Using combo speaker as extension speaker

[yituool]

Hi, I've got a Trace Elliot GP7SM130 bass combo, it's awesome, but It's only rated as 130 watts into 8ohms, and only has one 10 inch speaker, so in order to get more power out of the amp I'd need another speaker.

Well, being the skint tightwad that I am, instead of forking out for another cab for now, I thought about using the 8" speaker in my Marshall MB15 combo for a littlle extra oomph, connecting the extra speaker output on the Trace Elliot, into the Marshall's line in, which I believe just sends a signal straight to the combo's speaker. But I'm not the best mind when it comes to impedance and all that, so I thought I'd come to you guys first before breaking anything. Is this feasible? In the Marshall's manual it says its power output is 15w into 4ohms, so does this mean I should not connect it to the Trace Elliot's 8ohm output?

Any help would be much appreciated, cheers

[Mr. Foxen]

Need to figure what the speaker in the MArshall is rated at. If they are both 8 ohm, then you could run both. Probably not worth bother with though. One will probably fart out earlier than is helpful. The speakers are much more of a limiting factor that the amp power. 130w is quite a lot.

[ColinB]

A 'line in' connection usually connects to the amps power stage, missing out the pre-amp, not directly to the speaker.

[The Funk]

[quote name='ColinB' post='656661' date='Nov 17 2009, 08:42 AM']A 'line in' connection usually connects to the amps power stage, missing out the pre-amp, not directly to the speaker.[/quote]

Indeed

[yituool]

[quote name='Mr. Foxen' post='656451' date='Nov 16 2009, 09:38 PM']Need to figure what the speaker in the MArshall is rated at. If they are both 8 ohm, then you could run both. Probably not worth bother with though. One will probably fart out earlier than is helpful. The speakers are much more of a limiting factor that the amp power. 130w is quite a lot.[/quote]

The manual says it's 15w at 4ohm, I'm not completely sure whether that sure whether that means it would be 4ohm when connecting another amp.



[quote name='ColinB' post='656661' date='Nov 17 2009, 08:42 AM']A 'line in' connection usually connects to the amps power stage, missing out the pre-amp, not directly to the speaker.[/quote]

Does that mean that this should not be attempted?

[Beedster]

[quote name='yituool' post='657507' date='Nov 17 2009, 09:31 PM']The manual says it's 15w at 4ohm[/quote]

Then don't do it !

[maxrossell]

[quote name='yituool' post='657507' date='Nov 17 2009, 09:31 PM']The manual says it's 15w at 4ohm, I'm not completely sure whether that sure whether that means it would be 4ohm when connecting another amp.

Does that mean that this should not be attempted?[/quote]

Unless the speaker has a 1/4" jack that can literally be unplugged from the combo's head (which I don't think is the case on the little Marshall practice jobs) then you can't run your other amp through it.

You can't run a speaker output into a line-in. Best case is you won't get any sound, worst case is you'll blow a transformer in your Trace, and possibly the Marshall's power section.

You either need a bigger amp, or an actual extension speaker.

[yituool]

[quote name='maxrossell' post='657528' date='Nov 17 2009, 09:56 PM']Unless the speaker has a 1/4" jack that can literally be unplugged from the combo's head (which I don't think is the case on the little Marshall practice jobs) then you can't run your other amp through it.

You can't run a speaker output into a line-in. Best case is you won't get any sound, worst case is you'll blow a transformer in your Trace, and possibly the Marshall's power section.

You either need a bigger amp, or an actual extension speaker.[/quote]

I tried it throuhg the amps line-out and got sound.

I don't think I need a bigger amp, I just need more than a 10" speaker to get more power out of the amp

[maxrossell]

[quote name='yituool' post='657533' date='Nov 17 2009, 09:58 PM']I tried it throuhg the amps line-out and got sound.

I don't think I need a bigger amp, I just need more than a 10" speaker to get more power out of the amp [/quote]

If you take a line out from the Trace then you can run it into the Marshall no problem.

It's from the ext. cabinet output that you'll have trouble.

[yituool]

[quote name='maxrossell' post='657571' date='Nov 17 2009, 10:33 PM']If you take a line out from the Trace then you can run it into the Marshall no problem.

It's from the ext. cabinet output that you'll have trouble.[/quote]

Yeah, but how much quieter would it be when run from the line-out?

[pete.young]

[quote name='maxrossell' post='657571' date='Nov 17 2009, 10:33 PM']If you take a line out from the Trace then you can run it into the Marshall no problem.

It's from the ext. cabinet output that you'll have trouble.[/quote]

And if you took a line output from a 130W amp and ran it into a 15W amp, I'd be amazed if it made enough difference in volume to compensate for how stupid it would look. This has to be a wind-up, surely?

