Debunking Audio Myths, Misunderstandings and Misnomers: Part One

[@TheRattleSnake3145]

You are thinking about it the wrong way. A 12 inch sub in the correct box will go lower and be louder than a 6 inch sub in the correct box. Putting the 6 inch sub in the correct box and the 12v inch sub in the wrong box is not a fair comparison. The same thing goes with your example of the tower speakers, just shoving another driver in the same box is going to present the incorrect box size to each driver. You should have compared correct setup to correct setup, its not suprising that the incorrect setup doesnt work as well.

[@welderfixer]

Another good presentation - keep them coming. However, After 40 years I'm finally figuring out that no matter how much is foolishly spent on speakers you will never be satisfied with them.

[@AxiomHomeTheaters]

Thank you! I got off the merry-go-round of equipment swapping many years ago and tend to live with components, including speakers, for a long time. I agree it’s tough to ever be completely satisfied!

[@welderfixer]

@@AxiomHomeTheaters There's more to life than spending entire paychecks pursuing gratification of one kind or another. Some of the happiest people on earth have very few possessions.

[@AxiomHomeTheaters]

Very true, and yet many find their hobbies bring them great joy & satisfaction🎵.

[@brydon10]

It's really just all about the music. But unfortunately for us "audiophiles" we're only happy if we're unhappy about something in our system!

[@Sam-ch9mn]

You could argue that ignorance is bliss. If you don’t know that you could get far better sound quality out of your system and accept what you have as adequate, life is calmer. That’s why these videos are both gratifying and slightly frustrating. I now realise there are things I could have done that would have improved the kit I have - and have had for 20+ years. That’s irritating. However, the explanations in these basic videos are so helpful I’ve already made some cost-free adjustments that have improved the sound quality. You just don’t know what you don’t know. Thanks for all the sage advice and info. Now a subscriber and looking forward to more.

[@gerritgovaerts8443]

A bigger woofer will definitely be able to play louder if it has more air displacement (Sd x Xmax) . Bigger woofers have more Sd by definition and on average also more Xmax.

[@gerritgovaerts8443]

A woofer that is not in an enclosure (just mounted on a baffle) is a dipole and it definitely has bass , very good bass even . The acoustic null will only appear at 90 degrees . Dispersion is like a figure of 8 : plenty of bass in front of the driver and plenty at the rear , none at right angles .

[@status101-danielho6]

Very informative. I owned a pair of Nuance 330 tower loudspeakers, and I even though it had a tweeter and a 5.5" woofer, it definite went low. I didn't even bother with a subwoofer, I never found a crossover blend that went lower in the various rooms it was on. I'd like to see perhaps a future audio myth about codec bit rates and digital audio, and at what point it's effectively transparent. On one side are audio engineers like Ken Rockwell who say uncompressed 16 bit/48kHz of CD is enough to capture music, and on the other side is Bob Stuart of Meridian saying that you need high resolution audio bitrates and lossless to capture everything.

[@AxiomHomeTheaters]

That’s a great topic…although I can’t say they high resolution audio is necessarily a myth, it would be interesting to discuss. Thanks for a great idea, and for watching.

[@xxr99]

Your videos are great .l watch them all . learned a lot about my home theater keep itt up

[@AxiomHomeTheaters]

Glad the videos are helpful, thank you for commenting and for watching.

[@richdevries5178]

Andrew articulates his points so well. Clear and easy to understand.

[@AxiomHomeTheaters]

Glad to know it's clear, it's a hard balance between too technical and too dumbed down, thank you!

[@basscannon762]

Great presentation. I’ll try to articulate this best through text. From what I understand is, yes you can get amazing frequency response and low frequency extension from a 6.5” for example. What I didn’t hear was about pressurizing a room or subsonic frequencies. These are bass head problems trying to reproduce 20hz at 100s of dbs so it might not apply here to audiophiles. Thought?

[@AxiomHomeTheaters]

Sound reinforcement is a different problem to tackle, however I've experienced many designs with a couple of 8" woofers that can easily energize a room at 20 Hz. Bigger doesn't necessarily mean lower.

[@n.o.b.s.8458]

To add some color here, the following is true: Large drivers do not necessarily produce more bass. Small drivers in a large cabinet (assuming correct tuning and good driver quality) can produce great bass. If you're looking for low bass that's also loud with plenty of headroom, you almost certainly need a larger driver. If you look at the speakers used in live music and movie theatre application, they are huge, with huge woofers. However, that's because they're designed to hit insane volume levels and fill an enormous space with good bass. For HOME applications, you do not need a massive woofer in your speakers. It's also almost certainly not worth getting floor standing speakers to try and get more bass, partly because a subwoofer should be taking care of the very low frequencies anyways.

