Santana 1 Altec Project Advice

[hmolwitz]

I scored a set of 515-8g and 299-8a drivers and a matching crossover, and I am attempting to insert them into a set of Santana 1 non-ported cabinets.
When I punch this into (I pushed down the volume to allow for the HF an a Horn) unibox I get this which seems fine.
file:///C:/DOCUME%7E1/HARRYM/LOCALS%7E1/TEMP/moz-screenshot.jpghttp://images.andale.com/f2/117/107/6383143/1129959725034_VB_Response_Altec_515_8g.gif

I ran horn calulators to create the horn for this HF unit, but I would like to know if there is anything off the shelf in a small form factor which could be easily adapted. This is a 1.4" driver.
These are the contours.
Tractrix Contour for Horn



Distance Radius Square Area Contour Width

0.0 1.8 3.1 9.9 0.3

1.0 2.1 3.7 13.5 0.5

2.0 2.4 4.3 18.3 0.6

3.0 2.8 5.0 25.3 0.8

4.0 3.3 5.9 34.9 1.2

5.0 4.0 7.0 49.4 1.6

6.0 4.8 8.5 72.2 2.4

7.0 6.1 10.8 117.5 3.9



Exponential Contour

Throat = 9.9308, fo = 800.0, sizeFactor = 1



Distance Radius Area Contour Width

0.0 1.8 9.9 0.3

1.0 2.1 13.3 0.4

2.0 2.4 17.8 0.6

3.0 2.8 23.9 0.8

4.0 3.2 32.0 1.1

5.0 3.7 42.8 1.4

6.0 4.3 57.3 1.9

7.0 4.9 76.8 2.6

8.0 5.7 102.9 3.4

9.0 6.6 137.8 4.6

10.0 7.7 184.6 6.2

This is my first attempt at anything at all like this, I was going to flog these drivers on Ebay, but was advised that I would probably never get my hands on anything like these again so I should make a serious attempt to listen first.
I am trying to keep the size down.
Currently running Dalquist DQM 9 and Bose 1800 Amp off my computer .

[hmolwitz]

Lets try this
http://images.andale.com/f2/117/107/6383143/1129959725034_VB_Response_Altec_515_8g.gif

[speakerdave]

I think I saw a suggestion somewhere in all that data that your choice of crossover frequency is 800 Hz. The smallest Altec horn I am aware of that will mount the 1.4" driver is the 511E. It is like the 511B except that 1) it has the 1.4" throat opening; 2) it has a thick external coating of aquaplas which dampens it quite effectively; 3) the joining welds of the mouth webs have been replaced by (I think) aquaplas; 4) whereas the 511B is nearly ubiquitous the 511E was produced in small numbers and is quite hard to come by.

If you are handy with metal fabrication you might be able to modify a 511B throat and apply external damping and grind out the throat webs and replace with something rubbery. I know the dampening measures have often been carried out by people using the 511B with 1' drivers.

The next size up I believe is the 805 which is made with a detachable throat so that a special throat mounting two drivers can be used. Jammin Jersey has some with single-driver throats for $500 EACH.

There are many 1.5" horns (and some 1.4") available from other manufacturers, but I'm not specifically familiar with any of them. One of the forum members has in the past reported good results with DDS horns. They certainly make a large variety. I don't think they are inexpensive. Here is their website URL:
http://www.ddshorns.com/content.php?page=home

You could also explore custom-made wooden horns. Here is the Martinelli URL: http://www.woodhorn.com/

David

P.S. I can sell you a pair of 511E's, NOS in a factory box with an envelop of mounting hardware, but they won't be cheap. Send me a PM if interested.

sd

[Cyclotronguy]

Speaker Dave,

511B's can absolutley have the driver mounting flange cut off and a new one welded on to fit 1.4 inch throat drivers.

Cyclotronguy

[spkrman57]

I have a pair of them, they are aquaplas coated and don't ring like the 511/811 series.

Downfall if the 60 degree coverage compared to the 511/811 90 degreaa coverage.

They were made for the 288/290/292/299 series AFAIK!

Ron

[speakerdave]

Yeah, those will work, but I think he's looking for small.

David

[speakerdave]

511B's can absolutley have the driver mounting flange cut off and a new one welded on to fit 1.4 inch throat drivers.
I believe it could be done, yes. Lessee, now where was that cutting torch?

David

[hmolwitz]

Thus far they are all on the large size for what I was considering, I emailed the folks @ DDS, and I will see what they have to say.
I wanted to flushmount the horn in the cabinet and for phasing I am supposed to align the drivers which gives me about a 5" depth after remeasuring to the base of the dust cap from the face of the baffle.
The horn should provide acoustic coupling to the driver and enough dispersion to prevent beaming.
Am I outside the realm of reality in this attempt?
Or should I just attempt to roll my own from the horn calculator?
Altec did this sort of thing in speakers like the model 14, but as far as I can tell they always user a 1" compression driver.
As far as the crossover, I may need to go three way as this driver doesn't seem to go past 16,000 HZ, though my hearing may not warrant it.

