Recently I turned a dying pair of Sansui's into open baffle speakers. After I finished wiring the drivers, I realized that they all had closed backs. This got me to thinking, Do closed back drivers defeat the purpose of an open baffle set up?
Forgive my ignorance, I see talk about closed speakers boxes in that link, but I don't see/ understand anything that directly mentions closed back drivers in an open baffle set up.
Well, not true because the woofer was bi-directional. The rest of the drivers, being closed -back, represent an oxymoron if used for dipolar configuration.
The terminology is a little confusing.
1. You can have a closed box speaker with a large overhanging baffle. This is good because the needs of the baffle and the needs of the closed box are not always the same in a design. This is not an open baffle.
2. The traditional meaning of an open baffle speaker is one that doesn't have an enclosed back.
3. A modern variation is a speaker that resembles a dipole type but doesn't necessarily have the specific baffle arrangement to meet the criteria of a dipole.
1. You can have a closed box speaker with a large overhanging baffle. This is good because the needs of the baffle and the needs of the closed box are not always the same in a design. This is not an open baffle.
2. The traditional meaning of an open baffle speaker is one that doesn't have an enclosed back.
3. A modern variation is a speaker that resembles a dipole type but doesn't necessarily have the specific baffle arrangement to meet the criteria of a dipole.
Yes indeed. This can be called a 'zero-deepness' box. Well, not a box but something that encapsulates the drivers. Difference from a box is that it's a boundary in the real sense. A parallelogram of a certain size -a box- offers 4 + surfaces plus the baffle itself for secodary ( third -eleventh...) reflections
so it can be considered a real 3D object.
The diffraction products of the different geometries ( flat boundary Vs 3D size comparable or similar object ) and the different ( mono or dipole ) radiations contribute to the phenomenon.
Notwhistanding that, there are some people that analyze the single hole/cavity on the basket for the study of the rear radiation. yes everything sounds!
ABout OP's speakers, maybe a grinder would change Qts...!
so it can be considered a real 3D object.
The diffraction products of the different geometries ( flat boundary Vs 3D size comparable or similar object ) and the different ( mono or dipole ) radiations contribute to the phenomenon.
Notwhistanding that, there are some people that analyze the single hole/cavity on the basket for the study of the rear radiation. yes everything sounds!
ABout OP's speakers, maybe a grinder would change Qts...!
Do you mean the midrange drivers ??
closed back speakers can imply midrange speakers with a closed basket which typically run in 4" to 10" size and have high Qtc and relatively high resonance due to their very small air volume behind the cone. Those could be employed on an open baffle along with open back basket woofers. You are free to mix ;^)
https://eminence.com/cdn/shop/produ...2d-071201cfd678_1024x1024@2x.jpg?v=1590673566
closed back speakers can imply midrange speakers with a closed basket which typically run in 4" to 10" size and have high Qtc and relatively high resonance due to their very small air volume behind the cone. Those could be employed on an open baffle along with open back basket woofers. You are free to mix ;^)
https://eminence.com/cdn/shop/produ...2d-071201cfd678_1024x1024@2x.jpg?v=1590673566
Yes Freddi, I should have specified. I do mean the midrange drivers and thank you for the response.
It will be a baffle but it will not be open. Pico’s zero thickness loudspeaker is a good term.
dave
dave
Let's start again , your original heading is confusing/wrong.
Really?
* How many speakers are we talking here?
* Size of each?
" Are all closed back or only some of them?
I'm new to diyAudio and building speakers. I'm sorry if I'm confusing you. Are the closed backs on the drivers better or worse for open baffle speakers?
6 speakers :
one horn super tweeter ( 1 3/8inch ),
two horn tweeters ( 2 inch )
two mids ( one 5 inch and one 6 inch )
one woofer (12 inch )
All are closed back except for the woofer.
An open baffle ideally radiates the same from both sides.
A closed back driver is a driver with a built-in sealed box.
dave
I have older 'portable' hifi equipment which has open back speakers for space saving purposes. The rear radiation is not a real consideration, and it just falls into the overall compromise. More baffle equals more bass.
The thing is that they can still sound quite good. It's interesting to speculate whether people made the same connection between open and closed, back in the day.
The thing is that they can still sound quite good. It's interesting to speculate whether people made the same connection between open and closed, back in the day.
Well, usually I do the opposite: I put the woofer in box and leave the mid outside, with the back covered with strips of (real) felt. We are talking about regular speakers with an open basket. The tweeter is usually a closed back kind of speaker. All this to say that I aim for monopole/ only forward emission.
Which can only happen when the source is one, not corrupted. Indeed a box can radiate so it produces extra sounds.
p.s. grinder
Which can only happen when the source is one, not corrupted. Indeed a box can radiate so it produces extra sounds.
p.s. grinder
Thanks.
No big deal on the tweeters; woofer will definitely work like on an open baffle design; not so sure on midrange.
From my point of view, others may diverge, not that worried about bipolar "sound emission" but instead about boxiness (literally) caused by the closed back.
Which will cause a strong resonant peak very near the working Audio band for that midrange speaker.
Nominally outside its rated band BUT crossovers are never "brick wall", all have a more or less gradual slope, so that resonant peak WILL be excited by audio and noticeable.
That midrange unit will sound "closed box" ... because it is so 🤷