Altec 604E’s - A soon to be proud duplex owner.

Audionut

Next Round Is On Me
Getting these gems brought back to life by Bill at GPA can be a trying experience, but he is THE man to put the magic back into them.

Hang in there, I think you will find these become the heart of an amazing system and a little grief on the front end will fade from memory fast.

And congratulations!
Thanks Billfort, I agree in them going to the best place possible and looking forward to getting them back. I’ve been perusing the web and stumbled on the utopia enclosure, along with winding side vent cabs.... decisions, decisions! I want to maximize LF output without jeopardizing MF.
 

dowto1000

Junior Member
I think that you want to do at least about 9.5 cubic feet, and MLTL enclosures. Greg Monfort , ( GM on the Altec User's Asylum ) is the guy who has written this up, done the math. Also, private parties Jay Fisher in Santa Monica , CA , Stephaen Harrell of 6 Moons has 604 MLTLs, as also Dennis Fraker at Serious Stereo run MLTLS. This should point you in the right direction !!

Be sure to make them out of ONE INCH MINIMUM Baltic Birch, or Europly, and see if you can get 1 1/8th or 1 1/4, with no internal bracing..

I spent the first weekend this October, in a Denver hotel room with GPA 604s, and the Serious Stereo MLTLs, and I can tell you, BASS with his 2A3 amps and system wiring was fabulously good, great freedom, tuneful and VERY deep !!!

http://www.seriousstereo.com/serious_stereo_transmission_line_speaker.html

Listen to the drivers casually with NO enclosures to start, and do your homework, so as to pick the best enclosure. I am pretty sure, it is what I'm discussing in this post.

Contact me, and I'll help you with a proper DC two stage amp you can build for them.

Have FUN !!!!!


Dowto1000
 
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TubeHiFiNut

Administrator
Thanks Billfort, I agree in them going to the best place possible and looking forward to getting them back. I’ve been perusing the web and stumbled on the utopia enclosure, along with winding side vent cabs.... decisions, decisions! I want to maximize LF output without jeopardizing MF.

The best advice I can give you is to take your time and do the research.

Listen to Anthony's enclosures at length.
 

Audionut

Next Round Is On Me
Thank you dowto1000 for the link, Baltic birch would be ideal if I’m going clear but not too sure how well they’d look with stain. 1” eurobirch is a little on the rare side too. I’m thinking MDF or HDF will do nicely with veneer of choice on top or factory walnut with a mdf core.
I would like to build a nice tannoy style furniture piece enclosure but think I may be over complicating it.

Thank you also Tubehifinut, I may be visiting Anthony a little more than usual if he will have me.

Also I got a hold of Bill this morning and was given a bit of bad news about a bad diaphragm (insert old style cash register ringing up sound), told him to replace the other one while he was in there so we are starting on a level audio playing field. He noted they will be better than new! So my babies will ship today and I should be receiving them Monday at the earliest. Woohoo!
 
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opa1

Moderator
Staff member
Good decision on the diaphragms. Your going to love these drivers! It's worth it. :)
 

billfort

Administrator
Staff member
A couple small points about the 604E that you have, based on personal experience (I've spent a lot of time listening to Es).

Don't expect really deep bass; what is there is fantastic - fast, big tone, snap and bite - sounds SO much like the real thing - but putting an E in a huge cabinet isn't going to get you real deep. Mr. Hardy might certainly have a more pertinent opinion (being an E owner) but I'm thinking don't bother shooting for larger than 9cuft - they just aren't deep bass monsters.

One of my favorite cabinet designs for these is the 620a - about 9cuft with a big wide baffle - I feel these make for the nicest blending of upper-bass to lower mids that narrower cabinets just don't seem to pull off as well. Also, I heard the exact same 604Es with Mastering Labs crossovers in the same system, in 620a cabinets built in 2 different ways; once in well braced 3/4" Baltic birch and once in massive monsters made from 1-1/2" walled HDF. IMO, the bb cabinet won - stood out in speed and presence, really seemed lighter on it's feet and let the 604s soar, where the heavy guys maybe had a little more deep bass but also seemed kind of bloated and a little deader - lost some of that 604 presence and sense of ease. The beautifully veneered HDF cabinets didn't last long in that system.
 
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Kyle

Junior Member
A couple small points about the 604E that you have, based on personal experience (I've spent a lot of time listening to Es).

Don't expect really deep bass; what is there is fantastic - fast, big tone, snap and bite - sounds SO much like the real thing - but putting an E in a huge cabinet isn't going to get you real deep. Mr. Hardy might certainly have a more pertinent opinion (being an E owner) but I'm thinking don't bother shooting for larger than 9cuft - they just aren't deep bass monsters.

