Abm 2x10

[buff]

Ive got a older type abm 2x10. In recent recording's it showed up to have a breaking up speaker at low volumes, unless i cut the bass on the amp back. Its fitted with the old blue type speaker's, any sugestion's ?

[stevie]

[quote name='buff' post='822149' date='Apr 28 2010, 04:48 PM']Ive got a older type abm 2x10. In recent recording's it showed up to have a breaking up speaker at low volumes, unless i cut the bass on the amp back. Its fitted with the old blue type speaker's, any sugestion's ?[/quote]

That's a very nice cab, made of 3/4" birch ply. It would be worth replacing the drivers with something better. Celestion's range of 10s is hard to beat at the moment. You pay a premium for the weight-saving properties of the neo speakers, but many people think it is worth it. Get some BAF wadding to damp the interior of the cab and cut down on the midrange 'honk'. If it were me, I would also add some bracing between the middle of the fromt baffle (between the drivers) and the back panel.

Ferrite drivers:
Fane Sovereign 10-275
CelestionBL10-200X

Neo drivers:
Celestion NTR10-2520E (if price is not an issue)
Celestion BN10-200X/300X

I've just returned from a week's holiday in your part of the world. That St. Austell beer is world class!

Edited April 30, 2010 by stevie

[Mr.T]

[quote name='buff' post='822149' date='Apr 28 2010, 04:48 PM']Ive got a older type abm 2x10. In recent recording's it showed up to have a breaking up speaker at low volumes, unless i cut the bass on the amp back. Its fitted with the old blue type speaker's, any sugestion's ?[/quote]

You should have bought my neo loaded ABM2x10........

[acidbass]

I've recently received two replacement Blue Line drivers (with black cones) for my Ashdown ABM combo - the guy (his name is actually Guy) was very helpful and it only cost me around £40 for both of them including carriage!

[Protium]

The dimensions IIRC are pretty good for a pair of Eminence beta 10 or deltalite 2510, but would probably need the port tuning changing.

[stevie]

[quote name='acidbass' post='824878' date='May 1 2010, 02:42 PM']I've recently received two replacement Blue Line drivers (with black cones) for my Ashdown ABM combo - the guy (his name is actually Guy) was very helpful and it only cost me around £40 for both of them including carriage![/quote]
That's good - how did you manage it?

[Phil Starr]

First of all it can be difficult to pin down exactly where a spurious noise comes from in a speaker. anything loose in the cab might make a strange sound. Check that the speaker is screwed down tight and that nothing in the cab is loose even a loose cable inside the cab can rattle check the grille too. Then check the speaker itself, the glues that hold it together can break down with age The dust cap in the middle is most likely to go followed by the joint between the surround and cone. These can be successfully stuck back with copydex which is a latex based adhesive.

If the speaker is blown contact Ashdown who seem to be pretty good on after sales care.

If after all this you want to replace the speakers be aware that you can't just drop any speaker into any cab and expect the bottom octave to be any good. Each speaker needs to be in a box of optimum volume depending upon the weight and stiffness of the cone and the size of the magnet and coil. in addition a ported cab has to be tuned to the speaker with a fair degree of accuracy. The Fane 10-275 for example needs a smaller cab than the Celestion BL10.

I've got reservations about the Celestion bass speakers (BL and BN) because of their restricted Xmax and the high resonant frequencies (based entirely on their specs). Stevie do you have any experience with these speakers as I am curious as to how they sound?

[LawrenceH]

[quote name='Phil Starr' post='824996' date='May 1 2010, 05:37 PM']I've got reservations about the Celestion bass speakers (BL and BN) because of their restricted Xmax and the high resonant frequencies (based entirely on their specs). Stevie do you have any experience with these speakers as I am curious as to how they sound?[/quote]

The Celestion Xmax figures are not comparable to (e.g.) Eminence or B&C, they are more conservative as they use a different method to arrive at the figure. They calculate Xmax the old way, which is (Voice coil winding width - gap height)/2. Alexclaber has posted figures showing that, for comparison to Eminence drivers (and presumably other manufacturers such as B&C), a more accurate calculation would be (Voice coil winding width - gap height)/2 + (Gap depth/4). This gives much more respectable numbers which I understand equate better with real-world performance.

