Hello to all. My name is Koulle. I have been tasked with providing a plan to turn some Volvo Dynaudio 4ohm car speakers into "world class" bookshelf speakers. I have been reading J. D'Appolito's "Testing Loudspeakers", wondering if I could find a handle to create a flow chart to the dark art of speaker building with ones own drivers. Can't get off first base. So here I am posting a short intro and hoping that I may borrow valuable information from you. So, thank you in advance. Suggestions as where to begin in terms of where to post my first question would be appreciated.
Howdy Koulle, welcome to diyAudio.
There are certainly a lot of speaker gurus around here, who will probably bury you in all sorts of sophisticated technical and analytical approaches. I would think start in the "Loudspeakers" forum, probably muti-way. They will probably want you to start with some sort of measurements with a microphone, etc.
I like building speakers using drivers I have on hand, but a major obstacle is that it is impossible to find "Thiele-Small" Parameters that would allow you to plug them into a program like WinISD and compute what size of sealed or ported enclosure will give you the performance you need. I'm a cheap redneck, without a lot of money, and I really don't want to play with a lot of complicated software, so I typically take a simple, practical approach. You start with the woofers, and need to find what volume box works best for them, typically a sealed cabinet, which will be smaller. (for ported you need to do more analysis, or measurements, or a lot more experimentation and the cabinet will be larger.) I cut a sheet of 3/4" plywood or OSB that I can mount the speaker on with a gasket so it is sealed, them experiment placing the plywood over the top of different boxes, enclosures, buckets, totes, whatever you can find using a towel to seal between the plywood and the enclosure. I will sometimes use a 5 gallon plastic bucket or smallish barrel, etc (the sides won't expand, but bottom will so put it on a folded rag and press down hard) and after each trial add uncompressible objects (like rocks, etc) inside to decrease the volume until you find the sweet spot. As you approach the right volume the bass will tighten and be stronger, more clear, more defined, less boomy or stuffy, etc. Once you get the right volume, you can fill the bucket up with water (with the rocks still in there), dump it out and measure how much water- that's your volume. There are lots ways to do this, I know it sounds pretty silly, but I've done it and nothing beats being able to find just the right volume by ear. If you can't find it by ear, software certainly won't do any better.
Once you know your cabinet size for the woofers, the mids and tweeters are typically sealed back, and the rest is microphones and crossover design.
Take care, and welcome.
There are certainly a lot of speaker gurus around here, who will probably bury you in all sorts of sophisticated technical and analytical approaches. I would think start in the "Loudspeakers" forum, probably muti-way. They will probably want you to start with some sort of measurements with a microphone, etc.
I like building speakers using drivers I have on hand, but a major obstacle is that it is impossible to find "Thiele-Small" Parameters that would allow you to plug them into a program like WinISD and compute what size of sealed or ported enclosure will give you the performance you need. I'm a cheap redneck, without a lot of money, and I really don't want to play with a lot of complicated software, so I typically take a simple, practical approach. You start with the woofers, and need to find what volume box works best for them, typically a sealed cabinet, which will be smaller. (for ported you need to do more analysis, or measurements, or a lot more experimentation and the cabinet will be larger.) I cut a sheet of 3/4" plywood or OSB that I can mount the speaker on with a gasket so it is sealed, them experiment placing the plywood over the top of different boxes, enclosures, buckets, totes, whatever you can find using a towel to seal between the plywood and the enclosure. I will sometimes use a 5 gallon plastic bucket or smallish barrel, etc (the sides won't expand, but bottom will so put it on a folded rag and press down hard) and after each trial add uncompressible objects (like rocks, etc) inside to decrease the volume until you find the sweet spot. As you approach the right volume the bass will tighten and be stronger, more clear, more defined, less boomy or stuffy, etc. Once you get the right volume, you can fill the bucket up with water (with the rocks still in there), dump it out and measure how much water- that's your volume. There are lots ways to do this, I know it sounds pretty silly, but I've done it and nothing beats being able to find just the right volume by ear. If you can't find it by ear, software certainly won't do any better.
Once you know your cabinet size for the woofers, the mids and tweeters are typically sealed back, and the rest is microphones and crossover design.
Take care, and welcome.