MCM 8" 55-2421 Isobaric

[ODougbo]

Short story Srten, the folks that bought the sub just came from a Best buys, listened to everything they had. They heard the compact Iso box and wanted to take it home with them.
I didn't think you would get it, but do understand your post.

I really don't think it would work in a 1cf BR, do you?

[sreten]

Hi,

The short story is you don't get it. You have low tuned poorly designed
boomboxes and seem to like them and keep insisting that they are good.

They are not, that ISO box is design disaster area that could be greatly
improved upon. Yes I don't get convincing people they are on to a good
thing when I know there is actually a far better solution, and that I'm
fobbing them off with lazy, inappropriate, poor design. I don't care how
good you think it is. Designed properly it will be simply better.
And capable of 4 times the SPL at a cost of nothing.

So you've sold some people a nice looking box that looks like it should
work well but actually doesn't work half as well as it should or could.

Yes, I don't get it.

rgds, sreten.

[ODougbo]

Mr. Sreten,

Yeah, I'm miserable in my world without bass [NOT] But I'll tell you what...I'm a bachelor for the weekend, plenty of MDF on hand and extra woofers.
You have mentioned a double sided woofer(s) box a couple of times, that's not much to go on.
Are you saying a box similar:
1) What cf?
2) What tuning?
3) Woofers right and left sides, mag to mag?
4) Same long port?

[revboden]

I agree with Sreten, those want to be in very small boxes going isobaric is silly. I modeled four of them in a 1.3cf box tuned to 40hz, that would make a nice woofer if the HP was set to 60Hz. looks like that driver is made to be used in cars as the sealed design using two of them wants a box size ~.43cf for a Qtc of .587.

[ODougbo]

The ISO box was a line of several experiments, wasn't looking to save space.

I'll build a new double woofer HT box in a jiff (you know I will). I'll post pics and descriptions accurately.

I have no devotion to ISO.

[revboden]

This may be sacrilege...(i love BR) but I'm getting the best results with 2 of those in a sealed .6cf box with 500w and PEQ boost Fc=20Hz Q=.7 gain =6db.

edit: never mind, the motor can't handle that power... dang

sealed without boost is still better though

[ODougbo]

Well I never did try a sealed box.

[ODougbo]

Sure got quiet in here.

What happened to the Simon Cowell fellow?

I thought there was going to be some pearls of wisdom by now.

[sreten]

Originally Posted by ODougbo

I really don't think it would work in a 1cf BR, do you?

Hi,

All the indications are two parallel in a 1cuft box tuned to around
30Hz would work, not the opposite, but venting instead of using
PR's would be pretty tricky, Flare-it - Free Speaker Design Software

All the modelling is in Silly's sub thread, around 12L each tuned to around 33Hz.

Dayton Audio SD270-PR 10" Passive Radiator 295-494
could work, weighted to between 400 to 500 grams I recall
in Silly's thread, one per driver in 10L to 14L per driver.

0.6cuft with two of them sealed with Bass EQ would work.

Another option is 10L to 12L with two Dayton 8" PRs.

If you want a "pearl of wisdom" its this, they are designed for small
boxes, and using bigger boxes than optimum does not help, it hinders,
if you did the modelling you would quickly realise this is the case.

As I said initially there is utterly no point using them isobaric.

There is nothing SC related in my comments. If you post stuff saying
its great when its plainly not right, there is nothing nasty in saying so.

rgds, sreten.

[sreten]

Originally Posted by ODougbo

I really don't think it would work in a 1cf BR, do you?

Hi,

All the indications are two parallel in a 1cuft box tuned to around
30Hz would work, not the opposite, but venting instead of using
PR's would be pretty tricky, Flare-it - Free Speaker Design Software

All the modelling is in Silly's sub thread, around 12L each tuned to around 33Hz.

Dayton Audio SD270-PR 10" Passive Radiator 295-494
could work, weighted to between 400 to 500 grams I recall
in Silly's threads, one per driver in 10L to 14L per driver.

0.6cuft with two of them sealed with Bass EQ would work.

Another option is 10L to 12L with two Dayton 8" PRs.
That would be a killer small sub, for small satellites.

If you want a "pearl of wisdom" its this, they are designed for small
boxes, and using bigger boxes than optimum does not help, it hinders.

There is nothing SC related in my comments. If you post stuff saying
its great when its plainly not right, there is nothing nasty in saying so.

rgds, sreten.