It's a clickbaity-ish title...
LIFE STORY FOR PEOPLE WHO CARE FOR THEM:
My fronts are a mess, I made the boxes 20 years ago, got the math wrong, made the box too small, improved it by isobarically loading the woofers, blew those woofers, replaced them with 8" Goldwood GW-8PC-4 I recently added some mids, HiVi DMN-A/DM-7500 after swapping them from the Morel CAM 558, but I have them in a separate box on top of the old box.
I'm still not happy with them, after other things I looked at, changing from a stereo valve based amplifier to a pair of pass labs monoblocks, upgrading the DAC Opamps to Burson V6 Classics, anyway, I came across a new calculator on mh-audio.nl
http://www.mh-audio.nl/Calculators/CalcMaxFreq.html
I think that the mids are too far apart from the tweeters (45cm, woofer in between, compared to the recommended 5cm centre to centre) but coming up with a solution to that has lead me to talking my wife into a major upgrade.
TLDR
I punched the numbers into http://www.mh-audio.nl/Calculators/BIBalt.html and combined with a second pair of isobaric Goldwood woofers I now have a beautiful behemoth spec'd out for me, 2 metres tall, a foot wide, I can get the wood cut easily too.
but now I have questions before I pull the trigger.
has anyone here had experience with one? What was it like?
I'm planning on a D'apollito lineup, isobaric woofers above and below the HiVi mid horizontally aligned to a Dayton Audio PT2C-8 Planar Tweeter but I haven't seen any like this yet, it's mostly full ranges, is there a reason for this I missed?
There doesn't seem to be a lot of damping, are the sides meant to be damped?
Some have flanges on them, I found a picture that shows how they can affect the response, does anyone else know of other info on them?
LIFE STORY FOR PEOPLE WHO CARE FOR THEM:
My fronts are a mess, I made the boxes 20 years ago, got the math wrong, made the box too small, improved it by isobarically loading the woofers, blew those woofers, replaced them with 8" Goldwood GW-8PC-4 I recently added some mids, HiVi DMN-A/DM-7500 after swapping them from the Morel CAM 558, but I have them in a separate box on top of the old box.
I'm still not happy with them, after other things I looked at, changing from a stereo valve based amplifier to a pair of pass labs monoblocks, upgrading the DAC Opamps to Burson V6 Classics, anyway, I came across a new calculator on mh-audio.nl
http://www.mh-audio.nl/Calculators/CalcMaxFreq.html
I think that the mids are too far apart from the tweeters (45cm, woofer in between, compared to the recommended 5cm centre to centre) but coming up with a solution to that has lead me to talking my wife into a major upgrade.
TLDR
I punched the numbers into http://www.mh-audio.nl/Calculators/BIBalt.html and combined with a second pair of isobaric Goldwood woofers I now have a beautiful behemoth spec'd out for me, 2 metres tall, a foot wide, I can get the wood cut easily too.
but now I have questions before I pull the trigger.
has anyone here had experience with one? What was it like?
I'm planning on a D'apollito lineup, isobaric woofers above and below the HiVi mid horizontally aligned to a Dayton Audio PT2C-8 Planar Tweeter but I haven't seen any like this yet, it's mostly full ranges, is there a reason for this I missed?
There doesn't seem to be a lot of damping, are the sides meant to be damped?
Some have flanges on them, I found a picture that shows how they can affect the response, does anyone else know of other info on them?
The specs of the Goldwoods imply they'd do well in a conventional BR. Re:'I'm still not happy with them' = more info??
No direct experience, but it is said "The main problem of the TQWT is that it will produce a comb filter effect due to line resonances at lower frequencies, a very uneven and lumpy bass response”
No direct experience, but it is said "The main problem of the TQWT is that it will produce a comb filter effect due to line resonances at lower frequencies, a very uneven and lumpy bass response”
A few things:
I would sort out your loudspeaker design before moving to Pass Monoblocks and expecting them to fix your problems. I test my speakers with a $200 pioneer receiver and still haven’t hit the limit of what speaker improvements can do for the sound.
I have no experience with Goldwood or Hivi drivers, but my impression from reviews is they are on the cheaper end and not that great. It sounds like you didn’t especially like them in your first design, so maybe try something else?
While I like well-designed big speakers, they are not necessarily better. Size is just part of the holistic design and depends on the TS parameters of your drivers and the enclosure type.
