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Most Useful Amp and Speaker Specifications?

Discussion in 'Amps and Cabs [BG]' started by agedhorse, Jul 20, 2019.


  1. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    I've been reading through some of the threads (which often seem to degenerate into pointless misunderstandings) about specifications and which ones are the most valuable or most important for the knowledgeable players, and how does this information help you?

    Generating detailed specifications takes a lot of time, a lot more than most folks realize. If the details have real value then it's worth the cost to acquire and tabulate/format the data but if it's not something that's useful, then it's nothing more than a waste of time and resources.

    I'm looking for your thoughts on this topic.

    It would be helpful to everybody for this thread not to deteriorate into a tube or solid state class AB versus class D debate, or a ceramic versus neo debate.
     
  2. Mr. Foxen

    Mr. Foxen Commercial User

    Jul 24, 2009
    Bristol, UK
    Amp tinkerer at Ampstack
    Nominal impedance.

    Sound stuff gets increasing subjecting over about 200hz

    Power handling is barely useful, because useful power output ratings aren't a thing in amps.
     
  3. H Nighttrain

    H Nighttrain

    Feb 12, 2018
    For cabs, most important spec to me is sensitivity, followed by freq response.

    It'd be great if every cab had a published freq response graph (instead of the usual -3dB points) so one could visualize how each cab rolls off on the high and low ends, and what freqencies are emphasized/deemphasized over its range.
     
    Dbass35, pigpen1, Microbass and 36 others like this.
  4. xaosbass

    xaosbass

    Feb 15, 2008
    I've been studying speaker design for years and the parameters stay the same no matter what the design is. I wanna see where this thread goes........
     
  5. Samatza

    Samatza

    Apr 15, 2019
    The parameters I would find useful are;
    Impedance
    Frequency response
    Sensitivity
    Power handling
    It still doesn’t tell you how it sounds but will allow you to at least match to an amplifier and other speakers.
     
    Bill Pool, Joebone and gitfiddl like this.
  6. xaosbass

    xaosbass

    Feb 15, 2008
    Win Isd does a good job and it's freeware. Eminence has links for their drivers that make since. AH, what are you looking for?
     
    John6 likes this.
  7. xaosbass

    xaosbass

    Feb 15, 2008
    High spl is good but means nothing to me w/o a response graph. Eminence and Partsexpress are really good at providing just that. I'm an electronics engineer btw, so these things mean something to me. I don't just build something all the while hoping it will work. The math works.
     
    BassikBrad likes this.
  8. el murdoque

    el murdoque

    Mar 10, 2013
    Germany
    For amps:
    Power Rating,
    Impedance,
    Measurements,
    Weight.


    For cabs:
    Impedance,
    Power Rating,
    Frequency Response
    Measurements,
    Weight.
     
    Border, BassManKK, bobyoung53 and 9 others like this.
  9. JimChjones

    JimChjones

    Aug 6, 2017
    SE England
    The caveat 'knowledgeable player' is interesting, because it seems to me just about everything except impedance really requires a significant degree of technical understanding.

    Am I right in thinking the question is about "what should we be publishing?" Its an interesting one, because I think its possible that one reason, maybe even the most important one, for publishing data is not so much to inform the prospective purchaser as to demonstrate to the purchaser that you are a serious company who does everything properly - an aspect of marketing and image really.

    Maybe an aspect of the question is "is there anything we can stop publishing without significantly affecting our image?"
     
  10. Mingo Sanders

    Mingo Sanders

    Mar 11, 2008
    Austin, TX
    First, I'll assume that you mean "speaker cabinet" when you ask about "speaker."

    For me it would be helpful to SEE the specs, especially power, in a demonstration. No, you can't do this in a 20-page paper owner's manual, but you can do it with some videos. Here's an example. In my opinion, one of the most widely held misconceptions is the concept of "matching" an amplifier to a speaker cabinet: "Will Brand A 600 watt amp work with Brand B 500 watt cabinet?"

    First, of course it will work, because the amp works across a range of zero to 600 watts, and the speaker cabinet works across a range of zero to 500 watts. The person who asks a question like this (let's call him Wally) needs to SEE the relationship or interaction between the control settings on the instrument (position of the volume and tone controls), the control settings on the amp, the measured output of the amp (oscilloscope or other power measuring device), and the sound in the room (SPL).

    Imagine a video that showed a bass player and a technical guy talking to each other in a studio with a split screen showing the SPL of the conversation. Next, the bass player shows the control settings on the instrument and the amp, and then proceeds to play. At this point, you need a three-way split screen to show 1. the living, breathing, three-dimensional bass player, 2. SPL, and 3. measured output power.

    Wally would be shocked. The bass player on the video could play a single plucked note and let it decay. Watching the measured power output decline down to 1 watt and less as sound continued to come out of the speaker would destroy the wacky anti-science Wally had accumulated over the years. Wally would be astounded at the SPL of one watt. This part might need a tone generator to get a sustained tone that's not possible with a plucked bass.

