Uknown speakers (also finding specs)

Welcome To

Uknown speakers (also finding specs)

This topic is empty.

Viewing 9 posts - 1 through 9 (of 9 total)

Author

Posts
April 27, 2010 at 5:43 pm

#696434
1

Fokwise

@fokwise

Member
Hi all, I have a pair of mid range speakers, which were put together 10 or 20 years ago I think by a man who owned a music shop.

He replaced the cabinets and added a Motorola tweeter to each one.

I recently wanted to know what kind of specifications the speakers had, so that I could use them, knowing their limits and not damaging them.

After removing the driver from the cab of one of the speakers, i found the following details stamped on it:

T208 [Large black print on the back of the driver]
T2089 [On part of the metal side of the driver]
L616V [Near to the previous part of writing]

and also BB1 in a circle about 15mm in diameter stamped on a different part of the metal on the side of the driver.

My dad who bought these originally from the chap at the music shop reckonned that they were 150 watts each (I’m unsure as to whether he is correct or not). Each driver measures 30cm in diameter.

I would like to know the wattage of them, and i had a theory for finding this out which i would like to have an informed opinion on: If i put a 0db signal through a comparitively large amplifier (I am currently saving for something imbetween 1-4Kw, I’m not sure what to go for as I want to keep in mind increasing my system in the future), into my speakers, starting at no volume, then slowly increasing until just before distortion kicks in (using the kind of music i would be playing most of the time) then looking at the fraction of the volume dial on the amplifier being used and then using division of the max power output of the amp to figure out the max input to my two speakers. Would this be a decent representation of the max power my speakers could take?

To sum up:

Any ideas what my drivers might be?

would my theory for measuring speaker capacity work well?

Some advice on amps (any amps i should look out for? what size do you think i should have?) would be handy too, I’m wanting to use my equipment for fairly large parties (as my system grows, so to does the size of the party, well thats the plan anway…).

Cheers
April 27, 2010 at 8:39 pm

#934357
1

joshd96320

@joshd96320

Member
hmm, is there any brands on the driver?

no, you cant work it out from that sorry… you need either complicated equipment, or the spec.

amps: check my other post in the other thread. but btw, you cant get a massive “4kw” amp to power a 150w speaker, as the 150w speaker will just blow up
April 27, 2010 at 8:47 pm

#934354
6

General Lighting

@general-lighting

Moderator
Staff
from the description, I would say the speakers are indeed about 100-150W and the sort of unbranded Taiwanese drivers what were sold in music/electronic shops back then. They would have been sold alongside a similarly rated power amp. I wouldn’t put any more power than about 100-150W down them and expect them to survive!
April 27, 2010 at 9:04 pm

#934360
1

Fokwise

@fokwise

Member
I realise that i can’t use the FULL power of an amp which is massively inproportianate to my speakers. But surely i can use a very small amount of the total power, thus only pushing the speakers to their limit?
Any idea what sort of impedance the pair of these might have?
April 27, 2010 at 9:12 pm

#934358
1

joshd96320

@joshd96320

Member
yeah you are right, its just very difficult to judge how much is too much, and you always get some twat what turns up all the knobs as far as he can.
probably 4 ohms… maybe 2, it depends how they are wired (parrallell vs series), although thinking about it i think some older speakers were 6-16ohm. somebody older might have a better idea answering that 1
April 28, 2010 at 2:50 am

#934355
1

noname

@noname

Member
@Fokwise 381695 wrote:

Hi all, I have a pair of mid range speakers, which were put together 10 or 20 years ago I think by a man who owned a music shop.
He replaced the cabinets and added a Motorola tweeter to each one.
I recently wanted to know what kind of specifications the speakers had, so that I could use them, knowing their limits and not damaging them.
After removing the driver from the cab of one of the speakers, i found the following details stamped on it:
T208 [Large black print on the back of the driver]
T2089 [On part of the metal side of the driver]
L616V [Near to the previous part of writing]
and also BB1 in a circle about 15mm in diameter stamped on a different part of the metal on the side of the driver.
My dad who bought these originally from the chap at the music shop reckonned that they were 150 watts each (I’m unsure as to whether he is correct or not). Each driver measures 30cm in diameter.

T2089 is the code on a Celestion G12H if it’s stamped on the basket (a 12″ speaker which is the same as 30cm) – generally used as a guitar speaker, so it could be an original one of those (celestion have done an anniversary remake as it’s a classic guitar speaker). The L616V would then be a date code (couldn’t tell you what date it is though, as the ones I’ve seen are all 4 digit codes).

If so, it’s only 30W RMS. Not 100% sure from the detail you’ve given (a photo or two might help), but it’s the only thing any of those codes brought to mind…
April 28, 2010 at 3:21 pm

#934361
1

Fokwise

@fokwise

Member
Wow thanks, thats some great knowledge you’ve got there :L might be fairly likely, as the music shop they came from was mainly sort of guitars and drums. Could anyone explain the different ways wattage is shown (RMS etc…)? Sorry, i’m a bit of a newbie :L
April 28, 2010 at 3:24 pm

#934359
1

joshd96320

@joshd96320

Member
@Fokwise 381778 wrote:

Wow thanks, thats some great knowledge you’ve got there :L might be fairly likely, as the music shop they came from was mainly sort of guitars and drums. Could anyone explain the different ways wattage is shown (RMS etc…)? Sorry, i’m a bit of a newbie :L

basically, all the others except RMS are a fantasy and the manufacturer will bump it as high as they want. for example “50,000w” when the actual RMS is 50w.

only pay attention to RMS, in basic terms 🙂

noname probably has a better explanation, but thats the rule i go by.
May 1, 2010 at 1:09 am

#934356
1

noname

@noname

Member
@joshd96320 381781 wrote:

basically, all the others except RMS are a fantasy and the manufacturer will bump it as high as they want. for example “50,000w” when the actual RMS is 50w.

only pay attention to RMS, in basic terms 🙂

noname probably has a better explanation, but thats the rule i go by.

Pretty much good advice – pro kit also gives a “program” rating which is useful as the difference between the RMS and program ratings give you a range of powers to drive speakers at (RMS means Root Mean Square, and is a statistical method using a quadratic mean calculation on a selection of power measurements sampled, usually when applying a continuous sine to a specified speaker load (ie it will say 300W RMS at 8ohm meaning 300Watts when driving an 8ohm speaker impedance load) – basically it equates to an average power that the equipment is designed to either produce or work from).

Many manufacturers basically double the RMS rating for their program ratings, so look out for that as it means the program rating is less useful – to do it properly they need to do the statistical calculation on program (meaning music) source material (and preferrably a wide selection of program sources).

Another standard often specified is the AES rating – basically a similar statistical calculation but using pink noise as a source which then gets band and peak limited in various ways. This rating is also useful (if there is no program rating then this will give you the other part of a range of power in the same way the program rating will).

If you want to know more about the various ratings Peavey have an excellent article in their technotes section of their site here.
Author

Posts

Viewing 9 posts - 1 through 9 (of 9 total)

You must be logged in to reply to this topic.