PA Speakers -- may be slightly OT...

[jeffbrown]

Forgive me if this is OT, but I figure someone here can help.

I was given some PA speakers. They are Klipsch La Scala speakers, and there are 4 of them. Two are HF, and two are LF. Since I know little about PA speakers, I'm assuming the HF are high frequency, and the LF are low freq. The HF sections are horns in enclosures, and the LF sections are roughly 2 ft square and have a large baffle-type thing viewed from the front, behind which must be the speaker. They are hell-for-rugged, too!

Each individual speaker has, on its face plate, an indication for 8 ohms. Each HF faced plate also has the following info:

Input Maximum system power: continuous program -200W; peak program -750W

There are two fuse holders; one is labeled 1.5 amp, the other, LF 3 amp fuse. (Here I assume the 1.5 amp-er is for the HF section...)

Also on there is there is: SPL @ 3 /and here the panel has been cut away, and resuming after the cut/ (10 ft) @ 1 watt input -96dB. Under that is: 400 Hz crossover - zener diode tweeter protection. There is an input jack and an output jack, the latter is for the LF section.

The LF sections have inputs for connectors from the HF sections.

I was told they used to be in a school gymnasium, and were run off a combination CD player/stereo radio.

I checked them for continuity, and each seems to be OK.

What exactly do I have, and is it worth it to find an amp (Crown, etc.?) for them? Could I indeed run them with a stereo system? If I recall, each channel, left and right, must be rated at least at the sum of all speakers' ohms rating divided by the number of speakers, i.e., 8 + 8 = 16/2 = 8, so a channel rated at 8 ohms or less would be OK.

TIA for your info, and patience!

[Alex1984]

Do they not have a jack plate that has the impedance labeled? If they do, I'd trust that label. Impedance depends on how they are wired. If they are in series, the impedance is just added up. If they are in parallel, Z total = 1 / [(1/Z1)+(1/Z2)+(1/Z3)...]. However, for two way systems with crossovers, I'm not sure how this equation'd hold up.

Have fun!

[BassmanPaul]

A picture or two is worth a thousand words of description.

Paul

[Thor]

Typically a cab set up like that daisy chained between a
HF box and a LF box has internal crossovers. Sounds like
that is set up for 400 hz.

The LF cab has a low pass crossover and the HF has a high
pass crosssover.

Simplistically, a signal at 40 hz goes into the LF box. A signal at 800 hz is in the HF box. So the unit working together
works the same way as a single cab with an internal crossover. The total impedance of the 8 ohm LF and HF boxes together is still 8 ohms. BFM once mentioned that tweeters or midranges crossed more than 2 octave higher that the fundamental don't factor into changing the impedance of a cab.

If you run it with a power amp that is mono and run both
LF/HF's it will run at a nominal 4 ohm load. Some amps are
stereo and then run each channel at 8 ohms on these.

I have heard nothing but good things about Klipsch subs.
Nice score.

[Thor]

Check here.

http://www.klipsch.com/na-en/product...a-ii-overview/

If this is them they cost 2999.00 list for each. That is a
6k system they gave you.



Nice



Hook them up to your stereo for a thrill. You will be cruising the classifieds
for power amp says my crystal ball.

[jazzblade]

Wow these are Hi-Fi speakers that they have been building since the late 50's and have continued till this day. Huge efficient Horn-loaded designs from the days when 25 watts from a Hi-Fi amp was HUGE!.

Originally designed as a PA but may be easily smoked with today's higher powered amps so watch your watts

http://www.klipsch.com/images/download/152.aspx
http://www.klipsch.com/images/download/150.aspx

Links for manuals for the series.

[Thor]

From that page:

"Capable of extreme output levels with ultra low distortion and astonishing dynamic range"

"When the La Scala first launched in 1963, audio pioneer Paul W. Klipsch made it for Arkansas gubernatorial candidate Winthrop Rockefeller to use as a public address speaker...

Despite its raw, unfinished appearance, the fully horn-loaded, three-way La Scala sounded so good people still wanted to put it in their living rooms."


