Hrmmm...
I'm thinking that a 55Hz response floor is what's in order. But the WA factor demands I keep my box under about 12.5 litres. Some cursory number crunching on some of the resources I've been put on to with this thread suggest I simply cannot achieve a low enough frequency range given the size restrictions. Which is sad, but I'll still have those peerless' for my Mk.3 speakers.
So in order to make my TL mini-monitor dream come true I need to find a new, much more suited driver I think.
What values should I look for in the TS measurements for a small woofer to deliver desired bass from such a small box?
I'm thinking that a 55Hz response floor is what's in order. But the WA factor demands I keep my box under about 12.5 litres. Some cursory number crunching on some of the resources I've been put on to with this thread suggest I simply cannot achieve a low enough frequency range given the size restrictions. Which is sad, but I'll still have those peerless' for my Mk.3 speakers.
So in order to make my TL mini-monitor dream come true I need to find a new, much more suited driver I think.
What values should I look for in the TS measurements for a small woofer to deliver desired bass from such a small box?
I can do small-footprint floorstanders... As long as I keep the box small in length and width, then I can apply height. (I just had my my wife explain exactly what is and isn't allowed in the living room)
Would it be sensible to take some of cloth ears' revised designs and just expand them out to about 85cm in height?
Would it be sensible to take some of cloth ears' revised designs and just expand them out to about 85cm in height?
raypalmer said:
They were more to tickle fwater's imagination when he's modelling your driver in a TL (I'm not sure what he's using). The driver in question does appear to need a bit of volume when in a sealed or BR enclosure.
But, with your original sizing 0.66m x 0.28m (assuming they are external dimensions) x 20cm (assuming this is an internal dimension) gives a volume of 32 litres. take away any bracing and the volume of the driver and you've probably got about 29 litres. When you look at 'unstuffed' sims, this is a sealed Qtc of 0.685 (good). And the same sized box (including a 3"dia port of 5.3" length) gives good response - if having a 2dB raised output around 75Hz (which is not necessarily a bad thing).
If that size box is OK with SWMBO, then you might very well be able to put in a TL. If the box is too small, then a TL won't have a chance to work properly and I think it starts to act like a too-small aperiodic enclosure (others will know more). Small foot print floorstanders would probably work also.
Some advice, consult on the finish. Paint it black is OK for some, and others love a good hearty burl veneer - but treating it as a bit of living room sculpture is worthwhile. My bass bins are Tasmanian Oak wood-veneered (which is pretty much a generic name for 'light-coloured wood') and my mains are light Cherry wood-veneer. It's amazing what you can do if it matches the decor.
Can't wait for fwater's results!
raypalmer said:
Hmm, a T/S max flat alignment is around 47 L/42 Hz, so by the time you shrink it down to 12.5 L there's a ~3 dB bump in the mid-bass and the bass is MIA. Tune it higher and the bump increases. Make it ~aperiodic and you have a mids driver, so yeah, a different driver is in order and to hit your 'marks' with a TL you'll need one with a 4.87 L Vas, 55 Hz Fs and 0.403 Qts. Maybe B@$3 has a replacement Wave Radio driver that will work.
GM
GM said:
Greg,
There is a whole series of boxes that are variations on the volume and tuning of the FonkenPrime. The FS isn't quite as refined sonically as the FonkenPrime, but is the easiest to build, has a very small foorprint, and does not require a stand.
Althou those who tell me that the Fonken fits within the parameters of an "official" Onken (ie you can plug it into the spreadsheet) that is not how i developed it, basically taking only the physical configuation of the ports for their inherent panel stiffness and that they fullfilled my goal of a port with highish rsistance.
Other boxes, based on the original box sizing and half-inch ply construction. External dimensions 66cm (h) x 28cm (d) x 22.5cm (w).
Box 1 - slot ported bass reflex. Slot port is 2cm high, 17cm long, and runs the full width of the speaker box. f3 <45Hz. Includes some 'spare' space for bracing the box internally. Front firing port (so it can sit close to a wall - literally on a bookshelf).
Box 2 - round ported bass reflex. Port is 2-inch (5cm) pipe and 3 inches long. f3 <45Hz. Includes some 'spare' space for bracing the box internally. Front firing port (so it can sit close to a wall - literally on a bookshelf).
Box 3 - sealed enclosure. f3 ~70Hz. Includes some 'spare' space for bracing the box internally. Simplest to build.
These are all modelled without stuffing. Extra stuffing would probably need an extra cm port length for Box 1, half a cm on Box 2 and no change for Box 3.
More options for your Peerless'! Was that original box size OK with the Mrs?
Box 1 - slot ported bass reflex. Slot port is 2cm high, 17cm long, and runs the full width of the speaker box. f3 <45Hz. Includes some 'spare' space for bracing the box internally. Front firing port (so it can sit close to a wall - literally on a bookshelf).
Box 2 - round ported bass reflex. Port is 2-inch (5cm) pipe and 3 inches long. f3 <45Hz. Includes some 'spare' space for bracing the box internally. Front firing port (so it can sit close to a wall - literally on a bookshelf).
Box 3 - sealed enclosure. f3 ~70Hz. Includes some 'spare' space for bracing the box internally. Simplest to build.
These are all modelled without stuffing. Extra stuffing would probably need an extra cm port length for Box 1, half a cm on Box 2 and no change for Box 3.
More options for your Peerless'! Was that original box size OK with the Mrs?
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