Stonehenge V

Greetings all. I'm a fairly new member to the boards here and I'm the proud owner of some VOTT's I put together with cabs and drivers I sourced through various local transactions. While I love the imaging and realism they offer, I think I'd like to put something together that offers a tad more low-end extension. From what I've gleaned the Stonehenge V might be the ticket. However, that means a list of questions...

Is there a proper drawing anywhere? Would the design benefit from the use of 1" plywood over 3/4"? How crucial is the port placement to the cabinet's performance? Whatever happened to Leonard parts 1 through 5?

Thanks, gang.

I drew up a set of plans for these some time ago - they're not CAD drawings: theyre done by hand. That said, any good cabinet man could make the cabinets from them.

Thanks for the reply. I sent you a PM.

Who knows? Maybe my wife will even say they're not the ugliest things she's ever seen. :)

I have a plan for the Stonehenge I came across some time ago but the file size is too large for me to upload here.
If you want to send me a PM with your email address I can send it to you.
Regards,
John

Hi Todd, would you please send me a copy as well. I sent you a PM, but I don't know if it worked.

Is it possible to front mount a Altec 604E speaker?

Thank you very much in advance.

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Originally Posted by sey

Is it possible to front mount a Altec 604E speaker?

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Yes,but you will have to cut out some slits into the wood were there are those raised ribs on the back of the basket.

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Originally Posted by Altec Best

Yes,but you will have to cut out some slits into the wood were there are those raised ribs on the back of the basket.

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Thanks, I'll try.

You could experiment by clamping a new 30"x42" front baffle onto the front of your VOTTs and see how that works out. Outside dimensions work out to a volume of (Edit; 17.533) cubic feet. You would have to subtract all of the panel thicknesses from that voume to get internal volume, (or about 15 CF subtracting 1.5" from the outside perimeter dimensions).

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Originally Posted by Miko

Greetings all. I'm a fairly new member to the boards here and I'm the proud owner of some VOTT's I put together with cabs and drivers I sourced through various local transactions. While I love the imaging and realism they offer, I think I'd like to put something together that offers a tad more low-end extension.
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I know this is not an answer to your question, but, why don't you just add a sub-woofer to your existing setup? This would be the simplest solution to your problem.

Hi Sey - done.

Greetings All. I have recently retired, and as my first "project" I am going to build my own speakers! I've built a lot of Bottlehead, Audio Note Kits, and DIYHiFiSupply kits over the years, but never speakers. Years ago I had Altec 604-8G speakers in 620 cabinets. Never should have sold them, but we live and learn!

To keep things simple, I'm going to start out with a Duplex speaker--probably the GPA 604-8H-III. I have also seen that a crossover from Selah Audio is highly recommended rather than the stock crossover, so I'll probably contact them too.

As far as a cabinet goes, I think I will either attempt Billfort's cabinet or a Stonehenge V. Todd: if you are still willing to send out cabinet plans, I would be most grateful to receive them. A friend is going to help me build them, since I'm not much of a woodworker. He is a cabinet worker/home remodeler and wants to look at any plans before offering advice.

Looking forward to participating on the Forum, and returning to Altecs!

Dave

hi dave. im pretty new here but i was looking at this link a couple days ago. about the billfort speakers. hope it helps. those stonehenge V plans are a bitch to find.
Billforts Audio Obsession

Hi Dave ! Welcome to the forum ! Try this.It is the Stonehenge III cabinet.Same as the Stonehenge V.The only difference was the drivers.

http://home.earthlink.net/~jmarkwart...iles/3577a.pdf

Thank you. Those are some one of the nicest, clearest cabinet plans I've seen! However, my understanding was that one might want to consider the Billfort and SH V cabinets since in both of them, the drivers were more nearly at ear height, and the internal cabinet volume closer to 9 cu ft (for somewhat lower bass response).

Dave

The Stonehenge is 9 cubic feet. And you can tweak the baffle to raise the driver up higher where you want it and you can also move the port to below the driver..

