tb46,
separating the subs would also loosing a nice 220cm wide bench! You can see some of the bench in the photo at post #39 and in a 3D picture at post #32
I really hope that drivers would come soon.. The weather has been too cold for skiing and snowmobile riding (today -29C in the morning) Blaah, some more sketching, modelling, simulating, ..and perhaps som more wine?
separating the subs would also loosing a nice 220cm wide bench! You can see some of the bench in the photo at post #39 and in a 3D picture at post #32
I really hope that drivers would come soon.. The weather has been too cold for skiing and snowmobile riding (today -29C in the morning) Blaah, some more sketching, modelling, simulating, ..and perhaps som more wine?
Last edited:
Ok, I mentioned turning boxes in message #49. It is easy but first I want to hear the ppsl. Check also version 2 in message #1
According to hunecke simulator, moving speakers sideways along the short wall doesn't change 40Hz hump at all. Listening while laying on the floor helps! Fortunately I have 2 extra small subs.
Too many iterations so far I guess
According to hunecke simulator, moving speakers sideways along the short wall doesn't change 40Hz hump at all. Listening while laying on the floor helps! Fortunately I have 2 extra small subs.
Too many iterations so far I guess
Last edited:
So far still waiting for drivers...
I learned how to bake a baffle in Hornresp. Here is what to expect in 1pi conditions at maximum excursion
spl
phase
wavefront simulation
I learned how to bake a baffle in Hornresp. Here is what to expect in 1pi conditions at maximum excursion
spl
phase
wavefront simulation
Attachments
I'm not sure of the phase shift but I guess it is the plemun - depth, width, height? I mus try to change parameters and see what happens.
Pi environment definitions Radiation Space in a Room
Pi environment definitions Radiation Space in a Room
Attachments
Love the dual function bench/sub.
Sorry to butt in....
Don't use MDF, go with 3/4 baltic birch or 3/4 marine grade plywood (11-13 ply).
If you want smooth, fast response be aware of your amps damping factor as that dictates how well it can stop and start the moving mass of the driver.
A properly constructed, sealed enclosure, will always yield best balance of spl and sq.
Especially for home theater.
With a ported enclosure, when you send signal to the driver below the tuned frequency, the driver no longer sees the box and it will over-excurd.
If your subs are 15's, what is the next largest woofer in your system?
Sorry to butt in....
Don't use MDF, go with 3/4 baltic birch or 3/4 marine grade plywood (11-13 ply).
If you want smooth, fast response be aware of your amps damping factor as that dictates how well it can stop and start the moving mass of the driver.
A properly constructed, sealed enclosure, will always yield best balance of spl and sq.
Especially for home theater.
With a ported enclosure, when you send signal to the driver below the tuned frequency, the driver no longer sees the box and it will over-excurd.
If your subs are 15's, what is the next largest woofer in your system?
dctech,
The cabs were made of 21mm spruce plywood and they are closed, the drivers are optimal for closed cabs. The slot cavity has some resonance properties.
Hypex DS2.0 has damping factor 500 - enough?
My other subs are 10" and 8" BR, F6 around 35Hz, commercial subs with plate-amps.
So far I'm still waiting for the drivers....
The cabs were made of 21mm spruce plywood and they are closed, the drivers are optimal for closed cabs. The slot cavity has some resonance properties.
Hypex DS2.0 has damping factor 500 - enough?
My other subs are 10" and 8" BR, F6 around 35Hz, commercial subs with plate-amps.
So far I'm still waiting for the drivers....
there is no way that the plenum is causing a full rotation in phase shift at 60hz.
I wouldn't use horn response to try to model it.
It is inappropriate for subs.
Let the arguements begin.
Do not worry, it will sound great.
High Efficiency Speaker Asylum
"Just completed a new experiment Push-Pull double 15" subwoofer. This is the best sounding subwoofer that I've ever heard after building sub cabinets for 33 yrs. Love it. Les Hudson "
"At the moment my friend is casting aside his $10,000.00 subwoofer in his theater room for this push-pull double 15"
Stop worrying about modeling it.
It will be fine.
I wouldn't use horn response to try to model it.
It is inappropriate for subs.
Let the arguements begin.
Do not worry, it will sound great.
High Efficiency Speaker Asylum
"Just completed a new experiment Push-Pull double 15" subwoofer. This is the best sounding subwoofer that I've ever heard after building sub cabinets for 33 yrs. Love it. Les Hudson "
"At the moment my friend is casting aside his $10,000.00 subwoofer in his theater room for this push-pull double 15"
Stop worrying about modeling it.
It will be fine.
Sounds like a great match, and nice work on the internal bracing.
That little room is gonna light up like a roman candle!
Always encourages me to see people take the DI part of DIY seriously.
Do It!
Cheers from Vancouver.
Bench sub almost finished!
A quick and dirty installation of two 15" Daytons was performed this weekend. The box was sealed wit E-profile window seal tape. The cover weighs ~40kg which is enough to stop vibrations for normal levels without screwing it. I installed the reverse driver from the inside of the box, this allowed a narrower slot, 110mm (4 3/8"). The plenum was stuffed with a pillow containing polyfill. A solid and airtight filler is needed for the finalized system. Drivers connected in series, other with inverted polarity.
