My other thread on the THX SPL headroom has been useful; Dave S confirmed that the +20dB is to clipping, rather than to be sustained. So I've been playing it too safe with my power requirements; I need to allow the excursion (and amp power) to reach 105dB but the driver doesn't need to handle it continuously as I'd naively planned. Provided I take a realistic worst case on the crest factor then probably even the 10F would be enough 
Now, I've been modelling the 8ohm version of the ss 10F as that looks the smoothest/flattest, but they both look similar; is the 8ohm the one to go for or is there not much in it? At 15w I'm not struggling for amp voltage..
Cheers
Kev
Now, I've been modelling the 8ohm version of the ss 10F as that looks the smoothest/flattest, but they both look similar; is the 8ohm the one to go for or is there not much in it? At 15w I'm not struggling for amp voltage..
Cheers
Kev
Oh no.. I can see the circle starting all over again!
Cheers
kev
You do know which came first don't you? The CHICKEN!
Matching PHL mid range
Hi Kev,
The Beyma TPL / AMT high frequency driver matches the efficiency, speed and dynamics of the PHL Midrange...Nothing else this side of a compression driver and horn can keep up.
For bass... If you have the space for an open baffle try a Precision Devices PD 1550 in a VPL baffle ( pic attached) or if you cant manage 4 or 5 feet clear behind the speakers try a sealed 60 litre box with a Beyma 12SW1300Nd...both are great options.
Cheers
D.
Hi Kev,
The Beyma TPL / AMT high frequency driver matches the efficiency, speed and dynamics of the PHL Midrange...Nothing else this side of a compression driver and horn can keep up.
For bass... If you have the space for an open baffle try a Precision Devices PD 1550 in a VPL baffle ( pic attached) or if you cant manage 4 or 5 feet clear behind the speakers try a sealed 60 litre box with a Beyma 12SW1300Nd...both are great options.
Cheers
D.
Attachments
Greebster; everyone knows that eggs turn into chickens, so I've always struggled with the chicken-first argument. Logically, the egg must have been first created by fairies and left under a bush in the garden to hatch.
Derek, very nice looking speakers there! I must admit that I was thinking of something a bit more conventional for my first serious build, and as simple as possible to use in less than ideal room position, but maybe one day I could aspire to something like that....
Cheers
kev
Derek, very nice looking speakers there! I must admit that I was thinking of something a bit more conventional for my first serious build, and as simple as possible to use in less than ideal room position, but maybe one day I could aspire to something like that....
Cheers
kev
Simpler than they look...!
Hey Kev,
You are right, Keep It Simple to start and see how it works out, the open baffle speakers are actually easy to build, but take up too much room space....
The simplest and most flexible build to start out is 3 sealed boxes stacked on top of each other...
Bass - 60 litre sealed box for the Beyma 12 inch driver. 30Hz to 300Hz (ish)
Midrange - 4 to 6 litres sealed box for PHL 6 inch 1060 ( 350Hz crossover) or 8 inch 2540 ( 250Hz crossover)
Tweeter - Beyma TPL AMT driver in small sealed box.
Experiment with your active crossover slopes and points and your done!!
A few details worth including...
Fit good spikes to the bottom of the bass cabinet.
Use a 10mm thick sheet or coaster sized circles of Sorbothane to separate / isolate the mid cabinet from the bass and the tweeter from the mids.
Use Twaron internal fill for the midrange cabinet.
Move the mid / tweeter cabinets to align the acoustic centres of the drivers.
Later on you can experiment with the TPL, remove the back plate and make a tapered 2 litre box with Twaron stuffing... All good fun and rewarding sonically.
Separate sealed boxes are the easiest to design and build, also the modular approach allows you to mix and match and easily compare different drivers in the future.
Cheers
Derek.
Hey Kev,
You are right, Keep It Simple to start and see how it works out, the open baffle speakers are actually easy to build, but take up too much room space....
The simplest and most flexible build to start out is 3 sealed boxes stacked on top of each other...
Bass - 60 litre sealed box for the Beyma 12 inch driver. 30Hz to 300Hz (ish)
Midrange - 4 to 6 litres sealed box for PHL 6 inch 1060 ( 350Hz crossover) or 8 inch 2540 ( 250Hz crossover)
Tweeter - Beyma TPL AMT driver in small sealed box.
Experiment with your active crossover slopes and points and your done!!
A few details worth including...
Fit good spikes to the bottom of the bass cabinet.
