Well, I'm feeling a little sick, thinking I sould have gotten more, but some of the rest of you (in the USA at least)should feel worse. The Lansing Heritage forum came through-I wish I had known of them earlier, Thanks Roddy!! I knew about the site, but not the forum.
Turns out that my JBL woofers are from 4 way monitor speakers sold in Asia: the 4344 Mk 2 . Balanced with aluminum shorting ring. The 4344-2 were introduced in about 1995 it appears, and the docs I got from a helpful guy were last revised in 2001. I think they are now discontinued. Battery biased crossover, very expensive. .
Turns out that my JBL woofers are from 4 way monitor speakers sold in Asia: the 4344 Mk 2 . Balanced with aluminum shorting ring. The 4344-2 were introduced in about 1995 it appears, and the docs I got from a helpful guy were last revised in 2001. I think they are now discontinued. Battery biased crossover, very expensive. .
I got more info, they seem to be more like true woofers in that their Fs is down in the low 30's. The are also "only" about 93 or 94 dB efficient. Since I want to use them below about 180 hz and bi-amped, I think I lucked out. Lest I be accused of being a total jerk, when I said the rest of you should feel sick I was referring to the fact that I offered to get you some too. I'm pretty grateful that I at least got 2 , which is plenty for my needs in truth. They are apparently highly damped so have precise but not generous bass, since they are made to sell in Japan. JBL does seem to make special models for Japan, ie the K2 was first only sold there.
Who knows, they might not be really that great but I have high hopes that they are better than my Selenium PA woofers (which didn't seem so bad to me until the crossover zone....
Who knows, they might not be really that great but I have high hopes that they are better than my Selenium PA woofers (which didn't seem so bad to me until the crossover zone....
Here's a link to further discusssions regarding the Radian coax's
and speakers based on the them
http://www.diyaudio.com/forums/showthread.php?s=&postid=268848
They are made by Galante Audio
and speakers based on the them
http://www.diyaudio.com/forums/showthread.php?s=&postid=268848
They are made by Galante Audio
Deltalite from Eminence
Eminence Deltalite 15" neo magnet, Fs, 41 97dB exactly what you want !!
http://editweb.iglou.com/eminence/eminence/pages/products02/neo/neo2515.htm
Eminence Deltalite 15" neo magnet, Fs, 41 97dB exactly what you want !!
http://editweb.iglou.com/eminence/eminence/pages/products02/neo/neo2515.htm
If you consult post #20 you will see that the Deltalite has been discussed.
If we ever ordered a custom speaker, I would think that the Deltalite would be what it would be based on. The frame is open,
the neo magnets are light and easy to ship and up to date,
The problem is that I have had a hard time modeling it so that it will get below 50 hz. in a reasonable sized cabinet Others seem to get similar results, although I'd love to hear more input by other people modeling it. Also from people who have actually heard it!!
If we ever ordered a custom speaker, I would think that the Deltalite would be what it would be based on. The frame is open,
the neo magnets are light and easy to ship and up to date,
The problem is that I have had a hard time modeling it so that it will get below 50 hz. in a reasonable sized cabinet Others seem to get similar results, although I'd love to hear more input by other people modeling it. Also from people who have actually heard it!!
maybe....
you could try using PiAlign software (free)
http://www.pispeakers.com/contents.html
I had exactly the same problem with the gamma 12, other programs modelled huge, but PiAlign gave me a nice neat size, and they work beautifully !!
you could try using PiAlign software (free)
http://www.pispeakers.com/contents.html
I had exactly the same problem with the gamma 12, other programs modelled huge, but PiAlign gave me a nice neat size, and they work beautifully !!
Speakers for ported boxes have signifigantly lower Qts than those designed for closed box use. A Qts below 0.38 is low and those above this figure is high. This indicates a large box for speakers with high Qts. If a small box is used then then the speaker should have high Qts with high damping. That's a bit tricky for the average constructor to get right.
The box size also depends on Vas of the driver parameters.
Eminence do several versions of 15 inchers with wild specs.
The Hi Per 427 Qts of 0,38 gets used alot here in power cabinets. The standard 427 has a Qts of 0,87. That is specifically intended for a car boot with piles of Cu volume.
rich
The box size also depends on Vas of the driver parameters.
Eminence do several versions of 15 inchers with wild specs.
