Cleanest way is to use bigger driver so that you dont have to raise anything with EQ. If you have to raise, goal is somewhat flat response and measurements tell if it is not and boost is applied accordingly, Equalization.
Boosting small driver with EQ will make it sound louder, but worse, because it will now work closer to its limits, distortion increases. Substituting small driver with bigger one will raise the bass and make it sound better and louder, bogger driver does bot work on its limits, less distortion. Using bigger driver is much better option than boosting small speaker with EQ if you wish good sound.
You are on rigth track, I guess, with question that when response drops at some freqency. Instead of boosting with EQ or switching to a bigger driver you could instead just crossover to another driver driver whose response drops much lower and is capable of extending the whole system low frequency response. Crossover to a subwoofer. Big subwoofers are capable going low and loud, small subwoofers are marketed so but they really do not deliver.
Why? already wrote this earlier. because of ever longer wavelenght requires more volume displacement to get excited to same SPL as shorter wavelenghts. Tweeters are same size as high frequency wavelenght. 3" driver is about size of 4.5kHz wavelenght and while it outputs some bass it would need to make huge excursion for enough volume displacement to make much 40Hz, which has longer wavelength than most listening rooms. Wavelenght is physical size of sound, the very thing we listen to. Wavelength is in key role to any acoustic phenomenon, including loudspeakers.
Again, if the speaker needs to be small as planned then that it is, the bass response and SPL capability is just that, small. Just build it and hear if there is enough. Boost with DSP. If it doesnt quite convince then build bigger speakers.
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LOL, NO!
Many people are happy to help you on a 'learning journey' but are not happy to solve for you. At times that can be frustrating as you just want a solution and you feel lost, but people do not want to work for free, they want to help you enjoy the same thing they enjoy.
If you came to this forum expecting free work, you are an ***-hat.
He has been told this many times now by you, by me, and by others as well. But he doesn't like the answer.
He still wants to get 50 Hz at 80 db out of a 3-inch driver even though it can't be done. At least not without excessive distortion that will ruin the fidelity of the music.
And since he doesn't like the answers he is getting here, he thinks the people over in the amplifier forum will help him. As though it's an amplifier issue and not a speaker matter. His unwillingness to accept the facts is starting to get tiresome. I say let him go to the amp people and have them deal with it.
Ok, I think it's time to wrap this up, I think more or less I know where to go from here, people that give advice based on measurements have no idea what they are talking about. I put zero stock into advice that is based on graphs or number crunching, I put 100% stock into someone that owned ten pairs of small speakers and built another 10 with different drivers and different amps, crossovers… in similar size to mine.
I know that color in sound is based on distortion; I know there is also something called saturation, which is somewhat a form of distortion. When digital came out it wasn't as smooth as it is today, so many engineers would record to 2" tape because it added saturation and warmth adn more head room, then they ported it over via A/D to process it further in digital form.
Color comes from the amp and possibly crossover components. I owned two extremes, one is Avalon U5, very clean no color, one is Focusrite ISA 115, the 115 is noisy with lot of hiss, but it's the fattest, punchiest, warmest pre-amp I ever heard. It's tattooed in my head, that sound was priceless.
For listening to it all day you'll get tired, but to run something thru it for a recording or for 30-minute punch in your face with fatness, it was a blast to hear it.
Rupert Neve put that unit together in short time frame, he did not obsess himself on too much measuring, because you can spend 8 hours experimenting with components or 4 hours and then 4 hours of measuring. In the end 99% of all good inventions are based on luck, you throw something at the wall and it sticks. The ones that spend more time throwing **** at the wall get there faster vs. over measuring things.
The guys that own these ISA 115 units recapped them with newer caps to keep the noise down and they never resell them, because they can’t find anything from new stuff that has that warm fat punchy sound.
So all this talk about it won't play at 50hz or it will, it will distort or not. My current cheap speakers play all the frequencies that I need in my head not on paper, it doesn’t play clean but with the tone controls they play it all, low end and loud enough. So there is definite color added here via that cheap Class A/B amp and that tone control. I call it saturation with some level of mild distortion. Not the distortion that you guys describe or get paranoid about.
