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    Suggestion for a d.i.y speaker

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    tubes4hifi
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    Re: Suggestion for a d.i.y speaker

    Post by tubes4hifi on Wed Aug 24, 2016 3:55 pm

    I agree fully with PeterW comments and with the table that Bob provided, which shows 10X the power to get 10db more sound, so as I said before, that's 10 watts to get to 97db
    with speakers that are 87db at 1 watt. Just a guess, (grab your db meters everybody), but normal listening level is around 80-85db (I just checked with my db meter).
    But let me clarify that when I say 30wpc is plenty (that gives you 100db) I'm also talking about tube power.
    Now I realize that watts are watts (to most people) but I'm sure there is at least 90% agreement that 30w of tube power is equivalent to 100w of SS power.
    Personally, I've used amps ranging from 4wpc to 350wpc. I can definitely hear any SS amp clip at 1% over it's rated output. 350w SS distorts just as bad as 10w SS power.
    It is nearly impossible to hear clipping running a tube power amp at at even 5-10% over it's rated power.
    Just my own opinion of course, but anything over about 200Hz likely never requires more than 10w, at extremely LOUD levels (100db is LOUD, have you used a meter listening at that level??)
    However, yes, especially for music below 100Hz, you're gonna need 10X that much power, maybe even 20X as much power. That's why even super cheap subwoofers start at 100w.
    Most decent quality subwoofers start at 250w and up. Not at all uncommon to see subwoofers running 500-1000w (and of course, that's SS, so they'd better have 10x as much power as you think you need!!)

    RE: speaker kits - I've built 6 or 7 pair over the past 20 years. I'm not a wordworker so I'd recommend you get nice cabinents or be satisfied with whatever your level of non-competance is (like mine is very low).
    Also, unless you are spending more than $500-600 on components alone (speakers & crossovers) not including any cabinent at all, I don't think you can beat commercially available speakers for under $1000.
    I still have a pair of Infinity Primus 360 speakers I bought new ten years ago for $300 that sound better than components I've spend $400 on. PSB makes some great speakers for under $1000, as does Polk.
    My latest DIY speakers cost me about $500 in components and another $500 in cabinetry (that still falls far short of a $500 pair of speakers) that are very nice, but side by side,
    not any better than a $1000 new pair of PSBs which would take 5 minutes out of a box compared to 30-40 hours of build time for DIY.
    I agree with TubeNube, the speaker designs by famed Denmark speaker guru Troels Gravesen are super quality, but will also need cabinents that will require some real word-working ability.
    Finished, they will be compare very well to what you could buy for $2500-4000. Component cost on the TQWT is around $1000 plus cabinents.
    I like the SP44, looks to be around $1500 just for the components.
    Commercially made speakers, as everything else, are a bargain buying used after a few years. Get $10K speakers for maybe $4K.
    86db/w, recommended power 20-50w as per Gravesen.

    Peter W.

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    Re: Suggestion for a d.i.y speaker

    Post by Peter W. on Wed Aug 24, 2016 4:47 pm

    Please note the interpolations. Minor rant warning - NOT directed *at* anyone, but because this is one of my pet peeves!


    quote="tubes4hifi"]I agree fully with PeterW comments and with the table that Bob provided, which shows 10X the power to get 10db more sound, so as I said before, that's 10 watts to get to 97db
    with speakers that are 87db at 1 watt.   Just a guess, (grab your db meters everybody), but normal listening level is around 80-85db (I just checked with my db meter).
    But let me clarify that when I say 30wpc is plenty (that gives you 100db) I'm also talking about tube power.
    Now I realize that watts are watts (to most people) but I'm sure there is at least 90% agreement that 30w of tube power is equivalent to 100w of SS power.

    NONONONONONO!!! The actual difference between "tube" power and SS power is in clipping. Output transformers (nor any other isolated-winding transformer) do not pass DC. So, a tube amplifier will clip much more softly (less harsh clattering and noise) than the typical SS amp. Further, older-design SS amps without built-in speaker protection can pass DC, and can damage voice-coils almost instantly in cases of severe clipping. In either case, at clipping the wave forms are severely truncated - how much additional damage is what is in question. But, below clipping, watts is 100% watts is 100% watts.  

    Personally, I've used amps ranging from 4wpc to 350wpc.  I can definitely hear any SS amp clip at 1% over it's rated output.   350w SS distorts just as bad as 10w SS power.  

