Pmc 24

[Puma Cat]

Nothing against PMC in particular, but I find the.model nomenclature of many British speaker brands exceptionally confusing what with PMC OB1i, Harbeth P3ESR, Audio Note AN-E SPe, etc., it's like trying to keep track of the various models of Harley-Davidsons.

[BuffaloBill]

Originally Posted by Puma Cat

Length of the transmission line.

I was looking for a little deeper answer.

[Removed]

Originally Posted by BuffaloBill

I was looking for a little deeper answer.

I can't give you the technical answer as I'm not a speaker builder but here is a brief answer as why they play low.....PMC Ltd scroll down to techically speaking....maybe Ian can add to this.

[Puma Cat]

Originally Posted by BuffaloBill

I was looking for a little deeper answer.

Sorry, hope my answer didn't come across as supercilious.

I don't know very much about transmission line speakers, but my understanding is that the transmission line functions as a "folded horn" inside the cabinet, allowing a smaller driver to produce a lower fundamental bass response than other non t-line designs, e.g. acoustic suspension.

In particular, "transmission line" is the name of a specific audio speaker enclosure topology, in which sound from the back of the bass speaker chassis passes along a long (generally convoluted) path within the speaker enclosure. The energy is absorbed on this path, or emerges from the open end in phase with the sound radiated from the front of the driver, enhancing the output level at low frequencies. Note the key word in this description is a "long" path.

http://upload.wikimedia.org/wikipedi...ssion-line.png

Note that in this diagram, the bass driver is mounted up high in the cabinet to help provide additional length to the t-line, just as it is in the 24.

The reason this toplogy has not been utilized to the extent that acoustic suspension or bass reflex designs have is that it requires a more complex internal cabinet structure and therefore is more expensive to manufacture. For mass-produced low or mid-fi speakers, it simply cheaper to put a larger driver in a simple enclosed or ported box.

So, while my answer may have at first seemed supercilious, it is in fact the length of the t-line that allows a small 6.5 bass driver to produce bass response down to 28 Hz. . The design, shape, folding and port relationships are also critical adjustment parameters for the critical functional response, namely the bass response.

Hey, Jerome, it just occurred to me that one could apply Design of Experiments (DOE) here, too! (see my thread on DOE for sub integration in the general audio discussion forum).

[Removed]

Stephen.....click the link I provided above, simple but should shed a bit more as to why they get the low numbers....

[Removed]

Originally Posted by Puma Cat

Nothing against PMC in particular, but I find the.model nomenclature of many British speaker brands exceptionally confusing what with PMC OB1i, Harbeth P3ESR, Audio Note AN-E SPe, etc., it's like trying to keep track of the various models of Harley-Davidsons.

You forgot to list Dynaudio

[Puma Cat]

Well, admittedly Dynaudio's lineup nomenclature isn't the clearest on the planet either, but there is some semblance of logic behind it, you have four basic product lines that are well differentiated from one another from a marketing, performance and price perspective: Excite, Focus, Contour, and Confidence (I'm specifically excluding the über-high end Evidence line which has only two speakers).

Then within a line you have a simple numbering system that goes from small to large as the speaker gets larger. For example, Focus 110, 220, 360 or Confidence C1, C2, C4, etc. Perhaps not the simplest nomenclature, but way less cryptic than many of the British manufacturers, IMO.

[Puma Cat]

Originally Posted by A/V Solutions

Stephen.....click the link I provided above, simple but should shed a bit more as to why they get the low numbers....

Thanks, Jeff, I will definitely do that...I admit I am fascinated by this speaker design approach as it lends itself to DOE.

[Jerome W]

Originally Posted by Puma Cat

Sorry, hope my answer didn't come across as supercilious.

I don't know very much about transmission line speakers, but my understanding is that the transmission line functions as a "folded horn" inside the cabinet, allowing a smaller driver to produce a lower fundamental bass response than other non t-line designs, e.g. acoustic suspension.

In particular, "transmission line" is the name of a specific audio speaker enclosure topology, in which sound from the back of the bass speaker chassis passes along a long (generally convoluted) path within the speaker enclosure. The energy is absorbed on this path, or emerges from the open end in phase with the sound radiated from the front of the driver, enhancing the output level at low frequencies. Note the key word in this description is a "long" path.

http://upload.wikimedia.org/wikipedi...ssion-line.png

Note that in this diagram, the bass driver is mounted up high in the cabinet to help provide additional length to the t-line, just as it is in the 24.

The reason this toplogy has not been utilized to the extent that acoustic suspension or bass reflex designs have is that it requires a more complex internal cabinet structure and therefore is more expensive to manufacture. For mass-produced low or mid-fi speakers, it simply cheaper to put a larger driver in a simple enclosed or ported box.

So, while my answer may have at first seemed supercilious, it is in fact the length of the t-line that allows a small 6.5 bass driver to produce bass response down to 28 Hz. . The design, shape, folding and port relationships are also critical adjustment parameters for the critical functional response, namely the bass response.

Hey, Jerome, it just occurred to me that one could apply Design of Experiments (DOE) here, too! (see my thread on DOE for sub integration in the general audio discussion forum).

Very well explained Stephen !

[Puma Cat]

Originally Posted by C220MC275

Very well explained Stephen !

We scientists can be useful around the house!