4.5"+2"+miniAMT, 5.5"+2"+0.75", 6 "+ 2"dome+1"dome
Still looking for a 3"+1.5"+0.5" (only TB makes two inexpensive 0.5" domes)
Question: What is this 'ground plane" method of measurement? I found in a couple different places where guys stick the mic on the ground and the speaker on the ground and take the measurement of the woofer this way. I suppose the theory is that if the mic is on the ground it cannot receive ground reflections. Does this actually work? This seems like the best way to do it if it does.
My original plan for woofer measurements was to take the near field and far field, then raise the SPL level of the near field to the far field response, then remove the far field. This should give me a reflection free woofer measurement while keeping the phase and SPL the same as far field measurements of the tweeter and the woofer.
If one is very careful about technique, ground plane measurements can be made over the full spectrum all the way up to 20 kHz. But for most of us, it is most useful when used up to about 1000 Hz, and it is considerably easier to do if we don't try to go up to high frequencies.
A ground plane measurement mimics the response of a 4-pi anechoic measurement, but with a 6 dB increase in magnitude. Without access to a very large anechoic chamber, it is the only practical way to make low frequency anechoic-equivalent measurements at low frequencies.
A ground plane measurement mimics the response of a 4-pi anechoic measurement, but with a 6 dB increase in magnitude. Without access to a very large anechoic chamber, it is the only practical way to make low frequency anechoic-equivalent measurements at low frequencies.
???
Fully active makes no difference, the tweeters can both be playing at the same time.
dave
I didn’t measure it but i designed it and it works really well. No artifical acoustic treatments required.
dave
Good advice for some situations, but too general of a statement. What if I have multiple rooms that I might switch between? What if I'm making them for someone else, to be determined later... Child, nephew, sibling, etc.
Fabulous post you made Perry a couple of pages back.
There are two very different types of DIY units. There are those that you design yourself as well as build them. Depending on your design experience the results can vary widely. And probably won't be great at the start.
Then there are DIY units you can build according to plans provided by some extremely capable and experienced designers. A few names that come to mind are Dennis Murphy, Jim Holtz & Curt Campbell (Speaker Design Works), and the late Jeff Bagby. I'm of the firm belief that designs by these people are actually far superior to most commercially available products costing as much as 10 times the amount of the needed components.
So, it really depends on what the "D" stands for. If it stands for the Design, then you're taking a big chance on the outcome. But if it stands for Do, meaning essentially you build it to someone else's proven and quality design, then you can have a great outcome for a very reasonable cost.
Obviously your attempting to invalid me…Lol
And you like to argue the point.
To answer your question building a loudspeaker for the first time puts them in unfamiliar territory.
In unfamiliar territory a persons problem solving skill are significantly reduced. Just think about that for a moment. If you don’t understand in detail what it is or how it works or how to assemble it properly???
This is why ljkea can be a marriage wrecker.
They no nothing other than it got drivers, a box, a port and a crossover.
It’s in the details that the implementation can bring the end result unstuck.
They don’t really understand how to follow a schematic and they don’t wire it up right
L Pads for example.
Or they might not be familiar with how to get REW working properly or a particular situation. In LA a met a JPL engineer who wasn’t confident with REW or how to make measurements. We spent the afternoon with REW making some measurements and determining the polarity of a Tad compression driver. We then went through how to use REW to perform high resolution tests to adjust L pads . This resulted in a significant I improvement in the tonal balance and imaging.
He now has these skills.
Sometimes people do everything right but then can’t resolve why one driver they bought off EBay is not as louds as the other
They assumed it was fine because they were told it was fine. After a long process of elimination they didn’t figure it out. I was contacted and advised on a few measurements to isolate where the problem was. The driver was faulty. A new set of diaphragm were ordered and it now works perfectly.
Not everyone goes on Diyaudio.com or LHS looking for answers.
You may not care. But some do care.
The diy community has been running the Amp Camp for a number of years. This brings novices together and gives everyone the opportunity to meet experts and they get their amp going.
I don’t see building a loudspeaker that you are going to live with in your home any different.
I lot of people at home do a nearfield measurement with the mic 1/4 of an inch from the driver. It might seem the logical thing to do. Unfortunately only a narrow band of frequencies will be measured accurately. There are explanations and l will leave it to your resourcefulness to find out why. There are some YouTube interviews respected loudspeaker designers on why this is the case.