The Celestion BN10300X has a whopping Xmax of 6mm using this method, while even the Orange label series have Xmax of 4mm, directly comparable to a Deltalite II. The NTR10-2520E gives 6.75mm, making it on paper probably the best option on the market for really tight true bass from 10" drivers. The Celestion 10" units have notably lower Vas values than the Eminence Deltalite II, and combined with the high extension capabilities this means (at least for the green label and NTR) that you can put them in a smaller box and get reasonable bass, or you can put them in a big box with a low port tuning to extend the low end and they'll still be limited by thermal constraints rather than Xmax.

Some B&C drivers give similar performance to the Celestions but are more money. I am hoping to do a DIY ultra-compact 1x10" build using Celestions, a bit like the one posted on here a few days ago but out of 12mm lightweight ply. I'll go with either the BN10300X or NTR10-2520E depending on funds and deciding whether I prefer the more balanced tonality of the NTR. Having said that, I do wonder how good the Orange label might sound with their extended top end - surprisingly nice, I'd bet, despite the (relatively) restricted low-end capability.

Edited May 2, 2010 by LawrenceH

[Phil Starr]

[quote name='LawrenceH' post='825507' date='May 2 2010, 02:07 PM']The Celestion Xmax figures are not comparable to (e.g.) Eminence or B&C, they are more conservative as they use a different method to arrive at the figure. They calculate Xmax the old way, which is (Voice coil winding width - gap height)/2. Alexclaber has posted figures showing that, for comparison to Eminence drivers (and presumably other manufacturers such as B&C), a more accurate calculation would be (Voice coil winding width - gap height)/2 + (Gap depth/4). This gives much more respectable numbers which I understand equate better with real-world performance.

The Celestion BN10300X has a whopping Xmax of 6mm using this method, while even the Orange label series have Xmax of 4mm, directly comparable to a Deltalite II. The NTR10-2520E gives 6.75mm, making it on paper probably the best option on the market for really tight true bass from 10" drivers. The Celestion 10" units have notably lower Vas values than the Eminence Deltalite II, and combined with the high extension capabilities this means (at least for the green label and NTR) that you can put them in a smaller box and get reasonable bass, or you can put them in a big box with a low port tuning to extend the low end and they'll still be limited by thermal constraints rather than Xmax.

Some B&C drivers give similar performance to the Celestions but are more money. I am hoping to do a DIY ultra-compact 1x10" build using Celestions, a bit like the one posted on here a few days ago but out of 12mm lightweight ply. I'll go with either the BN10300X or NTR10-2520E depending on funds and deciding whether I prefer the more balanced tonality of the NTR. Having said that, I do wonder how good the Orange label might sound with their extended top end - surprisingly nice, I'd bet, despite the (relatively) restricted low-end capability.[/quote]

I wondered if anyone would pick this up. The alternatives are to measure the phsical dimensions of gap and coil os Celestion do or to measure the excursion at a set level of distortion, usually 10% which is where it starts to be audible. How quickly the sound becomes compressed as the coil leaves the magnetic field does depend upon the relationship between coil and magnet depth as well as gap geometry. I don't care much about which method is quoted but it would be nice if everyone stuck to the same method so we can make comparisons. Using Alex's method gives Xmax of 3mm for the Celestion BN10300 by the way. I'm hoping you go for the Celestion BN Lawrence. I can't believe Celestion of all people haven't tried out their designs but it is so off the wall to make a bass speaker that has a resonance at 77.9Hz and a much higher f3 in a cab that I chickened out of trying it and went for the Fane10-275 in my latest cab. It gives a lovely tight controlled sound but won't set the world on fire without a livelier top end.

