OK about the voltage sens, until you choose a mid and we know it Vsens we won't know which will be required.
About MTM vs MMT, there is some discussion about it in this review. This B&W is an example where it was avoided:
http://www.stereophile.com/floorloudspeakers/691bw800/
You can always lay them out as MTM and make one just a .5 driver for BSC, excursion reduction, and thermal handling - just another option.
Pete B.
About MTM vs MMT, there is some discussion about it in this review. This B&W is an example where it was avoided:
http://www.stereophile.com/floorloudspeakers/691bw800/
You can always lay them out as MTM and make one just a .5 driver for BSC, excursion reduction, and thermal handling - just another option.
Pete B.
PB2 said:
Exactly what I did with some 2 ways that were just too "forward" sounding to me. They were D'Apolito but I changed them to 2.5 way.... loads better, much more laid back, and no noticeable problems using the MTM arrangement.
Simon
G.Kleinschmidt said:
I don't have any experience with Visaton drivers, looks good on paper but that is data/marketing literature. Anyone else have experience with these tweeters?
What are some of the lines carried by your distributors?
PB2 said:
Hi Pete.
That B&W review is interesting! The mid-range drivers have adifferent upper frequency response to compensate for the lobing issues incured by the distance of the lower mid-range driver from the tweeter.
I guess I wouldn't have this problem with the tweeter position in my current tower proposal.
WRT to mid-range sensitivity and baffle step compensation - the 9" Scan-Speak bass driver has a 2.83V half space sensitivity of 83dB.
Two of these units in parallel gives me a half space 2.83V sensitivity of 89dB.
Assuming I cross over at 200Hz, with the now narrower cabinet, the baffle step gain will begin above the bass-mid crossover. Therefore I require a midrange driver with a 2.83V sensitivity of 89dB.
This can be simply rolled off to 83dB at the baffle step with a simple LPF/pad for full BSC.
A significant advantage I see with my slightly modified 3-way WMTMW tower is that the bass woofers are well off the floor.
Their centres are also close at 1/3 the crossover wavelength.
If there are not any serious issues with the slightly different/bunched up MTM in the middle, then I suppose it may be a workable solution??
Cheers,
Glen
PB2 said:
Just off the top of my head Vifa, Peerless, Morel, Scan-Speak, RAAL, Visaton.
No Seas distributer to the best of my knowledge unfortunately.
Cheers,
Glen
Well, theres the Peerless HDS Nomex...seems it measures well in all available sizes...they should be relatively cheap so you can spend some money on a RAAL ribbon 😀
does not aranmar (john woodhead in melb) stock seas??
Waaaay back I said I'd never heard a good fourway, and even tho I know you have gone off it anyway, I guess that it's not quite true now that I think of it.
Have never heard a good four way with all the drivers in a single box. But I have heard a good four way with a standard three way box and using distributed subs. Can take advantage in the low bass region using stuff as laid out in the harmon kardon papers, and of course Earl is always pushing the sonic advantages of a few randomly placed subs in the room.
Trouble is it would very well most likely need to be actively implemented (can allow for varying phase etc based on different differences to the lp) and maybe would not be as visually impressive as an all in one box solution.
want capable mids? look at some of the phl stuff. High sens and can really take some stick. available in aus.
Waaaay back I said I'd never heard a good fourway, and even tho I know you have gone off it anyway, I guess that it's not quite true now that I think of it.
Have never heard a good four way with all the drivers in a single box. But I have heard a good four way with a standard three way box and using distributed subs. Can take advantage in the low bass region using stuff as laid out in the harmon kardon papers, and of course Earl is always pushing the sonic advantages of a few randomly placed subs in the room.
Trouble is it would very well most likely need to be actively implemented (can allow for varying phase etc based on different differences to the lp) and maybe would not be as visually impressive as an all in one box solution.
want capable mids? look at some of the phl stuff. High sens and can really take some stick. available in aus.
