Yep, all of that is understood. I'd need to adjust the set back to I'd say 1.25" for a half inch frame, a half inch frame standoff piece and the grill cloth. But more to the question, most longer grills such as the 8x10 you referenced have a stabilizing piece of wood that runs through the center inbetween speakers. However in this 2x15 design, that stabilizer bar would cover the ports. Would it be better to have two cross pieces that cross the drivers opposed to the ports? Or would it be best to redesign slightly and go to 4 ports all on the side a la a dually design?
Enjoy the benefits of a premium membership!
Upgrade Account
-
TalkBass has been independent since 1998. Add your voice.
Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
Join free Log in
Want zero display ads or expanded classifieds tools? Compare plans.
Custom DIY 2x15 cab build
- Thread starter johnk_10
- Start date
Yep, all of that is understood. I'd need to adjust the set back to I'd say 1.25" for a half inch frame, a half inch frame standoff piece and the grill cloth. But more to the question, most longer grills such as the 8x10 you referenced have a stabilizing piece of wood that runs through the center inbetween speakers. However in this 2x15 design, that stabilizer bar would cover the ports. Would it be better to have two cross pieces that cross the drivers opposed to the ports? Or would it be best to redesign slightly and go to 4 ports all on the side a la a dually design?
Ampeg had a 215 cabinet with a cross member across the center of each speaker. I asked Jess Oliver about this since it was also used on the B-15 cabinet. He said that it was structural and it didn't affect the speaker performance. I thought that maybe it served as a high frequency dispersion aid, a beam blocker.
You wouldn't want to cover the ports. Moving the ports as you said is an option. This is where you would haveto get creative. One option is to place triangles in each corner to strengthen the frame. Another option would be to place more standoffs around the frame, better supporting it. Plywood was used on the 810. If it is stick built, a hard wood such as poplar could be used. Perhaps a metal grille covered with cloth would work well.
This is where design options and second guessing starts to tug on you.
This is the grille fastener that many vintage cabinets used: Invalid Link Removed. There are many similar products available.
You wouldn't want to cover the ports. Moving the ports as you said is an option. This is where you would haveto get creative. One option is to place triangles in each corner to strengthen the frame. Another option would be to place more standoffs around the frame, better supporting it. Plywood was used on the 810. If it is stick built, a hard wood such as poplar could be used. Perhaps a metal grille covered with cloth would work well.
This is where design options and second guessing starts to tug on you.
This is the grille fastener that many vintage cabinets used: Invalid Link Removed. There are many similar products available.
So I'd thought about doing that and having two cross beams for support, having them go across the speakers in some way. I was worried it would affect the sound. However, I did some research and mockups, and I think I am going to shift the speaker and the ports and do it dually style with the speakers skewed to the right side of the box (looking at it from the front) and replacing two 4" ID 3.9" long ports with 4 2.5" ID 4 1/8" long ports to achieve the same tuning. that will give me a single cross beam no blocking or covering anything. Thanks for your help.
Yes, I like the dually. The two center ports could be spread apart a bit more: [Invalid or Expired Link Removed]
@kbakerde
I have been planning to build a 2x15 to match my mid seventies Ampeg V4. I have the drivers, hardware, tolex and grill cloth... I just need to find the time.
I plan to have a shelf brace between the drivers which necessitated rearranging the ports. I am planning to provide a center brace in the grill frame.
I went with four 4" diameter ports (I can't remember their length offhand). The baffle is recessed 1 1/4". I have included a link to my sketch below. The lighter lineweight indicates the grill frame. I can provide more detailed plans and my Bassbox Pro analysis if you are interested.
2x15 Sketch.pdf
I have been planning to build a 2x15 to match my mid seventies Ampeg V4. I have the drivers, hardware, tolex and grill cloth... I just need to find the time.
I plan to have a shelf brace between the drivers which necessitated rearranging the ports. I am planning to provide a center brace in the grill frame.
I went with four 4" diameter ports (I can't remember their length offhand). The baffle is recessed 1 1/4". I have included a link to my sketch below. The lighter lineweight indicates the grill frame. I can provide more detailed plans and my Bassbox Pro analysis if you are interested.
2x15 Sketch.pdf
Once I get to putting mine together I'll start a whole new thread. What are the external dimensions you are using for your cabinet? Since you are putting a shelf in you are treating each chamber separately correct?
The box I'm going for is going to be tuned at about 44 hz, and I'll be using 2x 3015's for mine.
External dimensions are 26 3/4" wide to match the Ampeg V4, 40" high, and 16" deep. It's a little big, but that's OK.
The shelf in mine is intended solely for bracing the front and rear baffles together and I was planning cut out a pair of large holes in it. I don't think there any acoustic advantages of having speakers in separate chambers assuming drivers are well matched.
I'll be using a pair of Faital 15PR400's. I don't remember my chosen tuning frequency. I'll check my models when I get home.
I'm debating building a pair of single 15 cabinets as well. It would certainly be more portable, but there's something about the look of a single large cab. I've had modular arrangements in the past and always wound up using the full stack, resulting in a few extra pieces to bring. It'll especially look awesome since the guitarist in my band is using my 68 Fender Bassman and matching 2x15, which is also 40" high.
Honestly, I had a Dually made for me about 2 Christmases ago to pair with my old Acoustic 370 (A pricey combo but one I kinda miss, longs story) I think moving a 2x15 on a set of tilt back casters is much easier than moving 2 1x15's. I've had a fearful 15/6, 12/6 Cube, a pair of Aggie 1x12's and I've got a Avatar 2x12 that's not terribly heavy. I think a well sized 2x15 is a fantastically portable cabinet.
John
I will be trying to build one of these - thank you for this post.
My question, is the 14" deep inside box dimension or the outside dimension.
Thank you
Lennyj
- Feb 16, 2008
- 21,240
- 23,633
- Disclosures
- John K Custom Basses
so it sounds like, to me.. smaller chamber dictates larger port(s) makes sense, i rekon. as yall'z can see the v-4 thing is no stranger to me...
Reviving the zombie thread....
I’ve been wanting to build this 215 cab for 5 years and finally got around to it.
I just need to finish the grill using Ampeg black/silver grill cloth.
I’ve been wanting to build this 215 cab for 5 years and finally got around to it.
I just need to finish the grill using Ampeg black/silver grill cloth.
Looks great! Which speakers did you use?
I used the 3015s. I took advantage of Parts Express coupons.
So far at low volume it sounds pretty similar to the Genz 212 sitting next to it. The 215 has more mid presence, which I wanted, and surprisingly I don’t miss having tweeter at all. For my needs the highs are well represented. I’m sure it will get better once the speakers are broken in.
So far at low volume it sounds pretty similar to the Genz 212 sitting next to it. The 215 has more mid presence, which I wanted, and surprisingly I don’t miss having tweeter at all. For my needs the highs are well represented. I’m sure it will get better once the speakers are broken in.
I’ll post the weight when I’m done. I used 1/2x1/2 pine in the corners to be safe since I wanted a 3/8 roundover. Mine will be more than what JohnK weighed his at. It’s surprisingly light for a 215 cab.
there we go, nice.. u can see it better in this one, the other is a little dark to see.. p