[LawrenceH]

[quote name='Phil Starr' post='826377' date='May 3 2010, 12:39 PM']I wondered if anyone would pick this up. The alternatives are to measure the phsical dimensions of gap and coil os Celestion do or to measure the excursion at a set level of distortion, usually 10% which is where it starts to be audible. How quickly the sound becomes compressed as the coil leaves the magnetic field does depend upon the relationship between coil and magnet depth as well as gap geometry. I don't care much about which method is quoted but it would be nice if everyone stuck to the same method so we can make comparisons. Using Alex's method gives Xmax of 3mm for the Celestion BN10300 by the way. I'm hoping you go for the Celestion BN Lawrence. I can't believe Celestion of all people haven't tried out their designs but it is so off the wall to make a bass speaker that has a resonance at 77.9Hz and a much higher f3 in a cab that I chickened out of trying it and went for the Fane10-275 in my latest cab. It gives a lovely tight controlled sound but won't set the world on fire without a livelier top end.[/quote]

To confuse things even further, quoting directly from Beyma driver PDF:
"The Xmax is calculated as: (Lvc - Hag)/2 + Hag/3.5, where Lvc is the voice coil length and Hag is the air gap height"

So nearly the same formula as Alex's but will give an even more generous Xmax figure! While B&C quote an alternative figure they term Xvar (and give a good justification as to why that value is preferable). I start to wonder if Xlim divided by two might be a better rough and ready comparison. Any idea what Xlim is for the Celestions?

Btw I think you're getting a bit mixed up with your model names - both the Green label neos and the Orange label start with BN, with X at the end denoting Green label and S denoting Orange. For the Orange label BN10-300S, Gap height = 8mm & Voice coil winding width = 12mm so using Alex's method you get an Xmax of 4mm or using Beyma's method you get 4.29mm. For the BN10-300X, Gap height = 8mm and Voice coil winding width = 16mm so the respective numbers are 6mm and 6.29mm.

I think with the Orange label 10" units they're best off in a 2x10" configuration on top of a nice fat 15" unit. But on their own you could always tune them below their resonant frequency in a bigger box. The real issue then is how much power the particular bass playing through them actually outputs below 100Hz, so at what overall playing volume you're going to be excursion limited. After all, a bass doesn't output sine waves! I suspect from my Jazz it's going to be higher than one might at first imagine, especially when emphasising the bridge pickup. On (e.g.) a P there'll be a lot more around 80Hz, but I don't play a P!

However, I just noticed the NTR10-2520D, which is similar to the E unit but with a shorter voice coil, trading Xmax (still very respectable at 6mm (Alex's method)) against sensitivity and upper end response. In WinISD it models out almost exactly the same at the bottom end as the NTR10-2520E, so of course it exceeds Xmax at a slightly lower wattage, but since it's effectively thermally limited before that'll become a real issue anyway, I reckon this is definitely worth it for the enhanced sensitivity and HF. I'm guessing the NTR will sound a lot clearer than the Green label with less distortion and less power compression, hence louder too - best of all worlds. I think that's the unit I'll use! Since I'm only looking at a 1x10" unit initially then skimping on the driver seems pointless, and it'll still come in much cheaper than an equivalent commercial cab

Edited May 3, 2010 by LawrenceH

[Bill Fitzmaurice]

Eminence has been using Klippel Analysis to measure xmax on their drivers for about four years. It's defined as excursion at 10% THD. It's a far more valid method than coil depth/plate thickness methods, which are neither accurate nor consistent. For instance, in the case of under-hung coils that method gives an xmax of zero.
Comparing the Klippel versus coil/plate figures on Eminence drivers the Klippel figure runs about 15% higher. Using that standard the BN10300S would come in around 2.5mm, and the NTR-10 2520D around 4.9mm.

As to why Klippel is not universally employed it's simply a matter of the manufacturers not buying the gear.

[LawrenceH]

[quote name='Bill Fitzmaurice' post='826910' date='May 3 2010, 10:33 PM']Eminence has been using Klippel Analysis to measure xmax on their drivers for about four years. It's defined as excursion at 10% THD. It's a far more valid method than coil depth/plate thickness methods, which are neither accurate nor consistent. For instance, in the case of under-hung coils that method gives an xmax of zero.
Comparing the Klippel versus coil/plate figures on Eminence drivers the Klippel figure runs about 15% higher. Using that standard the BN10300S would come in around 2.5mm, and the NTR-10 2520D around 4.9mm.

