Diy Question thread

If there are any specific questions that any of you audiophiles need to ask, regarding your circuit designs,or diy speakers post them here :

(Of course the pre requisite is a basic knowledge of electronics.)

 

No No No ......

you post your ideas here and then we comment or offer advice, not the other way round.

As Ripley said in Aliens " Have IQ's suddenly dropped round here "

 

why do you need a basic knowlege of electronics to build a diy speaker?
is it not diy if you buy the crossover?

why do you need a basic knowlege of electronics to speak to you?

why would someone ask you an electronics question if they knew nothing about electronics anyway?

 

Its relatively simple you tell us about your stuff and normally you'd get a few sage words of advice or comments about the design.

or like me you place items on here that maybe of use to others ie cable recipes or Wow that new vol pot has realy opened up the sound sort of thing.

 

Why don't you actually design hifi and stop mucking about ?

This is what I meant by tinkering.

Are you competent enough to build an amplifier ?
What do you recall from the physics you did in university ?

 

No. Loudspeaker design requires a basic knowledge of physics.

Why would you buy a crossover when you can build a 1st order crossover using a couple parts ?

 

why don't you at least tell us what you have designed and stop mucking about johnny?

what is it?
is it a new design?
in what way is it new?
why is you modifing a marantz cd6000 any different to what zanash does?
apart from the fact he can prove that he has actually done something and to a very high standard.

you are going to have to let something out if you are to keep up this "I am an expert" business or you will start to look very silly.

 

hmmm yes come to think of it my speakers sound better because I have filled them with uraniumhexaflouride, or is that nuclear physics.?
they glow a nice colour though. oh and you said electronics not physics.

about the crossover ?? read the thread again.

 

Hi,

Given your statement that you use PMC Monitors, why do you use speakers designed in direct contravention of the basic requirments to ensure a reasonably uncoloured reproduction of sound in acoustcially small rooms that have not extensivley "passivated" (in other words rooms that are not anechonic chambers and speakers with an excessively wide and variable dispersion)?

Do you not particulary like the way the actual recordings sound?

L8er T

PS, I find opposing your line of argument as irresistable as V in the comic and film found fighting "the system" irresistable. I hope I can forgiven for that and I hope you can, come the judgement no-one but you deliver, before the wheel turns for another round, you can forgive yourself, for no-one else can.

 

actually I am wrong I needed a basic electronics knowledge to rebuild some quad esl 57 electrostatic panels and voltage multiplier circuits once, so I guess you were right.

what do you know about electrostatics?
ever thought of building some direct drive monoblocks to do away with the audio transformer? something along the lines of "the beast" maybe?

 

Hi,

ABSOLUTELY.

I am not sure your writings make any sense at all.

There is no such thing as a first order crossover, unless you in effect combine two full range speakers.

As most drivers are 2nd order bandpass systems acoustically, the usual minimu oder of acoustic crossover to use is a 3rd order transtitional one.

Crossovers need to allow for the inherent driver response to produce the neccesary ACOUSTIC output that allows the output from drivers to integrate.

Once you realise that you also appreciate that relative placement of drivers plays a role.

There is nothing written that prevents a DIY Kit or design from meeting the prerequisites and equally, there is nothing written that ensures that commercial productsmeet them.

L8er T

 

What do you think pete would say about pmc's being ''speakers designed in direct contravention of the basic requirments '' ?

The transparence loudspeaker you designed would give far more varying results than the pmcs would in different rooms.
Would the transparence loudspeakers even work in free space ?
I doubt it given that they are open baffle designs.


''Do you not particulary like the way the actual recordings sound?''

I actually asked you a related question, and the reply you gave to me was that certain recordings, such as electronic music have no real world reference standard to compare the sound of the r ecording, which means that there is no right or wrong way it should sound.

Let me attempt to answer your first question.

I use them because that's what I have available to me at the moment. There is no speaker on earth which doesn't suffer from one problem or another. It's a compromise.

Can you reccommend a loudspeaker which is not in contravention of the basic requirements ?

 

That makes no sense to me.

Why should the minimum be 3rd order ?

I'm not talking about acoustically,I'm saying that the most basic is using an inductor and cap, in series with bass and tweeter respectively. That would work, although not effectively.

 

johnny said "I'm not talking about acoustically,I'm saying that the most basic is using an inductor and cap, in series with bass and tweeter respectively. That would work, although not effectively."

why would you do that when you could buy a 2nd or 3rd order one?

see earlier post.

 

Hi,

I'm not surprised.

Because all drivers available are 2nd order bandpass devices (some, like some drivers I work with now have a higher order rolloff) naturally. Enclosure modifications (from "sealed") can adjust the lower end bandpass behaviour and other other issues may increase the HF rolloff past that, but 2nd order is the absolute minimum with no crossover applied.

Add a first order electrical crossover and you are up to 3rd order final rollout.

Of course, you may have drivers with a flat response at least two octaves past the crossover frequency (in other words a tweeter flat down to 500Hz and a woofer flat up to 8KHz for a 2KHz acoustical crossover) except com mon driver makers show a deplorable lack of suchlike devices.

I am, because nothing else actually matters.

L8er T

 

Firstly, I wouldn't use a first order. So your assumption that I would is incorrect.

Secondly, why would you use a second or third order when you can just use a single cap in series with the tweeter, if you chose the drive units and construction very carefully, and even avoid the phase issues associated with higher order designs ?
In fact, some hi end speakers do.

'' Make everything as simple as possible, but not simpler.''

~Albert Einstein

 

you said :
"Why would you buy a crossover when you can build a 1st order crossover using a couple parts ?"

and the rest was a wind up not a discussion.

 

Hi,

It may surprise you, but whatever pete says concerns me little

Forgive me for saying so, but you have no fecking idea what you are talking about.

They are not meant to be used in free space, but they are meant to be used inside acoustically small (eg. anything much short of a concert hall) rooms.

Public Address are meant to work in open air (actually, even these rely on "floor bounce" reinforcement [or two pie radiation angle for the cognescenti]), domestic speakers by definition of the application are placed within a fairly small space, acoustically speaking.

There is however the "original studio sound" in this case, which exists either via nerafields or via highly directional far field monitors (or something inbetween).

I can live with that. In fact, I do.

Sure. And it is an active Studio Monitor to boot.

MEG RL901K

Can be auditioned in North London @ KMR...

L8er T

 

I don't agree that sealed can 'adjust' the bass response. The only thing it can do is curtail it, which is undesireable is it not ?

Well there was a confusion over terminology. I was talking about the electrical crossover whereas you were referring to the acoustic output, which as you correctly stated is always a bandpass or sometimes naturally a butterworth type filter.

 

Could you explain why the MEG RL901K have that particular radiation pattern in the bass frequencies ?