tag:blogger.com,1999:blog-9776879462112615652011-07-09T02:39:44.613+10:00Boxes, crossovers, simulations, materials...Lechhttp://www.blogger.com/profile/17528983836667673464noreply@blogger.comBlogger131100tag:blogger.com,1999:blog-977687946211261565.post-75669364276052559182009-06-18T11:36:00.007+10:002009-06-18T12:41:45.833+10:00

After a lengthy hiatus — basically I took a break from doing audio and DIY stuff — I've recently (about a week before writing this) finished building a new active filter circuit.It is soldered on a PCB and replaces an older unit that I'd built up on a veroboard. The veroboard served us well for about 5 years, but finally konked out when the jungle of wire-wrap started breaking and a thick layer

Lechhttp://www.blogger.com/profile/17528983836667673464noreply@blogger.com0tag:blogger.com,1999:blog-977687946211261565.post-5134746805382781872007-07-12T20:51:00.000+10:002007-07-12T21:47:40.270+10:00

A common question that speaker DIYers have is: what materials should I use for building a speaker box? MDF (medium density fibre board) is one very popular answer. Plywood is another option. Then there's hardwood, glass, concrete – just about anything with a good combination of high stiffness, high density, and rapid absorption of high frequency kinetic energy.I once experimented with

Lechhttp://www.blogger.com/profile/17528983836667673464noreply@blogger.com1tag:blogger.com,1999:blog-977687946211261565.post-10536075123723635402007-06-18T12:16:00.000+10:002008-12-09T21:29:22.356+10:00

This topic has been done lots of times by different people, but I think it deserves to be revisited as there are a couple of things that often seem to be overlooked.SPL, maximum loudness and whatnot...This angle is usually pretty well covered. If you want lots of bass, then you need to work out how much air a speaker can move. As a rough indication, multiply the surface area by the maximum linear

Lechhttp://www.blogger.com/profile/17528983836667673464noreply@blogger.com0tag:blogger.com,1999:blog-977687946211261565.post-57836085641827397732007-06-07T19:00:00.000+10:002008-12-09T21:29:22.709+10:00

In an earlier post I started writing up some plans for a loudspeaker that I want to build...To summarize, it's a 3-way design with a somewhat classic choice of driver sizes: 25cm (10") woofer for the bass, 12cm (4.5") midrange, and a fairly standard 25mm (1") dome tweeter. They will have sealed enclosures so I won't have to deal with issues like temperamental tuning and a peaky bass response. For

Lechhttp://www.blogger.com/profile/17528983836667673464noreply@blogger.com0tag:blogger.com,1999:blog-977687946211261565.post-30116162139889837412007-06-05T15:55:00.000+10:002008-12-09T21:29:23.025+10:00

Well, I'm designing a new pair of loudspeakers. Basically, they'll be a pair of traditional 3-way loudspeakers that use 25cm (10") woofers housed in sealed boxes, 12cm (4.5") midrange speakers, and 25mm dome tweeters. (The original web page that I started about them can be found here.)I don't intend to build these loudspeakers any earlier than 2008 – partly because I'm a great procrastinator and

Lechhttp://www.blogger.com/profile/17528983836667673464noreply@blogger.com0tag:blogger.com,1999:blog-977687946211261565.post-50704176748553358902007-05-27T17:09:00.000+10:002007-05-29T15:25:03.149+10:00

Loudspeaker simulation/modelling programs are indispensable! One of the most important pieces of advice I could possibly give regarding loudspeaker simulators is: get one!Calculators and formulae for working out box volumes are better than nothing, but they don't give you a 'feel' for what happens when you alter various parameters. For example: a Javascript based calculator might recommend an "

Lechhttp://www.blogger.com/profile/17528983836667673464noreply@blogger.com0tag:blogger.com,1999:blog-977687946211261565.post-60975039222769255982007-05-26T14:28:00.000+10:002007-05-29T15:27:11.270+10:00

As the name implies, a labyrinth design is intended to channel the speaker's back-wave through a series of tunnels/tubes/openings and so-forth (like a labyrinth) until practically all of the acoustic energy is absorbed. Very little sound is reflected back to the speaker and thus the system behaves like an infinite baffle.It sounds nice in theory, but it's usually far from ideal in practice. At

Lechhttp://www.blogger.com/profile/17528983836667673464noreply@blogger.com0tag:blogger.com,1999:blog-977687946211261565.post-28234965110415112242007-05-26T14:18:00.000+10:002007-05-29T15:29:11.228+10:00

Vented/ported boxes are slightly different from sealed ones in that they have a hollow tube (or some other type of port or vent) connecting the internal air volume to the outside air.At low frequencies, ported loudspeakers have:Two masses – the speaker cone and the air mass.Two springs – the speaker suspension and the air spring.Two damping devices – electromechanical damping of the speaker, and

Lechhttp://www.blogger.com/profile/17528983836667673464noreply@blogger.com3tag:blogger.com,1999:blog-977687946211261565.post-79220270063770628162007-05-26T14:06:00.000+10:002007-05-26T15:22:34.675+10:00

A basic sealed speaker box usually consists of a hollow box and a large circular hole where the speaker is mounted.At low frequencies, the air and damping materials form an energy storage device – a mechanical spring – which produces an unavoidable resonance when combined with the spring constant and mass of the speaker cone. This resonance is usually exploited to optimize the low-frequency

Lechhttp://www.blogger.com/profile/17528983836667673464noreply@blogger.com0tag:blogger.com,1999:blog-977687946211261565.post-79693005838585602932007-05-26T13:04:00.000+10:002007-05-29T15:28:39.240+10:00

Designing an enclosure is a fundamental part of overall loudspeaker design. It's nowhere near as simple as building a "strong, solid box". A speaker box performs a variety of functions and some of them are actually not so obvious.Take for example: a speaker that's framed in a sealed hollow box, which has nothing but air inside it. What happens? How does it work? Why is the box necessary? Is it

Lechhttp://www.blogger.com/profile/17528983836667673464noreply@blogger.com0tag:blogger.com,1999:blog-977687946211261565.post-80847326775927327182007-05-25T21:43:00.001+10:002007-05-29T15:29:56.412+10:00

This seems to be a common question when choosing a speaker driver: what's the best cone material? Well, I don't think there's really any such thing as a "best" material – they all have strengths and weaknesses.One difficulty that speaker manufacturers have to contend with when designing their speakers is that they have to operate across a wide range of frequencies. At low frequencies (such as

Lechhttp://www.blogger.com/profile/17528983836667673464noreply@blogger.com0tag:blogger.com,1999:blog-977687946211261565.post-54022938953386562532007-05-25T19:43:00.000+10:002007-05-30T00:52:24.660+10:00

It's probably a good idea to do this step near the start – a loudspeaker project is one of those things where you won't get far unless you have a pretty clear idea of what you actually want to make. Look around on the Internet for sources of inspiration. Search through hi-fi journals, DIY forums, review magazines, other people's systems and what's available in shops...How about 2-way speakers? 3-

Lechhttp://www.blogger.com/profile/17528983836667673464noreply@blogger.com0tag:blogger.com,1999:blog-977687946211261565.post-46083500664922958172007-05-25T12:47:00.000+10:002007-06-05T16:40:26.668+10:00

This blog is all about designing and building your own loudspeakers. I don't consider myself a "self-styled expert" or anything like that – I just want to help and encourage people who are interested in the subject! So check out the posts, feel free to write comments and make suggestions and whatnot :-)Anyway, I find that writing about the technical aspects of loudspeakers, reading what others

Lechhttp://www.blogger.com/profile/17528983836667673464noreply@blogger.com0