OMW to get my rig.. Some doubts about it.

[droo46]

Not sure that's as much of an amp thing as speaker. If its the PF-115HE, I vastly prefer just about anyone's 10's.

Even comparing the DI signals from both amps I prefer the Rocket.

 

[agedhorse]

Even comparing the DI signals from both amps I prefer the Rocket.

Personal preferences versus which is better. Either could be good choices.

 

[abarson]

I get what you mean. The reason I am rushing is because I live in the US now, but un less than 20 days I go back to my country ( South America ). There, any amp is twice as expensive ir more. You can pay 2 thousand for a aguilar 350 that here is about $600 . So I want to take one amp with me, and then get a cab ( which will be expensive but I got no option, I can't bring a cab in the plane, or I could but not in this trip).

Be aware as to the AC voltage for powering the amp. Most of the class D amps have universal power, but you need to be certain. Some make voltage selection as easy as a switch, while others require jumpers, change of fuse, etc.

 

[10emmanuel]

Be aware as to the AC voltage for powering the amp. Most of the class D amps have universal power, but you need to be certain. Some make voltage selection as easy as a switch, while others require jumpers, change of fuse, etc.

good info

 

[10emmanuel]

2 of the 3 amps the OP cited had two speaker outputs. Not really relevant outside the TC one he cited, which is the context of what you quoted from me.

other amp that drew my attention was the peavey minimax v2 600 watts. It claims 600 RMS. and there a tons of great reviews here and in other sites.

 

[agedhorse]

What can you get serviced easily in your country?

Just note that the warranty that comes with a US purchase will probably not be valid outside of the US.

 

[10emmanuel]

What can you get serviced easily in your country?

Just note that the warranty that comes with a US purchase will probably not be valid outside of the US.

anything lol

 

[mikewalker]

Now that you mention you are looking for an amp to "fly home" i would tend to jump on the "buy the nicest amp your budget will allow bandwagon" (my choice would be a Mesa TT800)

BUT I'd definitely research your country's own musical instrument distribution network and try to find out what amps there are actually supported for warranty claims (or might even have solid repair networks out of warranty). I'm a big fan of Hartke gear (I own three of their cabs and two of their amps) and they have one of the biggest worldwide distribution networks for bass amps: Distributors | Hartke

 

[agedhorse]

anything lol

Are you sure about that?

 

[G-Dog]

I get what you mean. The reason I am rushing is because I live in the US now, but un less than 20 days I go back to my country ( South America ). There, any amp is twice as expensive ir more. You can pay 2 thousand for a aguilar 350 that here is about $600 . So I want to take one amp with me, and then get a cab ( which will be expensive but I got no option, I can't bring a cab in the plane, or I could but not in this trip).

Aha! So, you don't really want to buy a combo or any cab(s) right now because of travel plans! That narrows down the recommendations to just good amp heads. So ... ...

Get the Invalid Link Removed, either here in US at $750 or in South America at twice as much. It's worth it! 4 band EQ with 3 voicing buttons and built-in Overdrive. 400 watts continuous into a single 8 ohm 400w cab, or 800w into 4 ohms (two 8 ohms), 2.67 ohms (three 8 ohms, or one 8 ohm & one 4 ohm), or 2 ohms (four 8 ohms, two 8 ohms & one 4 ohms, or two 4 ohms)!! Stereo Aux input, headphones output and FX Loop. Two combo Neutrik 1/4"-or-Speakon cab connectors and a Pre- or Post- preamp XLR Out, with Ground Lift, unaffected by the Master volume control. All in a small 5.8 lb. box. You can't get more power and flexibility at that price anywhere!!!
.

 

[10emmanuel]

Aha! So, you don't really want to buy a combo or any cab(s) right now because of travel plans! That narrows down the recommendations to just good amp heads. So ... ...

Get the 7ender Rumble 800HD amp head, either here in US at $750 or in South America at twice as much. It's worth it! 4 band EQ with 3 voicing buttons and built-in Overdrive. 400 watts continuous into a single 8 ohm 400w cab, or 800w into 4 ohms (two 8 ohms), 2.67 ohms (three 8 ohms, or one 8 ohm & one 4 ohm), or 2 ohms (four 8 ohms, two 8 ohms & one 4 ohms, or two 4 ohms)!! Stereo Aux input, headphones output and FX Loop. Two combo Neutrik 1/4"-or-Speakon cab connectors and a Pre- or Post- preamp XLR Out, with Ground Lift, unaffected by the Master volume control. All in a small 5.8 lb. box. You can't get more power and flexibility at that price anywhere!!!
.

