• Please note that there are a few updates and clarifications made in the Audiokarma Rules, mostly relating to advertising and the addition of the new "Paying it Forward" & "Giving back" forums in the AudioKarma Audio Marketplace section.

Old school auto 6x9's in ported or sealed enclosure?

Zolton

Zolton

Well-Known Member
Long story short...

I have some old school JBL 6 x 9 inch triaxial car speakers in boxes that I power via a "just as old" Alpine car amp and deck. I use it as a work shop system.

I'm in the process of refurbishing the speakers and am wondering if they should be put in a sealed or ported enclosure?

Is there a rule of thumb for older automotive speakers or is that too vague and it depends on the speakers specs.
 
Register to hide this ad
I installed some some Rockford Fosgate separates in seal boxes. My thinking was since car woofers are "free air" their suspension is stout to keep from bottoming. Meaning not much cone movement. Meaning they would work in small sealed boxes because they wouldn't compress much air. Easier than figuring port size/length without knowing xmas value.
 

Attachments

  • 100_4149.jpg
    100_4149.jpg
    69.3 KB · Views: 58
  • 100_4150.jpg
    100_4150.jpg
    46.8 KB · Views: 35
PioneerGuy75 said:
Bigger box is better for those....Those little 6x9 boxes the auto parts stores sell are way too small!!
Click to expand...

The boxes they are currently in I built myself many moons ago and are not the ones of which you speak.

The question was ported or sealed.

I suppose the 6x9's were meant to be mounted in the back window of a car and have the trunk as a cabinet. Which was both sealed (sort of) and huge.

edit; I was typing this as the above post was being posted.
 
So...I suppose they would be best mounted in very large sealed boxes.

Well that won't work out too well for my situation.

Sigh.:sigh:
 
My Son had a set of those and we built a 18x8x8 box using a 1x8 board. It was just a quick see if it works deal. We put 2 1/2" foam rubber along the inside and sealed the boxes with silicone.

My son used a 50watt per channel amp and I think he used a kenwood radio up front. It was fun and pretty impressive for what it was.
 
Those 6X9's would probably sing in a nice Transmission Line. Since they probably have a rather stiff suspension and they tend to play in a large (almost like a infinite baffle) airspace behind it the TL's may just be the ticket.
 
Zolton, 6 x 9 speakers were technically designed to be mounted on a rear deck with the trunk being the enclosure. They actually become IB, infinite Baffle speakers at that point. Generally speaking, IB speakers when used in an enclosure perform better in a sealed box. Without the thiele small parameters for your specific drivers it's a guess as to what volume enclosure you need.

With that said, the relatively small pre-made boxes for 6 x 9 speakers always worked well for me many years ago. My suggestion is to use the enclosures you made since you've already got them, and recommend keeping them sealed.
 
These old speakers are JBL TL-900's

I really have no info on them except they are 4 ohm, handle 100 watts and have a sensitivity rating of 93dB. That's it.

The boxes they are in are 20 inches high by 10 inches wide by 8.5 inches deep, so the internal volume is 1,100 cubic inches. Probably nowhere near big enough but bigger than the average 6x9 off the shelf box.

They are currently ported (and don't sound bad actually) but it was a shot in the dark attempt from back in the day.

I'll seal them up and give them a whirl. No harm in trying.:thmbsp:
 
1.5 cubic feet worked for me for years using the jensen 6 x 9`s with whizzer cones, excellent results with minimal effort two of my favorite things!
 
That's a fair bit larger than this box.

1.5 cubic feet is 2,592 cubic inches I do believe
 
Last edited:
I put my kicker D-9 6x9s in the small wedge shaped type closed boxes and powered them with a very clean japanese made alpine mrv300 and they sounded fantasticccc, tight accurate and super FAST I loved em.

as zultron said no harm in trying both open and closed.
 
You might putting them in whatever size boxes you have but leaving the back open. This results in a sorta open baffle. This gives you some bass but not the boxy sound of a small enclosure. If you like lean tight bass, this could be just the ticket.
 
U-234 said:
I installed some some Rockford Fosgate separates in seal boxes. My thinking was since car woofers are "free air" their suspension is stout to keep from bottoming. Meaning not much cone movement. Meaning they would work in small sealed boxes because they wouldn't compress much air. Easier than figuring port size/length without knowing xmas value.
Click to expand...

You are correct, the suspension is stiffer to limit bottoming in free air (infinite baffle). But, in too small an enclosure they may produce little bass output because of that limited enclosure compliance. With enough power behind them the cones will move plenty in a car though. Some contemporary 6x9 speakers can produce astonishing amounts of bass there. To retain that capability however there needs to be at least the minimum enclosure volume that allows them to do it.

So much for the theory, the reality is they may work just fine in a small enclosure. You really won't know until you try them out or measure the woofer and develop TS parameters for it. My gut says that older JBL car 6x9s were probably developed with rear deck mounting in mind and that would mean they may work best in a bigger enclosure of at least 1.0 cubic feet sealed. Or, maybe not...carry on!
 
You must log in or register to reply here.
Back
Top Bottom