[@ColinHeizer]

A big heavy cone is a good thing on a subwoofer that needs hit lows.

[@JayThomasofficial]

Ty for this . I am setting up my speakers now ( Mackie 10 “) I have a stupid question. Is there anything I shouldn’t have near the them ( I.e. magnets , or maybe too many plugs , my focus right Safire 6 , or like my laptop?) etc stupid questions sorry I feel silly thanks for not judging and any info thanks ( ps or maybe a website or KZbin channel etc that explains a lot of these myths ) thanks

[@kennethcohagen3539]

Great explanation! I’ve been aware of this for a long time, but it’s always good to brush up a bit and to find someone who’s willing to help the younger generation? It’s a good thing! Maybe next you can demonstrate the difference between boom and accurate low frequencies, reproduced with enough detail to play anything from classical to Rock. This is the total opposite of the typical boom box car subwoofers.

[@AxiomHomeTheaters]

Thanks…I’ll see what I can come up with for a future video!

[@sevenlayers7L]

I feel as though this was the perfect explanation as to why I fell for my M40ti’s.. and in the event where I am feeling the need for just abit more power.. I just connect my M3ti’s in series, and run the M40’s & M3ti’s as a 4 ohm load.. and do Have got to say, I was pleasantly surprised to say the least. Definitely no M80/M100’s replacements, but a surprisingly close runner up.. -though, I do realllly want to try this same setup but with M22’s instead of the M3’s - thinking that’ll be the sweet spot right there - almost a M60 - kinda :)

[@AxiomHomeTheaters]

Interesting…I think you meant to say parallel connected, not series. 😉

[@bunjidogg]

So you are saying that a well designed box with 12" woofer will not play below 40 better than a well designed 6 1/2" ?

[@rudolfhuijs4526]

Hi there Andrew, have one question: does ported or non-ported speakers have any influence on low frequency response, let's say drivers of 5 1/4" or 6 1/2" in a floor standing configuration? Thanks.

[@AxiomHomeTheaters]

Hi Rudolf. Yes, ported vs. non-ported systems will behave differently in terms of bass roll-off and many times a ported system can offer more extended bass. However, it’s not necessarily always the case because it depends on the driver parameters, cabinet size, and the port tuning interacting with one another. Thanks for watching.

[@rudolfhuijs4526]

Axiom Audio Great! Thanks.

[@anthonycallahan4832]

There’s a lot of inexpensive used speakers - I have a mix of speakers- woofers 15 12 and 8s - sounds great to me - was thinking best of both worlds

[@AxiomHomeTheaters]

Hey, if you have the space it’s great to switch it up from time to time.

[@alexsuarez1843]

Great video, keep up the good work!

[@zzxxyy22]

How does one "pair" power of amp to speaker RMS ..not good to push the amp to its limits..and vise versa

[@AxiomHomeTheaters]

That’s a very tough question as it’s not a simple matter of looking at speaker power handling and impedance. In most cases I recommend speaking to the speaker manufacturer or dealer to discuss what amp you want to use or are thinking of purchasing to see if it will be a good match. Thanks for your question, and for watching.

[@NackDSP]

No, the bass maximum SPL is completely determined by the displacement volume. That's the linear travel multiplied by the cone area, Displacement = Xmax * S. Nothing else matters, not the box size or cone diameter, it's the total displacement. So long throw small woofer can have the same displacement as a short throw large woofer. You quickly find that the price of a woofer tracks with the Xmax and displacement. Cheap woofers have a small Xmax and expensive woofers have a large Xmax.

[@SdeGat]

Very interesting educational video Andrew. Thanks. I have a question though; why are there (still) so many large woofers out there? Like in the "sound reinforcement" business for example, why don't they have smaller woofers in better designed cabinets? (which would be smaller/lighter) Or is it that smaller woofers would actually require larger cabinets for the same sound output? (making that business sticking to huge 18inch woofers in reasonably small cabinets?)

[@AxiomHomeTheaters]

The reason is mainly for high power handling and higher sound pressure levels that you will see in professional sound reinforcement systems. Many of those systems have very poor deep bass, but they don’t need it as this is usually handled by dedicated subwoofers. A bunch of small woofers would require large numbers to make up the same output capability. In most cases, speaker sensitivity is the predominant concern in sound reinforcement. Thanks for a great question, and for watching.

[@MrROTD]

I built two way towers with 6 small woofers, one powerful titanium tweeter and a 12 inch passive radiator on the side, its all configured like a line array at a concert best design I ever made sonically but its too expensive to be built in any numbers.

[@AxiomHomeTheaters]

Good quality, high-excursion smaller woofers can provide excellent performance if tuned and aligned correctly. It sounds like your design is a good example!