Use a 10mm thick sheet or coaster sized circles of Sorbothane to separate / isolate the mid cabinet from the bass and the tweeter from the mids.
Use Twaron internal fill for the midrange cabinet.
Move the mid / tweeter cabinets to align the acoustic centres of the drivers.
Later on you can experiment with the TPL, remove the back plate and make a tapered 2 litre box with Twaron stuffing... All good fun and rewarding sonically.
Separate sealed boxes are the easiest to design and build, also the modular approach allows you to mix and match and easily compare different drivers in the future.
Cheers
Derek.
The choice of tweeter is obviously a very important one wrt your choice of mid. I would decide on that once the bass unit choice is established and then choose the mid to fill in the gap! A modern dome, crossed over at 2kHz or so, would expand your options up to 6.5" or so for the mid. The small flange SB dimple-dome tweeter looks like an excellent choice, but I haven't used it myself, or any other really modern dome, since I started using ribbons or magnetostats some years ago.
Thanks chaps! So many options...
Having looked around, I'm beginning to suspect that the Beyma/PHL combos may be a bit above my price range, but I'll certainly keep it in mind - my budget seems to increase every time I ask a question!
Toaster, I've been looking at tweeters this lunch time - there are millions! But there do seem to be some that will go to 2-2.5kHz reasonably comfortably. I'll probably post another thread on that when I've covered a bit more ground.
Cheers
Kev
Having looked around, I'm beginning to suspect that the Beyma/PHL combos may be a bit above my price range, but I'll certainly keep it in mind - my budget seems to increase every time I ask a question!
Toaster, I've been looking at tweeters this lunch time - there are millions! But there do seem to be some that will go to 2-2.5kHz reasonably comfortably. I'll probably post another thread on that when I've covered a bit more ground.
Cheers
Kev
As has been mentioned, the Audax midrange quality is wonderful for its prize.
From my experience, 3-way overall quality really depends on the woofer quality. I mean, if the mid-hi is so good, cheap woofer will tend to make things worse. Because you already decided on the woofer (yes, it is the most expensive than the rest of the drivers), using too-good midrange MIGHT become an issue when you want the woofer to perform as good as the mid.
Good point, I guess they all need to match up reasonably well or I'll be wasting money. I also have to remember that this is my first serious build - the weakest link could well be me!
Currently I think its likely to be either the F10 or one of the Audax units mentioned on this thread, although I'll want the system as a whole to hang together so the 'final' choices (for all the drivers) will probably be made at the same time.
Cheers
Kev
Currently I think its likely to be either the F10 or one of the Audax units mentioned on this thread, although I'll want the system as a whole to hang together so the 'final' choices (for all the drivers) will probably be made at the same time.
Cheers
Kev
Blimey, deeply impressive stuff there. But... all that thought and effort, yet inexplicably they have completely overlooked the fairies' contribution to the first egg..
Cheers
Kev
I've been continuing to investigate the scanspeak 10F and I'm finding all very positive stuff. So if this will marry with bass/tweeter options that I like, then it'll probably be the one for me, though with the Audax HM130C0 still up there in case it fits in better. Thanks for all the help
The F10 is rather smaller than I'd originally imagined; I'm thinking it should be crossed over a bit higher than my initial intentions. To keep things simple I'd like it reasonably flat to some distance outside the x-over ranges without any sort of clever compensation being needed.
Fs is 90hz and (in a sealed enclosure of Qtc 0.7) -3dB is around 180Hz, so 2-octaves above Fs or 1 octave above -3dB is about 360Hz. I'll be using 4th order active X-overs; would something like 360-400Hz seem like a comfortable lower crossover?
The upper X-over seems to be pretty flexible; the flat range is quite high, so its probably the off-axis deterioration that'll limit it for me. Possibly 4kHz at most, but ideally 3kHz seems reasonable?
Cheers
Kev
The F10 is rather smaller than I'd originally imagined; I'm thinking it should be crossed over a bit higher than my initial intentions. To keep things simple I'd like it reasonably flat to some distance outside the x-over ranges without any sort of clever compensation being needed.
Fs is 90hz and (in a sealed enclosure of Qtc 0.7) -3dB is around 180Hz, so 2-octaves above Fs or 1 octave above -3dB is about 360Hz. I'll be using 4th order active X-overs; would something like 360-400Hz seem like a comfortable lower crossover?
The upper X-over seems to be pretty flexible; the flat range is quite high, so its probably the off-axis deterioration that'll limit it for me. Possibly 4kHz at most, but ideally 3kHz seems reasonable?
