Altec Novice

[speakerdave]

Just wondering--Why would someone in the home of classic Tannoy duplexes be looking elsewhere for speakers suitable to use with 300B amps?

David

[zelgall]

Most Tannoy's aren't nearly as effcient as the average Altec. They tend to be around 94Db or so.

[Eric23]

Good question. To be honest, I haven't really heard many old tannoys. The 'general' rule with Tannoys, as I understand it, is the older and bigger, the BETTER. I've heard very old and big tannoys and found that, while excellent and immediate, you can hear too much of the cabinet in the sound, especially when they are in smaller spaces.

I haven't got a problem with being 94db. Ok, 97 would be better but 94 should be fine with the amps I have in mind.

Altec models with true compression driver horns with big bass drivers, This is an attractive feature.

Do you have any recommendations on what Altec/s to look out for?

[Mike Gibson]

Eric, I sent you a PM on the Valencia's.

[homme_de_terre]

Hi Eric,

I agree with what Bob said, regarding the 604's frequency response, yet I'm sure that it only holds true for the pre-Mantaray types of the 604. The later models 604-8H and 604-8K sported a constant directivity horn, named "Mantaray" by the Altec marketing folks. The stock crossover is equipped with an MF eq circuitry which seems to be mandatory for CD horns. I still believe the 604 is better suitable for home application due to its point-source character. I haven't heard M19s in my home environment but a friend has A7s in room that is as big as mine. I think it's overkill and the MF/HF sources just don't blend over that short distance.
By the way, I also followed Bob's advice, ditched my idea of building a passive time aligned x-over for my 604s and went active.
A Rane AC22 x-over, a cheapy Behringer parametric eq, solid state for the bass, tubes for the HF.
Took me a while to get the frequency response right but it sure was worth the effort.So...thanks Bob :-)
Don Patten once said "Time alignment is like freeing the music from the mud."
He's right and I think the active setup makes for some addidional "demudding".
The next thing I might try is the design of an FIR x-over based on an Analog Devices Sharc evaluation board. Any of you guys ever tried that?

Manfred

[joyspring]

Hi Eric:

JBL's history is interesting but if you dig a bit deeper on Don McR's site, Altec's post-1960s history is terribly disheartening.

The combination of LTV's straddling Altec with staggering debt and - according to a few who worked at 1515 Manchester - managerial arrogance ("We're the best; we don't have to improve") that severely limited research and development, it's absolutely no surprise that JBL very quickly assumed the leadership position in professional audio.

Many of the talented ex-Anaheim Altec folk eventually moved on to either working or consulting for JBL, Cetec-Gauss, Electro-Voice so in a sense, the spirit of Altec lives on. The names Henricksen, Ureda, the Davis' immediately come to mind.

"Having said that, if I HAD tried the 4312's with a 300B amp..."

So far as using your 4312s (or any other loudspeaker) with different amplifiers, provided you're running within the amplifiers' linear range and that the amps can handle the load reactances presented, you will _not_ hear any difference between amplifiers. If you do, then there is a problem with one of the amplifiers.

"Also, have heard that changing the stuffing material behind the mid driver might have changed the sound a bit, too."

The JBL 4312s are quite nice as is -- I'd leave them alone.

"Incidentally, on the JBL (Harman) Japan website you can see bang up to date versions of the 4312 with revised drivers, sometimes horn-loaded like the K2?s."

I truly believe that's to pander to the Asian market which has really subscribed to the `vintage is better' rubbish. IMHO, I believe that Harman Japan simply cobbles together systems incorporating some sort of horn/compression driver HF section or even just a `vintage' model number as bait, and the Asian consumers bite.

I doubt these systems have the same developmental budget/schedule as the normal JBL systems.

"Bob and Altec fan, the model 19 might be better for me, then? Do you have any more info on it?"

Altec Model 19 brochure

Altec home 1978 catalogue

"Regarding power requirements. Have been advised to go for something like a parallel s/ended amp in the 18 watts region. I'm not looking to play loud. In fact, clarity and dynamic range at low to medium volume levels would be of more benefit, as would the ?immediacy? one associates with efficient speakers."