    Now imagine the web presentation of your specs. When your amp or speaker cabinet specs display "Output Power" or "Power Handling Capacity," each of which are expressed in watts, the spec, e.g., "Output Power" could be a link to the demo video.

    People like Wally need to see and hear what "power" sounds like when it is coming out of a real bass amp and speaker cabinet. Wally needs to see and hear where the bass and amp controls can limit the power to 3 watts yet still be completely audible when driving a speaker cabinet, and how that set of conditions compares to the SPL of two people talking to each other.

    I know that what I'm proposing here is expensive and a pain in the neck to produce, but you only have to do it once. If you put it out on Youtube, suspend the comments. Also, link to the uncompressed video/audio file hosted on your site to ensure users (Wally) can see/hear the original file without the Youtube artifacts that are beyond your control.

    I don't need it, but the spec I think many like Wally need is a range of power/SPL results for speaker cabinets. In other words, show the SPL for 100 watts, 10 watts, 1 watt, 0.1 watt, 0.01 watt, 0.001 watt, all the way down to inaudibility.

    Sorry for the derail. Click here for a refund. Really, just keep clicking.
     
    Heavy Blue, Gearhead17, Cheez and 8 others like this.
  11. JakobT

    JakobT

    Jan 9, 2014
    Oslo, Norway
    Any specifications that will help me set up and run the equipment properly without damage are useful. That usually means power rating and impedance. Weight and dimensions are useful for comparison. Anything beyond that is usually overkill for me.
     
  12. yodedude2

    yodedude2 Supporting Member

    Nov 19, 2005
    san antonio, texas
    i like seeing 180 degree frequency response spl charts (not sure what they're called).
     
  13. This. EV used to provide this kind of data for their cabs in the eighties. Very helpful if one can appreciate it.
     
    bdplaid likes this.
  14. EV used to call them "polar graphs", I believe.
     
    yodedude2 likes this.
  15. Chris Fitzgerald

    Chris Fitzgerald Student of Life Staff Member Administrator

    Oct 19, 2000
    Louisville, KY
    I'm not that knowledgeable when it comes to specs, and always feel that it's best to play and hear for myself. However, since this is getting harder to do in the "deliver it to me sight unseen" culture we live in, there are a couple of things I look at.

    Input impedance
    Sensitivity
    Output impedance ratings of the amplifier i.e. 8ohms vs. 4ohms
    Set points for EQ controls
    Frequency response - the graph idea above is nice

    I don't trust any power ratings these days because I don't know how they are being generated. I have a feeling of what they mean for certain brands, not at all for others.
     
  16. I would like to see an agreed-upon universal standard for power output ratings on amps and power-handling capacities of cabinets.
     
  17. Kro

    Kro Supporting Member

    May 7, 2003
    New Jersey
    There is one chart that I've seen used before by another builder, that I always found interesting: a graph that plots spl against wattage for a given frequency and distance.

    I find this interesting, because if the model used to generate it takes into account mechanical and thermal limits, then it gives a good idea not only of max SPL, but shows a ballpark of the wattage needs to get there (and also potentially where you start to get into diminishing returns).

    I understand that this information can probably be gleaned from other stats as long as they're realistic, but it's just something that I've found helpful in the past from an at-a-glance perspective.

    Of course the frequency used would need to be something appropriately low to be meaningful for bass applications.
     
    Matthijs and gitfiddl like this.
  18. Specs on amps and cabs rarely help me at all.

    My cabs suck on paper but I prefer the sound of them to other cabs which are supposedly so much better.

    With amps wattage and stuff never seems to make any sense because there’s no consistency from one brand to another. I’ve even heard stories of amps that were clearly advertised as 1000w that actually had a 500w power amp module in them. The same 500w module other companies use in their 500w amp. It’s almost like there’s nothing to prevent amp makers from labeling amps as whatever they want. Sometimes it’s a half truth also. Like one amp the wattage rating will be continuous and another it’ll be peak.

    About the only spec that does help is how much the item weighs. This is part of why over 27 years of playing bass I’ve only used a handful of rigs while I’ve gone through dozens of basses and pedals.
     
    The Nameless likes this.
  19. JimChjones

    JimChjones

    Aug 6, 2017
    SE England
    This is something I've been struggling with with home built cabs. I've come to the conclusion that I have no idea what a good sounding (to me) cab looks like on paper other than there's much more to it than a flattish frequency response curve.
     
  20. turcmic

    turcmic

    Jul 30, 2006
    Montreal, QC
    This

    Also, user experience and company support and TB discussions (I agree with your comments on some useless discussions but we can find great technical info here - and your input is of great value!). I’m not a technical guy. If a lot of bass players are satisfied, I will probably be. And when the soundmen tell me I sound good, well, everything is perfect!

    I bought a few amps and cabs (and basses) from online retailers or the classifieds based mainly on user reviews.

    I can appreciate the fact that manufacturers want to publish the best info but you know, some don’t give a damn. And the only valuable standard is electricity at 110v... The industry would have to come up with standard measure procedures made by an independant lab... not gonna happen imho

    Sincere marketing and customer support will always prevail for mass consumers.
     

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