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Post by subjungle on Aug 11, 2012 7:48:42 GMT -7
Hi guys, I'm a n00b go easy pls  So a lower Qts might be better to make the bass a bit tighter, as per the Qts page And the Vas being 106 litres means I'll need a cubic meter of enclosure to get an IB effect Unfortunately I live in a rental, so I can't modify walls/ceilings etc so I need to build a box to get the IB bass! So, are these specs good for a IB application? Audio Specifications Sensitivity (2.83V@1m) 96dB Peak Power 1200W Nominal Impedance 4 ohms Power Handling (RMS) 300W Power Handling (Peak) 1200W Frequency Response 20Hz – 400Hz Woofer Specifications Suspension Compliance (Cms – ?m/N) 102 Voice Inductance 1kHz (Levc – mH) 2.42 Driver Radiating Area (Sd – in2/cm2) 132.5/855 Electrical Q (Qes) 0.76 Free-Air Resonance (Fs – Hz) 27.3 Maximum Excursion (Xmax –in/mm) .57/14.5 Total Q (Qts) 0.67 Mechanical Q (Qms) 5.7 Voice Coil Height (Hvc – in/mm) 1.45/37 Compliance Volume (Vas – ft3 / l) 3.76/106.5 Voice Coil DC Resistance (Revc – ohms) 3.63 Magnetic Gap Height (Hag – in/mm) .31/8 Motor Force Factor (Bl – Tm) 16.53 Dimensions External Diameter (in) 15-7/16 External Diameter (mm) 391 Mounting Cutout Diameter (in) 14 Mounting Cutout Diameter (mm) 355 Mounting Depth (in) 7-5/16 Mounting Depth (mm) 185 Thanks, Matt. |
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Post by ThomasW on Aug 21, 2012 6:28:49 GMT -7
Always a good idea to mention things like living in Oz when asking questions like this .......
Some people in Europe have used these when no other drivers were available. The Xmax is low so multiples are needed for IB use.
I wouldn't use them in a sealed box since the Qtc and Fs are relatively high and the Xmax is low.
What other drivers do you have access to?
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Post by subjungle on Aug 23, 2012 7:19:10 GMT -7
OK an update, a little progress so far yes, I live in Oz, we don't seem to have very good access to reasonable drivers at reasonable prices, things that you might get in the USA for $300 typically cost $500 here, just in general. I can't find any of the drivers typically mentioned on this site, I think they are more USA domestic rather than USA international if you get what I mean (small target audience). I've been in talks with a seller, and I'm getting a good deal on 8 of these 15" JBL puppies (see opening post), this gives a volumetric displacement (2*Xmax*Sd) of 20 litres. The seller does have another 6... it's so tempting...  In the future, I will use it as an infinite baffle. For now I'm going to hook it up in open baffle, with 2 manifolds having 4 subs each. The manifolds will sit either side of my TV. A few questions, to make bass tight you want an amplifier with a high damping factor? So the EP4000 has a damping factor of >300 at 8 Ohms. I have a QSC which probably isn't powerful enough at only 500W per channel, but it has a damping factor of over 500... Will one EP4000 be enough? I think it is because I'm in a rental and I share a common wall with my neighbour, and that wall happens to be in my lounge room (open space theatre room)... |
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Post by FOH on Aug 23, 2012 8:06:47 GMT -7
A few questions, to make bass tight you want an amplifier with a high damping factor? ..... ..... Will one EP4000 be enough? I think it is because I'm in a rental and I share a common wall with my neighbour, and that wall happens to be in my lounge room (open space theatre room)... Damping factor, well typically you can throw a mfrs damping factor rating out the window. That said, sure, .. an amps control over cone movement is of paramount concern. I feel thinking one could determine that from specs (especially from Behringer ) may be wishful thinking. Many feel DF spec is important, conventional wisdom says otherwise, but the savvy user would speculate there may be more to it,... just sayin'. Now, most importantly, a rental? "(8)JBL drivers" and "rental" used in the same sentence would be contra-indicated.  Personally, I couldn't imagine playback level restrictions any more than what I already have, and our closest neighbors are maybe 100 feet (30m) away! Best of luck (btw; there is something odd about the damping factor of Behringer's EP series amps. I've noticed it, others I spoke with have to. Within it's normal operational range, which is quite powerful, it has superb control over cone movement. However it appears as if in certain clipping/overload conditions, the DF essentially goes to zero, and the cone control is entirely lost resulting in this case-hard bottoming. Quite bizarre really, still a steal.) |
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Post by tinnears on Aug 23, 2012 11:14:17 GMT -7
Filtering through all I've read about amplifier damping factor...
