Live Sound & Production

[DBR013]

There were bass bins in the 70's.  I remember those heavy, hefty folded horn jobs back in the 70's.  They were so clunky and cumbersome, it took 4 us us to get them up a spiral staircase along with a Hammond B3 and Leslie.  That was one of the hardest gigs, ever.  But the system sounded real good.  I forgot what we used for tops but the output was tremendous.  We used this system for auditorium sized gigs.  I think eventually the sound company moved to Community speakers and they sounded pretty good, too.

[Dogoth]

Stunningbabe you are thinking in the right direction but not being very clear about it. Let's define some terms first:

Deeper Bass = remains flat response (or within a few db) down to a lower frequency (musical note).

More Bass = efficiency = more spl at some given frequency (let's temporarily use 100hz - an easily achivable frequency for most woofers) for each watt delivered from the amplifier.

Deeper Box = inchs or centimeters from the front (output) side of the enclosure to the opposite side (assuming these sides are both parralel).

Bigger Box = more internal cubic feet/centimeters.

Firstly, I'm NOT a speaker designer but it is my understanding that (as a general rule but not an absolute) a BIGGER box will allow the speaker to move more freely with less power and will increase it's efficience however it's powerhandling capacity is compromised by possible over excusrion of the cone. In a smaller box (given a more powerful amplifier the same SPL can be reached BUT the limiting factor will be heat dissipation of the voice coil). This only addresses the term MORE BASS.

Deeper bass often is a result of a deeper (longer) SIGNAL PATH which MAY or MAY NOT be related to the outside dimentions of the box. Many enclosures mount the driver backwards or even pointed up or down and have an internal maze of signal path (hopefuly tuned and analysed) before the sound exits the "front" of the speaker. In otherwords a 3' deep box may well have a path of 12' from the driver to the front, output side of the box.

In sumnation:

A BIGGER BOX will usualy give you MORE BASS.

A DEEPER (LONGER) SIGNAL PATH) will usualy give you DEEPER BASS.

Again these are generalities. Other factors can bias these statments I.E. speaker design, better or poor box design, expected SPL (Many speakers will reproduce 20hz at a low enough (think unusable) volume).

Yes as in most things in SR it's a series of tradeoffs.

Hope this helps.

[stunningbabe]

JR ...your input DID help. A lot!

[Pro Sound Guy]

There is alot of great DIY'ers out there Twostone.

Heck the Lab Sub from TD is a DIY project.

He basically gave out his design to show that you did not have to spend 4k on a sub to get impressive

results.

There is alot of over priced over rated gear out there!

You can google LAB SUB to see what its all about.

[agedhorse]

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Pro Sound Guy wrote:

There is alot of great DIY'ers out there Twostone.

Heck the Lab Sub from TD is a DIY project.

He basically gave out his design to show that you did not have to spend 4k on a sub to get impressive

results.

There is alot of over priced over rated gear out there!

You can google LAB SUB to see what its all about.

---

The LAB Sub was not a DIY bod in the normal sense. It was essentially designed by somebody who does this for a living and has successful commercial products on the market.

You also do not need to spend $4k on a sub, there are plenty of outstanding subs on the market with very good performance for <$2k.

There are a ton of really poor DIY designs out there, designs that pretend to be something that in practice they are not. Their "designer's" self-promotion as well as their bashing of superior commercial products should be a giant red flag (and certainly is) to those who (really) know how things work. BF is one of them IMO, I have measured and compared side by side with commercial products that he bashed, and in every instance, the commercial product was superior.

[jonthomas]

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JRBLE wrote:

Stunningbabe you are thinking in the right direction but not being very clear about it. Let's define some terms first:

Deeper Bass = remains flat response (or within a few db) down to a lower frequency (musical note).

More Bass = efficiency = more spl at some given frequency (let's temporarily use 100hz - an easily achievable frequency for most woofers) for each watt delivered from the amplifier.

Deeper Box = inchs or centimeters from the front (output) side of the enclosure to the opposite side (assuming these sides are both parallel).

Bigger Box = more internal cubic feet/centimeters.

Firstly, I'm NOT a speaker designer but it is my understanding that (as a general rule but not an absolute) a BIGGER box will allow the speaker to move more freely with less power and will increase it's efficiency however it's powerhandling capacity is compromised by possible over excusrion of the cone. In a smaller box (given a more powerful amplifier the same SPL can be reached BUT the limiting factor will be heat dissipation of the voice coil). This only addresses the term MORE BASS.

