Ported cabs sound different above vs. below resonance

[S-Bigbottom]

The essential rule, in my opinion, is that if a cab is ported it must be tuned so low that you never hear the range of frequencies where the ports "give up the ghost" (to put it very kindly). To do this and keep full-range with only one cab, there are very few choices. One cheaper option is to retune a normal cab, but you have to know what you're doing.

A problem with using only one ported cab tuned extra low is that it usually becomes inefficient (this is less of a problem if, in accordance with TalkBass orthodoxy, you don't mind if 41Hz is rolled off (but you still insist that it sound good)). It seems to get darker too.

So, if done with two cabs, the *other* cab probably must be sealed. A Rumble 115 with both ports blocked would serve very well if you like its old-fashioned tone (I do). The loudness in the mids and highs (where most "tone" is) is still good, and the other cab takes the lows. Of course you might have to switch to a driver more suitable for sealed cabinets. I didn't.

A stereo power amp could be used if the sensitivity of the two cabs don't coincidentally coordinate as desired.

Two ported cabs the exact same will boost your lows making the sound fuller down low as well as boost everything else.

Why neuter one cabs lows?
Your mixing is giving mixed results.

As your example, just stack two Rumble 1x15's with NO modifications. This is the easiest way to get a 6db boost in all frequencies. Especially lows.
You will get your E-Bomb as well as more everything else at less volume.

 

[S-Bigbottom]

Thank you as always for the warning. I'll try to find a dip.
But I never claimed to have a lot of experience and already denied having any expertise.

But I think what you said might not matter if only one cab is dominant down there, which can be enforced with EQing.

Two of the same cabs not altered will not need odd and compensation eqing and volume levels. They both can take what you adjust on your amp head evenly, while you get a boost of more lows and mids with less volume overall than with a single cab.

 

[LetItGrowTone]

I'm not talking about the *quantity* of 41Hz, which could be corrected with EQing.
I'm talking about a *quality* of 41Hz which EQing can't fix.

-Ported cabs sound different above vs. below (cabinet) resonance. Seems to be a fact.
-It sounds *worse* below resonance. This is an opinion that seems to be true.
-If so, my fix is to tune it below the fundamental of the lowest note to be played, so the transition between above and below is never heard.

 

[agedhorse]

I'm not talking about the *quantity* of 41Hz, which could be corrected with EQing.
I'm talking about a *quality* of 41Hz which EQing can't fix.

Neither of these are correct statements.

 

[LetItGrowTone]

-Ported cabs sound different above vs. below (cabinet) resonance.
This seems to be a fact.
For anyone wanting to hear it most clearly, I described a simple test in the first part of the original post.

-It sounds *worse* below resonance.
This is an opinion but I think most people would agree with it.

-I suggested the solution, and gave an example using two cabs, but I should have kept things simpler and just said that the ported cab I named ALONE fixed the problem, because it has no above/below transition within the frequency range of single notes on a four string bass (or even five string).

I offered my observations, and I'm very happy to have solved a longstanding problem.

 

[agedhorse]

Ok, you officially win!

 

[LetItGrowTone]

I solved the mystery, yes, thank you.

 

[Wasnex]

Years ago I played an SWR RedHead for a year or two. The lows sounded really HiFi: deep, even, focused, fast. But in the mix this amp had a tendency to disappear IMHO. My recollection is the cab was ported super low; something like 19hz.

I added a Big Ben (18"). To my ears the Big Ben didn't seem to play very deep, but it added some punch in the low mids that was missing from the RedHead. I won't necessarily say the sound quality was better with both cabs, but it was definitely a lot easier to hear in the mix, which is IMHO more important.

My approach evolved over the years. My observation is there is often a trade off between fat down low and clarity/focus in the mids. I am more concerned with clarity and focus than fat, so I tend to run fairly lean on the lows. This approach works really well with some cabs...and not so well with others.

I guess the lesson is "It's complicated."

 

[12bass]

I solved the mystery, yes, thank you.

Think I hear what you're saying. My fEARful T3W 15/6/1 goes deeper than the average bass cabinet, and I prefer to hear those fundamental frequencies over just having the 1st overtone. I know what you mean about how ported cabinets lose the fundamental as you go below their port tuning frequency. I can hear it as a thinning-out of tone as you go down. A full low-B fundamental sounds quite different, and more satisfying, than a 1st overtone B, though even the fEARfuls struggle with that. Using a HPF has significant practical value in the real world of high volume bass reproduction, but it isn't superior to my ears. If only the laws of physics didn't make reproducing those fundamentals so challenging!

 

[Stylee Mousse]

None of my stage rigs ever sounded less than stellar with the low E. Why? They were all 215 cabs, and well designed ones. Criteria: sound strong and tight, don’t flood the stage with too much bass. Lock in with a good kick and bandwidth well with other instruments.

a bit of “there is no replacement for displacement”.