Mixing driver sizes

[seamonkey]

Usually when someone says "Show me the science" they have already positioned themselves. It's been that way for centuries.

One thing for sure, very few cab makers give you enough knowledge about their cabinets to let you successfully make your own stack.
There's more information on the side of a tire that there is for many bass cabinets.

Mix all you want, you could luck out. You could end up with something that works, or you could end up with something that isn't going to measure "flat" but is just the degraded sound you want. I've never said that cabinets have to be "flat" - they just have to be measured so I know what they can do. I'm not willing to try every cabinet out there, just want some honest measurements. If you have a good sounding stack, take a plot with a smartphone RTA - when you look for a new stack, see how well it matches. Usually what is "Familiar" will sound best, you're than likely going to like a clone of what you have now, except more bass!

 

[BurningSkies]

Right, but how come the detractors seem to imply ALWAYS in their arguments? There is no ALWAYS when it comes to personal tastes, and other people's preferences aren't necessarily wrong, or bad, or stupid, or whatever negative word used to describe their preference.

TB always works in always, except when it's a never.

Never scoop your mids, always attenuate, never boost, always send your DI pre-EQ, always set your amp 'flat'. To the same extent that everyone thinks their answer is the answer to every question.

I still believe the quickest shortcut to the least amount of speaker problems is to match your cabs. When it comes to powering them successfully, when it comes to them being balanced with each other and in terms of them not fighting against each other. The game of random mixy-matchy leads to random results. Unless the answer to many threads is 'mix whatever for a decade or so until you find something that works out'...which is what many of us did for along time. Those results can be awesome, but in the meantime, someone's spending lots of money and lots of effort to get from point a to point b.

 

[agedhorse]

I never mentioned anything about flat, nor did I suggest using an RTA.

Rather than flat, how about the industry change to "target voicing", which is more representative of what the design process is based upon. Every manufacturer struggles to develop and maintain a family of target voicings for their various product lines. These may be flat, highly colored, or somewhere in between. there is no right or wrong, just a preference to a particular target voicing.

For what we are discussing, an RTA is not the appropriate tool as it will give you only a portion of the data (and not necessarily the important portion). It's also important to understand the phase response, the summed acoustical response and the boundery interactions (that can affect some configurations more than others) because audio has both amplitude and time components to every response. Eliminate one from the analysis and it's like flying blind because you don't know how say the amplitude data may be being skewed by the time data. Both parts are necessary. This is what I mean by understanding and applying the complete data set to any argument. This also means understanding what the data means, and not arguing that the phase response is like a sawtooth when the sawtooth pattern is actually a measurement artifact and not at all like that if the scale was continuous in the comparisons.

Years ago on this forum, I received a bunch of crap for my position on speaker non-linearity, measurement of power limits and the effects of power compression, again because of poorly informed science oriented individuals (in some cases the usual suspects). In fact, the data and methodologies that I developed (and we also used at GB) have become one of the accepted standards based on non-destructive ways to measure non-linearities. It's one of the ways for determining Xmax on an electro-acoustic basis by looking at the onset of the acoustic signal trending away from the 1:1 transfer function under burst operation. This mostly eliminates the thermal component from the "power compression" calculation yielding the electro-mechanical root causes. This is one of the Xmax factors measured with Klippel. Now I didn't come up with this on my own, the (engineering side of the) industry did over a period of years, probably the earliest commercial approach using this method was the IASYS analysis system, but thyere were other less well known FFT approaches as well. As crazy as my "opinion" was called at the time, it was based on science and engineering that was just not understood by those arguing their closed minded opoinions, it has become one of the gold standards of professional, engineering based non-destructive loudspeaker analysis.

 

[agedhorse]

The game of random mixy-matchy leads to random results.

I do agree that "random mixy-matchy" is probably going to be less successful overall than using identical speakers, and yes, on scientific terms too

 

[Downunderwonder]

And I am going to point out a factual error that Bill constantly talks about, "that a 410 and 115 have essentially the same frequency response" as either uninformed, misunderstood, or based on some agenda that i am not aware of.

And I am going to point out a factual error that Bill constantly talks about, "that a 410 and 115 have essentially the same frequency response" as either uninformed, misunderstood, or based on some agenda that i am not aware of.

Fair suck of the sav! Clearly Bill was referring to using full range cabs (essentially the same) in a frequency split biamped system. Quoting out of context you'd think he was some raving lunatic.

 

[BurningSkies]

I do agree that "random mixy-matchy" is probably going to be less successful overall than using identical speakers, and yes, on scientific terms too

Add to that the common mythology that so many musicians live within and you really get a mess. Need more lows? Get a 15. What 15? Well, 95% of the players out there will tell you that all 15's are lower. Recently a pro on TB stated that there are no situations where anyone needs more than a 410. Oh? Really. I guess anyone who uses several of them, or an 810 or any other rig that has more potential volume than a 410 (which 410? again, no specifics...just 410's in general, I guess...they're all the same, right?), is just being ridiculous. Except that there are plenty of us out there that use 'more' and need more on a regular basis. Remember, the vast bulk of musicians still think that 12's are for guitarists and that 10's are always tight and punchy and fast with no deep lows.

 

[KevInDaBassment]

From what I read on here, if something is engineered and designed to be mixed, that's a completely different story than just random mix-n-match. You might even get a good sound mixing a 2x10s and 1x15 cab from the same company, but two totally different ones from different manufacturers would make me skeptical. If I'm adding more cab, it's typically for power handling and volume. You'll get a bigger spike in volume by adding more cab than more amp wattage.

Maybe Ampeg or Markbass anticipates users mixing cabs and they design around that, but maybe they don't. Offering different cab sizes may be for tonal issues, but volume and portability are definitely big factors as well. I've had the best results with matching cabs, YMMV. I do appreciate the science giving me food for thought before buying cabs.

