stevie

I've come across a few underwound pickups in the past on Squiers and Yamahas (to be specific). Replacing them with a proper pickup - usually a Duncan vintage - improved the sound each time. It's not absolutely reliable, but you can try measuring across the windings if you have a meter. The standard resistance is about 10.5k (from memory). Or just try it and see.

The new MiBass combos look really nice. Why does the company have to ruin it by letting Mr Edsel Ashdown go on camera? Try counting the number of times he says 'versatile' - and look out for the highlight of the interview where he tries to remember what year it is - and fails! It starts off with a great bass solo. Not. Why do British companies still think that it's all about being a keen amateur? http://www.youtube.com/watch?v=-iDVXwwyjUU

By the way, there are people on eBay offering spacer rings if you don't fancy doing it yourself. It might have to be a custom size though, as they normally make them for the car audio brigade.

You need to get yourself a sheet of 1/2" MDF and cut spacer rings to bridge the gap. Inside diameter to fit the Eminence drivers - outside diameter about an inch larger than the hole in the cab. You should be able to use the existing screw holes in the cab to screw the spacers down. Glue if you want a permanent job or use foam for a less permanent job. Paint matt black. The drivers will now be 1/2" further forward than the old ones, which is not normally a problem - and you will actually gain a bit of cabinet volume.

There's an awful lot of guff written about bass pickups. On a 'vintage' type pickup like the SPB-1, all the manufacturers are using the same bits and winding to the same specification. You would therefore expect them to sound very similar - and they do. Take a listen here: http://www.atkinsonbasses.com/multimedia.html and see if you can tell the difference between a cheapo GFS P-Bass pickup and a 'booteek' Lollar at many times the price. Pickups that are physically different like the Quarter Pounder will sound different, of course, and cheap pickups that don't use enough wire sound weedy, but otherwise, the emptor should be aware that most of his money is paying for the brand name.

[quote name='ShergoldSnickers' timestamp='1333796707' post='1606560'] I think 4x10 is a format in danger of being left behind. [/quote] Interesting post.

I recently bought a set of these: http://www.ebay.co.uk/itm/270920824395?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649. That's a great price. They are excellent and are now on the bottom of my Ashdown cab. I appreciate the OP was looking for a trolley, but putting castors on the bottom of your combo is an option worth considering.

That all makes sense but it's a separate issue to driver choice. The cabinet should have the equivalent of two ports 4" in diameter. By the same token, jack inputs should ideally be changed for Speakons and the cabinet should be damped and braced at its weakest points. But we're now into the realm of redesigning a cab without knowing anything about it. I'm a great believer in premium drivers. There's no point paying £100 for an adequate driver when you can get a great driver for just £60 more. The Eminence Legend CB158 would work. It's £90 but it's not a patch on the 18sound (and not available in 4 ohms anyway). Still, it is better than the Delta 15LF, although that wouldn't be hard.

2Hz. Do I get a prize?

It's unsafe to assume that Fender knows how to port a bass guitar cab? Just editing this, because I think I see where you are coming from now. Bass guitar cabs are all tuned to around 50Hz, give or take. There is a certain amount of wiggle room - tuning to 40 or 60Hz is not going to make that much difference. The tuning frequency is a characteristic of the cabinet - not the driver. So, when you change the driver, the cab tuning frequency doesn't change. As long as the driver is suitable for the cabinet size it will work. You can therefore fit a variety of different drivers to the same cab and they will all perform. They may sound different but you won't need to change the tuning unless the tuning was badly out in the first place.

If Redlawman is bothered about the tuning I'm sure he'll ask, but he hasn't done. He asked for a driver recommendation. And I think we can safely assume that Fender knows how to tune a bass guitar cab. Why make things more complicated than they need to be?

[quote name='Mr. Foxen' timestamp='1333726600' post='1605806'] Sealed cab? Gogo gadget WinISD pro.[/quote] It's front ported. Redlawman actually mentions this twice. [quote name='Mr. Foxen' timestamp='1333726600' post='1605806'] Edit: Short summary: putting a state of the art driver into a not state of the art cab is a bad plan. Suitable driver for the cab is going to yield better results. [/quote] According to the manufacturer's specs, the driver I mentioned is recommended for a cab between 80 and 140 litres. The cab as described ("largish 15 smaller than an Ampeg 4x10") is within that.