    Just so everyone understands how clipping happens: There  is a demand made on the amplifier for some period of time that is greater than the RMS (sustained output capacity) of the amp + the amount of energy stored in its capacitor bank(s) if any. In the case of the venerable Dynaco ST70, that is and extreme of eighty (80) watts for longer than one (1) second. In the case of my Citation 16, that is four hundred (400) watts for longer than one (1) second. Less demand = longer sustained time beyond RMS.

    It is nearly impossible to hear clipping running a tube power amp at at even 5-10% over it's rated power.

    If one knows what to listen for, it is blatantly obvious, but not so harsh - and that is the difference. Clipping with a velvet glove.

    Just my own opinion of course, but anything over about 200Hz likely never requires more than 10w, at extremely LOUD levels (100db is LOUD, have you used a meter listening at that level??)
    However, yes, especially for music below 100Hz, you're gonna need 10X that much power, maybe even 20X as much power.   That's why even super cheap subwoofers start at 100w.
    Most decent quality subwoofers start at 250w and up.   Not at all uncommon to see subwoofers running 500-1000w (and of course, that's SS, so they'd better have 10x as much power as you think you need!!)

    Next Myth: Speaker power ratings. A speaker rated at 25 watts (a great deal) will sustain 25 watts of power for ever, and ever, amen. That is the functional equivalent of putting a 25-watt light bulb inside the speaker, as far as heat is concerned.  But, that same speaker will sustain, easily, 1,000 watts  for a few seconds. Point being that it is underpowered amplifiers driven to clipping that are far more likely to damage speakers (passing DC, and so forth) than over-powered amplifiers operating within normal listening levels. Sure, if one is listening to head-banging music at ear-bleed levels, then there will be issues. But, I routinely drive my 40-watt AR M5 speakers from a 150 watt amp at substantial levels without fear of damage. If a woofer is well-and-truly rated at 250 watts, that means it can sustain a 500 Hz sine wave at 250 watts pretty much forever. Somehow, that is quite dubious outside of concert hall reinforcement speakers - and that is emphatically a special case.

    RE: speaker kits - I've built 6 or 7 pair over the past 20 years.  I'm not a wordworker so I'd recommend you get nice cabinents or be satisfied with whatever your level of non-competance is (like mine is very low).
    Also, unless you are spending more than $500-600 on components alone (speakers & crossovers) not including any cabinent at all, I don't think you can beat commercially available speakers for under $1000.
    I still have a pair of Infinity Primus 360 speakers I bought new ten years ago for $300 that sound better than components I've spend $400 on.   PSB makes some great speakers for under $1000, as does Polk.
    My latest DIY speakers cost me about $500 in components and another $500 in cabinetry (that still falls far short of a $500 pair of speakers) that are very nice, but side by side,
    not any better than a $1000 new pair of PSBs which would take 5 minutes out of a box compared to 30-40 hours of build time for DIY.
    I agree with TubeNube, the speaker designs by famed Denmark speaker guru Troels Gravesen are super quality, but will also need cabinents that will require some real word-working ability.  
    Finished, they will be compare very well to what you could buy for $2500-4000.   Component cost on the TQWT is around $1000 plus cabinents.  
    I like the SP44, looks to be around $1500 just for the components.
    Commercially made speakers, as everything else, are a bargain buying used after a few years.   Get $10K speakers for maybe $4K.
    86db/w, recommended power 20-50w as per Gravesen.  [/quote]

    Legacy speakers properly maintained will _always_ be a bargain as compared to anything new or that can be built via DIY sources.

    I paid $600 for my pair of Magnepan MGIIIas, $200 for my par of AR3as, $40 for my Athena set, $40 for my AR4x, $125 for my M5s, all in excellent, clean and well-maintained condition. That advice is 100% true without reservation.

    tubes4hifi
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    Re: Suggestion for a d.i.y speaker

    Post by tubes4hifi on Wed Aug 24, 2016 6:28 pm

    yup, agreed!  did someone ask about speaker power ratings?  didn't see that anywhere.   I was referring to POWERED subwoofers which have their own low-freq amp built it.
    Use a 30w tube amp, and a 250w powered sub-woofer, and if those dont' blow you out of the room, well, yeah, go for those 100db speakers.
    Then you can get by with 4w or less.  And yes, I never denied that excess power is nice - just like it is in a sports car!
    Just saying . . . how much power do you NEED?   How much $$ do you need?   some less than others! I'll shut up now !!!

    vtshopdog

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    Re: Suggestion for a d.i.y speaker

    Post by vtshopdog on Wed Aug 24, 2016 8:18 pm

    I too am planning a DIY speaker build and have been researching various sources for a while.  Have built some smaller kits but next project will be more upscale.   Here is my list of good DIY speaker kit sites, many have been listed in this thread already:

    Troels Gravesen - even if you don't find something you want there is a wealth of construction information in the "tips" page.  Don't ignore 3-way classic designs, lots of bang for the buck and fairly easy carpentry.

