Some rather good sound

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white exec
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Some rather good sound

Post by white exec »

Apologies up-front for this having almost nothing whatsoever to do with French Cars . . .

During the last couple of years, I've built some modest-sized hi-fi speakers - two of the pairs to provide good sound to go with flat-screen tv's.

The units were made from 19mm MDF, and the speaker drive units themselves were 1 x 5" Pyle Pro PDMW5, and 1 x Motorola-type rectangular piezo tweeter - plus (unusual for piezo tweeters) a very simple crossover - plus a port.

I've now made three pairs of these, and I must say that the sound from them is outstanding. The drive units work together splendidly, and the crossover really does something a bit special.

If anyone is interested in the very straightforward design, I am happy to post details. Construction is easy for anyone with a woodworking facility.

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CitroJim
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Re: Some rather good sound

Post by CitroJim »

Chris, yes I am, very interested indeed :D I have built speakers - guitar ones - in the past and I find it a very pleasing and satisfying activity despite my wood allergy...

Surprised a Piezo tweeter being used with a crossover... I must confess I never have but always very happy to learn something new...

Is the crossover more intended to keep high treble out of the bass/mid-range speaker or vice versa? If the former then that makes sense to me thinking about it...

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white exec
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Re: Some rather good sound

Post by white exec »

Yes, I think the crossover does do that, although it contains nothing inductive.
There a two web articles that I found really useful in making these units, and one of them covers the thinking behind the piezo crossover. The other is a versatile and hrlpful interactive formula for properly calculating dimensions of the cabinet and ports, given the drive unit parameters that you are going to use.

I'll knock together the construction details in the form of a Word document, and include the web references. Will also keep it simple enough with details of the dimensions I used with these two drive units.

Hell Razor5543
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Re: Some rather good sound

Post by Hell Razor5543 »

This may sound silly, but somebody I knew read an article that intrigued him, so he went and tested the theory. It turned out to be true. What the article was about was how good the various speaker cables were (and a few other options). Two of these options were lawn mower cable. The normal cable was not very good, but the modified one was comparable to the high quality cable. The way the modified cable had been 'tweaked' was by running a blow torch along the cable until the outer insulation charred. My friend believed that this resulted in the surface of the copper wire getting tarnished, improving the connectivity for some reason.

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CitroJim
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Re: Some rather good sound

Post by CitroJim »

Hell Razor5543 wrote:This may sound silly, but somebody I knew read an article that intrigued him, so he went and tested the theory. It turned out to be true.
I do the same James... Never take things at face value me... I once did a load of listening test to see if different makes and ages of ECC83 (12AX7) valves sound different in a guitar amp as was claimed by many...

And if the legendary 'black-plate' Mullard ECC83 as made in Blackburn did indeed sound better than anything else...

It turned out to be true and I could indeed hear a difference, especially when driven into distortion...

So, some of these apparently wild claims do indeed have some bearing on reality...

Chris, looking forward greatly to your document :D Thanks ever so!

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white exec
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Re: Some rather good sound

Post by white exec »

I promise a blowtorch plays no part in this project [-(

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Re: Some rather good sound

Post by dnsey »

The difficulty with testing these sorts of claims is eliminating the psychological element - placebo effect, if you like.
Only a proper double-blind test is really reliable in proving that you're not simply hearing what you expect ( or hope for).

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white exec
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Re: Some rather good sound

Post by white exec »

Some things are objectively testable, and that includes how different types of speaker cable behave. You don't have to spend a fortune on decent cabling these days, and it's one of the cheapest improvements you can make to many systems. What does decent chunky multi-strand cable give you? - Richer bass and cleaner treble.

Always amazes me how many new audio 'systems' today are still being sold with what I would describe as "bell wire", even on stuff selling for £200-plus. It's just cost-saving by the manufacturer, who knows full well that most buyers know no better.

A-B (double blind) testing can be intriguing. A friend of mine, who went on to spend most of his life working for RS, has - more than once - purchased a brand new CD player, only to open it up (warranty to the wind) and study the capabilities of its built-in power supply. Finding corners cut, he then went on to construct his own immensely stable and resilient power supply, sometimes the size of the complete original unit!

Crazy? Worth it? Well I asked him just that question, and so he sat me down to do a blind test. Same top-quality music CD, same CD player, same amplifer and speakers. All I had to do was sit there, and throw a small switch to flip between one power supply unit and the other. And the difference? Gosh: richer bass, clearer detail, crisper highs, and everything feeling just more involving. Crap original product? No, a £250 Sony deck, then one of the best available.

I'm not that much of an audio anorak, but can tell the difference between grim, acceptable and outstanding. I've also tried to look after my hearing over the years, and have been lucky so far in that respect.

It's also interesting how good sound can have an effect on the way we see things. Back in the Seventies, as Betamax was being launched, Sony conducted some research, asking people to rate the quality of their Trinitron television sets, operated under "various conditions". The only difference in the "conditions" was the quality of the sound being relayed. Guess what? Folk rated pictures to be better quality if the sound was better!!

Cinema learned that lesson too, which is why you are now subjected to a multi-channel audio assault whenever you go to a commercial cinema.

Unfortunately, flat-screen tv manufacturers have more or less abandoned any attempt at decent sound, in the quest for thin displays with tiny surrounds. Or perhaps they just want to sell you audio equipment as well.
Last edited by white exec on 04 Dec 2016, 09:29, edited 1 time in total.

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Re: Some rather good sound

Post by elma »

I'd love a copy of that word document. I've always thought home made speakers would be a satisfying project.

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CitroJim
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Re: Some rather good sound

Post by CitroJim »

white exec wrote:I promise a blowtorch plays no part in this project [-(
Aww, that's a shame :( I'm good with a blowtorch too... :lol: