Member
Joined 2009
Paid Member
Well there's a limit to the size of cab I can get past the entrance to my family home so some level of compromise is included in this project.
I've had a devil of a time with the staining, Birch is not easy and the gel stains have really odd colours. I've ended up staining it over and over because it just doesn't look right. Unfortunately, all my best intentions of using sample pieces to proof out the finishing didn't help because they were too small. Lesson for next time. This is my first attempt at staining so you can't ask too much !
Anyhow, I've done what I can. It's not a light finish, it's quite a rich colour. The photo is not that colour-accurate but it passed the WAF test.
I've had a devil of a time with the staining, Birch is not easy and the gel stains have really odd colours. I've ended up staining it over and over because it just doesn't look right. Unfortunately, all my best intentions of using sample pieces to proof out the finishing didn't help because they were too small. Lesson for next time. This is my first attempt at staining so you can't ask too much !
Anyhow, I've done what I can. It's not a light finish, it's quite a rich colour. The photo is not that colour-accurate but it passed the WAF test.
Attachments
Last edited:
Is it the size of the door opening that is the problem, or do you face the same problem as I do - my wife standing in the doorway with arms outspread, saying "you're not bringing that in here!"
(I'm watching with interest, as I have a set of 15 inch Altec 420 Bi-Flex drivers waiting for new boxes. They need a 13 cu ft sealed or 48 cu ft ported enclosure...)
FWIW, the early AlNiCo model was smooth as a baby's bottom, yet had plenty bass in a 19-20 ft^3 tower [AKA MLTL] tuned to Fs. This was back with vinyl, tubes though, but can't think of a good reason why it still wouldn't be a good alignment with later models if specs didn't change too much over time.
Really, one can make the argument that 13 ft^3 is plenty large enough for Fs tuning if you don't need any reproduction below 32 Hz.
GM
Am i wrong in thinking that below 30ish the room's acoustics play a significant role?
i get a horrible resonation at ~160Hz (E3) ... which means that bass notes (41Hz - E0) get drown out by their harmonics... and also means that other bass notes in the vicinity get attenuated horribly D: I say this as an example of how a room plays a very big role at bass reproduction and you can't consider only the driver's/cabinet's parameters
...wait... it needs a bigger box when ported ?
i get a horrible resonation at ~160Hz (E3) ... which means that bass notes (41Hz - E0) get drown out by their harmonics... and also means that other bass notes in the vicinity get attenuated horribly D: I say this as an example of how a room plays a very big role at bass reproduction and you can't consider only the driver's/cabinet's parameters
...wait... it needs a bigger box when ported ?
Big time in most rooms and why normally one wants either a low tuning and/or smaller cab if tuned higher when its location is near/at a wall or corner when keeping the box as small as practical is a primary performance goal.
Reflex alignments are about having more gain BW to a lower F3 than sealed and this requires more box efficiency [bigger].
GM
Reflex alignments are about having more gain BW to a lower F3 than sealed and this requires more box efficiency [bigger].
GM
Member
Joined 2009
Paid Member
Member
Joined 2009
Paid Member
Installing T-nuts for the driver. I'm going to use 1/4 inch bolts. Right now I don't have bolts that suit the driver flange properly, but I've found two local sources on the web that I can visit for something more suitable.
p.s. the fuzzy image in the background is an all tube Yugoslavian made radio waiting for me service it
p.s. the fuzzy image in the background is an all tube Yugoslavian made radio waiting for me service it
Attachments
Member
Joined 2009
Paid Member
Member
Joined 2009
Paid Member
Member
Joined 2009
Paid Member
Take a look at Allen-head cap screws. Use black oxide for black frames and stainless steel for polished aluminum frames.
Bob
Member
Joined 2009
Paid Member
can you have someone stand next to that in a picture for scale. it really doesn't look as massive as it is in that picture.
work looks really good tho.
That drawing looks good, but be careful of shouldered bolts. I sold a couple of cabinets with T-nuts on the back of a 3/4" baffle without drivers. The customer couldn't (??) find the 1" cap screws I specified and used 1.5" screws. The shoulders bottomed on the T-nuts, but he kept turning. The T-nuts happily stripped out the tangs and the baffle was ruined because there was now no way to get the screws back out. One reason I use screw inserts now instead of T-nuts. If the baffle is 3/4" (18mm, whatever) do not use anything longer than 1". 1" and shorter cap screws are threaded their entire length.
Bob
Member
Joined 2009
Paid Member
Thanks Norman ! Yes - I'm quite open to the idea that I won't install a back to this, and instead of it being a sealed cabinet it may become a Boffle. It's also a handy place to store old clothes and pyjamas
I'm not in favour of adding any additional drivers, this will be a purist speaker. I may be quite happy with the bass as it is. We'll see how it goes.
I am going to design and build a couple of amplifiers worthy of this speaker. One will be a triode amplifier based on some very nice ideas about the power supply, the other will be solid state based around an interesting device or two.
Bob - I destroyed a t-nut on the back already, I found that they aren't all that good quality and one of them had a bad thread. This is the first time I've used t-nuts and well, they're cheap, what else is there to say about them. Threaded inserts would be my recommendation for a future build. I changed my approach by checking the threads before I installed the last of them. The bad one I had was on the back of the cleat for the back panel and it soon ripped free of the wood. I had to hold it with some pliers to recover the bolt. Good thing is that I have access to both sides of the baffle and so there's no danger of permanent damage - I can cut out anything that gets stuck. I guess you'll be providing bolts if you ever sell an unfinished cabinet with t-nuts again to save the consequences.
Last edited:
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.