I notice the full-range Panasonic is still avaliable (NOS I believe)
May be useful as an efficient midrange and somewhat cheaper than a PHL, probably more difficult to integratre cleanly with a 1inch tweeter though
http://cgi.ebay.com.au/ws/eBayISAPI...m=300252657709&ssPageName=STRK:MEWA:IT&ih=020
May be useful as an efficient midrange and somewhat cheaper than a PHL, probably more difficult to integratre cleanly with a 1inch tweeter though
http://cgi.ebay.com.au/ws/eBayISAPI...m=300252657709&ssPageName=STRK:MEWA:IT&ih=020
Hi Glen,
Plenty of parallel driver interaction here - at lower frequencies each fading out as necessary. 10"ers in series. 15" + 18" in parallel.
10" Fane 10-125, like Alpha 10"
8" Visaton B200
10"
15" Beyma SM115-N
18" Eminence DeltaPro-18A
Just a test bed - all on a piece of 6ft x 18" Contiboard, still no sides of any kind and already rocking with T-bass drive.
Click on image, then click on downloaded image as well.
The Vsaton B200 is in series with 68uF at present - like a mid/tweeter. Running almost like a fullrange driver, though with augmentation. Already really nice even without 'tuning'.
Cheers ....... Graham.
Plenty of parallel driver interaction here - at lower frequencies each fading out as necessary. 10"ers in series. 15" + 18" in parallel.
10" Fane 10-125, like Alpha 10"
8" Visaton B200
10"
15" Beyma SM115-N
18" Eminence DeltaPro-18A
Just a test bed - all on a piece of 6ft x 18" Contiboard, still no sides of any kind and already rocking with T-bass drive.
Click on image, then click on downloaded image as well.
The Vsaton B200 is in series with 68uF at present - like a mid/tweeter. Running almost like a fullrange driver, though with augmentation. Already really nice even without 'tuning'.
Cheers ....... Graham.
Attachments
G.Kleinschmidt said:
SimontY said:
Hi,
Series connection can (reportedly from high level testing) cause
instability in drivers at high excursion where those drivers are
better behaved in parallel, presumably those drivers having
some marginal stability issues (see klippel.de).
FWIW for midrange issues one driver with certain thermal
parameters can always be equivalent to 2 other drivers.
🙂/sreten.
G.Kleinschmidt said:
Hmmm........
Whilst I'm pretty sure you think you understand my posts you also
seem to be pretty good at taking umbrage at any that does not
seem to agree with you. Fine, there are plenty of threads here
where the people left are the one who agree with themselves.
How do I put this .........
You can take your new found pseudo-speaker expertise and
VD's cookbook and put them both wherever you find preferable.
Pandering to my interests ? My interests are intelligent design.
I'm pretty sure you do not understand the background to my
posts and your literal (mis)interpretations are your problem.
FWIW critical damping = Qboxsealed = 0.5 and is a complete
waste of time with a driver of Qts = 0.44. As is any alignment
of most drivers where Vbox is ~ > 1/2 Vas. This rules out the
Bessel alignment also, leaving the Butterworth maximally flat.
There are better (and worse) choices for the bass alignment.
Doing BSC with the bass drivers or midrange (if suitable) does not
make any difference, with two 83dB bass drivers the midrange
sensitivity is going to be 83dB to 85dB unless you go for line
level BSC.
Line level BSC completely changes driver choice in some respects.
The Scanspeak parameters are those of a subwoofer, and it will
not be difficult to find something on paper that performs similarly
in a similar sealed box.
The giveaway for an 8" driver is its Mms of 106g, = subwoofer.
http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=295-460
Is a good performer, in the same box volume it has slightly less
bass than the Scanspeak, which is to be expected as it has a
+ 4dB higher intrinsic sensitivity, and a marginally lower Qbox in
the same box volume as the Scanspeak. However Sd is higher
and importantly Vbox versus Vas ratios are somewhat better.
This ratio is important for low distortion at high excursion.
(A driver with better numbers ? needs to have lower sensitivity)
..... you do not like being told Morel tweeters do not have
a good reputation ? ..... Why not simply ask what does ?
The Seas 27TDFC seems a natural partner to the Seas mid.
If active BSC is to be used (easy enough in the feedback loop
of a line gain stage) then an active 2nd order high pass at an
arbitrary low frequency is possible, making the Q adjustable
from 0.7 to say around 2 combined with a box Q ~ 0.6 will
give an arbitrary -3dB point. Though in-room -6dB and -10dB
are usually more important factoring in room gain.