If you don’t agree that’s fine because no one will know. But you will have got it wrong and you won’t know it’s wrong either. Then one day you will read about the right technique and you will kick yourself. Why didn’t l learn more about it and figure it out properly at the start?
Why are you answering this post a second time? You did at post 131 and I answered at post 135. And I will say it again I am not trying to invalidate you. You have a lot of experience and can offer real help to people.
That said we have had a long time disagreement about how we view people doing DIY. I see you as overly pessimistic. As I said in the previous post. You come off to me as someone who thinks people can't think for themselves.
I don't agree!
And remember the crux of the biscuit is the apostrophe.
Look no worries
Rob 🙂
It happens every day. Newbies can’t typically tell whether something which has become popular also happens to be correct…
Most aren’t quick to call out that which is questionable, but when they do it becomes interesting, sometimes….
Rob,
So the truth comes out at last.
Im sorry l can’t help you resolve your issue. Just let it go. It’s an anomaly.
I don’t see any reason not to make my understanding clearer to you by giving example’s. l thought l was not reaching you.
Now you’re saying you don’t want to hear me by questioning my justification to make myself clearer. Just let it go.
I am not wrong. It just doesn’t fit your particular way of looking at something.
In future please be honest with yourself before you start questioning anyone else.
Being in a space like anything diy is about being collaborative, sharing experiences and helping some in need if you can and being open to diversity of thought.
In the early days l met someone online who provided anyone he met with a complete build plan of the Aleph 2 diy power amp. He was a doctor at Royal Adelaide Hospital down here. He told me everything l needed to know so l would succeed. Numerous others used this plan.
Today AllenB who is a wonderful advocate for diy audio knocks himself out every day by not just answering questions but by being helpful and offering guidance and advice.
That is what makes Diyaudio.com such a special place. Justin previously reached out to me when an order from the shop didn’t go quite as planned. He was incredibly helpful and kind.
I don’t see that l have ever done any different. Certainly not to the numerous testimonials l have personally received over the years.
So the truth comes out at last.
Im sorry l can’t help you resolve your issue. Just let it go. It’s an anomaly.
I don’t see any reason not to make my understanding clearer to you by giving example’s. l thought l was not reaching you.
Now you’re saying you don’t want to hear me by questioning my justification to make myself clearer. Just let it go.
I am not wrong. It just doesn’t fit your particular way of looking at something.
In future please be honest with yourself before you start questioning anyone else.
Being in a space like anything diy is about being collaborative, sharing experiences and helping some in need if you can and being open to diversity of thought.
In the early days l met someone online who provided anyone he met with a complete build plan of the Aleph 2 diy power amp. He was a doctor at Royal Adelaide Hospital down here. He told me everything l needed to know so l would succeed. Numerous others used this plan.
Today AllenB who is a wonderful advocate for diy audio knocks himself out every day by not just answering questions but by being helpful and offering guidance and advice.
That is what makes Diyaudio.com such a special place. Justin previously reached out to me when an order from the shop didn’t go quite as planned. He was incredibly helpful and kind.
I don’t see that l have ever done any different. Certainly not to the numerous testimonials l have personally received over the years.
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And what issue would that be? I don't agree with you so I automatically have an issue? You have never heard the phrase agree to disagree?
Your kidding? All we have here is a simple disagreement about what others are capable of. Control of what? What the hell are you talking about?
So what's your point. I am sorry are only your posts helpful?
Do you think your the only person who does that?
Did anyone say you did?
Why don't you get off your high horse and realize you are not the only person who has common sense or a functioning brain that can get from point A to point B
Rob 🙂
To get back on the original topic,
I took some old car audio junk I had sitting around from years ago (JBL GTO 804 subwoofer, 2 infinity reference 6032si speakers), repurposed a part of an ebike battery I found in the trash, bought a $20 amazon class D amp and $20 worth of battery control boards so I can charge it with USB, and built a bluetooth/aux powered speaker that has absurd battery life (like, a week? And well over 24 hours with it cranked) and sounds better than anything you can buy that costs less than $500. I had never done this before and had no idea what I was doing and still, it turned out great, I think I'd be happy with this even if it wasn't my first try.
