[kaigoss69]

Originally Posted by makkan00

Very interesting. I always thought that IB sub would die due to mechanical failure. But you pointed out that it is thermal failure which can cook the sub in IB installation.

I looked at your graphs. Couple of things are very intersting especially results for AE SPB 15. Also results for 12W7 are very promising...

As you simulated it in a big box and I wonder with the trunk + windows open (no resistance), would a driver reach its xmax that could lead to mechanical failure?
OR am I extra careful...?

I have tried to look at Pe rating for 12W7 but could not find it on their website....any idea? or Shall I consider its 1000W RMS as Pe?

There already is very little damping with the trunk volume simulated at 16 ft3. With the trunk open the xmax basically stays the same, and the output just drops a little. The program I believe assumes a true IB environment on the front side of the cone, so modeling windows up and down does not work.

When I smoked the VC on my sub yesterday I was using a 30Hz subsonic and the program calculated a max. excursion of 16 mm, which is also the sub's xmax, and I can vouch that the sub was playing linear at the time, so the program I think is very accurate and reliable for that. Your 12w7 has a Pe of 750W I believe so giving it 1000W could be problematic. If I were you I would do the JL gain setting technique in order to avoid sending it more than it can handle. My Infinity did not give me any audible warning before I smelled burnt metal and at that point the sub is already toast (pun intended) so be careful with that very expensive sub of yours! If you want to be extra safe I would say get a JL 750/1 amp, since that's all the power you're ever going to need anyway.

[kaigoss69]

Originally Posted by kaigoss69

There already is very little damping with the trunk volume simulated at 16 ft3. With the trunk open the xmax basically stays the same, and the output just drops a little. The program I believe assumes a true IB environment on the front side of the cone, so modeling windows up and down does not work.

When I smoked the VC on my sub yesterday I was using a 30Hz subsonic and the program calculated a max. excursion of 16 mm, which is also the sub's xmax, and I can vouch that the sub was playing linear at the time, so the program I think is very accurate and reliable for that. Your 12w7 has a Pe of 750W I believe so giving it 1000W could be problematic. If I were you I would do the JL gain setting technique in order to avoid sending it more than it can handle. My Infinity did not give me any audible warning before I smelled burnt metal and at that point the sub is already toast (pun intended) so be careful with that very expensive sub of yours! If you want to be extra safe I would say get a JL 750/1 amp, since that's all the power you're ever going to need anyway.

Actually, I just looked up the specs on the 12W7 again and the Pt (Pe) is 1000W so I'd say you're good! At 1000W, keeping the same 25Hz 4th order subsonic filter, your calculated xmax is 24 mm at 29Hz.

[makkan00]

Originally Posted by kaigoss69

Actually, I just looked up the specs on the 12W7 again and the Pt (Pe) is 1000W so I'd say you're good! At 1000W, keeping the same 25Hz 4th order subsonic filter, your calculated xmax is 24 mm at 29Hz.

Smashing Kaigoss.
Many thanks for reassuring the value of Pe.

From my experience, I guess I am running approx 750-800W with bass boost turned on. It already gets really loud, but I guess I will adjust the gains as per instructed.

[kaigoss69]

Originally Posted by makkan00

Smashing Kaigoss.
Many thanks for reassuring the value of Pe.

LOL I haven't heard that word used since "Goldmember".

Originally Posted by makkan00

From my experience, I guess I am running approx 750-800W with bass boost turned on. It already gets really loud, but I guess I will adjust the gains as per instructed.

Yes and leave bass boost at zero (HU & amp). Instead, turn the gain to the correct setting.

[makkan00]

Originally Posted by kaigoss69

LOL I haven't heard that word used since "Goldmember".

There you go and you heard it now

Originally Posted by kaigoss69

Yes and leave bass boost at zero (HU & amp). Instead, turn the gain to the correct setting.

One of the reason I am dispossing PDX 1.1000 as it does not have bass boost.
Lots of audiophiles are against bass boost on the amp, but I really love it especially when you have control over it in the cabin.
With different songs, I adjust it differently and if I turn it off....sound is flat (bass 0 on HU).

