Off-topic somewhat but when playing around with tuning ports using different length tubes I realised that tuning left and right speakers to different frequencies can actually work. (I am of course assuming that low bass is a mono signal on most recordings.) If you think of it it does have its advantages: You can tune to a wider frequency range rather than having to settle on a narrower one. There'll be less of a boost but a more uniform one. If you have to place your speakers asymmetrically putting one of them close to a boom-prone corner, you can put the longer port tube in that one, tuning it lower and providing more control over the mid-upper bass where things can more easily get out of hand. I don't think anyone else has tried that before, so you heard it here first :)
Yes, you can do these experiments, including if you want to find out the actual tuning of the cabinet. If you use a port that is too large (acoustically speaking) for the speaker, you will notice that after a certain size the port will start to lose its function of producing sound, because it will be tuned to a frequency below the tuning of the speaker box. If you use ports that are smaller than the original port, the box will reproduce higher frequency bass and will have less extension and depth, but it will play these bass at a slightly louder volume than the speaker with the original port.
Implied but not said is the matter that below the port resonance air flows freely into and out of the port (hence the greater excursion) But it is out of phase with the woofer cone, which causes acoustic cancellation and a much sharper roll off in frequency response. Thus plugging the port usually results in a bit less but deeper bass. This is an easy test... turn off your subwoofer(s), now listen to some music with deep rumbling bass in it, at mid-loud levels... putting your hand over the port will usually result in less overall bass but more deep bass, since you've stopped the cancellation effect. Like all things audio, a little science helps, but the end result is usually a judgement call.
I don't like boomy bass. But the plugs I tried on my dynaudio speakers justcdidnt sound right. For some reason it made the sound worse. So. No plugs for me
Honestly, the idea of restricting the diameter of the resonance duct or even clogging it with certain acoustic materials to reduce the excess bass and sub-bass of an acoustic cabinet in certain environments seems stupid. That's what frequency band equalization is for. And regarding the idea that I saw someone mentioning, of using acoustic materials inside the duct to make the box have deeper bass, I wouldn't recommend it if you don't know the equipment you have well, as it can cause several inconveniences such as the blowing effect (the air moving at a very high speed inside the portico), moderate to drastic changes in the frequency response of the acoustic cabinet, etc. If you have a box that doesn't sound smooth and pleasant and doesn't have acoustic absorbent material inside, try using such materials. It doesn't need to be anything special, just take up the entire interior of the box without taking up too much of the cabinet's actual volume. I tested this using pillow stuffing - which resembles glass wool - and it worked so well in my speaker that it completely changed the frequency response for the better (it attenuated the unwanted bass frequency response from 120 Hz and above, and gave a boost in the performance of the sub-bass frequency response from 70 Hz to 30 Hz), compared to the factory model with no acoustic material inside.
I reckon not quite enough bass is good and just a bit too much is also good. But what I reckon is BAD is just the right bass level. The bass (for me) simply "disappears" with the right level and is so unengaging! I usuually go for just a bit too much bass (by one percent) so you can hear the bass. I build speakers as a serious hobby. When not quite enough bass, you can hear it more than the right level, and bass is tight and fast but won't rock thefloor (but way better than the right level). Good for chamber music. 😅 Crazy as it seems but this happens with all my speaker builds and it's like that with my B&W 706 reference speakers. I ran the woofers only and had an open FR driver on the med and treble and it was like one percent less output than the B&W tweeter, and I didn't realise how GOOD the bass is on the 706s, way more FUN to listen to the bass on those speakers (with one percent more bass level). And the bass was louder but didn't even sound louder, just way more "punchy", so it was louder. With my B&Ws original, though, the bass (being the right level) was so uninteresting and unengageing compared to my experiment bass level. 😅
Port plus will not destroy your speakers. Ports will not destroy your speakers. Excessive volume and especially at bass frequencies might. Volume which is generally controlled by the user ;-) That said usually a sealed speaker will have its largest excursion points at a different frequency than a ported speaker, so you should simply test with sine waves etc at a sensible level. People should also consider limiting the maximum volume outputtable so that there is less chance of accidentally blasting the speakers
Not really. There are no simple answers to complex questions. No one is going to stop you from using port plugs if you want to, but this is not the smartest way to 'prevent mechanical damage to a speaker due to overexcursion', because with a simple equalizer or independent volume control, in the case of an active speaker, you can solve problems of excessive bass in the room and overexcursion of the speaker. After all, this will generate other inconveniences, from a weakening of the sound quality to even physical damage to the transducer (possibility of damage to the cone, the surround and the voice coil), if you happen to use this speaker with a port plug at maximum volume. These problems can vary depending on the equipment in which these port plugs are used. If you have a cabinet with a transducer mounted in it in such a way that it becomes a dedicated speaker for bass and sub-bass frequency response (say, from 200 Hz to 20 Hz), that is, a good quality subwoofer, you don't need to worry about the transducer's excursion, unless you are sending excessive power to the transducer, listening to music with a lot of distortion - square waves - in the bass, or if you want it to respond below 20 Hz. Now, if you have a box composed to respond from higher frequencies - a bookshelf, for example, don't try to make it respond below the minimum determined by the equipment manufacturer. If you are a DIY hobbyist and are assembling your bass cabinet, look for a transducer that has T/S parameters that favor the reproduction of low frequencies without damaging the product, within the ideal power specified. By following this, you won't have to worry about damage due to transducer excursion.