Deeper bass often is a result of a deeper (longer) SIGNAL PATH which MAY or MAY NOT be related to the outside dimentions of the box. Many enclosures mount the driver backwards or even pointed up or down and have an internal maze of signal path (hopefuly tuned and analysed) before the sound exits the "front" of the speaker. In otherwords a 3' deep box may well have a path of 12' from the driver to the front, output side of the box.

In sumnation:

A BIGGER BOX will usualy give you MORE BASS.

A DEEPER (LONGER) SIGNAL PATH) will usualy give you DEEPER BASS.

Again these are generalities. Other factors can bias these statments I.E. speaker design, better or poor box design, expected SPL (Many speakers will reproduce 20hz at a low enough (think unusable) volume).

Yes as in most things in SR it's a series of tradeoffs.

Hope this helps.

---

? This is confusing.

Increasing box volume will not make it louder, (at 100hz anyway)

It will improve the bottom end efficiency, and allows for lower tuning (say a port tuned to 35hz rather than 60hz) without a peaky response, (it will go lower and will have a lower f3 point).

Here is a model of what kind of tradeoffs you get with larger boxes and different tunings.

[agedhorse]

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jonthomas wrote:

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JRBLE wrote:

Stunningbabe you are thinking in the right direction but not being very clear about it. Let's define some terms first:

Deeper Bass = remains flat response (or within a few db) down to a lower frequency (musical note).

More Bass = efficiency = more spl at some given frequency (let's temporarily use 100hz - an easily achievable frequency for most woofers) for each watt delivered from the amplifier.

Deeper Box = inchs or centimeters from the front (output) side of the enclosure to the opposite side (assuming these sides are both parallel).

Bigger Box = more internal cubic feet/centimeters.

Firstly, I'm NOT a speaker designer but it is my understanding that (as a general rule but not an absolute) a BIGGER box will allow the speaker to move more freely with less power and will increase it's efficiency however it's powerhandling capacity is compromised by possible over excusrion of the cone. In a smaller box (given a more powerful amplifier the same SPL can be reached BUT the limiting factor will be heat dissipation of the voice coil). This only addresses the term MORE BASS.

Deeper bass often is a result of a deeper (longer) SIGNAL PATH which MAY or MAY NOT be related to the outside dimentions of the box. Many enclosures mount the driver backwards or even pointed up or down and have an internal maze of signal path (hopefuly tuned and analysed) before the sound exits the "front" of the speaker. In otherwords a 3' deep box may well have a path of 12' from the driver to the front, output side of the box.

In sumnation:

A BIGGER BOX will usualy give you MORE BASS.

A DEEPER (LONGER) SIGNAL PATH) will usualy give you DEEPER BASS.

Again these are generalities. Other factors can bias these statments I.E. speaker design, better or poor box design, expected SPL (Many speakers will reproduce 20hz at a low enough (think unusable) volume).

Yes as in most things in SR it's a series of tradeoffs.

Hope this helps.

---

? This is confusing.

Increasing box volume will not make it louder, (at 100hz anyway)

It will improve the bottom end efficiency, and allows for lower tuning (say a port tuned to 35hz rather than 60hz) without a peaky response, (it will go lower and will have a lower f3 point).

An improvement in low end extension increases the area under the curve, which increases average sensitivity over the F3 bandwidth. I think this is what JR was getting at.

[Audiopile]

This might be from way over in left field, but specific to the OP's initial question:  Deeper sub cabinet:

Everything else equal (cubic feet of the enclosure, drivers, porting etc...), I'll suggest that a deeper, rather than taller or wider cabinet, would likely couple better with the ground... thus possibly alterting performance in a desirable manner.

[Pro Sound Guy]

I am certainly not endorsing BF's designs here Aged.

I am however, trying to get the OP to look into loudspeaker design to hopefully get people to see

why some things are the way they are with loudspeakers/boxes.

Also, TD designed the lab sub to stomp some of the high dollar designs out there that cost a huge

amount of ching, and in doing so he gives DIY people a chance to enjoy one of his designs.

You are correct in saying there is alot of DIY junk out there but there is also alot of DIY designs available

to the public that really perform well.    How many cookie cutter square boxes are out there that companies

plop drivers in and port?

I guess I dont look at DIY as someone who designs a cab, and builds it, but

people who use plans and build the cabs, and also make their own passive xovers, and hang out on

forums and talk about designs/horns/drivers/crossovers values/compression drivers/loudspeakers, etc.

There is plenty of commercial plans available for the public for use as well.  

I have looked into BF's designs and pro's and cons and I am convinced that I would have no interest in

building pro sound cabinets with 1/2 inch plywood.

Also, in shootouts the boxes tend to not perform as advertised.