You guys can talk all about math and graphs it will distort at this frequency or at that db level…........I listen with my ears not my eyes, Rupert Neve designed gear with his ears not his eyes.
There was sound advice here by people that actually made things, but it was overwhelmed by a majority of people that did not make anything related to my project and based their answers relying on too many hours spend on graphs and simulations. Simulations and number crunching have their place but not at 50/50 hours spend ratio.
Lets end on that note, and I move on to my other questions related to color in the sound by starting new topics.
Cheers.
I know that color in sound is based on distortion; I know there is also something called saturation, which is somewhat a form of distortion. When digital came out it wasn't as smooth as it is today, so many engineers would record to 2" tape because it added saturation and warmth adn more head room, then they ported it over via A/D to process it further in digital form.
Color comes from the amp and possibly crossover components. I owned two extremes, one is Avalon U5, very clean no color, one is Focusrite ISA 115, the 115 is noisy with lot of hiss, but it's the fattest, punchiest, warmest pre-amp I ever heard. It's tattooed in my head, that sound was priceless.
For listening to it all day you'll get tired, but to run something thru it for a recording or for 30-minute punch in your face with fatness, it was a blast to hear it.
Rupert Neve put that unit together in short time frame, he did not obsess himself on too much measuring, because you can spend 8 hours experimenting with components or 4 hours and then 4 hours of measuring. In the end 99% of all good inventions are based on luck, you throw something at the wall and it sticks. The ones that spend more time throwing **** at the wall get there faster vs. over measuring things.
The guys that own these ISA 115 units recapped them with newer caps to keep the noise down and they never resell them, because they can’t find anything from new stuff that has that warm fat punchy sound.
So all this talk about it won't play at 50hz or it will, it will distort or not. My current cheap speakers play all the frequencies that I need in my head not on paper, it doesn’t play clean but with the tone controls they play it all, low end and loud enough. So there is definite color added here via that cheap Class A/B amp and that tone control. I call it saturation with some level of mild distortion. Not the distortion that you guys describe or get paranoid about.
You guys can talk all about math and graphs it will distort at this frequency or at that db level…........I listen with my ears not my eyes, Rupert Neve designed gear with his ears not his eyes.
There was sound advice here by people that actually made things, but it was overwhelmed by a majority of people that did not make anything related to my project and based their answers relying on too many hours spend on graphs and simulations. Simulations and number crunching have their place but not at 50/50 hours spend ratio.
Lets end on that note, and I move on to my other questions related to color in the sound by starting new topics.
Cheers.
Have been reading this thread with interest and trying to stay out, but can't any more. I have been through a similar process, and I don't think there is any thing said so far I have not thought about already. A while ago I was given a request by SWMBO to build a pair of speakers to fit "there", she pointing at a space about 4inches wide for each side. Ok, that is a challenge and I will need to think about it says I. Out of earshot it was holy crap, how do I get any sort of bass from that narrow space. Ask SWMBO what she has in mind in terms of shape. Small was the answer, but tall and slim was acceptable. 4inches wide pretty much mandates a 3inch driver after taking into account the thickness of the cabinet sides and driver clearances. What are the characteristics of 3inch drivers - small Sd, and thus small displacement, inefficient, and small power handling. Equalization is impractical because you run out of Xmax and or fry the voice coil (been there) before you get any decent listening volume. So how to get 50Hz passive from a small driver. Answer, Transmission Line cabinet, 50hz is possible. Looked around for a 3inch with big Xmax, came across the Dayton D91, modelled it and yep 50hz in a small MLTL is possible in a 4inch space. 2 (double the displacement) with a tweeter should go down to 50hz, but only just barely, and then it drops like a stone. Sat on that idea for a while, and almost bought the drivers, but heck, a 3in driver is going to have very high distortion 50-100hz leading to "wooly" sounding bass. Unacceptable. Ask SWMBO about a sub, answer NO. Thinking cap back on. Came up with this - 3inch driver and tweeter on the front and a 5inch driver on the side in a MLTL cabinet. Still small, but would be much better sounding, and will easily reach down to 50hz. Is now a 3way so crossover is much more complicated but so long as the lower crossover is below the baffle step, then a side mounted driver should be ok. If the 3inch is full range and has a smooth treble then maybe a tweeter is not necessary. There are many possibilities, and can use more than one 3inch to match impedances and/or improve efficiency, but most likely will need a tweeter for best results. So, many hours later, modelling MLTL with various drivers I have come up with a design that should sound more than just ok. I am on the verge of ordering the drivers. However, apparently driver suggestions are not wanted here, so I shall remain quiet on the details. So it is possible, but not just with one 3inch driver. That requires unacceptable compromises in performance, or at least it is completely unacceptable to me for playing music. If you are willing to accept what are really quite severe compromises in performance, then fine, go ahead and try one 3inch and see if you can stand the limitations. Personally, I can't. Oh, but the way I have been fiddling around with small drivers in MLTL cabinets for many years.
