Bazooka Tube 8" or Solobaric SL8 for bass

[audiolife 5,000+ posts]

1 cft + port displacement. my friend has 1 in a prefab box (l78 ported) and it sounds like a pretty solid 12 on 500 watts

 

[DejaWiz 5,000+ posts]

The Kicker manual states this on ported boxes for the Kicker S8L5 and L7...

VentedSPL/DeepBass: 1 cf + 2" x 9.5" x 21.25" port (.234 cf). Box needs to be 1.234 cf total (this includes port volume).

2 * 9.5 = 19 sq-in

19 / 3.14 = 6.051

Round Port = about 6" diameter and 21.25" long.

This is just a rough estimate. You'll probably want to fiddle with WinISD.

 

[Flyhalf 10+ year member]

I looked at the JL audio 8w6. It seems a little pricey. $235. I could get a SL78 for about half of that as well as a cmp8. Do you think the JL 8 would be that much better than those?

 

[DejaWiz 5,000+ posts]

Nope. Any of those in the right enclosure is going to sound great for an 8".

And for that price you could definitely get 2 S8L5's and maybe 2 S8L7's.

 

[Flyhalf 10+ year member]

The Kicker manual states this on ported boxes for the Kicker S8L5 and L7...
VentedSPL/DeepBass: 1 cf + 2" x 9.5" x 21.25" port (.234 cf). Box needs to be 1.234 cf total (this includes port volume).

2 * 9.5 = 19 sq-in

19 / 3.14 = 6.051

Round Port = about 6" diameter and 21.25" long.

This is just a rough estimate. You'll probably want to fiddle with WinISD.

The problem I would have with this is the port length. I only have about 14.5" of total box depth to use.

When I was trying to figure the port for the 1 cu/ft box I just made, I originally thought about a 3" pvc port. With that, tuned to 45.5 hrtz, the length would have been 7". When I changed to 2" pvc for the port, the length chaged to 2.8".

Could I use a 2" or 3" port and have it sound good? I assume that would lessen the port length from 21.25" to something workable for my situation.

 

[DejaWiz 5,000+ posts]

The problem I would have with this is the port length. I only have about 14.5" of total box depth to use.
When I was trying to figure the port for the 1 cu/ft box I just made, I originally thought about a 3" pvc port. With that, tuned to 45.5 hrtz, the length would have been 7". When I changed to 2" pvc for the port, the length chaged to 2.8".

Could I use a 2" or 3" port and have it sound good? I assume that would lessen the port length from 21.25" to something workable for my situation.

You can run part of the port outside the box, or just use bends inside.

I would be careful using a smaller diameter port than what's recommended. You'll get a higher air velocity and it'll start panpiping on you, which would really sound like crapola.

 

[Flyhalf 10+ year member]

That's a cool idea. I've never thought about running the port outside of the box.

 

[DejaWiz 5,000+ posts]

That's a cool idea. I've never thought about running the port outside of the box.

Yeah, with some subs, they just need a long port. And this is def one way to circumvent having to build a box which would have rather large external proportions with a rectangular integrated port.

 

[Flyhalf 10+ year member]

OK, here's my new problem (good problem to have). I put that Kenwood 10" in the ported 1 cu/ft box tuned to 45.5 hrtz. and it sounds really good. It sounds much better than 2 of these did in a sealed box which surprises me. Not boomy at all, low, deep bass. Low notes sound awesome.

Does anyone think that a higher end line of 8" (rl-i8, CMP, Solobaric, etc.) would sound better in a .5-1.0 cu/ft ported box than my Kenwood 10". Right now I'm only giving the 10" about 220 Watts RMS with my Alpine MRP-M450. If I go down to 2 ohm I can extract 400 Watts RMS from the amp. That's what I have to work with and can't go anything larger box wise than 1.0 cu/ft. I'd also like to stick with a round port design (easier for me to build).

What do you guys think...

 

[DejaWiz 5,000+ posts]

I'd say that it's all in the install and what you are after. Try to hit up some local audio shops and listen to various configurations.

Can you tuned that box a bit lower than 45.5 Hz? Seems a bit high to me, unless that is your preference and goal. If not, then aim for about 32-35 Hz. Be sure to use a infrasonic filter (or a HP that is at least 18 if not 24dB/O) that's set to about 10 Hz lower than tuning frequency of the box. Let us know what you think of the difference.

 

[Flyhalf 10+ year member]

I tried to build a ported box based upon Kenwoods specs. It called for 1 cube ported at 45hz. I could easily try something lower and will. My amp has the HP filter. Is 10hz lower than box tuning rule of thumb?

 

[DejaWiz 5,000+ posts]

Generally, yes. It's a good starting point.

You really don't want your sub to work much below the port tuning level, as this can really cut it's lifespan short.

 

[Flyhalf 10+ year member]

I appreciate the help DejaWiz...

 

[DejaWiz 5,000+ posts]

Anytime

 

[Flyhalf 10+ year member]

Well this is what I've got so far and here are some install pics. Overall, I'm very happy with the sound. As usual though, I have to wonder if I couldn't get more out of this box with a different sub.

This was the first ported box I've built. The goal is to have low-deep bass, with moderate to good SQ while still maintaining the functionality of my rear seats.

I was originally thinking I would have to go with an 8" of some type in order maintain size requirements. But, this is a 1 cu/ft box which is probably about as large as I can go.