Speaker recommendations

[john_the_bass]

I searched for 'Speaker +recommendation' and only got half a page of results that weren't what I was looking for and then searched 'speaker' and got 26 pages so I'm going to ask

The speaker in my Ashdown ABM Mini 15 stopped working rather abruptly last night. Low input, output set to about 1 o'clock, not had much use - certainly less than 100 hours anyway.
It's well past its warranty now, so I will need to buy a replacement 15" speaker. Can anybody recommend a brand or type for somebody on a budget?

[Stylon Pilson]

Contact Ashdown [url="http://www.ashdownmusic.com/tech/tech_service.asp"]here[/url]. They'll let you know how to get hold of a replacement. If you just drop in any old random 15" driver, you may not get a nice sound. Let them know that it's only had 100 hours and you weren't pushing it hard - they might waive the warranty and replace it for you.

S.P.

Edited July 1, 2009 by Stylon Pilson

[john_the_bass]

That's a good plan - I did speak to them this morning and they were very helpful. I might try again

[john_the_bass]

And if anybody can offer any suggestions on how I remove the speaker from the cab, they would be welcomed. I have removed the screws but the bloody thing won't budge. Trying to run a fuel loyalty points club card underneath the edge of the speaker frame results in destroying the card!

[Mr. Foxen]

[quote name='john_the_bass' post='529399' date='Jul 1 2009, 10:13 AM']And if anybody can offer any suggestions on how I remove the speaker from the cab, they would be welcomed. I have removed the screws but the bloody thing won't budge. Trying to run a fuel loyalty points club card underneath the edge of the speaker frame results in destroying the card![/quote]

They are well stuck on, I pryed the 12 out of my combo with a screwdriver. Satisfying crack/pop sound.

[soopercrip]

[quote name='john_the_bass' post='529399' date='Jul 1 2009, 09:13 AM']And if anybody can offer any suggestions on how I remove the speaker from the cab, they would be welcomed. I have removed the screws but the bloody thing won't budge. Trying to run a fuel loyalty points club card underneath the edge of the speaker frame results in destroying the card![/quote]



[attachment=28063:77059888...8hotsaw1.jpg]

[john_the_bass]

[quote name='Mr. Foxen' post='529458' date='Jul 1 2009, 11:51 AM']They are well stuck on, I pryed the 12 out of my combo with a screwdriver. Satisfying crack/pop sound.[/quote]

That's what I did in the end - flipping thing.
No response from the good people at Ashdown but it's only been a few hours!

[Hamster]

[quote name='Mr. Foxen' post='529458' date='Jul 1 2009, 11:51 AM']They are well stuck on, I pryed the 12 out of my combo with a screwdriver. Satisfying crack/pop sound.[/quote]

I've used det cord to cut holes in things before, but a screwdriver might be easier if you want to re-use the cabinet, amplifier, speaker or living room again

[hubrad]

If none of the above works (I like the last pic ) Beneath It All is selling some speakers, including a 15":

[url="http://basschat.co.uk/index.php?showtopic=51697&hl=chassis+speaker"]http://basschat.co.uk/index.php?showtopic=...chassis+speaker[/url]

[john_the_bass]

Cheers for tip off but really need another (at least) 300w 8ohm 15"

Edited July 1, 2009 by john_the_bass

[martinbass7750]

[quote name='john_the_bass' post='529362' date='Jul 1 2009, 09:37 AM']I searched for 'Speaker +recommendation' and only got half a page of results that weren't what I was looking for and then searched 'speaker' and got 26 pages so I'm going to ask

The speaker in my Ashdown ABM Mini 15 stopped working rather abruptly last night. Low input, output set to about 1 o'clock, not had much use - certainly less than 100 hours anyway.
It's well past its warranty now, so I will need to buy a replacement 15" speaker. Can anybody recommend a brand or type for somebody on a budget?[/quote]


Hi John,

Try talking to Lean Business - they stock Celestion at pretty good prices - or Blue Aran who stock Eminence and Fane.

The've both been helpful when I've called them in the past.

[url="http://www.lean-business.co.uk/eshop/index.php?main_page=index&cPath=20"]http://www.lean-business.co.uk/eshop/index...ex&cPath=20[/url]

[url="http://www.bluearan.co.uk/index.php?category=Speaker_Components&masthead=Loudspeaker_Drivers&subheadnew=15_Inch_Drivers"]http://www.bluearan.co.uk/index.php?catego...15_Inch_Drivers[/url]


Cheers

Martin

[stevie]

Snap! I also have an ABM Mini (purchased yesterday from a very nice Basschatter) with a faulty drive unit - just like yours. Mine is only starting to go, as there is no coil rub yet - but it's certainly on its way out. I'm fairly sure that incorrect cabinet tuning is the cause of the failure. My back-of-a-fag packet calculations show the cab is tuned to about 55Hz, which means the speaker will only handle about 10 watts of low E. So, driver failure has been built in and is just a matter of time unless you're using it in your bedroom.

I'll measure the cabinet tuning some time soon, and when I've managed to persuade the driver to come out (I thought it had been glued in!!), get the Thiel Small parameters, which will show us the type of driver they've used. This cab is roughly 45 litres in volume (much smaller than I was expecting), which is much too small for just about every 15 I know - but a good volume for a 12. In other words, there is no benefit in fitting a 15 in here, because a 12 will produce just as much bottom end.

Given the excessive profit margins manufacturers make on spares, I would hesitate to replace the driver with another of the same. A budget, lightweight option would be the Celestion TN neo 12" available for about £50, but you will need to fit a panel of 1/2" birch ply over the front baffle first. The 15" Celestion TN neo costs £25 more but will not actually provide any more bottom end (because of the small cabinet size). Plenty of quality 12" drivers will work in here though.

Bear in mind that the cabinet should definitely be re-tuned lower - or else the same thing will happen again. As long as you're not in a rush, I can post my results from time to time for your guidance. Incidentally, I sent an email to Ashdown yesterday late afternoon (about getting the speaker out) and they responded this morning. Very impressive!

[stevie]

I measured the impedance of the cab, and it is tuned to 50Hz. Too high. We can sort that out by lengthening the ports. I've used Pringles tubes before and they may work again here.

Edited July 2, 2009 by stevie

[stevie]

The frequency response is exactly what you would expect from fitting a speaker in too small a cabinet. The Trace 1153 is similar, although not quite so bad. The measured frequency response starts at 40Hz here and finishes at 250Hz. It's not a pretty sight. The word is boomy.

[stevie]

It can be fixed though, with a bit of jiggery pokery. Ignore the green curve - that's a halfway house. Not bad, eh?

[stevie]

Finally, here is a frequency response curve of the ABM Mini 15 from 200Hz up. It measures quite smoothly and is relatively extended for a 15. Notice in particular the lack of sharp peaks. The waterfall plot isn't quite so nice, although the lack of damping inside the cab doesn't help. Ignore the curve in the top window.

[stevie]

I've measured the Thiel Small parameters of the speaker in the ABM Mini 15 cabinet. Do you want the good news or the bad news, John?

Well, the bad news is that Ashdown have clearly fitted the cheapest driver they could find that will handle 250 watts, stuck it in the box and hoped for the best.
The good news is that the driver is so cheap, it won't cost very much to buy something similar.

For anyone else visiting this thread with the same problem, the basic parameters are:
FS 35Hz
Re 6.7 ohms
Qe .67
Qm 8.7
Qt .62
VAS 287 litres

That should allow anyone to model it should they so desire.

The driver is a Sica Z008190 - says so on the magnet. It is not one of Sica's standard models. However, its specs are similar to the Eminence Beta and Delta 15s. If you want a direct, cheapo replacement you should be able to pick up a second hand one of those for very little money that will sound fairly close to what was in there before. I would warn you, however, that those cheap Eminence drivers have only one thing going for them - they are bombproof. Don't buy new ones though: you should definitely spend a little bit more and get something half decent.

