what size cab do ineed for a 50 watt valve head?

[tom skool]

hi i'm new here!
Ive just got myself a 50 watt selmer treble'n'bass head but as its considerably louder than a 50 watt solid state i've got no idea what size cab i need for it.
I tried it out with 15inch 200 watt ashdown cab and that started to fart a bit before i reached half way with the volume. I do like a bit of distort which is why i went for the 50 watt and not the 100 watt but this wasnt particularly nice and i think it was more the speaker complaining. does that seem right?
I've seen a laney r410 thats within my budget which i think is 250 watt. would that extra 50 watt make the difference?
I play mostly pub gigs playing rock/ indie covers and i've managed for years with 150watt ashdown combo but our guitarist is not only deaf but has serious GAS and has ended up with a 100watt fender twin! Although it is switchable to 25watt (yeah right,hes gonna wanna do that!)
Any way i hope some of you can give me some idea of what i need. i hope i havent asked too many questions

cheers
tom

[Adrenochrome]

It's unlikely to be the cab that's farting TBH, though it is possible. My 200w cab handles 200w of input power with no problem. More likley to be the head that's struggling if it's 50w.

[obbm]

[quote name='tom skool' post='274961' date='Sep 1 2008, 09:25 PM']hi i'm new here!
Ive just got myself a 50 watt selmer treble'n'bass head but as its considerably louder than a 50 watt solid state i've got no idea what size cab i need for it.
I tried it out with 15inch 200 watt ashdown cab and that started to fart a bit before i reached half way with the volume. I do like a bit of distort which is why i went for the 50 watt and not the 100 watt but this wasnt particularly nice and i think it was more the speaker complaining. does that seem right?
I've seen a laney r410 thats within my budget which i think is 250 watt. would that extra 50 watt make the difference?
I play mostly pub gigs playing rock/ indie covers and i've managed for years with 150watt ashdown combo but our guitarist is not only deaf but has serious GAS and has ended up with a 100watt fender twin! Although it is switchable to 25watt (yeah right,hes gonna wanna do that!)
Any way i hope some of you can give me some idea of what i need. i hope i havent asked too many questions

cheers
tom[/quote]

Firstly welcome. Seeing that at the time the Selmer was made speakers had rarely more than 50-watt handling, are you absolutely sure that the problem lies with the speaker and not in the amp. It could be that you are just overdriving the amp into distortion. If we knew where you were then maybe some kind and knowledgeable member could lend assistance/try cabs.

BTW you're never going to keep up with a Fender Twin with 50-watts.

[tom skool]

[quote name='Adrenochrome' post='274969' date='Sep 1 2008, 09:32 PM']It's unlikely to be the cab that's farting TBH, though it is possible. My 200w cab handles 200w of input power with no problem. More likley to be the head that's struggling if it's 50w.[/quote]
yeah perhaps but i hadnt even got halfway. I had the volume, it just didnt sound that great more farty than nice overdrive. Being all valve i should be able to drive the hell out of it without any worries right?

[Bill Fitzmaurice]

[quote name='tom skool' post='274979' date='Sep 1 2008, 04:41 PM']yeah perhaps but i hadnt even got halfway. I had the volume, it just didnt sound that great more farty than nice overdrive. Being all valve i should be able to drive the hell out of it without any worries right?[/quote]
The main difficulty with so little power is that it takes a lot of speaker sensitivity to get a lot of clean output. In the simplest terms getting high sensitivity meann using lots of drivers, so a pair of 2x10 at the least is in order. The speaker's power rating is almost meaningless.

[bennifer]

Its totally different with it being an all valve head anyway. For example, a 15w Orange Tiny Terror guitar amp totally screams through a 4x10 and is fine for live on stage stuff. A 15w solid state guitar amp however would only be useful for quiet bedroom practise.

What impedance is the 200w ashdown cab you're using? and at what impedance does the head kick out 50 valve watts at?

Something like a 300-400w cab would be my guess - any chance you can take the head into a well stocked bass shop and try some cabs?

[bass_ferret]

If you dont know what you are doing - dont do it.

This is a specialist subject that most of us are not qualified to talk about never having used a Treble-n-bass. I think that one of the Dobbin's boys has/had one but you will be lucky to get any sense out of them. You might want to have a word with Oxblood over on Finnbass.

[Adrenochrome]

...oh, I was forgetting that tube watts are magically much bigger than SS watts .

Sorry mate but your amp is not powerful enough. Getting more/more sensitive speaker[s] will help get you more volume out of what you've got.