The Hi Per 427 Qts of 0,38 gets used alot here in power cabinets. The standard 427 has a Qts of 0,87. That is specifically intended for a car boot with piles of Cu volume.
rich
here are some 15" JBL subs that might be great for open baffle:
http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=299-750&ctab=2
No T-S parameters though. Lots of x-max
They are 4 ohms so get 2 per channel to up the efficiency a bit!
http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=299-750&ctab=2
No T-S parameters though. Lots of x-max
They are 4 ohms so get 2 per channel to up the efficiency a bit!
Variac said:
You didn't look very hard... From the Parts Express website:
Power handling: 800 watts RMS/1500 watts max *VCdia: 4" *L1k: 1.55 mH *Impedance: 4 ohms *Re: 2.90 ohms *Frequency range: 25-500 Hz *Fs: 25 Hz *SPL: 92 dB 2.83V/1m *Vas: 4.52 cu. ft. *Qms: 4.90 *Qes: .34 *Qts: .32 *Xmax: 18 mm *Dimensions: A: 15-1/4", B: 14", C: 7".
Peace
open baffle jbl? expensive idea
Specifications: *Power handling: 800 watts RMS/1500 watts max *VCdia: 4" *L1k: 1.55 mH *Impedance: 4 ohms *Re: 2.90 ohms *Frequency range: 25-500 Hz *Fs: 25 Hz *SPL: 92 dB 2.83V/1m *Vas: 4.52 cu. ft. *Qms: 4.90 *Qes: .34 *Qts: .32 *Xmax: 18 mm *Dimensions: A: 15-1/4", B: 14", C: 7".
http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=299-750
Use higher q speakers for open baffles!
Specifications: *Power handling: 800 watts RMS/1500 watts max *VCdia: 4" *L1k: 1.55 mH *Impedance: 4 ohms *Re: 2.90 ohms *Frequency range: 25-500 Hz *Fs: 25 Hz *SPL: 92 dB 2.83V/1m *Vas: 4.52 cu. ft. *Qms: 4.90 *Qes: .34 *Qts: .32 *Xmax: 18 mm *Dimensions: A: 15-1/4", B: 14", C: 7".
http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=299-750
Use higher q speakers for open baffles!
OK OK I'm blind Sorry.
If you are willing to use equalization, then these will work even with low Q. AND they have the x-max to handle the equalized signal. Especially if you use 2 per channel as I suggested!!
4 would cost $1000, which is what some people around here spend for stuff. I can't though!
Shipping will kill you though!!
Mark
Sorry. If you are willing to use equalization, then these will work even with low Q. AND they have the x-max to handle the equalized signal. Especially if you use 2 per channel as I suggested!!
4 would cost $1000, which is what some people around here spend for stuff. I can't though!
Shipping will kill you though!!
Mark
Attachments
Hi mikee12345........that 15 incher
With Qts of 0.32 and Vas of 4.52, that should make an excellent reflex enclosure of B4 alignment with no peaks or dips,i.e 0dB flat.
My cals show fb=29Hz; f3=32Hz. Box size = 2.6Cuft.
This is for reflex.........for dynamite peformance use port size min 5" dia or space permitting 6 inch. The length of the port shouldn't be more than 2x port width and not extend more than half the depth of the box. A large port on the front should be some distance from the driver to avoid any upper frequency sound reflection through the port.
A larger box will lower system Qts; result in poorer bass and lower power handling.
A smaller box will raise the Q, and up goes the other freq parameters and will probably boom. Not worth the hassle...
....... a typ stage speaker.
Using this type frame in a closed box isn't on.
Hope this helps
rich
With Qts of 0.32 and Vas of 4.52, that should make an excellent reflex enclosure of B4 alignment with no peaks or dips,i.e 0dB flat.
My cals show fb=29Hz; f3=32Hz. Box size = 2.6Cuft.
This is for reflex.........for dynamite peformance use port size min 5" dia or space permitting 6 inch. The length of the port shouldn't be more than 2x port width and not extend more than half the depth of the box. A large port on the front should be some distance from the driver to avoid any upper frequency sound reflection through the port.
A larger box will lower system Qts; result in poorer bass and lower power handling.
A smaller box will raise the Q, and up goes the other freq parameters and will probably boom. Not worth the hassle...
....... a typ stage speaker.
Using this type frame in a closed box isn't on.
