Attn: Experts, Sub1500's in a 4638 JBL cabinet

[LE15-Thumper]

Ok, to the guy's out there that own these. I put two of these in this box:
http://www.jblpro.com/pub/cinema/4638.pdf

With ports closed bass seems weak and rolled off. This seems to contradict what you guys have experienced with these. With one port closed. they seems to sound very good but don't seem to be damped enough as I get a lot of cone excursion. With both ports uncovered bass is quite boomy.

What am I doing wrong ? These cabs are tuned to 40Hz. What is the effective tuning with one port covered ?

I know that I need more power, I have 300 watts each driver at the moment, but even at lower volume levels, I don't get that nauseating extension that I remember from the B460.

[korgroenewoud]

Hello,

I own two of these sub1500''s. They are used in the factory-build cabinet TIK SUB. (with build-in amp) That is a closed cabinet of two cubic feet. In that cabinet they still have a huge cone-excursion. So i don't think these speakers can be used in a ported cabinet. Somebody on the forum can tell you the technical specifications of this super woofer. (Giskard can)
I am not a technician, but i think you use a totally wrong cabinet in which the woofers will be damaged.


Kor

[grumpy]

The T/S values I plugged into WinISD are probably not the latest/best, but you can
get an idea of why it would sound boomy if the 8ft3 box is tuned to 40... one port
plugged and a subsonic filter in place they should sound pretty good (tuning drops to
~28Hz)

unless you've got one wired backwards... or turntable feedback they should be
pretty well behaved excursion-wise up to quite a few hundred watts.

?:blink:

[Anthony L100]

Somebody on the forum can tell you the technical specifications of this super woofer. (Giskard can)
Kor


I have previously seen a link to the tech manual for the TIK Sub but it wouldn't work. Would you re-post it please Giskard? http://audioheritage.org/vbulletin/images/smilies/biggrin.gif

[4313B]

I no longer have it.

***

This is all I could find:

[4313B]

With ports closed bass seems weak and rolled off.What is your low pass filter set to?

[Anthony L100]

I no longer have it.


***

This is all I could find:

Thankyou.

[Anthony L100]

Hello,

I own two of these sub1500''s. They are used in the factory-build cabinet TIK SUB. (with build-in amp) That is a closed cabinet of two cubic feet. In that cabinet they still have a huge cone-excursion. So i don't think these speakers can be used in a ported cabinet. Somebody on the forum can tell you the technical specifications of this super woofer. (Giskard can)
I am not a technician, but i think you use a totally wrong cabinet in which the woofers will be damaged.


Kor

Hello Kor, do you have the Tik Sub or just the drivers? I would be interested to know your thoughts on the TiK Sub in a music application. Tony.

[korgroenewoud]

Hello Kor, do you have the Tik Sub or just the drivers? I would be interested to know your thoughts on the TiK Sub in a music application. Tony.

Hi Tony,

Well, i can tell you that i changed a year ago my B380 's driven by Crown DC 300 series II and BX 63 for two TIK subs with internal build-in amps. I only use them for music application and not for home theatre. I was really amazed what a huge deep bass these systems can perform. The cabinets are twice smaller then the B 380. These speakers you really feel. They only work till 30 Hz.(in my situation) Sometimes you dont hear them, and then suddenly the room starts shaking. You enter a strange atmosphere. My main system is the JBL S3100 MK II. They need these woofers, because they dont go as deep as the Tik subs. So for music application they are incredible.

P.S. Nice cat b.t.w.

[Anthony L100]

Thanks Kor, I also have one (just one!) TiK sub, but I think my listening room is too small to fully apreciate it's qualities. I also think I have phase issues as the switch to reverse phase does not really produce an obvious "in phase" result. I have read up the threads about sub placement and set up and come to the conclusion that the room is too small to let it "breathe" properly. If I turn the sub off, obviously I lose the extension but the bass from the main speakers is better defined and more pleasing generally. I guess I will have to move to a bigger house! I'm glad you confirmed that they are good for music application as I was wondering if they were designed with home theatre in mind primarily. I certainly agree with you regarding cone excursion, that's some amp in there!:bouncy: Perhaps the cat can hear something I can't, he loves extended listening sessions, but not with the TiK! Tony.

[Anthony L100]

So small...

[Anthony L100]

I don't get that nauseating extension that I remember from the B460.

Thumper, sorry to hijack your thread, but i'm desperately searching for that "NAUSEA":barf:

[LE15-Thumper]

What is your low pass filter set to?


"Low pass filter" as in the lower roll off point or boost point ?

I am using an Audio Control Richter Scale II with the Ultra low Boost ON and some EQ-ing (Cut / Downward) towards the crossover point. I find I have to cut the gain quite a bit between 63 and 125 hz. I guess maybe I am getting room gain augmenting the output of my LE15H's. If I run the EQ Flat there is way too much bass between 63 and 125Hz. I am guessing room gain is the culprit because this unit supposed to have at least an 18db per octave roll off. I am using the Richter Scale as the Xover as well. 80hz and above to the LE15A's and below to the 1500's of course.

Do I need a subsonic filter ? The R-S has one built in. I am using CD's, so rumble isn't the problem.

Thanks for the replies.