(new to HiFi) Have I wired these correctly?

iostream · 21 Jul 2019 at 15:45

Hi folks,

I decided to take my first steps into a bit of hifi audio. I'm getting made redundant next month so I'm wasting money instead of saving

Figured I'll have some downtime while I hunt for the next job and it would be nice to relax to some music.

I've picked up an old stereo valve amplifier (Dynavox VR-70E) and a pair of Mission M35 floor standing speakers. I have an Audioengine D1 DAC in a cupboard being unused, so the plan is to have it feed the amp via a laptop which is where the music will live. I've purchased a few meters of QED Micro speaker cable, it was getting good reviews and was cheap.

All was well until I looked at the back of the speakers and I got a bit confused:

The previous owner had these little wires in the photo above, one connected to both black terminals and one connected to both red terminals.

Did some quick Googling and I understand now that four terminals on a single speaker are for the purposes of bi-wiring which may (or may not) improve audio quality.

However the back of my amp looks like this:

I've gone for the 8 ohm option instead of 4 ohm simply because the back of the speakers say "8 ohms compatible". I assume this is correct?

Anyways my main question was, am I ok to wire each of speakers like this:

Thanks in advance!

iostream · 21 Jul 2019 at 15:52

PS a couple follow up questions

- I'm assuming I can't bi wire as my amp doesn't have four output terminals per speaker?
- I'm assuming the bridge between the LF and HF (little black cable) is required as otherwise only a part of the speaker will work?

Marsman · 21 Jul 2019 at 23:00

Looks correct to me; as long as you have black to black and red to red. I'm sure you already know that though.

iostream said:
- I'm assuming I can't bi wire as my amp doesn't have four output terminals per speaker?

No. you'd need an amplifier with two sets of speaker outputs. In any case; whether bi-wiring brings any improvement is debatable. Opinions will depend on who you talk to. Some will say it's worth it, some will say there is little to no improvement. Bi-amping though; that can bring improvements, but as you might have guessed, you'd need two amplifiers. If you were to consider that you'd need two identical amps though. Bi-amping with two different amps would be worse than just using the one amp.

iostream said:
- I'm assuming the bridge between the LF and HF (little black cable) is required as otherwise only a part of the speaker will work?

Yeah. Without those little black cables, only the driver that speaker cable is connected to would work. If you were bi-wiring, you'd remove those and run another set of speaker cables from the amplifier's second set of speaker terminals. Any such amp would need to be able to send audio to both sets simultaneously though. With some amps that have two sets of terminals, you can only select one or the other.

iostream · 22 Jul 2019 at 10:04

Great, thanks for the replies - I'll get it all wired up and tested tonight. A single wire and single amp will do me, just wanted to make sure I had it correct.
And yes, black to black and red to red

Although a bit fiddly with the QED Micro cable, as it doesn't seem to be marked in any way. I just traced my finger along the side I put in red and made sure it was plugged into red at the other end as well.

Marsman · 22 Jul 2019 at 10:59

I don't really understand it when manufacturers put no indication on to differentiate between the two wires. With some it's more subtle than others, so whether there's any at all on QED micro, I don't know. If there isn't, it would be a right pain in the butt for longer runs without a multimeter.

iostream · 23 Jul 2019 at 10:34

Upon closer inspection, turns out there's a very (very) small ridge along one wire. Anyways all sorted now, I am pleased

Thanks again for the help.

Marsman · 23 Jul 2019 at 22:13

Glad it's working. Looks good and hopefully sounds good too.

Minstadave · 23 Jul 2019 at 22:15

You're meant to keep the cables the same length too iirc. Although that maybe pseudo science!

JasonM · 24 Jul 2019 at 01:32

iostream said:
Upon closer inspection, turns out there's a very (very) small ridge along one wire. Anyways all sorted now, I am pleased
Thanks again for the help.

You need to position the speakers away from those drawers, the reason is they will restrict bass. You will end up with a sound where the high's remain ok, but the mids and bottom end is muddy. Also I presume those speakers are rear ported, so also you need them from the wall.

Also something else. That speaker will vibrate the drawers, that in-turn will vibrate the valve amp effecting the performance, you need to isolate the amp with some foam or something.

And yes speaker cable should be the same length, speaker cable is a resister and different lengths and types effect sound.

iostream · 24 Jul 2019 at 09:11

Thanks for all the advice. Yep the speakers are rear ported, I'll move them about (and further from the drawers) to experiment with the sound.

Shall see if I can find a small foam pad for the amp to sit on, although I won't be listening at high volumes so not sure how much the vibrations will come in to play.

And never considered that the speaker cable length should be the same for each speaker. I've got a ~2m run to the one in the photo above and ~6m-7m to the second speaker currently.

iostream · 24 Jul 2019 at 09:50

iostream said:
And never considered that the speaker cable length should be the same for each speaker. I've got a ~2m run to the one in the photo above and ~6m-7m to the second speaker currently.

