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View Full Version : 4 x sub 1500 in sealed, 2 x vented sub 1500 or 2 x 2242 for more fysical bass?!



Kalle
12-28-2013, 03:24 AM
Hi!

I have 2 sub 1500 in 2,5 cu ft boxes. I like the sound of them but I would like a little more fysical bass att lover spl and a little more punch overall. Some more spl @ max is not bad either.

I`m thinking of 3 alternatives.

1: build vented boxes for my 2 sub 1500

2: buy 2 more sub 1500 and put them in 2,5 cu ft boxes and have total 4 of them.

3: build 2 x 4645c (or s1) with 2242

High sound quaility at all sound levels are required and I like to feel the music.
The room is quite small so it gives some boost in the lowest frequencies.

As fronts i use LSR 32.

Any suggestions:)?

Regards Karl

pos
12-28-2013, 03:57 AM
Hi Kalle,

As for the lack of punch at low SPL, this is probably related to Fletcher-Munson curves and loudness compensation: do not hesitate to boost low frequencies a little bit more when listening at low SPL. Going ported or doubling the number of drivers will not help there.

Lee in Montreal
12-29-2013, 03:17 PM
Hi Kalle,

As for the lack of punch at low SPL, this is probably related to Fletcher-Munson curves and loudness compensation: do not hesitate to boost low frequencies a little bit more when listening at low SPL. Going ported or doubling the number of drivers will not help there.

I too think a little eq is needed to get that physical punch. Also, we must know how you define "punch". Sub 40Hz shake, or 100Hz kick in the stomach (which the JBL 4530 was famous for).

Also, how are the 1500 driven? How much power to feed them? Digital crossover?

Mr. Widget
12-29-2013, 05:28 PM
The Sub1500 in a 5 cu ft box tuned to 20Hz will give you about 10dB greater output below 35Hz than the sealed box will. However as Lee points out this is additional shake not punch. Punch is in the 80Hz to 150Hz region. The relatively light coned PA type drivers tend to excel at this.


Widget

Kalle
12-30-2013, 03:31 AM
Hi all!

Pos: I`we done som EQ and it is possible to get things shaking. But only at higher spls I think. Mabye it is something with room an placement. Or mabye I have demands that is not possible to fulfill.

Lee: I have a LAB 2002 amp limited to 680rms. (Capable of 1500) I cross them with a behringer ultradrive HP 20hz 12db, LP 80hz 24db. Now I give them a boost at 25hz with 5db.

Widget: Mabye I should test vented boxes for them and see what I like best.

Earlier I had a JBL 4719 (2x2241) fronts with 2x2206 2447 and 2405 and they of course had more punch witch I liked. But the sub 1500 and lsr 32 sounds much better. But lacks the energy of the "PA" system (of course).

I tried to do some simulations on the sub 1500 in Win isd pro but I can`t find all parameters. For example sd. Any idea where to find it?


I have to admit that I like that PA punch. I actually had 4530`s many years ago when playing as a dj and I loved them:) I understand that sub 1500 won`t give me that and that is ok. (now I have a party rig with 4x 18" scoops and jbl dual 2204 + 1" in my garage for that. A childs dream for a 32 years old man:o:)

/Karl

pos
12-30-2013, 04:44 AM
Pos: I`we done som EQ and it is possible to get things shaking. But only at higher spls I think. Mabye it is something with room an placement. Or mabye I have demands that is not possible to fulfill.
Shacking things requires SPL indeed... or furnitures with loose screws :D

Lee in Montreal
12-30-2013, 06:36 AM
Hi Kalle

The Sub1500 would probably feel much better in a bigger vented cabinet as Widget suggested.

But before anything else, be aware that a 12db high pass filter at 20Hz will cut frequencies up to 40Hz+. If I were you, I would experiment with a 48db HP filter at 20Hz. Or just for testing, no high pass, but be carefull with volume. Also, try setting your low pass filter at 24db @ 100Hz to get more punch. I beileve your problem is mainly because of the wrong filtering settings.

Lee in Montreal
12-30-2013, 08:04 AM
Specifications
- Frequency range: 25-500 Hz
- Power handling: 800 watts RMS/1500 watts max
- VCdia: 4"
- Impedance: 4 ohms
- SPL: 92 dB 2.83V/1m

T/S
- Vas: 4.52 cu. ft. / 128 litre
- Qes: .34 Qms: 4.90
- Qts: .32
- Re: 2.90 ohms
- Fs: 25 Hz
- Le : 1.55 mH
- Xmax: 18 mm

Dimensions
- Overall Diameter: 15-1/4"
- Cutout Diameter: 14"
- Mounting Depth: 7".

I made some simulations and 5cft tuned to 25Hz works great. But 6cft tuned to 22Hz goes even lower. Even under 600watts, you have plenty of excursion left.

Lee in Montreal
12-30-2013, 08:38 AM
http://img.photobucket.com/albums/v668/Lee_Vuong/JBL parts factory/Sub1500_response_zps8b0c65db.jpg

http://img.photobucket.com/albums/v668/Lee_Vuong/JBL parts factory/Sub1500_excursion_zpsea869af7.jpg

Kalle
12-30-2013, 09:32 AM
http://img.photobucket.com/albums/v668/Lee_Vuong/JBL parts factory/Sub1500_response_zps8b0c65db.jpg

http://img.photobucket.com/albums/v668/Lee_Vuong/JBL parts factory/Sub1500_excursion_zpsea869af7.jpg

Thanks:). I`m new in simulating and did not sucsess to get cone excursion for the sub 1500 in win isd. At what watts is the cone excursion simulation above? Do you have any curve at max spl?

/Kalle

Mr. Widget
12-30-2013, 10:14 AM
I made some simulations and 5cft tuned to 25Hz works great. But 6cft tuned to 22Hz goes even lower. Even under 600watts, you have plenty of excursion left.I have real world experience with 5 cu ft at 20Hz... this works very well with a pair pounding a very large room with 600 watts per woofer. They will unload below tuning frequency and care should be taken or a high pass filter employed.


Widget

Lee in Montreal
12-30-2013, 01:21 PM
When modelizing, I found that tuning to 20Hz reduces a lot the 30-40Hz region. It's basically about deciding where to compromize :bouncy:

Mr. Widget
12-30-2013, 03:08 PM
When modelizing, I found that tuning to 20Hz reduces a lot the 30-40Hz region. It's basically about deciding where to compromize :bouncy:I'm not familiar with your modeling software, but it is probably simulating an anechoic environment. With the sub sitting on the floor and near a wall in my room the response was quite flat.


Widget

Lee in Montreal
12-30-2013, 03:23 PM
5 cubic feet enclosure
Tuned to 25Hz (red line) vs 20Hz (blue line)
Green line shows gains and losses between both tunes.

http://img.photobucket.com/albums/v668/Lee_Vuong/JBL parts factory/Sub1500_25vs20Hz_zps72619b13.jpg