Hi,
I just don't get it.
You seem convinced infinite baffle and open baffle are the same thing.
They are not. The open baffle has baffle loss. This is a very real loss.
The driver moves the same amount it would on an infinite baffle but
you get much less output.
You can't just EQ the baffle loss back because baffle loss does not
reduce cone movement, when you EQ it back you run into serious
excursion limitations.
If an open baffle has 12dB loss at particular bass frequency this is
the same as reducing the excursion capability to a quarter, or to get
the same response as an infinite baffle you need 4 times the power
and a driver with 4 times the excursion capability.
"The Morel goes that low with no EQ" is a ridiculous statement,
"I would actually need to apply reductive EQ in the bass" farcical.
Its seems completely bizarre to me that at no point have you
mentioned the most important aspect of an open baffle, its size.
/sreten.
I just don't get it.
You seem convinced infinite baffle and open baffle are the same thing.
They are not. The open baffle has baffle loss. This is a very real loss.
The driver moves the same amount it would on an infinite baffle but
you get much less output.
You can't just EQ the baffle loss back because baffle loss does not
reduce cone movement, when you EQ it back you run into serious
excursion limitations.
If an open baffle has 12dB loss at particular bass frequency this is
the same as reducing the excursion capability to a quarter, or to get
the same response as an infinite baffle you need 4 times the power
and a driver with 4 times the excursion capability.
"The Morel goes that low with no EQ" is a ridiculous statement,
"I would actually need to apply reductive EQ in the bass" farcical.
Its seems completely bizarre to me that at no point have you
mentioned the most important aspect of an open baffle, its size.
/sreten.I modelled it as an infinite baffle with a 100000 litre enclosure. I filled in the size of the front baffle but I guess WinISD doesn't actually account for this?
How much baffle loss can one expect from different size baffles? Do you have any links or programs which can model it?
Sreten, did you know you come across as pretty arrogant / rude?
SPL, I dunno what is standard for different frequencies. It doesn't need to be huge as there will be a second driver but I like to listen pretty loud.
How much baffle loss can one expect from different size baffles? Do you have any links or programs which can model it?
Sreten, did you know you come across as pretty arrogant / rude?
SPL, I dunno what is standard for different frequencies. It doesn't need to be huge as there will be a second driver but I like to listen pretty loud.
Josephjcole,
I have been looking at the design and I think I may be able to swing a 15" if I could have a VERY minimal baffle...
That Knight-15 looks ideal but I am worried that as it is so cheap the quality will be pretty pants in the midrange. Does anyone know of a driver with similar T/S spec that is perhaps a bit 'higher class' ?
Not that I have heard it, but at $65 it can't sound that good, right? It really does look good though.
I have been looking at the design and I think I may be able to swing a 15" if I could have a VERY minimal baffle...
That Knight-15 looks ideal but I am worried that as it is so cheap the quality will be pretty pants in the midrange. Does anyone know of a driver with similar T/S spec that is perhaps a bit 'higher class' ?
Not that I have heard it, but at $65 it can't sound that good, right? It really does look good though.
Tenson said:
Tenson,
He may have, but he was trying to help. Infinite baffle modelling can work to determine what sort of cone excursion you're going to get at a certain frequency (and input power) compered with an open baffle, but that's about all. The sound produced by the rear-wave from the speaker is effectively gone in an infinite baffle, whereas in an open baffle it 'sneaks' around the sides of your open baffle and interferes with the sound being produced from the front. Read Linkwitz (http://www.linkwitzlab.com/frontiers.htm), there's a lot of useful info there.
I think there's at least one piece of software on the FRD Consortium page (http://www.pvconsultants.com/audio/frdgroup.htm), but I haven't used it. I'm from that unfortunate group who prefers sealed boxed (closed mind
?).Cloth Ears said:
Tenson,
He may have, but he was trying to help. Infinite baffle modelling can work to determine what sort of cone excursion you're going to get at a certain frequency (and input power) compered with an open baffle, but that's about all. The sound produced by the rear-wave from the speaker is effectively gone in an infinite baffle, whereas in an open baffle it 'sneaks' around the sides of your open baffle and interferes with the sound being produced from the front. Read Linkwitz (http://www.linkwitzlab.com/frontiers.htm), there's a lot of useful info there.
I think there's at least one piece of software on the FRD Consortium page (http://www.pvconsultants.com/audio/frdgroup.htm), but I haven't used it. I'm from that unfortunate group who prefers sealed boxed (closed mind
Thanks, I realise Serten was trying to help but it just didn't and it got under my skin!
I had been looking around Linkwitzlab but found it a bit hard to find what I wanted! That looks like a very in depth write up.
I realise the sound 'sneaks round' hence why you get the nulls at the sides but if you listen on-axis I would have thought it would be the same as an infinite baffle with a large rear chamber. Obviously that is not quite the case though?
What do you prefer the sealed box's for? Mid-range or bass? Or everything?
No. Actually, off to the side of an open baffle, you get cancellation at all frequencies, because you are equidistant from two equal (not really) signals exactly out-of-phase.Tenson said:
But on-axis you still get cancellation at low frequencies.
Here is a table of required baffle size for a given frequency:
http://melhuish.org/audio/baffle.html
This table does not take into account room gain, fold-back sections, etc. For more detail, there is an Excel spreadsheet that takes more variables into account. DL it from:
http://melhuish.org/audio/software.html
Finally, a great woofer for open baffle would be the Dayton 15" OB subwoofer, from partsexpress.