Sounds like it was a PA speaker that people wanted for audiophile purposes at home. Having survived the 60's and 70's, I can tell you there was some heavy duty gear back then
Fo Sho.

[Bassmec]

Originally Posted by jeffbrown

Forgive me if this is OT, but I figure someone here can help.

I was given some PA speakers. They are Klipsch La Scala speakers, and there are 4 of them. Two are HF, and two are LF. Since I know little about PA speakers, I'm assuming the HF are high frequency, and the LF are low freq. The HF sections are horns in enclosures, and the LF sections are roughly 2 ft square and have a large baffle-type thing viewed from the front, behind which must be the speaker. They are hell-for-rugged, too!

Each individual speaker has, on its face plate, an indication for 8 ohms. Each HF faced plate also has the following info:

Input Maximum system power: continuous program -200W; peak program -750W

There are two fuse holders; one is labeled 1.5 amp, the other, LF 3 amp fuse. (Here I assume the 1.5 amp-er is for the HF section...)

Also on there is there is: SPL @ 3 /and here the panel has been cut away, and resuming after the cut/ (10 ft) @ 1 watt input -96dB. Under that is: 400 Hz crossover - zener diode tweeter protection. There is an input jack and an output jack, the latter is for the LF section.

The LF sections have inputs for connectors from the HF sections.

I was told they used to be in a school gymnasium, and were run off a combination CD player/stereo radio.

I checked them for continuity, and each seems to be OK.

What exactly do I have, and is it worth it to find an amp (Crown, etc.?) for them? Could I indeed run them with a stereo system? If I recall, each channel, left and right, must be rated at least at the sum of all speakers' ohms rating divided by the number of speakers, i.e., 8 + 8 = 16/2 = 8, so a channel rated at 8 ohms or less would be OK.

TIA for your info, and patience!

Well they are in fact hi fi or small cinema speakers normally They have been used in England as such but when the design was used by Roost it was for pa or bass guitar:

Jbl K145 bass driver and a larger midrange horn with a 2440 2" driver the top box is 6 motorola piezo super tweeters.
I tried them out on bass guitar and they sounded great so I think the original Kilipsh folded horn will too (up to a certain level).
Each Bass horn and HF horn pair is presenting 8 ohms total impedance. so to run a pair of speakers (IE Two Bass Units and Two Mid Horns properly connected to the crossovers) is a total impedance of 4 ohms:
look at an Ampeg V4B Cabinet and then look at an Acoustic 301 cabinet and you will see these designs used to be all the rage for bass players even without the midrange horn or tweeter.

[Petebass]

Originally Posted by jeffbrown

If I recall, each channel, left and right, must be rated at least at the sum of all speakers' ohms rating divided by the number of speakers, i.e., 8 + 8 = 16/2 = 8, so a channel rated at 8 ohms or less would be OK.

Don't use that formula. 2 x 8 ohm cabs is 4 ohms, not 8. There is a "rough rule of thumb" formula that only works where all cabs are of equal impedance, and that's probably the one you're thinking of:-

* impedance of 1 of those cabs, divided by the number of cabs.

So in your case 8 ohms cabs / 2 of them = 4 ohms.

[billfitzmaurice]

They are hi-fi cabs and the drivers within won't withstand the rigors of pro-sound use.

[maestrosteve]

I was just going to say what Bill just said.

Sometime around 1975, I almost bought a pair of Klipsch La Scalas for my high end stereo system. They were the model above the Klipsch Heresy, also a fine home stereo speaker. Those home hi-fi cabs cannot be treated like pro sound cabs.

I ended up with a pair of Dahlquist DQ-10 speakers, also considered high end (at that time one of the best, and I still use them) and while they still sound tremendous in a high end stereo environment, they sound like crap if I were to play an instrument thru them.

[Bassmec]

Originally Posted by maestrosteve

I was just going to say what Bill just said.