The sound is "unnoticeable" ie. low distortion and low GD. Diffrent sounds and tonalities of basses and kick drums and recording setups/effects are easily noticed. Room modes at 45 - 90Hz are still a problem to be solved. A second sub on the opposing wall should help a lot. Low-end extension is limited by Hypes plate-amplifier's fixed cut-off filter at 12Hz/24dB
The Hypex DS2.0 has an easy job. The level is 9-10 o'clock, no eq, no phase shift, lowpass at 12-15 o'clock. I have connected the Hypex simultaneously to two different amplifiers a AV and a stereoamp by RCAs. The AV amp has Audyssey and selectable LFE Fq, I used 90Hz. The stereoamp feeds Hypex from pre-out's left channel without any filters. Besides measuring sessions, I tune level and xo by ear for each amplifier.
REW-measurements (Onkyo TX-NR509, Audyssey on) fed from desktop pc's headphone out which has some attenuation of lowest and highest Fq. Microhone miniDSP UMIK-1(calibrated).
A quick and dirty installation of two 15" Daytons was performed this weekend. The box was sealed wit E-profile window seal tape. The cover weighs ~40kg which is enough to stop vibrations for normal levels without screwing it. I installed the reverse driver from the inside of the box, this allowed a narrower slot, 110mm (4 3/8"). The plenum was stuffed with a pillow containing polyfill. A solid and airtight filler is needed for the finalized system. Drivers connected in series, other with inverted polarity.
The sound is "unnoticeable" ie. low distortion and low GD. Diffrent sounds and tonalities of basses and kick drums and recording setups/effects are easily noticed. Room modes at 45 - 90Hz are still a problem to be solved. A second sub on the opposing wall should help a lot. Low-end extension is limited by Hypes plate-amplifier's fixed cut-off filter at 12Hz/24dB
The Hypex DS2.0 has an easy job. The level is 9-10 o'clock, no eq, no phase shift, lowpass at 12-15 o'clock. I have connected the Hypex simultaneously to two different amplifiers a AV and a stereoamp by RCAs. The AV amp has Audyssey and selectable LFE Fq, I used 90Hz. The stereoamp feeds Hypex from pre-out's left channel without any filters. Besides measuring sessions, I tune level and xo by ear for each amplifier.
REW-measurements (Onkyo TX-NR509, Audyssey on) fed from desktop pc's headphone out which has some attenuation of lowest and highest Fq. Microhone miniDSP UMIK-1(calibrated).
Attachments
Last edited:
I show you more measurments of PPSL470 to show you how much the room, microphone position and amplifier setup mean to the measured amplitude response.
AW-7 Vincent is my closed box SEAS coaxials in stereo running fullrange and with the PPSL sub. The sub had it's Hypex plate-amp's xo and level adjusted to give some more "bottom"
The HT51 system is Onkyo TX-NR509 with same AW-7 front speakers (3) and Amphion Helium2 rear speakers (all set to small), and ppsl470 sub xo at 90Hz and Audyssey optimization run.
mor is: microphone in the middle of the room (140cm height)
ear is: microphone at my ears' position when listening on sofa
Measurements done wit REW, 300ms 1/3 smoothing
AW-7 Vincent is my closed box SEAS coaxials in stereo running fullrange and with the PPSL sub. The sub had it's Hypex plate-amp's xo and level adjusted to give some more "bottom"
The HT51 system is Onkyo TX-NR509 with same AW-7 front speakers (3) and Amphion Helium2 rear speakers (all set to small), and ppsl470 sub xo at 90Hz and Audyssey optimization run.
mor is: microphone in the middle of the room (140cm height)
ear is: microphone at my ears' position when listening on sofa
Measurements done wit REW, 300ms 1/3 smoothing
Attachments
Last edited:
PPSL470 with stereo and AV setups, measured with the microphone in the middle of the room (minimal room modes' effects)
decay waterfall and spectrum
RT
My room has a serious problem with 45Hz. I think I should open up the ceiling and put some insulation wool there and make it work like a resonator or bass trap
decay waterfall and spectrum
RT
My room has a serious problem with 45Hz. I think I should open up the ceiling and put some insulation wool there and make it work like a resonator or bass trap
Attachments
When I connected a second auxiliary subwoofer, the dipped area at 60- 100Hz was nicely filled. The aux-sub is situated in the middle of the room's long wall and on the bookself near the ceiling.
Measurement at ear's position with and without the 2nd sub.
Group delay of the PPSL at 300ms is ok to me...
Measurement at ear's position with and without the 2nd sub.
Group delay of the PPSL at 300ms is ok to me...
Attachments
Last edited:
New measurements - I moved the auxiliary sub to the opposing short wall but the response at listenig point was better the other way. New measurement of sidewall position with same xo and level settings in both subs.
I have noticed that when I run the Audyssey setup in Onkyo, it changes the subwoofer xo to 40Hz. This results in bad response because the room problems at 40-100Hz are not treated by several drivers putting out same signal from various positions. So I always change manually back to 90Hz after running Audyssey.
Now i can let the speakers sit where they are and just try to fiddle with xo, eq and level.
The 2ch setup must also get the split signal for 2 subs. It is easy to do with a RCA splitter connector.
I have noticed that when I run the Audyssey setup in Onkyo, it changes the subwoofer xo to 40Hz. This results in bad response because the room problems at 40-100Hz are not treated by several drivers putting out same signal from various positions. So I always change manually back to 90Hz after running Audyssey.
Now i can let the speakers sit where they are and just try to fiddle with xo, eq and level.
The 2ch setup must also get the split signal for 2 subs. It is easy to do with a RCA splitter connector.
Attachments
Last edited: