1x12" Cab Design Diary

[Chienmortbb]

Just out of interest. Was the 19mm Ply birch? I have some 19mm spruce ply (slightly softer but lighter then birch) in the garage and was wondering if that would sound much different.

[Phil Starr]

The ply was sold as 'baltic birch' it was pretty poor quality tbh with patches in the faces and it splintered badly under the saw. My opinion is that one of the qualities that makes a good panel is high mass, so there is a compromise between the 'deadness' of the cab and being able to lift it. My Hifi cabs always use MDF for example but my preference is for 3/4 ply as a good compromise for stage gear.

Building both a braced 12mm and an unbraced 18mm cab in this process was to check it wasn't ignorant prejudice on my part. I much prefer the sound of the 18mm version and the panels certainly vibrate less with high power sound. It may be that i could rearrange the bracing for better effect and I intend experimenting more but I was aiming for an easy build which didn't need sophisticated machine tools so I didn't do too much this time.

[Woodinblack]

There was quite a lot of background noise in the recordings, and the first set of recordings weren't flat.

Here are two short recordings of the two cabs, playing the same phrase with both on the same amp (markbass set eq flat), played next to each other. There is more but it is very noisy.

However, the conditions are very similar (and distances the same) as the test on the somerset bash, so these could easily be compared with the markbass recordings.

Anyway:

A: [attachment=203220:SpkrA.wav]

B: [attachment=203221:SpkrB.wav]

[JTUK]

I prefer A, but that has to be taken in terms of the sound and parameters of the test.

[Phil Starr]

[quote name='Woodinblack' timestamp='1445454474' post='2891665']
There was quite a lot of background noise in the recordings, and the first set of recordings weren't flat.

Here are two short recordings of the two cabs, playing the same phrase with both on the same amp (markbass set eq flat), played next to each other. There is more but it is very noisy.

However, the conditions are very similar (and distances the same) as the test on the somerset bash, so these could easily be compared with the markbass recordings.

Anyway:

A: [attachment=203220:SpkrA.wav]

B: [attachment=203221:SpkrB.wav]
[/quote]

Ok the two recordings are of two cabs both fitted with the Beymas One has a 12mm wall, tubular ports and is extensively braced and the other has an 18mm wall, slot port and no bracing. Both are 50litre cabs tuned to 50Hz.

I don't know which cab is which and embarrassingly I can't be sure from the recordings which is which either. I have gigged the 12mm cab extensively but only had 10mins with the 18mm cab before giving it over to Stevie. I wasn't there when the recordings were made at the Southwest bass bash. The differences aren't huge but I do have a preference. I'm not saying though until I hear what you think.

If you can't open the recordings I found Windows Media Player opened them but I'm told you can copy them onto your desktop and rename them as wav files as an alternative.

Though weirdly Basschat has done this for you when I used Woodinblacks post as a quote

Edited October 21, 2015 by Phil Starr

[Phil Starr]

Another sound clip for you. This is me, so forgive the playing, it was our first run through of this particular song so there is some hesitancy but you can hear the tone quite well. It has what I think of as a slight 'thoatiness'. This is using my Hartke HA3500 and I think I had my Fender Highway One Jazz for this. Can't remember all the eq but the deep bass is rolled off at 30hz on the graphic cos i always do that.

https://soundcloud.com/philstarr-1/black-velvet-27-april/s-wnPYC

[Beer of the Bass]

I like B better out of those recordings, though the difference doesn't seem huge. Both are a more pleasing tone (to my tastes at least) than the recordings of the Markbass combos from the same day.

[cheddatom]

They both sound good, one of them has more pronounced high mids but that can always be EQ'd

[Phil Starr]

[quote name='Beer of the Bass' timestamp='1445509347' post='2891956']
I like B better out of those recordings, though the difference doesn't seem huge. Both are a more pleasing tone (to my tastes at least) than the recordings of the Markbass combos from the same day.
[/quote]
You've no idea how encouraging that is. I know these speakers model well and that they are hugely capable of handling bass and high volumes well but the voicing is something else. I'd feel really responsible if no-one else liked them. That's the first ever comment to directly compare them with a commercial cab.

Edited October 22, 2015 by Phil Starr

[Guest bassman7755]

[quote name='JTUK' timestamp='1445458724' post='2891707']
I prefer A, but that has to be taken in terms of the sound and parameters of the test.
[/quote]

Me too, B has some slight extra unpleasant colouration as far as I can tell.

[Chienmortbb]

I preferred A in the first two sample. In the rehearsal, I can forgive your hesitation. Black Velvet is a deceptive song in that if is all about the bass and the passages ate the end of the chorus are a B. I read that the bass line on the record was a mixture of real bass and synthesised bass. Or maybe that was my excuse as I found it hard,

On second and subsequent listenings the B speaker seems mid heavy or bass light. I am using AKG 450 headphones from an old macbook pro so the quality should be OK.

Edited October 23, 2015 by Chienmortbb

[Phil Starr]

[quote name='Chienmortbb' timestamp='1445601082' post='2892719']
I preferred A in the first two sample. In the rehearsal, I can forgive your hesitation. Black Velvet is a deceptive song in that if is all about the bass and the passages ate the end of the chorus are a B. I read that the bass line on the record was a mixture of real bass and synthesised bass. Or maybe that was my excuse as I found it hard,

On second and subsequent listenings the B speaker seems mid heavy or bass light. I am using AKG 450 headphones from an old macbook pro so the quality should be OK.
[/quote]

you were supposed to be judging the tone of the speaker, not my bass playing

And you are right about the end of the chorus, fixed now.

[tauzero]

I prefer A from that small sample but I'd want to spend a bit more time with them and try them with songs I do.

How heavy did each of them finish up?