If my calculations are correct, the internal volume of the SH III is 17.25 x 13.25 x 42.5 = 9714 cubic inches, which is about 5.6 cubic ft. What I don't know is to what degree the smaller cabinet volume will decrease the low end frequency response. Altec's specs for the SH III, however, list the lower end of the freq response to be 50 Hz. If I could get an extra 10-20 Hz lower, I'd prefer that. Having said that, my wife would almost certainly prefer the smaller cabinet!

Dave

Hmm, I thought this cab was the SHV, which IIRC was listed as being 9 ft^3 and the one Todd had the drawings of, or is it an Iconic Manufacturing custom?

GM

Attachment 1954

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Originally Posted by dth31

What I don't know is to what degree the smaller cabinet volume will decrease the low end frequency response.

If I could get an extra 10-20 Hz lower, I'd prefer that.

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As a general rule, the point of diminishing returns is Vas/1.44, though if driven with a high output impedance, up to Vb = Vas is desirable due to the increase in effective Qts and why cabs tended to be relatively huge way back when.

Tuning to Fs is desirable, so with a large enough cab it can often be ~flat in room all the way down due to room's contribution and/or with some form of EQ to trade some efficiency for tonally balancing it.

GM

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Originally Posted by Altec Best

Hi Dave ! Welcome to the forum ! Try this.It is the Stonehenge III cabinet.Same as the Stonehenge V.The only difference was the drivers.

http://home.earthlink.net/~jmarkwart...iles/3577a.pdf

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Not so sure about this. AFAIK the V is larger than the III - I have seen external measurements of 121cm tall x 56cm wide x 45cm deep (47.625" x 22" x 17.75), which would be ~9 cu ft. once you subtracted for internal measurements and bracing. DJK has posted that you get an additional 5hz from the size.

Edit: See the Iconic page - Iconic Speaker Manufacturing - Stonehendge Page

"The Stonehenge Model III - This system consists of a Iconic's new 16"compound loudspeaker, the 704-8A, a custom crossover, and a hand-crafted 6 cubic foot enclosure (interior volume), which gives it excellent frequency response down to 50 Hz. This is an excellent choice for smaller living environments, and systems that employ subwoofers.

The Stonehenge Model V - Our premium system, and the one that has proven to be the most popular. This system consists of a Iconic's new 16" compound loudspeaker, the 704-8A, a custom crossover, and a hand-crafted 9 cubic foot enclosure (interior volume), which gives it excellent frequency response down to 30 Hz. This is an excellent choice where full-range, point-source sound reproduction are desired."

AFAIK the Stonehenge III came with the 604-8G and the Stonehenge V came with the 604-8H...

Iconics are custom I'm pretty sure based on the Stonehenge original plans with some minor tweaks.

I've drawn up some preliminary plans for a larger cabinet with an internal volume of about 9 ft 6 in (before any internal bracing). Briefly, internal dimensions of W 26 in x H 43.5 in x D 14.75 in. This will result in a W 27.5 in x H 46 in x D 16.25 since I will use 3/4 in Baltic Birch plywood all around and will sit the speakers on 1 in spikes, or maybe a 1 in pedestal. The GPA datasheet for the 604-8H-III also recommends 2 round ports of 5.25 in diameter x 2.3 in long ducts, so will try that to begin with, too. Will place the ducts on the back panel approx 16 in above the internal floor, which results in the center of the port being approx 17.25 in below the center of the speaker.

Billfort had remarked in some of his posts that he wanted to keep the front baffle width 26 in, b/c with narrower baffles he felt like he lost some bass. Because my wife was more concerned about keeping the speakers from sticking out too much from the wall, I went with a slightly wider internal width, resulting in a front baffle width of 27.5 in instead of 26 in. I don't think the wider baffle will be a problem, but I'm not really sure, either.

These cabinet dimensions will result in the center of the speaker being 35 in above the floor, which may be a little low since my ears will be about 42 in above the floor. I figure I can always tilt the speaker back a bit if this seems to be a problem. This also leaves 3 in from the edge of the speaker to the top of the cabinet.

If anyone sees any "fatal flaws", or has any comments/suggestions, would be glad to hear about them!

