4 ohm speakers?

All things NVA
MarcoPisa
Posts: 28
Joined: Thu Dec 28, 2017 8:54 am
Has thanked: 0
Been thanked: 3 times

4 ohm speakers?

Unread post by MarcoPisa »

Good evening guys, my friend asked me to try my AP20 on his Kef speakers. Kef impedence is 4 ohm. I don't remember if our ampli is designed to work with 4 ohm speakers. I am ising NVA speaker cables.
kef 103/4 reference from the 90's.
Thanks in advance

User avatar
savvypaul
Posts: 8635
Joined: Tue Oct 11, 2016 7:14 pm
Location: Durham
Has thanked: 1657 times
Been thanked: 2978 times
Contact:
Great Britain

Re: 4 ohm speakers?

Unread post by savvypaul »

It depends on the shape of the curve - how long it is down around that number, and at what frequencies.

Can you post the plot for it?
I am in the hi-fi trade
Status: Manufacturer
Company Name: NVA Hi-Fi
https://nvahifi.co.uk/

User avatar
karatestu
Posts: 5945
Joined: Sun Jan 08, 2017 4:40 pm
Location: North Yorkshire
Has thanked: 1865 times
Been thanked: 1378 times
Great Britain

Re: 4 ohm speakers?

Unread post by karatestu »

If that 4 ohms is the nominal figure quoted by the manufacturer then it is likely to dip even lower than 4 ohms.
DIY FREE ZONE

User avatar
savvypaul
Posts: 8635
Joined: Tue Oct 11, 2016 7:14 pm
Location: Durham
Has thanked: 1657 times
Been thanked: 2978 times
Contact:
Great Britain

Re: 4 ohm speakers?

Unread post by savvypaul »

karatestu wrote: Wed Sep 30, 2020 4:18 pm If that 4 ohms is the nominal figure quoted by the manufacturer then it is likely to dip even lower than 4 ohms.
Yes, but if it is in the high frequencies it will be benign to NVA amps. If it is in the low frequencies, the NVA amps will not like it.
I am in the hi-fi trade
Status: Manufacturer
Company Name: NVA Hi-Fi
https://nvahifi.co.uk/

MarcoPisa
Posts: 28
Joined: Thu Dec 28, 2017 8:54 am
Has thanked: 0
Been thanked: 3 times

Re: 4 ohm speakers?

Unread post by MarcoPisa »


User avatar
savvypaul
Posts: 8635
Joined: Tue Oct 11, 2016 7:14 pm
Location: Durham
Has thanked: 1657 times
Been thanked: 2978 times
Contact:
Great Britain

Re: 4 ohm speakers?

Unread post by savvypaul »

Required power: 50 to 200 watts.

The AP20 is around 35 watts.

Complex looking crossover.

Not what NVA is designed for.
I am in the hi-fi trade
Status: Manufacturer
Company Name: NVA Hi-Fi
https://nvahifi.co.uk/

MarcoPisa
Posts: 28
Joined: Thu Dec 28, 2017 8:54 am
Has thanked: 0
Been thanked: 3 times

Re: 4 ohm speakers?

Unread post by MarcoPisa »

Thanks a lot. Do I risk to spoil the ampli if I test it with those speakers?

User avatar
savvypaul
Posts: 8635
Joined: Tue Oct 11, 2016 7:14 pm
Location: Durham
Has thanked: 1657 times
Been thanked: 2978 times
Contact:
Great Britain

Re: 4 ohm speakers?

Unread post by savvypaul »

Keep a check on the temperature of the amp (place your hand under and along the acrylic base). NVA amps should run moderately warm, at the very most. If it is too hot to touch, it's too late.

I cannot see the AP20 being a good match for those KEFs, regardless.
I am in the hi-fi trade
Status: Manufacturer
Company Name: NVA Hi-Fi
https://nvahifi.co.uk/

MarcoPisa
Posts: 28
Joined: Thu Dec 28, 2017 8:54 am
Has thanked: 0
Been thanked: 3 times

Re: 4 ohm speakers?

Unread post by MarcoPisa »

Thanks again

User avatar
Latteman
Posts: 1220
Joined: Tue Aug 14, 2018 7:20 pm
Location: S. Yorkshire
Has thanked: 553 times
Been thanked: 297 times
Contact:
Great Britain

Re: 4 ohm speakers?

Unread post by Latteman »

Don’t risk it
Analogue Source -
Denon DP47f- Ortofon mc20 supreme
Ifi Zen Phono
Doug Self balanced Pre amp
Akai 4000DS mk2 R2R
Digital Sources- IfI stream, Ifi Neo idsd Dac; Tidal / Radio Paradise
Amplification Nva 30vdc mono blocks
Speakers Lii Audio F-15 in Open Baffle; Ls6
Weiduka AC8.8- for digital sources
Mini BMU for analog sources

Post Reply