Doc mod 3 way with upward firing mid ?

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karatestu
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Doc mod 3 way with upward firing mid ?

Unread post by karatestu » Thu Mar 02, 2017 6:21 pm

It just occurred to me today that maybe I could fire the mid upwards with my 3 way Marantz imperial 7 project. This would be like cubes but with a 12" woofer at the bottom of the baffle and a much larger cabinet. Tweeter would be at top of baffle as usual.

Would this work ? As a new baffle is being made anyway this would not be a problem.

Thanks Stu
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Dr Bunsen Honeydew
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Re: Doc mod 3 way with upward firing mid ?

Unread post by Dr Bunsen Honeydew » Thu Mar 02, 2017 6:44 pm

I don't know, the only similarity was with the Linn Isobarik, with mid and tweeter on top as well as front. I think you can say the Isobarik was an acquired taste.

Go for it and tell us how good if you wish to experiment and try something new. This is the point of the exercise, if you can take the concept further on from me I would be very content. Already we have Steve the Shadow with a variation which is attracting much attention at audio talk.

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karatestu
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Re: Doc mod 3 way with upward firing mid ?

Unread post by karatestu » Thu Mar 02, 2017 8:19 pm

Cheers doc.

I know it does not keep the bass in phase with the floor like the cubes but i thought it may help with integration between mid and tweeter.

I might build rough cabs out of some old chopboard i have laying around to test this concept. It would be a shame to cut a hole in the top of the marantz cabs if it does not work. Might make a back box for the mid too.

Stu
Naim, Linn & Harbeth fanboy

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Dr Bunsen Honeydew
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Re: Doc mod 3 way with upward firing mid ?

Unread post by Dr Bunsen Honeydew » Thu Mar 02, 2017 8:30 pm

The mid doesn't need a back box, just series wire with the bass driver.

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karatestu
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Re: Doc mod 3 way with upward firing mid ?

Unread post by karatestu » Thu Mar 02, 2017 8:50 pm

Dr Bunsen Honeydew wrote:The mid doesn't need a back box, just series wire with the bass driver.
Oh, okey dokey. Forget that one then, saves me a job :grin:

Not enough room to put the bass driver firing up which is a shame.
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karatestu
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Re: Doc mod 3 way with upward firing mid ?

Unread post by karatestu » Sat Mar 04, 2017 11:14 pm

I have been looking around on the tinternet at speakers with side firing bass drivers. There are quite a few examples out there including models from Rega :roll:

According to several sources (could be bullshit) this way of doing things can have several advantages.

1) Out of band high frequency information is attenuted so providing a first order filter for free (i.e not electrical)
2) Baffle width is reduced to width of mid driver therefore increasing WAF factor and reducing diffraction effects.
3) There are more positioning possibilities as bass drivers can be either both facing outwards or facing inwards.

Might be worth an experiment. Side firing bass, up firing mid and forward firing tweeter. Just a pity the Marantz cabs are not deep enough to accommodate a side firing 12".

Stu
Naim, Linn & Harbeth fanboy

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karatestu
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Re: Doc mod 3 way with upward firing mid ?

Unread post by karatestu » Wed Sep 13, 2017 8:55 pm

I gave up on the side firing bass driver as i could not be arsed to go through yet more prototyping. Maybe one day.

I am however nearly finished with my 3 way semi omni. 12" bass in original cab firing forwards and a experimental small cab with forward firing tweeter and upward firing mid driver. A little twist on the usual doc mod project and cubes for that matter.

If succesful i will either put the mid and tweeter in the original marantz cabs or make a small cubette type cab to go on top of the original cab. I have some rather nice 2" diameter brass and stainless steel solid round bar which might be good to go between main cab and small cube. Could also use this round bar to make stands.
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