It's such a nice, birch ply cabinet that it would certainly be worth putting something better in it. The Celestion BL15-300X looks quite good. Even better would be a Celestion neo, the TN1530. The two Celestions would both perform better in a bigger cabinet but they will work in the Mini box and sound better than the original speaker.

You need to extend the ports to eight inches either by fitting new ports or by adding some cardboard tube to the existing ones. Also, you should staple some BAF wadding to the walls, which will improve the quality of the midrange. That's it. Good luck.

Edited July 8, 2009 by stevie

[alexclaber]

You're not wrong about that driver! That's exactly the sort that gives 15"s their undeserved reputation for boominess.

Alex

[stevie]

[quote name='alexclaber' post='531227' date='Jul 2 2009, 11:12 PM']You're not wrong about that driver! That's exactly the sort that gives 15"s their undeserved reputation for boominess.[/quote]
Yes, funny that, Alex. The more I find out about equipment for bass players the more I realize that much of it is gloss not substance. I think perhaps a more critical specialist press could help stop manufacturers getting away with the things they do. I notice in Tom Bowlus' online review of 15s, including the small Ashdown, he didn't mention the fact that the Mini 15 has a 6dB peak just over 100Hz - which is a serious design fault. If he noticed, he certainly didn't mention it. Makes you wonder.
Given how much bassists spend on their gear, the cost of a decent driver for their speaker cab is relatively insignificant and would probably make a bigger difference than any other investment they could make.

[bumnote]

[quote name='stevie' post='531105' date='Jul 2 2009, 09:28 PM']You need to extend the ports to six inches either by fitting new ports or by adding some cardboard tube to the existing ones. Also, you should staple some BAF wadding to the walls, which will improve the quality of the midrange. That's it. Good luck.[/quote]

I understand that a company might fit the cheapest speaker it can get away with, but why not port it properly, surely that costs nothing

Edited July 4, 2009 by bumnote

[Bill Fitzmaurice]

[quote name='bumnote' post='532651' date='Jul 4 2009, 04:40 PM']I understand that a company might fit the cheapest speaker it can get away with, but why not port it properly, surely that costs nothing[/quote]Heard the one about a silk purse and a sow's ear?
You can't use a sub-standard driver with a good result no matter what the box tuning. For that matter a driver with a Qts of .62 has no business being in a small ported enclosure in the fist place. It would work reasonably well in a sealed cab of some 15 cubic feet.

[Deep Thought]

I have a pair of ABM Minis with Celestion Neo 12's in them-same size cabinet. I'm delighted with them-I bought them from Nick Carey, who told me they were customised by somebody who does such things, whose name I forget. Drop him a PM and I'm sure he'll fill you in.

[Merton]

Good work Stevie! Like the investigative journalism Very interesting reading, makes me glad I didn't get the Mini15s I was looking at earlier this year

Edited July 5, 2009 by Merton

[Bill Fitzmaurice]

[quote name='Merton' post='532753' date='Jul 5 2009, 03:32 AM']Good work Stevie! Like the investigative journalism Very interesting reading, makes me glad I didn't get the Mini15s I was looking at earlier this year [/quote]
Don't be hard on Ashdown, most lower priced, and more than a few higher priced, combos and separates employ drivers with similar specs. As for a midbass bump, and corresponding lack of low end, that same response characteristic can be found in more than a few high end cabs, Schroeder and Eden among them. Not because they use cheap drivers, but because it makes the cab seem louder. Look at an Equal Loudness Curve to see why.

[bumnote]

[quote name='Merton' post='532753' date='Jul 5 2009, 08:32 AM']Good work Stevie! Like the investigative journalism Very interesting reading, makes me glad I didn't get the Mini15s I was looking at earlier this year [/quote]

didnt we nearly do a trade my mini 15 for your trace?

Bugger It