Why My DIY Speakers Sound Bad / Measuring With REW and UMIK-1
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- Опубліковано 3 гру 2020
- What I mean when I say there will be no major builds on this channel is that I'll be posting those on my main channel, where I do full project build videos. When I build a new set of speakers, that full build video will be on my main channel.
On here, I want to concentrate more on the technical, much like I do in this video. So I'll be going through details that won't be in a build video, or prototyping and testing.
Like I said at the beginning of this video, I'm not an expert but I do have a fairly solid background in designing and building speakers. I was heavy into this for several years more than 10 years ago and have forgotten a lot of what I learned at that time. I'll be working to get that back and learn more, but I will make mistakes along the way. So keep that in mind when you watch.
Regarding the tweeters in these speakers, that peaking is likely from a combination of the tweeter quality, poor crossover design and some diffraction. However I've found a replacement pair that are a better match for the woofer, and I'll be installing those with a newly designed crossover in an upcoming video.
Building the office speakers: • How To Make Bookshelf ...
Making the original crossover: • Making The Crossovers ...
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What I mean when I say there will be no major builds on this channel is that I'll be posting those on my main channel, where I do full project build videos. When I build a new set of speakers, that full build video will be on my main channel.
On here, I want to concentrate more on the technical, much like I do in this video. So I'll be going through details that won't be in a build video, or prototyping and testing.
Like I said at the beginning of this video, I'm not an expert but I do have a fairly solid background in designing and building speakers. I was heavy into this for several years more than 10 years ago and have forgotten a lot of what I learned at that time. I'll be working to get that back and learn more, but I will make mistakes along the way. So keep that in mind when you watch.
Regarding the tweeters in these speakers, that peaking is likely from a combination of the tweeter quality, poor crossover design and some diffraction. However I've found a replacement pair that are a better match for the woofer, and I'll be installing those with a newly designed crossover in an upcoming video.
Building the office speakers: ua-cam.com/video/GlBuJhMSmcI/v-deo.html
Making the original crossover: ua-cam.com/video/kO2faotm3sE/v-deo.html
Fascinating stuff John! As a fellow "speaker geek" I am delighted with your new direction!
I've been studying acoustics and speaker design since 1978, and STILL find it challenging!
So please keep up this speaker design, build and measuring content! I'm sure we'll all learn from it!
I’m glad you liked my logo idea! I like your rendition better. Clean and simple. I’m starting to build the 2”x 72” belt sander from the plans I won.
Very welcome and good luck with the grinder!
I am so glad you started this channel. Building speaker cabinets is how I got into woodworking.
I'm ready to learn with you! Fun times ahead
I'm still learning, when I saw the inductor weighing, ratio stuff, I kinda thought something was not right. But hell of a channel John. I love your videos. We'll keep learning together.
Love it. Been a professional audio fabricator since 89. Back in the day with Phoenix Gold amplifies we HAD to build the crossovers for drivers. It's a wonderful hobby and discipline. We always used a small anechoic chamber chamber to measure the driver's response. We didn't have fancy computer software back then;)
I didn't really understand any of those graphs but like your work and I love speakers so I am excited to see more videos. Thank you
i'm waiting for your next video. Thanks in advance :-) ! woodworking and speakers..... the best mix
I used to build drivers for a living, love the content
Oh man... This makes me miss the years I spent working in the rock and roll industry... We had lots of toys to analyze our concert rigs. So much fun to mess around with.
Great idea. Build different speaker cabinets, speaker stands, hifi racks/furniture, home cinema furniture/couchs.
From the camera angle it looks like you measured it with the mic aimed at the woofer, you should have measured it at the tweeter level and in between the woofer and tweeter, measure it with one of the driver polarity inverted to check for the null at the crossover point, and also add some baffle step compensation.
Speaking as a soundman, I approve this channel!
In order to properly splice nearfield to farfield gated response, you need to process the nearfield for cabinet diffraction. Your low frequencies will shelf down ~6dB and you will get some response modification based on the distance from the driver to the baffle edges. Also sometimes offsetting the tweeter to one side and rounding over the baffle edges will tweak the tweeter response to be smoother.
Awesome John
I'm gonna become such a nerd... I can feel the intrigue building within me. Let's go! I want to make my own high fidelity speakers too!! 🤓
If you don't have an anechoic chamber, wait for a windstill day and test your speakers outdoors. Test them on the lawn on a stand, not on concrete, wood, or anything that reflects.