[pete.young]

[quote name='Phil Starr' timestamp='1445330839' post='2890544']
My Hifi cabs always use MDF for example but my preference is for 3/4 ply as a good compromise for stage gear.

[/quote]
That's triggered an odd memory - I'm sure I read somewhere about some cabs that used MDF for the front panel and ply for everything else, but I'm damned if I can remember where I read it.

[Phil Starr]

[quote name='tauzero' timestamp='1445678023' post='2893266']
I prefer A from that small sample but I'd want to spend a bit more time with them and try them with songs I do.

How heavy did each of them finish up?
[/quote]

the 12mm was 14.kg ish and the 18mm cab was about 1.5kg more. If I'd made the ports with plastic pipes in both cabs I think the difference migh have been down to nearer a kg. I haven't actually had time to weigh the finished 18mm cab before I sent it off to Stevie

[Phil Starr]

[quote name='pete.young' timestamp='1445687565' post='2893410']
That's triggered an odd memory - I'm sure I read somewhere about some cabs that used MDF for the front panel and ply for everything else, but I'm damned if I can remember where I read it.
[/quote]

It was common at one point for cabs to have a ply skin (top,bottom, sides) because it was tougher but mdf or high compression chipboard for the baffle and rear panel to save money and get less resonance.

[Chienmortbb]

Glad you got Black Velvet fixed. It was always my Bette noir. I know trace liked MDF for cabs as they thought it sounded better than Chioboard or ply. That was from one of the engineers there not the marketing dept.

[Phil Starr]

[quote name='Chienmortbb' timestamp='1445727084' post='2893784']
Glad you got Black Velvet fixed. It was always my Bette noir. I know trace liked MDF for cabs as they thought it sounded better than Chioboard or ply. That was from one of the engineers there not the marketing dept.
[/quote]It does sound better but it is soooo heavy and if it gets wet it expands and breaks down so it isn't a practical material for instrument cabs really IMO.

[Phil Starr]

There's a parallel thread going on in the Southwest bass bash where the general opinion is that B sounded better because of the extra mids. This is based on people trying it out themselves rather than on the two recorded snippets. As the person who designed the cab I'm thinking 'I should have designed the resonances out' which is interesting. Any engineer is going to be tempted to go on trying to get things 'right' but an instrument cab needs to be 'musical' first and foremost.

The differences between the cabs aren't that great and Stevie is continuing to run tests, we are going to fiddle with the cab stuffing a little but I think we are almost there and will start to write up the design this week.

[Beer of the Bass]

So was recording B the 12mm with bracing?

[Thunderpaws]

Phil, at some point in this thread I remember you hinted you were going to try and drop the volume of the cabs. Did you ever get around to doing this?

[JTUK]

Hmmmm there is where I see a problem with people talking about mids... and they want them as they can actually hear themselves,
but then don't actually like the sound solo'd..but hey, that is ok and it works in the mix.

I'd be thinking this is masking up a load of masking.....and at some point people will hear the bass on its own..and if at that point the sound is poor
or not friendly to the ear..??

To me..wrong way to go about this, definitely.

[Phil Starr]

[attachment=203570:1x12 slot port.jpg][attachment=203571:1x12 slot port with amp.jpg]

never did manage to figure out how to do this properly but this should be a pic or two of the finished speaker. There will be a proper grille fitted once I've got the speaker back from Stevie which should lose the home build look of it.

My goodness it worked even if they are quite small.

Edited October 25, 2015 by Phil Starr

[Chienmortbb]

Phil I am impressed. Yes a full metal grille will improve things but that looks nice.

BTW if you double click the pictures that are big enough.

[Phil Starr]

[quote name='Thunderpaws' timestamp='1445780134' post='2894072']
Phil, at some point in this thread I remember you hinted you were going to try and drop the volume of the cabs. Did you ever get around to doing this?
[/quote]

No, but I might try it after I've published this design. I tend to take too many things on, so I've promised myself I'd get this out asap and not start anything new. If Stevie or I come up with anything that improves these cabs we'll simply offer a Mark II design. I may put out the 15 that I've built to use whilst others are trying the prototype 12's too. I also have a 2x10 ready to go. [quote name='JTUK' timestamp='1445781127' post='2894090']
Hmmmm there is where I see a problem with people talking about mids... and they want them as they can actually hear themselves,
but then don't actually like the sound solo'd..but hey, that is ok and it works in the mix.

I'd be thinking this is masking up a load of masking.....and at some point people will hear the bass on its own..and if at that point the sound is poor
or not friendly to the ear..??

To me..wrong way to go about this, definitely.
[/quote]

There is a lot in what you say, It's been the biggest problem in designing a cab for other people. A PA cab is easy, it just has to put out what you put in so you choose your drivers appropriately and optimise the cab and crossover for flat responses.

A single driver instrument cab is much harder. Most people play with highly coloured commercial cabs. Or well voiced if you like the colouring This cab is essentially comparatively flat which is what people asked for, and it has the potential for a lot more high power deep bass, again specified by early contributors. Then people comment about the prominent mids and the boomy sound caused by the flat (ish) mid compared with normal mid suck out and by having more bass at lower frequencies than they expect which then excite room resonances they didn't know about before.

The advantage of a flat cab response is that it is highly responsive to eq. Look at the photo and you'll see I've dialled in an old school frequency response on the Hartke's graphic, left since my last gig with the 12's.

There isn't anything I'd call right or wrong though. It's OK to go for flat and neutral and then use eq and fx to get the sound you want but just as OK to find the perfect speaker to go with your perfect bass and amp to get the sound you want. The second way will probably take a lot of shopping though before you stumble across the right mix.

It might be fun to design an Ampeg voiced speaker from a 2x12 though.