Sometime around 1975, I almost bought a pair of Klipsch La Scalas for my high end stereo system. They were the model above the Klipsch Heresy, also a fine home stereo speaker. Those home hi-fi cabs cannot be treated like pro sound cabs.

I ended up with a pair of Dahlquist DQ-10 speakers, also considered high end (at that time one of the best, and I still use them) and while they still sound tremendous in a high end stereo environment, they sound like crap if I were to play an instrument thru them.

Not much wrong with the sound of Klipsch speakers with a suitable pre amp, by the way the model: Cornwall was the model above the Heresy.
Seems to me you could improve your playing with a little practice.

[brendanbassist]

Wait.... someone.... g-gave you those? Gave them to you?!

I want some Klipsch's too!

[maestrosteve]

I remember the Cornwalls. I don't remember why I didn't consider buying them. If they were the model in between the Heresys and La Scalas, I'm thinking that my dealer didn't stock them so I never saw them or heard them.

Makes me wonder if I would have liked them, but I was a fan of Klipsch speakers during that time in the 70s. Very efficient, they would be very loud with a 100 watt amp.

[millsbass5]

Wow. If I recall,I think this is the first time I've heard this brand mentioned on here. I have 2 P.A. speakers,that I've owned since the mid-80's (15"+ horn,long throw),that grace the Klipsch name. Man,I really pushed those cabs (they didn't even flinch!).......HARD!!! As for mine?? Truly awesome, very high-quality sounding cabs. Haven't used'em in a l-o-n-g time,though.

[Bassmec]

Originally Posted by billfitzmaurice

They are hi-fi cabs and the drivers within won't withstand the rigors of pro-sound use.

I have not found the old UK made under licence la Scala type to have much in the way of problems with these drivers in them.
http://website.lineone.net/~empson/MM.html
Trouble with the USA produced ones is they used cheap drivers.
The LaScala uses a driver called the K-33. It's made for Klipsch by Eminence but I don't think it's available as a consumer product from Eminence.
I wouldn't describe an eminence driver as proffessional either Bill.
PS they are only $100 from klipsch.

[jeffbrown]

I'll try to get pix tomorrow. They don't look like the pix I've seen here. They are black, no fabric, very industrial-looking; metal corners all around. Heavy duty, road-worthy stuff.

[billfitzmaurice]

Originally Posted by Bassmec

I have not found the old UK made under licence la Scala type to have much in the way of problems with these drivers in them.
http://website.lineone.net/~empson/MM.html
Trouble with the USA produced ones is they used cheap drivers.
The LaScala uses a driver called the K-33. It's made for Klipsch by Eminence but I don't think it's available as a consumer product from Eminence.
I wouldn't describe an eminence driver as proffessional either Bill.
PS they are only $100 from klipsch.

The K33 dates back to the original Klipschorn, 60 years ago, and was originally produced by EV, as were the mid and HF drivers. All of the KHorn hi-fi variants were designed when 20 watt amplifiers were the norm.

I'll try to get pix tomorrow. They don't look like the pix I've seen here. They are black, no fabric, very industrial-looking; metal corners all around. Heavy duty, road-worthy stuff.

In that case they may be pro-sound variants, which Klipsch dallied in for a time. They also may be theatrical models.

[lbwdog]

Originally Posted by billfitzmaurice

The K33 dates back to the original Klipschorn, 60 years ago, and was originally produced by EV, as were the mid and HF drivers. All of the KHorn hi-fi variants were designed when 20 watt amplifiers were the norm.
In that case they may be pro-sound variants, which Klipsch dallied in for a time. They also may be theatrical models.

Sounds like they are from the industrial line that Klipsch had in the 70's.

The actual LaScala was a single cab with horn loaded 15" woofer, a mid compression driver with horn, and a HF tweeter horn. A band I knew in 1970 used four for their PA and sounded great, but today's components are much more sturdy.

I love old Klipsch speakers for hi-fi, and have a pair of '73 Heresys myself. Klipsch has a great online forum and museum pages, so you'll probably find out anything you want there.

[BillyB_from_LZ]

I think you're missing parts of the URLs!