Hope this helps
rich
Why would a woofer be unfit for closed box operation? What about this one?: http://perso.wanadoo.fr/supravox/haut-parleurs/285 GMF.html
Another thing:
The Eminence Alpha 12 seems very nice for open baffle operation, plus it's cheap! ('bout 50 euro each) With 150 Wrms, 94 db (50 - 500 hz) and 2.9 mm Xmax only fit for home applications though.
I'm thinking of a couple of configs (in a, sort of, upgrade form):
# Alpha 12 (open baffle) + Tangband 871s (open baffle) (+some downEQ of the Alpha, or 2x/3x 871s)
- XO@~500 hz, 3rd order
~ 2 x 50 + 2 x 25 = 150 euro
# Alpha 12 (OB) + Supravox 135LB (closed)
- XO@~400 hz, 1st order
~ 2 x 50 + 2 x 115 = 330 euro
# Alpha 12 (OB) + Supravox 215 Signature Bicone (OB)
- XO@~150 hz, 1st order
~ 2 x 50 + 2 x 260 = 620 euro
Another thing:
The Eminence Alpha 12 seems very nice for open baffle operation, plus it's cheap! ('bout 50 euro each) With 150 Wrms, 94 db (50 - 500 hz) and 2.9 mm Xmax only fit for home applications though.
I'm thinking of a couple of configs (in a, sort of, upgrade form):
# Alpha 12 (open baffle) + Tangband 871s (open baffle) (+some downEQ of the Alpha, or 2x/3x 871s)
- XO@~500 hz, 3rd order
~ 2 x 50 + 2 x 25 = 150 euro
# Alpha 12 (OB) + Supravox 135LB (closed)
- XO@~400 hz, 1st order
~ 2 x 50 + 2 x 115 = 330 euro
# Alpha 12 (OB) + Supravox 215 Signature Bicone (OB)
- XO@~150 hz, 1st order
~ 2 x 50 + 2 x 260 = 620 euro
hi Nielsio....... I'm working on the other ones. You won't get far on the quality and performance by just putting any loudspeaker unit to a box without knowing the characteristics. Some are designed specifically for closed box and others for reflex loading, and perhaps others. Trying to keep this simple,
Loudspeaker units for reflex loading have deliberately low Qts below 0.38 with also low Vas....if you shove a speaker unit with a low Qts into a closed box then for the fb and response to reach 0dB or slight + will result in a seriously restricted low frequency response. To get the design right, it requires Qts;Ls resonance fig and speaker compliance parameters to <fit> a particular unit to a box.
If one tries to fit a speaker specifically designed for closed box into a reflex loading box, it may not like it and may sound dreadful with very poor bass...overdamped...with a low Q. This implies large boxes for speakers with high Qts. Speakers for car boot have high Vas and high Qts, there is enough Cubic area to satisfy both parameters.
Fitting a high Qts speaker into a HiFi box will sound dreadful and have a very high uncontrolled Q. Controlling the Q isn't quite so easy....so much depends on surroundings and acoustics.
Have a look at this site: www.wilmslowaudio.com; may persuade you to head for a kit.....
I don't know what your application is.....looks like Hi Fi, ?Are you more interested in closed box apps ?
285GMF this one ain't too bad....B4 alignment at 5Cuft;
fb=47Hz;f3=47Hz. This unit would be good for a French Juke Box. Sound better than the JBL but look at the power handling!
There are better units for the deepest bass. The double impedance peak in a well tuned reflex will extend the response lower than fb. There are other problems and I can deal with them later.
The 135 is a midrange unit.
Try to select units; bass-mid-upper with equal reference sensitivities i.e SpL 90dB/m
rich
Loudspeaker units for reflex loading have deliberately low Qts below 0.38 with also low Vas....if you shove a speaker unit with a low Qts into a closed box then for the fb and response to reach 0dB or slight + will result in a seriously restricted low frequency response. To get the design right, it requires Qts;Ls resonance fig and speaker compliance parameters to <fit> a particular unit to a box.
If one tries to fit a speaker specifically designed for closed box into a reflex loading box, it may not like it and may sound dreadful with very poor bass...overdamped...with a low Q. This implies large boxes for speakers with high Qts. Speakers for car boot have high Vas and high Qts, there is enough Cubic area to satisfy both parameters.
Fitting a high Qts speaker into a HiFi box will sound dreadful and have a very high uncontrolled Q. Controlling the Q isn't quite so easy....so much depends on surroundings and acoustics.
