Old bass bins

hifiside

I made these bass bins many years ago and i finally put some drivers in them. The drivers are 25yr old PMT’s. I payed $5 a pc for them. They’re nothing special but they work for low end bass bin speaker stands.
There 4 per cabinet iso-baric tuned around 35Hz.

6thplanet

10"?

hifiside

@6thplanet said:
10"?

Yes

hifiside

.

hifiside

Sorry thought I said that.

6thplanet

I like🤘🏼
...guess I should have looked at the T/S parameters....8.5" piston diameter🤦🏻‍♂️

tajanes

@hifiside said:
There 4 per cabinet iso-baric tuned around 35Hz.

While I understand the benefits of clamshell iso configurations, from the standpoint of having a driver's backside firing outwards are there disadvantages due to the motor structure? i.e. Actual less moving volume/displacement (vs the cone side of the driver) and distortion issues? Possibly the later may be a non-issue below 500Hz?

thx

hifiside

These are 100 Hz and down basically subwoofers and speaker stands I would not run an inverted woofer up to 500 Hz. These didn’t seem to make any type of noise through the pole piece in open air running test tone through them. I bought these woofers years ago just for the motors.

tajanes

Any chance you have run / can post freq sweeps thru say ~2x your Xover point (200 or higher) in addition to your impedance sweep above?

hifiside

I will be putting them in my IEC baffle and doing a frequency sweep, and then I’ll be doing that impedance sweep of the cabinet that they’re in now with four of them to make sure it’s tune where I wanted it to be.