QUICK Question on baffles

[rodl2005]

Hi all, while reading the BP mag's article on the AMPEG HERITAGE B-15 I noticed Jess Oliver stating how the B-15R had a different baffle design -infinate was it?

Now I know a little about cabs, but ALL you guys- & there ARE many- with far more knowledge than I on these matters,
COULD you PLEASE explain to me the different designs.
1. The BAFFLE baffles me........ It's the part of the cab WITH the speaker attached- yes???
Now I KNOW what a SEALED cab is.... & these have ONE baffle in the case of say a cab such as the SVT810 or my NV215- am I right SO far?? I wouldn't be surprised either way

2. Mr. Oliver stated how the B-15 had a DOUBLE BAFFLE.... please explain!!!!

3. Are ported cabs usually a regular ... awwww heck I'll leave it there.

I've seen the Orange ISOBARIC cabs- one sealed driver & one ported driver behind it... BAFFLING!!!

PLEASE help me understand this stuff.

Thanks
Rod

[Venom of God]

This is only the second time I've ever seen another Tasmanian on here!

[JimmyM]

Originally Posted by rodl2005

Hi all, while reading the BP mag's article on the AMPEG HERITAGE B-15 I noticed Jess Oliver stating how the B-15R had a different baffle design -infinate was it?

Now I know a little about cabs, but ALL you guys- & there ARE many- with far more knowledge than I on these matters,
COULD you PLEASE explain to me the different designs.
1. The BAFFLE baffles me........ It's the part of the cab WITH the speaker attached- yes???
Now I KNOW what a SEALED cab is.... & these have ONE baffle in the case of say a cab such as the SVT810 or my NV215- am I right SO far?? I wouldn't be surprised either way

2. Mr. Oliver stated how the B-15 had a DOUBLE BAFFLE.... please explain!!!!

3. Are ported cabs usually a regular ... awwww heck I'll leave it there.

I've seen the Orange ISOBARIC cabs- one sealed driver & one ported driver behind it... BAFFLING!!!

PLEASE help me understand this stuff.

Thanks
Rod

1. yes, it's the front of the cab where the speaker is mounted. the vast majority of cabs have one baffle, sealed or ported. and "infinite baffle" is another way to say "sealed."

2. the speaker is mounted on an inner baffle that has 8 slots all around the baffle to port it. in front of that is a second baffle that takes the sound from the ports and directs it to in front of the speaker. not sure how necessary that is to have the second baffle, and i'm sure there are more efficient ways of porting that cab that would work just as well, but it darn sure sounds great.

3. i'll leave it at that, too.

[billfitzmaurice]

The double baffle is a ported cab, it's just a different way of doing it. Not better or worse, just different.

[rodl2005]

BAH!!! Still Baffling! Thanx guys.

DOUBLE BAFFLE - is right OMG!

So thanx for the explanation Jimmy, & I understand it's a PORTED type thing- Gee I s'pose here a diagram would REALLY help :-/

Jimmy, you say :-

2. "the speaker is mounted on an inner baffle that has 8 slots all around the baffle to port it. in front of that is a second baffle that takes the sound from the ports and directs it to in front of the speaker. not sure how necessary that is to have the second baffle, and i'm sure there are more efficient ways of porting that cab that would work just as well, but it darn sure sounds great."


It DOES sound great!!
- So the baffle WITH the Driver mounted to it has 8 slots or ports & there's another baffle in FRONT of this???

You can still see the speaker- so I take it that this FRONT baffle is cut with a 15" speaker hole? Yes?
Ahhh I'm all confused. Sorry!

[Vintage-Blue]

I don't know if these photos will help or not. The inner (speaker) baffle is fixed and cannot be removed. This is the baffle that has the ports cut in it. The outer (grille) baffle is removable and attaches to the speaker baffle. There are four spacers that create a 3/8" space between the two baffles:







Also, here is a photo that shows something Jess Oliver was working with a few years ago. He had removed the 3/8" spacers and replaced them with plastic tubing so that he could experiment with different spacing between the baffles.