It will give you a frequency response test without room interaction.
It doesn't work with cars and buses going by or planes flying around though, it has to be quiet :)
Love the logo.
Excellent name tbh. Cool logo as well
Would love to see you do a build of active speakers using MiniDSPs 2 channel plate amps with Icepower and doing all the xover design digitally.
I'm guessing it was the waveguide for the tweeter and perhaps the square box with no enough rounded edges. Did you ever replace the tweeter?
I would like to see testing of different types of speaker stands. I've never seen anything definitive regarding use of materials or shapes that influence sound.
Do you know how much the room modes and acoustics of the interference patterns generated due to the table in the room V.s how much is the actual response of the crossover? If you move that test to a closet full of clothes the response may look completely different.
Can you please do a comprehensive video on REW and the UMIK. Setup and calibration. Thanks
I had a bad woofer once, ended up finishing with her. I've no idea about speakers, but I'm all ears (and eyes) to learn
To have a good phase around cutoff frequencies, you must put the tweeter behind the woofer. Thank's to ARTA or HOLMIMPULSE, you can verify the phase linearity : CSD on ARTA is linear around the cutoff frequencies ; Phase on HOLMIMPULSE is linear too. You can invert polarities but the best choice is to push behind the tweeter and measure a lot of time.
Just found your channel John........very interesting. I also build speakers (sort of) I have a friend that does the custom crossover networks for me...........some can be really robust at about 5 pounds. Maybe we could swap speaker pics some time.
What is the free software you are using for analysis?
Excelente trabajo. Pero al medir en el taller la acústica de la sala afecta la medición.
Those spikes remind me of 🤔 John gets my vote 😉
Dumb question, John - why not do this in the garden ('yard') for a 'free field' response? I remember doing that years ago at university. We also had a calibrated protractor to measure off-axis response. Very impressed with the fit & finish and your mastering the software. Subscribed. It's going to be an interesting ride! All the best, Rob in Switzerland.
Wind, mostly. And inconvenience of setting it up - it has to be up high to clear reflections to get a measurement that goes down to a reasonably low frequency to make doing it outdoors worthwhile.
Doing it indoors is easier and the measurement can be used so that it doesn't include the reflections from the walls, floor and ceiling.
Subscribed:)
Interesting.
John, why don't you build a speaker with a full range driver and a port, there are some fantastic full range speakers out there like the tang bang W5-1611SAF that gets great reviews on parts express. it would be cool to see how it sounds in an enclosure. thanks
I got quite heavily into car speakers around 20 years ago. This is weirdly nostalgic for me. LUL
They didn't have speakers back then. Or cars
@@RendColt FeelsBadMan
Do you plan on experimenting with ribbon speakers at some point?
Anything's possible :)
Trying to do my part Brother!
How about forget the crossover entirely and use a stereo amp in each speaker to drive the cones separately. D-Class mosfet amps are dirt cheap, and technically it is a better solution as you can tweak it to get the crossover point and levels exact.
I had a high end audio system - and I really didn't like the harsh tweeter response at all. My wife purchased this cheap Sylvania audio system and it might not be as loud, but it made the music a 1000x more enjoyable then the high end system. You can hear the cymbals and snare drums so crisply on the cheaper system. It's a night and day difference when it comes to enjoying the music - I don't understand!
Mo money doesnt mean better sound. Maybe the new speakers work better with your room
What is the name of the software you used? I can’t make it out in the video.
REW - room equalization wizard.
I spaced my drivers too far apart too, but it's not noticable thankfully
Are you measuring the frequency response on the tweeter axis? At what distance?
Yes, at 1 meter. But having it at 1 meter is only important to measure the true spl.
@@IBuildIt Not really. SPL can be measured at any distance. Industry standard is 2.83v@1m. 1W is not an accurate representation as it assumes a fixed resistance of 8ohm.
Was just curious. For my measurements, I use 2-3x of the baffle width. This captures the baffle effect and use a 5ms gated response. In my room, this is accurate to 250hz. I set spl on the tweeter axis at 90db and measure all drivers from that point. This captures the acoustic offset of the woofer as well.
I don't think your loudspekaer is bad, but the room acoustics, the REW setup with sweeping sine in such a near-field measurement. We don't need a strong sine wave in a near field measurement as it merely brings unnecessary reflections.