 

[Coolhandjjl]

And I am going to point out a factual error that Bill constantly talks about, "that a 410 and 115 have essentially the same frequency response" as either uninformed, misunderstood, ......

I read that linked thread, and reading between the lines, I walked away with this from Bill: both cabs are designed as stand alone bass cabs. Whether one is 40Hz~2000Hz, and the other is 60Hz~3000Hz is pretty academic. If one wanted to bi-amp, use the 15" up to 800Hz perhaps (we don't really know if that's a good point without any data on the driver but let's assume it's a good point anyway), and use the 4x10 for 800Hz and up, it would be a waste of a 4x10. One 6" driver designed as a midrange driver mounted in an appropriate enclosure would do the job, and sound better than a 4x10 throttled back in both frequency and wattage.

 

[Rick James]

And I am going to point out a factual error that Bill constantly talks about, "that a 410 and 115 have essentially the same frequency response" as either uninformed, misunderstood, or based on some agenda that i am not aware of.

You could test that by looking at the frequency response charts that every company prominently displays for all of their cabs.

If one wanted to bi-amp, use the 15" up to 800Hz perhaps (we don't really know if that's a good point without any data on the driver but let's assume it's a good point anyway), and use the 4x10 for 800Hz and up, it would be a waste of a 4x10. One 6" driver designed as a midrange driver mounted in an appropriate enclosure would do the job, and sound better than a 4x10 throttled back in both frequency and wattage.

That's what BFM Omnis do. So do fearful and Baer.

 

[friendlybass]

I'm definitely in the no science camp, but these papers are super cool and totally explain why my mixed driver setups sound awesome, and I happened on them accidentally! also makes me appreciate the engineering that went into my mixed driver cab, an ampeg 1528, cause it really kicks arse.

 

[Rich Terry]

Not again!!

What ever you think sounds good and works for you.

 

[Mr Gaston]

Usually when someone says "Show me the science" they have already positioned themselves. It's been that way for centuries.

Yeah, I already had a position but probably not the one you think. I've read enough TB to know that it's better not to mix driver sizes. I didn't doubt the validity. I just wanted the science. The Mixing cabinets and phase response thread was the type of thing I was looking for.

Now I can sleep at night.

 

[Munjibunga]

I may have mentioned before that I had an Eden D210XLT/D115XLT stack with my WT800 and never liked the sound AND my breath smelled like freshly cut grass. Now that I've gone exclusively to single-size drivers my sound is superb and my breath smells like cantaloupe. (My feet have always smelled like French toast.)

 

[strictlybass_ic]

There is a lot of science to this and i don't want to discredit or downplay that. But, the thing that jumps out as obvious to me and I think should be apparent to the "trust your ears" group is EQ. Different speakers generally will need a bit different EQ to get the sound you want from them. If you are using numerous copies of the same speaker then you don't need to worry about EQ changes. The response curve you're working with is the same for every speaker in your stack. But, if you use a 210, a 115, and sometimes both then (in theory) each different option requires you to adjust your EQ to get back to your "baseline" tone. That's the biggest selling point for me with all the same drivers. If I play through my 210 and then hook up another 210 it "sounds" the same, just louder. If I stack the two vertically (in line) then I reduce a lot of beaming, comb blah blah blah as well.

 

[Pimmsley]

I understand the science behind the principal not to use mixed driver cabs, but I have two current gigging rigs my older Hartke 210XL on top of a 115XL and an Aggie 2x 112DBNT's... I can honestly say that both sets give me what I want in terms of tonal goals and sound equally excellent in varied gigging situations, on stage and in the room. Having said that, I'm willing to concede that less optimal results could occur with other mixed cab arrangements

 

[chadds]

Right, but how come the detractors seem to imply ALWAYS in their arguments? There is no ALWAYS when it comes to personal tastes, and other people's preferences aren't necessarily wrong, or bad, or stupid, or whatever negative word used to describe their preference.

There's no "always" in science either. (Cue British accent) There's always something working on the effect causing another effect...

 

[Downunderwonder]

There's no "always" in science either. (Cue British accent) There's always something working on the effect causing another effect...

Au contraire. EVERY time I deadlift my 1x15 I am reminded that gravity ALWAYS sucks harder on it than the 2x10.

 

[agedhorse]

Au contraire. EVERY time I deadlift my 1x15 I am reminded that gravity ALWAYS sucks harder on it than the 2x10.

So the engineer in me might suggest a lighter (more gravity resisting) 1 x 15

 

[JeromeH]

I had just posted this before I saw this thread!
I'm trying to build a "stack" on a "low budget" saw a Fender 2-8 cab in the classifieds here. Could this work or is it just stupid? I have a Hartke 7000 head on it's way to me 350 watts at 4 ohms x 2. I currently own a Genz Benz 115 combo ( could just use it as an 8 ohm 115 cab) & an SWR workingman's 210 (also 8 ohms) Would adding the 2-8's and another 210 (both 8 ohm) just be crazy??? No I won't be buying an "Ambelic" bass anytime soon!!! Looking to "low ball" the whole set-up!! (By necessity not choice!!) In this particular case the word "dumb-ass"might be accurate!!

 

[davy4575]

In reading this, I really appreciate agedhorse's take on this and explanations. It puts it in a context I can understand. I dont have a dog in the fight at all, never saw a need to have a 15 or anything like that, was never against it either though. Just purely ambivalent. I do appreciate seeing myths debunked and seeing some accurate data explained. I guess I wonder why people do the mixed sizes if you do. Also, why does it sound to a lot of us that the 115 is lower. I totally understand the science that its not necessarily, but my ears (preconceived visual notions?) tell me it is frequently lower sounding. Help. thanks.