[@dwaynepiper3261]

Do high-excursion smaller woofers have more distortion from the voice coil movement? Can you elaborate on what tuned and aligned correctly means? what are the drawbacks of high excursion small drivers? I have a pair of 2 way Yamaha bookshelves with single 6.5-inch aluminum high excursion woofers in a sealed acoustic suspension box. They are rated down to 60hz but it does not say this is -3db so I suspect it's -10db. What surprises me is the high sensitivity of 90db and 8 ohm. My understanding is you can't have a small box, high efficiency, and low bass at the same time. I rarely see bookshelf speakers with this kind of specs although your bookshelves do have similar specs. I see a lot of speakers rated at 4ohm and 87db sensitivity which is more equivalent to 8ohm and 84db sensitivity.

[@mikemc330]

Good info. Thanks

[@josephfranzen5626]

I know my Mirage OM10’s have exponentially more usable low end output with their front and rear firing 6.5” woofer compared to a pair of Klipsch dual 8” woofer towers my friend has as measured by REW in the same room, using the same amplifier, source material and measurement equipment.

[@AxiomHomeTheaters]

Yes, it all depends on design and tuning. Sometimes the goal is to sacrifice bottom end extension for system efficiency.

[@joeindia1647]

Really? A 12'' woofer travel 5mm equals a 6'' woofer travel 20mm approximately. The effective volume is not the size of the cabinet, rather the air volume the woofer can move.

[@bhanuprakash3220]

Please suggest how to suggest tower package; for what size of room dimensions

[@AxiomHomeTheaters]

It really depends on the speakers. I would suggest speaking to the manufacturer about the models you’re considering. Thanks for watching.

[@stephenc2738]

I had an opportunity to compare two, well-designed Canadian loudspeakers through high-end, single-ended (Canadian) tube electronics in a very good listening environment. One was a Tower, multi bass woofer system, the other a two-way, stand-mounted speaker having a HF driver and a single 8" woofer. The two-way system's cabinet and crossover were designed using the National Research Council of Canada's anechoic facilities. The 2 way system's bass was deeper, more accurate and completely outclassed the Tower speaker system whose retail price was twice that of the stand-mounted system (including custom metal speaker stands).

[@AxiomHomeTheaters]

I have experienced this many times over the years. Good speaker design is more important than size, driver compliment, or anything else.

[@georgebartolo8856]

You use aluminium drivers. Would they tend to have a brighter presentation compared to say an paper or silk driver?

[@AxiomHomeTheaters]

No, this is a common misconception: A “soft” material will sound “softer” is not true. It’s really all down to driver design, control of cone or dome resonances, and using drivers within their linear ranges. One big benefit of aluminum cones on woofers and midranges is that the cones act as heat sinks, helping to dissipate heat from the voice coil. This makes a huge difference for power handling. Thanks for a great question, and thank you for watching.

[@georgebartolo8856]

@@AxiomHomeTheaters yes true . My speakers have soft dome tweeters but tend to be bright sounding.

[@trevornmartinmartin2756]

excellent

[@Obsfucation]

You don’t mention anything about radiation resistance of the woofer cone to the air. This is directly tied to the area of the cone and is why one of the T/S parameters is “Sd”; the area of the cone. At 4:45 you say that the idea that a larger woofer being more efficient “is total nonsense”. All things being equal in a given driver the larger cone will always be (because of physics and not your opinion) more efficient. Do your homework, sir.

[@AxiomHomeTheaters]

If you pull out a single Thiele-Small parameter like Sd and change it, and only look at the resulting change in reference efficiency (n0), I’d agree with you. Sd^2 is in the numerator of one of the standard equations for n0, so if you increase Sd, n0 will increase. However, this is not reality. Is the larger cone going to weigh more than a smaller one, if the same diaphragm material is used? Yes. Will Fs go down? Yes. Mms (Diaphragm mass including air-load), which has increased, is in the denominator of the n0 equation (actually Mms^2). So, is the increase in Sd larger than the increase in Mms? All things being equal assumes that we have not changed the motor in any way and hence BL has not changed. My point in the video was to caution against making generalizations. Can a larger driver be more efficient than a smaller one? Certainly, it can. I can make the larger driver with a thin, light paper cone and the smaller one with a heavier, multi-layer sandwich of aluminum honeycomb. But the opposite can also be true…

[@jjmatrix]

I generally like your presentations... a lot I might say - I could be biased though as I own many Axiom speakers, M80s, M3s, 2 centre channels, Q8 surrounds etc 😊. That being said, I sincerely do not believe this particular presentation to be entirely correct. I do understand that bigger MIGHT not necessarily mean lower, but that is perhaps only 1% of cases. Without getting into technical details, my subwoofer (12" drive, sealed and essentially a 16' cube that equals to approximately 4100 cubic inches) goes lower than my pair of M80s at about 6200 cubic inches AND ported. I also cannot avoid pointing out that "bigger is better" is the reason why you (Axiom Audio) are not manufacturing any 6.5" driver based subwoofers. Even your small EP-125 sub outperforms (strictly bass) the M80s by going lower and louder.

