Speaker design - sealed vs ported

[radovantz]

Hi everybody. I bought some USED Wharfedale Diamond 9 speakers. Noticed that mid-bass column in Diamond 9.5 floorstanders and Diamond 9.CM center speaker were completely sealed. There were no air pipes which allow air movement like the ones in Diamond 9.1 standmount speakers. I wonder if sealed cabinet can result as good as ported cabinet. Should I modify them with air pipes myself? Thanks..

Q added : Sealed or ported, which one is better?

 

[CnoEvil]

35 years ago, most speakers were sealed...which helps damp excessive movements of the bass woofer when using a TT. They are easier to place in a room and often have more accurate bass, but are less sensitive.

Ported speakers are easier to drive, generally have greater bass (for the same size cabinet). The implementation of the port and its tuning will determin how well they will sound.

 

[Vladimir]

Acoustic Suspension is generally better, however it eats up speaker efficiency and can have less boomy bass which some people prefer.

 

[MajorFubar]

Should I modify them with air pipes myself? Thanks..

No! Cocking about with them in this manner wil just f'k up the sound. If they were designed to be ported then they would be ported.

Q added : Sealed or ported, which one is better?

Neither are automatically better because there are too many other factors to consider. Ported speakers often sound like they have more bass for the same sized driver and cabinet, and moving them around with respect to boundaries has a much bigger influence on their perceived bass and tonal balance, especially rear-ported speakers. But until I bought a really good sealed speaker I didn't realise just how much coloration was being added to the sound by a port chuffing air out the box. However if you want bass you can feel in your chest, sealed speakers are probably not for you unless you can buy big expensive ones with huge drivers.

 

[radovantz]

Thanks for the input guys.. I remember that some manufacturers suppy special foam inside the air pipe (air duct). The salesman told me that it was to be placed inside the air pipe to eliminate excess boomy sound, in case it happen in your environment, but I did not believe him. I thought the bass driver might tear if the cabinet was blocked. And I thought the foam was a pakaging material only.

Since I read your comments, now I am confident to examine both ported and sealed methods. So far, I have no problem with bass quality came out from the sealed mid bass cabinet of my Diamond 9.5 and 9.CM. Now I can see my actual problem, is to solve excess bass from ported cabinet. I just block the air pipe at the rear side of Diamond 9.5 with a bunch of clothes, which is driven by lower bass driver. Then boomy problem is immediately solved, and bass quality is better.

Next move is to try Diamond 9.1, because it produce boomy sound too in my room. Diamond 9.1 would be more difficult because it is front ported.

 

[Vladimir]

Try the straw method by adding a bunch of drinking straws in the port instead of fully blocking it. Also try very loosly packed cotton or anything as light and transparent for air movement.

Generally you never get better sound (though you may think so at first) when you outright plug and block a ported speaker. But minor adjustments to the airflow can improve things depending on room, positioning, tastes... In other words throttle it, don't just stuff it.

I sent you a video link in my previous comment that briefly explains that there is different engineering going on between ported, infinite baffle and acoustic suspension. Like MajorFubar mentioned, you can't just switch between different design concepts by just pluging the hole. A lot more is going on there.

 

[sheggs]

Thanks for the input guys.. I remember that some manufacturers suppy special foam inside the air pipe (air duct). The salesman told me that it was to be placed inside the air pipe to eliminate excess boomy sound, in case it happen in your environment, but I did not believe him. I thought the bass driver might tear if the cabinet was blocked. And I thought the foam was a pakaging material only.

Since I read your comments, now I am confident to examine both ported and sealed methods. So far, I have no problem with bass quality came out from the sealed mid bass cabinet of my Diamond 9.5 and 9.CM. Now I can see my actual problem, is to solve excess bass from ported cabinet. I just block the air pipe at the rear side of Diamond 9.5 with a bunch of clothes, which is driven by lower bass driver. Then boomy problem is immediately solved, and bass quality is better.

Next move is to try Diamond 9.1, because it produce boomy sound too in my room. Diamond 9.1 would be more difficult because it is front ported.

What you are referring to are transmission line speakers. Which are different than sealed or ported. PMC have a bit of an article about it on their website - https://pmc-speakers.com/support/faq-page/how-do-transmissions-lines-differ-ported-and-vented-speakers

 

[chebby]

Acoustic Suspension is generally better, however it eats up speaker efficiency and can have less boomy bass which some people prefer.

Nice source of videos there. (AES Oral History) thanks.

I have always been a bit of a fan of Ed Villchur (and owned a couple of his products).

The AR18s were not my first pair of speakers but they were my favourites for many years.

 

[Benedict_Arnold]

Diamond 9.1 would be more difficult because it is front ported.

Just use CLEAN socks in case your mum comes round