As to why Klippel is not universally employed it's simply a matter of the manufacturers not buying the gear.[/quote]

Thanks for an interesting reply Bill - it's funny that the Eminence come out so low in terms of difference between the two methods, compared to (for example) B&C drivers such as the 10NW64 - they claim a one-way Xmax of 8mm measured by the Klippel method, whereas the Celestion method would give 4mm and Alex's would give 6mm. So in this case the Klippel method runs 100% higher and even Alex's method is quite conservative in comparison. For the NDL64, equivalent figures are 6, 3 and 5, whereas the 12" NW100 gives 9, 6 and 9.5.

In the absence of properly equivalent measurements, and based on nothing but subjective experience of Celestion PA drivers being very good, clean performers, I'd bet that the NTRs run closer to the B&C end of the scale, and Alex's guesstimate formula, than to 15% extra. In theory I should be able to compare directly (albeit subjectively) at some point since I have a Deltalite II 2510 kicking around.

[stevie]

[quote name='Phil Starr' post='824996' date='May 1 2010, 05:37 PM']If after all this you want to replace the speakers be aware that you can't just drop any speaker into any cab and expect the bottom octave to be any good. Each speaker needs to be in a box of optimum volume depending upon the weight and stiffness of the cone and the size of the magnet and coil. in addition a ported cab has to be tuned to the speaker with a fair degree of accuracy. The Fane 10-275 for example needs a smaller cab than the Celestion BL10.

I've got reservations about the Celestion bass speakers (BL and BN) because of their restricted Xmax and the high resonant frequencies (based entirely on their specs). Stevie do you have any experience with these speakers as I am curious as to how they sound?[/quote]

I’m not really a great believer in optimum cab sizes. Ported cabs for bass guitar are quite flexible in terms of what works. For example, all the speakers I listed will work quite nicely in a 35-litre cab although, as you mention, the Fane is more comfortable in a smaller cab than the pressed steel Celestions.

In response to your question, I haven’t got a lot of personal experience of the Chinese Celestions. I’ve tried a couple (not the bass guitar ones), and they were better than I expected - certainly better than the older Celestion PA speakers I have tried. Other people I know have been impressed with them. Whoever is designing their drivers is very capable. I’m impressed, for example, with the way the top end is very controlled – unlike many drivers which go into uncontrollable spasms before they roll off.

I understand what you mean about the high resonant frequencies. 73Hz does sound too high, although this is largely a factor of the suspension stiffness. Also, the Qts of this driver is relatively high, which compensates. You could drop the resonant frequency by fitting a softer suspension, but then Qts would drop, VAS would rise and you’d end up with exactly the same performance. I modelled the two pressed steel chassi Celestions, one with 73Hz and the other with 64Hz resonant frequency and their low frequency performance was identical.

If I were choosing from the three pressed steel drivers based on their parameters, I’d go for the Fane as you did because the heavier cone helps it produce more bottom end. Oddly enough, the parameters of the Celestion NTR driver are very close to those of the Fane. Although the NTR is a very expensive option, it is probably in the same class as B&C, 18Sound and Beyma.

4mm coil overhang is quite acceptable for a 10 - even the JBL 2226 only has 5.5mm of physical overhang. If it were a B&C or an Eminence, the spec sheet would say 8mm xmax.

What do you think the problem is with the top end of the Fane, Phil? Have you measured it?

[btp]

Hi all,
This thread seems to have attracted some very knowledgable people and I am hoping for a little advice.

I've got a cabinet loaded with 2 Celestion BN10-300x -- it's a 3-way Dr. Bass 2060 slant face, with a 6" eminence mid and a selenium tweeter. Very nice cabinet. However, one of the Celestion drivers seems to be farting out a little, even at modest volume. I've inspected for obvious problems (loose bits of insulation, etc.), and everything looks OK. Also, in the process of troubleshooting this, I noticed that the frequency response does indeed roll off somewhat below low E. Not surprising, of course.