[@AxiomHomeTheaters]

In some cases you are absolutely correct, but it is not a tried and true rule. With subwoofers you can make even a small box with a small, high excursion driver, play very low with the help of EQ and lots of amplifier power. But when we’re speaking about passive systems without active EQ, a bigger woofer does not necessarily mean a lower bass cut-off.

[@jjmatrix]

@@AxiomHomeTheaters looks like we are on the same page. I should've been a little more specific... Absolutes are the "enemy" so to speak, as both opinions have merit and are true to a degree.

[@AxiomHomeTheaters]

@@jjmatrix Absolutely!

[@westelaudio943]

Larger woofers are *less* efficient - sorry, what? That is obviously, as a general statement, *not* true. If you compare speaker drivers of similar build, say, in the same model series, the larger ones will always be more efficient nominally, and even more in the low end. A larger cone just does a far better job at coupling the coil movement to the surrounding air and also provides lower Fs. Additionally a larger cone also allows you to use a stiffer suspension while maintaining a relatively low Fs, which in turn means a narrower air gap can be used, thus: higher sensitivity (power needed to overcome a stiff suspension isn't actually lost - it gets released again when the cone bounces back to the center - it's apparent power rather than real power). As someone representing a major audio company I'm sure you must be aware of those simple facts. But it seems like you are creating myths rather than busting them...

[@AxiomHomeTheaters]

While the specific cases you are describing are absolutely correct, I would be careful in generalizing. I can make a 12 inch woofer with a light cone that will have an Fs much higher than a 6 inch woofer might. In an apples to apples comparison with identical materials the cone of a larger woofer will weigh significantly more than a smaller woofer. This will then require a beefier motor to overcome the efficiency loss because of the higher cone mass. So, please understand the video was meant to stamp out absolutes where many believe a bigger woofer will always give you more and lower bass output.

[@westelaudio943]

@@AxiomHomeTheaters As an absolute statement, it's false, that's true. As a general tendency, it is correct though - and you made it sound like the opposite is the case. I think a better way to simplify the situation is: High sensitivity, low Fs (Fc), compact size - pick _only_ two. Also, I think the gain from a bigger surface area actually overcomes the losses from a higher mass to some extent - several manufacturers use the exact same magnet and coil structure for, say, their 6.5 and 8" woofers, as well as the same cone material, yet still the 8" will come out as slightly more efficient and significantly more low end rich. Further, fitting a larger motor to a larger driver is not really a problem - it's something most manufacturers do anyways.

[@plcamp1]

In open baffle, size does matter on woofers. Displacement demand of open baffle force large area bass drivers.

[@AxiomHomeTheaters]

That’s true, but it’s mainly to get any semblance of sensitivity out of those systems at low frequencies.

[@IvanToman]

You seem to forget that woofer SPL is limited by it's xmax, and that to maintain particular SPL level, for every half of frequency, cone excursion goes 4 times larger. The product of cone area and travel distance gives the volume of air displaced and thus, defines SPL. And you cannot make infinite cone travel, and long throw woofers have disadvantages, like reduced EM gradient, etc. Yes, even tweeter can easy play 20 Hz or lower. How loud is completely different question. For the second "myth", that multiple woofers system will have higher resonant frequency than single woofer system - all I will say is that if you plan to use multiple woofers you must design proper enclosure for that number, you won't put them into enclosure designed of single driver, ha?

[@AxiomHomeTheaters]

No, I have not forgotten. But just as I can have high and low Fs woofers of any size, I can also build an 8” woofer with far higher excursion, and hence maximum SPL, than a larger diameter woofer with a thin pleated surround. And you are correct, any good designer will put the driver configuration they’ve planned or been told to use in an appropriately sized cabinet, tuned correctly. However, I’ve seen many variations on the market where one model in a line has two woofers, and another slightly taller version with three. I can guarantee you that the volume is not 50% larger for that 3-woofer version.

[@IvanToman]

Well ok, but you must agree that there is a limit to how large cone excursion can in real world be. There are long throw and longer throw woofers, but there is just physical limit how much you can increase that. And when you reach that practical limit, you don't have a choice anymore, the only variable that can increase loudness at low frequency will be increasing cone area.