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[Phil Lewandowski]

Silas Pradetto wrote on Thu, 29 July 2010 06:57

That would be 4 watts then, making that graph look not nearly as impressive since it would be 6dB high

Still an average of about 106dB from 35-100hz, with a -3dB point of 33-34hz and -10dB point of about 28hz, sounds like a pretty nice sub to me.  

Since it is in a single and is a regular horn sub I would imagine you will see that lower part of the pass-band start to creep up closer to the sensitivity of the 70hz+ region, like with the LABsub.



It would be interesting to get a measurement of the LABsub with 2.83v overlaid to see how 2 same size subs designed by the same person compare.


Take Care!
Phil

[Marjan Milosevic]

Hmmm, i would really like to know what is going on inside that horn. Neither the horn length not the mouth size will indicate such a response. Some nice voodoo there

[Art Welter]

Marjan Milosevic wrote on Thu, 29 July 2010 14:53

Hmmm, i would really like to know what is going on inside that horn. Neither the horn length not the mouth size will indicate such a response. Some nice voodoo there

At my first look at the response, I thought the same thing as you.
But looking closer, a simple “U” bend on each side of the DB 218  would result in about a 90 inch path length (7.5 feet). Straight horns can work pretty well to a quarter wavelength, 7.5 x4 =30 feet. Speed of sound is about 1130 feet per second, 1130/30=37.66 Hz, which looks to be very close to where the DB 218 starts rolling off.

Compare that to the pair of my “C horns” (top trace), which have about a 65 inch path length (5.4 feet). A pair of “C horns has a mouth area only slightly larger than the DB 218, 8.28  compared to 7.03 square feet.
5.4x4=21.6, 1130/21.6 =52.31 Hz, you can see that is also close to the low corner .

Art Welter

[Marjan Milosevic]

The box is 45x45 so path length can not be 90.
Exclude the size of the driver and cut that in half. So at least 10inch less. So 80 inch will be more accurate.
Not that this is not a long horn, and the acoustic loading does not stop sharp at the horn end, just it looks quite common FLH box. Not something i would expect from Danley.
A reshaped CV box .

[John Chiara]

And not even a category for it on the website?

[Art Welter]

Marjan Milosevic wrote on Fri, 30 July 2010 04:33

The box is 45x45 so path length can not be 90. Exclude the size of the driver and cut that in half. So at least 10inch less. So 80 inch will be more accurate. Not that this is not a long horn, and the acoustic loading does not stop sharp at the horn end, just it looks quite common FLH box. Not something i would expect from Danley. A reshaped CV box .

The horn path on the left drawing of a 45 x45 cabinet is longer than 90 inches, you can verify with a piece of paper, using the 45 inch sides for a measuring stick.
Another bend near the throat could make the horn another 20 inches longer still.
Considering the speaker door position, another bend is more likely than my crude drawing.



The horn path on the right is 44.25 inches.  Back in the 1970’s and 1980’s we were OK with trading some LF for “punch”,  this type of cabinet was very popular. I made my larger, square version after hearing of the similar Martin cabinet knocking plaster off the ceiling of a theater during Supertramp’s sound check.

Danley is all about offering cabinets that fit specific applications, and looking at the response, it looks like the DB 218  certainly will fit many . The very flat upper phase response may also compliment a higher crossover point than the tapped horns.

Art Welter

[Silas Pradetto]

Art Welter wrote on Fri, 30 July 2010 15:05

Marjan Milosevic wrote on Fri, 30 July 2010 04:33 The box is 45x45 so path length can not be 90. Exclude the size of the driver and cut that in half. So at least 10inch less. So 80 inch will be more accurate. Not that this is not a long horn, and the acoustic loading does not stop sharp at the horn end, just it looks quite common FLH box. Not something i would expect from Danley. A reshaped CV box . The horn path on the left drawing of a 45 x45 cabinet is longer than 90 inches, you can verify with a piece of paper, using the 45 inch sides for a measuring stick. Another bend near the throat could make the horn another 20 inches longer still. Considering the speaker door position, another bend is more likely than my crude drawing. The horn path on the right is 44.25 inches.  Back in the 1970’s and 1980’s we were OK with trading some LF for “punch”,  this type of cabinet was very popular. I made my larger, square version after hearing of the similar Martin cabinet knocking plaster off the ceiling of a theater during Supertramp’s sound check. Danley is all about offering cabinets that fit specific applications, and looking at the response, it looks like the DB 218  certainly will fit many . The very flat upper phase response may also compliment a higher crossover point than the tapped horns. Art Welter

If the left picture is accurate (which it looks pretty close), then they could make a half of a DBH218 and call it the DBH118. Much easier to transport, and still would couple into the equivalent of a DBH218, right?

Edit: but it's still nowhere near the path length of a LAB?

