Maplins close-out on AP100Z0

[daatkins]

The are great little drivers! I use them in my computer speakers (around 3 liters sealed, active XO at 120Hz). They have good detail resolution and easy to work with, too.

I bought two (for £15 each - humph!) and the TS parameters I measured, using SpeakerWorkshop, were not too close to what Audax specify. I never determined if this due to my measurement error, a SW software error or Audax manufacturing error! Some details:
T/S measurements with Speaker Workshop

Nice one,
David.

[5th element]

Well if its any help the simple MT that ive got goes loud enough anyway and punches lowish too. So there is no reason really to worry, an MTM.5 or MTM MM threeway would go quite loud anyway.

Yes I think that a sealed box would be a good idea for the MTM and then ported for the .5MM bit. So whatever happens or you decide to go with im sure it will be sellable. Small footprint = high SAF, lots of drivers = high male wanting factor they look impressive. And if you do a good job on the xover and finish hopefully you could make a few bob.

Ill still post the design of mine when its completed if anyone wants any ideas.

[5th element]

Well if we are doing pictures heres mine

[SimontY]

Great pictures you two!

When I get round to knocking something up it won't look anything like those, lol

I agree that lots of drivers = desirable -it certainly does for me!

I wouldn't be selling such a project for profit btw, just to cover the costs or thereabouts, and not enough of my friends have very high fidelity kit, so I need to help them maybe! I'll be making a set of speakers with these purely for learning and fun.

I look forward to seeing your design 5th, particularly as I have no measurement equipment, and would be trusting to luck a little bit in the x-over design (but that's part of the fun!)

[daatkins]

Nice work Mr Element!

I originally planned to use that tweeter (actually the version with the truncated faceplate). I proceded to design and build the box only to find that... Maplin had discontinued it! The round facelate version was slightly too large so I re-used the 10mm dome tweets from another project. It means I have to run the AP100Z0 fairly high but the result is still quite impressive.

simontY:

I have no measurement equipment

I use SW for all my speaker tweaking needs. The box underneath the speaker in my pic is the mic preamp/power amp. Cost about £20 to make, and the software is free.

Nice one,
David.

[Cal Weldon]

Originally posted by SimontY
When I get round to knocking something up

Hi SimontY,

I'm not sure what that means in your country, but here in North America, I can assure it doesn't mean build something.

Cal

[SimontY]

Originally posted by daatkins

I use SW for all my speaker tweaking needs. The box underneath the speaker in my pic is the mic preamp/power amp. Cost about £20 to make, and the software is free.

I know this is a bit side-tracked, but how does that work out so darned cheap? And what do you use for a mic.? We just bought a £30 (handy Maplins again!) Prosound vocal mic., which does include a FR graph in the box - could I use that? And with the crappy £25 Maplins preamp I bought?

[SimontY]

Originally posted by Cal Weldon


Hi SimontY,

I'm not sure what that means in your country, but here in North America, I can assure it doesn't mean build something.

Cal

hehehehe, it kinda means two things over here

[daatkins]

You can use any mic for measurements but obviously your results will vary according to the mic response. I use a calibrated Panasonic mic that I imported from the USA for $20 but Vikesh did a bulk buy of uncalibrated Panasonic units a couple of months ago and sold them here for £3 each. Although uncalibrated, they're flat to around 10KHz and have a slight (around 2dB) hump around 12-15KHz - perfectly okay!

The box in my pic just contains a small gainclone to power the speaker under test, a single opamp mic preamp and a signal switching - that's all. The signal switching is based on Eric Wallin's jig:
http://www.gti.net/wallin/audio/jig2/jig2.html

Nice one,
David.

[5th element]

A mic preamp is a mic preamp as far as im concerned, aslong as the preamp doesnt alter the frequency response in anyway it'l be fine to use.

The mic also should be OK because you have a frequency response graph with it. What would be even better is if you could get a copy of the graph into the computer either via a scanner or taking a good pic with a digital camera. Then you could use SPL trace and create a calibration file for the mic. The only problem I can see is that you would have to invert the frequency reponse. For instance if there was a peak in the response, in the calibration file you would need a dip to get rid of it, simply copying the freq resp wont do as it will add peak in the mic to peak in the calib file and youll be super peak!

You will still need to make the wallin jig but if you do this with budget in mind (no gold plated phonos!) then you can do it without speding too much money.

Having the ability to measure things makes all the difference when making speakers