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  • This amp sounds like fun...

    You've just got to love Class D amps - they allow things like 500 watt 2x10 bass combo amps that weigh less than 35 pounds to exist.


    Did you folks see the new Hartke HD500 in today's HC News?




    If not, you should check out the front page once in a while - you never know what you might see there.


    http://www.harmonycentral.com/news/h...500-bass-combo


    I've already got the review lined up. Stay tuned!
    **********

    "Look at it this way: think of how stupid the average person is, and then realize half of 'em are stupider than that."

    - George Carlin

    "It shouldn't be expected that people are necessarily doing what they appear to be doing on records."

    - Sir George Martin, All You Need Is Ears

    "The music business will be revitalized by musicians, not the labels or Live Nation. When the musicians decide to put music first, instead of money, the public will flock to the fruits and the scene will be healthy again."

    - Bob Lefsetz, The Lefsetz Letter

  • #2
    Sounds cool, at least on paper. If I played bass on a more regular basis I'd probably opt for something similar. TC Electronic Class D amps crop up on CraigsList occasionally.
    Official HCAG “Theory-Challenged Hack”
    Member of the IBANEZ ACOUSTIC ASSASSINS
    Proud Member of The Alvarez Alliance
    Member of the Schecter Society
    Person-2-Person on the Web

    Comment


    • #3
      Two 10"s can move only so much air, no matter how much power you put into them.
      "The Web puts all of the world's knowledge at our fingertips; unfortunately it's mixed with all of the world's bull****************."
      -- Bob Parks

      "A thing is not necessarily true because a man dies for it."
      -- Oscar Wilde

      "No man dies for what he knows to be true. Men die for what they want to be true, for what some terror in their hearts tells them is not true."
      -- Oscar Wilde

      "It is a trap of history to believe that eyewitnesses remember accurately what they have lived through."
      -- Theodore White

      Comment


      • #4
        Originally posted by isaac42 View Post
        Two 10"s can move only so much air, no matter how much power you put into them.
        Which is why God made extension cabs. Unfortunately, this particular amp must be an atheist because it doesn't have a connection for one. It's probably a fine amp within its limits and it does have an XLR Out for connecting to a PA.
        Last edited by DeepEnd; 09-24-2017, 03:23 PM.
        Official HCAG “Theory-Challenged Hack”
        Member of the IBANEZ ACOUSTIC ASSASSINS
        Proud Member of The Alvarez Alliance
        Member of the Schecter Society
        Person-2-Person on the Web

        Comment


        • #5
          Originally posted by isaac42 View Post
          Two 10"s can move only so much air, no matter how much power you put into them.
          True, although it's still one of my favorite speaker configurations for bass. Add a 15" and maybe a horn and it's dang near perfect IMO.
          **********

          "Look at it this way: think of how stupid the average person is, and then realize half of 'em are stupider than that."

          - George Carlin

          "It shouldn't be expected that people are necessarily doing what they appear to be doing on records."

          - Sir George Martin, All You Need Is Ears

          "The music business will be revitalized by musicians, not the labels or Live Nation. When the musicians decide to put music first, instead of money, the public will flock to the fruits and the scene will be healthy again."

          - Bob Lefsetz, The Lefsetz Letter

          Comment


          • #6
            It would definitely need an extension cab (preferably a 15") to sound balanced with a drummer.
            I'm not a big fan of Hartke speakers however. Every bass player I've known or spoken to all steer away from them. They all say the same thing. The aluminum cones shred prematurely and you're much better off with paper cones. Companies who recone speakers don't touch them either.

            As far as the amp itself, I have a 350W Ampeg Portaflex which is a class D amp.

            You need to realize they get that wattage rating using a fixed test tone, usually a 1000Hz which is used to push the amps input till it begins to clip.
            Unfortunately its a very different thing compared to pushing am amp with sharp transients which go from zero to maximum wattage and actual musical tones producing music.