[yituool]

[quote name='pete.young' post='658647' date='Nov 18 2009, 10:15 PM']And if you took a line output from a 130W amp and ran it into a 15W amp, I'd be amazed if it made enough difference in volume to compensate for how stupid it would look. This has to be a wind-up, surely?[/quote]

Didn't want to run it into the amp, just the speaker

Edited November 19, 2009 by yituool

[maxrossell]

[quote name='yituool' post='658554' date='Nov 18 2009, 08:59 PM']Yeah, but how much quieter would it be when run from the line-out?[/quote]

I've just checked out the specs of the MB15. The speaker is hardwired into the head and there isn't a line-in jack, so your only option if you want to use the MB15's speaker is to plug straight into the amp's instrument input and use the MB15 as a whole second amp.

The thing is that you can't plug a speaker output into an instrument input. You'll blow one or both of the amps. It's not an issue of quiet, you just can't do it. And even if you could find a way to bypass the amp head and only use the MB15's speaker (you'd have to cut the speaker wires and attach a 1/4" jack to them), it's not the correct impedance to match your Trace so you wouldn't be able to use it anyway.

Basically, what I'm saying here is your ONLY option to run the MB15 as an extension for the Trace is to run the line out from the Trace into the MB15's instrument input. I don't know if there's much point to that, really, you wouldn't get any more volume out of the setup, although I suppose you could use the MB15 as a monitor or something.

I'm afraid that your Marshall practice combo isn't going to be of any help in this matter. If you want more volume, you're going to have to invest in an extension speaker or get a bigger amp. Although to be honest I'm not even sure that getting another speaker is going to help with only 130w. If volume is your issue, if I were you I'd be looking into getting something more powerful.

[yituool]

[quote name='maxrossell' post='658665' date='Nov 18 2009, 10:27 PM']I'm afraid that your Marshall practice combo isn't going to be of any help in this matter. If you want more volume, you're going to have to invest in an extension speaker or get a bigger amp. Although to be honest I'm not even sure that getting another speaker is going to help with only 130w. If volume is your issue, if I were you I'd be looking into getting something more powerful.[/quote]

Apparently Trace Elliots like mine are rated extremely low for some reason, so 130 watts of Trace sounds more like 250-300W if it was rated by anyone else. I just wondered how true this was, and see how much power I could squeeze out of the amp. And apparently if I did get another speaker cabinet it would need to be like a single 10-12" speaker, which I can't find anywhere cheaper, or else the speakers would be imbalanced or something like that. I haven't been playing that long, so I have a very limited knowledge when it comes to this stuff.

Thanks very much for your advice though

[Moos3h]

Given the price that old skool cabs are going for these days, you could consider selling the Trace (you'd get a decent price for it as people value Trace stuff) and picking up a cheap head and cab. Peavey Black Widow-equipped 15's come up all the time and are dirt cheap but capable of taking a total beating.

Cheers,
James

[yituool]

[quote name='Moos3h' post='659435' date='Nov 19 2009, 05:11 PM']Given the price that old skool cabs are going for these days, you could consider selling the Trace (you'd get a decent price for it as people value Trace stuff) and picking up a cheap head and cab. Peavey Black Widow-equipped 15's come up all the time and are dirt cheap but capable of taking a total beating.

Cheers,
James[/quote]

But I love the Trace too

[LawrenceH]

[quote name='yituool' post='659437' date='Nov 19 2009, 05:12 PM']But I love the Trace too [/quote]

If you don't mind the weight your best option would probably be a second Trace cab, there's always some TE floating around secondhand. A speaker in a 15W combo is not going to be able to handle anywhere near the 100W output your TE would put into it - you'd destroy it.

[maxrossell]

[quote name='yituool' post='659428' date='Nov 19 2009, 05:04 PM']Apparently Trace Elliots like mine are rated extremely low for some reason, so 130 watts of Trace sounds more like 250-300W if it was rated by anyone else. I just wondered how true this was, and see how much power I could squeeze out of the amp. And apparently if I did get another speaker cabinet it would need to be like a single 10-12" speaker, which I can't find anywhere cheaper, or else the speakers would be imbalanced or something like that. I haven't been playing that long, so I have a very limited knowledge when it comes to this stuff.

Thanks very much for your advice though [/quote]

No worries. I would say that if you want to get the full beans out of your Trace head then you're gonna need a suitable ext. cab for that. As Moos3h suggested 15" Black Widows are cheap-as and come up all the time. I wouldn't worry too much about speaker imbalance as long as you leave a little spread between the amp and the cab. It's a compromise but it'll be worth it if you're looking for extra volume. And you'll "feel" a 15" cab more than a 10".

[Count Bassy]

I think its been made clear by others, but just to say it again - do not plug the speaker output of any amp into the line in of another.

To get 130w at 8 ohms your Trace must be pushing about 33 volts RMS, about 45 volts peak, into the speaker.
A line-in input is typically rated at 1 to 2 volts.
i.e. you will almost certainly damage something.

Use line-out to line-in and you will be fine - this is what line level signals are designed for!