Hartley woofer

[Steve Mac]

I have one of these. scroll down for pics…
https://steevee.com/stereo-info
I would love to resurrect this fella but cannot withstand…in this particular case…a overly large cabinet.
This was the speaker I had built a huge folded horn sub for my Dad’s system and it sounded great.
Well, I have a pair of Magnepan 3.5s and will need a sub when I can get to it.

As usual, during my search for info…that @GM was involved in a thread over at diyaudio.
https://www.diyaudio.com/community/t...ley-24.106532/

[GM]

Well, depending on how low you want it to go at 'x' peak SPL, just mounting it on a sturdy 2x4 ~24" square frame and placed on, and perpendicular to, the floor (reinforced somehow if a 'floating' one like mine) will load down to ~120-130 Hz and it high Qt will fill in somewhat below it, so depending on where in the room it is relative to its room modes, may 'pound sand' all the way to Fs and beyond.

Use fore, aft legs with some triangulation bracing for laying trash bags of sand/whatever draped over the legs to damp/'plant' it to the floor.

A cheap, easy way to experiment if nothing else.

[Steve Mac]

Well, depending on how low you want it to go at 'x' peak SPL, just mounting it on a sturdy 2x4 ~24" square frame and placed on, and perpendicular to, the floor (reinforced somehow if a 'floating' one like mine) will load down to ~120-130 Hz and it high Qt will fill in somewhat below it, so depending on where in the room it is relative to its room modes, may 'pound sand' all the way to Fs and beyond.

Use fore, aft legs with some triangulation bracing for laying trash bags of sand/whatever draped over the legs to damp/'plant' it to the floor.

A cheap, easy way to experiment if nothing else.

Thanks @GM !

How about a bass reflex enclosure. Any ideas ?
Maybe the sub could go in the middle and be used to put a TV on top.
Not expecting this system to be uber loud but accurate would be nice.

[GM]

You're welcome!


Again, based on these specs from the other thread and known to historically only being used in OBs, closet size sealed boxes it takes a humongous box, though nowadays we can use DSP/room EQ to frequency shape it to whatever in room response we want within its box tuning/minimal Xmax limits.

Fs = 20.9Hz
Qts = 0.65
Qes = 0.74
Re = 3.7 ohms
VAS = 1250 litres
Sd calc to 0.22 sq metres


For instance a T/S max flat alignment driven with a modern day amp's extremely high DF (insignificant output impedance):

net volume (Vb) (L) = 20*1250*.65^3.3 = ~6033.29 L/213.37 ft^3


box tuning (Fb) (Hz) = 0.42*20.9*.65^-0.96 = ~13.3 Hz


If we use the pioneer's 'classic' BR alignment, which really only applies to drivers with < ~0.4 Qts, then still 1250/1.44 = ~868 L/30.65 ft^3 tuned to Fs, so is this an OK i.d. size/tuning or what max O.D. dims can you tolerate and 'it is what it is'?

[gortnipper]

I have just ordered parts to build a pair of these to run thru a Crown amp. Cheap as chips. People seem to love them and @alancohen runs them with hs A5s.

https://www.transcendentsound.com/bucket-sub.html

https://www.hostboard.com/forums/sho...ghlight=Bucket

https://audiokarma.org/forums/index....isited.658794/

[Old Guy]

these are good for bucket subs

https://www.milehighonthecheap.com/f...ickle-buckets/

[Steve Mac]

You're welcome!


Again, based on these specs from the other thread and known to historically only being used in OBs, closet size sealed boxes it takes a humongous box, though nowadays we can use DSP/room EQ to frequency shape it to whatever in room response we want within its box tuning/minimal Xmax limits.

Fs = 20.9Hz
Qts = 0.65
Qes = 0.74
Re = 3.7 ohms
VAS = 1250 litres
Sd calc to 0.22 sq metres


For instance a T/S max flat alignment driven with a modern day amp's extremely high DF (insignificant output impedance):

net volume (Vb) (L) = 20*1250*.65^3.3 = ~6033.29 L/213.37 ft^3


box tuning (Fb) (Hz) = 0.42*20.9*.65^-0.96 = ~13.3 Hz


If we use the pioneer's 'classic' BR alignment, which really only applies to drivers with < ~0.4 Qts, then still 1250/1.44 = ~868 L/30.65 ft^3 tuned to Fs, so is this an OK i.d. size/tuning or what max O.D. dims can you tolerate and 'it is what it is'?

Fascinating, as Spock would say. So thanks!

Now if I were to say what the desired dimensions would be they would look something like:
Depth: 1.75 ft
Height: 2.5 ft
Length: some latitude but desired ~3.5 ft
~15 ft3

The listening area is a little over 9 ft wide(30ft long) and the planars I need to give a couple of feet minimum.

- - - Updated - - -

these are good for bucket subs

https://www.milehighonthecheap.com/f...ickle-buckets/

I do remember a secretary who would always refer to engineers as bucket heads. So you may be onto something.