            I've run that class D Ampeg side by side with other bass amps I own and half of the wattage is unusable for getting nice round musical bass tones. Its sweet spot is around 50% and you can maybe push it to around 75% tops. Any higher and it starts to sound nasty. Its mainly how the strings begin to feel when you dig in. The transient peaks tell you there simply isn't any more clean headroom. (especially when using humbucker bass pickups)

            I gestimate the amp may have 250 usable watts. It doesn't matter to me what its wattage is under lab conditions pushing the head with a test tone that has no transients. Since the amp is used in the real world, only its real world wattage matters. (My 200W Crate head which uses older transistors produces the same loudness at 3/4 up compared to the Portaflex running in its sweet spot)

            A 500W class D is likely a match for the Ampeg V4B which was a 100W tube amp I used to own.

            I do plan to upgrade the 350W Portaflex for a 500W at some point because the 350w craps out too easily running by itself with the cabs I own. With the 500 I should be able to run it at 50% and get a clear tone with plenty of headroom for transients. (This is what you'd need playing with a live rock drummer).

            I like the idea of that amp being light but the 2X10's doesn't cut it for me. I auditioned a bass player using a similar rig about a year ago. He had plenty of volume but it's footprint didn't couldn't match an un-miced kick drum.

            A Kick drum is like a 24" speaker and moves allot of air when properly tuned. The shell produces bass resonance like a speaker cab does.
            2X10's is only 20" and you need the bass to match or sound larger then kick drum. This has less to do with volume then it does the tone of the air being moved. Too much midrange from a bass guitar interferes with guitar frequencies. Maybe if the drummer uses one of those mini kick drums and the guitarists are using mini combo's with 8's you might get a mix balance but I'd need a 15 with those 10's to get the sub lows I'm used to, especially with some of the basses I use.


            Comment


            • #7
              Originally posted by WRGKMC View Post
              . . . A Kick drum is like a 24" speaker and moves allot of air when properly tuned. The shell produces bass resonance like a speaker cab does.
              2X10's is only 20" and you need the bass to match or sound larger then kick drum.
              2X10 is not 20''. We're talking about area, which is different from diameter. With 1'' all around for surround and frame, a pair of 10'' speakers has a cone area of about 100 sq. in. or equal to a single speaker with a cone diameter of about 11.3'' or about 13.3'' with frame and surround. Figure somewhere between a single 12'' and a single 15''.
              Last edited by DeepEnd; 09-25-2017, 05:11 PM.
              Official HCAG “Theory-Challenged Hack”
              Member of the IBANEZ ACOUSTIC ASSASSINS
              Proud Member of The Alvarez Alliance
              Member of the Schecter Society
              Person-2-Person on the Web

              Comment


              • WRGKMC
                WRGKMC commented
                Editing a comment
                I wasn't talking about square inches I was talking about the distance across the two.

                If you want to get technical, The area of circle is pi times the square of its radius.Area = π * Radius2 which equals 78.54 per 10" speaker. Multiply it times two winds up being 157.08 inches squared (not 100)

                If you calculate a 24" kick its 452.389342 inches squared which is more then double two 10's. This is why 4X10's are commonly used to match a drummers kick. 4 X 78.54 = 314.16 which is much closer to most kick drums.
                Last edited by WRGKMC; 09-26-2017, 07:21 AM.

              • DeepEnd
                DeepEnd commented
                Editing a comment
                Sorry but no. ''the distance across the two'' isn't the same as cone area. Speaking of cone area, you don't include the frame and surround when calculating cone area, just the part of the speaker that moves and drives air. In the same way, you don't measure engine displacement by measuring the outside of the block, just the volume of the cylinders. Thus, if you deduct an inch all around to make it simple, the cone area of a nominal 10'' speaker is closer to 4^2*Pi or 50.26548 square inches. Even if you include the surround, there's still half an inch or so all around for frame. Twice that (for two speakers) is 100.5309649 square inches. A single 15'' is about 132.7322896 square inches or 265.464579 square inches for a pair.

                In the case of a drum, the whole head is vibrating and, according to your reasoning, you'd need a single 26'' speaker or about nine 10's or about three 15's to come near equaling it. A pair of 4X10 cabs would come pretty close.

