Enjoy the benefits of a premium membership!
Upgrade Account
-
TalkBass has been independent since 1998. Add your voice.
Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
Join free Log in
Want zero display ads or expanded classifieds tools? Compare plans.
Double Bass Can guitar amp heads use a bass cab?
- Thread starter bushy
- Start date
Sure. Same rules as any other head/cab combination. If SS head be sure min impedance spec is equal to or lower than cab spec. If tube, this rule is inverted.
The amp spec determines what cab it is compatible with or it's the other way around?
Amp spec. The amp is what would suffer damage with a bad match. For example don't run a SS amp with an 8ohm minimum spec into a 4ohm cab. And don't run a tube amp with an 8ohm maximum spec into a 16ohm cab.
The Quilter 101 mini head is 50-100 watts I think and can go into 4 and or 8 ohm cabs. Can it work with the GK Neo 212 since it's 8 ohm? Although this cab it's higher wattage, I guess that's fine?
assuming you saw but the quilter 101 is on sale at musicians friend for their stupid deal of the day. better snap it up quick!
Not exactly.
Tube amps want to see the correct impedance. So if the amp is rated for 4 ohms it will make max power and be safe to run with a 4 ohm load. If you connect a 2 ohm or 8 ohm load, this results in an impedance mismatch and the amp will make less power, experience increased tube wear, and possibly have a major melt down if it can't cope with the mismatch.
Tube amps are safer into a dead short (0 ohms) than and open circuit (infinite ohms). But it varies by how the amp is designed whether it is safer to run a 2:1 or 1:2 impedance mismatch. Some amps handle both, some amps handle one but not the other, and some amps should not be run with an impedance mismatch.
The best rule is the connect the amp to the expected load. If for some reason, you need to run an impedance mismatch, the best advice is to consult your owners manual, tech support for the company who made them amp, or someone who has technical expertise on the amp.
Luckily, many amps have multiple output taps. I have amps with taps for 2, 4, and 8 ohms, and also amps with taps for 4, 8, and 16 ohms. One of my amps even has some complicated switching jacks that connect the speakers in either series or parallel, depending upon which jacks are used.
I understand all that. I was speaking generally. It's usually safe (but not ideal) to go below spec'd impedance with a tuber. But never above.
Again, not exactly.
Mesa specs a "safe mismatch" as running a load that is one order higher than the amp expects.
See attached, scroll to the 2nd page (numbered 32), and look at figures 3 and 5.
This is how Mesa defines a "safe mismatch" with all of their tube amps that I have ever researched.
Mesa is not the only company that does this, so the best advice is read the manual or contact an expert instead of relying on a general rule that may be wrong.
Last edited:
As far as using a Quilter 101 for a bass amp, it's not going to be a problem for the amp or speaker.
If you already have the amp, try it. Reasonable questions are: will it sound good, and will it get loud enough? IMHO, only you can answer these questions.
Limiting Factors
Some guitar amps have high pass filtering that may limit the low end more than you like, and the tone control center frequencies are chosen for guitar rather than bass. Also, I believe the 101 preamp is designed to produce over drive, so keep the gain setting below 3. Power is listed as 50W at 4-8 ohms max, which is not a lot.
If you already have the amp, try it. Reasonable questions are: will it sound good, and will it get loud enough? IMHO, only you can answer these questions.
Limiting Factors
Some guitar amps have high pass filtering that may limit the low end more than you like, and the tone control center frequencies are chosen for guitar rather than bass. Also, I believe the 101 preamp is designed to produce over drive, so keep the gain setting below 3. Power is listed as 50W at 4-8 ohms max, which is not a lot.
Not sure why Quilter mentioned it can fill up a house, I guess with a pair of the blockdock cabs from Quilter? I'll try to get a real cab for it so I can drive it...
50W is a lot of power for guitar...not so much for bass.
The sensitivity for the GK Series II Neo 212 is listed as 101dB which is very respectable. It's an 8 ohm cab and it's not 100% clear if the Quilter 101 makes the same power in both 4 and 8 ohms.
I see that makes sense. I also read somewhere that smaller speakers have more character for guitars. I've tried amp sim using small as the option and it's true. I'm looking at the ZT lunchbox cab which has a 6.5" speaker. Any other suggestions? I think Seismic has a 6" x 4:
Rift 46G - 4x6 Bass / Guitar Speaker Cabinet
Rift 46G - 4x6 Bass / Guitar Speaker Cabinet
Last edited:
I believe the most common guitar speakers are 12s followed by 10s. I have one 212 and five 412 cabs; I also have a combo with a single 10. IMHO, you also see a few 15s and fewer 8s.
It really depends upon what you want to do. You probably don't want to hit most 6.5" or smaller speaker with 50W even if you playing guitar, and you especially don't want to hit such a small speaker with 50W of bass. Yes there are small driver bass cabs like Phil Jones. I have played the PJ Bass Briefcase which is 100W into two 5s, and it sounds nice, but it is not very loud or capable of producing anything approaching deep bass. The sensitivity of the internal speakers is listed as 92dB/W/M
The GK 212Neo is a decent bass cab. I don't think it will be ideal for guitar, but it might sound okay. If you plan to use distortion you will probably want to dial the tweeter to 0.
IMHO, when possible, the best advice is always try before you buy.
Well for guitars anyway, you don't think the ZT lunchbox cab with 6.5" speakers (8 ohm, 100 watts), is capable on stage? Maybe a pair of these? It's $149 each. How about the Seismic 5x4 (8 ohm, 250 watts), which is sold as for guitar and bass cab? It's $179. I haven't checked the specs yet.
Only you can decide if these products meet your needs. The sensitivity rating on the Seismic is 92dB so it's not going to get very loud with 50W. Fine for practice, but I would consider it unusable for performance. FYI, Seismic is a low end product line. The cab is rated for 250W RMS/500W peak, but I suspect that is extremely optimistic.
I don't see any specs for the Lunchbox cab. Probably good for practice or projects. I wouldn't run bass through it at any significant level. Be advised the manufacturer lists this product as discontinued, though dealers may have stock, so if you are interested, you probably need to act quickly.
There is no problem with buying inexpensive products as long as they serve you well. But if they delay or prevent you from buying a more expensive product that you need, IMHO it's often better to save your money until you can get the right tool. You have to decide which path to take.
For context. The 10" speaker in my 12W combo guitar amp is a Celestion G10 Gold. These run $175 USD new just for the driver, but it's a high end driver. The combo is an early 60s Fender Princeton, and the original Oxford was having problems, so I replaced it with a lightly used G10 that I got for $115.
The G10 is rated for 40W and has a sensitivity of 98dB. It will take more power and play considerably louder than the original speaker, and also is a bit brighter, which is something I wanted, since the Princeton has one tone control and is sort of dark. The research I did suggests the amp is giggable with the G10, and more suited as a practice/project amp with the original Oxford. If the Oxford was not failing I would not have replaced it, but I think the G10 is better in pretty much every way.
By taking my time, doing some research, and buying used, I got a better speaker that was practically new.