Maximally flat bass alignments usually are not the best choice,
though for smaller sealed boxes usually the best compromise.
TBH this thread has got to 18 pages and really does not contain
much beyond loudspeaker basics / and some misinformation.
Reached an MT/ MTM + stereo subwoofers albeit the latter are 2
ohms and not powered seperately, so they require serious c/o's.
The tower proposal for bass has some advantages in driving /
smoothing a rooms vertical mode and the first floor reflection
at a serious WAF cost. The mid array in the B&W is essentially
near 0.5 way and one way of doing mid BSC and avoiding
the lobing issues of an MTM, which FWIW are horizontally
challenged also if the tweeters are put to the side.
And a final note : by considering active BSC you are using up
around 6dB of the 6dB to 10dB headroom in the bass that
I mentioned in an earlier post. Will it still work ? yes it will ......
/sreten.Just deleted at least 3 posts as I dont know what to say 😕
I think I would aim fore a 94db sensitivity...I suppose you want to play loud from time to time, dont you
I think I would aim fore a 94db sensitivity...I suppose you want to play loud from time to time, dont you
tinitus said:Just deleted at least 3 posts as I dont know what to say 😕
I think I would aim fore a 94db sensitivity...I suppose you want to play loud from time to time, dont you
So why don't you adhere to your previous promise and take your trolling elsewhere?
This is just plain nonsense. Here on record for anyone to read, I have presented every idea for bashing and scrutiny and discarded many along the way after distilling any trying to make sense of a lot of plainly contradictory advice.
I clearly stated my lack of expertise and lack of experience in the field of speaker design in my very first post and again at least once throughout this thread. Unfortunately this is great open invitation for continuous ridicule from sufferers of little man syndrome.......
A very intelligent comment, thankyou. I think I can guess where at least one copy of VD’s cookbook is already stuck.
Wow, a fan of Michael Behe.
There have been many excellent contributions throughout this thread that I have learnt a great deal from, but very little of value has come from deciphering your generally conceited and poorly worded posts. Secondly, oh great one, I frankly could not care less about the background to your posts and I am not persuaded by appeals to ones own authority – which is not something anyone with something worthwhile to contribute has to resort to.
The futility of aiming for a closed box Q of 0.5 has already been discussed at length in this thread. I already argued against the claimed need of overly damped sealed box for bass drivers.
From what I have read critically damped means 0.707 in a sealed enclosure and is a perfectly acceptable target and this is what I have been discussing, and what has been used in every sealed box UniBox driver comparison I’ve posted.
I already know what the mid-range sensitivity will be ~83dB with full BSC (either done in the bass or mid-range). Read my post where I outlined this explicitly a page back.
Do you have a point?
I have already looked at this 10” driver (as well as its 12” big brother already discussed in this thread)
As you just stated, it does not have better bass performance in a sealed box as the Scan Speak unit (which is what I actually asked for), so just what is your point? So SD is higher. Who’d have guessed that for a larger diameter driver?
The T/S parameters for the 9” 23W/5447T00 Scan Speak unit are:
Fs – 20.5Hz
Re – 3.4
Qms – 4.7
Qes – 0.49
Sd – 232cm2
VAS – 43.5
For your selected 10” Dayton:
Fs – 26.2
Re – 3.3
Qms – 3.26
Qes – 0.51
Sd – 356.3cm2
VAS – 45
Volume and F3 calculation for a closed box Qtc of 0.707 with 0.3 ohms series resistance:
Scan-Speak 9”
Vbox – 27.1L
F3 – 34.69Hz
VAS/Vbox – 1.60
Dayton 10”
Vbox – 27.4L
F3 – 42.6Hz.
VAS/Vbox – 1.64
The Dayton with an F3 8Hz higher clearly does not match the Scan-Speak unit in bass response and lacking your transcendent arithmetic skills I fail to see how a VAS/Vbox ratio of 1.64 can be classified as “somewhat better” than 1.60.
As for the Vbox versus Vas ratio relation to distortion, I explicitly asked for advice on the closed box performance of the Scan Speak unit with its desirably low closed box f3 when I found it. Absolutely no one has mentioned anything about Vbox Vs Vas and excursion limitation.