Although now that I think about it, electricity travels at tremendous speeds through wire - almost the speed of light. I suspect the cable lengths would need to be wildly different before this comes a factor. But I'm not here to spark debate

Marsman · 24 Jul 2019 at 10:07

You can have one cable quite a bit longer than the other. As you've said, it travels so fast, it would be imperceptible. One cable would have to be ridiculously longer than the other for any delay to be noticed.

Good advice from Jason about the speaker placement. I didn't really think about that at the time when posting before.

iostream · 24 Jul 2019 at 10:36

I've ordered 8x "Fisual Round Adhesive Isolation Pads" to put under the speakers, should get rid of any unwanted vibrations hopefully. I'll have some time this weekend to test speaker placement. Exciting times

JasonM · 24 Jul 2019 at 12:42

iostream said:
Although now that I think about it, electricity travels at tremendous speeds through wire - almost the speed of light. I suspect the cable lengths would need to be wildly different before this comes a factor. But I'm not here to spark debate

It's not the speed of electricity, it's more that cable is a resister. As the cable length increases the resistance increases and this effects sound, the first thing to notice will be more restricted bottom frequencies. 2m one side and 6+m the other is quite a lot. If you were to position speakers so listening position is in perfect triangle you should notice that difference. On the plus side it appears you have used pretty thick speaker cable and will reduce the difference (compared to mismatched length thinner cable), however there will still be an unbalance between left and right speakers.

iostream said:
I've ordered 8x "Fisual Round Adhesive Isolation Pads" to put under the speakers, should get rid of any unwanted vibrations hopefully. I'll have some time this weekend to test speaker placement. Exciting times

The sound is not just coming from the speaker drivers, but also from the speaker cabinet, namely some lower frequencies are travelling via the cabinet. Because of this you need space around the speaker so sound can fill the room correctly.

iostream · 24 Jul 2019 at 16:10

Thanks Jason, certainly interesting. I'll try and see if I can hear any difference. If so I'll know to try extending the 2m cable to 6m

JasonM · 24 Jul 2019 at 17:06

iostream said:
Thanks Jason, certainly interesting. I'll try and see if I can hear any difference. If so I'll know to try extending the 2m cable to 6m

Extended cable is possibly worse then having the mismatched lengths, as the join is a point of resistance.

In a perfect world you need a new run of matched cable.

DCSK cable from the rain forest site is what I run and it's really good.

Rroff · 24 Jul 2019 at 17:14

JasonM said:
It's not the speed of electricity, it's more that cable is a resister. As the cable length increases the resistance increases and this effects sound, the first thing to notice will be more restricted bottom frequencies. 2m one side and 6+m the other is quite a lot. If you were to position speakers so listening position is in perfect triangle you should notice that difference. On the plus side it appears you have used pretty thick speaker cable and will reduce the difference (compared to mismatched length thinner cable), however there will still be an unbalance between left and right speakers.

I might be wrong but I'd imagine there will be quite a bit of difference in terms of things like Johnson-Nyquist noise even on a few metres of different cable length which might affect SNR, etc. enough for the distortion to be noticeable as an imbalance.

JasonM · 24 Jul 2019 at 19:00

Rroff said:
I might be wrong but I'd imagine there will be quite a bit of difference in terms of things like Johnson-Nyquist noise even on a few metres of different cable length which might affect SNR, etc. enough for the distortion to be noticeable as an imbalance.

I've never noticed interference from actual speaker cables, not in a domestic/home setup anyway, but as you say it will non the less be present.

I have however noticed audio differences from speaker cables, i'm not necessary talking about premium cable either. In my home office setup, I changed the supplied speaker cable to some thicker pure copper Maplins cable (think it was £4 in closing down sale) and the thicker cable improved the sound. One test is to just change one channel, then switch the left/right balance and providing the rest of the system has the resolution, you should hear the differences in the cable.

Rroff · 24 Jul 2019 at 19:06

JasonM said:
I have however noticed audio differences from speaker cables, i'm not necessary talking about premium cable either. In my home office setup, I changed the supplied speaker cable to some thicker pure copper Maplins cable (think it was £4 in closing down sale) and the thicker cable improved the sound. One test is to just change one channel, then switch the left/right balance and providing the rest of the system has the resolution, you should hear the differences in the cable.

If that is the case I'd imagine the actual problem might be the amplifier being sensitive to capacitive loading or similar and the thicker cable having a better dielectric and/or lower resistance.

I know with my HD600s which have a long standard cable some amplifiers have problems with the capacitance and sound dull with them.

JasonM · 24 Jul 2019 at 21:51

Rroff said:
If that is the case I'd imagine the actual problem might be the amplifier being sensitive to capacitive loading or similar and the thicker cable having a better dielectric and/or lower resistance.

I know with my HD600s which have a long standard cable some amplifiers have problems with the capacitance and sound dull with them.

I've noticed the same effect on 2 systems, the one in my home office, and also my Pioneer separates into Yamaha speakers down stairs. My Pioneer separates I was using some 1.5mm cable that came with the speakers, then moved to 4mm DSCK cable, however in fairness 2.5mm pure copper would be been enough I expect.

PS Audio mentions speaker cables here.

https://www.youtube.com/watch?v=u9wGoQ2KGkU