The design you’re proposing could work. That said, usually drivers are stacked vertically so that multi-source interference in the crossover region is restricted to vertical head movement.
More details on your goals and proposed design would help us better assess the idea.
I would sort out your loudspeaker design before moving to Pass Monoblocks and expecting them to fix your problems. I test my speakers with a $200 pioneer receiver and still haven’t hit the limit of what speaker improvements can do for the sound.
I have no experience with Goldwood or Hivi drivers, but my impression from reviews is they are on the cheaper end and not that great. It sounds like you didn’t especially like them in your first design, so maybe try something else?
While I like well-designed big speakers, they are not necessarily better. Size is just part of the holistic design and depends on the TS parameters of your drivers and the enclosure type.
The design you’re proposing could work. That said, usually drivers are stacked vertically so that multi-source interference in the crossover region is restricted to vertical head movement.
More details on your goals and proposed design would help us better assess the idea.
Already made the move to the Pass Labs monoblocks, but still have the stereo EL34 amp in storage.
But, yeah, I've started cheap, I have an old 5.1 Yamaha receiver ready to test with I guess, I saw it as an opportunity to get the most out of my system as far as upgrades are concerned, like you said, you have a cheap Pioneer amp and still find Speaker upgrades to be the most rewarding.
I had and enjoyed my Re/Sponse 8" woofers paired with a Behringer iNuke but I turned them into a smoke and sparkler machine after testing the current draw on the nobsound preamps, the Goldwoods matched the specs for replacements, but they just haven't sounded the same either, the Sabaj A8's I replaced the iNuke with are just so transparent they're funkillers, I'm not afraid of getting different woofers, but this is an unexpected interim upgrade from a different major upgrade I had in mind, but this idea seems to solve these problems right now.
My "crossover" is software based, it's a custom PC between the CD transport and the (four) DAC's, I currently wonder if the midrange issue I'm having comes from it's distance from the tweeter (pic related), where the aforementioned mh-audio calculator recommends a much closer vertical distance to avoid lobing, -5cm @3.5khz- centre to centre, less distance than the mid dome is to it's surround, let alone the basket's sizeable frame, then the (usual) flange around the tweeter, which suggests a close flat horizontal alignment would make for a better vertical response with minimal difference horizontally.
So far I've based my system choices around female vocals from folk bands and recording artists (Goldenhorse, Angus & Julia Stone, Ameliana Torrini; Tori Amos, Wendy Matthews, Camille) but -sometimes- the voice just sounds like it's coming through a megaphone, turning down the volume on the mids can help, sometimes. Turning up the main volume (on the PC and down on the following preamps and amps) has helped with dynamic range, but this current box upgrade proves to be a good opportunity to: get the mids and tweeter closer, have a better designed box, build a new box, and maybe bring some life to the woofers.
I'm open to suggestions, but it's not like I'm at a point where there's an obvious upgrade that can be made over an internet connection, most everybody I know in person watches TV with subtitles on and thinks that the only spec that matters on a soundsystem is how loud it can get. I have had people over for a listening session only to have them say "it's just clearer, so what?" I don't know anyone who knows anything about HiFi, or even cares for that matter, they tell me it's not real and that I'm making it up, when I show them the books I have on the topic they say "that still doesn't mean it's real", I have acoustic panelling in my room, but everyone who comes over and sees it thinks it's weird and talks like I must have seen it on an episode of Star Trek or something and thought it was real, even when I show them pictures of rooms with similar treatments they just tell me that the picture must be of something different because it doesn't look exactly the same, like I'm making a mock up of something that I can't possibly understand because they don't care for it.
But, yeah, I've started cheap, I have an old 5.1 Yamaha receiver ready to test with I guess, I saw it as an opportunity to get the most out of my system as far as upgrades are concerned, like you said, you have a cheap Pioneer amp and still find Speaker upgrades to be the most rewarding.
I had and enjoyed my Re/Sponse 8" woofers paired with a Behringer iNuke but I turned them into a smoke and sparkler machine after testing the current draw on the nobsound preamps, the Goldwoods matched the specs for replacements, but they just haven't sounded the same either, the Sabaj A8's I replaced the iNuke with are just so transparent they're funkillers, I'm not afraid of getting different woofers, but this is an unexpected interim upgrade from a different major upgrade I had in mind, but this idea seems to solve these problems right now.
My "crossover" is software based, it's a custom PC between the CD transport and the (four) DAC's, I currently wonder if the midrange issue I'm having comes from it's distance from the tweeter (pic related), where the aforementioned mh-audio calculator recommends a much closer vertical distance to avoid lobing, -5cm @3.5khz- centre to centre, less distance than the mid dome is to it's surround, let alone the basket's sizeable frame, then the (usual) flange around the tweeter, which suggests a close flat horizontal alignment would make for a better vertical response with minimal difference horizontally.
So far I've based my system choices around female vocals from folk bands and recording artists (Goldenhorse, Angus & Julia Stone, Ameliana Torrini; Tori Amos, Wendy Matthews, Camille) but -sometimes- the voice just sounds like it's coming through a megaphone, turning down the volume on the mids can help, sometimes. Turning up the main volume (on the PC and down on the following preamps and amps) has helped with dynamic range, but this current box upgrade proves to be a good opportunity to: get the mids and tweeter closer, have a better designed box, build a new box, and maybe bring some life to the woofers.
I'm open to suggestions, but it's not like I'm at a point where there's an obvious upgrade that can be made over an internet connection, most everybody I know in person watches TV with subtitles on and thinks that the only spec that matters on a soundsystem is how loud it can get. I have had people over for a listening session only to have them say "it's just clearer, so what?" I don't know anyone who knows anything about HiFi, or even cares for that matter, they tell me it's not real and that I'm making it up, when I show them the books I have on the topic they say "that still doesn't mean it's real", I have acoustic panelling in my room, but everyone who comes over and sees it thinks it's weird and talks like I must have seen it on an episode of Star Trek or something and thought it was real, even when I show them pictures of rooms with similar treatments they just tell me that the picture must be of something different because it doesn't look exactly the same, like I'm making a mock up of something that I can't possibly understand because they don't care for it.
You should go to a hifi show (Australian HiFi Show is at the end of the month) to meet more like-minded individuals. Hifi and especially DIY audio are definitely small and niche communities. I’m in the San Francisco Bay Area where there are a good number of us and most people I have over are scientists or engineers who can at least enjoy learning about it even if it’s not their thing.
Regarding your design: I’m having trouble visualizing how isobaric woofers could be combined with a quarter-wave tube design? Aren’t those mutually exclusive?
Also, your PC-based crossover and DAC setup sounds a bit complicated. Are you sure you are filtering the signal properly for each driver and attenuating the drivers appropriately? What xover frequencies/slopes/attenuation levels are you using?
Regarding center-to-center distance, while it is a good idea to minimize that, it is unlikely your only problem. With large center-to-center distance, you can usually still find some spot that sounds good, if you move your head around vertically so that it is equidistant to the drivers.
Regarding your design: I’m having trouble visualizing how isobaric woofers could be combined with a quarter-wave tube design? Aren’t those mutually exclusive?
Also, your PC-based crossover and DAC setup sounds a bit complicated. Are you sure you are filtering the signal properly for each driver and attenuating the drivers appropriately? What xover frequencies/slopes/attenuation levels are you using?
Regarding center-to-center distance, while it is a good idea to minimize that, it is unlikely your only problem. With large center-to-center distance, you can usually still find some spot that sounds good, if you move your head around vertically so that it is equidistant to the drivers.
A vented box by any other name is still basically a vented box. 😉 The baffled driver is acoustically coupled (tightly) to the driver being acted upon by the box's acoustics.
The HiFi show idea sounds good but three days twelve hours drive away in Sydney probably won't find me anyone in Brisbane.
Voigt's BiB design uses the Vas in it's calculations, personally I always questioned Dickasons conclusions based on the Sd, and either way, if making the enclosure twice as big would change the sound of a speaker, then halving the Vas can't not affect the sound, but mostly I just prefer the basket-on-the-outside look...
The PC is a Linux based dedicated machine I figured that this way I would have every crossover I'll ever need plus all of the streaming platforms the DAC's are four ASUS Essence STX II's with Burson V6 Classics, they're in a separate enclosure. The software is PaXoverRack, it seems to be doing a good job, the subwoofer is set to 53hz, the woofers don't have a HPF, the woofers to the mids are 300hz, the mids to the Vifa 19mm soft some Tweeter Is at 3.5khz, all are 3rd order Butterworth, there are options for higher order slopes (4th order LR, even an 8th is available now I think, I have to purge the updater, it's being a sook) but the LR4's just zone each driver, maybe if I sat down and properly aligned the drivers timing that zoning might go away, I have a microphone wired up and ready to go, but I just haven't had a rainy day with nothing to do.
