stevie

[quote name='Hobbayne' timestamp='1446199021' post='2897605'] A few years ago, I saw the Bootleg Beatles in Liverpool. [/quote] Whooooaahh - that's uncanny!

[quote name='LukeFRC' timestamp='1446163191' post='2897493'] have you got a commercial bass cab to hand that doesn't sound prominent mids? I wonder if you measured that and your cab side by side you would be able to see on the charts what the other cab was doing that made your build seem "middy" [/quote] I'm afraid not, Luke. I've only got my own 15" - but that also measures flat and doesn't have the bark of this 12. So I'm a bit flummoxed. Having a well-thought-of 12" cabinet for comparison purposes would have made life a lot easier. Those simulations you linked to mostly show speakers with a falling response towards the midrange. The Basschat 12 doesn't do that, but it's easy enough to produce that kind of sound balance with your preamp. When I pull the 500Hz area down with my amp, I get 'my' sound (not a Trace smiley-face sound - I like plenty of mids). So I don't want to over-emphasise this.

[quote name='EssentialTension' timestamp='1446147872' post='2897379'] Some people said the same about The Eagles themselves. [/quote]

I know some of you guys play in tribute bands, but I wondered how many of you have seen a band called the Dutch Eagles. I've never seen any other tribute band come as close as they do to recreating the sound of the original band. Not only do they have the music and the voices down pat, but they have the accents down too, which is rather an impressive feat as they are singing in a foreign language. [media]http://www.youtube.com/watch?v=6d1SbC0Jly4[/media]

Indeed! You were in fact the one who made me write "near unanimous". It's so easy to be bamboozled by what you hear - measurements are more reliable most of the time. Except that I'm still hearing prominent mids from this cab, which the measurements are not showing. Pulling back around the 500Hz mark takes out the "boing" overtone that I've also heard with some other 12" cabs. I was going to calculate a filter to put a notch in the frequency response, but as nobody else seems particularly bothered, I'm going to leave it alone.

Sounds like a plan. I've often used the Beta 12 in PA cabs before because it handles voice very well, but I've no direct experience of it with bass guitar. I wouldn't really expect it to come close to the Beyma - but it is quite a bit cheaper.

Just a final note. I've modelled what you'll get with a variety of other popular bass guitar drivers in this cabinet: These are: Red: Beyma SM212 Orange: Kappalite 30120HO Yellow: Faital PR300 Blue: Celestion BN12 300X Green Eminence Beta 12a Apart from the Eminence, which exhibits mild peaking at 100Hz, the others are very close below 200Hz in this cabinet. Naturally, there will be differences in the midrange and in matters such as power handling. As I have an Eminence Beta 12a here, I measured its response in this very same cab. I have to say, it looks rather good.

Although this is only at a few watts, the distortion measurement is still very impressive.

Here's the impedance curve of the slotted port version. The cab is tuned to about 46Hz, a bit lower than the first tube-ported version.

This is the anechoic frequency response of the cab - in other words, the response of the cabinet excluding the room reflections. Because of the size of my measuring space, it's only valid down to 300Hz. To measure lower than that, I need to go outside, measure the LF response, and then stitch that to my 300Hz+ measurement. Unless you have an anchoic chamber, everyone uses this method, or a variant of it, to get a full range curve. With the weather as it is, this is not going to happen today. However, I did carry out an RTA measurement with the cab on the floor (how it will actually be used), which tells us what we need to know.

Phil, a peak like that followed by a dip is invariably a resonance. Located just under 1kHz as it is, I'm pretty sure it is a surround resonance.

[quote name='Beer of the Bass' timestamp='1446056120' post='2896579'] Just to help square things up with what we're hearing on the recordings, can you remember which cab had the healthy one? [/quote] Yes, the cabinet (on the left, for those who were there) made up in 1/2" ply had the good driver in. Most people (including me) seem to prefer this one from the recordings. On the other hand, there was near unanimous agreement at the Bash that the other one sounded better. The only explanation I have for this (and I wouldn't bet my life on it) is that we were all listening well off axis at the Bash, i.e. we were all quite close to the cabs. So the peaks would have been much lower in level than in the recordings, which were made directly in front of the cabs. There was also a substantial amount of "panel talk" coming from the 1/2" cab that the close micing would not necessarliy have picked up.