Dave

No such thing as too wide a baffle, only a point of diminishing returns. 30? is normally the minimum unless near a wall or corner boundary before potentially needing any baffle step loss correction [BSC], so if practical, making the cab just deep enough for the driver plus a rear panel mounted brace/cradle to maximize baffle width ?kills two birds with one stone?.

Harry Olson?s circa 1950 tall reflex designed for a home ?high quality? sound system [later marketed as the LS-11] ?taught? me that placing vents up near the driver in a tower alignment isn?t a very efficient use of its high aspect ratio, so recommend the vent[s] be placed closer to the bottom to take advantage of the cab?s ? WL pipe action to provide some acoustic loading to them plus any mid bass notching due to floor bounce will be greatly reduced.

Anyway, the first sim is yours, the second with the vents relocated down 40? from the top and the third is a net Vb = Vas, Fb = Fs MLTL to get the driver up to the desired 42? seated ear height, so 64.5? i.d. tall, WxD = ~331.78?^2, driver down 22.5?, vents down 51.6?, though only baffle thickness [0.75?] long to get the lower tuning due to the additional TL loading.

Spikes not factored in, but an inch either way shouldn?t be audible and if you have a floating floor, the spikes may help.

Regardless, mass loading the cab to the floor is desirable as it can audibly ?tighten up? the bass line, sometimes even with cabs this large, so a large ?hanging gardens? potted plant is a potential tweak with some WAF and the foliage does a decent job of damping spurious reflections off the cab/driver.

GM

Awesome! That's exactly the kind of "education" I was hoping to get. Thank you SO MUCH for the help. I'll factor your comments into the final cabinet size, and report back once I've had a chance to build and listen to them!

Dave

You're welcome! Looking forward to what you wind up with, thoughts on its performance once dialed in.

GM

Forgot to post Olson's 'MLTL' [bummer, it won't display large enough to read]...........

I blew it up a little but by doing so it is a little blurry.

http://www.hostboard.com/forums/hbmc.../2013/04/5.jpg

It blows up fine on other forums, just not this one! I need to add it to Flickr.........

GM

I did.I resized it first and then added it to Flickr and then posted the link [img].

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Originally Posted by Altec Best

I did.I resized it first and then added it to Flickr and then posted the link [img].

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A bit OT - but, you use Photoshop, right AB?

If so, after you resize go Filter menu -> Sharpen -> Unsharp Mask and then in the dialog you can play with the three sliders to get a desired effect.

For line drawings, try something like
Ammount: 228%
Radius: 8.8 pixels
Threshold: 2 levels

But experiment.

After all the support I received here on the board, I thought I should give you an update. My local cabinet maker wanted almost $1800 for cabinets--far more than I hoped it would be. As I was wrestling with what to do, a pair of Model 19s became available in Los Angeles, which I purchased for a reasonable price and picked up myself. So now I'm loving Altec-life again! Thanks again for your support!

Dave

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Originally Posted by dth31

After all the support I received here on the board, I thought I should give you an update. My local cabinet maker wanted almost $1800 for cabinets--far more than I hoped it would be. As I was wrestling with what to do, a pair of Model 19s became available in Los Angeles, which I purchased for a reasonable price and picked up myself. So now I'm loving Altec-life again! Thanks again for your support!

Dave

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Great! Any pics and/or listening impressions of your 19's? How much did you pay/what is their condition/are they all original--if you don't mind me asking?

They look very nice, with no dents in the cabinet, although at least some of the veneer appears to have been replaced. The drivers are all original. The crossover is stock. The grills are in very good shape. I paid $2250.

Although I don't have my old 604-8Gs anymore to compare to, if memory serves (and it probably isn't terribly accurate) the 19s seem better balanced top to bottom. I was never very happy with how the 604s imaged, but even with the 19s up against the wall, the imaging is VERY good. I am VERY pleased with them, and glad I didn't go to the trouble and expense of having new speakers built!

Dave

Attachment 2078

They look to be in nice shape--glad to hear they're all original. I agree with all of your listening impressions--I've found 19's project a great sound-stage--I love mine. I also agree they have a nice flat extended frequency response (depending of course on where you set the two crossover tone controls)--the sound is very "balanced top to bottom" as you put it.....