As for the sound issue, it's weird, it's always the same for the same recordings, it's not intermittent, like one night I'll play it and the voice doesn't sound off and another night I will and it sounds fine, just some recordings sound like they have a megaphone effect added, and some recordings it sounds like there is the slightest delay between the left and the right -but only for the voice- which I've read is something that does get done to fill out the voice occasionally. I just don't think that Emiliana Torrini would add an effect like that, it makes more sense to me that there's some kind of interaction between the mids and the tweeter that's off, and horizontally mounting and time aligning them will help.
But yeah, I'm hoping that this project gives my woofers some characteristerics, maybe it'll help the mids, plus swapping the soft domes for a ribbon I have would be interesting.
Voigt's BiB design uses the Vas in it's calculations, personally I always questioned Dickasons conclusions based on the Sd, and either way, if making the enclosure twice as big would change the sound of a speaker, then halving the Vas can't not affect the sound, but mostly I just prefer the basket-on-the-outside look...
The PC is a Linux based dedicated machine I figured that this way I would have every crossover I'll ever need plus all of the streaming platforms the DAC's are four ASUS Essence STX II's with Burson V6 Classics, they're in a separate enclosure. The software is PaXoverRack, it seems to be doing a good job, the subwoofer is set to 53hz, the woofers don't have a HPF, the woofers to the mids are 300hz, the mids to the Vifa 19mm soft some Tweeter Is at 3.5khz, all are 3rd order Butterworth, there are options for higher order slopes (4th order LR, even an 8th is available now I think, I have to purge the updater, it's being a sook) but the LR4's just zone each driver, maybe if I sat down and properly aligned the drivers timing that zoning might go away, I have a microphone wired up and ready to go, but I just haven't had a rainy day with nothing to do.
As for the sound issue, it's weird, it's always the same for the same recordings, it's not intermittent, like one night I'll play it and the voice doesn't sound off and another night I will and it sounds fine, just some recordings sound like they have a megaphone effect added, and some recordings it sounds like there is the slightest delay between the left and the right -but only for the voice- which I've read is something that does get done to fill out the voice occasionally. I just don't think that Emiliana Torrini would add an effect like that, it makes more sense to me that there's some kind of interaction between the mids and the tweeter that's off, and horizontally mounting and time aligning them will help.
But yeah, I'm hoping that this project gives my woofers some characteristerics, maybe it'll help the mids, plus swapping the soft domes for a ribbon I have would be interesting.
Attachments
No, simply that the speaker changes and improvements will be orders of magnitude greater in effect than futzing around with the electronics.
Compared to what? Regardless, AkAbak is (was?) likely the best of those available to DIYers, but too steep a learning curve for some of us/me, so short of MJK's MathCAD? worksheets that I used back then, HR with all its relatively recent upgrades/enhancements is plenty good enough for me.
I originally bought the Goldwoods because they had matching specs to the original Re/Sponse woofers I was using, I'm not hearing anything wrong with them, they play beautifully, no noise, nothing is done poorly, I just remember finding two more of the original drivers in the garden shed, realizing that isobarically loading them to the existing drivers would halve the Vas, and have the new driver unit act as though the box was twice as big, it added timbre to bass strings, it was a positive difference but those (exact) woofers aren't around anymore, and the Goldwoods have good T/S numbers, after the Behringer blew up I replaced it with two Sabaj A8's, and what I'm hearing fits well with what people tell me to expect from an ICEpower amp, nothing bad, but just no character, I turn up the volume and it's exactly the same, just louder, it's as much a bad thing as it is a good thing I guess, I'm not afraid to spend the money (as you'll soon see) but I can't find anything from a more reputable manufacturer -even then I can't be sure that it will make a huge difference if the specs match- they all require a bigger box, and this 2m tall thing is two foot wide as it is (there's a pic above showing how).
The HiVi was because it just fit my requirements better than the Morel I was using, and HiVi are formerly Swan, I realized I could add the Morel to my existing setup instead of a future upgrade I'm not going to do anymore. And use some Vifas (I found in the garden shed that glorious day) Maybe the problems I'm having with it are from running it down too close to it's Fs (BW3@350, Fs is 300), I can get an 8th order slope on it, but still think what I'm getting is a lobing issue, I could just as easily live with it, make a 6l box behind it for a future upgrade to an Accuton C168-6-990 7" Ceramic Cone Midrange. Although cutting out the weird mount it needs won't be fun.
