Hello all,
*Note: I also started a thread at the Altec Board and this is a copy of it. http://www.hostboard.com/forums/f700/280751-best-choice-cab-gpa-604-8h-iii.html
I'm starting this thread for an acquaintance who I sold my tube amp to. And this is specifically for the GPA 604 III driver: http://www.greatplainsaudio.com/downloads/604_8H_III.pdf
And the GPA crossover: http://www.greatplainsaudio.com/downloads/N604-8A.pdf
Or perhaps this crossover instead with the level controls: http://www.ebay.com/itm/Altec-Lansi...a77c54e&pid=100011&rk=3&rkt=4&sd=111609536780
He was recommended the Stonehenge V cabinets by Bill at GPA, and I mentioned that there are some different designs that would be worth checking out, like an MLTL design. I've read some on GM's before and mentioned it to him and so here I am. I cannot seem to find any plans for them though.
Are there any already completed GPA 604 III MLTL cab plans available?
Here's some particulars:
1- He will be using a low powered valve amp. I sold him mine that is 6watts rms, but I think he has a few others as well that maybe are more powerful.
2- Listening space 22'x30' (and I think 8' ceiling height)
3- Cabs would be used near both corners of the 22' wall facing out into the 30' long room. He can also use them close to the back wall or out into the room a bit, toed in etc
4- He doesn't mind big cabs, no WAF to worry about here.
5- He can't diy, but has a good cabinet builder that will make them for him.
6- I guess the best would be an all rounder cab that's known to work well, with dims and stuffing specified that wouldn't need tweaking, as he isn't the diy type.
7- Music tastes - Jazz, classical, rock, reggae, girl and guitar, pop etc.
Any help would be appreciated as to what might be a better design for him than the Stonehenge V.
A big cab is okay and SQ is everything.
Note* My thoughts were that sealed would work well letting them roll off naturally, and use subs under them etc. Like Lynn Olson with his 416 design etc. But then I figured a one cab solution to be a better fit which could squeeze out all that the 604 has to offer, and it would also be easier for him to set up etc. He lives far away from me so I can't help tweak them, like add and reduce stuffing amounts etc.
I didn't want to steer him wrong, and thought to come here and ask for your opinions for what would be considered as a good all rounder cab for the GPA 604III specifically.
Thanks for any help,
Dave.
*Note: I also started a thread at the Altec Board and this is a copy of it. http://www.hostboard.com/forums/f700/280751-best-choice-cab-gpa-604-8h-iii.html
I'm starting this thread for an acquaintance who I sold my tube amp to. And this is specifically for the GPA 604 III driver: http://www.greatplainsaudio.com/downloads/604_8H_III.pdf
And the GPA crossover: http://www.greatplainsaudio.com/downloads/N604-8A.pdf
Or perhaps this crossover instead with the level controls: http://www.ebay.com/itm/Altec-Lansi...a77c54e&pid=100011&rk=3&rkt=4&sd=111609536780
He was recommended the Stonehenge V cabinets by Bill at GPA, and I mentioned that there are some different designs that would be worth checking out, like an MLTL design. I've read some on GM's before and mentioned it to him and so here I am. I cannot seem to find any plans for them though.
Are there any already completed GPA 604 III MLTL cab plans available?
Here's some particulars:
1- He will be using a low powered valve amp. I sold him mine that is 6watts rms, but I think he has a few others as well that maybe are more powerful.
2- Listening space 22'x30' (and I think 8' ceiling height)
3- Cabs would be used near both corners of the 22' wall facing out into the 30' long room. He can also use them close to the back wall or out into the room a bit, toed in etc
4- He doesn't mind big cabs, no WAF to worry about here.
5- He can't diy, but has a good cabinet builder that will make them for him.
6- I guess the best would be an all rounder cab that's known to work well, with dims and stuffing specified that wouldn't need tweaking, as he isn't the diy type.
7- Music tastes - Jazz, classical, rock, reggae, girl and guitar, pop etc.
Any help would be appreciated as to what might be a better design for him than the Stonehenge V.
A big cab is okay and SQ is everything.
Note* My thoughts were that sealed would work well letting them roll off naturally, and use subs under them etc. Like Lynn Olson with his 416 design etc. But then I figured a one cab solution to be a better fit which could squeeze out all that the 604 has to offer, and it would also be easier for him to set up etc. He lives far away from me so I can't help tweak them, like add and reduce stuffing amounts etc.
