ALTEC 1215A CABS

[thevott]

Altec's are high efficiency loudspeakers. They are designed to produce clean sound at high output but with a reasonable amount of power. The 421 is probably more durable than many other Altec drivers but will most likely be destroyed by a 2,000 watt amplifier. Because you are using a monster amplifier and are after train derailing output rather than sound quality you should probably consider a more indestructible high power handling driver, perhaps a JBL 2226 (1200 watts) or whatever. It is alway sad to see a premium woofer toasted by a giant amp.
Because you are new to the PA world you are definitely on a good forum though as Altec Lansing paved the road for the modern public address---If you have a chance to listen to a good Altec system you will understand why. Even my "little" 65 watt Model Nineteens will rattle the wine glasses out of the cupboard it you leave the door open, and do it with reference quality sound.

Have fun with your project!

thevott

PS: 421 are often available on Ebay.

[thevott]

Hey, I was just citing an indestructible woofer as an alternative to the 150 watt Altec. Remember, he doesn't care about sound quality as much as output. Personally, I would load it with the 421s (like Altec did) and run the system with a reasonably sized professional amplifier (like Altec intended).


thevott

[scott fitlin]

I hear you, but the celestion is a suitable woofer for that horn, has extreme power handling capability, and will play VERY loud, and will sound good with the type of program marco plays! Also a fairly indestructible driver!

As for the 421 drivers, your correct! They sound great, the beauty of them was you didnt need much power to get them to go! Remember that back in the mid 70,s the Crown DC-300 was the pro amp of the day! The 421,s were designed to give maximum output with the amps of that era! Conversely, even on a DC-300A, with much of todays recordings, especially Hip Hop, and Techno, and the amount of very low frequency energy present in these recordings, the 421,s will not hold up to the sustained high levels Marco wishes to play at! I do feel that sonically the 421 would be the BEST sounding, but it will not withstand the abuse of extreme high level low frequency output! Even on a DC-300 they will be at their limit and beyond with todays Hip Hop and reggae, and techno recordings!

However, the Celestion 15 WILL take the rigors of todays recordings, withstand HIGH levels of input, and sound good!

[thevott]

I read an article a few months ago regarding failure of JBL/Urie monitors in recording studios. Evidently they have been getting toasted lately from too much low frequency! The article outlined the addition of subwoofers to these systems to save money on frequent reconing costs. Its just not like it used to be is it?

thevott

[scott fitlin]

The music is different today! And amplifiers and playback levels are very different today! years ago the music did not have as much low frequency as today! Todays digital recordings have very low frequency in them, and many of the older high compliance suspension woofers dont have enough excursion to handle the large low frequency signals! Years ago we didnt listen to music as loud as we do today! For instance, nightclubs today can have levels of 122db all the way to 140db! Years ago levels at a nightclub were on the order of 112 to 115db!

We also didnt have amplifiers like crown macro tech 5000 VZ,s with output ratings of 2000wpc @ 4 ohms!

Now, this doesnt mean that vintage speakers dont sound good anymore, quite the opposite! In many cases they sound far superior to todays products, but as you see, guys want to use amps with extremely high power and play at extremely high levels! Unfortunately, many of the fantastic sounding vintage woofers just will not hold up under this use!

Since this is what Marco has asked, I gave him what I feel is the best offering considering the enclosures hes got, and the music and power he wants to use!

For the record, I am a 421-8LF freak! I grew up on these! I loved the way they sounded. So efficient, and they had a very fast snap to them! Very clear, you heard every note, and didnt need mega watts to achieve serious output! But, I make my recommendations according to what the end user plans to do! And I feel the Celestion is the way for marco to go!

[scott fitlin]

NO WAY! The JBL 2226 is NOT the right woofer for an Altec 1215 cabinet! Deep angle, straight side cones work much better than the pancake shape JBL 2226! Now, as for power handling and sound quality in a folded horn, the Celestion Frontline 15 is superior to the JBL 2226! On top of that, the 2226 is overpriced!

The 2226 is a decent sounding woofer in a ported enclosure crossed over at 400hz or lower! But the Celestion is far more suited to the Altec 1215 cabinet!

[Marco33980]

Well...I'm gonna give the Celestion Frontlines a try.

A couple of questions....is it true when u put the boxes side by side your making the mouth bigger so inturn you will get a lower frequency response??

And when I put these Celestions in, if I'm not happy with the low end, can I put polyfill or firberglass in the sealed enlosure to make the cab get a little lower?? Or does it not work that way with horns??

[scott fitlin]

Yes, you can increase the flare rate of the horn by putting two together, and this will get you down a little lower in frequency, and offer mutual coupling which yields an increase in efficiency! Putting the two cabinets together is a good idea!

You can play around with the insulation inside the chamber. The more you use the less upper bass response you will hear! Too little or too much is not good! Its a balancing act for sure, but you will find the amount that makes the box/driver combo sound the way you want!

Even though the Fs of the Celestion is 38hz it will actually go a bit lower! It wont get you down into the 20hz region, but for the music you will be playing you dont need response that low! Your looking for the KICK, PUNCH, and GROWL! Believe it or not, alot of bass we hear that we THINK is DEEP bass is actually higher in frequency than we think it is! Much of the DEEP bass energy we hear with Hip Hop, and techno music actually is in the 40hz to 80hz range! This range is perfectly suited for the celestion 15 and the Altec folded horn!

I will make another recommendation as well! What type of bass sound best describes what you wish to achieve? Do you want the " Car Bass " sound? Or a " Dance Club " bass sound?

If you desire a sound like the groaning car bass heard everywhere, on streets today cross your subs over at 80hz! If you want your bass to be punchy, and kick like a nightclub, cross your cabinets over at 100hz! Play with this and see what sounds best to you! personally, I like 100hz with 18db butterworth filters!

[scott fitlin]

BTW, I would stack the two 1215,s instead of putting them side by side!