The attribute of `immediacy' is simply having enough dynamic headroom to track the dynamics of the source material.

Perhaps twenty years ago, high-efficiency loudspeakers had the monopoly on this attribute; however, many low- to mid-efficiency loudspeakers now possess `immediacy'. All you need is enough electrical power and loudspeakers that have low power compression (loss of SPL from increasing voice coil resistance, due to heat).

Now amplifier power is relatively inexpensive and modern drivers have much better thermal management.

This is why - knowing the logarithmic relationship of electrical input power to acoustic sound pressure level and the fact that 24-bit digital audio will soon be commonplace - the logic of small SET amplifiers utterly escapes me :-/

My personal recommendation: a large, convection-cooled amplifier. A second-hand Crown (Amcron) DC-300 at 155 watts/ch. would be an excellent choice for a pair of Model 19s. Or a large Bryston, Krell or Hafler if you desire more exotic kit.

BobR

[RonSSS]

BobR,

I don't understand why you have to try and convince Eric that his 300B SE amps are no good. What's the point?
He likes them, isn't that good enough?

Ron

[joyspring]

Hi Manfred,

The later 604s did incorporate heavy HF equalisation in the crossover network to flatten the axial response of the even-power-response Mantaray horns. The additional HF energy output of the Tangerine phasing plug cannot be overlooked as well.

Suppose then, the Model 18 (604-8H / 604-8K based) would also be a contender for Eric as well

Altec Model 18 brochure

In any event, the latest Altecs (Models 18 / 19) did incorporate much improved crossover networks than the earlier systems.

"The next thing I might try is the design of an FIR x-over based on an Analog Devices Sharc evaluation board. Any of you guys ever tried that?"

Nope, haven't tried it though may investigate doing so when time permits.

I'd previously been toying with BruteFIR (previously nwiir) under Linux (using a 24/192kHz RME HDSP9632 as I/O) but ran out of CPU in realtime very quickly...

Embedded is definitely the way to go.

BobR

[Eric23]

Bob, Ron and Manfred

Apologies. I wasn't very clear in my first post. I do not actually OWN a 300B amp yet. Rather, I am about (over the next few weeks) to audition a few, through shop and home demo, and will then decide to buy or not. There are other valve (tube!) possibilities, of course, such as KT88 and EL84.

I currently own a Bryston 4BSST 300-watt amp. The first step, though, is to upgrade my speakers and, luckily, there are a few dealers who stock vintage Altec here in England. Once done, I will then be able to directly compare tube amps to my Bryston in relation to the speakers chosen. I'll let my ears do the deciding on that one and will be happy to post the results. It's going to be an interesting summer!!

Bob, regarding experimenting with the stuffing behind the mid-driver: A JBL engineer, who claimed he was involved in the original design of the 4310/11/12, told me about the stuffing via email. It was his idea and one that I never tried before selling those 4312?s. This engineer also suggested using those speakers with tubes instead of solid state, which I also did not do. I suppose you could say I didn?t really listen to him!

Thanks for all the info. Will need to read over it for a couple of days. There?s a lot to take in and digest: - 604-8H / 604-8K drivers, latter day crossovers etc, etc. And must actually go and LISTEN to some Altecs ASAP.

[MikeInNH]

I'm sorry I have to disagree with Rob on the 300b amp. Something has to be said for a SET type amp that. I'm NOT an electrical engineer, so I can't tell you what is going on here.

There is somehing that is more musical, more mellow...I don't know....Maybe it's the type of music I play....I don't know...but there is SOMETHING there.

I was convinced that the High-end Mac Integrated Amp (MA6100) that I owned was better then any 20+ year old amp by Marantz. I was blown away at the sound difference between the two amps. We then brought in another amp (Crown DC 300A) and the 20+ yo Marantz still was easily the winner. However hooking up the Marantz to a nice pair of Boston Acoustics did not offer the same results. The Mac ma6100 seemed to work the best with the Boston Accoustics (although the Crown was pretty close).

I was really blown away with the Marantz amps, but at the time I couldn't afford a refurbished pair of 300b's or any of the New Set amps out there by companies like Carey.