    Humble homemade hifi - Tony Gee, he is the author of a crazy large capacitor test doc but offers several kits and there is a very large library of legacy designs dating back about 20 years. Top dollar stuff, some with extreme top dollar filter networks.  His pending SB  Satori based 3-way has caught my eye but drivers not available for another month or so.

    Madisound - assume everyone has looked here?

    Meniscus - Jeff Bagby kits look nice, I built one of the Paul Carmody kits a few years back and was very pleased.

    Zaph Audio - some designs also available at Madisound

    Selah Audio - Rick Craig, super nice guy, specializes in custom designs that seem to mostly be based on 3 cabinet constructions (2-way & 3-way monitors and a floor stander). He has a 90db floor stander based on Satori drivers that looks real nice.  Besides Selah web site check his vendor site on Audiocircle where most the custom stuff gets displayed.  

    I don't think anyone mentioned Parts Express. Their packaged kits are mostly pretty basic but the "Speaker Talk" forum is full of information if you have the patience to navigate

    Lastly, do your homework on imported kits as there will be currency exchange fees and customs duties that will likely add 8-12% (or more) to cost

    colin86325

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    Re: Suggestion for a d.i.y speaker

    Post by colin86325 on Thu Aug 25, 2016 12:13 pm

    I'm pretty pleased with the FrugleHorn 3 speakers that I built using a flatpack kit from Planet10.  I don't have any woodworking tools/skills, so this was a good option for me.

    http://www.diyaudio.com/forums/planet-10-hifi/184088-frugel-horn-mk3-flat-paks.html

    Dogstar

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    Re: Suggestion for a d.i.y speaker

    Post by Dogstar on Fri Aug 26, 2016 1:09 am

    I know I made a mistake about the power to volume level but as has been pointed out by others a lower powered amp needs more efficient speakers in order to allow the music to have the dynamic range it needs if it's s good recording. Most recordings of new music compress the sound so much that the difference between a cannon blast and needle drop is ridiculously not there.

    Anyway I've seen the Troeks Graveson web site for years and the designs and documentation is very impressive. The TQWT speakers look like a project I can handle without getting too complicated. However I'm looking for the main page for the Mk III's and I can't seem to find it. If you could paste a link to it as well as a link to the BOM that'd help me a lot. Thanks.

    corndog71

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    Re: Suggestion for a d.i.y speaker

    Post by corndog71 on Fri Aug 26, 2016 12:34 pm

    I respectfully disagree that speaker kits can't beat commercial designs. GR Research sells kits that compete with models costing 2-3x more. Danny Richie's designs for commercial companies have won numerous awards and critical praise. Best of all he loves to bring what he's learned down to the budget-conscious DIY types. He can also measure an older speaker and build a much better crossover that'll make them sound their best. (The crossovers in commercial speakers are almost always compromised by cheap parts.)

    There's one other factor missed about building your own speakers. The pride you get from building your own. There's a lot of that here with tube amps and it can be found with speakers too.

    Peter W.

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    Re: Suggestion for a d.i.y speaker

    Post by Peter W. on Fri Aug 26, 2016 12:48 pm

    corndog71 wrote:I respectfully disagree that speaker kits can't beat commercial designs.  GR Research sells kits that compete with models costing 2-3x more.  Danny Richie's designs for commercial companies have won numerous awards and critical praise.  Best of all he loves to bring what he's learned down to the budget-conscious DIY types.  He can also measure an older speaker and build a much better crossover that'll make them sound their best.  (The crossovers in commercial speakers are almost always compromised by cheap parts.)

    There's one other factor missed about building your own speakers.  The pride you get from building your own.  There's a lot of that here with tube amps and it can be found with speakers too.  

    I don't think that anyone here expressed or implied that home-built kits cannot compete with the best of commercial designs. I believe the statements were more along the lines of what may be paid for a top-flight legacy speaker as compared to a top flight new kit. And, some types of speakers (planars, for example) are exceedingly difficult to make outside of controlled factory conditions, such that they are almost (but not entirely) beyond the scope of a DIYer. And electrostatic speaker kits approach and can exceed $5,000 as kits.