I've been looking on that actually. It cost twice as much as the PEAVEY MINIMAX V2 600. Yes I know Fender is one of the most reliables manufactures and yes It delivers more watts. Although those two are my main options right now.

 

[Phreaky Phriday]

My guess is if you dont fall in love with the amp you pick, you could easily sell it back home - if you are having a hard time deciding, you might want to look at what has the bigget price difference between home and the states.

 

[10emmanuel]

If you are so sure about this, why are you asking questions? Makes no sense, unless you are actually trolling the forum.

here is the thing. I am in the US right now. So I would buy here because there is huge variety and to half price, but then I go back to the third world.

 

[G-Dog]

I've been looking on that actually. It cost twice as much as the PEAVEY MINIMAX V2 600. Yes I know Fender is one of the most reliables manufactures and yes It delivers more watts. Although those two are my main options right now.

Rumble has more watts and the best cab flexibility, down to 2 ohm (four 8 ohms, two 8 ohms & one 4 ohms, or two 4 ohms), in its price class!
.

 

[Wasnex]

Hello mates!

I am extending a post that I made yesterday about the same topic ( see here if you wish Expensive HEAD affordable CABINET or expensive BIG COMBO? )

I have done some research in the past weeks and also talking advices from the mentioned post, I am aiming to some amps that have particular features I am interested on.

The amps I liked were:
TC electronic BQ500. I love the fact that YouTube is full of good reviews about this one.
Ampeg PF-500 portaflex, Ampeg is a well know brand. Little review on YouTube.
Hartke lx5500. Also little review on YouTube but I kind of trust it because hartke is also a big brand.

What do you guys think about these three?
I decided to buy new, that's why many other options I liked got out of the final list.

The features that they have are price and watts. (I don't want to dig into tone because that's another story)

Now, first thing I notice is that the great majority of cabs of less than 400 watts are 8 ohms. That means that with the mentioned amps on 8ohms they actually run about 150-200 watts. I found only 2 cabs 4ohms under 400 watts. 1 of them is 115, while the other is 210 ( I prefer 210 but that one is a Aguilar that cost $1.300).

In some guide I read, I found that " as a general rule, the amp should double the watts of the cab". That means that if the amp runs 150 watts at 8 ohms, my cab should be even smaller?

So what should I do if I want to have more options in cabs? As I said in the other post. I will play small gigs and garage band rehearsals mostly. Nothing big. But I wanna have a solid equipment to keep up with any drummer.

Should I look for a head with higher watts on 4ohms ( like 700 watts 4 ohms ) in order to be able to extend those cabs's watts on 8ohms?

Thanks everyone!!

@Plucky The Bassist
@abarson
@bherman

In general, if the amp is 4 ohms minimum, many people would choose an 8 ohm cab. This gives you the potential to build an expandable modular rig. Then, if you have a relatively quite gig, take one cab. Need to play louder, take both cabs.

If your amp makes the same power at 8 to 4 ohms, you get +3dB from adding the second (matching) cab.

If the amp doubles the power when you go from 8 to 4 ohms, you get +6dB from adding the matching cab.

Some amps make more power when the load is changed from 8 to 4 ohms, but they don't double the power. Under this circumstance you somewhere between +3dB and +6dB when you add a matching cab.

Now let's consider what happens when you trade an 8 ohm cab for a 4 ohm cab. The first thing to consider is can the cabs handle the full power of the amp. Some amps generate twice as much power at 4 ohms.

The second consideration is the sensitivity of the cabs. When companies make both 8 and 4 ohm variants of the same driver, it's not unusual for the 4 ohm version to be 1-2dB less efficient. Best case scenario is the amp makes twice as much power with the 4 ohm cab. Doubling the power is a +3dB change. However, if the 4 ohm cab is -2dB less efficient, you only net +1dB. 1dB is not generally consider statistically relevant, because it's hard reliably hear a 1dB change.

If the amp does not double the power, it's possible the 4 ohm cab will not play as loud as the 8 ohm cab.

My point...don't focus solely on power. The volume comes from useable power and the sensitivity of the speaker system you are using, so you need to consider both factors.

I don't recommend using an amp that is rated for twice as much power as the speaker. Speakers have different types of power ratings. The RMS power rating is essentially the thermal rating of the voice coil. In other words how much power the voice coil can handle long term without overheating. Program power is generally 2x the RMS rating. This is probably where the advice comes from. The advice is relatively safe for mid range frequencies but not frequencies below 100hz. Also, if the long term average power exceeds the RMS rating for two long, the voice coil will get burned.

In all honesty, the Program power rating is the max power the speaker is expected to be able to handle and survive. Some of the tests only require the driver to survive for about 2 hours, and the driver is not required to meet specs after the test. So for long term reliability, you probably don't want to slam a driver will it's full program rating.

