bass sound

[jefffluker]

Fellow sound-o-philes,

I come to the collective for stories and opinions.

With regard to woofer/subwoofer cabinets--how do you know when you've really "got it?"

I have experimented extensively with various driver brands, enclosure types, box volume, tuning freq, damping--seeking that "break up kidney stones" bass.

I mostly DJ, so I've tried to balance "thump" and "boom, " succeeding (I think) a few times. I built an unholy twin 15 2-way with the discontinued Dayton 15s. Huge and heavy, but LORD does it hit! I also attempted a twin 18 with the discontinued Daytons. Not so good...

Tried the "sweep & measure" tuning method, checking for the telltale resistances. Could anyone suggest a simplified means of tuning this way?

Are there advantages to slot porting over cylinder?

Pros/cons of the neodymium magnet drivers?

Has anyone built a sub with a 21" or 24" woofer?

What's your "go-to" driver or brand?

Do the the PRV drivers work well?

Why are the JBL woofers so costly? Are they really that much better?

Has anyone run a LARGE bank of subwoofers (20-30?)

Please relate any subwoofer stories, good or bad.

Thanks for reading.

Jeff
[email protected]

[mdocod]

Re: bass sound

Fellow sound-o-philes,

I come to the collective for stories and opinions.
With regard to woofer/subwoofer cabinets--how do you know when you've really "got it?"

You really won't know for sure whether you "got it" nailed down until after something is built, broken in, and measured in real world venues. Spend enough time studying acoustic principals and learning simulation software and you'll be able to build something that's "got it" pretty good nearly every attempt.

I have experimented extensively with various driver brands, enclosure types, box volume, tuning freq, damping--seeking that "break up kidney stones" bass.

Built any bass horns? A big bass horn to cover ~30-80hz, and then a "kick" horn for ~80-200+hz is something I am seeing more of these days. (Sometimes the "kick" bin reaches up higher, depends on design). The specialized horn for that upper bass range can really provide the sort of intensity needed to bust up those stones, while a dedicated passband low frequency horn can provide an unexpected level of organ rearrangement.

I mostly DJ, so I've tried to balance "thump" and "boom, " succeeding (I think) a few times. I built an unholy twin 15 2-way with the discontinued Dayton 15s. Huge and heavy, but LORD does it hit! I also attempted a twin 18 with the discontinued Daytons. Not so good...

You're using your tops for bass reinforcement?

Tried the "sweep & measure" tuning method, checking for the telltale resistances. Could anyone suggest a simplified means of tuning this way?

Simulation is extremely accurate these days. Just make sure to build what you simulate, or simulate what you have built to make adjustments. I think for bass bin simulation nothing beats hornresp.

Are there advantages to slot porting over cylinder?

The advantage is practicality. It's sometimes easier to hit the required port cross section with a slot, and the resulting baffle-in-box to make the slot port adds desirable rigidity to the box. Hint: Port cross section does not have to be as large if the ends are flared. Hint again: if you're already folding up a slot port in a box, simulate a transmission line instead and see if you can get more gain inside the same box volume.

Pros/cons of the neodymium magnet drivers?

Weight vs cost. Lighter pro-sound gear is easier on the back and harder on the wallet. In most bass bin applications, the drivers don't need particularly massive magnets compared to the weight of the entire box anyway (it's probably a heavy bin that's going to be moved with a dolly so ferrite is fine). The best place for neo is in the tops, where extraordinarily high EBP midbass drivers are typically used. The motor strength required typically comes with a HUGE HEAVY ferrites. (yes it's not uncommon for for the midbass driver in the top to have a larger magnet than the "bigger" sub driver). Switching to neo here is the most useful application, since these boxes are typically hoisted up on speaker stands.

Has anyone built a sub with a 21" or 24" woofer?

Bigger driver does not necessarily mean more acoustic displacement. Pro-sound subs can be built from 8" car subs in the right box.

What's your "go-to" driver or brand?

Picking a driver is more complex than going to a brand for a solution. Plenty of great drivers to choose from from lots of brands out there. It's about finding *the* driver that matches the bandwidth, output, and directivity needs of a system.

Why are the JBL woofers so costly?

I have heard a theory around here that perhaps they do not want their drivers to be seen/heard in poor DIY implementations that would hurt their brand image. Which, FYI, is very good overall. JBL has been a serious leader in sound reinforcement technology, and a pioneer of many of the technologies used in PA today.