One of my favorite cabinet designs for these is the 620a - about 9cuft with a big wide baffle - I feel these make for the nicest blending of upper-bass to lower mids that narrower cabinets just don't seem to pull off as well. Also, I heard the exact same 604Es with Mastering Labs crossovers in the same system, in 620a cabinets built in 2 different ways; once in well braced 3/4" Baltic birch and once in massive monsters made from 1-1/2" walled HDF. IMO, the bb cabinet won - stood out in speed and presence, really seemed lighter on it's feet and let the 604s soar, where the heavy guys maybe had a little more deep bass but also seemed kind of bloated and a little deader - lost some of that 604 presence and sense of ease. The beautifully veneered HDF cabinets didn't last long in that system.

Absolute ditto on this post! My experience with my E's mirrors Bill's thoughts - 620A size and shape built of BB and good but not excessive bracing. I used a couple of different boxes for these drivers with less good results. The crossover will be a major factor in the sound you end up with. You need to choose a flavour you enjoy because they're all different and all sound "the best" to someone. I like the Jeff Markwart version with a few mods. I bought his 604's that he used for his initial design and copied his design for the xovers for those as well.
I also built an MLTL ala Greg Montieth (sp?) that worked very well with 604-8-G's and also used a factory 620A box with good results.
 

Audionut

Next Round Is On Me
A couple small points about the 604E that you have, based on personal experience (I've spent a lot of time listening to Es).

Don't expect really deep bass; what is there is fantastic - fast, big tone, snap and bite - sounds SO much like the real thing - but putting an E in a huge cabinet isn't going to get you real deep. Mr. Hardy might certainly have a more pertinent opinion (being an E owner) but I'm thinking don't bother shooting for larger than 9cuft - they just aren't deep bass monsters.

One of my favorite cabinet designs for these is the 620a - about 9cuft with a big wide baffle - I feel these make for the nicest blending of upper-bass to lower mids that narrower cabinets just don't seem to pull off as well. Also, I heard the exact same 604Es with Mastering Labs crossovers in the same system, in 620a cabinets built in 2 different ways; once in well braced 3/4" Baltic birch and once in massive monsters made from 1-1/2" walled HDF. IMO, the bb cabinet won - stood out in speed and presence, really seemed lighter on it's feet and let the 604s soar, where the heavy guys maybe had a little more deep bass but also seemed kind of bloated and a little deader - lost some of that 604 presence and sense of ease. The beautifully veneered HDF cabinets didn't last long in that system.

Thanks Billfort, I really appreciate the detailed feedback. I’m not a bass head (anymore) but looking for the low frequencies when called for. I can always add a woofer or two (will call on Anthony for this). Baltic birch is looking much more appealing every second. I suppose I can always veneer them if they don’t take stain properly. On a bit of an American walnut kick right now.
 

Audionut

Next Round Is On Me
Absolute ditto on this post! My experience with my E's mirrors Bill's thoughts - 620A size and shape built of BB and good but not excessive bracing. I used a couple of different boxes for these drivers with less good results. The crossover will be a major factor in the sound you end up with. You need to choose a flavour you enjoy because they're all different and all sound "the best" to someone. I like the Jeff Markwart version with a few mods. I bought his 604's that he used for his initial design and copied his design for the xovers for those as well.
I also built an MLTL ala Greg Montieth (sp?) that worked very well with 604-8-G's and also used a factory 620A box with good results.
Can you give more detail on what each crossover has to offer in terms of “flavor”? I’d love to have some mastering labs ones but they are hard to come by. Will likely be building them from scratch.
 

dowto1000

Junior Member
Audionut:

You need to do a MUCH better basic SET amp circuit than what you are thinking of doing, if you want the best possible 604 results.

Sub woofers are not ever needed, in my experience, with 604s.

People add sub woofers because of two primary factors, (1) their entire systems' wiring and its resultant transfer-efficiency-of-energy, is simply not good enough. (2) They use conventionally executed SET amps, with all their WOES, as I have described the last month.

AMP WOES, of SETs used on ALTEC 604s :

ie : The AMPS use chokes over 20 Ohms in DCR, too much capacitance in the filter to the Finals ( robs dynamics as explained by EE, Hasquin ) , use more than two tube stages, and generally, SET amps typically suffer with a VERY poor internal transfer efficiency of energy, ( unconsciously ) through the use of ineffective internal wiring and lay-out.

ALL the above factors, when mis applied to amps, and to ALTEC crossovers, ruins their potential performance, in my opinion and experience.

Some "add tweeters" because they do not know how to multiple bypass the cap positions in their SET amp and speaker crossover, while their SET AMP plays like 99 % of the SETs, narrow band, non-dynamic, and primarily in the midrange.

The best ALTEC system "top ends" I have ever experienced, come from SETs ( and speaker crossovers dudes !!! ) that are multiple bypassed, in every cap position, EZily !!

Mind you, boys and girls, this is all "IN MY OPINION", and...... it is also in my experience !!

I started listening to an original ALTEC 604 in December of 1944, after my Mom brought me home from the hospital.

I hope this Forum is broad enough, for me to express my honest opinions. My intent is to inform, not to offend others. If you follow up on my suggestions, you will discover I am not too far off base at all !!! Have FUN, I DO !!


Dowto1000
 
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Audionut

Next Round Is On Me
Audionut:

You need to do a MUCH better basic SET amp circuit than what you are thinking of doing, if you want the best possible 604 results.