Bracing or not 1/2 inch plywood for pro use is well kinda DJ like.

Im not disagreeing with your comments here but simply adding my thoughts. 

Your experience and knowledge is very well appreciated Aged.

[jonthomas]

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Audiopile wrote:

This might be from way over in left field, but specific to the OP's initial question:  Deeper sub cabinet:

Everything else equal (cubic feet of the enclosure, drivers, porting etc...), I'll suggest that a deeper, rather than taller or wider cabinet, would likely couple better with the ground... thus possibly altering performance in a desirable manner.

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With the larger the baffle (front of the speaker), you will get a greater the reinforcement of low frequencies and less diffraction loss. It is more of a issue with tops and the mid bass frequencies (above 200hz) than with subwoofers. Speakers that are not coupled to the floor can drop around 6db at those frequencies due to the unidirectional nature of bass.

I doubt any measured baffle reinforcement or loss will happen with the wavelengths below 100hz with a box you could transport effectively. (you could not make the baffle large enough to make a difference.) 

[agedhorse]

IMO, it is possible (with the proper engineering) to use 1/2" plywood but that requires understanding the structural stiffness criteria and pay attention to more detail than many folks are willing to do... or even perhaps the weight savings may not be as great compared with the additional cost of the stiffening efforts.

I have used a variety of materials, for subs I tend to stick with ~3/4" but I have also used 1.25" fir/pine ply composite as well as 1/2" with stiffening and bracing so there's really no hard and fast rule. 3/4" works well because the material holds the hardware well, is a good combination of stiffness (using the right materials) without the added costs when working with 1/2", especially as the cabinet gets larger.

Regarding BF's cabinets, regardless of the thickness of the material, the performance of the ones that I have measured were abominal at best. Certainly could not "stomp" the claimed commercial cabinets and in fact got pretty well stomped in the measurements that I took for a client. When he saw the results as I was measuring, he immediately made up his mind to sell them and quick. His new mid level JBL cabinets are leaps and bounds better and most importantly, the client has no doubts.

[Mogwix]

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Bobby1Note wrote:

A fellow Formula One fan????

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I actually don't watch F1... I love watching ELMS and ALMS,  Super GT and V8 supercars.

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agedhorse wrote:
When he saw the results as I was measuring, he immediately made up his mind to sell them and quick.

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I was going to make a comment that hype has no bearing when a product is tested and measured... but those tests and measures can very well be biased to reflect one way or another.

[Dogoth]

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agedhorse wrote:

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jonthomas wrote:

? This is confusing.

Increasing box volume will not make it louder, (at 100hz anyway)

It will improve the bottom end efficiency, and allows for lower tuning (say a port tuned to 35hz rather than 60hz) without a peaky response, (it will go lower and will have a lower f3 point).

An improvement in low end extension increases the area under the curve, which increases average sensitivity over the F3 bandwidth. I think this is what JR was getting at.

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Ya. I thought it was a little confusing as well. Sorry.

When talking about enclosure size & efficiency, I was mostly thinking about the amount of air behind the driver acting as a dampener (if it's a sealed box or if the ports remain the same dimensions). As I stated I'm not a speaker designer and am only working off of past observations.

Thanks for setting the record straight.

[stunningbabe]

as usual...I am lost here after reading all these technical discussion.

ANyone care to simplify things for me please?

[dboomer · Accepted solution]

You are expecting that there is a single answer to your question. There is not. As I wrote before, there are three interrelated factors.

So a bigger box CAN result in deeper bass... But " will" depends.

[Craigv]

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twostone wrote:

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Pro Sound Guy wrote:

The size of the box DOES matter in a vented design and must be bigger for sub 40hz.

You have sealed boxes.

You have vented boxes.

You have horn loaded boxes.

You have Bass horn boxes.

All four are different animals.

Stunningbabe you might want to simply research subwoofer DIY and designs.

Go to a forum like Bill Fitzmaruice and read on.

http://billfitzmaurice.info/forum/

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I always wondered if those DIYer's could hang with the factory made cabs.

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Weren't you here back when I built a pair of his Tuba 24's? It was a epic thread that took on a life of its own. I'll just say that BF never let me join his website's forum to address what was written about me....

[RoadRanger]

Just for those who want to DYI these are the real deal:

http://speakerplans.com

No BF BS .

OTOH the resale value of DYI cabs sucks - I bought a pair of the 186's (built well in a cabinet shop) for the cost of the drivers. They calculate out to 137db @ 1 meter peak as a clustered pair, it's unpleasant to get within 15 feet of them outdoors  .