It's all very encouraging, and these little SEAS drivers are great value too.
My only outstanding conundrum (and this is just me chatting; you've helped me loads) is thinking about my placement, because in my current house they will be very close to the wall. Obviously I can just turn the bass down (since I'm going to do active) but I might play around with the idea of a drooping response to try and balance the room/boundary gain a little bit. In that sense the normal desired outcome of a flat response is not wanted, and I'm going to experiment with different drivers and port lengths to get a selection of different response profiles from the same cabinet.
Thanks again - I've learned loads.
My only outstanding conundrum (and this is just me chatting; you've helped me loads) is thinking about my placement, because in my current house they will be very close to the wall. Obviously I can just turn the bass down (since I'm going to do active) but I might play around with the idea of a drooping response to try and balance the room/boundary gain a little bit. In that sense the normal desired outcome of a flat response is not wanted, and I'm going to experiment with different drivers and port lengths to get a selection of different response profiles from the same cabinet.
Thanks again - I've learned loads.
Xki enclosure thread, ?
Hithere X:I Lost the thread for Xki enclosure thread here on DiyAudio. Could you repost a link. Even Gxxxx]le could not find it and the DiyAudio search gave me the blow torch & unrelated threads. ...regards and thanks, Michael
Hithere X:I Lost the thread for Xki enclosure thread here on DiyAudio. Could you repost a link. Even Gxxxx]le could not find it and the DiyAudio search gave me the blow torch & unrelated threads. ...regards and thanks, Michael
If you want, I can turn on back wall and floor reflections (tell me distance away from back wall and how high your driver is above the floor) and I can show you what it looks like. Ain't going to be pretty - lots of reflection dips, back wall bass gain is good as I did not turn on baffle step losses (about -5dB) so that will come out maybe even with wall and floor.
Basically it amounts to hard against the back wall - maybe a 4" gap. As you say, the baffle step will be pretty much not there, which is why I think the SPL will probably be ok and match-in with the Alpair on top with minimal level adjustment.
Driver centre will be 60cm above the floor, as my speakers sit on a low plinth.
In relation to the interest in a falling response I was looking at the Troels Gravesen 8008 Corner design which is for a near-wall placement, and he puts the bass speaker in a very large box to get a falling response to play against the rising response which he expects from room/boundary gain. 8008-CORNER
That's exactly the kind of alignment I saw when fooling around putting lower Q drivers into big enough boxes to allow for a good cross-section TL.
Two drivers I would like to model for an MLTL enclosure,
The JBL 2245H and the
Volt RV4564
They will be big
The JBL 2245H and the
Volt RV4564
They will be big
The "accidental" technique works well for smaller woofers, 3" or 4".
Those 18" subwoofers are a whole different game.
Also, the best performance comes from drivers with a Qts close to 0.5... Not saying other drivers won't work, but the best punch in a MLTL comes with mid Qts drivers.
There's a trend right now using big sub drivers in sealed enclosures, using EQ to bring them down. That would surely save you a lot of space ...
Those 18" subwoofers are a whole different game.
Also, the best performance comes from drivers with a Qts close to 0.5... Not saying other drivers won't work, but the best punch in a MLTL comes with mid Qts drivers.
There's a trend right now using big sub drivers in sealed enclosures, using EQ to bring them down. That would surely save you a lot of space ...
Two drivers I would like to model for an MLTL enclosure,
The JBL 2245H and the
Volt RV4564
They will be big
The A-MLTL method works best for moderate Qts drivers, and “mass loading” helps to bring the tuning lower in frequency when the Qts is moderate (>0.45 or so). Lower values like 0.31 are best with a specifically designed tapered TL - like those used on PMC monitors. That can really give an incredibly accurate and deep bass note with higher efficiency than a sealed enclosure. The adjustment of Th exorrect dampening is critical though for the best performance (controlled deep bass that is not a one-note wonder).
That Volt is a superb driver. I could take a crack at a design for you if you are interested.
Yes would be most interested to see how the Volt RV4564 models
a bigger version of the BB5? which uses the 15" Volt driver
The BB5 which uses the Volt RV3863 enclosure is about 430mm wide 1010mm High 790mm deep so I would imagine the 18" model will be somewhat larger which sounds fine!
So do you prefer the 15in 3863 or the 18in 4564? I don't think a straight MLTL is appropriate, but can make a folded tapered TL work I think. Something like this but huge.
Low-Cost PMC-inspired TL Monitor with DC130A and DC28F
Low-Cost PMC-inspired TL Monitor with DC130A and DC28F
The 18in 4564?
Definitely the 18in 4564
So do you prefer the 15in 3863 or the 18in 4564? I don't think a straight MLTL is appropriate, but can make a folded tapered TL work I think. Something like this but huge.
Low-Cost PMC-inspired TL Monitor with DC130A and DC28F
Definitely the 18in 4564
Last edited:
For a Coral 8F-60, a MLTL of the following dimensions could work:
42in high x 16in deep x 10in wide (all internal), mount driver 12in from top, 2in dia x 2in long vent 4in from bottom, stuff top third up to driver with polyfill. USe 1.2mH and 6.7ohm BSC to get 89dB sensitivity after baffle step. F6 is 42Hz.
42in high x 16in deep x 10in wide (all internal), mount driver 12in from top, 2in dia x 2in long vent 4in from bottom, stuff top third up to driver with polyfill. USe 1.2mH and 6.7ohm BSC to get 89dB sensitivity after baffle step. F6 is 42Hz.
Attachments
So do you prefer the 15in 3863 or the 18in 4564? I don't think a straight MLTL is appropriate, but can make a folded tapered TL work I think. Something like this but huge.
Low-Cost PMC-inspired TL Monitor with DC130A and DC28F
Hi,
Did you manage to have a play with the RV4564 18" Volt in a folded tapered TL?
Hi,
Can anyone here advise me to see if this design works in accidental mltl.
I have a 60cm length 8 inch diameter pipe with another 50 cm length 6 inch diameter pipe inside. The speaker port is about 25cm long and 2 inch in diameter . The speaker driver is SB acoustics midwoofer PFC 6.5" and will be placed on top.
The pipe inside a pipe hopefully hopefully should resemble folded MLTL. I am using this for a subwoofer. I know I should use sub drivers, but sometimes they are just too slow sounding so I am using a midwoofer instead.
Any advice on this design?
Thanks in advance.
Oon
Can anyone here advise me to see if this design works in accidental mltl.
I have a 60cm length 8 inch diameter pipe with another 50 cm length 6 inch diameter pipe inside. The speaker port is about 25cm long and 2 inch in diameter . The speaker driver is SB acoustics midwoofer PFC 6.5" and will be placed on top.
The pipe inside a pipe hopefully hopefully should resemble folded MLTL. I am using this for a subwoofer. I know I should use sub drivers, but sometimes they are just too slow sounding so I am using a midwoofer instead.
Any advice on this design?
Thanks in advance.
Oon
Attachments
Last edited: