Speaker Selection help!

Quattroste

I have a lovely solid wood Mongotone Cab that is 2 x 10. The original speakers were Jensen P10R's but they seem to be blown/dead. So I want a replacement set. My thinking at the moment is a set of Celestion Greenbacks (30watts). The amp powering these is a Matamp First Lady (7 watt). I would however, like to be able to use other amp heads (I'm considering a Marshall head) but if I go over a 30 watt amp I risk blowing the speakers right?

What other reccomendations would you guys have for 10" speakers that are good quality and versatile and will allow higher watt amps to be used?

punchdrunk

i'd definitely give webber speakers a look
supposed to be the dogs whatsits

Voodu Child

Quattroste wrote: »

The amp powering these is a Matamp First Lady (7 watt). I would however, like to be able to use other amp heads (I'm considering a Marshall head) but if I go over a 30 watt amp I risk blowing the speakers right?

Well, its a 2x10 cab so if you went with 30 watt speakers you'd have 60watts rating. So a 50watt head would be fine, but not a 100watt.

Paolo_M

@ 2 X 10 your cab would have a power rating of 60 Watts if you use the greenbacks.
A 50 Watt Marshall at full tilt would still blow it into the great blue yonder.
The V30 is rated at 60 Watts. Two of these would handle most >= 50 Watt amps. You'll stuggle to get a 2 X 12 to handle the might of a 100 Watt head at full tilt.
The V30 speaker is "punchier" than the greenback so you might find it "harder" sounding than the greenback if that's the tone you were hoping for.
If your happy to stay below 60 Watt cab rating (let's face it; who runs a 50 Watt flat out anyway? :eek:) then why not try a mix of speakers, greenback for warmth, V30 for punch? Once the impedance of the speakers is matched the power will distribute evenly between them. Remeber though that you limit is 60 Watts and not 90 like you might expect. The V30 could handle it but the poor old greenback would burn up.
I've also heard great things about the weber speakers, though I don't know much about them.

Alanstrainor

I've got two Ted Weber Speakeres myself, and i have to say they are awesome, really great, i'm pretty sure they're both ceramic, one 6" and one 12" can't remember what wattage they are off hand. But they really are great. Bought them on ebay from a seller called vintagemusic4u or something similar, and both arrived quickly. Didn't buy off Teb Weber directly as he seemed reluctant to give me a delivery quote before placing an order, which seemed ridiculous tbh. But, in short, i'd recommend them!

Voodu Child

Modern speakers, especially Celestions, are very conservatively rated (by as much as 50%). They have to be, or they'd have tonnes of returns and be breaking consumer law.

A 60 watt cab (2x30 watt speakers) will handle a 50 watt amp at full tilt no problem. Marshall ship 50watt combos with 2x25watt greenbacks for example. Ditto for 100watt amps shipping with 2x60 watt speakers.

Quattroste

Seriously lads thanks for the info. This is why I love this site. Firstly I'll investigate the Webber's but if all else fails I'll go for the the V30 and the Greenback. I'd be unlikely to have a Marshall full blast anyway

Paolo_M

voodoo_child wrote: »

Modern speakers, especially Celestions, are very conservatively rated (by as much as 50%).

I knew they had a built in margin but didn't realise it was 50%. Thanks for the info.
In that case it would cover a 50 Watter with about 15 Watts to spare.

Voodu Child

Paolo_M wrote: »

I knew they had a built in margin but didn't realise it was 50%. Thanks for the info.
In that case it would cover a 50 Watter with about 15 Watts to spare.

Its such a muddy issue. As you know, a '50 watt' amp (valve) can/will put out plenty more than 50watt at the speaker. And one 50watt amp could put out way more than another...there's no real standard, '50 watt' is just a convenient label that manufacturers tend to put on any amp with 2xEL34 (or whatever) :pac:

These days, speaker manufacturers just way over-rate their speakers and slap on a label of 30watts or 60 watts or whatever so they'll know the speaker will be happy with the 'equivalent' rated amp. Its just a rough way of rating things which is why the margin can be so big. Basically stick with a cab that is rated right and you should be fine, the layman shouldn't need to worry about fos, thats the manufacturers job.

Quattroste

One more question. If 2 16ohm speakers gives the cab an overall rating of 8ohm then 2 8ohm speakers give the cab a rating of 4ohm right? My amp can handle both.

Does this make any difference to the overall tone however?

Voodu Child

Quattroste wrote: »

One more question. If 2 16ohm speakers gives the cab an overall rating of 8ohm then 2 8ohm speakers give the cab a rating of 4ohm right? My amp can handle both.

Does this make any difference to the overall tone however?

It depends on whether you wire them in series or parallel.
2x8ohm [parallel] = 4ohm
2x8ohm [series] = 16ohm

Quattroste

Voodoo. I'm not changing the wiring and originally it was classed as 8ohm with 2 16ohm speakers so I guess parallel.

Does the tone change if its 4 or 8ohm?

Paolo_M

Quattroste wrote: »

Voodoo. I'm not changing the wiring and originally it was classed as 8ohm with 2 16ohm speakers so I guess parallel.

Does the tone change if its 4 or 8ohm?

I've seen debated verbatum on-line.
There will be no difference in tone produced by the amp itself if the impedances are matched, fact.
Mis-matched impedances will cause a slight shift in the amp bandwidth, this is nothing that tweaking the EQ wouldn't even out. We all know mis-matching is'nt a great idea too, right.

People do swear there is a difference in tone between 4 and 16 ohms with amp and cab matched accordingly. I've tried both and couldn't really hear any difference, again certainly nothing that a slight tweak of the treb wouldn't level out. Yet people swear there's a difference.

My theory (I can find nothing to support it!!:pac:) is that a certain level of mutual inductance might occur in a cab. In parallel this mtual inductance would tend to reduce the Henry value whereas in series it would add thus increasing the Henry value. If this is occuring then a 4 X 12 might have a slightly higher resonant peak @ 16ohm (series parallel) than @ 4 ohm (parallel). Again this is just me thinking out loud and I could find nothing on-line to support it. I can think of no other reason why there might be a difference.

Voodoo, Eoin any idea's?

Quattroste

Thats good enough for me, thanks all.

Eoin Madsen

Without adjusting the amp output impedence there should definitely be some kind of difference in sound between using the correctly matched value and the mismatched one. If you're changing an amp setting so that it's matched in either case, it gets into the aforementioned hazy area.

Voodoo, Eoin any idea's?

Well, the 16 ohm tap on the OT will use the entire secondary winding, vs the other taps which use progressively less of the winding. I don't have much idea what difference this makes electrically, but I understand there is some - there are pros and cons to how much wire you use in a coil, irrespective of the ratio. Internal capacitance, inductance, resistance etc. I guess the question is whether it falls into the realms of audibility or not. If it does, I would bet that it's more noticable at higher wattage.

I've never bothered to test. :pac: