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New BassChat 8"Cab design


Phil Starr

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1 hour ago, Phil Starr said:

Would it help if you made this your main practice speaker and could store everything else out of sight? 

 

If even this is too big there is a smaller alternative https://www.basschat.co.uk/topic/455858-house-jam-micro-cab/ 

I've looked at the 6" cab, in the house i use headphones for practicing, my amp/cab setup is either a markbass F1 or an orange terror bass, running through either 1 or 2 Barefaced midgets (Gen 2) so not exactly big. All my kit is stashed away out of sight in my little study as it is (which has floor to ceiling shelving on every available wall) and any  cupboards are already full of my other kit (recording stuff, Guitar amps, Mic's and about half of the shared PA for my band) the 8" cab would work well for acoustic practices at the guitarists house using the F1 (or maybe one of the tiny 200W heads like an elf) and for monitoring or small venues with my EUB or my U-Bass.

 

looking at the dimensions the 8" cab isn't that much bigger than the 6 so if i can find somewhere to squeeze it in then i'll have a go at building it.

 

Matt

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53 minutes ago, Matt P said:

I've looked at the 6" cab, in the house i use headphones for practicing, my amp/cab setup is either a markbass F1 or an orange terror bass, running through either 1 or 2 Barefaced midgets (Gen 2) so not exactly big. All my kit is stashed away out of sight in my little study as it is (which has floor to ceiling shelving on every available wall) and any  cupboards are already full of my other kit (recording stuff, Guitar amps, Mic's and about half of the shared PA for my band) the 8" cab would work well for acoustic practices at the guitarists house using the F1 (or maybe one of the tiny 200W heads like an elf) and for monitoring or small venues with my EUB or my U-Bass.

 

looking at the dimensions the 8" cab isn't that much bigger than the 6 so if i can find somewhere to squeeze it in then i'll have a go at building it.

 

Matt

Or something like this

 

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I've been doing a bit more planning for people who want to build this. The original as I've said was built to match the form of an Ashdown combo. There's no need to do that and by tweaking the shape a little I can get the panels cut out of a 1220x610 sheet of ply, the sort that are sold by the big sheds. B&Q in particular offer a cutting service at most of their stores. I can pretty much keep the same shape if I change to 12mm ply, a cute cube :) that will save a few pounds and a few grammes but the cab may need stiffening with some braces making it a slightly harder build. If I stick with 18mm ply I don't think it will need bracing and 18mm is what we've tried. It will however have to be 54mm taller. My instinct is to go for 18mm in the recommended design and let those who want to save weight work out the bracing for themselves. I think this should be the simplest design possible but with plenty of notes so you can modify if you wish.

 

The good news is that the 18mm ply is £19.97, the batten is £7.37 the speaker £44.22 and the connector £12.50 if you go for the most expensive ready wired version so that is £84.06 for a basic box plus speaker. B&Q will make 5 cuts for free. I've found that if you are nice they don't really count the cuts if they are simple.

 

Does anyone have strong feelings about 18mm v's 12 mm ply

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in such a small cab Phil, I would doubt that the 18mm ply would cause any carrying issues....

 

If it results in a simpler build, then i guess more people would be inclined to have a go (hopefully)

 

I, for one cant wait to see whats produced in sheds up and down the country! :)

 

 

 

 

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24 minutes ago, Phil Starr said:

 

Does anyone have strong feelings about 18mm v's 12 mm ply

A single brace connecting the middles of two 12mm panels gives the same vibration resistance as using no brace with 24mm panels. That's why I don't use 18mm in any of my designs, while some use only 3mm and 6mm, with no vibration issues.

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11 hours ago, Jackroadkill said:

 

Could this be done with a rectangular box with an internal baffle and two ports of the original size?

 

11 hours ago, Phil Starr said:

No

 

One of us is misunderstanding the question.

 

Pretty sure the original has one port and it's a cube. Two ports and an internal baffle would be needing two drivers and would do well to be rectangular to the front.

 

So I figure he was asking about doing a 2x8?

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8 minutes ago, Downunderwonder said:

So I figure he was asking about doing a 2x8?

Yes, that's what I meant.  Effectively two speakers, each in their own enclosure, a baffle between them and a port in each enclosure, only the wiring being common.  Sorry for the brevity of my question above - I posted it on the sly whilst in work.

