Thread: Crossover

Depends on whether your aim is to achieve a decent audiophile quality speaker or to have something you put together yourself. One option is simply to buy ready made crossovers, in which case you build the speaker box, buy the speaker units, crossover and cables, and basically solder them together. This takes away one significant variable in the tricky art of building a well balanced speaker.

Matching drivers to cabinets is as important as selecting crossover frequency and type, how do plan to approach that?

I would suggest that you check through HI fi and electronics mags to find project designs. These have driver and crossover kits available through electronics store and either cabinet kits or cabinet plans to go with them.
Locate a range of kits, select based on available space, performance and cost basis, then decide whether you want to built cabinets from scratch or assemble kit cabinets.

You can buy individual drivers and crossovers, but getting a good match btw drivers, crossovers and cabs may not be easy.

Download a free program called WinISD, It has a basic Xover calculator.
It will get you started, Xovers are the most technical thing for a newbie to get their head around!

I have seen numerous speakers that can be built using plans and buying the drivers as in this site....http://www.humblehomemadehifi.com

In all the speakers the crossovers are (to me) the most complicated part and in some there are various options. I know zip about this stuff and couldn't even begin to decide which one, let alone build it, try this for instance

http://www.humblehomemadehifi.com/DD8-MkII.html

I am not saying I want to build that speaker but it indicates what I find confusing, multiple crossover choices and if I do decide I have no idea how to build them. Thanks for the responses so far.

The building of the crossover is all that difficult, as long as you stick with reasonably simple configurations.

What takes the time is selecting the best point at which to crossover.

usulay you need to look at the curves of the various components and cross at points that chop out the nasty bits..... all speakers have nasty bits....these will be where you start to see peaks and dips or the response drops away rapidly or in the case of mids & his where the speaker is incapable of dealing with the low frequencies at the power required.

Hell there are whole books written on this..... and heated arguments for days on various forums.

start with a simple two way design and learn from there.

there is more trial & error in this than most would have you believe.

the equasions for two way crossovers in single and two pole crossovers are realy quite basic.
you can buy a selection of basic crossover components from jaycar & altronics... and jaycar have PCB's to build on.

I have wound my fair share of crossover chokes but the problem for the average bloke is getting winding wire in suitable quantities.

Often the choices are more or less made for you by the combination of component values available to you.

I will make one recomendation though.
use polyester caps ( green caps ) in preference to electrolytics... gettng big enough ones may be a fiddle.
Or if you must use electro's.... bi-pass ( put in paralell with them) them with a low value poly cap to counteract the self inductance of the electrolytic.... the value isnt important....anything insignificant to the calculations will be fine.. .1uf would be a start

most of the crossovers i've built have been big high power jobs for pro work...

also remember it is as important to ballance the output level of the drivers, either by selection or attenuation.
even if the crossover point is correct.....if a tweeter is screaming its head off the box will still sound rubbish.


books books books.... get into some books.

cheers

The equations are relaly quite basic but they don't often work, getreal mreasurements then apply some stock crososvers and see what frequny response you get... yuk.

yep... trial and error and stock crossovers would only produce mediorce results unless you are very lucky.

$100s of dolalrs u'd spending tryin gto get good results with trial aned error ud be better off buying some measurment stuff and using that plus speaker workshop.

unce you have that measur the linear distoretion (frequnycy response) and non linear distortion (harmonic distortion will do). choose ur crossover point and filters in order to get a good balance between flat power response (total ona nd off axis frequeny response), low distortion (tweeters crossed over too low will tend to distort, but the measurements will tell u this) and on axis repsonse. possible), but not so low the tweeter distorts.

If ur using metal cones you'd need a notch filter...

everything will soudn tinny unles su use baffle step correction, the right amount of it will dpened on ur room and how far out the speakerss are, so trial and error her is ebst. you can get hte right correction by making the lowpass inductor larger, rather than using a seperate inductor and resistor..

if ou want flat response or tiling down or even up will denpend on ur room acoustics, how much distoriton the teeweters generate and the off axis response of the tweets. The vifa xt-25 for example has rapidly falling off axis response, so for flat power resposne the overall on axis response pattern mght have to be tlted up.

when you are buying drivers i'd find some measurements (linaer and non linaar) to help for an informed descion.

Good luck with it

Thanks for that Audioguy and I think I had better re-phrase my question. I don't want to do this as a serious hobby, I want to make a set of 2 speakers strictly for music that perform rather well, as a one off. At this stage I don't want to build a system for TV's, I just don't want to get into all that stuff so how do I go about this? I need to buy the drivers and crossover in one kit, There used to be a supplier in SA, I forget the name (V....?) who did this it but now unless I am mistaken they supply cabinets and all.

Hi Mini,
I think the company that you are referring to is Vaf Research www.vaf.com.au/ I bought one of their "kits" a few years ago. They supply drivers, crossover components, plans & cabinets. You save a little bit by assembling yourself. They supply nice stuff.
Cheers.

BB, yes that's them. They used to do the kits with plans for the cabinets, not so these days by the looks of it.

You could also look at theloudspeakerkit for australian kits...

A decent measurement setup can be had for as little as $200, but since this is a one off thing, i reckon that finding a pre-done design might be the best bet... Buying a kit means that whoever is selling it still needs to take amargin off hte top. I reckon you are reasonably confidant at woodworking, since you are posting here...

You could get all teh compents from WES components, what is your budget? Without a budget its a bit hard to send you in the right direction.

http://www.zaphaudio.com/ZD5.html

could be really good if they arent out of budget, the design is well explained, and all hte bits could be gotten from wes components. I'd folloow soundmans advice and wind your own inductors(chokes) (look for a motor rewinding buisiness), it is 1000% cheaper than buying your own inductors.

I buy most of my speaker parts from the States (sorry local suppliers?) one good source is Madisound and one of their services is Crossover Design – see - http://www.madisound.com/services/leap.php - between US$30-60 it may save an awful amount of time and heartache?


Cheers - Phil