[speakerdave]

Thus far they are all on the large size for what I was considering, I emailed the folks @ DDS, and I will see what they have to say.
I wanted to flushmount the horn in the cabinet and for phasing I am supposed to align the drivers which gives me about a 5" depth after remeasuring to the base of the dust cap from the face of the baffle.
The horn should provide acoustic coupling to the driver and enough dispersion to prevent beaming.
Am I outside the realm of reality in this attempt?
Or should I just attempt to roll my own from the horn calculator?
Altec did this sort of thing in speakers like the model 14, but as far as I can tell they always user a 1" compression driver.
As far as the crossover, I may need to go three way as this driver doesn't seem to go past 16,000 HZ, though my hearing may not warrant it.
The state of my apprentice understanding on all this at the moment is this: The horn length, the relative positions of the driver acoustic centers, the crossover frequency, the crossover type and the psychological tolerance for misalignment are all one package and should be considered together. For example. if you want the benefits of aligning the acoustic centers of the drivers you should probably use a crossover that does not introduce phase shift. Also, psychoacousticly a given offset of woofer and midrange/treble driver may be OK at 500 Hz but intolerable at 1200Hz. Studying designs that have been regarded as successful can show you that good speakers are the product of judicious compromises. The JBL K2 M9500 (some people consider this JBL's best speaker so far), for example, uses a rather deep horn, but its woofers are baffle mounted; the crossover frequency is 650 Hz. In considering that horn with a higher crossover point in an early proposal for the Project May speaker system, the engineer who designed the M9500 strongly advised against it. The Altec Model 19 crossed over at 1200 Hz uses a baffle mounted woofer and the 811 horn with a straight- forward 2-pole crossover. Many may consider this an explanation for their dislike of the speaker, but many others think the speaker is just terrific. The Altec A7-500 (the crossover point) basically uses aligned drivers, but also uses a 2-pole crossover that introduces 180 degrees of phase shift; some of these characteristics apparently offset each other to a very listenable speaker.

I'm suggesting that A) It's safest to copy as exactly as possible an engineered system, or B) get some real good technical advice on a custom arrangement, and C) do not valorize one technical parameter over all the others related to it as if the one will by itself yield perfect results.

On another point, I think the shortest horns at any given frequency are Dr. Edgar's salad bowl tractrix horns. However, I've read that they tend to be beamy at higher frequencies and therefore yield a rather small sweet spot.

The value of reproducing the frequencies above the ones that are specifically audible is a matter of debate. Personally I would not let the lack of anything above 16kHz interfere with my enjoyment of Horowitz at Carnegie Hall.

David

["Duke" Spinner]

and then there's the K-Horn

a veritable mess of delays .......esp the bass horn

but it still sounds ok

[hmolwitz]

I was reading another post here on how to phase align the horn, and it involved miking the speaker into a scope and looking for the peak or reversing phase and looking for a valley and adjusting the position of the horn.
The crossover was pulled from an A7 type cabinet so I believe the drivers were aligned in the vertical plane.
Is there a source for those Edgar salad bowl horns?
I haven't been able to find those yet.
Thanks
Harry

[speakerdave]

I believe Dr. Edgar makes them himself or has someone do them for him. I don't think he has a website, but I believe if you keep searching on the web you will find in one of the many discussions of his work a posting of his email address.

If you have a lathe you could make them yourself using one of the various horn calulators available on the web. Those Altec 299 drivers have exponential expansion built into the throat. I'm not sure what the transition should be like from exponential to tractrix. I think some people ignore this issue, but other's see it as potentially a problem.

David

[spkrman57]

Not sure if this is pertinent or not. I use Bruce Edgar's 500hz horns with 1.4" 399 drivers from Great Plains(similiar to 288-8K Altec's).

Bruce takes orders by e-mail or phone(I prefer phone as sometimes the discussions can be very interesting - not to mention way over my head).

Bruce will take some time to deliver the goods, but worth the wait as I have ordered several horns from him over the years. Expect a 3 or 4 month turn-around time for orders to arrive.

My 500hz horns ran me $400.00 for the pair(unfinished poplar).

I like the round wooden tractix horns, most don't due to beaming if you can't sit in a dedicated sweet spot, or can't get far enough away from them to alleviate that problem. But I really think a round horn expands evenly in the vertical and horizontal pattern.

Ron

[hmolwitz]

I am going to attempt to lathe my own wish me luck.
Harry

[speakerdave]

'Way to step up to the plate, there, Harry. Good luck with it.

David

[hmolwitz]

I am glueing up the blocks, I hope to hit the lathe tomorrow, I went with poplar as it is not expensive and should be relatively easily worked.
I may just top mount them as the drivers are heavy.

[hmolwitz]

I failed miserably with the lathe, but failed to injure myself seriously, and found some lovely posts here on Smithhorns and decided to have at that instead.
I built a 1200 hz and mounted it to a 34654 throat I had, and it sounds nice.
Unfortunately I wasn't able to locate another of these throats, so I am still at it but very slowly.
pics (http://images.andale.com/f2/117/107/6383143/1135668990754_PICT0021.JPG)
pics (http://images.andale.com/f2/117/107/6383143/1134798979751_PICT0025.JPG)

(http://%20http://images.andale.com/f2/117/107/6383143/1132517104670_PICT0023.JPG)