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2 hours ago, Phil Starr said:

Does anyone have strong feelings about 18mm v's 12 mm ply

 

You've probably gathered I'd prefer 12mm but I should be able to work things out for myself. And I've got some 68mm plastic pipe so I'm halfway there already.

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3 hours ago, Jackroadkill said:

Yes, that's what I meant.  Effectively two speakers, each in their own enclosure, a baffle between them and a port in each enclosure, only the wiring being common.  Sorry for the brevity of my question above - I posted it on the sly whilst in work.

A brace is all that is required between drivers.

 

Sealed cabs do separate enclosures so that one driver going bad can't take out the rest from losing all the back pressure.

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7 hours ago, Jackroadkill said:

Yes, that's what I meant.  Effectively two speakers, each in their own enclosure, a baffle between them and a port in each enclosure, only the wiring being common.  Sorry for the brevity of my question above - I posted it on the sly whilst in work.

Sorry about the brevity of my answer. I was in the middle of re-jigging the cabinet shape to fit on a smaller sheet of ply to make a cheaper build and as @Downunderwonder said missed the bit about the baffle in between.

 

So, yet that would work but probably isn't the best way to do it. Miss out the baffle and just double the volume and calculate a new port is better. A lot of this design is about the practical problems of packing everything in to a small cab. I'd prefer a bigger port but easily available plastic pipe of the right diameter isn't available. Creating a wooden port would make the build more complex and put people off, I wanted this to be the simplest build possible. If you double up you can use a bigger port and you have to re-tune anyway. If you decide a 2x8 is what you want then you could fit a 110mm soil pipe as a port. 11cm will give the same tuning. the bigger pipe will reduce the chance of turbulence and port chuffing to just about zero.

 

That would give you a 4 ohm, 450W cab capable of 122db continuously capable of matching up with any drummer. You could probably keep the weight down to around 11kg depending upon whatever material you decided to build in. It would be a serious cab :)

 

 

 

 

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7 hours ago, tauzero said:

 

You've probably gathered I'd prefer 12mm but I should be able to work things out for myself. And I've got some 68mm plastic pipe so I'm halfway there already.

I like this a lot. People should feel free to adapt to their own needs. If you have any problems/questions then if anyone wants to ask here I'll do my best to help.

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2 hours ago, Smanth said:

@Phil Starr ... this looks amazing!

Small, light, enough oomph for my needs and possibly powerable from a battery amp ... I love it!

It's about time I use my makerspace membership to do some woodwork! lol

S'manth x

Hi Smanth, can we expect to see this at the next bass bash :)

 

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the lighter the better for me so i'd go for 12mm ply. I don't mind adding in some internal struts or braces to make it work better.

 

Matt 

 

EDIT - I've just re-read @Bill Fitzmaurice post above about braced 12mm behaving like 24mm, does this scale? could simply braced 9mm ply be used for an ultra lightweight cab? 

Edited by Matt P
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1 hour ago, Matt P said:

the lighter the better for me so i'd go for 12mm ply. I don't mind adding in some internal struts or braces to make it work better.

 

Matt 

 

EDIT - I've just re-read @Bill Fitzmaurice post above about braced 12mm behaving like 24mm, does this scale? could simply braced 9mm ply be used for an ultra lightweight cab? 

I believe Barefaced use 9mm ply on some cabs but the bracing they use is very complicated. You can also. Reduce the weight by changing the species of timber used in the plywood construction.

 

In the Basschat Mk3 12” cab, the prototype* was built using 18mm spruce but the final cab used 15mm Italian Poplar. You also need to look at the number of plies. One Italian poplar we found had 7 while another had 9 for the 15mm sheet.  More plies give a more rigid panel. Of course the lighter the panel, the softer the wood so there is a trade off between the rigidity and strength of Birch down to the lightness of Spruce or Poplar. Oh course the ideal cabinet material is concrete with MDF being a close second. However I would not recommend either Thor a transportable cabinet.

 

If you can cut the sheets yourself, some builders merchants have poplar ply faced with hardwood ply on the outside. I know @Phil Starrhas seen it at Jewson but they do not sell the small panels and do not usually do a cut to size service. It is also of Chinese origin so weather rather quality stacks up against Italian Poplar I do not know. 

