Difference between front and rear ports?

[MUSHROOMSeAcOw]

I did a few searches on this topic, but couldn't find a straight answer. Basically, I'm buying a new Markbass 2x10 cab, and my choices seem to be the Traveler 102P Rear-Ported and the Standard 102HF Front-Ported. The only difference I can see the porting and the piezo tweeter on the Traveler.

My main question is what effect the porting has on the overall sound. I have heard that front ports give better low end response, but I could not find any solid explanation. Is the front port worth an extra $50 and a 3-week wait?

[BassBob1]

I can't answer your question but i once owned the 102P and unless the you want the slightly more portable of the two. The 102HF IMO is a better sounding cab especally if you are going for a stand alone 210. Though IMO you for that money you should look at other cabs too (if you haven't already).

[5StringBlues]

The front port 102HF goes down to 40 Hz.

Rear port Traveler goes down to 45 Hz.



I've not played the Traveler but I'd imagine the 102HF to be stronger in the lows.




Edit:The whole frenquency response is wider with the 102HF. It goes up to 20 Khz,whereas the Traveller goes to 18 Khz.

[JimmyM]

Difference between rear and front ports...one is in the rear, one is in the front. Otherwise there is no difference whatsoever since port location doesn't matter.

However, there are differences in the Markbass cabs rear and front ported, but only because of cab size...the front ported cabs are bigger and have more low end.

[Mike Arnopol]

I think that port location does matter. If one is playing where the cab needs to be against the wall there can be too much reinforcement by the back wall. No big deal if you have a parametric, but with a bass control you have to turn the bass down to bring it in balance. Problem is that with most bass controls you lose can also be turning down mid and possibly upper bass.

[JimmyM]

Originally Posted by Mike Arnopol

I think that port location does matter. If one is playing where the cab needs to be against the wall there can be too much reinforcement by the back wall. No big deal if you have a parametric, but with a bass control you have to turn the bass down to bring it in balance. Problem is that with most bass controls you lose can also be turning down mid and possibly upper bass.

Port frequencies are omnidirectional, so it doesn't matter where they come from. All you need from a wall when using a rear ported cab is just enough space to keep the port from getting stuffed, and then a front port will behave exactly the same by that wall as a rear port. This is scientific fact backed up by tons of research on the subject and not just opinion.

[will33]

+1

Location of a rear port can matter if it's directly behind the speaker. Some of the mids/highs off the back of the cone can "fly out" through the rear port instead of getting reflected back towards the listener.

Yes the back wall can stuff it if too close but I'm wondering now if there isn't some precise distance in relation to port area where the wall would serve as an extension of the port essentially lowering the cab tuning or if just the same rules for boundry effects apply.


Point is port your cabs in the front and you don't have to worry about it....if you don't have enough room in the front for some ports you're probably stuffing too much speaker in too little box.

[billfitzmaurice]

Originally Posted by MUSHROOMSeAcOw

My main question is what effect the porting has on the overall sound. I have heard that front ports give better low end response, but I could not find any solid explanation. Is the front port worth an extra $50 and a 3-week wait?

Port location is moot. MarkBass tends to use rear porting in cabs that are too small to fit them on the front. A smaller cab equals less low end. Size matters, port location doesn't.

I think that port location does matter. If one is playing where the cab needs to be against the wall there can be too much reinforcement by the back wall.

Since port radiation is omni-directional, and for that matter so is cone radiation below roughly 200Hz, there will be absolutely no difference.

[countrybass007]

I could never hear a real difference, now Jimmy and Bill have told me why. Thanks!

[MUSHROOMSeAcOw]

Thanks for the answers guys. I think I've made my decision.

[Bob Lee (QSC)]

Originally Posted by JimmyM

Port frequencies are omnidirectional, so it doesn't matter where they come from. All you need from a wall when using a rear ported cab is just enough space to keep the port from getting stuffed, and then a front port will behave exactly the same by that wall as a rear port. This is scientific fact backed up by tons of research on the subject and not just opinion.

+1

[BassmanPaul]

Juat to add a modicum to the conversation, as long as your cabinets are six to eight inches away from any wall you'll be fine. My Acme B2s are rear ported.

[Marko5657]

My understanding is as stated above, but Saturday-night’s gig just popped into my mind…

outdoors under an open tent, rig at one end facing across stage.

No wall there for anything to bounce off of.

Would not a front-ported cab benefit the stage more than a rear-ported, as I’m just picturing that going off into the night?

[BassmanPaul]

Post #8 says it all quite succinctly I think.

[alexclaber]

No, all the low frequency output from the speakers and ports is omnidirectional, regardless of where they point. Indoors all cabs benefit (and suffer) from boundary reflections, outdoors all cabs have no boundaries bar the ground to help (or hinder).

[Marko5657]

Thinking about it, I kinda have a feeling there is some difference.

If all were that simple, why is subwoofer placement critical if those frequencies just kinda fill everything equally?

Why bother placing your cab(s) facing any particular direction? Just stick them anywhere pointing in any direction and they’ll be fine, no?

Sound comes out of those ports; if you had your choice where to send that sound, would you not aim them in the same direction you aim your speaker(s)?

There are plenty of stages where there’s not just a wall behind your rig, outdoors under an open tent, and some indoor stages where there are people off to that side before any wall.

I’m thinking maybe they use rear ports only where there’s no room up front for a reason.

Edit to note that I place my cab(s) at one end of the stage facing across stage.

[ddbassGA]

Counter-intuitive to be sure. But I've heard and used plenty of good rear ported cabs and front ported cabs. (Bad ones of each design too). What I haven't ever heard is the same box, driver, etc front versus rear ported, that is "all things being equal" except port location.

I prefer front port so I don't have to worry about blocking the port when the cab is against the wall (like in my practice space). But really it doesn't take 6" to alleviate that concern.

[alexclaber]

Mark, it doesn't matter at all where the ports point. But the distance between sound source and reflective boundaries is critical. Port output is omnidirectional, not omnipresent! Read the tech info and magazine articles on my website for more in depth enlightenment.

[Marko5657]

I guess if the frequencies coming out of the ports are all that low, the volume of which is the same around the cab, then that makes sense.

[Passinwind]

Originally Posted by ddbassGA

What I haven't ever heard is the same box, driver, etc front versus rear ported, that is "all things being equal" except port location.

I have. Didn't make a lick of difference.