Sub woofers are not ever needed, in my experience, with 604s.


Mind you, boys and girls, this is all "IN MY OPINION", and...... it is also in my experience !!

I hope this Forum is broad enough, for me to express my honest opinions. My intent is to inform, not to offend others. If you follow up on my suggestions, you will discover I am not too far off base at all !!! Have FUN, I DO !!

Dowto1000

Thanks for your informative and passionate response Jeff. I truly enjoyed the part about not needing subs (time will tell of course). I was looking at some Serious Stereo amps (eBay) but I’d have to sell off all my other gear to get them (not ready to do that just yet). Crossovers will be my first order of business and cabinets next. Amps will be the last item as they will likely be thee most costly part of the arrangement. Note I have a variety of tube/solid state amps that will get their turn at courting and eventually marrying my babies!
I am more than ready to sample your amps too by the way so dont be shy, I’m sure a few others here would not mind either. Building my own will likely be part of my end all system plan (eventually). For now i’ll enjoy my journey there.
 

MikeT.

Senior Member
Congrats on the 604’s @Audionut ! Love to see the pics of the rebuilt drivers. Hope you didn’t post them already. I’ve been diving in and out of this thread. The idea of these large concentric drivers (Altec, Tannoy) is very intriguing and tempting.

Don’t have the room for them right now but maybe someday.

Congrats again!
 

dowto1000

Junior Member
Thanks for your informative and passionate response Jeff. I truly enjoyed the part about not needing subs (time will tell of course). I was looking at some Serious Stereo amps (eBay) but I’d have to sell off all my other gear to get them (not ready to do that just yet). Crossovers will be my first order of business and cabinets next. Amps will be the last item as they will likely be thee most costly part of the arrangement. Note I have a variety of tube/solid state amps that will get their turn at courting and eventually marrying my babies!
I am more than ready to sample your amps too by the way so dont be shy, I’m sure a few others here would not mind either. Building my own will likely be part of my end all system plan (eventually). For now i’ll enjoy my journey there.


You have a GREAT open attitude. I will be glad to help you, with a DC amp build you can DIY yourself, spoon feed you, and it WILL work and be AOK, at a very very high performance level. Better than most of what people use. Amps ARE the weakest part of the whole audio chain, and so, I DIY them, and try to help others with a similar interest, as people did for me, decades ago, before they died !!

Dowto1000
 

dowto1000

Junior Member
You talking about Greg Monfort? I think he did the alignment on this set. http://6moons.com/audioreviews/altec/dream_3.html


Yes, that is GM . I would use 1 inch Baltic Birch or Europly, and as MINIMAL internal bracing as possible.

Notice, how NONE of the film caps are multiple bypassed. TSK, TSK, TSK.

HERE IS MY a7 CROSSOVER'S TWEETER'S CAP , ABOUT 7 FILM CAPS in one bundle, CHOSEN BY EAR. The "least"P1010015.JPG one could do is bypass ala Marzio and Jelasi ( main cap, 0.22, and 0.022 uF ) as a starter, hear that !! DC LINK main cap and FKP1, all WIMAs. :
 

dowto1000

Junior Member
Congrats on the 604’s @Audionut ! Love to see the pics of the rebuilt drivers. Hope you didn’t post them already. I’ve been diving in and out of this thread. The idea of these large concentric drivers (Altec, Tannoy) is very intriguing and tempting.

Don’t have the room for them right now but maybe someday.

Congrats again!


I had a Tannoy Monitor Gold 15 inch Duplex, my FIRST speaker purchase outta college.

I my OPINION, I would pass on Tannoy, go ALTEC, it is HARD to beat that compression driver's powerful magnet structure and design, just feed it well !!

Dowto1000
 

dowto1000

Junior Member
Thanks for your informative and passionate response Jeff. I truly enjoyed the part about not needing subs (time will tell of course). I was looking at some Serious Stereo amps (eBay) but I’d have to sell off all my other gear to get them (not ready to do that just yet). Crossovers will be my first order of business and cabinets next. Amps will be the last item as they will likely be thee most costly part of the arrangement. Note I have a variety of tube/solid state amps that will get their turn at courting and eventually marrying my babies!
I am more than ready to sample your amps too by the way so dont be shy, I’m sure a few others here would not mind either. Building my own will likely be part of my end all system plan (eventually). For now i’ll enjoy my journey there.

I spoke to my expert friend, and he says, my suggestion of 9.5 cubic feet was wrong. If its a 604E, an MLTL he says, off the top of his head, would be 7.7 to 8.7 feet. ALL you need to know about MLTLs is on line he says. He suggests trading in the newly rebuilt 604Es on the GPA 604s, which he characterizes as being vastly superior, and that there is NO reason to own any other 604. That GPA driver uses a 10.63 to 10.73 cubic foot MLTL enclosure, 10.7 on average and YOU determine the port size, with an adjustable port, by your ear.

Hope this information helps you some. Have FUN.

Dowto1000.
 
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