Discussion split from pictures - Page 4

navin · 4th June 2007, 04:25 AM

Quote:

Originally posted by lazenna

What woofers for 2x15" bass do you guys recommend.

Prefer cast baskets.I am thinking about the Dayton rs15".
http://www.partsexpress.com/pe/pshow...number=295-468

Quote:

Originally posted by v-bro
Hi Lazenna, I think a great choice!
Don't let anybody tell you they aren't!

1. what makes a woofer a good choice for dipole? I mean what do we look for? Qms? Qts? Fs? Any guidelines?
2. That Dayton woofer looks well made but how ouwld it compare to old favs like the NHT1259, Bhrama, Shiva, Tumult or any of the drivers from Eminence (Kappa 15), Selenium (SLF 15), or even pro drivers like the JBL 2235 or Peavey low rider/pro rider subs.

v-bro · 4th June 2007, 03:32 PM

I think if there's enough surface you don't need optimal Q. As long as you have suffiecient hub and surface anything will work, I think preferrably high Qms and Qes.

Allthoug my 'pro' seventies JBL 2220A have very low Qts and work quite nicely in a medium sized room and pretty large baffle (with sides) and the baffle placed in contact with the floor.

ashok · 22nd June 2007, 05:41 AM

Can a maths expert tell us what happens to Qts and spl figures if we change a cone with another one with knowm mass , surface area and (expected ) resonance frequency ?

If you ask why , it's to guess what will happen if we graft a bigger cone on to a smaller frame. Say an 18 inch cone on to a 12 inch frame with various mods to the frame.
Qts should go up and Fs should fall , possibly Qms should go down. Sensitivity would suffer most I think.

Outlandish ... yes ! The web is full of far more outlandish things !

lazenna · 30th June 2007, 03:26 PM

Trying to narrow down my search for bass drivers going by experience or specs which would seem to be better? Ficar audio SSD18

DUAL 1 | DUAL 2

Fs: 24.7 Hz | 24.3 Hz
Re: 0.75 Ohms/coil | 1.5 Ohms/coil
Qms: 4.88 | 4.96
Qes: .75 | .69
Qts: .65 | .61
Mms: 296g | 308g
Cms: 0.14mm/N | 0.14mm/N
Sd: 1210cm^2 | 1210cm^2
Vas: 285 l | 285 l
Spl: 89.4dB 1W/1m | 89.6dB 1W/1m
Bl: 9.3 N/A | 14.1 N/A
Xmax: 21mm
Rms: 800W
Sealed box: N/A cuft
Ported box: 6-10 cuft @ 33Hz
Sub OD: 18.500”
Cut ID: 16.750”
Mounting depth: 9.500”
Displacement: 0.22cuft

Product code: 01918

Price: $ 239.00
*shipping is included

Power Handling: 800 watts RMS

Sensitivity: 89db (2.83 volts)

Impedance: 4 Ohm Nominal (SVC)

Dimensions

Outside Diameter: 46.2cm (18 3/16")

Mounting Diameter: 42.4cm (16 11/16")

Depth: 24.8cm (9 3/4")

Recommended Box Sizes

Sealed: 130 litres (4.6 cu. ft.)

Ported: 200 litres (7 cu. ft.) 19Hz tuning

EBS: 350 litres (12.4 cu. ft.) 15Hz tuning

Mach5 audio IXL-18.4
T/S Parameters

Fs = 17.7 Hz

Re = 3.4 Ohms

Qes = 0.39

Qms = 5.59

Qts = 0.37

Mms = 434.3 grams

Rms = 8.69 kg/s

Cms = 0.184 mm/N

VAS = 274.1 litres

Sd = 1029.2 cm2

Xmax = 22 mm

Cone Diameter = 36.2 cm

$210.00

v-bro · 30th June 2007, 04:26 PM

They all seem not to excel much in sensitivity which I think gives you less margin to play with correction. On the other hand they all have very high powerhandling, which means you can regain the margin by using a larger amplifier.

The DUAL 1 seems like the best choice...

lazenna · 2nd July 2007, 03:05 PM

What about these Ciare 18" model 18.00NdW1 price** $210.00
weight 6.3 Kg vc size 100mm
size 18" Fs 29hz
power handling 500W (AES) Bl (Wb/m) 24.85
Vas (M3) 0.29643 Sd(M2) .115209
SPL 1w1m 100.5dB Qms 12.36
Xmax 7mm* Qes 0.32
Frequency 30hz-1khz Qts 0.31
magnetic induction (T) 1.2

v-bro · 2nd July 2007, 05:30 PM

The 18.00ndw1 has a pretty nasty peak between 1 and 2 Khz. This is not a very big problem, but you can't get away with a simple 6db/oct filter....to say the least....

Furthermore they traded excursion for sensitivity, which is not a bad thing given the fact the woofer is BIG. The low resonance frequency comes in very nice.

Conclusion: It can work, but it needs a bit more effort....

v-bro · 2nd July 2007, 07:09 PM

Ciare 18.75 NdW seems more suitable....

peterbrorsson · 3rd November 2007, 05:03 PM

Here is an extreme dipole. I've no experience with ob but will have in the future. Like the bass from ob!

http://www.rauna.com/slides/speakerwalljpg.html

v-bro · 9th November 2007, 12:18 PM

It looks like the designer frequently kills mosquitos with a bazooka

sure it will rock the planet, but I could think of a few possible or theoretical flaws there...