I didn't want to steer him wrong, and thought to come here and ask for your opinions for what would be considered as a good all rounder cab for the GPA 604III specifically.
Thanks for any help,
Dave.
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That's great news then. I was reading at a forum earlier that mentioned the Bisons and that these were designed for small to medium sized rooms, but I don't suppose it would matter that much. I know that he can go big like 10-12+ cubic feet no problem, and I was also interested in what GM would think re the 604 III
The guy I sold my amp to has your Frugal Horn XL cabs and really enjoys them. He also has your fe206en drivers with your phase plugs. Also he was looking at some of your smaller bookshelf designs you had for sale, to use in his office and linked me some. I said I hadn't heard these newer designs but that you couldn't really go wrong as they should all sound good for their intended purpose.
Anyhow I guess I should try and talk with Scott and see what he thinks of the Bisons in a larger room, or if they could be enlarged some if need be. His room is 22'x30' and I think 8' ceilings. Low power valves will be the amp.
The guy I sold my amp to has your Frugal Horn XL cabs and really enjoys them. He also has your fe206en drivers with your phase plugs. Also he was looking at some of your smaller bookshelf designs you had for sale, to use in his office and linked me some. I said I hadn't heard these newer designs but that you couldn't really go wrong as they should all sound good for their intended purpose.
Anyhow I guess I should try and talk with Scott and see what he thinks of the Bisons in a larger room, or if they could be enlarged some if need be. His room is 22'x30' and I think 8' ceilings. Low power valves will be the amp.
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I found a little bit about the Bison design here in this older thread. *Note nothing is given away as far as dims go, or I wouldn't post it unless it was a known free design.. All that is said is it's 290 liters, so 10.24 cubic feet, Nice!
https://www.audioasylum.com/cgi/vt.mpl?f=hug&m=162175
https://www.audioasylum.com/cgi/vt.mpl?f=hug&m=162175
Does your friend already own the GPA 604-III? It is a great old-school speaker, but there are several better tube friendly new-tech speaker designs.
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Agree on 3-way design: For a 25' x 15' listening room, putting the GPA 604-III in a cleverly constructed 2cuft(0.7) to 3cuft(0.577) sealed cabinet down to ~100Hz for the best possible transient response, and adding crossovers to a real woofer should be studied and discussed with your friend. Low power tube amps can produce strong bass if large woofers are used in large ported cabinets.
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Have you worked with your friend on room modeling to find the best speaker and listener position? Room sim tools will illustrate bass equalization requirements.
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There are a few well developed threads for MLTL designs for the GPA/Altec 604 which are optimized for the dimensions of a sheet of Baltic Birch Plywood... like 55" line height limit.
---
Agree on 3-way design: For a 25' x 15' listening room, putting the GPA 604-III in a cleverly constructed 2cuft(0.7) to 3cuft(0.577) sealed cabinet down to ~100Hz for the best possible transient response, and adding crossovers to a real woofer should be studied and discussed with your friend. Low power tube amps can produce strong bass if large woofers are used in large ported cabinets.
-----
Have you worked with your friend on room modeling to find the best speaker and listener position? Room sim tools will illustrate bass equalization requirements.
==========
There are a few well developed threads for MLTL designs for the GPA/Altec 604 which are optimized for the dimensions of a sheet of Baltic Birch Plywood... like 55" line height limit.
Thanks, I haven't been able to find any MLTL plans specific for the 604h III in my searches, that include all the dims etc.
He likes single driver speakers and has a few and also has some big Maggies. This is his dream speaker though, he really wants the 604 and Bill at GPA mentioned the Stonehenge V to build. I mentioned to him that there are/were some MLTL for the 604's and that this would be the way to go.
Yes sealed and subs etc would be an idea, but he is not a diy guy and simple is better. So a cab for the GPA 604 III that gets the best out of the driver, and that's already worked out that he could just give to his cab maker to build is best.. This is for a KISS principle system etc.
He likes single driver speakers and has a few and also has some big Maggies. This is his dream speaker though, he really wants the 604 and Bill at GPA mentioned the Stonehenge V to build. I mentioned to him that there are/were some MLTL for the 604's and that this would be the way to go.