So I am wondering if I should:

1) Replace that one Celestion driver, and live with the frequency response issue?
2) Replace both Celestions with some other driver (neo preferred, but doesn't have to be...), in the hopes of extending the frequency response?
3) Do something entirely different that I haven't imagined yet...?

The cabinet has a shelf port (not tubes), so there's really no way to extend/change it. And with the 3-way cabinet, the mids are well-represented already... so drivers with nice bright mids are not necessary here.

Thoughts?

Thanks!!

[Bill Fitzmaurice]

[quote name='btp' post='939735' date='Aug 29 2010, 08:47 PM']I've got a cabinet loaded with 2 Celestion BN10-300x -- it's a 3-way Dr. Bass 2060 slant face, with a 6" eminence mid and a selenium tweeter.[/quote]
With the mids afforded by the 6" mid using high Fs tens is a very odd choice. I'd be looking at replacing them with long excursion tens with Fs between 35 and 45 Hz. Eminence will have some in the yet to be announced 3010 series, but those being at least 6 months down the road, perhaps a year in the UK, I'd look around for alternatives if you don't want to wait.

[btp]

[quote name='Bill Fitzmaurice' post='939747' date='Aug 29 2010, 09:34 PM']With the mids afforded by the 6" mid using high Fs tens is a very odd choice. I'd be looking at replacing them with long excursion tens with Fs between 35 and 45 Hz. Eminence will have some in the yet to be announced 3010 series, but those being at least 6 months down the road, perhaps a year in the UK, I'd look around for alternatives if you don't want to wait.[/quote]

Thanks for the tip! Just speaking for myself, I have always been very grateful for your on-line participation (e.g., on Talkbass and elsewhere). You're Global, dude! If the 3010 is anything like the 3015, it should be worth waiting for. As for myself, I'm actually in N. America, so finding a replacement BN10-300x isn't so easy, anyway.

[stevie]

[quote name='btp' post='939735' date='Aug 30 2010, 01:47 AM']1) Replace that one Celestion driver, and live with the frequency response issue?[/quote]
That's the obvious, easiest and cheapest option.
[quote name='btp' post='939735' date='Aug 30 2010, 01:47 AM']2) Replace both Celestions with some other driver (neo preferred, but doesn't have to be...), in the hopes of extending the frequency response?[/quote]
Assuming the cab is already on the floor, the easiest way of extending the bass response is to use your tone controls. The only other way is of getting more bottom end out of the cabinet is to use lower sensitivity bass drivers, which in practical terms amounts to the same thing. If you do that, however, the mid and HF will then be unbalanced. It's not a good idea.
[quote name='btp' post='939735' date='Aug 30 2010, 01:47 AM']3) Do something entirely different that I haven't imagined yet...?[/quote]
If you think you are overpowering the bottom end of your existing cabinet (which might explain the damaged driver), it could be that you need another cabinet to support the bottom end when you are playing at volume.

[btp]

[quote name='stevie' post='942810' date='Sep 1 2010, 06:16 PM']If you think you are overpowering the bottom end of your existing cabinet (which might explain the damaged driver), it could be that you need another cabinet to support the bottom end when you are playing at volume.[/quote]

Thanks for the suggestion. I'm using a shuttlemax, which produces 600W into 4 ohms, which is how the two celestions are wired. So it's 600W RMS into a 600W RMS cabinet. I suppose by some people's thinking, it might actually be underpowered, yes? But the shuttlemax has a little clip light that comes on, and I believe it has a kind of peak-limiting compression that kicks in, rather than just clipping the signal. And I just about never let that light come on, anyway -- I just don't play that loud. So it's a little mysterious and disappointing that it would be damaged.

But I think perhaps Bill Fitz has put his finger on the low end issue -- the BN10-300x speakers have their resonant peak Fs around 64Hz. So by the time they get down to low E (around 40Hz), it's rolling off, and the by the time they get to low B (closer to 30), it's really weak.

I was actually looking at the Eminence Legend BP102 -- they have a really low Fs (35Hz), high xMax, but a little less power handling, a little heavier, but MUCH cheaper... two of them would cost the same as one Celestion, if I could even locate one...