[Marjan Milosevic]

Art Welter wrote on Fri, 30 July 2010 21:05

Marjan Milosevic wrote on Fri, 30 July 2010 04:33 The box is 45x45 so path length can not be 90. Exclude the size of the driver and cut that in half. So at least 10inch less. So 80 inch will be more accurate. Not that this is not a long horn, and the acoustic loading does not stop sharp at the horn end, just it looks quite common FLH box. Not something i would expect from Danley. A reshaped CV box . The horn path on the left drawing of a 45 x45 cabinet is longer than 90 inches, you can verify with a piece of paper, using the 45 inch sides for a measuring stick. Another bend near the throat could make the horn another 20 inches longer still. Considering the speaker door position, another bend is more likely than my crude drawing. The horn path on the right is 44.25 inches.  Back in the 1970’s and 1980’s we were OK with trading some LF for “punch”,  this type of cabinet was very popular. I made my larger, square version after hearing of the similar Martin cabinet knocking plaster off the ceiling of a theater during Supertramp’s sound check. Danley is all about offering cabinets that fit specific applications, and looking at the response, it looks like the DB 218  certainly will fit many . The very flat upper phase response may also compliment a higher crossover point than the tapped horns. Art Welter

Yes you are right.
However not a very complex box.

[Marjan Milosevic]

Silas Pradetto wrote on Fri, 30 July 2010 21:11

Art Welter wrote on Fri, 30 July 2010 15:05 Marjan Milosevic wrote on Fri, 30 July 2010 04:33 The box is 45x45 so path length can not be 90. Exclude the size of the driver and cut that in half. So at least 10inch less. So 80 inch will be more accurate. Not that this is not a long horn, and the acoustic loading does not stop sharp at the horn end, just it looks quite common FLH box. Not something i would expect from Danley. A reshaped CV box . The horn path on the left drawing of a 45 x45 cabinet is longer than 90 inches, you can verify with a piece of paper, using the 45 inch sides for a measuring stick. Another bend near the throat could make the horn another 20 inches longer still. Considering the speaker door position, another bend is more likely than my crude drawing. The horn path on the right is 44.25 inches.  Back in the 1970’s and 1980’s we were OK with trading some LF for “punch”,  this type of cabinet was very popular. I made my larger, square version after hearing of the similar Martin cabinet knocking plaster off the ceiling of a theater during Supertramp’s sound check. Danley is all about offering cabinets that fit specific applications, and looking at the response, it looks like the DB 218  certainly will fit many . The very flat upper phase response may also compliment a higher crossover point than the tapped horns. Art Welter If the left picture is accurate (which it looks pretty close), then they could make a half of a DBH218 and call it the DBH118. Much easier to transport, and still would couple into the equivalent of a DBH218, right? Edit: but it's still nowhere near the path length of a LAB?

+1 on both your points.

[Art Welter]

Silas Pradetto wrote on Fri, 30 July 2010 13:11

Art Welter wrote on Fri, 30 July 2010 15:05 Marjan Milosevic wrote on Fri, 30 July 2010 04:33 The box is 45x45 so path length can not be 90. Exclude the size of the driver and cut that in half. So at least 10inch less. So 80 inch will be more accurate. Not that this is not a long horn, and the acoustic loading does not stop sharp at the horn end, just it looks quite common FLH box. Not something i would expect from Danley. A reshaped CV box . The horn path on the left drawing of a 45 x45 cabinet is longer than 90 inches, you can verify with a piece of paper, using the 45 inch sides for a measuring stick. Another bend near the throat could make the horn another 20 inches longer still. Considering the speaker door position, another bend is more likely than my crude drawing. The horn path on the right is 44.25 inches.  Back in the 1970’s and 1980’s we were OK with trading some LF for “punch”,  this type of cabinet was very popular. I made my larger, square version after hearing of the similar Martin cabinet knocking plaster off the ceiling of a theater during Supertramp’s sound check. Danley is all about offering cabinets that fit specific applications, and looking at the response, it looks like the DB 218  certainly will fit many . The very flat upper phase response may also compliment a higher crossover point than the tapped horns. Art Welter If the left picture is accurate (which it looks pretty close), then they could make a half of a DBH218 and call it the DBH118. Much easier to transport, and still would couple into the equivalent of a DBH218, right? Edit: but it's still nowhere near the path length of a LAB?

The DBH-218 could be split, but then the pair would weigh more, and cost more, double the connectors, double the wheels. A customer that can deal with a 45” depth is not likely to mind it being large anyway.

If the DBH-218 horn is like I drew it, it would be about an 8 foot path, the LAB Sub is about 9 feet.
9x4=36,1130/36=31.38 Hz, which from your tests is very close to the LAB Sub LF corner when multiples are used.

If the DBH-218 has the  kind of an initial flare in the picture below, it would be longer than the LAB Sub, and the low corner would move down lower than the LAB Sub in multiples.

The 18” speakers have much more displacement and power handling than the Lab 12”, so the DBH-218 should have lots more output from the same size cabinet.

As you said before, a LAB killer.

Art Welter