1. About half of all folks think it's very important. The other half don't.
2. Speaker wires affect the amplifier's damping ability so, for subwoofers, keep your speaker wires as short as practicable, the same length and large gauge.
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Post by face76 on Feb 26, 2013 18:14:40 GMT -7
The GT5-15 will work in a slot loaded or ripole configuration. At 1 meter.  Half meter, slightly less power. In it's test enclosure.  |
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JBL GT5-15
Sept 6, 2013 10:43:43 GMT -7
via mobile
Post by subjungle on Sept 6, 2013 10:43:43 GMT -7
The GT5-15 will work in a slot loaded or ripole configuration. At 1 meter. Half meter, slightly less power. In it's test enclosure. Wow test results! I have 8 of these subs, and in the last month I just moved into my first home so now I can do something with them! Can anyone comment on those test results, namely in comparison to other 18" driver options? |
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Post by FOH on Sept 9, 2013 8:34:31 GMT -7
Wow test results! I have 8 of these subs, and in the last month I just moved into my first home so now I can do something with them! Can anyone comment on those test results, namely in comparison to other 18" driver options? Can't apply much from those tests for your potential usage really. I'd say if you had 8 of these, you could get good results in an IB. Now how deep and how loud will all depend on your situation. Care must be taken regarding amplification, EQ'ing/filtering, etc. |
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jcnes
New Member
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Post by jcnes on Nov 10, 2013 14:05:20 GMT -7
subjungle, I did a build with 8 of these drivers 3 or so years ago. They worked out quite well for me, though I don't have another frame of reference, as mine is the only IB install I've ever heard. Anyway, here's my build thread, with measurements. Regarding your QSC amp; assuming it's an honest-to-goodness 500wpc rms @ 4ohms, I'm not sure how much more you'd need for these drivers. They're very efficient, and if you run 4 of them in a series/parallel arrangement to each channel, they're even more so. I'm pretty sure one EP4000 would be way, WAY more than enough. I run all 8 drivers with a Tapco amp (a subsidiary of Mackie which is sadly no longer around) that's similar in power to the EP4000, and I don't think I've ever even come close to the limits of that amp. I don't listen to music that loud, though, so if you're looking for 110db levels, or if you have to EQ in a lot of boost to compensate for deficiencies in your room setup, disregard everything I just said. But if it were me, I'd save my money and invest in a feedback destroyer and an SPL meter, and spring for the big amp down the road. EQ'ing my install really helped me a lot. Thomas is right about the low Xmax, but you've got 8 of them, and 20 liters is 20 liters. That's a good bit of displacement for your average living room. Anyway, good luck my friend. Let us know how your progress goes! |
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Post by kiwijunglist on Dec 13, 2016 14:29:53 GMT -7
Hi I have 4x JBL GTO-1514D ( specs) and iNuke 3000dsp. The 1514D is almost the same as the GT5-15. Fs 24.9 Hz / Vas 161 L / Qes 0.51 / Qts 0.47 / Xmax 14.5mm / 350W RMS (1400 peak) Was originally for a ported or sealed box, however we just bought a house and I'm thinking of going IB instead because large boxes are not suitable for the new living space. The IB would have to be in the ceiling, either as a single manifold or dual manifolds. Subjungle - Did you build your IB, got a link? Thanks Kiwi |
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Post by subjungle on Dec 26, 2016 5:52:29 GMT -7
Hi I have 4x JBL GTO-1514D ( specs) and iNuke 3000dsp. The 1514D is almost the same as the GT5-15. Fs 24.9 Hz / Vas 161 L / Qes 0.51 / Qts 0.47 / Xmax 14.5mm / 350W RMS (1400 peak) Was originally for a ported or sealed box, however we just bought a house and I'm thinking of going IB instead because large boxes are not suitable for the new living space. The IB would have to be in the ceiling, either as a single manifold or dual manifolds. Subjungle - Did you build your IB, got a link? Thanks Kiwi Sorry mate i didn't get to building it, have moved house twice since then and the 8 boxes keep following me around In about a year or 18 months i might hv a place to put them. If you do something with them then be sure to document it for the rest of us |
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