Idle musings

Dedicated to those large boxes at one end of the room
Ant
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#1 Idle musings

Post by Ant »

An idle musing on a biiiig sealed box speaker.
Im lucky in that i can accommodate a pair of cabs the size of a fridge, so i got to thinking of a speaker using my pair of fane 15-300tc's, and a pair of fane 15-400lf to fill in the bottom end abit and provide abit more of a punch.

The tc's have proven quite adept finesse and sounding effortless, and at 101db efficient, doing so at a whiff of throttle.

The 15-400lf isnt so efficient at 96db/1w, but i dont think that would matter too much as at the frequencies im looking at as the tc has a rising response, and isnt far off in terms of db at the same low frequencies.

I know bugger all about speaker design though, so wether thats viable or not is another matter...

Intersting thing is to see what could be done if the shackles were released in terms of cabinet size, everything seems to be geared towards little thin tall speakers these days..
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JamesD
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#2 Re: Idle musings

Post by JamesD »

Its one hell of a box to get that driver down low...

For a reflex box SC4 alignment. 670l!!!!!
F3 24Hz small peak about 0.3dB. F12 20Hz so it fall off a cliff!
20cm port dia - realistically two 14 cm diameter ports 4 cm length
About 93dB/W efficency so they will need a bit of power to match the tc.

By contrast a sealed box is optimised at
415l for Qtc 0.707 for f3 48Hz f12 26Hz
About 93dB/W efficency so they will need a bit of power to match the tc.

Another damn big box...

It might be better to look at the SB Acoustics SB34NRX75-6 driver as a mono single sub. The driver cost would be the same as two Fanes but it would give you a 100l box with 33Hz f3 and 18Hz F12 so gentle roll off at Qtc=0.7 Sensitivity is about 89dB/W so it needs a bit of power but use a 85Hz crossover to your main speakers and you wouldn't notice the mono bottom end and it can be driven by an inexpensive class d amp...
Ask Simon how this works as he uses it...

Fun to speculate!

J.
Ant
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#3 Re: Idle musings

Post by Ant »

Ha!
They would really be a massive pair of cabs, i could hire them out to the local bands!
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simon
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#4 Re: Idle musings

Post by simon »

It'd change your world Ant :-). Actually, it might. The affect of good deep bass transformed a lot of music for me. And it's great for watching films too. Get a £5 class D 3116 subwoofer amp from eBay (sums both channels to a single output) and a £10 "Meanwell" type LED psu, and a 85Hz lowpass filter, and you're good to go.

What really surprised me was that having bass that I can control the volume level of independently means I listen quieter than without - a simple loudness filter.
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Ali Tait
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#5 Re: Idle musings

Post by Ali Tait »

Yep say the same with the Bastanis- I use a Behringer inuke 3000w DSP amp for the bass which I find works very well. It’s easy to dial in the bass by ear with tracks you know well- at least the measurements at Marks’ seem to show that. Also good for turning up a notch or two for films- some serious bass on tap!
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#6 Re: Idle musings

Post by Ali Tait »

simon wrote: Sun Dec 06, 2020 6:07 pm It'd change your world Ant :-). Actually, it might. The affect of good deep bass transformed a lot of music for me. And it's great for watching films too. Get a £5 class D 3116 subwoofer amp from eBay (sums both channels to a single output) and a £10 "Meanwell" type LED psu, and a 85Hz lowpass filter, and you're good to go.

What really surprised me was that having bass that I can control the volume level of independently means I listen quieter than without - a simple loudness filter.
Actually I find that too Simon, the bass available was a real ear opener for me, even more so hearing Vic’s creations, never heard bass like that in a domestic setting.
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#7 Re: Idle musings

Post by JamesD »

Agree with that point too - I listen at a lower level when I use the sub-woofer too... and it seems to make micro dynamics better as well as macro dynamics and it improves rhythmic contrasts - for instance it makes the difference between drum machine drums and human played drums more obvious with the human played drums being much more involving than drum machine drums...
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Greg
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#8 Re: Idle musings

Post by Greg »

Surely, drum machine drums are also human played? I believe the difference is between real drums and the electronic equivalent drum pads. Is that right or am I completely mistaken?
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#9 Re: Idle musings