By the way with the way they're place they're hardly OB, they rather use the corners of the room as enclosure...

22nd June 2007, 05:41 AM	#33
ashok diyAudio Member Join Date: Jun 2002 Location: 3RS	Can a maths expert tell us what happens to Qts and spl figures if we change a cone with another one with knowm mass , surface area and (expected ) resonance frequency ? If you ask why , it's to guess what will happen if we graft a bigger cone on to a smaller frame. Say an 18 inch cone on to a 12 inch frame with various mods to the frame. Qts should go up and Fs should fall , possibly Qms should go down. Sensitivity would suffer most I think. Outlandish ... yes ! The web is full of far more outlandish things ! __________________ AM

30th June 2007, 04:26 PM	#35
v-bro diyAudio Member Join Date: May 2006	They all seem not to excel much in sensitivity which I think gives you less margin to play with correction. On the other hand they all have very high powerhandling, which means you can regain the margin by using a larger amplifier. The DUAL 1 seems like the best choice... __________________ Max. cone displacement can be several foot on any speaker!Too bad it can be done only once......

9th November 2007, 12:18 PM	#40
v-bro diyAudio Member Join Date: May 2006	It looks like the designer frequently kills mosquitos with a bazooka sure it will rock the planet, but I could think of a few possible or theoretical flaws there... By the way with the way they're place they're hardly OB, they rather use the corners of the room as enclosure... __________________ Max. cone displacement can be several foot on any speaker!Too bad it can be done only once......

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4th June 2007, 03:32 PM	#32
v-bro diyAudio Member Join Date: May 2006	I think if there's enough surface you don't need optimal Q. As long as you have suffiecient hub and surface anything will work, I think preferrably high Qms and Qes. Allthoug my 'pro' seventies JBL 2220A have very low Qts and work quite nicely in a medium sized room and pretty large baffle (with sides) and the baffle placed in contact with the floor.

30th June 2007, 03:26 PM	#34
lazenna diyAudio Member Join Date: May 2007	Trying to narrow down my search for bass drivers going by experience or specs which would seem to be better? Ficar audio SSD18 DUAL 1 \| DUAL 2 Fs: 24.7 Hz \| 24.3 Hz Re: 0.75 Ohms/coil \| 1.5 Ohms/coil Qms: 4.88 \| 4.96 Qes: .75 \| .69 Qts: .65 \| .61 Mms: 296g \| 308g Cms: 0.14mm/N \| 0.14mm/N Sd: 1210cm^2 \| 1210cm^2 Vas: 285 l \| 285 l Spl: 89.4dB 1W/1m \| 89.6dB 1W/1m Bl: 9.3 N/A \| 14.1 N/A Xmax: 21mm Rms: 800W Sealed box: N/A cuft Ported box: 6-10 cuft @ 33Hz Sub OD: 18.500” Cut ID: 16.750” Mounting depth: 9.500” Displacement: 0.22cuft Product code: 01918 Price: $ 239.00 *shipping is included Power Handling: 800 watts RMS Sensitivity: 89db (2.83 volts) Impedance: 4 Ohm Nominal (SVC) Dimensions Outside Diameter: 46.2cm (18 3/16") Mounting Diameter: 42.4cm (16 11/16") Depth: 24.8cm (9 3/4") Recommended Box Sizes Sealed: 130 litres (4.6 cu. ft.) Ported: 200 litres (7 cu. ft.) 19Hz tuning EBS: 350 litres (12.4 cu. ft.) 15Hz tuning Mach5 audio IXL-18.4 T/S Parameters Fs = 17.7 Hz Re = 3.4 Ohms Qes = 0.39 Qms = 5.59 Qts = 0.37 Mms = 434.3 grams Rms = 8.69 kg/s Cms = 0.184 mm/N VAS = 274.1 litres Sd = 1029.2 cm2 Xmax = 22 mm Cone Diameter = 36.2 cm $210.00

2nd July 2007, 03:05 PM	#36
lazenna diyAudio Member Join Date: May 2007	What about these Ciare 18" model 18.00NdW1 price** $210.00 weight 6.3 Kg vc size 100mm size 18" Fs 29hz power handling 500W (AES) Bl (Wb/m) 24.85 Vas (M3) 0.29643 Sd(M2) .115209 SPL 1w1m 100.5dB Qms 12.36 Xmax 7mm* Qes 0.32 Frequency 30hz-1khz Qts 0.31 magnetic induction (T) 1.2

2nd July 2007, 05:30 PM	#37
v-bro diyAudio Member Join Date: May 2006	The 18.00ndw1 has a pretty nasty peak between 1 and 2 Khz. This is not a very big problem, but you can't get away with a simple 6db/oct filter....to say the least.... Furthermore they traded excursion for sensitivity, which is not a bad thing given the fact the woofer is BIG. The low resonance frequency comes in very nice. Conclusion: It can work, but it needs a bit more effort....

2nd July 2007, 07:09 PM	#38
v-bro diyAudio Member Join Date: May 2006	Ciare 18.75 NdW seems more suitable....

3rd November 2007, 05:03 PM	#39
peterbrorsson diyAudio Member Join Date: Jan 2006 Location: Cz Rep.	Here is an extreme dipole. I've no experience with ob but will have in the future. Like the bass from ob! http://www.rauna.com/slides/speakerwalljpg.html

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