I have two pairs of speakers that I've always loved, and loved so much that I've kept them for years and years. Both are un-ported, sealed boxes. With all the talk of open baffle and the incredibly complex porting arrangements I see being implemented, I find it surprising that I have always preferred a sealed box to the (admittedly fairly low end) hifi speakers with ports.
These speakers I own are Celestion Ditton 44 (with rebuilt X-overs and replacement Seas 19mm tweeters) and Mission 761 (original version).
Is there any positive reason that the design of a sealed box might be a sound I like??? It does seem to have something to do with the often artificial bass I hear from ported boxes, though I guess high end stuff doesn't suffer that!
These speakers I own are Celestion Ditton 44 (with rebuilt X-overs and replacement Seas 19mm tweeters) and Mission 761 (original version).
Is there any positive reason that the design of a sealed box might be a sound I like??? It does seem to have something to do with the often artificial bass I hear from ported boxes, though I guess high end stuff doesn't suffer that!
Hi Lucas,
Hard to tell. Depends on what exactly you are comparing. I've read a lot of myths about sealed always sounding better, etc. and I find the reasons given are either just technically unsupportable or misguided. Also, with sealed and with ported speakers, there are a lot of different alignments which can be achieved. It's certainly possible you were listening to some boomy ported speakers. I know for sure I could make crappy sounding ported OR sealed speakers. 😀 😀 😀
I'm listening to large stand mounted ported speakers as I type this, and I wouldn't give up the 20-30Hz extra I get in the bass for anything, except a sub. 🙂
Be a little more specific, and if possible, can you put it into the context of some popular speakers we may have heard?
Best,
Erik
Hard to tell. Depends on what exactly you are comparing. I've read a lot of myths about sealed always sounding better, etc. and I find the reasons given are either just technically unsupportable or misguided. Also, with sealed and with ported speakers, there are a lot of different alignments which can be achieved. It's certainly possible you were listening to some boomy ported speakers. I know for sure I could make crappy sounding ported OR sealed speakers. 😀 😀 😀
I'm listening to large stand mounted ported speakers as I type this, and I wouldn't give up the 20-30Hz extra I get in the bass for anything, except a sub. 🙂
Be a little more specific, and if possible, can you put it into the context of some popular speakers we may have heard?
Best,
Erik
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As an example, I made the LM-1 speaker kit. If I put it on a bookshelf or very close to the rear wall I seal the ports with towels or clean socks. When I have more space I leave them open.
I don't hear a difference in quality, but adjusting the port allows me to hear a more consistent tonal balance regardless of speaker placement.
I don't hear a difference in quality, but adjusting the port allows me to hear a more consistent tonal balance regardless of speaker placement.
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Hi,
Lining the ports with foam is generally better than sealing them.
For the LM-1 you want a piece of open cell foam 4.5" x 4.0". The
thickness can vary, just fold into a tube and insert into the port.
For the LM-1 you probably want 1/4" thickness to 3/8" thickness.
rgds, sreten.
Lining the ports with foam is generally better than sealing them.
For the LM-1 you want a piece of open cell foam 4.5" x 4.0". The
thickness can vary, just fold into a tube and insert into the port.
For the LM-1 you probably want 1/4" thickness to 3/8" thickness.
rgds, sreten.
Thanks for the responses.
Erik, 20 - 30 Hz you get extra from having a port? Surely only on a small bookshelf speaker. Even then, that's hard to believe.
My Celestion Ditton 44 speakers are 3 way with a 12" woofer, and go down to a quite respectable 25Hz, where of course they are slightly rolled off, but it's still very present and controlled. 40Hz is presented at normal volume level, and is very clean.
Erik, 20 - 30 Hz you get extra from having a port? Surely only on a small bookshelf speaker. Even then, that's hard to believe.
My Celestion Ditton 44 speakers are 3 way with a 12" woofer, and go down to a quite respectable 25Hz, where of course they are slightly rolled off, but it's still very present and controlled. 40Hz is presented at normal volume level, and is very clean.
Lucas,
I don't think that's atypical for a bookshelf. Look at any of the woofers for sale at Madisound or Parts Express and they'll list rough -3 dB points for each alignment.
Best,
Erik
Best,
Erik
I don't think that's atypical for a bookshelf. Look at any of the woofers for sale at Madisound or Parts Express and they'll list rough -3 dB points for each alignment.
Best,
Erik
Best,
Erik
I find different speaker topologies sound different.
I find my folded horn speakers very efficient but lack a bit of bass.
I have a half folded horn that isn't as efficient but the bass is much stronger.
I have sealed boxes that lack a bit of bass.
I find my folded horn speakers very efficient but lack a bit of bass.
I have a half folded horn that isn't as efficient but the bass is much stronger.
I have sealed boxes that lack a bit of bass.
OH, I see the problem. 🙂
The key word was "extra" as in, without the port, the -3dB point goes UP about 20 to 30 Hz, not "up to".
For instance for the LM-1 the -3dB points is 60Hz ported but about 80Hz, ish, sealed.
Sorry for the confusion.
The key word was "extra" as in, without the port, the -3dB point goes UP about 20 to 30 Hz, not "up to".
For instance for the LM-1 the -3dB points is 60Hz ported but about 80Hz, ish, sealed.
Sorry for the confusion.
