Starting a Clone Bassic15 Build

[svenyonson]

I'm building this as my larger/outdoor venue cabinet (double bass, jazz). Planning on integrating a BQ-500 amp by sculpting a channel on the back of the amp so that the amp is not in the cabinet space (mostly for overheating concerns)

Everything is cut, glueing up tomorrow.

Second photo is my existing amp/cabinet (MB-200) for smaller venues. Tigerwood slats for grill (will make the same for the big brother)

 

[KenD]

Very nice work Do the grill slats make the cab output any more directional than with a conventional cloth or steel mesh grill?

 

[John D Harris]

What 15" driver are you using?

 

[beans-on-toast]

Very nice. Do you have any concerns that the slats will vibrate like a string causing a buzz?

 

[BruceG68]

I'm curious too.What driver are you using and how did you decide on port size and length.Did you get info from the manufacturer of the driver to help you figure that out?

 

[svenyonson]

Very nice work Do the grill slats make the cab output any more directional than with a conventional cloth or steel mesh grill?

Thanks - I don't think so, but hard to quantify.

 

[svenyonson]

What 15" driver are you using?

Kappalite 3015

 

[svenyonson]

Very nice. Do you have any concerns that the slats will vibrate like a string causing a buzz?

Thanks - no buzz whatsoever. The tigerwood is very hard and everything is tightly fitted/glued/screws (grill is removable).

 

[svenyonson]

I'm curious too.What driver are you using and how did you decide on port size and length.Did you get info from the manufacturer of the driver to help you figure that out?

Ah, good questions. Kappalite 3015. The cabinet is 7 years old now, and it has been sealed until now. Wanted it to push more air, more volume. I didn't have a port sizing program so I decided to ask Gemini (AI) and give all of the parameters. (internal volume, speaker Q factor). The recommended ports were 2" x 12.1". I didn't have nearly that much depth available so asked if curved ports would work? (yes). So I picked up some 2" ABS pipe and two wide sweep elbows. Sounds great in my living room, still need a live test.

 

[svenyonson]

I'm curious too.What driver are you using and how did you decide on port size and length.Did you get info from the manufacturer of the driver to help you figure that out?

Oh, maybe you were asking about the Bassic15 build? There are other threads on TB for the Bassic15 (with a 3015), and the ports are 4" x 8". I'm committed to the 4" diameter, and when I am finishing it up I will recalculate the internal volume, and ask Gemini for a precise length for the tubes.

 

[BruceG68]

Cool sounds like you have done your homework and everything I see looks good.Have fun!

 

[agedhorse]

AI has returned absurdly incorrect results. AI is wrong or poor in about 1/2 the results.

I would believe the 2 x 4” ports 8” deep as much closer to reasonable.

 

[svenyonson]

AI has returned absurdly incorrect results. AI is wrong or poor in about 1/2 the results.

I would believe the 2 x 4” ports 8” deep as much closer to reasonable.

Yes, agree. The 2 x 2" ports 12.1" deep was for the smaller cabinet.

This was my query:

"I have a speaker cabinet with an internal volume of 1.2 cubic feet, allowing for the volume displacement of the driver. The driver is a 15" Eminence Kappalite 3015, with a Q rating of .34 and a resonant frequency of 41hz. Then internal depth of the enclosure is 8.5". If I use 2 port tubes, what is the optimal internal diameter and length for the port tubes?"

 

[meisi]

AI has returned absurdly incorrect results. AI is wrong or poor in about 1/2 the results.

I would believe the 2 x 4” ports 8” deep as much closer to reasonable.

There is an active thread out there on another popular forum for DIY tube amps. The poster is testing chatGPT circuits against humans proof readers.

Very amusing results. Depends on your definition of amusing, of course.

 

[CryingBass]

AI = Arse Insult

 

[Jim Nazium]

Nice work! But I want a lever to rotate those slats 90 degrees to cover the speaker during transport, then open up to play

 

[svenyonson]

Nice work! But I want a lever to rotate those slats 90 degrees to cover the speaker during transport, then open up to play

That is actually brilliant! I did actually make a sturdy cardboard case for it, which has worked great but is starting to get a bit long in the tooth..

 

[BruceG68]

Why don't you email Eminence and ask them.I built some 3 way PA speakers a few years ago using all Eminence drivers 15s,10s and horns.They told me how big and long the ports and the boxes sound great.Who would know their speakers better than them?

 

[svenyonson]

Why don't you email Eminence and ask them.I built some 3 way PA speakers a few years ago using all Eminence drivers 15s,10s and horns.They told me how big and long the ports and the boxes sound great.Who would know their speakers better than them?

Good idea. I did email them asking for some sample cabinet designs for their 3015, and they responded simply with a link to their products page and FAQ page. But I will ask them about the port lengths for the Bassic15. The smaller cabinet is already done and committed.

 

[Wasnex]

I did email them asking for some sample cabinet designs for their 3015, and they responded simply with a link to their products page and FAQ page.

AFAIK the box is way too small for the 3015.

Not sure if you are aware, but if you click the specifications tab on the product a page, a link is provided to a cab design doc. Here is the link: https://cdn.shopify.com/s/files/1/0270/8665/1462/files/Kappalite_3015_cab.pdf

The smallest ported design in the doc is 1.833 cu ft. It is obviously not intended for bass as a 100hz HPF is required.