# port blockers...what exactely are they doing?



## pietsch288 (Sep 10, 2006)

Right now I am running my cs-ultras with no ports blocked because that gives me the most FEEL between 14-18hz but that doesn't seem right..... shouldn't I get more "output or feel" at those freq by adding 1 blocker so the ultras are tuned to 16hz?? Also it seems like I have port noises when I add blockers.......So....what exactely are the port blockers doing?? thanks rich


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## Ed Mullen (Jul 28, 2006)

pietsch288 said:


> Right now I am running my cs-ultras with no ports blocked because that gives me the most FEEL between 14-18hz but that doesn't seem right..... shouldn't I get more "output or feel" at those freq by adding 1 blocker so the ultras are tuned to 16hz?? Also it seems like I have port noises when I add blockers.......So....what exactely are the port blockers doing?? thanks rich


Plugging one port lowers the system tuning frequency from 20 Hz to 16 Hz and improves extension and output in the 13-18 Hz band. It also reduces max output in the 20-32 Hz band, which is what you perceive as a loss of slam/impact/pressure. 

For most HT applications, running all ports open in the CSU will provide the best performance over the most common bass frequencies encountered on DVDs. There is far more bass present in the 20-32 Hz band than in the 13-18 Hz band. If you are running the system hard and looking for the most slam/impact with the least amount of port noise, the 20 Hz mode is always best for the CSU.


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## Moonfly (Aug 1, 2008)

pietsch288 said:


> Right now I am running my cs-ultras with no ports blocked because that gives me the most FEEL between 14-18hz but that doesn't seem right..... shouldn't I get more "output or feel" at those freq by adding 1 blocker so the ultras are tuned to 16hz?? Also it seems like I have port noises when I add blockers.......So....what exactely are the port blockers doing?? thanks rich


I think there are a couple kinds of impact you get from as sub. There is the real low down grunt, room rumbling stuff, then there is the profound upper bass slam that gives you more of a punch in the chest feel. The lower you try to focus your sub the less you feel the upper slam. Sometime people focus so much and getting really low clean output they start to loose a bit of the upper sub bass impact, and it can take time to realise this I think.

You cant go wrong following Ed's advice.


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## pietsch288 (Sep 10, 2006)

Funny you say that....I've been playing around again for a couple of days and have noticed exactly what you said....the more I focus on boosting 14-16hz about 5-8db more than 20-30hz and then sloping 30-80hz really steep the more I love it. Espically when trying to get gut wrenching bass. When I set it up like this... I get the feel/impact I'm looking for without compromising any clairity. Its almost like not having the subs on.... except I can feel them.


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## Ashmanuk (Sep 14, 2007)

I Have two PC Ultras running through the Audyssey Sub EQ sub's set to sealed all ports blocked and i do get very good impact, but if i was to re EQ at sat 15Hz tune "one port blocked" would this give me better mid-range bass and louder ? 
I have them set to sealed as i felt this sounded very good for music but this was before i had the Sub EQ maybe i need to re look at this what do you guys think ??

Regards

Paul


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## Moonfly (Aug 1, 2008)

Personally, I had my Ultra sealed for some time as I found it very accurate. Over time though I found the Ultra a bit quiet musically for my tastes, and changing to a 15hz tune helped a little bit. You might like it, you might not, but as always you should try it and decide for yourself.


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## stevefish69 (Dec 9, 2006)

Personally i'm now thinking about unplugging my PC-Ultra back to stock 20Hz tune and re-doing the Sub EQ as the Quake Q10B now offers the desired effect from 5Hz upwards. I've never run it in it's native tune so it'll be nice to see how it differs further up the bass scale unrestricted. I just hope that those waves of room pressurising sub bass waves on the ultra low stuff does not dissapear althogether.

Has your Quake been delivered yet Moonfly


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## Moonfly (Aug 1, 2008)

stevefish69 said:


> Has your Quake been delivered yet Moonfly


Ive not got round to completing the transaction yet. I keep forgetting at night when I get on the forums :duh:, plus I think subconsciously, because everyone else's arrived in super quick time it's removed the sense of urgency so I keep forgetting. Something I'm bad at really.

Add to that my sub isnt running, and its a bad combination when it comes to getting my proverbial in gear . I must remember to sort it ASAP, but I'm in the office at the min


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