We can predict quite accurately how a woofer will behave with box modeling programs nowadays. The trouble is, it doesn't tell us how it sounds. The only way is to test it out.
Take my 15" Kicker for example. Nice low bass. However, detail in the mid-bass is lacking. And this is in a Sealed box of 100L. So, if I want to use this Kicker, I'll cross at 70Hz and let my mid-woofer take care of the mid-bass, that is provided the mid-woofer has a nice mid-bass.
Large woofers in a sealed boxes that used to be built at earlier times
were simply decently designed products and that is the reason you like it. The
same would apply to a vented cabinet or any other cabinet type. Modern cheap
loudspeakers have to high of a Qts in a vented cabinet and put in a small room
is destined to sound boomy.
Yes, large paper cones in cast baskets are also something I've always liked a lot, and tend to be from older designs, like Tannoy Golds, Celestion 44s etc.
Perhaps the answer is just that they are well designed with quality drivers, and I like that 3 way sound with large paper cones.
Could placement/intended placement be part of this?
In the olden days most speakers were designed to be placed close to a wall and low Qts drivers like vintage Tannoys help here quite naturally.
Tuned (ok I'm talking ported here rather than sealed) for maximum extension they are not flat but show a bass shelf (see curve c in this link Tannoy Monitor Gold Crossover: Frequency Response) which doesn't look all that good.
However this is the predicted free space response and once you stick those on a wall in a room boundary reinforcement will make up most of what is 'missing'.
These days most speakers are designed to be free standing and show a flat FR that way but once you put them into a small to medium room and/or near walls they sound horribly bloated in the low bass.
Sealed boxes with their shallower roll off behave a bit like that too in that via the boundary reinforcement they have useful unbloated bass to quite a bit below their official -3dB point.
In the olden days most speakers were designed to be placed close to a wall and low Qts drivers like vintage Tannoys help here quite naturally.
Tuned (ok I'm talking ported here rather than sealed) for maximum extension they are not flat but show a bass shelf (see curve c in this link Tannoy Monitor Gold Crossover: Frequency Response) which doesn't look all that good.
However this is the predicted free space response and once you stick those on a wall in a room boundary reinforcement will make up most of what is 'missing'.
These days most speakers are designed to be free standing and show a flat FR that way but once you put them into a small to medium room and/or near walls they sound horribly bloated in the low bass.
Sealed boxes with their shallower roll off behave a bit like that too in that via the boundary reinforcement they have useful unbloated bass to quite a bit below their official -3dB point.
Yes, speaking of sound power, a f-3dB of 80 Hz of a sealed box easily turns into a f-3dB of 40 Hz thanks to room gain. Speaking of sound pressure, level is off in most listening places, no matter if sealed or ported.
Also in favor of sealed enclosures: It can be stuffed, so standing air waves inside the box are no issue. Furthermore, there is no port, which would resonate on its own at higher frequencies.
Also in favor of sealed enclosures: It can be stuffed, so standing air waves inside the box are no issue. Furthermore, there is no port, which would resonate on its own at higher frequencies.
What about F10? F6? Toole has shown that to human hearing F3 is a more-or-less meaningless spec.
dave
Living in a typical terraced english 2 up 2 down house i have found sealed boxes sound much better in my situation and i 'll take clarity speed and precision over boomy muddy bass any day.
Plus my neighbours appreciate my preference 🙂
Plus my neighbours appreciate my preference 🙂
Personally I wouldn't be looking at the speaker design to examine why you love them .
I would be looking at yourself and your music taste and the kind of sound you like, coupled with how much your tastes have changed/not changed , your personality traits too even - some people do stick with something for years and years, be that car brands, shoes, place you live etc and always long for that familiarity when straying away so return quite readily.
Whilst having liked the sound of similar speakers like Celestion 332, 15XRs etc I had for a while, when I changed to radically different speakers my ears tuned to a different type of sound and I moved to loving what they brought to the party instead. My music tastes have changed too over the years. (My first, definate move away from those Celestions were some B&W Matrix 805s - the comparative lack of box colouration was startling when going back to the others I had; Celestion 332s, AVI Biggertrons, thingy HB1s. On a quick A/B you immediately heard the wooden thunk of the cabinets putting it's signature over everything! )
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Jeff Bagby has done this nice simulator. Loudspeaker Design Software
A reflex tuned around 40Hz (typcal) fall so rapidly below tuning that it won't benefit so muxh from front wall. A sealed box speaker also gives room pressurization below first room mode, if Sd is big enough. A cardioid bass speaker is almost immune to front wall reinforcement, but reacts with floor naturally.
A link to this subject http://www.musicanddesign.com/Boundary_reflections.html
A reflex tuned around 40Hz (typcal) fall so rapidly below tuning that it won't benefit so muxh from front wall. A sealed box speaker also gives room pressurization below first room mode, if Sd is big enough. A cardioid bass speaker is almost immune to front wall reinforcement, but reacts with floor naturally.
A link to this subject http://www.musicanddesign.com/Boundary_reflections.html
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For sealed, F3 will largely correlate with shifts in F6 or F10 unless the alignment is infinite baffle or high Q, so it's a viable comparator. A little more complex if you're comparing other alignment types.
That is true, sealed will be a 2nd order roll-off, so as long as they are the same Q, F3 will mirror F6/F10, but comparisons were being made between sealed & vented where F3 can be a very unreliable quantitiative measure of bass extension.
dave
dave
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