Dayton PS180-8

 

Can't believe these were purchased in 2014,  seven years ago.  At that time, I placed a project on Parts-Express Project gallery and somehow forgot to write this page.  Well, for all it's worth, here it is.

The speaker described here is the Dayton PS-180-8, the dash 8 meaning it's 8W.  The unit is still available from Parts Express, the part number is 295-344.

The Daytons, once seen on P.E. made me ecstatic (Dec. 2012). What a find. The last time I saw such a speaker was well over 50 years ago. It was the venerable GOODMANS AXIOM 80. I've seen some on auction websites bring as much as $4500.00 for a working pair.

The Daytons are housed in octagonal satellite cabinets with a minimal diameter to help reduce diffraction, however noticeable that may be, if at all; ergo, the front edges were not rounded. The wood is solid 0.75" purple heart, almost as hard as ebony. The internal volume is 0.22 ft^3 as per Bass Box Pro, ver.6 and are sealed with an optimal Q of 0.707. The fill is 352g of pure New Zealand wool, washed but otherwise NOT treated. These units were 'broken in' at 3mm excursion for about an hour at 10hz while periodically monitoring the voice coil temp with an infrared thermometer. The free air resonant frequency was reduced from about 60hz to about 48hz. The T/S parameters of these two units were then derived using L.M.S. (Loudspeaker Management System by Linear-X) and differ slightly from those of the manufacturer, due to the breakin.

The woofers are 10" MCM (now NEWARK) 55-2981.  They are housed in the 3 cu.ft. cabinets under and behind the end tables.  The data sheet can be found by clicking HERE

The amplifiers in the living room are all ADCOM. The Daytons are powered by a 60w/ch unit whilst the woofers are powered by 100w/ch. The preamp is fed through a Behringer model CX3400 electronic crossover.

These fellas have incredible transient response, almost like that of a horn.  They are efficient; their sensitivity is 95dB, 1W1M. Most of this is in the upper mid-range centered around 3khz so they had to be padded down with a notch filter.  It can be seen as a little brown box atop the base of the left satellite speaker in PHOTO 3.  The depth of the notch is adjustable to about -7dB

 

 

 

 

 

PHOTO 1

Purple heart was used for three reasons.  One, the price was reduced by 50% and two, the boards were the right width and their lengths were just right for two sides and three, it's purple.

PHOTO 2

     

 

 

 

PHOTO 3

The woofer cabinets for the satellites are under and behind the end tables.  I say 'under and behind' because they are L-shaped and are two cabinets latched together.  This made it easier.  Had the L-shaped sides been one piece, it would have been necessary to cut them by hand.   

 

 

 

 

PHOTO 4

Here's the opposite side of the room.  The response measurement was just performed.  The CLIO is left of the laptop.

Then turntable on the left is a Thorens TD-124 with a Shure SME3009 tonearm.  There are three heads, weighted for 1g force.  Two have Shure V15 Type III cartridges with new stylii, one for LP and one for 78 rpm.  Yes, I have several pristine 78s, bought for nostalgic reasons.  When flooded with distilled water during play, they can be damn close to LP quiet; the stylus will hydroplane in the groove.  Unfortunately, centrifugal force will send water horizontally if too much is used.  Just enough to flood the grooves without overflowing to adjacent grooves.  That stylus tracks at 3g.  There's a third head that has a Empire 999VE with a new original stylus.

Some SEM (Scanning Electron Microscope) photos of one of my stylii can be seen on this page 

 

 

 

 

PHOTO 5

The archway leading into the dining room, such as that is.  The partial wall on the right is about 7 ft. wide and the archway is about 11 ft. wide.

The two speakers in the background are the EMPIRE look-a-likes.  They were moved there as the living room was way too cluttered, even for MAF, my acceptance factor.  They actually sounded better there than in the living room.  Here, they have more clearance on the sides, especially the one on the right as it's close to the kitchen entrance.

The hallway opening is between these two rooms and is on the left.

The room acoustics regarding the bass is PDF, pretty darn flat below 200hz but this isn't so with the speakers in the corners.

I built the arch in 1975 when I bought the house.  Crap, when I retired in 2003, I bought a new Infiniti which cost as much as the house did.  I still have that car and today, it has very little resale value but the house, well, I guess that's why it's called real estate.

 

 

 

 

FIGURE 1

This is a normalized frequency response of the Dayton and was the decision maker to high pass filter it at 200hz.

FIGURE 2

These two curves show the amplitude response if the MCM woofer (RED) and the Dayton (orange)  As can be seen, the Dayton is about 4dB more sensitive than the MCM, above 200hz.  The MCM is about -9dB at 35hz.  This fall is due to diaphragm area, not excursion as at 1 watt, the diaphragm is nowhere near it maximum excursion, Xmax.  As the diaphragm is forced to move farther, the rate of attenuation (compression) gradually increases due to the non-linearity of the suspension.  This is usually small, though, in a well designed speaker.  When Xmax is reached, compression rises fast and if pushed further, destruction of the speaker results.  If the suspension is strong enough to hold together, the voice coil will heat up and if luck prevails, will fuse open.  If not, it can set the speaker on fire.  I've seen a few musicians' speakers and cabinets after such an event.  I can only imagine the excitement of witnessing such an event.  This is highly frowned upon for obvious reasons.

Bass Box Pro doesn't show the effect of compression due to the non linearity of the suspension.   For more on that, see this page.

Loudspeaker Suspension Linearity

 

 

Speaking of speakers catching fire reminded me of the following although it has nothing to do with speakers but a lot to do with sensationalism, deliberate or not.

Back in the late fifties, one famous rock star Jerry Lee Lewis, while singing Whole Lotta Shakin' Goin' On  on stage while playing an open grand piano, squirted lighter fluid into the piano followed by a lighted match.   The movie "Great Balls of Fire" shows him doing that during the song Great Balls of Fire which seems to be a more appropriate song for the stunt.  It's on the TOOB.

https://www.youtube.com/watch?v=8ydiFsRuesM

They're not called the fabulous fifties for nothing.

What an era; at least from the point of view of an old buzzard like me who was a teenager then.

 

 

 

 

FIGURE 3

Just the impedances of the two Daytons.

 

 

 

 

FIGURE 4

A response curve, not gated, run in my living room.  Remarkably flat +3dB to -4dB between 100 and 20khz.

Notice that the response goes to 30khz so the last division at the right can be ignored.

This response also includes the room effects as the curve was not run gated; it's a continuous logarithmic sweep.

 

 

 

 

FIGURE 5

Here we have 3 traces.  The GREEN is the left channel only; the RED is the right channel only and the BLUE is both.

The peak between 70hz and 90hz can be objectionable with certain music but is easily removed with an equalizer or even a counterclockwise partial rotation of the bass control.

These traces were not run under a 1W1M condition,  It's pink noise fed into an FFT (Fast Fourier Transform) analyzer, part of the CLIO.  The actual SPL in the room was about 80dB and the mic was placed several feet from the speakers, equidistant from both.

See PHOTO 4

 

 

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