Sharkfinger

My amp is an EA iAmp800, which produces 500W at 8Ohms, so well matched with speaker. Got an old-fashioned toroidal transformer in it, so not short of power. Got my eye on an old bass cab on eBay with considerably more internal volume, circa 110 litres. Think that will make a difference? Modelling it at 46Hz seems good, although with a big 'maximum power' dip.

A nod of 'hello' from another Herts based BCer.

I extended the shelf of the TL606 box by the amount specified by WinISD and as if my magic, it now almost sounds like the Ashdown. Gigged it this weekend and indeed it does have a tiny bit more bottom end and volume. I still plugged in my extension cab, though, as that gig just needed more 'oomph' as we didn't have the full PA that night. There really is nothing like a 2x15 to my mind. Is there no cure for a bigger box and more speakers? I might experiment with making with a compact 2x15 cab.... and maybe make it into a combo.

Great advice, I'll do that. I meant to buy some of that foam strip, so I'll try that. BTW, did you download the driver file from the same place I did or did you put the values in yourself? In which case, any chance you could share your file?

Didn't hold up much hope of a great benefit with this TL 606 box, so I didn't invest a great deal of time thankfully. doubt the ashdown leaks, as it's vinyl covered but I can check the ports. I'll give extending the Ashdown ports a try, as I love the way that sounds. Not sure how I'm going to do that, though. As for the wadding, do you mean at the base of the port (on the inside)?

Perfect sense, thanks. I'll let you know how I get on.

If you don't find anyone to pick them up and were willing to post, i'll take the bass bits.

Interestingly, making the porting the same as the ashdown, then changing back to the long slot makes no difference to the 'transfer function' or 'maximum power', as long as the tuning frequency stays te same. So looks like there's no point in changing the port type. That's saved me a lot of work (which I wasn't going to put in anyway).

Manage to understand couple of things out of that. Using the full width of the opening (45cm) and the actual height of 5cm, along with an 'acceptable' tuning frequency of 46Hz, gives me a vent length of 25cm, from which I'll subtract the depth of the baffle. I'll see where I go from there. Don't have a gig for a couple of weeks so have a while to do it. Don't have the original model for the ashdown, as Stevie did it for me. Don't know for sure what it's tuned to. But I do notice that to get the port length to 15cm, as advised, the tuning needs to be 56Hz, so that must be what it's tuned to. Interestingly, with all the same porting, etc the TL606 has more 'bottom' but the ashdown has a smaller 'dip' in the maximum power.

Interestingly, if I just have a 'centre' vent and block the side ones, I can have much shorter vent length and tune it lower, it would seem.

Interesting! Well, think I'll settle on 50Hz, as that's a vent length of 28.4cm. Should I subtract the depth of front panel, the 18mm ply? Should I also subtract the width of the supports? 2x18mm.

That tuning frequency was pre-populated. Did try messing about with it but as I didn't really know what I was doing, I reset it. I'll make sure I've got the 'slot' dimensions right, then play with the tuning frequency until I get to a 'vent length' that looks reasonable. Edit: Hmm, not sure about that: with a vent length of 27cm , it will be tuned to about 51Hz. Seems a little high to me.

That's a good suggestion: might block off shelf at the front and use the two end parts as square ports. The opening height i stated might have been a bit ambitious, it's probably only about 6-7 cm high. Width of each end section is probably only about 12cm, so I've modeled that to much better results. Best thing is, it's not a lot of work to find out if it's viable. Invested a fair amount of work into the Ashdown combo, so only want to trial this to see if it's worth 'tarting it up' to look better. I would also turn it into a combo by sticking a box on top for my amp but won't do any of that until I know it's worth the investment in time. A bit of high-powered image editing..... That what it would look like from the inside. I know: you would never know I used graphical editor.....

I did think of that, which is why I changed the port to be square and then tweaked the dimensions to make it rectangular (last WinISD image). However, it came up with a 'vent length' of 44.54cm, which is longer than the cab is deep. Could make it shorter of course, but by how much?

Need some help with WinISD. Having had such marvelous tonal results with upgrading an Ashdown combo, I wondered what would happen if I put that BMS 15N620 speaker into a slightly bigger (deeper at the back) box. As good as it sounds, I'm finding I usually have to take my 1x15 extension cab to comfortably get enough volume and bottom end. On its own, the combo has nearly enough of both, but not quite. My intention is to have the same tone as the combo but have that little bit more output and bottom end, that would allow me to leave the extension cab at home for the majority of gigs, which are usually small to medium sized venues. I've got a TL606 box lying around (pictured below) and just for sh*tz and giggles, just put the driver in and used it at a gig. There is a bit more bottom end and volume but that seems to be at the expense of the 'crisp' top end. I've now downloaded and installed WinISD and found a driver file for the speaker here. Starting a new project with this driver (which says the 'driver data fails integrity check' but lets me carry on), I choose 1 driver with 'normal' placement, 'vented' design and an alignment of 'QB3 Quasi-butterworth', which seems to be default. I tweak the box volume down a bit to reflect the internal size of this cab (about 86 liters) and leave the tuning frequency at the recommended 46.24Hz. Now, it seems to want offer me a single round vent of 10cm with length of 5.27 cm. Now, this cab just has a 'slot' opening at the bottom, which is just an opening, no 'vent' as such, which is probably why it doesn't sound great. I can change the shape to be square and tweak the setting to be the same width and height as the opening at the bottom but it suggest a length that is longer than the cab is deep. No problem, can just seal that easily enough and re-port it. Does the round vent above sound about right to you guys?

Think it's gone a fair bit past 'muted' and my left ear is still fine. Now I think about it, I first really noticed it when I first got my IEMs. With my finger, I covered the ambient port of my left ear-piece and the it muted the top-end. Did the same with the right and it made bog-all difference. Though the port was blocked, before I realized what the problem actually was. Without realizing it, I'd also started holding my phone against my left ear some time ago. When I switch it back to my right, I definitely can't hear it as well.

Read the first couple of pages before it became childish and then just skimmed the rest. I've protected my hearing for the last 20 years or so, mostly with vented plugs, mostly molded but off-the-shelf stuff as well. In the last 5 years or so, I've used custom molded IEMs with ambient ports, which I suppose can be counted as vents. However, in the last 10 years or so, I've noticed that I can no longer hear the very 'top end' frequencies in my right ear with a tiny amount of tinnitus. I attribute this to the fact I usually stand with the drums on my right, with one of the cymbals right next to my lug 'ole. And snare not far behind that. My inner ear has changed (as they do over the years) and I was at the point where I needed them adjusted/re-molded but struggled to justify that kind of expense again. I bought a second had pair of 3-driver isolating IEMs of eBay and the sound is great. Having read this though, it would seem that I should go back to the ported custom molds. Don't think my hearing's got worse in the last few years of using them but can't be sure.

From what I understand, the Quilter BB800 uses a proprietary power module, not the ICEpower module as merton pointed out.