To avoid reflexions from walls you can do groundplane measurements inside, or even better outside.
I do the opposite I make them to work in the room I'm going to use them in, who cares what they mignt sound like in someone else's house,now they don't work in your house, you guys have it all wrong, unless you are in the habit of bringing your system to other people's houses,build them to work in the room where thier going to reside
@@ericschulze5641 this makes a lot of sense
Wait a minute, did I hear right that you use weight of wire to calculate crossiver?I always thought that inductance of coil is calculated if you know wire diameter, interval between neighbour winds of wire in coil and inner diameter of coil, but not weight. I see you unwind factory made coil to wind new coil, but are you sure it's ok? Maybe your speakers sound bad because of improperly calculated and made crossover?
P.S.: When I design crossovers for speaker project, I usually calculate it's components values at least in two or three crossover calculators to avoid mistake. Crossover frequency is important too. In 3-way speakers I prefer 200 Hz and 4-5 kHz frequencies between woofer and mids and mids and tweeter. The trick is that bigger part of sound should come from one driver. So mids must be best part of your speaker, because we hear mids best of all. As for 2-way speakers, I prefer 3-3.5 kHz between woofer and tweeted, usually works fine. And tweeter is usually loaded by II or III order Butterworth. As for mids, it is usually I order Butterworth, but mid-range driver must have extremely linear frequency response between 100-5000 Hz at least. If it is so, result will be good.
How is this channel not called Heisz Fidelity?
The only reason why I am watching this is to learn how to use the umik and you cut out
"How Heisz Hears It." you may use this name with great abandon. :)
One of the most common issues with DIY speaker builds is that they tend to completely ignore directivity. That's somewhat understandable as it can be quite a chore to perform the necessary simulations or manual CEA2034 spins but it also tends to negate much of the builder's work. When a passive or DSP-based crossover are designed based solely upon an on-axis response without proper simulation or off-axis data, the result is typically severe directivity nonuniformities which produce a completely different listening window and in-room response when ERs are summed. Unfortunately, this is also a problem which can never be fixed after the fact using EQ.
Proper directivity matching really needs to take place when drivers are being selected, with a degree of passive control also being engineered into the baffle itself. Where possible, a waveguided tweeter simplifies much of the design process.
Hearing guys talk about off axis response and elevating it to make or break importance is getting old fast. Directivity and off axis response are important, but not the major factor it's being made out to be lately. And it's largely determined by two things: driver size (cone / dome diameter) and crossover frequency. In a two-way there's not a lot to mess up unless the drivers are grossly mismatched.
@@IBuildIt Directivity really is a make-or-break characteristic, as it is one of the few problems that can't be corrected after the fact. If the response of your early reflections differs drastically from that of the on-axis, then you effectively have a speaker with an unpredictable listening window depending upon the room. Studies published by Olive and Toole corroborate this, as it pertains to listener preference.
The pistonic diameter of the driver in conjunction with the chosen crossover point determines the widest achievable directivity but only given an infinite baffle.
The trouble is that crossing a directly radiating 20mm or 25mm tweeter over to a 5" or 6.5" midbass driver almost necessitates a directivity mismatch under most circumstances, as the Fs of the former will almost always place its usable passband far beyond the point at which the latter narrows. You mention that directivity is a simple matter for two-way designs but in practice, the vast majority of them lack smooth directivity for this reason and we now have access to a great deal of measurement data which shows this.
I just made a video talking about early reflections and my opinion on that research. Early reflections are destructive and need to be treated so that they don't corrupt the direct sound from the speaker. That's the make or break component in all this - reducing or eliminating those early reflections, and not trying to "optimize" the speaker to make the reflection (somehow) more acceptable.
Reflections are a distorted copy of what the speaker is putting out, and having more accurate off axis response can actually cause comb filtering to be worsened - two of the same signal arriving at a slightly different time will cause cancelations at some frequencies.
Sounds like all of what you understand about this comes second hand, and not from anything you've done yourself.
@@IBuildIt
Early reflections do produce comb filtering but above the transition point, it becomes so narrow as to exceed our Equivalent Rectangular Bandwidth (see Fletcher's paper) and in conjunction with HTRF, the result is a perceptually smooth but additive response.