Post by simon »

It's kind of like adding range at the very bottom gives everything higher up more space. Curious really. I reckon a 20Hz to 40Hz sub to go below the Supravoxes would be great. Quite what would have the speed and tone to match I don't know though.
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#10 Re: Idle musings

Post by Ant »

Hmmm.
I have here sat doing nothing, a pair of 12" drivers that have been doped, the specs are unknown, but when a frequency generator was stuck on them and a tone put through them, the resonant frequency was 45hz ( an orange pip was put on the driver, and it went barmy when it hit 45 hz)
I also have a samson servo 270 studio amp with independent l/r volume controls.
If i wanted to faff with an active solution....
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JamesD
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#11 Re: Idle musings

Post by JamesD »

Hi Greg,

Here is wiki statement on drum machines
I was referring to the machine generated patterns that maintain a constant beat - a human drummer speeds up and slows down their beat pattern whilst paying within the time signature to accentuate the feel of the track.

This is illustrated in this youtube video where time signatures can also be quantised and recorded drum tracks brought into strict alignment with the time signature..
- it kills the life in the track

Sorry if this was what you were referring too and I got it wrong.

ciao

James
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#12 Re: Idle musings

Post by chris661 »

Ant wrote: Sun Dec 06, 2020 11:16 am An idle musing on a biiiig sealed box speaker.
Im lucky in that i can accommodate a pair of cabs the size of a fridge, so i got to thinking of a speaker using my pair of fane 15-300tc's, and a pair of fane 15-400lf to fill in the bottom end abit and provide abit more of a punch.

The tc's have proven quite adept finesse and sounding effortless, and at 101db efficient, doing so at a whiff of throttle.

The 15-400lf isnt so efficient at 96db/1w, but i dont think that would matter too much as at the frequencies im looking at as the tc has a rising response, and isnt far off in terms of db at the same low frequencies.

I know bugger all about speaker design though, so wether thats viable or not is another matter...

Intersting thing is to see what could be done if the shackles were released in terms of cabinet size, everything seems to be geared towards little thin tall speakers these days..
2x15"s a side would be pretty impressive for a domestic-sized system. If you're looking for some more "punch", though, would it be an option to apply a BSC-style filter? Shelve down the mid-high range a bit, and allow the bass to come through.

It'd throw away a couple of dB of sensitivity, but it's pretty amazing what a couple of dB here and there (over a fairly broad frequency range) can do to our perception of the sound.

As always, though, I'd start with some measurements and see what's what. The lack of "punch" might be a hole in the response somewhere in the 80-160Hz octave, and adding a couple of woofers may or may not fix that.

Chris
vinylnvalves
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#13 Re: Idle musings

Post by vinylnvalves »

Before.. seeing the light and embracing the DSP. I used some passive line level crossovers successfully. This allows you to feed power amps with the right frequency bands. You could put in a low level filter and keep what covers you have in the speakers the same, they just won’t see signals below what ever x over you choose, so should clean up the midrange too. https://www.t-linespeakers.org/tech/fil ... eHLxo.html
I had a passive preamp with 2 sets of outputs and put the covers in the preamp box. I did try some LR filters, but at low freq the inductors are quite large.
I have some ferrite bobbins if you wanted to wind your own, see https://www.marchandelec.com/xm46-pllxo.html
vinylnvalves
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#14 Re: Idle musings

Post by vinylnvalves »

Xovers not covers...bloody spell checker
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ed
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#15 Re: Idle musings

Post by ed »

Re d(r)um machines as mentioned by Greg and James:

My experience over the last 30+ years are that drum machines have evolved. All the drums I have used when not using a live drummer have been sampled from live played patterns and included via midi. There are a gazillion patterns already out there that can be used and if they are not adequate you can play midi drums in real time via an electronic kit which will score them for you. You can also play via a standard midi keyboard if you don't have an electronic kit.

I use and have used a plug in synth called 'session drummer' which is old hat now but from the off allowed quantization(alignment in time) or randomisation to mimic real drummers wayward timing.

There is no such thing as boring with modern fake drumming, and to date I've never met anybody that can tell the difference. Historic recordings are entirely different though...ymmv as always.
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