Have a look at this site: www.wilmslowaudio.com; may persuade you to head for a kit.....
I don't know what your application is.....looks like Hi Fi, ?Are you more interested in closed box apps ?
285GMF this one ain't too bad....B4 alignment at 5Cuft;
fb=47Hz;f3=47Hz. This unit would be good for a French Juke Box. Sound better than the JBL but look at the power handling!
There are better units for the deepest bass. The double impedance peak in a well tuned reflex will extend the response lower than fb. There are other problems and I can deal with them later.
The 135 is a midrange unit.
Try to select units; bass-mid-upper with equal reference sensitivities i.e SpL 90dB/m
rich
You're misunderstanding me quite a bit.
My application is home-hifi. The type of speaker I'm trying to create is for friends / family.
I'm not looking for the deepest bass, sorry for confusing you.
I read your remark on a driver not being fit for closed box operation. This got me interested, since I have the 285 GMF and am thinking of putting it in a closed box. The qts seems right for it, considering your remarks on that.
Actually it's a wideband unit; just like the Tangband and the Supravox 215 SB.
The Supravox 135, 215 SB and Eminence Alpha 12 all have (very near) equal sensitivity. The Tangbands do not, but that config is the most budget one, and compromises on the consequences of the sensitivity-differences.
Right now I have it in an open baffle config, with XO@300hz-1st to Jordan JX92s (open baffle) + Behringer Ultracurve EQ. I have not had any power-limitations whatsoever.
My consideration is to put the 285 in a closed box, and replace the Jordan with the Supravox 215 SB, since both original drivers aren't fit for open baffle (qts not near 0.7). After this, I think I'll only EQ the 285 (room modes + make it go lower).
My application is home-hifi. The type of speaker I'm trying to create is for friends / family.
I'm not looking for the deepest bass, sorry for confusing you.
I read your remark on a driver not being fit for closed box operation. This got me interested, since I have the 285 GMF and am thinking of putting it in a closed box. The qts seems right for it, considering your remarks on that.
Actually it's a wideband unit; just like the Tangband and the Supravox 215 SB.
The Supravox 135, 215 SB and Eminence Alpha 12 all have (very near) equal sensitivity. The Tangbands do not, but that config is the most budget one, and compromises on the consequences of the sensitivity-differences.
Right now I have it in an open baffle config, with XO@300hz-1st to Jordan JX92s (open baffle) + Behringer Ultracurve EQ. I have not had any power-limitations whatsoever.
My consideration is to put the 285 in a closed box, and replace the Jordan with the Supravox 215 SB, since both original drivers aren't fit for open baffle (qts not near 0.7). After this, I think I'll only EQ the 285 (room modes + make it go lower).
Hi there......Fitting the 285 into a closed box won’t work ....this speaker isn’t designed for closed box use. I’ll show you....
I get the following figures:
Vb =5 Cuft sized box; system Q = 0.55.......way too low....poor very thin bass and waste of speaker capability. f3 = 93Hz way way too high. (f3 = begin LF cutoff freq)
If I pump in Vb = 3 Cuft sized box, syst Q = 0.62 still too low. f3 = 88.6Hz.
If I pump in Vb = 2 Cuft sized box, syst Q = 0.72 (not for rock music). f3 = 87Hz.
(Cuft to litres x 28.27)
Classical music buffs like sys Q less than 1. The bass won’t be prominent.
For all round types of music; a sys Q of 1, and most modern speakers trend for somewhat boomy Q of 1.4. This last one is quite popular and will give prominent bass. A 2 cu ft cabinet is really too small for a 15 incher.
rich
I get the following figures:
Vb =5 Cuft sized box; system Q = 0.55.......way too low....poor very thin bass and waste of speaker capability. f3 = 93Hz way way too high. (f3 = begin LF cutoff freq)
If I pump in Vb = 3 Cuft sized box, syst Q = 0.62 still too low. f3 = 88.6Hz.
If I pump in Vb = 2 Cuft sized box, syst Q = 0.72 (not for rock music). f3 = 87Hz.
(Cuft to litres x 28.27)
Classical music buffs like sys Q less than 1. The bass won’t be prominent.
For all round types of music; a sys Q of 1, and most modern speakers trend for somewhat boomy Q of 1.4. This last one is quite popular and will give prominent bass. A 2 cu ft cabinet is really too small for a 15 incher.
rich
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