I’m open to any coherent argument / explanation that may dissuade me from spending a significant amount of money on a less than perfect driver, but please forgive me for my habit thus far of ignoring conceited, unexplained dismissals from those that would rather accuse me of misinterpreting their allegedly valuable input.
No, I do not like thoughtless general dismissals. Did it even occur to you to perhaps ask which Morel tweeter I may have under consideration?
From those with experience worth noting and who seem to know what they are talking about I’ve read nothing but praise for the performance of the Morel Supreme series tweeters.
Such as at David Gatti’s Delta Design page here:
http://www.gattiweb.com/delta_design.html
There are a number of well regarded commercial speakers using them. Such as Image’s Revelation speaker (which mates the Morel unit with a Seas mid-range):
http://www.audionut.net/documents/ImageRevelationAudEnz.pdf.pdf
I am not considering full active BSC. I have not explicitly stated this but it should be obvious to anyone who has actually read what I have recently written.
I said that a non-ideal BSC implemented in the speaker could be smoothed out with active equalisation, which is required anyway to work around much greater sources of frequency response error incurred in the average listening room.
Irrelevant.
This thread was supposed to cover the basics, so what? Also, there is nothing “serious” about crossing over multiple 4-ohm woofers (as already put to rest way back towards the beginning of this thread).
TBH if the content of this thread is basic for your satisfaction, from my perspective at least, you are more than welcome to go elsewhere.
This is why I went back to a tower proposal after the issue had been addressed much more comprehensively and lucidly by dlr and Jack Hidley. You are not bringing anything new to the table.
Great, now you’re just pointlessly reiterating points already made in a few post between Pete B and I just a page or so back (posts 421 and 424).
The significantly improved vertical dispersion / lobing issues of the closely spaced mid-range drivers comes at a slight cost in horizontal dispersion/lobing. No free lunch. Anything else, besides the obvious?
Hi Glen,
You have gone to a great deal of trouble rebutting Sreten's post.
Don't be thinking that Sreten puts you in a position where you are obliged to reply in order to defend yourself.
Under diyAudio rules he is allowed to do this - as he did !
DiyAudio should be for questioning, helping and positive discussion, not for undermining behaviour, and certainly not for implying where things should be placed like infants in a playground.
Think of the time Sreten's post caused you to waste which could have been more usefully applied to your project. When I saw the nature of what he had written - * I didn't even waste the time necessary to read it *
Sometimes it is better to ignore unhelpful posts like that, as I will if such dialogue continues.
Woe betide us if we were to become obliged to satisfy the criterion of others. We learn more from following our own intuition, and investigatinging our own findings, than being brow beaten down anyone else's already trodden path.
So Glen, I look forwards to reading of your construction results, even if they are not my preferred 'cup of tea' !
Cheers ........ Graham.
You have gone to a great deal of trouble rebutting Sreten's post.
Don't be thinking that Sreten puts you in a position where you are obliged to reply in order to defend yourself.
Under diyAudio rules he is allowed to do this - as he did !
DiyAudio should be for questioning, helping and positive discussion, not for undermining behaviour, and certainly not for implying where things should be placed like infants in a playground.
Think of the time Sreten's post caused you to waste which could have been more usefully applied to your project. When I saw the nature of what he had written - * I didn't even waste the time necessary to read it *
Sometimes it is better to ignore unhelpful posts like that, as I will if such dialogue continues.
Woe betide us if we were to become obliged to satisfy the criterion of others. We learn more from following our own intuition, and investigatinging our own findings, than being brow beaten down anyone else's already trodden path.
So Glen, I look forwards to reading of your construction results, even if they are not my preferred 'cup of tea' !
Cheers ........ Graham.
Hmmm.......
I cannot be bothered to answer most of your "points".
They seem to be self-aggrandising at someone elses expense.
Interpreting posts in the worst possible light is tedious and hypocritical.
FWIW :
Critically damped (no transient overshoot) second order is Q=0.5.
Maximally flat group delay (i.e Bessel) second order is Q=0.58.
Maximally flat amplitude (i.e. Butterworth) second order is Q=0.707.