Mmm, looks like he got in before I finished typing. Was quite rude to some. If you don't listen to the advice of others because they are telling you something you don't want to hear, then you won't learn anything. Some have strayed away from the topic a bit, but overall has been mostly very good advice.
Good luck.
When I need to cut something, I measure the length twice. When I need to make a speaker, I measure the spl's hundreds of times. My ears have the final say but I measure to confirm and contrast. I don't trust my memory for more than a few seconds for comparing sounds.
I hope you don't take people's suggestions as a slam against your experience or what you hear. I think the best result comes from understanding how the human ear works and from measuring with an objective tool.
A nice read:
https://www.ncbi.nlm.nih.gov/books/NBK207834/
Why ask for help if you already know better than everyone on here?
You need to think the process through, imagine late Rupert was on the forum and told you exactly what to build. Would it look like your speaker? no. Ok, you tell him you want to build this instead of that and he would say "ok, then put these drivers and electronics in instead, it might work just fine" but you'd say "no, I want it my way."
Now if Rupert was patient and generous enough to provide free consultation help to make Your design sound somewhat nice, he would ask measurements because there is no other way to continue with the terms and conditions laid out. I really hope you find your way but the attitude is holding you back currently.
Every industry has their Ruperts, experts, and they are most likely working with companies that prohibit sharing all info they would perhaps like to share personally as they are nice people. Fortunately we have some who have, like Tom Danley.
Now imagine there is Rupert in small loudspeaker industry, who might he be and who is he working for, where and what are the products? I have no idea who he or she would be but I suspect he is fully employed at some big tech company like Harmon, or perhaps Amazon or even Apple, becaise they need experts and pay the expert service. Perhaps he has his own company. There is no way you or we can beat their products in the same game as they are mass produced. Hence, buying ready made product is best bet for good sound in the small speaker realm as it is the most sold format in the market, very competitive field. Or just build what you want!
This is such a funny statement. I started this ‘hobby’ long time before measurement gear was affordable to anyone outside an acoustics lab. Listened and listened for years. Until I got hand on the means to really measure what I was hearing. And discovered literally everything on speakers is about combining measuring and interpreting with listening. Only the last decade and a half or so we are able to ‘predict‘ listening results. Why? By measuring even better and interpreting further.
My 2ct? Anyone who makes a statement such as above either has no clue or is plainly trying to annoy a lot of us here.
I have some suspicions that the person who started this thread was a troll from the beginning and annoying us was really the goal. It's hard to prove it, but reading some of his comments it certainly seems like that could be case.
A lot of his posts start off with ranting about things that have nothing to do whatsoever with the subject at hand. Pretty consistent with troll like behavior.
By technical meaning when most say it responds to 50Hz, it means flat to 50Hz all the way from 20kHz or -3dB. That would be what your ATC does. What you hear is the speaker starts to roll off at 200Hz and at 50 Hz it is 20dB down down from flat. Which means it technically responds 50Hz but 20 db softer than what it should be. You will still hear it of course but much softer than what it should have been. So in which case, put a 3" speaker in your sealed cabinet and it should achieve that.
Yeah, I've always followed the pioneer's way of sizing based on low Xmax, so for 3" it takes a min. (8) 3" to do it at my < ~1 mm reference for < ~6" drivers.