Speaker matching ...

[jazzyjoepass]

Just curious

EVM12L is 8ohms but the circuits are 4ohms so how did HAD employ EVM12L in his 1x12" combos?

Someone enlighten me, pls. ....

[Harris]

I don't know how HAD did it, but he could have used multiple tap OT's and taken the feedback from the 4 ohm tap (I'm assuming that's what you mean when you say the "circuits are 4 ohms." It would be quite simple to use the 8 ohm tap for the speaker and the 4 ohm tap for the feedback.

You can also safely use an 8 ohm speaker with a 4 ohm tap as well. Maybe they were mismatched. The mismatch will effect tone, but not necessarily in a bad way.

[llemtt]

I think mismatching, lots of OTs used by HAD only have the 4ohm tap! and only the latest amps feature a 4-8 ohm selector.

[Bob-I]

Just curious

EVM12L is 8ohms but the circuits are 4ohms so how did HAD employ EVM12L in his 1x12" combos?

Someone enlighten me, pls. ....

a 2:1 mismatch on impedance is acceptable. I'd assume he accepted this mismatch

[dogears]

Part of the sound

I always check 8 into 4 and see how I like the tone.

[jazzyjoepass]

Thanks guys. I'm so glad to be part of this community.

I brought my amp to "show off" at a friend's local guitar shop and it caused quite a stir. We didn't have any cab, so we just plugged into a trace elliot guitar amp's 1x12" (celestion G12H-60). It was open back.

The amp clocked like 5-6hours and didn't show any sign of tiredness. At the end of the day when I was packing up, took a look at the speaker, and guess what? It was 8ohms.

By the way, I checked out the Thiele-Small parameters for the EV12L ... it seems pretty close to an 4ohm. Read somewhere that in the speaker industry, any speaker with DC resistance slightly higher than 4ohms, it would be categorised as 8ohm. I guess it just sit in between a 4 and 8ohm.

All thanks to all who shared, I've learned alot.

I love this forum, man.

[908ssp]

DC resistance is not a full reflection of a speakers impedance as that is an AC measurement. From the graphs I have seen on Aiken's site the impedance varies according to the frequency and goes as high as 50 ohms at high frequency's on a 8 ohm speaker. Anyway I just mention it because we often I think over state impedance matching like it is an absolute. In my MKIIC+ manual Randal Smith recommends trying different impedance settings to alter the tone, so he is pretty confident that his amps can handle it.