            • #8
              Originally posted by WRGKMC View Post
              A Kick drum is like a 24" speaker and moves allot of air when properly tuned. The shell produces bass resonance like a speaker cab does.
              2X10's is only 20" and you need the bass to match or sound larger then kick drum. This has less to do with volume then it does the tone of the air being moved. Too much midrange from a bass guitar interferes with guitar frequencies. Maybe if the drummer uses one of those mini kick drums and the guitarists are using mini combo's with 8's you might get a mix balance but I'd need a 15 with those 10's to get the sub lows I'm used to, especially with some of the basses I use.
              My studio monitors only have 8" drivers (two per cabinet), so by your logic, they shouldn't be able to reproduce a well-recorded kick drum, and they should have too much midrange. Yet they're flat down to 35 Hz.

              The size of a speaker has little to do with its frequency response. And it has practically nothing to do with its efficiency, how loud it can get, or the amount of power it can handle.

              As someone else already pointed out, even a pair of 15" speakers is lacking in terms of overall cone surface area in comparison to a 24" kick drum, and yet if they're efficient enough and they have the right frequency response and they're mounted in a decent cabinet and coupled with a sufficiently powerful amp, they should have no problem blowing that kick drum off the stage in terms of the maximum SPL each is capable of generating.

              Finally, the anecdotal evidence - I used a solid state 200W 2x10 Eden combo with a rock band for years at indoor and outdoor gigs, and I never felt I was underpowered, or lacking in lows, or that I couldn't keep up with the drummer in terms of volume. I had all of the low frequency punch I wanted / needed. Now maybe if I was running sound at a Rave, or using a synth bass and pumping out lots of subharmonic content, I might have felt differently, but in a rock band, it worked fine. Plus, there's always the line out - run that to the PA, and now we're talking about subs and thousands of watts of power - your stage amp is just a personal monitor at that point - FOH has all the power and authority they need to produce crushing amounts of bass in the house mix.
              **********

              "Look at it this way: think of how stupid the average person is, and then realize half of 'em are stupider than that."

              - George Carlin

              "It shouldn't be expected that people are necessarily doing what they appear to be doing on records."

              - Sir George Martin, All You Need Is Ears

              "The music business will be revitalized by musicians, not the labels or Live Nation. When the musicians decide to put music first, instead of money, the public will flock to the fruits and the scene will be healthy again."

              - Bob Lefsetz, The Lefsetz Letter

              Comment


              • #9
                Sorry but no. ''the distance across the two'' isn't the same as cone area. Speaking of cone area, you don't include the frame and surround when calculating cone area, just the part of the speaker that moves and drives air. In the same way, you don't measure engine displacement by measuring the outside of the block, just the volume of the cylinders. Thus, if you deduct an inch all around to make it simple, the cone area of a nominal 10'' speaker is closer to 4^2*Pi or 50.26548 square inches. Even if you include the surround, there's still half an inch or so all around for frame. Twice that (for two speakers) is 100.5309649 square inches. A single 15'' is about 132.7322896 square inches or 265.464579 square inches for a pair.

                In the case of a drum, the whole head is vibrating and, according to your reasoning, you'd need a single 26'' speaker or about nine 10's or about three 15's to come near equaling it. A pair of 4X10 cabs would come pretty close.

                Man you really need to get a life and keep things in perspective. I don't give a rats rear about exactly how many square inches there actually are.

                I do suggest you google up an on line calculator because your math simply isn't correct for a circle. http://www.rvick.com/CircleCalculator.htm

                A 15" speaker has 176 square inches not 132.
                A single 10" speaker has 78 square inches not 50.
                A 24 inch circle has 452 square inches.

                If you subtract an inch for the mounting edge you'd get 63" square but why bother?

                Speakers are cone shaped which gives you back that additional surface area so subtracting the speaker edges is a waste of time.

                Even if you account for the drum edges its still going to dwarf two ten inch speakers which was my point.

