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Multi-Way Conventional loudspeakers with crossovers

Recommendation for DIY Altec A7 cabs
Recommendation for DIY Altec A7 cabs
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Old 30th April 2016, 08:54 PM   #1
philajoe73 is offline philajoe73  United States
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Default Recommendation for DIY Altec A7 cabs

Built a 2/3 scale reproduction of A7 cabinets designed for 10" drivers. Horn is a Heil AMT transformer with an extended waveguide. This project has been assembled from items I have accumulated, so not a big budget production. Nonetheless, I did pay careful attention to the plans I found online and am proud of the outcome. Problem is that the only 10" drivers I have are lower quality and designed for sealed cabinet. I have a 2 LR crossovers built for 1200Hz and 1500Hz that I have tried, but the mid-bass seems muddy and I suspect it is due to the driver not liking the vented design.

Any recommendations for a mid-bass that won't break the bank, yet provide better clarity? Amplifiers are in the 25W range.

TIA
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Old 1st May 2016, 03:38 PM   #2
philajoe73 is offline philajoe73  United States
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Default bump

any ideas?
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Old 1st May 2016, 05:58 PM   #3
Eldam is offline Eldam  France
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Let's try...

The genuine design was made with a the 16" Altec 416-8B if I'm correct : it has a low resonance frequency but the cabinet didn't allowed to go lower than F3 80-60 Hz, maybe a little less in some rooms. So you must choose something close in the T/S parameters. Could a 2/3 sized cabinet will match is an other story, the load should match the driver you choose !

The Heil 1 is better upon 1k6, but maybe your horn will allow to us it lower : measurement will tell you !

The game with the FLH of the cabinet and the one designed for the AMT should be a smooth transition at the XO...

As for the wood : a thicker or another wood will not give you surely a better result !

Trained designers or experienced guys with the genuine A7 will have more accurate inputs !
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Old 1st May 2016, 09:12 PM   #4
philajoe73 is offline philajoe73  United States
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Default Altec reproduction

Thanks, Eldam. I am beginning to see the lower end limitations you mentioned. I really wasn't looking for the earth to shake with this enclosure, but I find that I am having to heavily equalize for the bottom end to compete with the Heil. I know that the efficiency mismatch is causing a lot of this and my intent was to bi-amp this setup to overcome any mid-bass limitations. My hope is that there is a 10" driver better suited for this setup.

BTW, I couldn't be happier with the add on horn. Thanks to Jeff Poth for his inspiration. The AMT has always impressed me in whatever design I hear it in. They really are easy to work with and this modification seems to make it even more versatile.
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Old 1st May 2016, 09:17 PM   #5
Zen Mod is offline Zen Mod  Serbia
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Recommendation for DIY Altec A7 cabs
what's origin of that AMT WG ?
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Old 1st May 2016, 09:59 PM   #6
philajoe73 is offline philajoe73  United States
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Default Heil waveguide

A variation on this: Heil AMT1 And The Heil Horn Article By Jeff Poth

His design a is a bit more complex. I was just aiming a some improvement to an otherwise awesome driver.
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Old 1st May 2016, 10:06 PM   #7
Zen Mod is offline Zen Mod  Serbia
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Recommendation for DIY Altec A7 cabs
thank you
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Old 1st May 2016, 10:26 PM   #8
Eldam is offline Eldam  France
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Some thoughts : you should use an active design to save money because it is hard to find the correct XO and slope : a 2 way MiniDSP may save your wallet ! And also allow to apply some EQ as making bi-amp easier !

You have also the possibility to tune the "port" with a moving piece of wood to close more or less this apperture in relation to your room !

Cabinets looks very nice

There are nice 10" Beymas or B&C drivers, Maybe JBLs are easier to find where you live ?

Last edited by Eldam; 1st May 2016 at 10:28 PM.
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Old 1st May 2016, 10:32 PM   #9
philajoe73 is offline philajoe73  United States
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Default miniDSP

I just started exploring this product and it looks very interesting. Do you have any experience with it? Curious to know if it will work well with tube amplifiers.
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Old 1st May 2016, 10:36 PM   #10
philajoe73 is offline philajoe73  United States
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Edlam, please forgive me; thank you for the compliment! I have a tendency to focus on technical details!
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