Update - more bass required
OK, so my 10.3's are finished. As are the Ikea salad bowl project with the tiny Alpairs, that sound simply amazing.
When I was last stateside I bought a subwoofer plate amp for the little Alpair 6's in salad bowls. However for nearfield listening they don't need any more support - amazingly!
However, I am missing some extra bottom end for the 10.3's. WAF has fundamentally ruled out Pensil enclosures, so I am now looking into the possibility of adding a sub with plate amp, crossing at no more than 150hz maximum (probably more like 100hz).
I've spent the required many hours of googling around subwoofer design and FAST setups but am concerned that I don't fully understand the principles of the kind of drivers I should be looking at. Its not earth shattering home cinema sub action I want, these are for music, and just need to add some support to those lower frequencies.
I hooked some rubbish drivers just to give it a go and am convinced a sub-type support will help.
I've toyed with building a small box with a couple of Peerless 6.5 inch woofers in (a dual setup appeals because i could eventually repurpose for a totally different speaker build in future), but then wonder if a single 8" or 10" would be better, or more suited to the job. Can anyone offer any tips on the driver parameters or 'type' I should be focussed on? Should I even allow myself to be drawn into spending loads on drivers for this narrow job and just focus on getting something half decent and unobtrusive (Europe Audio sells some pretty cheap Monacor's that look good)? Or these Peerless 830657 or 830667. Ideally I don't want to be spending more than £50-60 on drivers.
HELP!?!?
OK, so my 10.3's are finished. As are the Ikea salad bowl project with the tiny Alpairs, that sound simply amazing.
When I was last stateside I bought a subwoofer plate amp for the little Alpair 6's in salad bowls. However for nearfield listening they don't need any more support - amazingly!
However, I am missing some extra bottom end for the 10.3's. WAF has fundamentally ruled out Pensil enclosures, so I am now looking into the possibility of adding a sub with plate amp, crossing at no more than 150hz maximum (probably more like 100hz).
I've spent the required many hours of googling around subwoofer design and FAST setups but am concerned that I don't fully understand the principles of the kind of drivers I should be looking at. Its not earth shattering home cinema sub action I want, these are for music, and just need to add some support to those lower frequencies.
I hooked some rubbish drivers just to give it a go and am convinced a sub-type support will help.
I've toyed with building a small box with a couple of Peerless 6.5 inch woofers in (a dual setup appeals because i could eventually repurpose for a totally different speaker build in future), but then wonder if a single 8" or 10" would be better, or more suited to the job. Can anyone offer any tips on the driver parameters or 'type' I should be focussed on? Should I even allow myself to be drawn into spending loads on drivers for this narrow job and just focus on getting something half decent and unobtrusive (Europe Audio sells some pretty cheap Monacor's that look good)? Or these Peerless 830657 or 830667. Ideally I don't want to be spending more than £50-60 on drivers.
HELP!?!?
You want drivers with reasonable extention on the top (smooth response is nice too), and that will go as low as you need in a box you can fit in. There are a wealth of choices, look for something easily to hand.
As to 1 woofer, or a pair, i very much prefer pairs of smaller drivers, especially if i can mount them push-push.
dave
I have some 6.5" Peerless woofers on order and have been modelling boxes tonight on WinISD. I've done plenty of research into the effects of push-push on enclosure volume calculations. WinISD says I need 95l for dual drivers in standard configuration. Do I simply halve that if I mount the 2 drivers back to back (push-push)? Essentially modelling the box size for a single driver and then put 2 drivers joined back to back, and wire in-phase. Is that right?
I'm sure I read somewhere that you halve the Vas for each driver in winisd when dual-driving but can't find it again. I guess that all adds up to the same thing!
I'm sure I read somewhere that you halve the Vas for each driver in winisd when dual-driving but can't find it again. I guess that all adds up to the same thing!
I have taken you advice, done various modelling and have what I think to be a pretty good solution. My idea is to put the 10.3's in a sealed enclosure of around 5.5l, integrated into a floorstanding ported box with the woofers sidemounted. See illustration below. I'll be crossing around 150hz, which is exactly the point WinISD shows the Alpairs dropping off.
I'll still be powering the subs with a plate amp, which goes to 200hz so I think it'll all be good. Anyone see any glaring problems or improvements? I know I could start introducing 'low pass filters' but then I'm moving further away from the fullrange model and essentially just building some 2-way floorstanders.
How am I looking?
I'll still be powering the subs with a plate amp, which goes to 200hz so I think it'll all be good. Anyone see any glaring problems or improvements? I know I could start introducing 'low pass filters' but then I'm moving further away from the fullrange model and essentially just building some 2-way floorstanders.
How am I looking?
Attachments
Woofer looks a bit far away from the FR unit - probably having them closer would be better.
Dave and others more experienced would be able to comment on sealed box size - what I have read is that sometimes "flat" alignments from WinISD or similar box design software might sound boomy in the midbass region in rooms...
Your slant looks too much also - probably a gentler slant will suit you better.
Yes. woofer & FR should be less than a 1/4 wavelength apart at the XO point (150 Hz = 22.6")
dave
And FWIW, while I realize they may model quite nicely, and even sound fine enough in a sealed enclosure, it would appear that you have more than enough total enclosure volume to consider a tapered TL for the Alpair. We've had great success with that approach in several builds - one with A7.3, and two separate designs with a different make.
Aagh, the t-line consideration. I have spent a long time looking at TL's for sure, even very nearly buying a 2-way kit from IPL Acoustics in the UK. I just don't trust my ability to build a cabinet with the right dimensions and tube length etc. I also can't quite believe that a TL would deliver the same level of frequency response. The enclosure model I posted above is around 1100mm in height, 200mm wide and about 270 deep (externals). I don't really want to go beyond that, and it gives me an F3 of 39hz according to WinISD. If there is TL for the full ranger that will give me equivalent response I'll definitely consider it - but I don't have the skills to model it.
The enclosure can be monolithic, with 2 chambers:
- One chamber for the woofer - can be ported or sealed according to design, choice of woofers
- On top of the woofer chamber, a smaller tapered TL chamber for the Alpair. This chamber will have a port exiting from its rear into free air - in no way should it be connected to the chamber for the woofer (the air volume should not be shared)
- One chamber for the woofer - can be ported or sealed according to design, choice of woofers
- On top of the woofer chamber, a smaller tapered TL chamber for the Alpair. This chamber will have a port exiting from its rear into free air - in no way should it be connected to the chamber for the woofer (the air volume should not be shared)
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http://www.diyaudio.com/forums/full-range/144099-thread-tysen-variations-fast.html
Some drawings in posts 5 & 6
dave
Yes, although already confirmed- what Zia said -what I was trying to suggest was a separate tapered and highly damped (near aperiodic) TL , rather than sealed compartment for the Alpair. As it would be higher band pass than if for the full range of which the driver is actually quite capable, it could well be not much different in volume consumed within the total enclosure.
Just a personal preference, based on having built and listened extensively to at least 3 designs of such format - but with no objective scientific data or modelling to support.
Just a personal preference, based on having built and listened extensively to at least 3 designs of such format - but with no objective scientific data or modelling to support.
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