Buck Box Designs - Refreshed Thread

[Slo_Ride]

Says the dude who can’t get Trumps dick out of his mouth

 

[Buck]

I am still healing from my back injury. I'm doing significantly better, but I'm going to have to wait a while longer to ensure I don't re-injure it. It stinks for me and whoever wants a design, but if I hurt this worse, I'll be out for a very long time.

 

[Buck]

Just if anyone wants to know. I have multiple chronic illnesses that have largely ruined my life, from a career standpoint. I have a severe neurological and immune system illness where it causes my connective tissue to crush my entire body. If I didn't have this connective tissue problem, my back wouldn't be injured. I'm in a constant literal tug of war with my own body. It literally consumes about half of my day-time, all of the time, even when I'm in the best shape I can be.

I can still answer questions and help people choose equipment and stuff like I usually do; I just do not have the back health and strength to sit for long periods of time to design. I'm going to be largely bed ridden until this heals enough to stop sending nerve pains into my legs and until my lower back tissue is somewhat softer than a concrete wall. I'm still here for system help, just can't design atm without making my situation worse. So, lmk if you need system building advice!

 

[Buck]

Back in the day:

 

[SlugButter]

Have you ever done an enclosure for a dual isobaric push pull design? I have a few cheap subs sitting in storage and was going to play around with them. They are going to be face to face with one wired out of phase with the other. Always wanted to try using 4 subs in half what the recommended air space is in a push pull design and compare that with 2 subs in a traditional ported setup. I should be able to do half the air space with the isobaric and get the same results as a box twice as large. Going to test it and see how it goes.

 

[Buck]

Have you ever done an enclosure for a dual isobaric push pull design? I have a few cheap subs sitting in storage and was going to play around with them. They are going to be face to face with one wired out of phase with the other. Always wanted to try using 4 subs in half what the recommended air space is in a push pull design and compare that with 2 subs in a traditional ported setup. I should be able to do half the air space with the isobaric and get the same results as a box twice as large. Going to test it and see how it goes.

I haven’t done that, because isobaric was more in a time when subs didn’t have quite as powerful motor tech, from what I understand. Nobody needs isobaric with most subs these days. I would do a subs facing each other isobaric, so it acts somewhat like a supergauss motor design with one coil always in one motor. I think an isobaric bandpass could potentially be a very efficient setup.

 

[SlugButter]

I haven’t done that, because isobaric was more in a time when subs didn’t have quite as powerful motor tech, from what I understand. Nobody needs isobaric with most subs these days. I would do a subs facing each other isobaric, so it acts somewhat like a supergauss motor design with one coil always in one motor. I think an isobaric bandpass could potentially be a very efficient setup.

My plan is to do them face to face with a very small air gap between them. I’m just playing around. This isn’t practical for an every day music system. It requires double the power but half the internal box space as a normal single sub setup. I’m going to use an mdf ring and space the subs 2.25 inches from each other with the cones firing at one another. You mentioned bandpass and that’s exactly what I was thinking of wasting time on after I try it in a simple ported box first. I’m thinking of ordering 4 little cheap 6.5s somewhere online and trying a quad isobaric 6th order. Do you think the same rule would apply on enclosure size? I should be able to cut enclosure size in half and keep the same tuning I believe. Just not sure if it’s going to work the same in a bandpass.

 

[Buck]

My plan is to do them face to face with a very small air gap between them. I’m just playing around. This isn’t practical for an every day music system. It requires double the power but half the internal box space as a normal single sub setup. I’m going to use an mdf ring and space the subs 2.25 inches from each other with the cones firing at one another. You mentioned bandpass and that’s exactly what I was thinking of wasting time on after I try it in a simple ported box first. I’m thinking of ordering 4 little cheap 6.5s somewhere online and trying a quad isobaric 6th order. Do you think the same rule would apply on enclosure size? I should be able to cut enclosure size in half and keep the same tuning I believe. Just not sure if it’s going to work the same in a bandpass.

I haven’t done it, and I would have to deeply look into it further to really know. I do think the port area will probably need to be quite a bit larger doing isobaric. Double the motor, double the power + half the box size = high pressure inside of the loading chamber. Bandpasses help dampen that. You might be more likely to run into chamber losing loading issues and port noise with isobaric. You might try it in sealed first. That might be the best idea to get the airspace ratio the best.

 

[YourNameHere]

Good read...lots of good info about it on the "smart" forum

https://www.diymobileaudio.com/threads/why-is-nobody-using-isobaric-push-pull-anymore.145049/

 

[mr roo]

Some decent info in this on iso.

 

[Buck]

Some decent info in this on iso.

PWK was a huge inspiration to me. He actually took a little bit of time to email me back in 2010, back when I was really trying to understand more about designing and enclosures types. His words helped me understand some larger picture things. He’s definitely a great and legit sound wizard to learn from.

 

[mr roo]

PWK was a huge inspiration to me. He actually took a little bit of time to email me back in 2010, back when I was really trying to understand more about designing and enclosures types. His words helped me understand some larger picture things. He’s definitely a great and legit sound wizard to learn from.

I got a design from him back in the day. Always seemed solid even though I sometimes had not idea what he was telling me. I kicked around a isobaric T line for some 8's. The biggest thing as he points out in this being able to cut down on some of the line area which would help me with size in a trunk.

 

[Buck]

I got a design from him back in the day. Always seemed solid even though I sometimes had not idea what he was telling me. I kicked around a isobaric T line for some 8's. The biggest thing as he points out in this being able to cut down on some of the line area which would help me with size in a trunk.

An isobaric t-line seems counter-intuitive, unless it’s not being used to try to get a low-line resistance. T-lines don’t have much internal loading, which is the point of one, so I’m not sure if I understand why isobaric would be used that way. Not saying it’s wrong.

 

[mr roo]

An isobaric t-line seems counter-intuitive, unless it’s not being used to try to get a low-line resistance. T-lines don’t have much internal loading, which is the point of one, so I’m not sure if I understand why isobaric would be used that way. Not saying it’s wrong.

you should be able to half the cross section needed by a single driver in the same line. The line length would remain the same, but my understanding is that you should be able to cut down some of the port area. Some of the home audio guys also say iso loading eliminates distortion. Now is that something I would ever pick up, probably not in a million years. Cutting the line area would help just in general size of the enclosure.

 

[Buck]

you should be able to half the cross section needed by a single driver in the same line. The line length would remain the same, but my understanding is that you should be able to cut down some of the port area. Some of the home audio guys also say iso loading eliminates distortion. Now is that something I would ever pick up, probably not in a million years. Cutting the line area would help just in general size of the enclosure.

The distortion aspect makes total sense. Combine iso with a tapped line and I bet that’ll sound amazing.