funkydoug

It works as an 'event' - like the long jump. You've set a record of 7hrs until we get a longer one!

Some serious staying power! Nice to see some extreme endurance champions to counterbalance this morning's sprint

Hi folks, A bit of pure basschat geekery here. Look away if you're expecting anything useful or even musical... Think @warwickhunt and I may have set a record for the fastest sale. From me posting the advert to the item arriving in his hand it took 32 mins according to the forum clock. It was a totally genuine sale with no prior contact or other shenanigans. I confess to getting a kick out of it ...and was relieved that there were no speed cameras on the way 🤣 Happy to take a drug test if the moderators insist 🤣... can anyone beat our time, or claim another Olympian feat?

Hi Phil, just a quick one to say thanks for the message above. I'm still in the planning rather than doing phase - this thread has been extremely helpful.

Hi Phil - any chance you could enlighten me on how you achieved this flat response down to about 55-60hz? And are these charts taking Xmax limitation into account? Thanks again, Doug.

That's my conclusion too. The power and eq flexibility in the amps mean that we don't notice until we open them up!

AFAIK it is the original driver and the piezo was also factory fitted. I studied the few photos of them online and came to the conclusion that despite Ashdown's blurb, this one never had a port or a posh tweeter. I also noted the deliberately ambiguous product description you spotted Stevie. Not the first time I've come across Ashdown being inaccurate when it comes to providing details of different amps / cabs across a given range. I'll let them off, the amps are great. Ok, I've got a few really good options here for adding a port which I'll think more about. I'm leaning towards a large rear facing port, as it'd avoid cutting more out of the baffle to the point where it starts to lose stiffness. Once I've got the design right I'll just need to avoid making a mess of the tolex. The piezo has a 77mm cutout. I'd need to find a same size upgrade I reckon, as expanding that cutout would be difficult (for me!). Off to re-read the easy build 10 thread ...

If the drivers are identical in the both cabs, do they also need to tuned identically?

This is looking like a great idea. Will very closely re-read the thread. Thanks

Morning all, Really appreciate your engagement and the time you've given. I measured the cab and the internal volume of the box is 42.3 litres. I'll need to deduct the driver itself from that but there are no handles or braces (unfortunately!) to deduct. I'll revisit the modelling given what's been said. Is there an alternative to WinISD that is less 'buggy'? One other consideration I have is that the cab/combo needs to be able to play nicely with an extension cab. The extension cab will be a vented 210. Do I need to tune this box the same as that one to avoid wierdness?? Maybe that's one reason to keep it sealed, so that it doesn't mess with what's happening with a vented extension? I'm open to all options, all speaker upgrades and even keeping it sealed and for now will keep experimenting in the modelling realm when I can. As I said in the OP, this is as much about learning as it is about the result, so although some might think I'm over thinking it, that's kind of the point! I clearly don't understand this stuff very well yet, but that's why I'm asking. That said, it's a busy family bank holiday weekend with young kids, so there's not a lot of scope for geekery today!

Totally unlined. Yep I'll add some. Did that to one of my other Ashdowns lately, easy job and quite satisfying. That one sounds great now. I put a new crossover in it and lined it, having learned a lot from you and a few others here. This one remains in factory condition and while the amp is great and the combo is ideal in lots of ways there are a few modifications in mind: lining it, maybe bracing it and working out what to do about the low end, hence this thread. I'll measure properly this weekend and report back. 👍

Thanks Stevie, I'm not with it just now to measure up, but I took this shot of the baffle when I was inspecting the driver. Think a 4inch port might just fit . Will measure it when I can. Very much appreciate the input guys. Also, you'll spot that while the other cabs and combos in this NEO range have APT80 tweeters the baby of the bunch got what looks like a pretty basic piezo. No complaints on how the tweeter sounds though.

Might put an Eminence SC10-16 in there. On the face of it, it looks like a downgrade but it seems like a better fit for the box and amp. Would see no more than 100w from the amp at 16ohms, and is designed for sealed cabs. Won't sound massive but might sound right for a nice small 10. Hmmm...

Yeah I've really enjoyed those threads, and was impressed by your combo version too! I don't have tools or any space for a project like that (yet!) so I'm thinking that modding and / or modelling might be a good way to start tinkering. This one is actually a nice and quite rare little combo so I'm not going to hack into it unless I am sure it's a good idea. I've done that before ... some here might remember... and although it worked out ok in the end, it was pure luck!

Its an Ashdown combo, like this: https://ashdownmusic.com/products/abm-c110h-400 Very nice little amp, and very handsome too, so I'm not in a hurry to mess with it, just exploring options as to how to get the most out of it. I think I've underestimated the volume ... It must be more like 55-60litres but I can't measure it just now. Apologies to those who've already contributed based on it being 40L! Edit: I've added this later in the thread, but to avoid confusion here, the volume of the cab is 42 litres minus the driver itself

Thanks Phil. Yeah, I am almost enjoying the experience of finding myself wrestling with the trade-offs. Its a good learning process for sure. HPF is definitely part of the solution for the cab, whether sealed or vented as excursion is a problem either way. One thing I noticed was that the driver has QTS of 0.33, pretty low for a sealed cab?? Might explain why there is so little bottom end. Maybe replacing the driver would be a better idea. This is the driver:

Thanks for you input Bill. I'll check when I'm back home. It has Xmax of 4mm, so its not too bad in that department.

Thanks @agedhorse, kind of reassuring to know that "it's not me, it's the box"! If I go up to 10cm diameter it needs to be about 20cm long to maintain the tuning, and this brings the port speed down quite a bit. That is longer than I 'imagined' it being, but you're (of course) right that it would do a lot to reduce the problem. The cab is about 30cm deep, so assuming I can find a 10x20 port - or make one - and that it fits the baffle, this should work. On the other hand ... maybe this is why they made it a sealed cab! Much appreciated.

Any input much appreciated on this one folks... I am toying with the idea of adding a port to a sealed cab, mainly to get some more bottom-end but also as a bit of a learning project. I am modelling it in WinISD and can't seem to arrive at a port config that works. Can anyone help? Box size: 41 Litres Driver: 1 x 10inch SICA (I know, never going to sound huge... but it is what I have got to work with on this project). The puzzle: I set the port diameter at something sensible like 7.5cm which seems okay in that it will fit on the baffle, is about the diameter of a lot of other ports, and I can buy a ready made port of this diameter from Blue Aran. Doesn't strike me as an unusual choice. This all looks ok, WinISD tells me it should be a reasonable length to achieve the tuning I am modelling (for 45hz the 7.5cm port should be cut to 10.4cm). All good. The issue comes when I look at the air velocity charts for the port. It says air velocity down at the tuning frequency will be over 100ft per second with a 100w signal. That speed is more than twice what google tells me I should aim for. My questions: Am I missing or mis-understanding something? Probably. Is it a non issue because there is rarely much power in those low frequencies? What is normally done to resolve what looks to be a basic tension between the competing priorities of wanting a port of about this size (most cab designs don't permit enormous ports), of practical length (can't have one longer than the depth of the cab!) and with air velocity that doesn't get into 'chuffing' territory? For now I'll keep reading and modelling and trying to work it out. I am not going to reach for the hole-cutter and ask questions afterwards - as I have been known to do in previous 'projects'!. Thanks in advance, Doug.

Mike recently bought an amp from me. 'Twas a smooth and easy transaction. You can be 100% confident in dealing with him.