Lean are selling a 4-ohm 18sound *NEO* driver for £160 at the moment - the 15ND830 . It must be old stock because the 8-ohm version is £75 more. The direct link won't copy, but the site is at: http://www.lean-business.co.uk/eshop/. It's a bargain. I've never used it personally but the spec is right and 18sound speakers are state-of-the-art. Very few (if any) commercial bass cabs use a driver of this quality.

[quote name='Coilte' timestamp='1333709292' post='1605504'] This is a good exercise, except for one caveat. OP, this is known as the "one finger per fret technique". It is a very economical way of playing, but be [b]very[/b] careful when applying it to frets 1-5. [/quote] +1. Using one finger per fret near the nut can cause wrist pain if you have small or normal sized fingers. Some teachers advise linking the fourth and fifth fingers together for support and only using one finger per fret up the neck where the frets are closer together. It definitely worked for me. I think Dave Marks has a lesson on his website that discusses this.

On the piezo front, my web researches indicate that you need a unit with a CTS (Motorola) piezo element. It's not always easy to tell, as there are a lot of copies around. The Monacor MPT range seems to use them, as do these ones from CPC, which seem to be quite popular (and cheap): [url="http://cpc.farnell.com/_/mpt-001/piezo-tweeter/dp/LS02371."]http://cpc.farnell.c...ter/dp/LS02371.[/url] There's no harm in using two, but because a bass guitar produces very little energy at these frequencies (unless you play like Markus Miller all the time), you are very unlikely to overload a single tweeter. Two would be more sensitive though.

[quote name='JTUK' timestamp='1333702915' post='1605384'] Would I go back to a 115..? no, The biggest single factor was that it wasn't useable on its own. [/quote] I'm currently using a single 15 and, even though the frequency response is flat to nearly 4k, I find it difficult to hear what I'm playing when I'm up close (for obvious reasons). However, I hate the idea of having to carry four magnets around - so I've added an eight-inch midrange in a separate cab, crossed over at 800Hz. The on-axis frequency response of the pairing is virtually identical to that of the single 15, but subjectively there's a lot more top-end clarity which is audible up close and throws better in-room. I previously used a 2 x 12 which was a lot bigger, but this is a much better solution IMO. There are lots of ways to skin a cat.

You'll find a similar pattern in just about any industry you care to mention. Larger companies have a wide product range; smaller companies have a more limited product range. Do these companies want you to buy more than one of their products? Quite likely.

[quote name='Conan' timestamp='1333655403' post='1605007'] Just because a certain combination sounded "good" doesn't maen that a different combination wouldn't have sounded better. Unless you can to a proper A vs B test with all other factors constant, it's just not a fair test and therefore rather meaningless. If it sounds good to your ears, good - keep using it by all means. But don't diss another set-up of which you have no experience. [/quote] How likely do you think it is that the players using a 15 and 10s have never used a 4 x 10? Of course, they have, but they are happy with what they've got. Nor are they dissing those who choose to use multiples of the same driver. All the shouting is coming from those who insist that you should not mix drivers. I'm waiting for someone to give me a good reason why 15s and 10s don't work. "I tried it once and it sounded sh*t" doesn't cut it, I'm afraid.

[quote name='john the pond' timestamp='1333651253' post='1604926'] Nobody is saying "thou shalt not mix cabs"! But the reasons usually given are false. [/quote] You will notice that the people saying 'I mixed cabs to good effect' are clearly experienced players using good gear. They are saying, almost to a man, I did it and I know it sounded good. So these reasons are false?

What causes phase cancellation is not different driver sizes, it's the spacing between the drivers. So, a 1 x 15 plus 2 x 10 is not going to be any more or less "phase coherent" than two 2 x 10s.

What exactly does this mean?

Paddy stopped cutting the hedge as the big car drew up beside him and an English visitor enquired: "Could you tell me the way to Balbriggan, please?" Paddy wiped his brow. "Certainly, sor. If you take the first road to the left.... no still that wouldn't do..... drive on for about four miles then turn left at the crossroads...... no that wouldn't do either." Paddy scratched his head thoughtfully. "You know, sor, if I was going to Balbriggan I wouldn't start from here at all."

Alternatively, you could also have a word with Ashdown. If they did a tweetered version of the cab they will no doubt be happy to sell you a tweeter and x-over for you to fit yourself. That way, it would still look like an original Ashdown cab. Unlike most, Ashdown spares prices are quite reasonable.

Sorry, I haven't dealt with piezos for years, although I'm aware that there are quite big differences in the brands. The Fitzmaurice cab builders use them a lot and will no doubt be able to advise you. Dave Perry could be your man.