Speaker ported vs plugged?

[Oski1928]

Hi, got some new speakers in and they came with optional port plugs. I did a very rudimentary experiment to see how they perform with and without the plugs. I plan on investing in REW/Umik in the future but for right now I used a free decibel reader on my IPhone and measured frequencies between 40 and 100hz using a frequency test on YouTube. I ran it at fairly low volume, but the volume was matched for each and the noise floor in my apartment was matched for each during the test. Here are the results:

Sealed:
40hz - 35db
45hz - 35db
50hz - 36db
55hz - 37db
60hz - 37db
65hz - 36db
70hz - 35db
75hz - 36db
80hz - 33db
85hz - 33db
90hz - 34db
95hz - 35db
100hz - 35db

Ported:
40hz - 36db
45hz - 36db
50hz - 38db
55hz - 40db
60hz - 41db
65hz - 41db
70hz - 40db
75hz - 40db
80hz - 35db
85hz - 34db
90hz - 35db
95hz - 35db
100hz - 33db

What would you guys do? Sealed for a little bit better cohesion or ported for the little extra bass?

 

[Sokel]

Hi, got some new speakers in and they came with optional port plugs. I did a very rudimentary experiment to see how they perform with and without the plugs. I plan on investing in REW/Umik in the future but for right now I used a free decibel reader on my IPhone and measured frequencies between 40 and 100hz using a frequency test on YouTube. I ran it at fairly low volume, but the volume was matched for each and the noise floor in my apartment was matched for each during the test. Here are the results:

Sealed:
40hz - 35db
45hz - 35db
50hz - 36db
55hz - 37db
60hz - 37db
65hz - 36db
70hz - 35db
75hz - 36db
80hz - 33db
85hz - 33db
90hz - 34db
95hz - 35db
100hz - 35db

Ported:
40hz - 36db
45hz - 36db
50hz - 38db
55hz - 40db
60hz - 41db
65hz - 41db
70hz - 40db
75hz - 40db
80hz - 35db
85hz - 34db
90hz - 35db
95hz - 35db
100hz - 33db

What would you guys do? Sealed for a little bit better cohesion or ported for the little extra bass?

3db is not a little extra,is a lot.
And since is down the lows where most power needed you will need to double it if EQ to be the same (or loose half the power if you lower everything else)

 

[Oski1928]

3db is not a little extra,is a lot.
And since is down the lows where most power needed you will need to double it if EQ to be the same (or loose half the power if you lower everything else)

I’m not sure I exactly understand your response. So your saying which is “better”?

 

[Sokel]

I’m not sure I exactly understand your response. So your saying which is “better”?

I'm not saying better or worst,I'm saying that in the 50-80Hz region there's a 3db drop in response when sealed.
If you want to compensate for that you have to use double the amp power to get the same response there when EQ'd.

 

[fpitas]

With ported the cone doesn't move as far at low frequencies, so doppler distortion is lower. But some people prefer the sound of sealed, or room gain causes too much bass when using ported. It's all compromises.

 

[Oski1928]

I'm not saying better or worst,I'm saying that in the 50-80Hz region there's a 3db drop in response when sealed.
If you want to compensate for that you have to use double the amp power to get the same response there when EQ'd.

Yea that I see, I didn’t know if the smaller difference in volume between frequencies would be more desirable though vs a larger gap (say the difference between 70 and 85hz, a 3db difference sealed vs a 6 decibel difference ported.)

 

[Oski1928]

With ported the cone doesn't move as far at low frequencies, so doppler distortion is lower. But some people prefer the sound of sealed, or room gain causes too much bass when using ported. It's all compromises.

Understood. Ik all that matters is what I like more, but wanted to see what people thought based off the numbers.

 

[DVDdoug]

It's flatter sealed but it's not that much different so it depends on how you like it.

You might see a more dramatic difference if you test lower. "Typically" you can get a lower -3dB frequency with a ported design (sometimes with a bump higher-up in frequency like you're seeing around 60-70 Hz)_but then the slope drops-off faster so at some point the curves cross and you get more output from the sealed design.

And "typically" the speaker is optimized for the volume and driver characteristics so you can't improve it by plugging a port or cutting a port in a sealed speaker.

 

[Zek]

but wanted to see what people thought based off the numbers.

I don't understand why people are obsessed with numbers ... simply try both in your environment, and you can also try a bundle of drinking straws to put in the bass reflex opening, and what suits the whole system better is to keep it.

