adding a second port to a 2x10

[JES]

Hi There,

I'm just doing a reality check before I cut into a speaker box.

I have an old Flite 2x10, which I'd like to re-fit to Eminence Basslite S2010 neo speakers, to make it even lighter.

It's a lightweight composite 2x10 (with tweeter, always rolled off) for bass guitar. Dimensions are 23" tall, 15" wide and 15" deep. It has one 3" diameter tubular port, 8" deep. The speakers now are some old Electro-Voice model.

I spoke with Al at US speaker who said the box is on the small side and tuned a little high, and I would do well to cut another 3" tubular port to 1.875" depth.

Does this make sense? I just thought it would be wise to get a second opinion before I started drilling.

Thanks.

 

[Bassmec]

Hi There,

I'm just doing a reality check before I cut into a speaker box.

I have an old Flite 2x10, which I'd like to re-fit to Eminence Basslite S2010 neo speakers, to make it even lighter.

It's a lightweight composite 2x10 (with tweeter, always rolled off) for bass guitar. Dimensions are 23" tall, 15" wide and 15" deep. It has one 3" diameter tubular port, 8" deep. The speakers now are some old Electro-Voice model.

I spoke with Al at US speaker who said the box is on the small side and tuned a little high, and I would do well to cut another 3" tubular port to 1.875" depth.

Does this make sense? I just thought it would be wise to get a second opinion before I started drilling.

Thanks.

I would get hold of the Thiel small params for the speakers you intend using and model them in your cabinet with software.
what's wrong with the Electrovoice drivers that's in it, apart from weight?.

 

[JES]

Thanks for the quick reply. Weight is the only issue, really (apart from not loving the tweeter, which I turn off). I'm pretty sure Al at US Speaker just inputted all my stats into the software, along with the Eminence specs (since we don't know for the E-Vs) and that's where the port suggestion came from.

Another option is to sell this one and my old 1x15, and buy new stuff. But even though I could afford it, this is way cheaper and I'm slightly sentimental about my cabs.

 

[Arjank]

Dimensions are 23" tall, 15" wide and 15" deep. It has one 3" diameter tubular port, 8" deep.

I spoke with Al at US speaker who said the box is on the small side and tuned a little high, and I would do well to cut another 3" tubular port to 1.875" depth.

Does this make sense?

No, it doesn't

Some math.
The cab is approx 55-60liters, if the tube is 3" in diameter and 8" long the tuning will be around 30hz. So IMO the tuning is way to low.
Adding a 2nd tube with the same lenght and diamter the tuning will be approx 41hz, that's a lot better but still fairly low. If you reduce the tubes to approx 5" the tuning will be approx 48hz which will be much better.
The cab's volume will be ok for two S2010 drivers, it's not to small.

Btw. if you can't cut the tube to 5" you'll have to add two extra tubes(3"/8") to get the tuning to approx 48-50hz.

 

[JES]

Thanks for the reply. Very helpful.

With the current too-low tuning, what are my issues? Just that the speakers will fart out at low volumes? And is there a way to adjust the single port or do I really need a second one?

--JES

 

[Arjank]

With the current too-low tuning, what are my issues? Just that the speakers will fart out at low volumes? And is there a way to adjust the single port or do I really need a second one?

--JES

It won't fart out at low volumes. The current tuning doesn't add the output in the correct frequencyrange that's suited for bassguitar.

If you stick with one 3" port you need to cut it down to a lenght of 1" to achieve a tuning of approx 48hz in that volume of approx 57liters.
The drawback of using only one tube is that you'll definitely get port-chuffing at higher volumes cuz the airvelocity gets to high.

 

[JES]

Thanks -- that's super helpful!