[Musky]

Forgive me if I'm wrong, but 50W rms is 50W rms. Valve amps may sound louder for a given wattage, but if the T&B is accurately rated at 50W that is what the cab will be seeing. A 200 watt cab should be more than enough to cope. If you've not had the opportunity to check the amp with another cab, I'd be inclined to do so. I suspect it's an issue with the amp rather than the cabs ability to handle the wattage.

Edit: I'm sure I've read that others here have bought 50W selmers, but I don't recall any complaints about this kind of distortion.

Edited September 1, 2008 by Musky

[bass_ferret]

[quote name='Adrenochrome' post='275040' date='Sep 1 2008, 10:45 PM']...oh, I was forgetting that tube watts are magically much bigger than SS watts .

Sorry mate but your amp is not powerful enough. Getting more/more sensitive speaker[s] will help get you more volume out of what you've got.[/quote]
Valves sound louder cos they induce compression - which is why lots of compressors have valves in.

[ped]

PM 'Zerofret' the man is a mad Valve monster

[tom skool]

[quote name='bennifer' post='275010' date='Sep 1 2008, 10:16 PM']Its totally different with it being an all valve head anyway. For example, a 15w Orange Tiny Terror guitar amp totally screams through a 4x10 and is fine for live on stage stuff. A 15w solid state guitar amp however would only be useful for quiet bedroom practise.

What impedance is the 200w ashdown cab you're using? and at what impedance does the head kick out 50 valve watts at?

Something like a 300-400w cab would be my guess - any chance you can take the head into a well stocked bass shop and try some cabs?[/quote]
Thats what i thought, an AC30 is deafening and so is the fender even at 25w. Maybe bass is different but i would of thought 50w would be good.

The ashdown cab was 8 ohm and i v'e got a choice of 7.5 or 15 ohm outputs. i used th 7.5 ohm.

I know i cant compete with the fender but hes got to turn down anyway so that we can hear the drums for a start and we have an audience left standing.

[Adrenochrome]

[quote name='bass_ferret' post='275045' date='Sep 1 2008, 10:51 PM']Valves sound louder cos they induce compression - which is why lots of compressors have valves in.[/quote]
Yes, I know, I was trying to avoid misleading the poster further with the notion that valves are much louder than SS and that it must therefore be the cab that's at fault.

[obbm]

[quote name='bennifer' post='275010' date='Sep 1 2008, 10:16 PM']and at what impedance does the head kick out 50 valve watts at?[/quote]

It's a valve amp so that point is irrrelevant. You will get max output from a valve amp at any impedance as long as the output transformer tap is set to the same as the speaker.

Edited September 2, 2008 by obbm

[joegarcia]

Personally I'd save for something like a 4x12 or 2x15. Marshall VBC412's come up now and then for around £150. I'd avoid the Laney 4x10, as all the old Laney 4x10's I've heard have been awful and most of them broken.
If you aren't after a hifi clean tone then you'll be fine as long as you have enough drivers/air.

My Marshall JCM800 100w Bass series head through my Aguilar GS412 is very very loud indeed. The Aguilar has very good sensitivity though.

[joegarcia]

Don't think you're likely to get better then this for this sort of money:
[url="http://cgi.ebay.co.uk/Hartke-4-5-XL-bass-cabinet-400-Watts_W0QQitemZ180283625917QQcmdZViewItem?hash=item180283625917&_trkparms=72%3A984%7C39%3A1%7C66%3A2%7C65%3A12%7C240%3A1318&_trksid=p3286.c0.m14"]http://cgi.ebay.co.uk/Hartke-4-5-XL-bass-c...id=p3286.c0.m14[/url]

[BigAlonBass]

"Back in the day" I used one of these, and the only thing that would cope with the output was a 4x12" 200 watt cab. A friend in a local Band STILL uses a 100 watt example, and it drives two 4x12" cabs up to rather astounding volumes with no farty noises whatsoever.





(Edit for stupid spelling mistakes)

Edited September 2, 2008 by BigAlonBass

[The Funk]

[quote name='tom skool' post='274979' date='Sep 1 2008, 09:41 PM']yeah perhaps but i hadnt even got halfway.[/quote]

You do realise that "halfway" doesn't mean anything? You can get to full power long before halfway.

Is there an Input/Gain control and a Master/Volume/Output control? If there are two controls, then the first one controls the preamp (matching the output of your bass to the amp - you can get preamp overdrive with this), while the second one controls the power amp (matching the output from the amp to the speakers - you can get power amp distortion or damage your speakers with this).

50W is not a lot for a bass amp these days which means you'd have to use more speakers to move a lot of air and get more overall volume. Try an 8 ohm 4 x 10" cab with good sensitivity.

