Replacing 6 ohm speaker cone w/ 8 ohm cone

Nedtalk · June 23rd, 2009, 03:51 PM

Hello. I have 2 old ESS (circa 1977) box speakers with cones that are blown. Originally the speakers contained 6 ohm woofers, 8 " large. There are no 6 ohm woofers the sale anywhere that I could find. I was advised by someone to just get 8 ohm cones and pop them in where the 6 ohms used to be.
Is this Ok to do? There are lots of 8 ohm cones available and I would do this if I didn't have problems. And there is a 6 ohm tweeter on those boxes as well. Would I have a problem mixing 6 ohm tweeters and then new 8 ohm woofers in the same box?
Thank you for your help.

**Whir** · June 23rd, 2009, 04:38 PM

Nope. It'll change the overall impedance of the enclosure a little bit, but it won't affect any kind of modern (ie post 70s) amplifier. The tweeter may suck up a little more juice due to the low impedance, I've forgotten how mixed systems work, so I would recommend finding a high sensitivity driver for the woofer. Anything current should have better sensitivity than something made in the 70s.

Out of curiousity, did you check parts express? If I recall correctly, they had 6ohm drivers the last time I was there.

**RobRich** · June 23rd, 2009, 05:33 PM

If wired in series:

8 + 6 = 14 ohms

If wired in parallel:

(8 x 6) / (8 + 6) = 48 / 14 = ~3.43 ohms

At what impedance is your amp rated?

Nedtalk · June 24th, 2009, 12:14 PM

It is an 100W x 5, looks like 8 ohm amp. If I buy all new 8 ohm cones for this old 6 ohm speaker box, what are those 2 coiled units attached to the inside of the speaker? Don't I have to upgrade those too?

**RobRich** · June 24th, 2009, 12:45 PM

8 ohms is typical for a residential configuration. The existing 6-ohms speakers should be in a series at 12 ohms. Completely going to 8-ohms speakers is going to put each affected channel up to 16 ohms, which should still work, but expect a mild drop off in sensitivity and maximum SPL (volume). As Whir suggested, opt for speakers with high sensitivity to help offset the difference.

About the "coiled units" in the enclosures, I suppose you could mean crossovers if wired between the posts and speakers. Got a picture?

Nedtalk · June 24th, 2009, 01:59 PM

2 actual speakers and one passive radiator ( not a real speaker at all - just a foam flap the resounds bass near a wall. Rather unique at the time.)

Please title this page. (Page 1)

Nedtalk · June 25th, 2009, 12:54 PM

Sorry the link title is "Please title this page", but if you click on it, you'll see the coiled units.... I guess they are matched to 6 ohms and I should get a new one. Any advice on which one to get?

**RobRich** · June 25th, 2009, 01:26 PM

That is a crossover network. If the capacitors look okay (no leakage or spotting), then it is likely in working condition. Just wire the new speakers exactly like the old ones.

Nedtalk · June 25th, 2009, 08:07 PM

Thanks for all your help..

Brainchild · June 26th, 2009, 03:25 AM

Quote:

Originally Posted by RobRich

If wired in series:

8 + 6 = 14 ohms

If wired in parallel:

(8 x 6) / (8 + 6) = 48 / 14 = ~3.43 ohms

At what impedance is your amp rated?

It only affect the OHM rating if the speakers are wired together before the crossover. I have 2 16 OHM speakers wired at 8 OHM with an 8 OHM horn speakers on one section of the crossover and the horn on the other and it's still 8 OHM at the connection,only the two speakers wired before the crossover are affected.A different set of speakers I have an 8 ohm speaker and an 8 ohm horn wired to the crossover and the total impedance is only 8 ohm. Of course I'm talking about loudspeakers but the principal is the same I'm sure.

But yeah wire it up it'll work fine.