sealed vs. port cabs

[SLIV]

Generally, sealed cabinets are made by unicorns and ported cabinets by leprechauns. I hope that helps.

FINALLY, some real information!

I have a Bag End that is front ported (rectangular shape) but came with a seal for it. I've never used it but now I'm thinking about giving it a shot. What puzzles me is that a cabinet is generally built or tuned to be ported or sealed, but what is happening with cabs that are meant to be both? Poor compromise?

Great discussion-- very informative, folks.

 

[rodl2005]

Either of the BERG. NV cabs- 412 or 610 will be SUPERB w/ the Mesa 400+ IMO. they sound great with SVT's, Fender 300PRO, V4's, YBA200's, MArshall Superbass- all tube amps!!!!! Well the NV610 & 215 do anyway.. I aint got a 412 to try :-(

 

[fdeck]

FINALLY, some real information!

I have a Bag End that is front ported (rectangular shape) but came with a seal for it. I've never used it but now I'm thinking about giving it a shot. What puzzles me is that a cabinet is generally built or tuned to be ported or sealed, but what is happening with cabs that are meant to be both? Poor compromise?

Great discussion-- very informative, folks.

There are drivers that are reasonably happy in either sealed or ported cabs. Closing the port will give the speaker less low end and probably reduced power handling at the lowest frequencies. That option, while it seems offensive to everything good and moral in the world, can be useful when working in rooms that have really bad acoustics.

 

[skinnypete]

Some one told me that there is more of chance for speaker damage if you are using an all tube amp with a ported cabinet. Is this true?

 

[billfitzmaurice]

Some one told me that there is more of chance for speaker damage if you are using an all tube amp with a ported cabinet. Is this true?

Not true. However, there is more potential for damage with drivers that have very low Qts values, less potential for damage with drivers that have very high Qts values. Since low Qts drivers are usually used in ported cabs and high Qts drivers in sealed there is some basis in fact behind this particular myth, but not enough to make it true.

 

[tombowlus]

FYI, Anthony Lucas (from Eminence) will feature this topic in his column in issue #4 of Bass Gear Magazine (which should be out around the end of September).

 

[skinnypete]

Thanks. What is a QT value and how do I find out if the driver currently housed in the ported cab I use has a high or low?

 

[billfitzmaurice]

Thanks. What is a QT value

http://www.eminence.com/resources/data.asp

and how do I find out if the driver currently housed in the ported cab I use has a high or low?

Chances are you can't. Manufacturers are very tight lipped about what drivers they use and the specs on them, ostensibly to protect their designs. That's silly, as anyone who wants to know what they are can get a cab, pull a driver and test it. But you need the testing equipment.

 

[skinnypete]

Thanks for the information.

 

[Rickles]

Does anyone remember the port plugs that came with Trace Elliot's...you could either have sealed or ported.

There are drivers that are reasonably happy in either sealed or ported cabs. Closing the port will give the speaker less low end and probably reduced power handling at the lowest frequencies.

Here's my question. I have an SVT-CL, SVT-410HE (sealed), and SVT-210HE (rear ported). I recently added the 210 to balance out the Ohms. I've been planning to remove the port tubes and use caps to seal the ports thinking this would turn it into a sealed cab like the 410 so they would be matched. Will I screw things up, acoustically, or will this do what I'm thinking? Or, will I not be able to hear a difference anyway? You can see in my avatar pic above that the 210 just sits on its side next to the 410; does it matter that it isn't stacked on top?

 

[billfitzmaurice]

Will I screw things up, acoustically

You will.

thinking this would turn it into a sealed cab like the 410 so they would be matched.

They won't be matched, because the drivers are different.

You can see in my avatar pic above that the 210 just sits on its side next to the 410; does it matter that it isn't stacked on top?

It does matter. Do a forum search of 'vertical'.

 

[eadg98005]

Subscribed.

 

[Rickles]

Thanks, Bill, I'm going to take your advice: leave the ports alone and stack 'em. I did the 'vertical' search and read one poster who has the same setup as me, albeit VR instead of CL. Rick

 

[stiles72]

Just to piggy back on what everyone else has said...

Ported cabs breathe, and reproduce lower frequncies. More boom, and more bass you can "feel". Sealed cabs are more focused and mid-rangey. I'm a big Ampeg proponent but have yet to play through a sealed 410 or 810 that I like. They lack "umpffff". I play through ported 2x15 cabs, the B-100R and a 63 Portaflex, and carve out my own sonic space lower in the EQ spectrum - rather than trying to "cut" through or compete with the guitars.

 

[Growly Lytes]

Anthony Lucas knows all. I totally trust everything he told me about the BP102.I explained what i was doing with my DIY cabs.Told him what power i use & what i expected from my cabs. I asked about the whole range of Eminence bass speakers & he said for what im going to do i would be best off using the BP102. They need room to operate properly, they are heavy duty speakers no matter what way you look at it.After i ported the cabs going on Anthony Lucas`s advice, it gave me some good midrange freq but was boomy, i dont think i told him the exact size of the cabs. I then was contacted by the Agedhorse that roams these threads. He actaully pointed me in the perfect direction what a champion !! The results were just incredible no crap brothers. Theres no reason to lie when i have great results. My 2 410 cabs now rumble like crazy with massive low-end.The high top-end is not very present but i `never` did like the sound of high freq.I counter the missing high with added high mids via the parametric eq & wholla. Sounds like a piano !
A few fellows here just cant get the head around the fact that what ive done works execellent.Sure at first i wasnt sure but now i have a monster sounding rig.