                Again, If you like the wimpy sound of two tens, go for it man. That's your opinion and I respect that.

                You don't have to try and convince me with your arguments two tens can match a larger kick because I own enough cabs including 2X10's with bass speakers to know they suck for tone. I don't care what kind of speakers they are or what kind of head drives them, they don't match the footprint of an acoustic drummer. A kick drum is only part of it. A drum set takes up an area of around 6' across and 4~5' high, and a good 4~5' deep.

                Again, I'm simply expressing my opinion and my preferences based on my first hand experience.

                If you have an opinion that differs go ahead and make it. I think it will fall on deaf ears of most professional players like myself but maybe its the fact that your needs don't match theirs which is exactly where that difference in opinion truly lies.

                Comment


                • #10
                  Originally posted by Phil O'Keefe View Post

                  My studio monitors only have 8" drivers (two per cabinet), so by your logic, they shouldn't be able to reproduce a well-recorded kick drum, and they should have too much midrange. Yet they're flat down to 35 Hz.

                  The size of a speaker has little to do with its frequency response. And it has practically nothing to do with its efficiency, how loud it can get, or the amount of power it can handle.

                  As someone else already pointed out, even a pair of 15" speakers is lacking in terms of overall cone surface area in comparison to a 24" kick drum, and yet if they're efficient enough and they have the right frequency response and they're mounted in a decent cabinet and coupled with a sufficiently powerful amp, they should have no problem blowing that kick drum off the stage in terms of the maximum SPL each is capable of generating.

                  Finally, the anecdotal evidence - I used a solid state 200W 2x10 Eden combo with a rock band for years at indoor and outdoor gigs, and I never felt I was underpowered, or lacking in lows, or that I couldn't keep up with the drummer in terms of volume. I had all of the low frequency punch I wanted / needed. Now maybe if I was running sound at a Rave, or using a synth bass and pumping out lots of subharmonic content, I might have felt differently, but in a rock band, it worked fine. Plus, there's always the line out - run that to the PA, and now we're talking about subs and thousands of watts of power - your stage amp is just a personal monitor at that point - FOH has all the power and authority they need to produce crushing amounts of bass in the house mix.
                  I wish that were true for me! None of my bands has a PA with a sub, and none has thousands of watts. Only one venue we play has a system like that, and we play there only once a year or so. Life is different in a small town.
                  "The Web puts all of the world's knowledge at our fingertips; unfortunately it's mixed with all of the world's bull****************."
                  -- Bob Parks

                  "A thing is not necessarily true because a man dies for it."
                  -- Oscar Wilde

                  "No man dies for what he knows to be true. Men die for what they want to be true, for what some terror in their hearts tells them is not true."
                  -- Oscar Wilde

                  "It is a trap of history to believe that eyewitnesses remember accurately what they have lived through."
                  -- Theodore White

                  Comment


                  • #11
                    I'm currently playing most gigs with a rack system using one of two preamps and a Crown XLS 1500 class D power amp. It's rated at 300w into an 8 ohm load, using one channel. I have run it all out, even had the protection circuit shut it down a time or two, and it has never sounded nasty.
                    "The Web puts all of the world's knowledge at our fingertips; unfortunately it's mixed with all of the world's bull****************."
                    -- Bob Parks

                    "A thing is not necessarily true because a man dies for it."
                    -- Oscar Wilde

                    "No man dies for what he knows to be true. Men die for what they want to be true, for what some terror in their hearts tells them is not true."
                    -- Oscar Wilde

                    "It is a trap of history to believe that eyewitnesses remember accurately what they have lived through."
                    -- Theodore White

                    Comment


                    • #12
                      Originally posted by WRGKMC View Post
                      Man you really need to get a life and keep things in perspective. I don't give a rats rear about exactly how many square inches there actually are.

                      I do suggest you google up an on line calculator because your math simply isn't correct for a circle. http://www.rvick.com/CircleCalculator.htm

                      A 15" speaker has 176 square inches not 132.
                      A single 10" speaker has 78 square inches not 50.
                      A 24 inch circle has 452 square inches.