And I made a bunch of mistakes along the way, probably made it bigger than it needed to be, and could've definitely put the battery inside it had I made it reasonably sized, but again, I had no idea what I was doing.
Now I wanna build version 2.0 w/ DSP and 1/4 the size, and see if I can make it sound just as good.
I took some old car audio junk I had sitting around from years ago (JBL GTO 804 subwoofer, 2 infinity reference 6032si speakers), repurposed a part of an ebike battery I found in the trash, bought a $20 amazon class D amp and $20 worth of battery control boards so I can charge it with USB, and built a bluetooth/aux powered speaker that has absurd battery life (like, a week? And well over 24 hours with it cranked) and sounds better than anything you can buy that costs less than $500. I had never done this before and had no idea what I was doing and still, it turned out great, I think I'd be happy with this even if it wasn't my first try.
And I made a bunch of mistakes along the way, probably made it bigger than it needed to be, and could've definitely put the battery inside it had I made it reasonably sized, but again, I had no idea what I was doing.
Now I wanna build version 2.0 w/ DSP and 1/4 the size, and see if I can make it sound just as good.
Simialrily i was talking to my stained glass buddy about videos where you have to know more than the presenter to tell when they are on target or spewiing misinformation.
dave
Hello
That's an issue with all forums, You Tube and Facebook. You can't depend solely on any of them as your information source. You need to read and find some good reference material. There are lots of people who do offer good advice and some who don't. Sometimes It's hard to know as a beginner who to listen too.
It's an open public forum it is what it is.
Rob 🙂
I have been reading these posts with interest. As a "newbie" often mentioned here and a relative newcomer to the forum may I offer another perspective?
Like many online forums DIY audio has a very diverse membership. To put it in an educational setting there are kindergarten kids to PhD students and everything in between. People are here for many different reasons. To use a Lego brick analogy, there are those who have a cupboard full of millions of bricks who enjoy building something from scratch using their own knowledge and imagination and there are those who just want to buy the latest Lego Star Wars kit and build the picture on the box. There is no right or wrong age or required background to take up an interest in speaker building and no right or wrong reason for doing so. Every kid who has built Lego probably started out with a simple kit and may or may not have progressed from there. This virtual community is as diverse as the real world and is all the richer for being so.
I took up speaker building above all because of an interest in music. Lossless streaming has literally opened up a whole new world of high quality music that the hifi world is only now coming to grips with. As a bit of a jack of all trades, speaker building appeals to me because it combines woodwork, electronics, acoustics, material science, engineering, aesthetics and creativity combined with a little magic to produce music. What a wonderful way to learn and maybe even something to be remembered by if your creations are good enough to be passed on to the next generation. I have just joined the local Men's Shed and intend to suggest speaker-building to the members there.
I am under no illusion that I am "building" speakers. Instead I am assembing speakers consisting of drivers designed and built by very talented acoustic engineers from around the world. The generous people on this forum like Scott and Dave who design and publish many plans for others to follow is what this forum (in my view) is all about and all credit to them for their selfless approach to this hobby. Member tolerance of newbie questions is amazing and (nearly!) always sympathetic. My only comment here would be that I see many people who are talking past each other, especially experts scaring off beginners with too much technical detail, acronyms or acoustic engineering principles which may be unnecessary for someone just wanting to put a driver in a box. Measurements are fine for those with equipment, but those without (or with Mac computers!) may need to be encouraged more towards the Star Wars kit approach until they grow in knowledge and confidence. More resources for the beginner in an easy to find place on the forum, including (as suggested above) a set of recommended (or even "Top Ten") plans would be very helpful.
Speaker-building can be very lonely, so this community is a very precious asset for me and I'm sure many others. Please nurture it!
Like many online forums DIY audio has a very diverse membership. To put it in an educational setting there are kindergarten kids to PhD students and everything in between. People are here for many different reasons. To use a Lego brick analogy, there are those who have a cupboard full of millions of bricks who enjoy building something from scratch using their own knowledge and imagination and there are those who just want to buy the latest Lego Star Wars kit and build the picture on the box. There is no right or wrong age or required background to take up an interest in speaker building and no right or wrong reason for doing so. Every kid who has built Lego probably started out with a simple kit and may or may not have progressed from there. This virtual community is as diverse as the real world and is all the richer for being so.
