Sorry another newbie build thread

[soupdragon]

Ello all,

I’ve been pondering a speaker build for the last 6 months and while these forums are a great resource although you’ve almost scared me off

While I’m not an audiophile and don’t have that level of kit, I would best describe what I want as “decent sounding” I’m currently using a nad 3020 with some 2 way kenwoods I got in the mid 90’s the amp has changed a few times but the speakers have remained, I also use a cheapy richer sounds gale 8” sub to cover the lower end of things, this tends to get used for either vinyl or mp3s and gaming on my pc. My initial thoughts were to build a smallish 2-way PA type speaker a 7 or 8” driver in a mid size stand mount either ported or sealed, The idea being i would be able to ditch the sub and the pain in the backside wiring it needs.

Having done some thorough reading of threads here it would seem that picking my own drivers is a no no as the crossover design is somewhat more of a complex beast. I appreciate that the advice to folks in my position (1st build) is to follow an established design. Looking at alternatives I started thinking about full range using some tang band bamboo drivers but this approach would probably mean keeping or upgrading the sub



So now I have a few alternatives. I ask the advice of folks here as to which is worth pursuing

1) Build a system to my original idea either by finding some plans that fit the bill or use a pre made crossover which seems a sin here so I’m interested as to how bad it could end up this way.

2) Something with a fullrange driver, Cyburgs Needle took my fancy looking at the different designs. but this approach would mean keeping my sub and I have no idea of how a fullrange would sound.

3) I had an idea of building something using a fullrange driver such as this Tang Band W5-1611SA with one of these Tang Band W5-1126SC in the same enclosure to cover the lower end of things. This would be in a ported enclosure. I’m not sure if this approach would work but in my (limited) understanding the crossover should be a fair bit simpler

4) It occurred to me that I could give my current speakers a new enclosure with identical dimensions internally to what they are in now, to spruce em up a bit and to get that “shiny new thing”TM feeling. I might undertake this aswell as a new build in order to get a handle on speaker building its more a case of whether this is worthwhile and how much scope I have for messing with the enclosure design



I have a basic understanding of the concepts involved in building speakers and diy audio in general but having not dipped my toe in the water as yet I’m learing from new on pretty much everything, So please be gentle.

Ta in advance

[HK26147]

You left out another alternative:
Buy a kit that includes drivers and the designed crossover for them.
Some kits have you make the cab, some include completed cabs or "knocked down" for your assembly.
You have the advantage of the experiences and reports from an existing user base.
I'm not sure what you have available in the U.K. but in the U.S. you have inexpensive kits from Parts Express to more upscale offerings from Madisound and Zalytron that have been created by top designers.
This is a fairly safe DIY entry path, and can save money and frustration, on a 1st effort. Confidence builder too.
My 2p

[PeteMcK]

pre-made crossovers - would be totally hit & miss
'fullrange' drivers - don't cover either freq extreme & tend to be shouty in the upper mids, which requires a filter...
a stand mount takes up the same room as a floor stander, if you want to ditch the sub build a 2.5 or 3 way, which will need a reasonable sized cab, & because these are somewhat complex, follow an existing design.
If you want to learn about crossovers, I'll post a bunch of links that will help.
If you want a step up from your existing speakers, be sure to use good quality drivers in your build - this makes a huge difference,
cheap drivers can be made to do pretty good stuff, but nowhere near as well as well designed ones.
Depends on whether you just want a good pair of speakers, or want to learn about the intricacies of design - you've obviously done a lot of reading here, so I suspect a bit of the latter?

[PeteMcK]

While I'm still awake:
Getting started in Crossover Design

The basics (You've got to understand the rules before you can break them :-)
http://sound.westhost.com/lr-passive.htm
choosing xover point:
http://www.speakerbuilder.net/web_fi...xpointmain.htm
Baffle Step Compensation: http://sound.westhost.com/bafflestep.htm

Getting it done:
Jay has a page on designing xovers using manufacturers specs without measuring:
http://www.geocities.com/woove99/Spk...esigningXO.htm

Calculators:
http://ccs.exl.info/calc_cr.html#second
http://www.sengpielaudio.com/calculator-Lpad.htm