Before I go further, when you are dealing with bass amp, you also need to be concerned with mechanical power handling, which is most relevant for frequencies below 100hz. Mechanical power handling is determined by how far the woofer can safely vibrate without being damaged. The amount the driver moves is determined by how the cab is tuned. My point is if you put the same driver in different cab designs, the mechanical power handling will vary from one cab design to the next.

It's not unusual for the mechanical power handling to be significantly lower than the driver's RMS rating. In other words you can damage the drive with less than the RMS rating. Using an amp that can produce 2X the speaker's RMS power rating makes the risk of damage much more likely.

AFAIK, the reason for RMS, Program, and Peak power ratings is because speakers are rated with a 6db crest factor. Crest factor is the ratio between the peak value of a waveform and the RMS value. So many companies will post a RMS power rating (long term average in RMS Watts), Program Power (short term average in RMS Watts and 2X the RMS rating), and Peak Power (instantaneous power in Peak Watts).

You might see something like Power Rating: 200W RMS, 400W Program, 800W Peak.

The tricky part is the relationship between the Peak rating and the RMS and Program ratings. Peak power is measured in peak volts and peak Watts. RMS and Program power are measure in RMS volts and RMS Watts.

Notice the peak power rating appears to be 4x the RMS rating and 2x the Program rating. But if you do the math, the Peak power is exactly the same amount of power as Program power.

Here is our Power Rating: 200W RMS, 400W Program (RMS), 800W Peak.

Let's convert the Peak value to the equivalent RMS value.

We need to know the impedance to determine power. So assume these rating are at 4 ohms. Let's find the peak Voltage rating for 800Wp at 4 ohms.

Voltage = sq rt(power x impedance)
Voltage = sq rt (800 x 4) = ~56.57Vp.
​

Now we will convert this to the RMS voltage value.

~56.57Vp/(sq rt of 2) = 40V RMS
​

The salient point I want you to see is 40V RMS = ~56.57Vp...it's the same value using different measurement units.

Now we determine how much power is dissipated at 4 ohms with 40V RMS applied.

Power = (Volts^2)/Impedance
Power = (40^2)/4 = 400W RMS
​

This shows that 400W RMS is the same as 800Wp
400W RMS = 800Wp

Remember I mentioned a 6dB crest factor is used to test speakers.

- 200W RMS to 400W Program RMS is 3dB
- 400W Program RMS to 800Wp is 3dB.
- So the RMS to Peak crest factor 3 + 3 = 6dB.

But the 3dB difference from Program to Peak power is really a conversion of measurement units rather than an actual change.

Hopefully this will make it a bit more clear.

A pure sine wave has a 3dB crest factor.

The RMS voltage is ~0.707V and the peak voltage is 1V

RMS Watts at ~0.707V RMS and 4 ohms.
(~0.707^2) x 4 = 2W

Peak Watts at 1Vp and 4 ohms
(1^2) x 4 = 4Wp

So if you measure the RMS value, you get the blue line and if you measure the peak value you the red line.

The waveform does not change only the units of measure.

- So 2W RMS to 4Wp is a 3 dB crest factor
- However, 2W RMS = 4Wp
Yes it blows my mind too.

My advice. Disregard the Program rating and Peak rating. An amp rated for about the same as the speaker's RMS rating is relatively safe...but you still may have enough power to destroy the drivers if you push the rig hard enough.

In other words if you get an amp rated for 400W RMS, you need a speaker rated for at least 400W RMS.

You can certainly use an 800W RMS amp with a 400W RMS speaker...but you have to use more discretion and restraint. Often speakers sound great right up to the point where the go silent. Meaning you can't always tell you are pushing a speaker too hard.

​

 

[wysiwyg248]

I don't own any of these amps, but used the TC electronics at a Latin club in Toronto (very loud environment) and everything was fine.
If you are flying back to South America, I recommend getting a heavy duty spike protector for your amp.
Have a safe trip!

 

[lokikallas]

My choice would be the pf500. I’m in camp “no such thing as under powering” so I always like to have a cab that matches or exceeds the amps output rms rating.

 

[Killing Floor]

Watt is not a unit of bass amp volume. Neither is Ohm.

Use decibels. That will give you a better indication of how loud a bass rig is.

 

[Aidenn7]

whatever you get the only cab you want at 4ohms is a 810.. 15 or 410 should be 8ohm.. thought I'd give you a good rule for noobs

 

[DaveParker39]

Of the options, the Hartke is my fave.
I gigged one for a long time and then got my 28lb Fender Rumble 800 and never looked back.