Are they really that much better?

I don't have reason to believe that they are better by a margin that is inline with their higher driver prices. A proper implementation of any decent quality pro-sound driver can sound fantastic.

Thanks for reading.

Jeff

If you would like further insight into any of what I am sharing above don't hesitate to ask.

Regards,
Eric

[jefffluker]

Re: bass sound

Hi Eric,

Thank you for your reply.

Over the years, I've tried different designs with so much different gear with mixed results. I'm a bit weary.

On the drawing board is a twin 15 2-way using Peavey Low Riders and a PRV 2" compression driver. Something tough and simple for a Mardi Gras float rental. We'll see..

Jeff
[email protected]

[sn95]

Re: bass sound

I think that the first thing is application ,( how much SPL ,low F3 ,number of people,room size ,indoors ,out doors ) than look at designs or styles of box that will work .all have pros and cons .

The PRV 21 looks to be a good fit for a super scooper ,but scoops have some cons

As for your two 15s * 2 horn (I'm no expert but sounds like a compromise )

[jont]

Re: bass sound

You really won't know for sure whether you "got it" nailed down until after something is built, broken in, and measured in real world venues. Spend enough time studying acoustic principals and learning simulation software and you'll be able to build something that's "got it" pretty good nearly every attempt.



Built any bass horns? A big bass horn to cover ~30-80hz, and then a "kick" horn for ~80-200+hz is something I am seeing more of these days. (Sometimes the "kick" bin reaches up higher, depends on design). The specialized horn for that upper bass range can really provide the sort of intensity needed to bust up those stones, while a dedicated passband low frequency horn can provide an unexpected level of organ rearrangement.



You're using your tops for bass reinforcement?






Simulation is extremely accurate these days. Just make sure to build what you simulate, or simulate what you have built to make adjustments. I think for bass bin simulation nothing beats hornresp.


The advantage is practicality. It's sometimes easier to hit the required port cross section with a slot, and the resulting baffle-in-box to make the slot port adds desirable rigidity to the box. Hint: Port cross section does not have to be as large if the ends are flared. Hint again: if you're already folding up a slot port in a box, simulate a transmission line instead and see if you can get more gain inside the same box volume.


Weight vs cost. Lighter pro-sound gear is easier on the back and harder on the wallet. In most bass bin applications, the drivers don't need particularly massive magnets compared to the weight of the entire box anyway (it's probably a heavy bin that's going to be moved with a dolly so ferrite is fine). The best place for neo is in the tops, where extraordinarily high EBP midbass drivers are typically used. The motor strength required typically comes with a HUGE HEAVY ferrites. (yes it's not uncommon for for the midbass driver in the top to have a larger magnet than the "bigger" sub driver). Switching to neo here is the most useful application, since these boxes are typically hoisted up on speaker stands.


Bigger driver does not necessarily mean more acoustic displacement. Pro-sound subs can be built from 8" car subs in the right box.


Picking a driver is more complex than going to a brand for a solution. Plenty of great drivers to choose from from lots of brands out there. It's about finding *the* driver that matches the bandwidth, output, and directivity needs of a system.


I have heard a theory around here that perhaps they do not want their drivers to be seen/heard in poor DIY implementations that would hurt their brand image. Which, FYI, is very good overall. JBL has been a serious leader in sound reinforcement technology, and a pioneer of many of the technologies used in PA today.


I don't have reason to believe that they are better by a margin that is inline with their higher driver prices. A proper implementation of any decent quality pro-sound driver can sound fantastic.



If you would like further insight into any of what I am sharing above don't hesitate to ask.

Regards,
Eric

Holly vague post batman!

Size?
Cost?
Coverage? (what you are trying to accomplish?)

DIY horns excel in situations where power and $ are the determining factors.
Commercial products are necessary for riders/professional appearance.
$$$ is necessary when you are trying cram the maximum SPL into the smallest space whether you are using off the shelf products or not.

The state of the art drivers are neo and you cannot buy them http://www.bcspeakers.com/products/l...eo/21-0/21ipal

[Paul O]

Re: bass sound

On the drawing board is a twin 15 2-way using Peavey Low Riders and a PRV 2" compression driver.

Make the boxes big and cross it actively no higher than 800hz and it make some noise for sure.