The drivers are cheap enough to purchase 4 and do a test alignment.......sort of a line array segment which should be a good representation of the on axis behavior.
You could also try a high-passed bass reflex tuning, using a big cap (500-1500 uF).
This allows useful and smooth integration of a low frequency ripple peak.
Here is an example:
Sica 3.5H1CS with Qts = 0.66 (measured here)
in 6 liter enclosure tuned to 50 Hz
red without series cap, black with series cap 1200 uF:
This allows useful and smooth integration of a low frequency ripple peak.
Here is an example:
Sica 3.5H1CS with Qts = 0.66 (measured here)
in 6 liter enclosure tuned to 50 Hz
red without series cap, black with series cap 1200 uF:
32 speakers with high Fs dont make bass regardless of what you do.
If sealed F3 is 120 Hz then that is all they got.
If sealed F3 is 120 Hz then that is all they got.
32 speakers have a lot of SPL capability and allow being pushed with linkwitz transform.
a closed speaker has a rolloff at about 12 dB/oct.
So at 30 Hz SPL is down 24 dB compared to 120 Hz.
but each doubling of driver number allows +6 dB SPL.
2 drivers + 6 dB
4 drivers +12 dB
8 drivers +18 dB
16 drivers + 24 dB
32 drivers + 30 dB
so in theory using 32 drivers allows double SPL at a F3 two octaves down, compared to a single driver.
Why argue, I know how SPL works.
More SPL with no bass.
Nothing but vertical cancelation of highend.
They are midrange speakers.
Use a woofer.
Take that 120 Hz and raise it to 300 Hz with baffle step.
port wont do a thing. The speaker Fs is to high.
That is how simple it is.
More SPL with no bass.
Nothing but vertical cancelation of highend.
They are midrange speakers.
Use a woofer.
Take that 120 Hz and raise it to 300 Hz with baffle step.
port wont do a thing. The speaker Fs is to high.
That is how simple it is.
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You do, others might not.
Edit: Maybe @wesayso can tell us about bass capability of his two towers line array speakers?
I ported a driver with 1.3 Qts once. It required a well stuffed vented box. Sealed, the 4" gave no bass. Vented, the peaking or ripple was about +6dB. Using the lighter polyfil (not premium) and completely stuffing the box with 6.25oz of fill in the 4.5 ltr box reduced the ripple to better levels.
It is -just a particular type.
Roger Russell's IDS 25 arrays & their many clones aren't renowned for a lack of LF, so assuming you pick the driver & numbers properly for the intended SPL & dynamic range at the listening position once equalised, I don't see any issue, other than potentially needing a sharp HP if vented to prevent over-excursion.
Roger Russell's IDS 25 arrays & their many clones aren't renowned for a lack of LF, so assuming you pick the driver & numbers properly for the intended SPL & dynamic range at the listening position once equalised, I don't see any issue, other than potentially needing a sharp HP if vented to prevent over-excursion.
Yeah, the way I understand it is that one of the great things about our brain is that if overloaded with enough plurality of ~ the same signal it sums it to a spacious singularity. Good thing or we'd never be able to enjoy any large ensemble.
Being that Fs can just be completely ignored.
Cool 32 midranges as a woofer.
Now you just need 2000 tweeters for the sub.
Why would I buy one proper tractor to pull a trailer.
I could just sync 32 Hondas instead.
Cool 32 midranges as a woofer.
Now you just need 2000 tweeters for the sub.
Why would I buy one proper tractor to pull a trailer.
I could just sync 32 Hondas instead.
Fs of the driver is 81hz and 2mm of xmax…….in a vented alignment, I can sim a safe F3 of 80hz and with 32 drivers, SPL would drive most folks out of the room…….i just worry about a sloppy impulse and peaking response
if I seal them, I can go with a larger enclosure for an f3 of 100hz…….this will require a subwoofer/bass module very closely located or as the system base.
Why not just run them sealed with a system Q of, say, 1.0 and EQ them to the desired LF cutoff if the distortion numbers are suitable (I do appreciate not everybody wants to or can run EQ, but if you can, it may be a viable solution). That's how most wideband arrays are run, so it certainly works, or can work with the right units for the system requirements.
When Qts is this high it implies that, if a VB is possible the box volume will be several times Vab.
I know of some practical alignments for higher Qts values that use an auxiliary (line level) highpass filter. Here is a link to the alignment table, from an article about these sorts of alignments by Rod Elliot:
https://sound-au.com/qb5align.htm#s24
For example, from the table:
Qts = 0.562
Vb = 2.37 * Vas
Second Order Active Highpass Filter Parameters: F = 0.975 * Fs, Q = 0.516
Result:
Fb = Fs
kp = 6.38 (see article for info)