Wharfedale Super 10/RS/DD cabinet advice

I'm having a clear out and found a working pair Wharfedale super 10rsdd which I though I could sell.
I tested them to make sure they sounded right and I was suprised how good the were without a cabinet.
I'm wondering whether i should keep them
I have seen the design in the publication below which shows a cabinet 28x16x10 inches
I can live with the size but I don't like the shape, can I alter the dimensions whilst retaining the cubic volume
without affecting the performance?
I was thinking 24" high 13" wide and 14.3" deep with a 13" x 3/4" slot at the bottom and moving
the speaker unit to the top of the cabinet.
The other thought was would a tuned port tube sound better than a thin slot?

http://ukhhsoc.torrens.org/makers/Wharfedale/Wharfedale_cabinet_construction_sheet_October_1965.pdf
 
which shows a cabinet 28x16x10 inches

That'll be cabinet R2 - 2 cu ft!

I built the larger R3 - 3 cu ft - for a friend back in the 1970s - the bigger the better for the powerful magnet Super 10!

You can certainly alter the dimensions. Briggs (founder of Wharfedale) also recommended a 2 cu ft enclosure 26" x 14" x 12" (external dimensions, 3/4" plywood)) with a slot 10" by 1"

He wrote: "A 10% alteration to dimensions is usually harmless, but it would be quite wrong to reduce all dimensions by 10% as this would knock 27% off the total volume."

I don't foresee any problems with your alterations as long as the internal volume remains at 2 cu ft - the main thing is to avoid a "double cube" shape.

The thin slot tunes the enclosure broadly and accommodates slight variance in driver resonant frequency.

Briggs gave a formula for a traditionally tuned port which is used to tune the enclosure to the exact resonant frequency of the particular Super 10.

Without the Thiele/Small parameters of your particular Super 10s, it would not be possible to design the most effective port dimensions as is done nowadays.
 
Now that I think back, I used the 26" x 14" x 12" enclosure with narrow slot to house my friend's Super 10s.

(I'm sure of the 12" depth as I used 12" wide, wood veneered Contiboard from Timberland in the construction!)

I built the larger R3 distributed port (holes in the back) enclosures to house my Wharfedale RS/12/DD 12" full range drivers.

Both driver/enclosure combinations delivered lean, clean bass without any trace of boominess. My friend, with his love of classical music, particularly liked the quality of reproduction from the Super 10 enclosures.

Thanks for listening to the history lesson - them were the days! ;)
 
Interesting, thank you for that.
I bought the pair at a boot sale for £5 years ago not knowing they needed a huge cabinet, one of them has a badly dented dust cap though.
When you say "lean" do you mean the bass output is low or some what lacking?
 
By "lean", I mean "not fulsome", i.e., not "in your face". Expect an extended, but not emphasised, bass response.

What you get with these powerful magnets is control over the cone movement which results in good transient response - sometimes referred to as "speed".

With the Super 10/R2 enclosure combination you won't get the artificial rise in response at upper bass frequencies which many modern speakers employ to give an impression of bass extension when there isn't actually any low bass present.

It depends on the type of music you play. If you are a "bass freak" then the combination may not be for you.

A tube port that tunes the enclosure to just above the resonance frequency of the Super 10 would give more bass reinforcement.

In his book Loudspeakers, Gilbert Briggs gives a formula for calculating the length of pipe required for a given enclosure resonance frequency:

f^2 = (2700A) divided by V(L + 0.96√A)

where:

f = enclosure resonance frequency in Hz (f^2 = f squared)
A = area of pipe in square inches
V = volume of enclosure in cubic feet
L = length of pipe in inches

From past experience, I believe you would get good results with your Super 10s by choosing an enclosure resonance frequency of 40 Hz.

Even better if you were to build a 3 cubic foot enclosure!
 

GM

Member
Joined 2003
By "lean", I mean "not fulsome", i.e., not "in your face". Expect an extended, but not emphasised, bass response.
Indeed, due to the driver's low Qt, but what is usually not factored in when dealing with vintage drivers in general and especially WRT its various cab alignments is the electronics of the times' damping factor/output impedance (series resistance) that increases the driver's effective Qts (Qts'), so this 'lean' bass can be mimic'd somewhat to its 'fullsome' by adding a series power resistor and/or an adjustable pot to dial it in or leave in place as I did.

1965 electronics directory listing pertinent specs
 
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Indeed, back in the time period of these Wharfedale drivers they would have been driven by a valve amplifier with a highish output impedance.

This additional resistance acts to counteract the high level of magnetic damping and can peak the bass up a few decibels.

My Wharfedale drivers only sound their best when driven by the Rogers valve amp that was their contemporary.

I've tried the series power resistor 'trick' with other speaker/amplifier combinations with mixed results.

P.S. That 1965 directory is a big pdf - 182 pages!