What type of port plugs do you provide for the Torii bookshelf, are they 0% or 100% blocking or are they like the KEF ones where they're a two-piece design to provide some adjustability? Also, are they open or closed cell foam? Thanks!
We haven't historically provided any plugs but what we are looking at is an open cell. It would be one piece but blocks enough airflow that somewhere between a sealed and aperiodic design.
Probably making the speaker lasts longer cause it doesnt extend as much. Like when you put a reg speaker in an infinite baffle and it over extends and breaks
See our video here: www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=www.youtube.com/watch%3Fv%3Dv_3jgnInhiI&ved=2ahUKEwi20br1m8CHAxVCnokEHUcIAC8QwqsBegQIDxAG&usg=AOvVaw2Z9EQe8Q_QM8ccVvq1Vk1V Just keep the vertical and horizontal location the same and you can move it to the front without any issues.
@@nathaneldogo Subwoofer amps are sealed on the internal side and cooling is usually provided via external heat sinks. In general, my experience has been that plate amps tend to have a high failure rate due to the heat and vibration no matter if the subwoofer is vented or sealed.
Provided that you can still "see their tonsils", then I agree. But that never happens. Only a sub (with your speakers) can make as much bass as you want without spoiling the med and treble. I reckon. 🎉
Been rockin the dirty sock trick for years, finally built proper removable seal
Off-topic somewhat but when playing around with tuning ports using different length tubes I realised that tuning left and right speakers to different frequencies can actually work. (I am of course assuming that low bass is a mono signal on most recordings.) If you think of it it does have its advantages: You can tune to a wider frequency range rather than having to settle on a narrower one. There'll be less of a boost but a more uniform one. If you have to place your speakers asymmetrically putting one of them close to a boom-prone corner, you can put the longer port tube in that one, tuning it lower and providing more control over the mid-upper bass where things can more easily get out of hand. I don't think anyone else has tried that before, so you heard it here first :)
Yes, you can do these experiments, including if you want to find out the actual tuning of the cabinet. If you use a port that is too large (acoustically speaking) for the speaker, you will notice that after a certain size the port will start to lose its function of producing sound, because it will be tuned to a frequency below the tuning of the speaker box. If you use ports that are smaller than the original port, the box will reproduce higher frequency bass and will have less extension and depth, but it will play these bass at a slightly louder volume than the speaker with the original port.
Implied but not said is the matter that below the port resonance air flows freely into and out of the port (hence the greater excursion) But it is out of phase with the woofer cone, which causes acoustic cancellation and a much sharper roll off in frequency response. Thus plugging the port usually results in a bit less but deeper bass.
This is an easy test... turn off your subwoofer(s), now listen to some music with deep rumbling bass in it, at mid-loud levels... putting your hand over the port will usually result in less overall bass but more deep bass, since you've stopped the cancellation effect.
Like all things audio, a little science helps, but the end result is usually a judgement call.
Just found your channel and subscribed. You gave a competent and thorough answer. Thanks!
No problem. Glad it was helpful.
For those new to such antics foam pipe insulation or pool noodles are cheap and don't hurt anything.
I like what I hear from your speakers. U should make theater specific diy speakers
The third type is a can of vienna sausages wrapped in a black sock.
Useful vid, thanx.
I don't like boomy bass. But the plugs I tried on my dynaudio speakers justcdidnt sound right. For some reason it made the sound worse. So. No plugs for me
Honestly, the idea of restricting the diameter of the resonance duct or even clogging it with certain acoustic materials to reduce the excess bass and sub-bass of an acoustic cabinet in certain environments seems stupid. That's what frequency band equalization is for.
And regarding the idea that I saw someone mentioning, of using acoustic materials inside the duct to make the box have deeper bass, I wouldn't recommend it if you don't know the equipment you have well, as it can cause several inconveniences such as the blowing effect (the air moving at a very high speed inside the portico), moderate to drastic changes in the frequency response of the acoustic cabinet, etc.
If you have a box that doesn't sound smooth and pleasant and doesn't have acoustic absorbent material inside, try using such materials. It doesn't need to be anything special, just take up the entire interior of the box without taking up too much of the cabinet's actual volume. I tested this using pillow stuffing - which resembles glass wool - and it worked so well in my speaker that it completely changed the frequency response for the better (it attenuated the unwanted bass frequency response from 120 Hz and above, and gave a boost in the performance of the sub-bass frequency response from 70 Hz to 30 Hz), compared to the factory model with no acoustic material inside.