Measurement freeware:
Synrta - http://libinst.com/SynRTA.htm
ARTA http://www.fesb.hr/~mateljan/arta/download.htm
ARTA Jig - http://zobsky.blogspot.com/2008/01/s...t-jig-for.html

Examples from the designs of others can be quite instructive:
http://www.zaphaudio.com/
http://www.troelsgravesen.dk/Diy_Lou...r_Projects.htm
http://www.rjbaudio.com/projects.html
http://www.humblehomemadehifi.com/

[Moondog55]

OK hers a thought for you.
make a couple of lists, the good points of your current set-up and the bad points.
Make another list, what you want to acheive, maybe check yor bank balance.
If you are happy: almost; with the sound of your mid perhaps we can help you tweak it, if its the messy wiring that makes you unhappy perhaps you can make it permanent{- incorporate the existing sub ( I assume you have a powered unit with built in crossover and speaker level inputs and outputs )

One of the first things I do when I aquire a set of spekers is to pull the woofer out and have a look inside the box. and I have to assume here that it is a box and not injection moulded plastic.

Cheap boxes can be improved withsome little low cost tweaks that are in themselves a lesson and part of the learning process.

If the boxs are just that, glue blocks set in the corners can help a lo and cost little except swearing angd cursing and a little glue.

The next simple tweak is a little damping inside the box, foam. or BAF or polyester wadding or fibre glass; all have been used, and often the foam can be salvaged from packaging, air conditioning ducts use a polyester insulation that works.
There are lots of things you can do before you build your firt pair.
regards and welcome
Ted

[soupdragon]

Cheers for the replies & links I’ve had a brief skim through and given that I’m more competent with a router than a soldering iron (and not so great with either). Its kinda made me decide that a complete new build is probably not the best thing to get my feet wet with. So my plan is to go with building a new enclosure for my current speakers which have served me well. I have no idea where the stand on the scale of nice > nasty but I’m pretty happy with what they do and what they are.

They are pair of Kenwood LS-200G speakers seemingly unknown to the internet, our friend google doesn’t seem to know what they are

These are specs I got from the attached german product flyer

2 way bass reflex design
130mm woofer
25mm dome tweeter
Impedance 4ohms (an oddity to me)
Frequency response 60hz – 20Khz
Sensitivity 87 db/w/m
Crossover Frequency 3500hz

And now to save myself 4000 words

The speaker itself



The woofer







It looks terrible in the pics, they aren’t in the cleanest state in the world but black things + flash makes em 10x worse

If I were to keep the internal dimensions and port the same I imagine the build should be pretty straightforward

I’m also interested in what scope there is for adjustment to the design keeping the current crossover and drivers

[soupdragon]

Sorry for 2 consectutive posts my other is under moderation so i cant edit it

@ moondog, what you suggest is pretty much what I did i decided that its one of my major reasons was to replace the somewhat battered speakers i had atm so a new enclosure should solve that.

sound wise I'm pretty content with both the speakers and sub but I'm not opossed to doing some tweaking

The wiring of the sub is my main irk really as the amp has no pre outs so i have to use either the high level inputs on it or i have in the past used the tape loop

I've posted on the amp forum asking about the feasability of adding some pre-outs to the amp so i'll see how that goes

[Moondog55]

Sorry; but I'm a little confused by the pictures, which is the woofer you'll be using?
The picture of the box shows a round driver the other a 'sqound' one ( Round with squared shoulders/corners)
The one labelled "Kenwood" looks like an Elac/KEF/Vifa driver, a lot of manufacturers used that squared off frame.
The box itself looks OK and if you'e already tweaked the inside why not just do a pretty-up??
Is the box wood veneer or PVC/paper?? cos if it's real veneer a light sand and varnish may work in the short term

[Moondog55]

Planet 10 may be able to help with the speaker itself he has some makers data related to the serial/model # on the back of driver

[planet10]

The difference in the woofer frames had me for a bit, but there is a decorative bezel hiding the frame... the tweeter looks like a Foster imitating a Vifa,,, the woof could be from any of a number of OEMs -- any idea what vintage these are? I'm tempted to call the 743TM a date code, but 1974 is likely too old for these.

I have some Malaysian Easttechs that look similar, but then i have quitye a few similar looking drivers with unknow OEMs...

Can you post a pic of the box without the drivers?

dave