The response will increase over the entire sub range, not just LF.
With wings slightly more than doubling the frontal area of my TH and FLH subs, they gained 3 dB, enough to keep the 3015LF out of the "flap zone"
.http://www.diyaudio.com/forums/subwoofers/184986-horn-extender-wave-guide-th.html
The same wings flat also worked well on little BR monitor cabinets.
http://www.diyaudio.com/forums/subwoofers/204472-multiple-cabinet-combined-response.html
Art
Hi Art,
I don't see any difference between your statement and mine. Improvement of its directivity is over the entire bandwide (within the wavelength of the reflecting surface).
The gain down low is the result of the difference in 'End Correction':
0.6 of the radius (without wing)
8:3pi of the radius (with wing).
See Model
I don't see any difference between your statement and mine. Improvement of its directivity is over the entire bandwide (within the wavelength of the reflecting surface).
The gain down low is the result of the difference in 'End Correction':
0.6 of the radius (without wing)
8:3pi of the radius (with wing).
See Model
Hi Art,The response will increase over the entire sub range, not just LF.
With wings slightly more than doubling the frontal area of my TH and FLH subs, they gained 3 dB, enough to keep the 3015LF out of the "flap zone"
http://www.diyaudio.com/forums/subwoofers/184986-horn-extender-wave-guide-th.html
The same wings flat also worked well on little BR monitor cabinets.
http://www.diyaudio.com/forums/subwoofers/204472-multiple-cabinet-combined-response.html
Art
I've been thinking about using wings of delayed end-firing arrays to double down on the directivity control. More like dreaming really
Attachments
Perhaps a semantic difference, to me “a little” is a dB difference, not worth much effort.
A 3 dB boost (or more) over the entire sub range is the equivalent of using half the power, which when using drivers that sound bad at full power in a TH, is significant, not just a little.
I find this thread hilarious, over a year and not a single measured response, and the title abandoned, and a cabinet that rolls off at
Does the “end correction” model agree with my measurements?
Gee Art,
The OP already has a LF stack that he's been using.
As you know it's not so easy to get more LF from a 3015lf.
Dan,Hi Art,
I've been thinking about using wings of delayed end-firing arrays to double down on the directivity control. More like dreaming really
Not sure what your array would do at any given frequency, but it is not what we normally call an end fire.
From:
Phase Wavelengths: The End Fire Cardioid Array made visible Bob McCarthy's Blog
“The End Fire defined:
a line array of emitters (in our case: speakers) that are spaced and time-sequenced to provide in-phase addition on the forward side and out-of-phase rejection on the rear. The timing is set to compensate for the displacement between the sources in the forward direction. The most forward element is delayed the most, and sequentially less as we approach the last element.”
End fired arrays (as defined by Bob and generally accepted in the pro audio world) do not increase frontal area and forward gain (above the 6 dB per doubling of cabinets), they have less output than the same speakers in a large stack. They are often used for live shows because sight lines are obstructed with a large array of subs.
If one has the option of a large frontal area (whether a pile of subs or subs with wings), electronic means of achieving cardioid patterns are not needed.
Art
Thanks, I guess the louder smaller "pile" is good enough then
Two are good, four would be great. If I need more than that I'd switch drivers and get an FP14k.
Dan,Thanks, I guess the louder smaller "pile" is good enough then
Two are good, four would be great. If I need more than that I'd switch drivers and get an FP14k.
Doubling powered cabinets will get you about +7dB, an extra dB for directivity.
Adding a half sheet of plywood along each side your small pile will get you about +3 dB.
There is a lot more than a +4 dB price difference between the two options
.
Exactly, they come in for ~$900 USDCheaper alternative ???
Well if you only need two sheets of ply to build the box...Dan,
Doubling powered cabinets will get you about +7dB, an extra dB for directivity.
Adding a half sheet of plywood along each side your small pile will get you about +3 dB.
There is a lot more than a +4 dB price difference between the two options
And the width is = 1/2 sheet...
And the woofer is ~$125...
I say build as many as you care to move.
Sorry Art,
It seems I have missed your post. My word "little" was referring to the gain in the system by the enlarged 'End Correction' as result of using side reflectors. In other words, these reflectors make the (virtual) path length a little longer.
If the 'End Correction' agrees with your measurements is difficult to say since there are to many other acoustic influences involved.
(Btw, these amps wouldn't they be perfect for your B&C's?)
The debate remains a constant battle in my head. I could sell the 2 which are not in use and buy an appropriate 18" driver for Xoc1's 6 fold or weltersys' keystone, build 2 of either enclosure and purchase the 2nd driver immediately after selling another pair of 3015LFs. The debate comes in when i realize I can power 6 Kappalites with one amp. If you gents think i,ll be happier with the sound from the 2 18 inchers (first and formost, over my 2 T48s and 2 SS15s), then i'll just shut up and post these Kappalites for sale.
Hi Justin,
We all seem to agree that what you really want is not possible with 3015lf's. Even when the right concession are made, it still will run the 3015lf's excursion into the danger zone. The right 18"driver can offer what you really want and with reserves, so you don't have to worry about durability.
But you have to decide yourself.
We all seem to agree that what you really want is not possible with 3015lf's. Even when the right concession are made, it still will run the 3015lf's excursion into the danger zone. The right 18"driver can offer what you really want and with reserves, so you don't have to worry about durability.
But you have to decide yourself.
I was not unhappy with the sound of the 4015LF (probably a bit better speaker for a TH than the 3015LF) at lower drive levels in the Keystone, but the Lab 12s and the B&C18SW115 were much better sounding and louder at full power level.
You could build a pair of Keystones with bolt pattern for 18”, put a 15” to 18” adapter on, dump your present cabinets, then buy some BCSW118-4 with that money, then sell the last 3015LF.
Easy as that
.
You could also build a Cubo Sub 215. It would best be driven with up to 675 W per driver when using a 30 Hz, 24 dB/ octave high pass. Might want to put -3 dB at 63 Hz.
If you´re upgrading to 18" drivers in the future building 6 singles (of any design) would be better imo.
Best regards Johan
If you´re upgrading to 18" drivers in the future building 6 singles (of any design) would be better imo.
Best regards Johan
Like I stated in another post, I have purchased (6) 5x5 sheets of 3/4" 13 ply baltic birch. I also purchased a couple 4x8 sheets of OSB for a test box of Xoc1's Real 6 Fold TH. Martin (Xoc1) is working on a custom baffle (talked about in his TH-18 thread, specifically posts #482, 488 & 490) for this prototype.
I'm planning to use the B&C 18SW100 as they have pretty high xmax (12.5mm), have greater technology over the TBX series and will take 1700W without a problem; resulting in a calculated output of about 128dB after power compression.
Martin, was this plan intended to have the top board between the front & back or on top of the front & back boards? (red or green box below?)
I'm planning to use the B&C 18SW100 as they have pretty high xmax (12.5mm), have greater technology over the TBX series and will take 1700W without a problem; resulting in a calculated output of about 128dB after power compression.
Martin, was this plan intended to have the top board between the front & back or on top of the front & back boards? (red or green box below?)