It is arguably not the best alignment for large speakers that go
deep if room gain is to be exploited, but what is "best" ? YMMV.
Vas = 2.12cuft = 59L, but this disagrees with the PDF.
In fact the PDF disagrees with nearly all of :
Which I used for the comparison, you could have tried pointing out
the numbers you have did not seem to agree with those I was using ....
Regarding Vas versus Vbox ratios, see :
http://klippel.de/pubs/Klippel papers/Loudspeaker Nonlinearities–Causes,Parameters,Symptoms_06.pdf
And draw your own conclusions regarding Vas versus Vbox.
/sreten.
I cannot be bothered to answer most of your "points".
They seem to be self-aggrandising at someone elses expense.
Interpreting posts in the worst possible light is tedious and hypocritical.
FWIW :
Critically damped (no transient overshoot) second order is Q=0.5.
Maximally flat group delay (i.e Bessel) second order is Q=0.58.
Maximally flat amplitude (i.e. Butterworth) second order is Q=0.707.
It is arguably not the best alignment for large speakers that go
deep if room gain is to be exploited, but what is "best" ? YMMV.
Vas = 2.12cuft = 59L, but this disagrees with the PDF.
In fact the PDF disagrees with nearly all of :
Which I used for the comparison, you could have tried pointing out
the numbers you have did not seem to agree with those I was using ....
Regarding Vas versus Vbox ratios, see :
http://klippel.de/pubs/Klippel papers/Loudspeaker Nonlinearities–Causes,Parameters,Symptoms_06.pdf
And draw your own conclusions regarding Vas versus Vbox.
/sreten.
Hi,
well I actually undertook the effort to read the whole thread.
And my resultant impression is, that at the end Glen will have a speaker he threw terribly effort and time and money at but it´ll be a baby only parents can love 😉
Maybe I´m belonging to the numb unintelligent part of this world who will never meet an alien (as Your motto implies), but my experience is that the key to a good design is that it fulfills the requirements.
Having read 18 pages I still can´t see any requirements than those few rather vague ones:
- it should show the ropes of a vastly oversized amp
- 4 way design
- 4k AU$ budget
You could choose between hundreds of different bass drivers, simulate 1.000s more with programs and data of uncertain reliabilty till you drop dead and still have not one good solution!
You´d clearly do Yourself a favour -and anybody trying to help You- if You´d write down clearly a roadmap with as precise as possible requirements of the intended product.
- size of the speakers
- placement in the room (which room?)
- dynamic range
- flexibility, ie. modularity
etc. etc. just to name very few points I´ve read nothing about yet!
You´re sailing in a nutshell through fog without a compass on a unknown sea towards an undiscovered coast behind the horizon listening to commands whispered out of the off. Good luck, but do You really expect to succeed?
just my 5 cent
jauu
Calvin
well I actually undertook the effort to read the whole thread.
And my resultant impression is, that at the end Glen will have a speaker he threw terribly effort and time and money at but it´ll be a baby only parents can love 😉
Maybe I´m belonging to the numb unintelligent part of this world who will never meet an alien (as Your motto implies), but my experience is that the key to a good design is that it fulfills the requirements.
Having read 18 pages I still can´t see any requirements than those few rather vague ones:
- it should show the ropes of a vastly oversized amp
- 4 way design
- 4k AU$ budget
You could choose between hundreds of different bass drivers, simulate 1.000s more with programs and data of uncertain reliabilty till you drop dead and still have not one good solution!
You´d clearly do Yourself a favour -and anybody trying to help You- if You´d write down clearly a roadmap with as precise as possible requirements of the intended product.
- size of the speakers
- placement in the room (which room?)
- dynamic range
- flexibility, ie. modularity
etc. etc. just to name very few points I´ve read nothing about yet!
You´re sailing in a nutshell through fog without a compass on a unknown sea towards an undiscovered coast behind the horizon listening to commands whispered out of the off. Good luck, but do You really expect to succeed?
just my 5 cent
jauu
Calvin
Graham Maynard said:
Hmmm.......
This is getting is somewhat offensive ......
And personal ...... But that is your bag, is it not ?
/sreten.
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