[Trauma]

Infinite baffle usually refers to a free-air speaker ie mounted but unenclosed in the rear like most automobile speakers

[HolmeBass]

Originally Posted by Trauma

Infinite baffle usually refers to a free-air speaker ie mounted but unenclosed in the rear like most automobile speakers

Or open-backed guitar amps/cabs, like a Fender Twin.

[rodl2005]

THANX Vintage Blue- THAT explains a HEAP!! GOT it now!!!!

Yeeehaaa!!!!

[JimmyM]

sorry guys, could have sworn i've heard infinite baffle used referring to sealed cabs, but i looked it up and it sounds like you guys were right.

[johnk_10]

AfAIK, an infinite baffle threoretically is completely isolating the sound radiated by the front of the cone to sound coming from the rear of it. the purpose being to keep F/R frequencies from cancelling each other out. but in practical terms, i've alsways thought of it the same way as Jimmy, i.e., a sealed cab. at least that what they called them in the old days.

to me, an open back cab is not really an infinite baffle either.

[billfitzmaurice]

Originally Posted by Trauma

Infinite baffle usually refers to a free-air speaker ie mounted but unenclosed in the rear like most automobile speakers

Infinite baffle is where the front and rear radiations from the driver never meet. That can be a tiny sealed cab, or a driver placed in a wall or ceiling, with the opposite room or attic serving as the 'cabinet'. The term IB is usually applied to the latter as far as hi-fi is concerned, but it equally applies to an SVT as well. Never to open back, and technically never to free-air, unless the driver is mounted in the exterior wall of the house. Even then it's not a true free-air situation, as the house becomes the sealed cabinet. Or vented, if you leave a window open.

[JimmyM]

ah, so i WAS right! sort of

[Trauma]

Everybody's right, uh, kind of... )

[Alex1984]

Originally Posted by billfitzmaurice

Infinite baffle is where the front and rear radiations from the driver never meet. That can be a tiny sealed cab, or a driver placed in a wall or ceiling, with the opposite room or attic serving as the 'cabinet'. The term IB is usually applied to the latter as far as hi-fi is concerned, but it equally applies to an SVT as well. Never to open back, and technically never to free-air, unless the driver is mounted in the exterior wall of the house. Even then it's not a true free-air situation, as the house becomes the sealed cabinet. Or vented, if you leave a window open.

WOW, can we design a house that acts as a cab? Sounds like fun! (Although, I don't think the girlfriend will approve...)

[MuzikMan]

Originally Posted by Alex1984

WOW, can we design a house that acts as a cab? Sounds like fun! (Although, I don't think the girlfriend will approve...)

I'm pretty sure some people use there attic as a cab!

[Mr. Foxen]

Originally Posted by rodl2005

I've seen the Orange ISOBARIC cabs- one sealed driver & one ported driver behind it... BAFFLING!!!

This bit kind of got skipped over. Isn't really a sealed driver, they work in unison, so the pressure between the two stays the same (hence isobaric), effectively it is a ported box and the two drivers act as one double weight double powered driver. There is a little bit of mess from the time the sound takes to get from one driver to the other, but mostly, it is like that.

[NoGraveConcern]

Originally Posted by Alex1984

WOW, can we design a house that acts as a cab? Sounds like fun! (Although, I don't think the girlfriend will approve...)

Any enclosed space acts as a cab, or part of the system. The size of the room and other factors effect cabin gain and resonant frequencies.

[rodl2005]

Originally Posted by Mr. Foxen

This bit kind of got skipped over. Isn't really a sealed driver, they work in unison, so the pressure between the two stays the same (hence isobaric), effectively it is a ported box and the two drivers act as one double weight double powered driver. There is a little bit of mess from the time the sound takes to get from one driver to the other, but mostly, it is like that.

Thanx for that Mr. Foxen,

Has anyone USING these Orange ISOBARIC cabs got any opinions??
e.g. -
Does the 2x10 sized 410 actually put out as much SOUND as a regular 410?

[billfitzmaurice]

Originally Posted by rodl2005

Thanx for that Mr. Foxen,

Has anyone USING these Orange ISOBARIC cabs got any opinions??
e.g. -
Does the 2x10 sized 410 actually put out as much SOUND as a regular 410?

No. It puts out as much sound as two tens in a cab twice its size.