Ultimate Open baffle for tannoy red 15 inch

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Out of curiosity, why 80 hz? I have played around with my father's 15" reds in an open baffle but I was not expecting to go anywhere near that low. What were you thinking of for the below 80hz?

I don't have room for a suitably sized box.

ray
hi
how low were you able to acheive?
I want as low as possible, and 80 hz its the point where I feel that its okay 80 hz without sub, but i it cant go to 80hz, I will need to get a sub also...
 
I got nowhere near 80hz, probably more like 200. But my baffle was only about 20" wide and 36" high. My wife has a say in this and huge baffles are out of the question.

I tried a slot loaded dual 10" woofer arrangement and it seemed to mate ok but nothing wonderful. I am no expert with this stuff.

You should try working with the Edge program to get a sense of how low you can go with various sized open baffles and look at some of the other posts about using 15" speakers on open baffles.
Home of the Edge

If you read the Martin King pages you will find that the low QTS of 0.26 for your Tannoys is not ideal for very low frequencies.
OB Theory

ray
 
hi everyone. I will build a open baffle for my dad.
please recommend me what open baffle I should do if I want the bass to go down to 80 hertz...

cheers
Why? in a Very poor Box enclosure (most anything). that driver will hit ~40Hz, even on lo quality electronics.. it's fs is in the 20's IIRC.
With a 1khz crossover point to the horn section, what's the point of an OB unless you favour large sheets of plywood.
 
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I would look at the Qts of a 15" Tannoy and look at typical recommendations for Qts in successful OB builds and conclude that this 15" Tannoy does not suit OB loading.
The low Qts of the big Tannoys suits box loading, not the sealed variety, the vented style. Tannoy specifically mention this in their literature.

A big vented box suits the high efficiency big Tannoys down to a T.
Try a 200Litre box tuned to ~ 30Hz to 35Hz. It plays deep and loud. But excessive excursion below resonance must avoided. You will tear surrounds if you overdrive with VLF.
 
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EQ it. It'll go as low as you like, but maximum SPL will be severely compromised.

I suspect that, no matter how big the baffle (unless it becomes effectively infinite) is, you won't get satisfactory low end out of this driver.

It is meant for enclosures that will reinforce the low frequencies. You're attempting to put it on an OB, which loses LF.
It isn't going to work, unless you throw some power at it.


Alternatively, save yourself some money on plywood, and get an Eminence Beta 15 per side, in addition to the Tannoys. Put a big inductor in series with the Eminence, get it as near to the floor as you can.
I'd recommend against the Alpha 15 (commonly used on OBs) as I'm yet to hear it sound as good as a closed-box system - the Beta 15 is a better driver.

Chris
 
Hi,

Wise move. Its the wrong driver for an open baffle, go big low vented.

Wide and not that deep will go far lower and louder than open baffle.

1-029-029301-Tannoy-Super-Red-Monitor-SRM-15x.jpg


A near "ultimate" cabinet for a 15" Red.

rgds, sreten.
 
Chris661, how do you setup the inductor on the Beta 15? What values?

TIA!

I think this is it.

The HF unit was a FR driver of some sort - think it was ~6" diameter, but I don't know make/model. Its a series crossover, so it'll be fairly tolerant of switching different drivers in.

seriescrossover002.jpg


I remember looking at the inductor thinking "that's a big 'un".

Sounded pretty good, anyway. Certainly one of the best OBs I've heard, but I still prefer boxes.

Chris
 
Here's what one of my tech buddy thinks is ideal for the tan 15"..

"Ideal" cabinet for the speaker, along with resulting characteristics would be the following:


- Cabinet volume: 2.95 cubic feet
- Minus 3 db point: 54.8 Hz
- Cabinet resonant frequency: 45.2 Hz
- With a port area of 25.13 square inches (2 X 4" pipe), port length would be 7.11"
- Peak at resonant frequency: 2.33 db


Cabinets are seldom calculated for ideal dimensions for various reasons; either the volume would be unacceptably large, or the resonant frequency too high. In our case it is the latter, and it is probably for that reason that they decided to make the cabinet larger in order to lower it. The compromise being a larger peak that would give the impression of an extended low end response at the expense of damping.




So now, for the 12.5 x 23 x 32" inside dimensions cabinet you now have:


- Cabinet volume: 5.32 cubic feet
- Minus 3 db point: 42.5 Hz
- Cabinet resonant frequency: 38.4 Hz
- With a port area of 25.13 square inches (2 X 4" pipe), port length would be 4.5"
- Peak at resonant frequency: 5.35 db


So basically the cabinet you have extends the low frequency response by approximately a third (in musical terms), but the tuning peak will be almost exactly 3 db higher, or twice the acoustic intensity, and the overall low end response would be a bit "softer" because of the higher Q factor (lower damping of the speaker).

What do you guys think.
 
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