I definitely don't like the sound of "less than ideal"
Anybody want to comment on my aperiodic enclosure suggestion? I know this can be difficult (if not impossible) to model, but I've heard of people having great success with manually tuning the aperiodic "vent" using a SPL meter. However, how much smaller could you make the cabinet if you go aperiodic? I've read about the aperiodic approach here where it was suggested to simply make the box as small as possible. But does that mean you can successfully put e.g. the Morel driver I suggested before (which has a recommended sealed Vb of 81 liters) in e.g. a 10 liters aperiodic enclosure?
Aperiodic can certainly be used to bring the Q of a too small a sealed box down.
I would not thou make it as small as possibleif you actually have room. The Aperiodic TLs i built prodided a bit less than 14 litre per driver.
dave
Hi dave. Could you perhaps point me in the direction of some literature about the aperiodic approach? How did you go about "tuning" your aperiodic TLs?
To tune them I use a combination of measured impedance curves, and my ears.
Clik-Test can be used as well (sort of using your ears to optimize the impedance.
Not much has been done lit-wize on aperiodic boxes.
The early paper by Ted Jordan: http://p10hifi.net/planet10/TLS/downloads/TedJordanAperiodic.pdf
and
PEARL PR2
and look in the forum for the CSS 4.5L Aperiodic.
dave
Clik-Test can be used as well (sort of using your ears to optimize the impedance.
Not much has been done lit-wize on aperiodic boxes.
The early paper by Ted Jordan: http://p10hifi.net/planet10/TLS/downloads/TedJordanAperiodic.pdf
and
PEARL PR2
and look in the forum for the CSS 4.5L Aperiodic.
dave
Some more:
North Creek Music's new MAPD driver loading
Found a paper by Richard Small:
http://p10hifi.net/planet10/TLS/downloads/Richard-Small-Aperiodic.pdf
dave
North Creek Music's new MAPD driver loading
Found a paper by Richard Small:
http://p10hifi.net/planet10/TLS/downloads/Richard-Small-Aperiodic.pdf
dave
Yes, I don't think woofer prices in US/Canada and EU compare directly. I find e.g. the Scan-Speak 26W/8534G00 similarly priced to one of the Peerless drivers mentioned earlier and a bit (but not much more) expensive than the TB W6-1139.
One thing I wondered though... The Vd is an expression of how much air the woofer can move, Sd x Xmax, right? But is the Vd directly related to how deep and punchy bass you can achieve? I'm asking because the Morel woofer I mentioned before has a Vd of 104 cc while the Scan-Speak has more than the double at 210 cc. Nevertheless the two drivers give similar f3 when simulating in a sealed enclosure. How should I interpret this?
Initial testing of 830668 drivers
Initial results on a bass system using 2 10" Peerless 830668 woofers per side in a 190 liter cabinet (yeah, they're big muthas) are pretty good, definitely encouraging. The drivers have almost zero break in time and reach comfortable into the lower 20s (in-room) without consideration to room placement, yet. F3 is around 30hz, F10 seems to be a bit below 20hz - this is in-room response, YMMV. The bass system uses different crossover points for each driver: 100hz 1st order (for the lower bass driver) and 200hz 1st order (for the upper bass driver) with the intention of crossing into the FR driver at a point above 200hz. Predictably, there is a bit of a rise from 40hz to 70hz. Not objectionable, but there and pleasantly so.
No problem with dynamics. I mean REALLY no problem with dynamics for my listening preferences (classical music). Nothing is breathing hard at all.
And all this is without break in on the woofers.
The stuffing in the box will be adjusted to smooth the response, but it's really close without much work. The boxes are maybe 40% - 50% stuffed with Bonded Logic Ultra Touch R13 insulation, not really teased much. Gotta wair for break in before doing much.
I'm not currently using a Mark Audio driver for the FR, but even with a lesser fr driver the results are pretty good. I'm going to let the woofers break in for a couple of days and start real measurement and tweaking.