[Bill Fitzmaurice]

[quote name='btp' post='942902' date='Sep 1 2010, 07:50 PM']I was actually looking at the Eminence Legend BP102 -- they have a really low Fs (35Hz), high xMax, but a little less power handling, a little heavier, but MUCH cheaper... two of them would cost the same as one Celestion, if I could even locate one...[/quote]
BP102s are great drivers at a low price, but they aren't good full range. Crossed over to a 6 inch mid no worries.

[Phil Starr]

[quote name='stevie' post='828509' date='May 5 2010, 03:11 PM']I’m not really a great believer in optimum cab sizes. Ported cabs for bass guitar are quite flexible in terms of what works. For example, all the speakers I listed will work quite nicely in a 35-litre cab although, as you mention, the Fane is more comfortable in a smaller cab than the pressed steel Celestions.

In response to your question, I haven’t got a lot of personal experience of the Chinese Celestions. I’ve tried a couple (not the bass guitar ones), and they were better than I expected - certainly better than the older Celestion PA speakers I have tried. Other people I know have been impressed with them. Whoever is designing their drivers is very capable. I’m impressed, for example, with the way the top end is very controlled – unlike many drivers which go into uncontrollable spasms before they roll off.

I understand what you mean about the high resonant frequencies. 73Hz does sound too high, although this is largely a factor of the suspension stiffness. Also, the Qts of this driver is relatively high, which compensates. You could drop the resonant frequency by fitting a softer suspension, but then Qts would drop, VAS would rise and you’d end up with exactly the same performance. I modelled the two pressed steel chassi Celestions, one with 73Hz and the other with 64Hz resonant frequency and their low frequency performance was identical.

If I were choosing from the three pressed steel drivers based on their parameters, I’d go for the Fane as you did because the heavier cone helps it produce more bottom end. Oddly enough, the parameters of the Celestion NTR driver are very close to those of the Fane. Although the NTR is a very expensive option, it is probably in the same class as B&C, 18Sound and Beyma.

4mm coil overhang is quite acceptable for a 10 - even the JBL 2226 only has 5.5mm of physical overhang. If it were a B&C or an Eminence, the spec sheet would say 8mm xmax.

What do you think the problem is with the top end of the Fane, Phil? Have you measured it?[/quote]
Hi Stevie, I lost track of this thread over the Summer what with gigs and holidays. Yeah I also modelled the two Celestions. I haven't got round to measuring the Fane yet. In the end I couldn't make my mind up between the Fane 10-275 and the 10-125 so I bought two of each to experiment with and built them into a temporary 4x10 but with a partitioned cab and wired as two 2x10's. The Fane data shows a more extended top end for the lighter coned 10-125 with a smoother break up pattern and this is the speaker Fane recommend for bass guitar but because I have come from a hi fi direction I was attracted to the cleaner bass promised by the low Q and bigger magnet of the 10-275.

So, I effectively have two 2x10's with the 10-125's in undersized cabs tuned to 55Hz and the 10-275's in optimum cabs (SBB4). the only testing I've done so far is to play bass through them.

Firstly I'd confirm what you say about optimum cab size. The modelling on the undersized cab shows a real hump of just under 3dB (from memory) but the bass sound when playing isn't dramatically different from the 10-275's. Certainly much less than that caused by tweaking the eq or changing strings

The 10-275's do give a more clean and controlled bass, but again it isn't dramatic. I doubt that it would be noticeable once the band get playing around me. They also roll off at about 3000Hz and their is no dramatic resonance peak unlike the Celestions or equivalent Eminence speakers so they don't sound particularly lively and I play with my 15" Peavey driven cab on top to pick myself out of the mix the 10-275's are very bassy and the Peavey gives a lot more mids. Finally they weigh a ton and a 4x10 with these in will be a hell of a lift. They do make for a nice small box though.

I'm not the worlds greatest bassist so the speakers haven't had much of a workout yet. I'm going to do some measurements and try out an optimum sized 2x10 with the 10-125's which sound better than I expected in the undersized cabs. I'm also intending trying the 10-275's in a 2x10 on their own to see if they are up to the job as a compact cab. My wife is going to kill me.