* The DIY Audio Thread *

Tr Insanity · 9 Jan 2010 at 17:06

DiG said:
Hi, just made some speaker cable out of Cat5 (easy I know, buy I'm just starting out!)

They sound good but the bass seems to be very weak, it can still get down as low as it did before, but at a much lower volume

What have I done wrong?

Thanks

Not an expert by any means but it may help if you state the rest of your equipment

If you just used a single strand of cat for each channel & ground , that could be the problem as the wire is too thin which may effect bass.

I'm sure someone else will give you a better answer , but this may help

Also , I've looked at the suppliers posted further up the page and they're components aren't exactly cheap ! So if I'm looking to build a cheap CMoy , where should I buy the components from ? Thanks

MikeHunt79 · 9 Jan 2010 at 17:07

DiG said:
What have I done wrong?

You've used cat 5!

It could be the capacitance of the cable killing the bass, or more likely it could be the fact that cat 5 is not really intended for large amounts of current.

How many strands are you using and so you know the AWG rating or thickness of each strand? You can always add in more stands if you don't mind using a bulky cable.

DiG · 9 Jan 2010 at 17:51

I'm using 3 strands braided together, its 0.52 plain copper strands.

Is this not enough? I thought about using more but the 18 meters cost me £20 already!
Thanks for the replies

EDIT: I'm using a Yamaha AX-396 amp and Castle Kendall II speakers if this helps

Dr.EM · 9 Jan 2010 at 17:59

Be certain you haven't wired the speakers out of phase with each other when installing the new cable! I can't see the cable making such a noticeble difference otherwise, even though it is thin cable to use for speakers and apparently a long run.

Kol · 9 Jan 2010 at 18:02

DiG said:
I'm using 3 strands braided together, its 0.52 plain copper strands.

Is this not enough? I thought about using more but the 18 meters cost me £20 already!
Thanks for the replies

EDIT: I'm using a Yamaha AX-396 amp and Castle Kendall II speakers if this helps

A good idea is to take a look on the bay, you can get ~100m reel/roll for about £24 which should enable you to make a larger braid using more strands.

MikeHunt79 · 9 Jan 2010 at 18:37

People pay for cat5?

I think one of the big reasons cat5 is popular for with DIY'ers is the fact is can be had very cheaply or often for free. I would go with more strands personally, maybe 9 per connection. As Dr. EM said, check for phase. If they are out of phase, the cones will move a lot but it won't sound very bassy...

Finally, how far are your speakers from the amp? Short runs should have less issues.

DiG · 9 Jan 2010 at 19:06

Just to double check, by stands you mean lengths of cable? If you mean strands as individual cables then its actually 12 per terminal, so 24 per cable.

I just went to ******, didn't even think to check the bay! I presume by out of phase you mean - connected to a +? I was quite careful to avoid this but I will check when I'm home

Thanks

DiG · 10 Jan 2010 at 19:21

Just checked, and its all connected up properly. Shame because the cables made a significant different otherwise!

Yamahahahahaha · 10 Jan 2010 at 20:05

You're better off just getting a decent gauge of speaker wire. 3 core power cable is suitable.

Cat5 is less than optimal for speaker cable because each pair has a different number of turns. More turns = greater length.
Effectively you've got signals all leaving at the same time, and arriving at different times (we're talking fractions of a second, but it would influence the sound). Added to this, very low gauge and field effects with more power being used than Cat5 spec.

Anyway, it's just a hobby.

samcat · 10 Jan 2010 at 20:17

Just finished putting together a redesigned cmoy, using a TLE2426Cp voltage divider chip... Made a noticible difference to the sound, for the better.

Put together a diagram for it (after building it) which I am 99% sure is correct:

LED can be offboard, as can its resistor

DiG · 11 Jan 2010 at 13:10

Yamahahahahaha said:
Cat5 is less than optimal for speaker cable because each pair has a different number of turns. More turns = greater length.
Effectively you've got signals all leaving at the same time, and arriving at different times (we're talking fractions of a second, but it would influence the sound).

Really? Wouldn't the difference in length be at most, mm's? Not saying your wrong, just would have though you would need a much bigger difference in length, more like a few meters, before you got even fractions of a second's difference?

p4radox · 11 Jan 2010 at 13:19

DiG said:
Really? Wouldn't the difference in length be at most, mm's? Not saying your wrong, just would have though you would need a much bigger difference in length, more like a few meters, before you got even fractions of a second's difference?

I agree.

I think the difference in length is more likely to affect the series inductance/shunt capacitace of the cable which will introduce a low pass filter effect and mute the highs. It could also introduce a significant phase shift.

Dr.EM · 11 Jan 2010 at 13:31

My reccomendation for speaker cable:

http://www.studiospares.com/Cable-Speaker-/Speaker-Cable-2X25mm/invt/548320

Good no-nonsense cable. Bit more flexible than a mains cable, easy to prepare, quite discrete. Out of stock apparently, but it'll be back I'm sure

DiG · 11 Jan 2010 at 14:14

What tests could I do with a multimeter to see whats wrong with my newly made cable?
Thanks

p4radox · 11 Jan 2010 at 15:09

DiG said:
What tests could I do with a multimeter to see whats wrong with my newly made cable?
Thanks

A simple one would be to just check the resistance. Use the highest sensitivity as it's unlikely to be more than one ohm.

DiG · 11 Jan 2010 at 16:55

Just checked, and I've got the following
L
+ 0.3
- 0.3
R
+0.3
- 0.3-0.4

Is this good or bad?

MikeHunt79 · 11 Jan 2010 at 16:55

Dr.EM said:
My reccomendation for speaker cable:

http://www.studiospares.com/Cable-Speaker-/Speaker-Cable-2X25mm/invt/548320

Good no-nonsense cable. Bit more flexible than a mains cable, easy to prepare, quite discrete. Out of stock apparently, but it'll be back I'm sure

That's a good price for some nice cable. Everywhere else seems for charge more than £1 a metre for 2.5mm CSA stuff.

Tr Insanity · 11 Jan 2010 at 18:38

DiG said:
Just checked, and I've got the following
L
+ 0.3
- 0.3
R
+0.3
- 0.3-0.4

Is this good or bad?

I assume consistency is good

gurusan · 19 Jan 2010 at 21:51

I have just soldered together the grubDAC, but I bridged 2 pins on the PCM2706 DAC and can't seem to get it right! Any tips?

I have purchased some .8mm solder braid and a new solder tip as mine is crapola but those won't be here for a day or 2.

Anyway it looks awesome lol, soooo tiny. I just wish I could fix this solder bridge!

86JR · 19 Jan 2010 at 21:53

Hoping to build some IPL transmission lines later this year, or possibly pay someone to design some for me. Want to use a scan speak tweeter, this one. Its closed back so can put in any enclosure and it wont affect the sound.

Ideally want to use car audio as they are 4 ohms so will get the most out of amp!

https://www.wilmslow-audio.co.uk/catalog/product_info.php?cPath=22_35_178&products_id=179

in car audio land, known as Genesis R1's.

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