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Ohms FAQ

#983
Jonathan T said:
[Invalid or Expired Link Removed]

This is what we use daily . Extremely durable , single use .
No affiliation .
Best,
Jonathan
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I haven’t seen one of those in the flesh in years (or decades).

Just note that it measures impedance at a single frequency (1kHz) which will generally but not always be close to the nominal impedance. For subwoofers, it may read as much as 2x high because of the inductance of that type of driver.
 
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#984
agedhorse said:
I haven’t seen one of those in the flesh in years (or decades).

Just note that it measures impedance at a single frequency (1kHz) which will generally but not always be close to the nominal impedance. For subwoofers, it may read as much as 2x high because of the inductance of that type of driver.
Click to expand...

We use others as well . I have never had any malfunctions when the simple TOA is used .
In the application re : single cab , bass or subs the nominal difference is not enough to damage an amplifier . Two questions , #1 What do you define as 'close' and #2 Can you give me a real world example , something I can repeat on my bench of 2x high ? Or any example thereof ?
I am not being a big head here . i regularly deal with many different combinations , some of the gear not mine . I really prefer not to blow stuff up....
Respectfully ,
JT
 
#987
Jonathan T said:
We use others as well . I have never had any malfunctions when the simple TOA is used .
In the application re : single cab , bass or subs the nominal difference is not enough to damage an amplifier . Two questions , #1 What do you define as 'close' and #2 Can you give me a real world example , something I can repeat on my bench of 2x high ? Or any example thereof ?
I am not being a big head here . i regularly deal with many different combinations , some of the gear not mine . I really prefer not to blow stuff up....
Respectfully ,
JT
Click to expand...
Here'[s an example, very common in 15 and 18" drivers with higher power and extended low frequency. I would call this a nominal 4 ohm speaker, at 1kHz the impedance is about 15 ohms:

upload_2021-4-13_19-4-35.png
 
#988
Hello friends, I have waded through several pages and even seen a post I put in here back in 2005! That same post referenced a Trace Elliot GP-12 Series 6 head that I was using up until this weekend, when it finally started making some decidely un-bass amp like sounds (think of a power steering squeal) during a gig.

I've been researching replacements/repairs when I realized that I have a free-to-me Carvin R600 combo not 5 feet away from me right now. I took the head from the cab and will be plugging in my 2 speakers (8ohm Ashdown 1x15 and 8ohm Avatar 2x10) to test in a little bit. The head, when played in its matching combo cabinet (2x8/1x15), sounds very midsy and does seem to have some speaker distortion (I think one is dying). I am very interested in trying with my other cabinets.

I think the 2 8ohm cabs will work fine with the head and in reading about bi-amping (which this amp is capable of), it seems it would be pointless, though potentially interesting to try. However, due to the mass amount of power ratings screened on the back of the amp, I am asking for verification and confirmation that my speakers will do the amp no harm, and vice versa.

Does this mean my 2 8ohm cabinets will be producing 175w per cabinet? Or do the 2 8ohm cabs become a total of 4ohm at 250w/cab?

20210802_182634.jpg
 
#989
You can safely run one cabinet per channel in dual mode, or both cabinets tighter in parallel in bridge mode.

I wouldn’t expect the difference to be all that significant in practice.
 
#990
agedhorse said:
You can safely run one cabinet per channel in dual mode, or both cabinets tighter in parallel in bridge mode.

I wouldn’t expect the difference to be all that significant in practice.
Click to expand...

I tried it out today and it worked and nothing blew up. Was surprised to have a power amp per cabinet, sort of cool to mess around with those settings.

The amp itself though does randomly crackle. Upon experimentation, the crackling seemed to lessen the higher I had the gain turned up and the louder I played. I think it would not be audible under a full band, but for dynamics, it might get annoying.

Only tried with my SB-2, no pedals or anything and the tone was super aggressive and heavy on the mids. Lots of string noise as well. I tried EQ-ing and messing with dials and really couldn't adjust it to my liking. I will try with my Tone Hammer DI, as well as another bass (L1K) to see about smoothing out the in-your-faceness of that sound.

As far as the crackling goes, may need some simple maintenance to get it to work properly.
 
#993
(please excuse me, because i have posted this question somewhere else, maybe in a wrong or too old place...)
__________________________________________________________________________________
Hello everybody,
i have read the original overpower/underpower thread, very very interesting but i am still confused because i am not a specialist, and a two years old bassist only:
i have a class AB amp boss Katana combo 210, 160 watts, 300 peak (say Boss).
I like this amp, i also have a rumble 100, but as a new bassist, i have learn with the katana what the word 'farting' means.
The katana is much more louder as the rumble.
The amp katana 210, a closed combo, has two speakers, 60 w each - 8 Ohm (Roland made in Malaysia).
(i dont understand how this can make 160 w but this is another question).
I would like to replace those 60 w speakers with two
Eminence Legend BP102-8.
those speakers are 200W RMS, 8 Ohm.
(i didnt found bass speakers with only 100w for example, maybe it would have been better).
Is this possible? i dont intend to play the amp at his max power, only sometimes as we play in outside bars i need a little more, but normally not.
Will the amp class AB 160w support these speakers, or not?
Thaks a lot ! and have a nice day
Philippe from France
 
#994
phipop said:
(please excuse me, because i have posted this question somewhere else, maybe in a wrong or too old place...)
__________________________________________________________________________________
Hello everybody,
i have read the original overpower/underpower thread, very very interesting but i am still confused because i am not a specialist, and a two years old bassist only:
i have a class AB amp boss Katana combo 210, 160 watts, 300 peak (say Boss).
I like this amp, i also have a rumble 100, but as a new bassist, i have learn with the katana what the word 'farting' means.
The katana is much more louder as the rumble.
The amp katana 210, a closed combo, has two speakers, 60 w each - 8 Ohm (Roland made in Malaysia).
(i dont understand how this can make 160 w but this is another question).
I would like to replace those 60 w speakers with two
Eminence Legend BP102-8.
those speakers are 200W RMS, 8 Ohm.
(i didnt found bass speakers with only 100w for example, maybe it would have been better).
Is this possible? i dont intend to play the amp at his max power, only sometimes as we play in outside bars i need a little more, but normally not.
Will the amp class AB 160w support these speakers, or not?
Thaks a lot ! and have a nice day
Philippe from France
Click to expand...
Read our answers on your other thread. Multiple threads asking the same question is not helpful.
 
#997
Just for disambiguity: Amp can mean either of two different things. It can refer to an Amplifier: and electronic device that increases loudness, or volume, or power of an electrical signal. The other use of Amp is a reference to the unit of electrical current, Ampere - literally the number of electrons, or units of charge, moving through a device or wire. Ampifiers are essential to hear music. Fuses and other electrical devices will be rated in Amperes.
 
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