I can easily upgrade the Dayton Ribbon to a RAAL Original 140-15D Ribbon Tweeter with Amorphous Core, it'd be a relatively simple operation to make it fit.
But the woofers? I'm not sure... I can't really make the whole box with a future woofers upgrade in mind... I'm not really sure what I could do considering the current situation, I can find a 6.5" that goes up to 4Khz and skip the separate midrange altogether, but there's lots of complaints about the quality of the midrange in this style box, I could get a woofers with a lower Fs, but that just makes the box taller, and apparently I'm already extended down to 20hz, a lower Vas only makes the box slightly smaller, and as I've said previously, I'm all but completely sold on the look of baskets on the outside, so, yeah, those are my thoughts/reasons, RAAL, Accuton, Goldwoods...
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Interesting.
I was always curious about the PC series
Impressive for the price.
For people not familiar
They are a big cast frame woofer with large vented magnets
and the usual recipe for decent woofer / bumped plates
gold bindings, rubber surround etc etc
I would assume a Bass reflex with 2x woofers
and a D' appolito set up would be great.
likely a straight forward crossover design
to get everything to combine nicely with the mid.
I'll read back, missed what tweeter is used
3" Dome mid you mentioned looks like lots of fun
if using 2x mids the small size makes excellent
mounting potential
I was always curious about the PC series
Impressive for the price.
For people not familiar
They are a big cast frame woofer with large vented magnets
and the usual recipe for decent woofer / bumped plates
gold bindings, rubber surround etc etc
I would assume a Bass reflex with 2x woofers
and a D' appolito set up would be great.
likely a straight forward crossover design
to get everything to combine nicely with the mid.
I'll read back, missed what tweeter is used
3" Dome mid you mentioned looks like lots of fun
if using 2x mids the small size makes excellent
mounting potential
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Bradstone, I recommend that you start building and evaluating speaker after speaker and enjoy the rest of your life.
Amplifiers too...
Amplifiers too...
Time for an update I expect...
After fiddling and playing with the specs to make this unit fully upgradeable I now have pic attached, if it goes well it will give me years of upgradability.
I'm thinking of making the entire thing out of 33mm thick okoume benchtops, everything but the front pieces corners can be cut with enough precision at the hardware store. They have a live edge too, which I'll keep down the edge of the flare and the front of the base.
I'm still trying to figure out how I can put it together with entirely internal screws, I'm thinking that a good glue might have to do...
The latest design now has a 80L or so box on the side that will house the midrange upgrade with a Qtc of 0.61 and shows pretty good SPL and group delay models in http://www.loudspeakerdatabase.com 's closed box simulator, this also brings down the flare edge to the shape that seems to perform best with BiB designs.
I'm also wondering if the unit would perform well if I (eventually) upgraded the woofers with Rythmik FM8 drivers (and amps, obviously) but I have no way of knowing even where to begin computer modelling that as an idea...
But yeah, anyone have any thoughts?
Thankyou GM for the modelling, I'll look at it soon, I've had a bit on these last few days...
After fiddling and playing with the specs to make this unit fully upgradeable I now have pic attached, if it goes well it will give me years of upgradability.
I'm thinking of making the entire thing out of 33mm thick okoume benchtops, everything but the front pieces corners can be cut with enough precision at the hardware store. They have a live edge too, which I'll keep down the edge of the flare and the front of the base.
I'm still trying to figure out how I can put it together with entirely internal screws, I'm thinking that a good glue might have to do...
The latest design now has a 80L or so box on the side that will house the midrange upgrade with a Qtc of 0.61 and shows pretty good SPL and group delay models in http://www.loudspeakerdatabase.com 's closed box simulator, this also brings down the flare edge to the shape that seems to perform best with BiB designs.
I'm also wondering if the unit would perform well if I (eventually) upgraded the woofers with Rythmik FM8 drivers (and amps, obviously) but I have no way of knowing even where to begin computer modelling that as an idea...
But yeah, anyone have any thoughts?
Thankyou GM for the modelling, I'll look at it soon, I've had a bit on these last few days...