Edited September 2, 2008 by The Funk

[alexclaber]

Ignore all the posts that mention power ratings on cabs, they are totally irrelevant in this case. Your problem is a lack of amp power causing the amp to fart out, not the cab! The solution to this is a high sensitivity cabinet and the easiest way to get this is lots of speakers in a large box. If you have to use this amp I'd be looking at 8x10", 4x12" or 2x15" cabs to get enough sensitivity. Alternatively a DIY horn loaded box like a DR250 or OmniTop212 could do a good job with less size but you'll have to compromise on bass extension.

When people talk about "driving lots of cabs" like the amp is a truck pulling lots of trailers (cabs), they're completely misunderstanding how this all works. A better analogy is that the amp is like a burner and the cabs are like hot air balloons, and then the loudness you need is the weight of the basket and passengers. Add more balloons or bigger balloons and that burner can lift more weight.

Alex

[The Funk]

[quote name='tom skool' post='275049' date='Sep 1 2008, 10:55 PM']i v'e got a choice of 7.5 or 15 ohm outputs. i used th 7.5 ohm.[/quote]

[quote name='alexclaber' post='275299' date='Sep 2 2008, 11:24 AM']If you have to use this amp I'd be looking at 8x10", 4x12" or 2x15" cabs to get enough sensitivity. Alternatively a DIY horn loaded box like a DR250 or OmniTop212 could do a good job with less size but you'll have to compromise on bass extension.[/quote]

Can you get commercially available 8x10", 4x12" or 2x15" cabs with an impedence of 8 ohms? If not, the DIY BFM cabs might be the way to go.

Edited September 2, 2008 by The Funk

[Adrenochrome]

[quote name='alexclaber' post='275299' date='Sep 2 2008, 11:24 AM']Ignore all the posts that mention power ratings on cabs, they are totally irrelevant in this case. Your problem is a lack of amp power causing the amp to fart out, not the cab! The solution to this is a high sensitivity cabinet and the easiest way to get this is lots of speakers in a large box. If you have to use this amp I'd be looking at 8x10", 4x12" or 2x15" cabs to get enough sensitivity. Alex[/quote]

Hurray for some sense!
I used to have an HH 4x12 cab that sounded righteous with a 100watt amp driving it [SS or tube]. I only sold it because it wouldn't fit properly in the next car I got.

Edited September 2, 2008 by Adrenochrome

[alexclaber]

[quote name='The Funk' post='275304' date='Sep 2 2008, 11:28 AM']Can you get commercially available 8x10", 4x12" or 2x15" cabs with an impedence of 8 ohms? If not, the DIY BFM cabs might be the way to go.[/quote]

You can rewire most 4 ohm cabs to 16 ohms which would do the job.

Alex

[The Funk]

[quote name='alexclaber' post='275316' date='Sep 2 2008, 11:42 AM']You can rewire most 4 ohm cabs to 16 ohms which would do the job.[/quote]

And then he could just stick the amp on the 15 ohm setting.

[Balcro]

[quote name='tom skool' post='274961' date='Sep 1 2008, 09:25 PM']hi i'm new here!
Ive just got myself a 50 watt selmer treble'n'bass head but as its considerably louder than a 50 watt solid state i've got no idea what size cab i need for it.
I tried it out with 15inch 200 watt ashdown cab and that started to fart a bit before i reached half way with the volume. I do like a bit of distort which is why i went for the 50 watt and not the 100 watt but this wasnt particularly nice and i think it was more the speaker complaining. does that seem right?
I've seen a laney r410 thats within my budget which i think is 250 watt. would that extra 50 watt make the difference?
I play mostly pub gigs playing rock/ indie covers and i've managed for years with 150watt ashdown combo but our guitarist is not only deaf but has serious GAS and has ended up with a 100watt fender twin! Although it is switchable to 25watt (yeah right,hes gonna wanna do that!)
tom[/quote]


Hi Tom,

Good luck with the valve experience.

I'm suspicious that you're getting such horrible distortion at 50% on the volume knob. I could/would use mine about that level to start with and not expect any fart! Not even an overdrive sound. I wonder if it doesn't need servicing to check that you're getting the correct output.

Just checking - you did use the right-hand side output jack, didn't you? Have you tried both the Left & Right inputs on each channel? One may be a higher gain than the other.

In competion, a 15" Ashdown or any other 15 for that matter, is often a decibel or so less efficient than a 12" or a 10", so alex's and billfitzmaurices' posts make sense to me. I used to use mine for an ELKA home organ and an inefficient 1x18". Fine for practice sessions with small combo's and I never heard even nice distortion. At home in the front-room I could make the house shake. However, put it up against a lead guitar through a 100w Marshall 4x12 stack and it got drowned out.

Balcro

[OldGit]

I'd start with a service and maybe a new set of valves ...