I took up speaker building above all because of an interest in music. Lossless streaming has literally opened up a whole new world of high quality music that the hifi world is only now coming to grips with. As a bit of a jack of all trades, speaker building appeals to me because it combines woodwork, electronics, acoustics, material science, engineering, aesthetics and creativity combined with a little magic to produce music. What a wonderful way to learn and maybe even something to be remembered by if your creations are good enough to be passed on to the next generation. I have just joined the local Men's Shed and intend to suggest speaker-building to the members there.
I am under no illusion that I am "building" speakers. Instead I am assembing speakers consisting of drivers designed and built by very talented acoustic engineers from around the world. The generous people on this forum like Scott and Dave who design and publish many plans for others to follow is what this forum (in my view) is all about and all credit to them for their selfless approach to this hobby. Member tolerance of newbie questions is amazing and (nearly!) always sympathetic. My only comment here would be that I see many people who are talking past each other, especially experts scaring off beginners with too much technical detail, acronyms or acoustic engineering principles which may be unnecessary for someone just wanting to put a driver in a box. Measurements are fine for those with equipment, but those without (or with Mac computers!) may need to be encouraged more towards the Star Wars kit approach until they grow in knowledge and confidence. More resources for the beginner in an easy to find place on the forum, including (as suggested above) a set of recommended (or even "Top Ten") plans would be very helpful.
Speaker-building can be very lonely, so this community is a very precious asset for me and I'm sure many others. Please nurture it!
For a few decades, I felt improving the room would make the greatest marginal gains. Studied guys like Everest and Newell.
Finally had the opportunity to build a room from ground up, as an attached addition to main house. Interior dimensions were laid out to the inch, for best modal dispersions. Large room, >300 m^3. RT60 leveling absorption and diffusion part of the design.
Wonderful sounding room. Put prosound speakers in it for multi-channel. Had a bit of loose coin then, and used same stuff Broadway and Nashville theatres were using. Dialed it all in further with measurements.
Really wonderful powerful sound.. Figured I was done.
Then I made the mistake (or rather the fortuitous leap), to take some of the speakers outdoors for big party.
Damn! So much better than even the wonderful room.
Ok, since then....I've come to realize rooms both suck, and don't suck. Suck in terms of no matter how good, they degrade.
Don't suck, in terms of unless they are really bad, our brain makes the most of it, and we becomes happy campers after all.
What I'm trying to impart...is balance and not thinking rooms matter so dang much. I'll definitely take a good speaker over a good room.
Hello
I can see where you are coming from. When I first started I knew nothing. So asking questions many times led to answers I didn't fully understand. After you have been doing this for a long time you don't think like a beginner.
The tech talk makes it easier to communicate with more experienced builders but not someone fresh out of the gate. At some point everyone can fall into this trap from time to time. I am not the most experienced builder by a long shot but I know I have from time to time. I think we all do. Not all people are good teachers. That's a gift.
WRT Kits
Kits are fine but they also have serious limitations. Depends on what your goals are.
If are looking for the satisfaction of "Yup I built Those" perfect!
If you want to get into more serious DIY it's a place to start. The issues is you are assembling to an instruction sheet. There is limited learning involved.
It's fun going through the parts resistors, caps, inductors, PCB the drivers a precut cabinet it's quite the project especially the first time!
All of the decisions to make the kit a successful loudspeaker have been made for you. You are insulated from the design process. If you want to go beyond that you are going to have to work for it. Good place as a start look at the sticky threads. Start reading and ask a lot of questions.
Top 10 kits sure but to become a scratch builder the kits alone won't do it.
Rob 🙂
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For many of us, designing and building loudspeakers is a journey of discovery. The journey is one of the main goals. The end result (a good sounding speaker) is a goal too, but the journey is a major point. We do this for fun and enjoyment. We have no schedule but our own, and no budget but our own. We define our own design goals, our own specifications, our own mission. We get satisfaction from both the end result, and the journey to get to that result.
On the other hand, there are some of us who want to build one set of speakers and want to save money by building it themselves. These friends are not interested in a learning process which stretches over years. Building a preexisting design or kit makes the most sense for these folks.
j.
On the other hand, there are some of us who want to build one set of speakers and want to save money by building it themselves. These friends are not interested in a learning process which stretches over years. Building a preexisting design or kit makes the most sense for these folks.
j.