Celestion 10-inch efficiency

[sws1]

I have 2 original Celestion 10-inch speakers in my 18-watt 2x10. Something wasn't sounding right, or as loud as I thought. So I connected the amp to the speakers in my Dr. Z MAZ 18 Jnr 2x10. Those speakers are custom built by Dr. Z. (I believe part of the speaker is a Celestion, but not sure.)

The 18-watt was now SIGNIFICANTLY louder. I'm aware that some speakers are more efficient, but with the Z speakers, the amp was as loud on 2 or 3 as the original celestions were on 10. And they certainly sounded a hell of lot better.

Could the originals be THAT inefficient? Could the magnets have gone weak? Is this a sign that the speakers are blown? Incidentally, both of the original 2x10s have the same volume (which is low). In either of these cases, can they be repaired if something is wrong?

Does anyone have any stats on the original 10-inch speakers? I've seen writing that they were 10-watt speakers. I've seen some other opinions as well.

[sws1]

I measured the DC resistance of the combined pair of speakers. (2 16-ohm speakers). The total resistance was 8.3 ohms.

Incidentally, what would a blown speaker sound like? Any sound at all?

1-last point: if 1 speaker was bad or weak, would the volume coming out of each speaker be the same? In other words, is power or volume disapated equally across a good speaker and a bad speaker?

[LeeM]

A truly blown speaker will have no sound and infinite DC resistance. I once had a speaker on the verge of failure that measured less than 2 ohms. It was in parallel with an identical speaker and the amp volume was drastically lower. Try posting in your info in the speakers section of Weber's board. You'll have more experts to help you out. It's possible that those are just very inefficient speakers.

[Plexi]

Well, i've smoked about 3 test speakers on my work bench.. So i can say they may read ok with a meter..but be somewhat locked up..they lose volume when the speaker can't move. Usually you may hear a rub..but sometimes not. they just kinda freeze up..hey thats a good one.. freeze up from being overheated.. Should of said lock up... I usually use cheapo speakers for my test bench,cause i hate to fry expensive ones. It happens,you can't use a load resistor all the time... I would say since you already tried some other speakers..and they worked alot better.. your speakers may need rebuilt..

Richie

[sws1]

Thanks. I'll give that try.

I also spoke with Ted Weber. He said that they are able to test the speakers for a variety of things, including demagnetized magnets (although he doesn't think that's the problem, since ceramics don't typically do that.) So, I'll probably ship the speakers to Weber to analyze and hopefully correct.

[SpentMusic]

FWIW

I've made a number of cabinets with the now discontinued Vintage 10. The speaker has a rating of 97dB 1W@1m/80Hz. That is low compared to a number of other Celestion speakers that come in at 99 or 100dB. There is a noticable difference between 97 and 100dB.

I've done a comparison between the Vintage 10's and the Blue Pups from Ted Weber. I can only say they were both loud. I don't know the rating of the Blue Pups.

When I tested a Greenback G12M (97dB) and a G12h30 (100dB) you could tell the difference in volume.

Jeff Swanson
SpentMusic, Inc,
www.swansoncabinets.com