Considering the sensitivity of the driver I'm currently using, an Alpair 7.3 should work well with just a single cap for a crossover at about 400hz. The Alpair 10.2 should work crossed over a little lower with a 20 - 30 ohm resistor across the driver leads. YMMV. (Maybe a pair of Alpair 7.3s or 10.2s will magically appear on my doorstep for testing in this arrangement. )
Another pair of boxes have also been build for a single 830668 driver, but I'm not sure when I'll get to that.
Initial results on a bass system using 2 10" Peerless 830668 woofers per side in a 190 liter cabinet (yeah, they're big muthas) are pretty good, definitely encouraging. The drivers have almost zero break in time and reach comfortable into the lower 20s (in-room) without consideration to room placement, yet. F3 is around 30hz, F10 seems to be a bit below 20hz - this is in-room response, YMMV. The bass system uses different crossover points for each driver: 100hz 1st order (for the lower bass driver) and 200hz 1st order (for the upper bass driver) with the intention of crossing into the FR driver at a point above 200hz. Predictably, there is a bit of a rise from 40hz to 70hz. Not objectionable, but there and pleasantly so.
No problem with dynamics. I mean REALLY no problem with dynamics for my listening preferences (classical music). Nothing is breathing hard at all.
And all this is without break in on the woofers.
The stuffing in the box will be adjusted to smooth the response, but it's really close without much work. The boxes are maybe 40% - 50% stuffed with Bonded Logic Ultra Touch R13 insulation, not really teased much. Gotta wair for break in before doing much.
I'm not currently using a Mark Audio driver for the FR, but even with a lesser fr driver the results are pretty good. I'm going to let the woofers break in for a couple of days and start real measurement and tweaking.
Considering the sensitivity of the driver I'm currently using, an Alpair 7.3 should work well with just a single cap for a crossover at about 400hz. The Alpair 10.2 should work crossed over a little lower with a 20 - 30 ohm resistor across the driver leads. YMMV. (Maybe a pair of Alpair 7.3s or 10.2s will magically appear on my doorstep for testing in this arrangement.
)Another pair of boxes have also been build for a single 830668 driver, but I'm not sure when I'll get to that.
Thanks for the info and time Silver. I take it from your name than your a young fellow
Side note. I was at a friends house today who had a pair of 2.5ways with peerless HDS woofers. They were only 5 1/2" woofers and i was shocked at the bass response and this was in a 25' room. I can't imagine what a 10" peerless must be giving you.
Side note. I was at a friends house today who had a pair of 2.5ways with peerless HDS woofers. They were only 5 1/2" woofers and i was shocked at the bass response and this was in a 25' room. I can't imagine what a 10" peerless must be giving you.
Why, yes. I AM QUITE young. In geological terms.
And on that note, I'm probably kinda old school in some of my beliefs regarding woofers. My opinion (and please, no flame wars, it's only my opinion) is that the best "sounding" bass comes from large drivers whose cones only move a small amount rather than small drivers that move a larger amount, even out to exercise their Xmax.
But to each their own.
And on that note, I'm probably kinda old school in some of my beliefs regarding woofers. My opinion (and please, no flame wars, it's only my opinion) is that the best "sounding" bass comes from large drivers whose cones only move a small amount rather than small drivers that move a larger amount, even out to exercise their Xmax.
But to each their own.
Thanks for the info and time Silver. I take it from your name than your a young fellow
Side note. I was at a friends house today who had a pair of 2.5ways with peerless HDS woofers. They were only 5 1/2" woofers and i was shocked at the bass response and this was in a 25' room. I can't imagine what a 10" peerless must be giving you.
Buzz,
5" 1/2 or 5"1/4?
And I see at least 3 types of HDS (Aluminum, Ploy, GFC) - which one did you hear?
The attached pictures are of the bass system under test. The full range drivers are currently CSS FR125SRs which will be replaced, probably with Alpair 7.3s.
Even after 40 hours of break in, the woofers are still changing. Change for the better, but still changing.
Even after 40 hours of break in, the woofers are still changing. Change for the better, but still changing.
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