 

[Ruhled]

I question the validity of these measurements. Surely 40hz wouldn't exhibit only a 1db measured difference between sealed and ported? I'd expect 6db or more of difference down there. If anything the reflex seems to exaggerate the bass a bit.

 

[JPA]

I used to have a pair of ported B&W Matrix speakers. At low to mid-high volumes everything sounded fine. At high volume the bass became bloated and farty. Probably port turbulence. I plugged the ports with Nerf balls and they sounded much better.

If I were you I wouldn't even bother measuring SPL. Just try them both ways and go with what sounds best.

 

[Robocop]

Go sealed ports. If you want more bass get active no ported subwoofer and connect with active crossover. This quote from Barry at Soundoctor:

"A port is ALWAYS nothing more than a cheap way to attempt to get free bass out of an enclosure and /or driver that's too small. It's a holdover from the 1930's when because of driver inefficiencies (especially when compared to today's units) you had to do everything possible to increase the useable output over the desired range of low frequencies."

 

[Beave]

Go sealed ports. If you want more bass get active no ported subwoofer and connect with active crossover. This quote from Barry at Soundoctor:

"A port is ALWAYS nothing more than a cheap way to attempt to get free bass out of an enclosure and /or driver that's too small. It's a holdover from the 1930's when because of driver inefficiencies (especially when compared to today's units) you had to do everything possible to increase the useable output over the desired range of low frequencies."

That's just, like, his opinion, man.

 

[RayDunzl]

What would you guys do?

Your SPL looks very low.

Blue line, more or less.

Like below the "threshold of hearin" according to the "threshold of hearing".

I'll assume the meter/mic was insufficient, and you could actually hear the tones you were testing.

 

[Oski1928]

I don't understand why people are obsessed with numbers ... simply try both in your environment, and you can also try a bundle of drinking straws to put in the bass reflex opening, and what suits the whole system better is to keep it.

Yea, Ik this is the answer lol. Still figured this was the place for numbers

 

[Oski1928]

Your SPL looks very low.

Blue line, more or less.

View attachment 290696

Like below the "threshold of hearin" according to the "threshold of hearing".

I'll assume the meter/mic was insufficient, and you could actually hear the tones you were testing.

yes I was hearing it. I can believe that the free iPhone app was not accurate.

 

[MaxwellsEq]

but for right now I used a free decibel reader on my IPhone and measured frequencies between 40 and 100hz using a frequency test on

I was in a hurry and used a highly regarded decibel meter on my iPhone. Later, at leisure I used a calibrated professional sound meter. The iPhone was only about right above 150Hz. Below that the numbers were wildly wrong. I suspect it's something to do with the size of the microphone in a phone.

 

[Head_Unit]

some new speakers

Make? Model? Here's my takes as a loudspeaker engineer:
- Ports are not always a "cheap attempt" though they often can be. It depends on the tuning.
- Around the port tuning, the resonance of the air in the port vibrating on top of the air in the box outputs more bass. BUT below the port tuning, it becomes a big leak, and the woofer unloads = moves a lot without producing much sound = distortion. So the tuning frequency is the big determinant.
- Yeah I doubt any SPL app is super accurate at the lowest or highest frequencies. Still, the relative dB's should hold up, so as @Ruhled noted it's odd that you get almost the same SPL...well come to think of it maybe not. Below the port tuning the SPL drops faster (24 dB per octave) in a ported than a sealed (12 dB per octave). Maybe that's the point at which they kind of even out so to speak.
- Here's another test-put on your favorite bass-heavy musics and crank them up as loud as you ever do. Are the woofer cones going nuts? Does it sound distorted? Then try with the port plugs. The opening heartbeat on Dark Side Of The Moon is another good test.

 

[MaxwellsEq]

Yeah I doubt any SPL app is super accurate at the lowest or highest frequencies. Still, the relative dB's should hold up, so as @Ruhled noted it's odd that you get almost the same SPL...well come to think of it maybe not

In my experience, cellphone based measurements didn't hold up at lower frequencies. I tried a couple of apps, including the NIOSH one which is well regarded. Compared with the professional calibrated SPL meter, the iPhone was a couple of dB out at 1kHz (across levels up to 85dB), but it was 12dB out (under reporting) at 80Hz. It was sufficiently wrong that it was simply unusable.

 

[Elkerton]

FWIW, Genelec I believe provide plugs for their speakers' ports, as does Revel with my M105s. The suggestion is to use the plugs when the speakers are placed close to a rear wall because of the amplification of the sound by the wall. I use them with my wee Revels to roll off the bass a little earlier to mate with my subs to control a room eigentone in the 90 to 95 Hz range.