Tenson said:
I realized that. We've been having this 'discussion' on another forum - IMO it's because you can't see the other peoples faces that you can't ever seem to get across what you want to say without ever causing offence to someone. It happens with email also, which is why I think it's a face (or body language - and lack thereof) issue.
I figure that I'll stuff up every now and again (you might even take offence at my lecturing
) and just end up doing a "whoops, sorry" post after...Tenson said:
For my-self, I'm going sealed at present, although my reference speakers are a pair of Elac b/r's (510's, I think). The bass bins are built, the tweeter and upper mid both come as individual sealed units anyway, and I think I'll match the lower mid to the rest.
But, don't give up on the open baffle, as the initial design is as simple as getting your speaker and cutting one hole to put it in. I've even seen initial ideas done on cardboard (in this forum). Well worth it to try, if you like the sound. don't listen to an old buggar like me
!Cloth Ears said:
Usually, I don't! These (if I get through the design stage!) will be more than a tad differnt than anything else out there though. I doubt they will fit in my room however lol! First DIY project- build a new house!
I have been working with T on the things and I think we are finally starting to get somewhere with driver choice.
Tenson said:
Well the price is certainly not the best way to determine the sound quality as there are quite a few good sounding cheapish drivers out there. I've never heard it but it does look like it might work for your needs. No way to really know what it would sound like without listening though. Build quality looks decent though, especially for the price.
Joe
Tenson said:
Hi,
I'm sure I do in some cases, to some people.
Usually when I'm trying to draw attention to the fact
the thread makes no sense to me at all, and some
reasoning somewhere is desperately wrong.
Seems to me the only polite way of doing it is going off,
doing all the reading, come back with the references
and explaining the whole thing, this takes time.
And a lot of the time I simply can't be bothered to do this,
so I just say somethings wrong, and one good reason why.
/sreten.Arrogant ?
Hello Tenson!
Here would be something to experiment with, much cheaper than PHY, Klangfilm, etc.
http://cgi.ebay.de/PHILIPS-Breitban...99502324QQcategoryZ113418QQrdZ1QQcmdZViewItem
Here would be something to experiment with, much cheaper than PHY, Klangfilm, etc.
http://cgi.ebay.de/PHILIPS-Breitban...99502324QQcategoryZ113418QQrdZ1QQcmdZViewItem
If I may come in from the side here, may I ask why you specifically want a two-way? Why not a three-way with a dedicated bass. That frees up a lot of good drivers that can be used as midrange drivers on the OB, and places less stress on the choice of bass driver.
Going down this route, you could use a simple 1st-order XO at 80Hz - 100Hz from a bass to a mid. Take a look at my suggestions for an OB speaker in the thread called 'The under $100 challenge'. Take for example the 'Highest Cost (and performance) design' idea. The driver's total cost will be only US$121.78 (excluding shipping). The bass will go down to +/- 108dB @ 40Hz and +/- 105dB @ 35Hz. It is down to about +/- 100dB @ 30Hz. This will be a relatively cheap intro into the world of OB, and then when you have gotten your feet wet, you can then plan to go from there. There are a lot of drivers that are much better than the one's I chose to use, but this will give you a good idea of what to expect, and it won't cost the earth.
My personal vote for a very good OB system would be a system idea that Thorsten described a while back. A 21" driver in a LT cab as the sub-bass driver (below 30Hz), another 21" as the OB bass (30Hz to +/- 80Hz), a good mid or full-range (Thorsten likes the Supravox IIRC), and, if needed, a tweeter (preferably a ribbon). Very big, but it could prove to be unbeatable.
Enjoy,
Deon
Going down this route, you could use a simple 1st-order XO at 80Hz - 100Hz from a bass to a mid. Take a look at my suggestions for an OB speaker in the thread called 'The under $100 challenge'. Take for example the 'Highest Cost (and performance) design' idea. The driver's total cost will be only US$121.78 (excluding shipping). The bass will go down to +/- 108dB @ 40Hz and +/- 105dB @ 35Hz. It is down to about +/- 100dB @ 30Hz. This will be a relatively cheap intro into the world of OB, and then when you have gotten your feet wet, you can then plan to go from there. There are a lot of drivers that are much better than the one's I chose to use, but this will give you a good idea of what to expect, and it won't cost the earth.
My personal vote for a very good OB system would be a system idea that Thorsten described a while back. A 21" driver in a LT cab as the sub-bass driver (below 30Hz), another 21" as the OB bass (30Hz to +/- 80Hz), a good mid or full-range (Thorsten likes the Supravox IIRC), and, if needed, a tweeter (preferably a ribbon). Very big, but it could prove to be unbeatable.
Enjoy,
Deon
Deon,
What I am doing (and Thorsten is heavily involved lol!) is not far from that but with a few things which make it even more un-beatable. No worries though I think I have found what I need drivers wise. I could go for a separate bass and mid driver in open baffle but I really want to go co-axial for this so it is just not practical.
What I am doing (and Thorsten is heavily involved lol!) is not far from that but with a few things which make it even more un-beatable. No worries though I think I have found what I need drivers wise. I could go for a separate bass and mid driver in open baffle but I really want to go co-axial for this so it is just not practical.
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