My new speakers

[dstamand]

Hi.

This is my first posting on this board. I have been browsing it for the last week or so, very informative, thank you. Last night I was given the speakers shown in the pic below. I am all excited! The place from where I got them has had them since the 1960's. I intend to make them my main stereo speakers.



If the pic I tried to post above does not work, you can go to the following website to see all 8 pictures:

http://members.shaw.ca/dwightandpatti

Both horns and all four speakers work and sound great to me. The HF horn is a 511b/808-8A. Below is a 15" and then another 15". The bottom two are not crossed, they just get paralleled. All four 15" speakers are unblemished. To me they appear to be some relatively recent non-altec replacement - I could not find any brand on them, only a number. Tonight I have been draqging out select choices of my vinyl, what a gas(LAPO Mahler 3rd, Milstein Bach Partita No.2). I only have speaker cable hookups for one speaker - will get to RS tomorrow and get both of them going.

The top box with the horn is 3/4" 6 ply plywood, old, painted black, solid. The bottom box with the BR hole is the same. The middle is different - it has metal corners and a black vinyl covering. It appears to be not as old and it was inserted between the other two.

My questions for anybody would be:

1) Have you ever seen this type of configuration before? Probably a band or sound rental place just wanted the 2nd 15" for extra volume eh?

2) Do you recognize the bottom box design with the little port on the bottom? Is it a legit Altec type or just a box?

3) Does anybody recognize the brand of the 15" speaker with the pressed aluminum spider?

4) Does anybody know what Voltage and Capacitance rating I ought to upgrade to in the RC filter? That one is looking pretty old and tired...

These speakers sound so good to me now it will be some time before I grow critical, if ever. Nevertheless I would welcome hearing what any of the knowledgeable forum members would suggest regarding tweaks, upgrades etc. Right now, though, I am in the first flush of just sitting in front of them in my garage and listening to them.

Just had to share it with somebody!

sincerely,

Dwight

[Roland N R]

I am jealous, lucky you!! Bottom cab looks like an 816...a chopped version of the 825-828. Top is a take off on the same. Due to the horns greater output good idea to have two or more drivers per horn to match their output since HF padding down reduces the quality of the sound some what. Combining the two horn cabs also gives horn loaded output to probably below 100 Hzs....all good. The LF 15" drivers may still be altecs unable to r/o from the picture. Need more details regarding specific drivers and crossovers. Likely has a 500 cycle 2nd order typical of Altec installations. Again congrats you have a really fine high efficiency system which would cost thousands to equal.

[selmerdave]

Let me get this right, someone GAVE you those? Wow. What are you using to drive those, it wouldn't take much. If I were you I'd redo the crossover so that HF attenuation is removed, although maybe that's already been done I don't know if that was the full crossover in the picture. Not sure what that capacitor is but there is a likelihood that it could be replaced with something better.

I doubt the 15's are Altec, although I wouldn't necessarily know, I just haven't seen an Altec with a square magnet before. Enjoy!

Dave

[Charles Chance]

They also look well protected against flying beer bottles.

[dstamand]

djk on AA says the 15" are 719 Carbonneau OEM, made in 1970 or 1980. Carbonneau was made by Rockford Audio Division aka RAD.

[dstamand]

I just had to come back on and rave a bit - got both speakers going after some soldering of loose connections and sweeping out mouse droppings - I am listening to Bernstein LSO Mahler 2nd Symphony, one of my reference recordings I use to audition speakers. I have it on both CD and vinyl. The opening of this symphony is good for assessing the low definition - I liked how you can hear the tune being played by the cellos and doubled an octave down by the double bass section - you can hear both sections - its not all just a blob of bass notes. Then the last movement separates the men from the boys in terms of stereo system/speaker - very demanding on a sound system. It has very quiet choral passages, solos lines in voices and various instruments, and then ends in a crashing bombastic climax with organ, choir, percussion and orchestra that should push you back into your chair and make your hair stand on end. These big old dance hall speakers carried me away the way I wanted, using my $35 garage sale Sanyo SS integrated amp. I knew what I was searching for: something that would handle the subtle soft parts, then keep the detail in the complex orchestral passages with big sudden dynamic contrasts. On this system in my garage, though, I could let it be loud, it was glorious, not painful. Like the CV motto. Whew, OK, now I am going to have some fun - wake the neighbours by cranking up some E. Power Biggs.

L8r

Dwight

<font color="#FFFFFF" size="1">[ November 10, 2003 12:06 PM: Message edited by: Todd W. White ]</font>

[Roland N R]

Dwight:

For the first time looked at the 8 pictures. 15" drivers with square magnet don't look like Altecs perhaps they are CTS but "Carbonneaus" sounds classier. Again don't underestimate this design just because they are "old dance hall speakers" Horn loaded bass to below 100Hz is uncommon sound great as you are noting in the midbass ie: Cellos and stand up bass. Suspect deep bass below 60Hz will be slightly deficient since 816 cabs vented output is limited to that. But really little info there in most LPs anyway. Subs matching the quality and SPL of the horns output are indeed rare. Horn subs and infinite baffle subs are best followed by large vented boxes with multiple drivers. I would stick with corner placement and/or wings if you really wanted more bass. By the way check out the vintage Altec 820 system in the archives. This was a corner design with double 15" and 808 multicell 800 cycle horn = kicking butt in the 50s and still now.

That crossover needs to go!!! Measure the specific impedance of your drivers and just make a second order XO set at 675Hz or thereabouts. Use air core inductors and polyprop caps. The higher XO point works better with this horn and driver.

Best

Roland

[scott fitlin]

welcome to reality. Horn loaded rules!

[dstamand]

Thanks everybody for the info and responses.

Yes, considering that there are four 15" drivers, you would think the bass would be bigger and deeper.

Roland, what does "CTS" stand for?

Are you saying the cap has to go because it is blunting the HF? I thought it was needed to protect the 808-8A from the amplitude of the LF, is that correct?

The 15" speakers measure 7.4 ohms DC resistance. I learned about high and low pass filters, amplifiers, log dB scale etc. when I took my tech diploma 10 years ago, but have forgotton some of it, and have never made crossovers before. I did a google search and am using this webpage:

http://www.colomar.com/Shavano/crossover12db.html

Is the following correct then?

1) remove the resistor and cap from the 511b/808-8A. (BTW, I measured the offending cap to be 4.3 uF and the R is 1.2 ohm.) Wire in a high pass filter as per Shavano site for the HF horn.

2) Wire in a low pass filter for the two 15" speakers.

Cap would be 50 V RMS min rating. Inductor would be min. 20 AWG and ~ 1 ohm DCR. I would make two external boxes, one for each side. How does this plan look? Or did you mean the 808-8A should get nothing, just a low pass on the two 15"?

[dstamand]

My 15" drivers (one of them anyways)are stamped with the number: 2115 719004. I was looking up speaker source codes on the following site:

http://www1.korksoft.com/~schem/mods/datecodes.htm

According to this site my speakers are not CTS (which I realize now is a brand), but Carbonneau -the first three digits, 719 is the Carbonneau manufacturer code. The next digit is the year, 0, which would be either 1970 or 1980. The last two digits are the week, so the spaekers were made in the 4th week of 1970. I don't know what the 2115 is about, maybe the 2115th unit made.

I would appreciate if anybody can confirm if I am right or not on this.

Thank you,

Dwight