Cheers
Kev
Seems reasonable enough, although it's OK here at 300Hz 24dB/8ve- it seemed comfortable playing louder than I would need it to! Ideally crossover low from the tweeter. The SB neo is not only very good- by reputation- but the small flange size reduces centre-to-centre distance so that you can experiment with a wide range of crossover frequencies, if you want to. Although I've not built using these, I have heard them in quite costly and excellent sounding complete speakers where they were clearly not a limiting factor. The HM130C0 is a good driver which I have used, but in my experience the 10F and the HM100Z0 are cleaner-sounding up top. I still think the '130 is a nice drive unit for a smallish two-way speaker though.
Thanks both, I think we're getting there! The 10F appears to be as flexible as I'd imagined (or more!), and so if I go for a tweeter that'll work from relatively low then it'll give me a lot of scope for adjustment - which is ideal for me as a newbie. Hopefully ditto for the bass.
I was looking at tweeters earlier. The SB acoustics SB26STCN (with the neo magnet and 72mm flange, so I think this is the one suggested?) seems well regarded and the chart looks very good off axis up to 15Khz - the 60degree line is quite impressive (though it does then plummet a bit to 20kHz). It has an Fs of 960Hz; their power rating had a 2.6kHz 2nd order filter, so with a 4th order crossover presumably it would go down to below 2.5kHz - the low end of the response chart looks fairly flat to <1kHz and the impedance has largely levelled out by 2kHz too.
The SEAS 27TFFC also caught my eye; Fs of just 550Hz and a suggested range from 2kHz, pretty flat and okay off axis, though not as good as the SB.
EDIT: Looking from the other end, the L26ROY is said to be good to 1kHz; I'd prefer to stay well under that and it seems to get a bit lumpy around 600Hz but if the 10F will go down to 300Hz then I reckon the L26 will go up to 400Hz or so fairly safely, so again a reasonable overlap to play with.
Cheers
Kev
I was looking at tweeters earlier. The SB acoustics SB26STCN (with the neo magnet and 72mm flange, so I think this is the one suggested?) seems well regarded and the chart looks very good off axis up to 15Khz - the 60degree line is quite impressive (though it does then plummet a bit to 20kHz). It has an Fs of 960Hz; their power rating had a 2.6kHz 2nd order filter, so with a 4th order crossover presumably it would go down to below 2.5kHz - the low end of the response chart looks fairly flat to <1kHz and the impedance has largely levelled out by 2kHz too.
The SEAS 27TFFC also caught my eye; Fs of just 550Hz and a suggested range from 2kHz, pretty flat and okay off axis, though not as good as the SB.
EDIT: Looking from the other end, the L26ROY is said to be good to 1kHz; I'd prefer to stay well under that and it seems to get a bit lumpy around 600Hz but if the 10F will go down to 300Hz then I reckon the L26 will go up to 400Hz or so fairly safely, so again a reasonable overlap to play with.
Cheers
Kev
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Hi Kev,
why not look at the Hiquphon tweeters, they're smaller than 1" and have wonderful dispersion. Can easily be crossed around 2,5kHz or maybe even lower. They have a very subjectively natural sound and you can listen for hours without fatigue (I'm normally very sensitive to that).
HIQUPHON dome tweeter OWI, OWII, OWIII, OW3, OW4
Response of the OW1 from Zaph:
why not look at the Hiquphon tweeters, they're smaller than 1" and have wonderful dispersion. Can easily be crossed around 2,5kHz or maybe even lower. They have a very subjectively natural sound and you can listen for hours without fatigue (I'm normally very sensitive to that).
HIQUPHON dome tweeter OWI, OWII, OWIII, OW3, OW4
Response of the OW1 from Zaph:
Sorry, I'm late to the party. I just came across these new little Eton mids and thought you might at least want to take a look at them.
Eton, 3-401/A8/Pr
They look exceptional. Price is for a matched pair.
Eton, 3-401/A8/Pr
They look exceptional. Price is for a matched pair.
Thanks Jonas, I'd not seen those before, but it looks like they ship to DIYers like me so I'll certainly give them a look. I can't see anything about off-axis or dispersion at the moment but its probably there somewhere.
Thanks also jReave, another one I hadn't seen. I'll check it out, and also whether I can get it here.
Cheers
kev
Thanks also jReave, another one I hadn't seen. I'll check it out, and also whether I can get it here.
Cheers
kev
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