I guess I have to listen to you then

[mob17]

Makkan do you have a sub level control?

[makkan00]

Originally Posted by mob17

Makkan do you have a sub level control?

Mob
It is bass boost gain controller, one made by JL.
I have set my gains with bass boost at 80% so if I reduce that, sub becomes quiet.

[makkan00]

I have listened to this system for few days now...

Only one issue. Serious Voltage drop, despite of capacitor in the system and upgrading battery earth cable to 0AWG.
On full volume and with bass boost at 10db, amp turned off today

[taibanl]

Originally Posted by makkan00

I have listened to this system for few days now...

Only one issue. Serious Voltage drop, despite of capacitor in the system and upgrading battery earth cable to 0AWG.
On full volume and with bass boost at 10db, amp turned off today

What do you have your subsonic filter set at?

[makkan00]

Originally Posted by taibanl

What do you have your subsonic filter set at?

Taibanl
It is 30Hz with IB setup.

[kaigoss69]

I suspect your problem has to do with the efficiency of the w7. Look at the graphs I posted, the w7 was getting 1000w vs 500w for the others. 3 db higher means twice as loud. I don't have the program here now but I bet that with a true IB sub you could reach the same output on less than 1/3 the power.

[makkan00]

Originally Posted by kaigoss69

I suspect your problem has to do with the efficiency of the w7. Look at the graphs I posted, the w7 was getting 1000w vs 500w for the others. 3 db higher means twice as loud. I don't have the program here now but I bet that with a true IB sub you could reach the same output on less than 1/3 the power.

Kaigoss
I thought the input power was same for your graphs and I was very happy to see 12W7 doing best in 12 inch drivers.

Also looking at xmas graph, it had the max.

So did you compare 1000w input into JL vs 500w into other drivers?

Just read mob17's thread and even he is powering Fi IB3 with 800W approx which is way above PE rating for that sub.

I must also admit that my sub is setup with bass boost on nearly to 90% of its available range. I am thinking that it could be the reason that certain frequencies are getting boosted and reaching way above the rating of the sub or capacity of our cars---> leading to voltage drop?

[mob17]

So what's the Pe rating of the IB3 12?

[Mr Singh]

Originally Posted by mob17

So what's the Pe rating of the IB3 12?

There isn't one. 500wrms @ 20hz free air. Thats exactly how free-air drivers should be rated IMO.

Thermally it will handle twice that, with the same coil used in other Fi drivers known to take well over 20x that power in an SPL style 'burst' situation.

[kaigoss69]

Originally Posted by Mr Singh

There isn't one. 500wrms @ 20hz free air. Thats exactly how free-air drivers should be rated IMO.

Thermally it will handle twice that, with the same coil used in other Fi drivers known to take well over 20x that power in an SPL style 'burst' situation.

Let's stick with RMS, are you saying it'll handle 1000w thermally, and at 20hz (for those who like to listen to organ music) the power handling is limited by xmax?

[Mr Singh]

Originally Posted by kaigoss69

Let's stick with RMS, are you saying it'll handle 1000w thermally, and at 20hz (for those who like to listen to organ music) the power handling is limited by xmax?

Correct. Mechnically that is what an IB driver is most vunerable at, and that's how Fi rate there IB3 series.

[mob17]

My gains were set by MrSingh at optimum so roughly 870w. I have since had to turn this down on the amp and on the helix (-7dB). Its proving too much SPL for my front stage and my ears

I think i've fallen in love with the Fi. And thats without properly working on tuning the whole system yet.

[makkan00]

Originally Posted by Mr Singh

There isn't one. 500wrms @ 20hz free air. Thats exactly how free-air drivers should be rated IMO.

Thermally it will handle twice that, with the same coil used in other Fi drivers known to take well over 20x that power in an SPL style 'burst' situation.

Mr Singh
500w RMS, is that mechanical limit if you are saying thermally it will take twice of 500w RMS?

[makkan00]

I've scooped my Jl 1000/1 V2 today.
To my surprise, I was feeding my sub 1250W RMS.

And those signals are clean without clipping. As soon as I go above 1250W RMS or if I increase bass boost, amp starts clipping.