 

*actually the prototype was for the Mk2 version

Edited by Chienmortbb
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1 hour ago, Matt P said:

the lighter the better for me so i'd go for 12mm ply. I don't mind adding in some internal struts or braces to make it work better.

 

Matt 

 

EDIT - I've just re-read @Bill Fitzmaurice post above about braced 12mm behaving like 24mm, does this scale? could simply braced 9mm ply be used for an ultra lightweight cab? 

I think the answer is yes, but. Going to 9mm will require a lot more thought and bracing than 12. If you do build a cab, the best thing to do it feel around the box while playing various bits of mosaic through it. You will soon find the resonant points and hence where to brace.

 

Thinner panels may not be suitable for baffles. The driver cutout plus the extra weight of the driver means is more stressed than the other 5 panels.

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1 hour ago, Matt P said:

the lighter the better for me so i'd go for 12mm ply. I don't mind adding in some internal struts or braces to make it work better.

 

Matt 

 

EDIT - I've just re-read @Bill Fitzmaurice post above about braced 12mm behaving like 24mm, does this scale? could simply braced 9mm ply be used for an ultra lightweight cab? 

That's one way of looking at it, I don't want to get into a long debate about bracing but my belief is that it is much more complex than even a good rule of thumb would suggest. It would become a bit of a thread de-rail. 

 

There's a difference between opinion and experience. I've built and tried all the cabs I've designed and recommended on BC. I built the prototype for this out of 18mm and panel resonance is not a problem. I doubt that there would be a problem with 12mm ply but I haven't tried that yet. Thinner panels are lighter and bend more easily but these are still small panels, they are also braced all around the edges so I don't think that would be a problem, I've been designing and building cabs for 50 years so that is a bit more than a guess but the proof is 'in the eating'. I'm most concerned about the baffle (front panel) as with two cut-outs the panel is weakened there is no central point to fix to as the speaker is in the way. An 18mm baffle and 12mm might be better for a manufacturer but adds problems in sourcing panels for most people who might build this.

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Can I ask if we can keep this thread for people who are thinking of building this exact cab or a direct variation of it. I know these threads get used many years after the initial post and there is a lot of patience involved in sorting out essential details when you get to 20+ pages.

 

Many thanks :)

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OK we are going for 12mm, the lightweights have it. I'll put up the dimensions for the 18mm panels too so you can build the one you prefer. We should have full plans next week and a cutting list to go with it.

 

I'm going to rake through some of my old pics and put up a 'How To' guide, it won't be for this cab as you'll have to wait too long but it will show all the steps.

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I used a pair of those Fane Sovereign 8-225 drivers to modify my TC BG250-208 combo to internal 4 ohm load. I've used this as my backline/monitoring on a number of acoustic gigs and this set up loves my NS EUB too.  

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2 hours ago, chyc said:

Can I just check this is the Fane Sovereign 8-225 driver? There is a Fane Sovereign Pro 8-225 and I have no idea what the practical difference is other than the difference to my wallet and the stock levels of them at Blue Aran.

In general, the Pro versions of the Fane Sovereigns are on cast Aluminium chassis rather than the pressed steel of the non-Pro versions. The cast aluminium chassis are preferred in larger diameter drivers but for an 8". IMHO, there is no benefit. In fact, the cast aluminiom Pro chassis increases the weight somewhat.

 

So in conclusion, get the non-pro version. Fane Sovereign 8-225

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Whilst waiting for Phil's design to appear, I had a bit of a virtual chinwag with him and he was kind enough to share some info on the new 8" cab we're all chatting about. 

 

I'm an impatient beggar, so i've gone off piste and drawn my own on CAD. 

 

I had the 12mm ply panels to make a third BC110T in my shed, so I ripped them down with a saw and sled last night and got busy. 

 

I've air nailed and glued a side and the back to the base and marked up the holes for cutting out this evening. 

 

I've then got to make up my bracing parts and fit them before fitting the baffle, other side and top. 

 

I've also gone a bit rogue with the porting. I've opted to go a bit bigger, but still tune to phils intentions. 

 

THIS IS NOT PHILS DESIGN - His (undoubtedly better) design will be along soon. 

 

Mrs Glambass kindly delivered me a cup of tea last night and exclaimed "It's tiny!" - not the first time i've heard her say that.....

 

Looking forward to seeing how it turns out visually and sonically

 

Cheers! 

 

8888.jpg

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