Most listeners do not make use of room treatment and it is therefore critical that a speaker exhibits uniform directivity if it is to behave in a predictable manner above the transition point, regardless of the room. When designing a speaker, one does not necessarily have control over the eventual listening environment but directivity is a characteristic which we *can* control.
Arguably more problematic are late reflections, which serve only to raise the perceptual noise floor of the room and which can be seen in RT60 data.
There is certainly debate within the engineering community to whether early reflections are *beneficial* but your characterization above conflicts with the peer reviewed research that we do have. If you believe that you can demonstrate something which runs counter to existing research, then I would genuinely encourage you to publish a paper rather than debate the subject with me, a fellow non-expert in this field.
You mention that my comprehension comes second hand but the most effective means by which to understand *any* subject is to stand on the shoulders of giants. I could quite easily share my individual experience but it is my position that uncontrolled subjective evaluation is unreliable, regardless of the point of view for which one advocates.
Lol, publish a paper... what do you think this is? One learned professor talking to another? You can't see me, but I'm rolling my eyes right now :)
You can stand on the shoulders of giants on both sides of this issue. I'm not the only one saying early reflections are damaging - look at recording and mixing studios and the level of treatment used there to fight reflections and reverb.
And even better is to take the matter in hand yourself and listen to both environments. Set up some treatment and compare that to the non-treated rooms you already are very familiar with. Until you have, your opinion is just repeating back what's coming from someone else's mouth.
Most listeners don't actually listen to music or care that much about how it sounds. So tailoring loudspeakers for the masses will be a different task than setting up a listening room where how the music sounds is VERY important to the person listening. The research you are putting your faith in is for the masses, or people who (for whatever reason) prefer listening to their walls acting as speakers that play along with their speakers.
I have a set of Jantzen ja-8008 woofers to offer up for your use. They were designed by Troels Gravensen. Drop me a line if you're interested.
Im guessing the easy answer is like everybody you've got an excuse for everything
Must sound bright
The Sound Board ... maybe?
John the mic is always set to 1 meter on axis or off. Your sweep should be set to have 1 watt peak to peak @ 1Khz or 2.38 V p-p AC.. Then take your measurements. I guessing your using REW for your measurement software. Also try constructing a baffle behind the microphone . That will eliminate reflection at the measuring point. Enjoy your videos. Have a wonderful day.
The standard spec says you drive 1W and measure at 1 meter. 1W into 8 ohms is 2.83V rms which is 8V p-p. An RMS voltage is equivalent to a DC voltage when translating it to power. P=V^2/R. Power in units of Watts is not p-p or RMS, it’s just Watts.
Hi John, I tried to help you out on speaker measurement and how to do it consistency and to FTC standard for home audio. Yes I was wrong on the RMS voltage it is 2.83. Been in the hospital and I thought I remembered it off the top of my head. Again sorry was just trying to help you out.
I guess this sounds like "I trying to look like a smart asshole" but FR does not need to be a perfectly straight line until you like the overall sound. Peaks in HF segment can be a good thing by giving nice clarity feeling without tearing ears apart. It seems you have whole lotta work to do with lows, cause deep LF are highly underpowered. most sound companies trying to make V-shape frequency response this days. at least - this is what mainstream market doing. I`m sure you know that.
When you hear a problem in the high end and then measure the speaker and see a 10db peak at 8k, then you know where that problem is. Not looking for ruler flat, but as flat as possible within reason is the best target to shoot for.
The bass could be better (and I added baffle step correction to the crossover in the new one to fix that), but like I said these are only used for me editing video. And there's also so room gain.
Baffle step?
Don’t you want to measure in between the tweeter and woofer? The mic is right up on the woofer. Did you measure it like this? If you did of course the tweeter measurement will be way off.
That was the last measurement I took, called "nearfield" - it measures the output of the woofer only. The rest of the measurements happen with the mic 1 meter away from the speaker.
Why don't speaker manufacturers just post a graph now instead of a picture of the speakerz?! With the decline of av stores we have to unfortunately rely on only measurements now which is a shame. Measurements are absolutely not the end all be all but I guess that's what we have to work with right now. Oh well. At least its accurate.
SpeakyJohnny
Just trust your earholes young man!!
Heisz 4 Hertz
Not true, unless if its built off specs. It'd that simple
DIY Speakers will sound bad if you combine a soft woofer with a hard tweeter or the other way around.
cheap tweeters