WinISD graphs: how to read/use them

[Theli]

After spending time playing with winISD and searching around, I found that I really don't know what is more of a priority or which has more of an impact on the final sound of the design I'd be creating. What does the Max SPL tell me, is it or the SPL graph more important?Or neither? For example I have a few designs where one sub has better low end extension, but has a lower max SPL compared to a different design with less low end but plays louder. (everything else being equal) What I`m asking is, which design would be better to get a good bass?

[Bill Fitzpatrick]

Speaker design if more often than not, a tradeoff. It's all a matter of what's important to YOU.

For me, being able to play loudly without distortion is more important that the bottom octave. Anyway, room gain is going to provide increased low frequency response that does not show up on the ISD plots.

There are plenty of woofers that will provide good low end extension and high SPL. Increase what you are willing to spend, buy a more powerful amp or add additional woofers. Those are all options. In my setup I have 2 12" per channel in sealed enclosures with an F3 for 50Hz. My bass is nice and tight and there is plenty of it.

Where most people might have a sofa, two chairs and a coffee table in the living room, I have a love seat, speakers, TV and room treatment. I want a system that won't give up the ghost when playing at rock concert levels. Those are my priorities. You'll have your own set. Define those first.

[Vikash]

Originally posted by Theli
which design would be better to get a good bass?

As Bill implies, 'good' will mean different things to each of us so there's no straight answer to your question.

You need to know the approximate levels you listen to music, then the max SPL graph may help. I would say it's probably the least important however. I personally don't listen at ear shattering levels so low end is often more important to me. But then don't forget room gain as Bill mentions, and it's also pointless IMO to have low end extension with increased distortion - so this is where the excursion vs frequency graphs, port speed, and delay graphs will be useful. And lets's not forget the main one, a flat frequency response is generally accepted as better than a humpy one

[jjdche]

To answer your question...the 'Max SPL' plot tells you what the limits of the driver in that alignment are. The limits are either going to be the power handling limit or excursion limit depending on the driver and frequency. The 'SPL' plot tells you the spl with whatever power level you enter in the 'Signal' tab. Keep in mind that just because you put a certain wattage in doesn't mean the SPL levels in the plot are acheivable, it only tells you the theoretical SPL, refer to the Max SPL tab to see if the levels in your SPL plot are possible.

Of course there is room gain, amplifier transfer function, etc., but Win ISD does give you a good idea of what will happen.

[simon5]

Can I add room gain in WinISD to see what will be the frequency response when it'll be in a room?

[simon5]

Help ?

[Bill Fitzpatrick]

If you draw a straight line from 0db at 125Hz to +12db at 10Hz, that will approximate room gain - give or take.

[Theli]

Originally posted by Bill Fitzpatrick
If you draw a straight line from 0db at 125Hz to +12db at 10Hz, that will approximate room gain - give or take.

what about in a car ?

[Theli]

Originally posted by Bill Fitzpatrick
Speaker design if more often than not, a tradeoff. It's all a matter of what's important to YOU.

For me, being able to play loudly without distortion is more important that the bottom octave. Anyway, room gain is going to provide increased low frequency response that does not show up on the ISD plots.

There are plenty of woofers that will provide good low end extension and high SPL. Increase what you are willing to spend, buy a more powerful amp or add additional woofers. Those are all options. In my setup I have 2 12" per channel in sealed enclosures with an F3 for 50Hz. My bass is nice and tight and there is plenty of it.

Where most people might have a sofa, two chairs and a coffee table in the living room, I have a love seat, speakers, TV and room treatment. I want a system that won't give up the ghost when playing at rock concert levels. Those are my priorities. You'll have your own set. Define those first.

what I`m trying to do is go for the unobtrusive look...I like the "clean" uncluttered look to my home..so I'm looking for small.compact. besides all I have is a micro system, it doesnt play very loud, and it doesn't need too So I don't need huuuge bass

[Bill Fitzpatrick]

Originally posted by Theli


what about in a car ?

Sorry, I don't know anything about car systems.

Originally posted by Theli



what I`m trying to do is go for the unobtrusive look...I like the "clean" uncluttered look to my home..so I'm looking for small.compact. besides all I have is a micro system, it doesnt play very loud, and it doesn't need too So I don't need huuuge bass

Sorry, I don't know anything about tiny systems.