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Originally Posted by dth31

They look very nice, with no dents in the cabinet, although at least some of the veneer appears to have been replaced. The drivers are all original. The crossover is stock. The grills are in very good shape. I paid $2250.

Although I don't have my old 604-8Gs anymore to compare to, if memory serves (and it probably isn't terribly accurate) the 19s seem better balanced top to bottom. I was never very happy with how the 604s imaged, but even with the 19s up against the wall, the imaging is VERY good. I am VERY pleased with them, and glad I didn't go to the trouble and expense of having new speakers built!

Dave

Attachment 2078

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Quote:

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Originally Posted by dth31

They look very nice.........

Although I don't have my old 604-8Gs anymore to compare to, if memory serves (and it probably isn't terribly accurate) the 19s seem better balanced top to bottom. I was never very happy with how the 604s imaged, but even with the 19s up against the wall, the imaging is VERY good. I am VERY pleased with them, and glad I didn't go to the trouble and expense of having new speakers built!

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Indeed, all that seems missing is the foam horn inserts.

That's because they are, though a properly tuned larger cab and M19 concept XO will tonally balance the 604 to ~match the M19's.

Yeah, the longer the horn and/or the narrower its polar response, the greater its 'throw', so to compare imaging between these two requires a much closer 604 listening position, which of course isn't surprising since it was designed for near-field recording studio apps. My speakers typically position the lead singer/performer ~ in front of the listening 'sweet spot', which is ~15 ft away from the baffle plane 'as the crow flies', causing at least some 'discomfort' to most folks 'raised' on high distortion cone/dome speakers that 'throws' an image mostly behind the baffle plane.

GM

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Originally Posted by gortnipper

A bit OT - but, you use Photoshop, right AB?

If so, after you resize go Filter menu -> Sharpen -> Unsharp Mask and then in the dialog you can play with the three sliders to get a desired effect.

For line drawings, try something like
Ammount: 228%
Radius: 8.8 pixels
Threshold: 2 levels

But experiment.

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No I was using AVS software...

Quote:

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Originally Posted by dth31

They look very nice, with no dents in the cabinet, although at least some of the veneer appears to have been replaced. The drivers are all original. The crossover is stock. The grills are in very good shape. I paid $2250.

Although I don't have my old 604-8Gs anymore to compare to, if memory serves (and it probably isn't terribly accurate) the 19s seem better balanced top to bottom. I was never very happy with how the 604s imaged, but even with the 19s up against the wall, the imaging is VERY good. I am VERY pleased with them, and glad I didn't go to the trouble and expense of having new speakers built!

Dave

Attachment 2078

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Nice score mine are Oak as well... As GM has said the horn inserts (Foam) should be installed.Also if the crossovers are still original they should be recapped.. Replace the resistors and capacitors in them,that's all that needs to be done.Do NOT change the coils/inductors they very rarely go bad.They were done in house at Altec and are part of the voicing.I also had the wires changed from the small single conductor (24-26 awg) to high strand 14 awg. It made a huge improvement in mine !

Thank you all for the comments and advice. Replacing the internal wiring, caps and resistors is on my "to do" list, but I've been enjoying them so much it's going to have to wait for a bit!

Dave

Trust me Dave you will Love the improvement ! Also you need to do the ground bypass Mod if they were built before Altec redesigned the wiring.. Last pic.

http://www.hostboard.com/forums/hbmc...2.jpg~original

http://www.hostboard.com/forums/hbmc...3.jpg~original

http://www.hostboard.com/forums/hbmc...4.jpg~original

http://www.hostboard.com/forums/hbmc...5.jpg~original

http://www.hostboard.com/forums/hbmc...6.jpg~original

http://www.hostboard.com/forums/hbmc...7.jpg~original

http://www.hostboard.com/forums/hbmc...8.jpg~original

In the last photo there is also a ground wire that goes from lug 2 to 4 that isn't highlighted.It runs right under the yellow wire if you look close you can see it.