Yes sealed and subs etc would be an idea, but he is not a diy guy and simple is better. So a cab for the GPA 604 III that gets the best out of the driver, and that's already worked out that he could just give to his cab maker to build is best.. This is for a KISS principle system etc.
The Billfort cabs are interesting as well, although not specifically tuned for the GPA 604 H III drivers. Nice looking and the lower front side ports are an interesting take. Could be a neat style to make into a MLTL, tune lower, and enlarge it a bit.
Billforts Audio Obsession
Billforts Audio Obsession
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Here's a design from across the Pacific for a different 604. Not considering it, but thought some may like to see it if they hadn't before.
https://s-media-cache-ak0.pinimg.com/originals/13/e2/b8/13e2b8de960655b7f7280c022285876f.jpg
https://s-media-cache-ak0.pinimg.com/originals/13/e2/b8/13e2b8de960655b7f7280c022285876f.jpg
Interesting back loaded horn.
I would wager Scott design will be superior to this.
Oh for sure totally, agreed! Just came across it somehow and thought to link it here just out of interest for some Altec fans that maybe hadn't seen it before. I've been searching so much stuff lately and just happened on that one, can't remember how though lol.
Greets!
OK, did I respond? I don't recall.
A quick Google returned these suitable for the 604S3 except possibly vent tuning:
http://www.diyaudio.com/forums/multi-way/259659-gpa-604-8h-iii-build.html
http://www.lansingheritage.org/images/altec/plans/1960's-lf-design/page15.jpg
https://www.audioasylum.com/forums/hug/messages/13/136300.html
Billforts Audio Obsession
There's more with vents near the driver, but don't recommend them unless you want the Altec/JBL 'West Coast Sound', which adds a bump, null in the mid-bass of a high aspect ratio cab.
This, or functional equivalent for mass loading/bracing the driver, general bracing:
http://www.6moons.com/audioreviews/altec/strip_mounted.jpg
http://www.6moons.com/audioreviews/altec/bracing.jpg
My default MLTL alignment for the [Fb] = [Fs] tuning required for high output impedance source is ~58-62" high with the driver offset in the ~0.33-0.42 [inside/i.d.] range depending on desired ear height, 30" wide min. [reduces/negates the need for baffle step compensation/BSC], depth as required [outside/o.d. dims] , ~0.84 offset or use bottom shelf vent or spaced up [adjustable] with bottom floor loading vent. Vent area [Av] = > [Sd]/4. Slot vents < 9:1 aspect ratio. Net [Vb] = [Vas] - [Vas]/1.44. Recommended [Qts'] range ~0.312 - 0.403
[Qts'] = [Qts] + any added series resistance: mh-audio.nl - Home
This cab tuned to [Fs] would be a good one for the minimum net [Vb] = [Vas]/1.44: https://www.gearslutz.com/board/geekslutz-forum/963114-can-anyone-identify-vintage-speaker-cab.html
GM
Thank you Greg, I will look through these links. That quote of me was my bad wording and sentence structure, sorry. What I meant was I mentioned about some of your MLTL's that I've read about, to the guy that wants to build some cabs for the GPA 604's he wants to purchase. He was recommended the Stonehenge V cab, and I told him to hold off a bit while I dig around and see if I can find some more info on something better, like an MLTL etc.
Would you have any plans all worked out for the GPA 604III for purchase that he could have his woodworker easily build from? This person that I'm inquiring for cannot diy at all, but he has a good cabinet builder. If not would you have any input on Scotts Bison design? I've messaged Scott but haven't heard back on how he thinks it may work for a larger room etc. I think the Bison cab is 290 or 300 liters, so 10.2413 and 10.5944 cubic feet.
Thanks, Dave.
Would you have any plans all worked out for the GPA 604III for purchase that he could have his woodworker easily build from? This person that I'm inquiring for cannot diy at all, but he has a good cabinet builder. If not would you have any input on Scotts Bison design? I've messaged Scott but haven't heard back on how he thinks it may work for a larger room etc. I think the Bison cab is 290 or 300 liters, so 10.2413 and 10.5944 cubic feet.
Thanks, Dave.
Sorry for not having had chance to contribute; currently trying to complete work on a couple of papers & a draft monograph. Even emails have been suffering somewhat. Off to bed now but will go through my records in the morning; it's been a while so I don't want to trust my memory for details.
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