    Writing entirely for myself - as I am still working full time - I think that speakers are probably the last thing I might attempt as a DIY project. Here in the eastern part of the US, north of the Mason-Dixon line, legacy equipment of all types and styles is thick on the ground, and speakers, for some reason, tend to run cheap. And I have the skills to re-surround, even re-cone as needed, so I often see some genuine exotica for very cheap prices. Most of my time in the hobby is spend refurbishing/upgrading legacy equipment that has been let go at very cheap prices, scavenged from dumpsters or curbside finds. I am about four projects deep at this moment....

    But, agreed 100% that the satisfaction from a successful DIY project, especially one that is not simple recipe-following, is unsurpassed.

    Tube Nube

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    Re: Suggestion for a d.i.y speaker

    Post by Tube Nube on Fri Aug 26, 2016 7:36 pm

    Much as I adore my DIY Troels' speakers, I still kick myself that I didn't have a spare $600. the day I saw a pair of Quad ESL's advertised locally.

    Doh, doh, doh, doh dohhhhhh!

    edgobb

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    Re: Suggestion for a d.i.y speaker

    Post by edgobb on Tue Sep 13, 2016 10:22 pm

    Just to throw my 2¢ onto this dead horse...

    I went on this quest a couple years ago. I didn't want to spend a fortune and I really wanted to scratch build a set of speakers. I eventually found the designs of Paul Carmody and ended up using his Sunflower design as my first speaker building project.

    I sourced all the parts, designed the cabinets to my specifications and away I went! Like Roy, woodworking is not my forte. My experience taught me that the more you sand, the lower your standards get. Very Happy Anyway they sound great, but I am wishing for more bass in my untreated, oddly shaped, vaulted ceiling, with windows behind me listening room.

    It was a rewarding experience, but ultimately not as enjoyable for me as building the electronics. I had the most fun designing the crossover layout and putting it together. But now I built everything in my system with my own hands, and that is a pretty cool thing. (Except my Rega turntable)

    Here is the link to Paul's design page, and you can find a lot of build threads for his stuff out there in forums. Paul Carmody's Page

    Roy, I know you emailed me a year ago asking about those speakers and I didn't answer...that email got lost in my oblivion and I just remembered. Sorry about that. Embarassed

    Happy fall all!
    -Ed

    Dogstar

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    Re: Suggestion for a d.i.y speaker

    Post by Dogstar on Wed Sep 14, 2016 1:18 am

    Currently I have Polk Audio LSiM 703 speakers that I bought shortly after I got my VTA ST-120 and was very happy with how clean and precise the sound was in my less ideal room that wasn't optimized for audio. I got the 'custom' Heresy speakers in 2014 and at first was disappointed with the speakers because of how bad they look. But after a while I find that they really are very good speakers to me. IMO I think they are on the same level of sound quality as the JBL L100T3's that I also have. The JBL's also sound very good but I think they are better suited to a higher powered amp.

    I'm thinking that now that I have a place to do woodworking I should maybe start out by rebuilding the Heresys by building nicer cabinets. Rather than MDF I'm thinking birch plywood. And rather than attempting veneer I should just finish the birch plywood since they have a finished surface. My only concern is the plywood will sound different than the MDF. The only thing I'd loose is the cost of the plywood and my time since I'll be using all the existing drivers and crossovers. But the time spent will give me the experience to improve my skill. Or maybe i will be happy with the sound . I guess it wouldn't hurt to try.

    Tube Nube

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    Re: Suggestion for a d.i.y speaker

    Post by Tube Nube on Wed Sep 14, 2016 1:36 am

    Say Dog,

    When I built my speakers last summer (and fall...and winter) i used birch ply for the most part (baltic birch), and "edged" it with 1/4" birch hard wood. No plys anywhere to be seen. The varathane finish ended up a little darker drying on the hard wood. I rather like the accented look. I suspect it was easier than working with veneer. Besides. Veneer seems somehow fraudulent to my quirky mind.

    Regarding sound, I think there's no way ply would be worse than MDF. Apparently MDF absorbs then releases energy (vibration, i.e., sound), slightly muddying the sound. Baltic birch is superior in this respect. Of course, mdf is commonly used in speaker construction--even very expensive speakers, so I dont know if this "problem" actually adds up to a hill of beans, but we DIYers have the luxury of not having to take that short cut.

    corndog71

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    Re: Suggestion for a d.i.y speaker

    Post by corndog71 on Wed Sep 14, 2016 9:38 pm

    My understanding is that mdf can work just fine with proper bracing. Real wood is not typically used because it can add vibration and color the sound. Baltic birch is a good option too. I would also recommend No Rez from GR Research for lining the cabinets which helps reduce cabinet resonances further and really cleans up the mids and tighten bass.

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