 5" paper cone. Then think about the inertia of that 15" cone.

And then consider how big the magnet is on the 15” driver, and how its excursion to reproduce bass frequencies is much lower than the 5”. It is harder to get the small driver to start and stop on a pinpoint. This is probably why some people seem not to like the sound of muscle amps on Tannoys i.e. an overdamped sound.

[SPS]

Massive Attack, Mezzanine is one of my favourite albums, indeed a reference album, and I get none of what this is saying. Sounds to me either like a phase issue with the speakers, poor bass reflex loading, or lack of power on the amp side. You can’t just say that bigger speakers = more scale, in every room. It’s just that smaller ones need more power and excursion for the same SPLs.

Of course you can't say bigger speakers are better, there are good and bad in everything as you know and there are compromises with all loudspeakers. I can only talk about my experiences ... always happy to put my speakers up for comparison though..

[RothwellAudio]

Inertia is an object's reluctance to be moved. To get over that inertia the amplifier has to use a good portion of its ability to drive to get that cone moving. As well as that, the amplifier has also to brake that cone to stop it rattling around. I do not wonder that an 8 Watt amplifier is so limited in its application.

Correct, which is why you can't get the 15" cone up to a high velocity from a standing start like you would a 5" driver. However, that's the same thing as frequency response. Think about it.

[SPS]

Correct, which is why you can't get the 15" cone up to a high velocity from a standing start like you would a 5" driver. However, that's the same thing as frequency response. Think about it.

Thats acceleration factor which can be quite low in inefficient smaller bass drivers and is a calculation based on speaker BL and voice coil length, many pa and old school type speakers may come out much better.. and it's not the same as frequency response

[RothwellAudio]

Thats acceleration factor which can be quite low in inefficient smaller bass drivers and is a calculation based on speaker BL and voice coil length, many pa and old school type speakers may come out much better.. and it's not the same as frequency response

Isn't it? If the coil has too much inertia to move backwards and forwards very fast, it won't reproduce high frequencies - hence tweeters have to be small and light. Obviously you need more acceleration/deceleration to move at 20kHz than to move at 100Hz, so how is cone mass and acceleration not linked to frequency response?

[Puffin]

Interesting chart of waveform lengths.

http://www.jdbsound.com/art/frequenc...art%202013.pdf