                      If you subtract an inch for the mounting edge you'd get 63" square but why bother?

                      Speakers are cone shaped which gives you back that additional surface area so subtracting the speaker edges is a waste of time.

                      Even if you account for the drum edges its still going to dwarf two ten inch speakers which was my point. . . .
                      Let's see if I can straighten this out. First, I said 1'' all around, which means the cone of a 10'' speaker is 8'' across. Here's a quick and dirty pic to illustrate:
                      Click image for larger version

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                      The outer circle is the frame, the next in is the surround, and the next is the cone. I added the dust cap for grins. In the specs of a Jensen P10Q you'll notice that the frame is 259mm (10.19685'') in diameter while the surround is 231mm (9.094488'') in diameter. We know the surround isn't going to extend past the lip of the frame. That's 1.102362'' just for the frame. Once you add in the surround it's probably closer to 2'', which was my original point. (https://www.jensentone.com/vintage_alnico/p10q). Plus, a speaker acts as a piston at lower frequencies so we're only interested in its cross sectional area, not its total surface area.

                      I never said two 10's could match the surface of a 24'' kick drum, I said it would take about nine 10's and that a pair of 4X10 cabs would come close. We're only interested in the part of the drum that produces sound, which means the head. It doesn't matter how deep the kit is or how tall. That's air for resonance but it doesn't actually produce sound any more than the air in a speaker cab. Finally, I know you don't care how many square inches of cone area there are because it proves you're wrong.
                      Official HCAG “Theory-Challenged Hack”
                      Member of the IBANEZ ACOUSTIC ASSASSINS
                      Proud Member of The Alvarez Alliance
                      Member of the Schecter Society
                      Person-2-Person on the Web

                      Comment


                      • WRGKMC
                        WRGKMC commented
                        Editing a comment
                        That's fine then. I didn't understand why you were beating a dead horse.

                        By the way you can google up a calculator that calculates the surface area of a cone. I did a quick test based on an 8" surface area as you suggested and used a 3" cone depth the difference goes from 50" to 87"

                      • DeepEnd
                        DeepEnd commented
                        Editing a comment
                        See isaac's explanation below about pistons. The depth of the cone doesn't matter.

                    • #13
                      The conical shape of a speaker cone doesn't add any effective radiating area. To understand this, imagine a piston pushing a fluid through a tube. Initially, the shape of the piston might make a difference, but once the piston has pushed out the substance (whatever it is. Maybe clay?), slice off whatever has come out. From then on, no matter what shape the piston takes, the substance pushed out will always form a disk. The piston is a concave cone? Disk. Convex cone? Disk. Hemishpere? Disk. And so on. The result is that the effective radiating area is that of a flat disk, so that is how we determine the effective radiating are of a speaker.
                      "The Web puts all of the world's knowledge at our fingertips; unfortunately it's mixed with all of the world's bull****************."
                      -- Bob Parks

                      "A thing is not necessarily true because a man dies for it."
                      -- Oscar Wilde

                      "No man dies for what he knows to be true. Men die for what they want to be true, for what some terror in their hearts tells them is not true."
                      -- Oscar Wilde

                      "It is a trap of history to believe that eyewitnesses remember accurately what they have lived through."
                      -- Theodore White

                      Comment


                      • WRGKMC
                        WRGKMC commented
                        Editing a comment
                        Not sure what you mean by slicing off. A speaker compresses air as it pushes out and decompresses when it sucks in but I agree with the rest. The cone shape if for rigidity, otherwise a flat surface would flex.
                        This is only a problem with low frequencies that produce allot of piston movement. Mid drivers and tweeters are often edge to edge with no surround. They don't need a surround because the frequencies are so high its not needed

                      • isaac42
                        isaac42 commented
                        Editing a comment
                        It's just an analogy. The point is that the shape of the piston - in this case, a speaker cone - doesn't affect the effective area.
                        Last edited by isaac42; 09-28-2017, 10:09 AM.












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