I would have posted this a lot earlier but I hit a snag. When I started measuring one of the cabs I have here, it didn’t measure the same as the one I had had here a few weeks ago. I spent hours trying to figure out what was going on. I even started recalibrating all my measuring gear. Eventually, I pulled out a speaker that I know measures flat and tried it: it was flat. The penny dropped and I put the second cab on the bench and measured it. There was a problem with one of the Beymas. This makes a bit of a mockery of our comparison test at the Bash. This is how they measured. I’d say one of those was definitely not to spec. The red one is the good one, by the way. More to follow shortly.

Adding to what could be Basschat's longest Feedback thread........ Nik bought a speaker from me last week and was a pleasure to deal with.

I also preferred B from those recordings, and I preferred the Italian amp at the time. I think preferences were evenly split at the Bash as far as I could tell. It's going to be interesting listening to the Basschat 12s.

I'm pleased to learn my memory isn't playing tricks on me.

Well I know which one I prefer here, although I thought the difference was more marked on the day.

Graham T kindly had collected 2 prototype cabs from Phil and taken them along to the bash. I set them up side by side and invited people to compare them - without telling them what the difference was. In fact, the first one was built from 1/2" ply, fully braced (with tubular ports). The second was in 3/4" ply with no bracing (with a slot port). Phil had previously told me that he preferred the 3/4" ply version and most of those who listened on the day stated a preference for the 3/4" ply cab, with only one person preferring the other one. The sound difference was not considered to be huge but it was definitely there. Woodinblack made a recording of the two cabs. When he puts them up, everyone will be able to compare them and also get an idea of what they sound like. Most people thought the cabs were well balanced, even though I specifically mentioned our concern that the mids might be too forward. Only two people said they would prefer less midrange, although several said they thought the cabs would benefit from a tweeter. Let's see what the general consensus is when people hear the recordings. If it's generally favourable, we'll move on quickly to drawings, photos, measurements, etc. so that anyone who wants to can get building.

For what it's worth, I've spray painted metal speaker grilles with Hammerite and Platikote spray paints. They both give a professional finish that looks just like powder coated, although it's not as tough. It's tough enough though and certainly tougher than a can of car spray paint (which I'd be reluctant to use here). I expect that using either of these paints to spray over an existing painted or powder coated grille would work, but it would be advisable to spray the back of the grille first just to make sure.

What a lovely bunch of guys - and such a phenomonal selection of gear to try out. From a sixties P-bass (and lots of Fenders), to Lakland, Warwick, Stingray, Status, Ibanez, G&L plus quite a few custom builds. There was even an Ashbory. Amp brands included Trace, Genz, Markbass, Warwick, Barefaced and Ashdown. The DIY community was represented by Jim's Fearful 15/3 and a couple of prototype Basschat 1 x 12s. Thanks to everyone who brought their gear along and also to Jim for doing the organising. The Italy vs. Indonesia match took place and was recorded for posterity. I would venture to claim that they were clearly not the same, but have a listen when the audio files are posted and make up your own mind. Woodinblack also recorded the Basschat 12s, which I am looking forward to hearing when he puts them up. It was not long enough, I'm afraid, as I didn't get a chance to try everything I wanted. Maybe next year.......

I've no experience with the 15 but judging from the spec sheet, it should sound similar to the 12. Definitely not just a woofer; the treble is there but it's not extended.

I take it you're referring to the 12" driver(?). It's got enough HF for most people but I'd describe its sound as 'warm'. It you want tweetery type top end, it hasn't got it. It's fine as a standalone speaker but you're not going to sound like Marcus Miller.