Totally agree
I reckon not quite enough bass is good and just a bit too much is also good. But what I reckon is BAD is just the right bass level. The bass (for me) simply "disappears" with the right level and is so unengaging! I usuually go for just a bit too much bass (by one percent) so you can hear the bass. I build speakers as a serious hobby. When not quite enough bass, you can hear it more than the right level, and bass is tight and fast but won't rock thefloor (but way better than the right level). Good for chamber music. 😅 Crazy as it seems but this happens with all my speaker builds and it's like that with my B&W 706 reference speakers. I ran the woofers only and had an open FR driver on the med and treble and it was like one percent less output than the B&W tweeter, and I didn't realise how GOOD the bass is on the 706s, way more FUN to listen to the bass on those speakers (with one percent more bass level). And the bass was louder but didn't even sound louder, just way more "punchy", so it was louder. With my B&Ws original, though, the bass (being the right level) was so uninteresting and unengageing compared to my experiment bass level. 😅
Port plus will not destroy your speakers. Ports will not destroy your speakers.
Excessive volume and especially at bass frequencies might. Volume which is generally controlled by the user ;-)
That said usually a sealed speaker will have its largest excursion points at a different frequency than a ported speaker, so you should simply test with sine waves etc at a sensible level.
People should also consider limiting the maximum volume outputtable so that there is less chance of accidentally blasting the speakers
So in essence, plugging the port actually prevents mechanical damage instead of causing it by dampening wild swings of the woofer-cone….
Generally speaking, yes.
Not really. There are no simple answers to complex questions.
No one is going to stop you from using port plugs if you want to, but this is not the smartest way to 'prevent mechanical damage to a speaker due to overexcursion', because with a simple equalizer or independent volume control, in the case of an active speaker, you can solve problems of excessive bass in the room and overexcursion of the speaker. After all, this will generate other inconveniences, from a weakening of the sound quality to even physical damage to the transducer (possibility of damage to the cone, the surround and the voice coil), if you happen to use this speaker with a port plug at maximum volume. These problems can vary depending on the equipment in which these port plugs are used.
If you have a cabinet with a transducer mounted in it in such a way that it becomes a dedicated speaker for bass and sub-bass frequency response (say, from 200 Hz to 20 Hz), that is, a good quality subwoofer, you don't need to worry about the transducer's excursion, unless you are sending excessive power to the transducer, listening to music with a lot of distortion - square waves - in the bass, or if you want it to respond below 20 Hz.
Now, if you have a box composed to respond from higher frequencies - a bookshelf, for example, don't try to make it respond below the minimum determined by the equipment manufacturer. If you are a DIY hobbyist and are assembling your bass cabinet, look for a transducer that has T/S parameters that favor the reproduction of low frequencies without damaging the product, within the ideal power specified. By following this, you won't have to worry about damage due to transducer excursion.
@@netorodrigs2100 You got way too much time on your hands😮
What type of port plugs do you provide for the Torii bookshelf, are they 0% or 100% blocking or are they like the KEF ones where they're a two-piece design to provide some adjustability? Also, are they open or closed cell foam? Thanks!
We haven't historically provided any plugs but what we are looking at is an open cell. It would be one piece but blocks enough airflow that somewhere between a sealed and aperiodic design.
Probably making the speaker lasts longer cause it doesnt extend as much. Like when you put a reg speaker in an infinite baffle and it over extends and breaks
Some drivers are made for close, bass reflex, horn infinite speakers that’s it
can i put a 2tdx kit into a cabinet with a front port? how does the sound different between front ported and rear ported?
See our video here: www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=www.youtube.com/watch%3Fv%3Dv_3jgnInhiI&ved=2ahUKEwi20br1m8CHAxVCnokEHUcIAC8QwqsBegQIDxAG&usg=AOvVaw2Z9EQe8Q_QM8ccVvq1Vk1V
Just keep the vertical and horizontal location the same and you can move it to the front without any issues.
@@css_audio ty you rock!
Built seals for full marty ports.
We can’t plug port in a amplifier subwoofer ?
You can plug the port on a subwoofer the same way as on a speaker and it has the same effect.
@@css_audio The subwoofer amplifier does not heat up because the port is covered 🔥?
@@nathaneldogo Subwoofer amps are sealed on the internal side and cooling is usually provided via external heat sinks. In general, my experience has been that plate amps tend to have a high failure rate due to the heat and vibration no matter if the subwoofer is vented or sealed.
@@css_audio thanks
Cheap class d amps
The speakers are going to be OK, but the speaker cables gonna bloat. All that energy can't get out!
Just roll off from 40hz down
Used socks will definitely destroy your nose😅
Too much bass? NEVER!!!
Provided that you can still "see their tonsils", then I agree. But that never happens. Only a sub (with your speakers) can make as much bass as you want without spoiling the med and treble. I reckon. 🎉
Plugging a ported speaker usually makes them sound crap