What are my options: dedicated 2 ohm midbass to fill 8" hole

[Ge0]

Howdy all,

I am looking to replace my 2ohm 8" Bose midbasses in my latest car. This is trickier than it may seem. I am limited to a 3" mounting depth. The replacement driver also needs to have a high sensitivity which is preferably above 93dB 2.83V / 1M. I like my midbass strong and emphasized in my tuning. I will be running the driver with an amp that produces 75W at 4ohm and 120W at 2ohm. Thus the reason for the 2 ohm driver, more power to the speaker. Target freq range for the driver will be 80Hz to 300Hz using 24dB/octave crossovers. Trying to keep the cost about $250 per driver so please don't recommend Dynaudio Esotars. Ain't gonna happen.

My initial thought was to go with as big of a driver that will fit in the hole. However, I'm finding it difficult to find a 8" midbass that shallow. For instance, I wanted to use a Stevens Audio MB-8. But, it is 1/2" too deep. So, I'm willing to go down in size to find the right thing. For instance, the Stevens Audio MB-6 will just fit. But, that's the only other 2ohm driver that I know of. Some say Stereo Integrity made a 2 ohm version of their TM65 MKIII. However, that driver is being discontinued.

I talked to Nick from Stereo Integrity yesterday. Word is that he is running out of parts from his current inventory and looking to replace them with new stuff. Most interesting to me is a shallow 8" driver. However, with CV19 lock downs in place he can't make any progress on that now.

So, what else is out there? Do you think I would be happy stepping down in size and going with MB-6's?











Ge0

[Ge0]

I saw a Focal driver while browsing today. It's called the ISU 200. Anyone have experience with this?

Also, even though 4 ohm the Dynaudio MW172 looks like a possibility. It's sensitivity is up in the 90dB range 1W / 1M. However, I don't think a 75W amp channel is going to push this guy hard enough.

Then there are the ScanSpeak Revelator 18W's I've been eyeing up. Similar specs to the MW172...

Ge0

[mlekk]

Revelator for me

[Ge0]

Revelator for me

Agreed. I've used them in the past



Quite frankly I am surprised nothing new / better has come out in over 10 years.

Ge0

[mlekk]

They took it pretty far , but yeah "Ten Years Later"

[Jdunk54nl]

A couple of questions,

1) How much space is between the speaker and door card? Do you have space to use a spacer to bump it out a little more to increase your mounting depth?
2) Why are you hung up on the 75w vs 120w? You do realize this is going to be about 1.5-2db difference, it won't be audible. If it it was 150w, that would only be 3db difference, still not really audible.

[geolemon]

I just commented similarly on your build log thread, but here's what I'm seeing:
a) you have 1.75" from your door structure to your window regulator.
b) you have 1.75" from your door structure to the actual front of that Bose factory speaker
c) you measured some additional distance inside the door panel - not seeing that measurement here but I'd guess maybe another 1/4"? more? less?

So by my estimate, you have about 3.5" (plus whatever that additional clearance is) for an 8" sub, but that doesn't factor in the thickness of the front flange and suspension - so maybe (depending on that rear clearance) you are shopping for an 8" sub that has 3" mounting depth, and will be mounted to a 1.25" thick mounting ring?

I feel like that opens up your options a bit more than a 1.75" deep eight, although that is still limiting.

[JCsAudio]

Why don’t you use those BOSE drivers and just use your amplifier to drive them? With a little door sound deadening and sealing they might sound great. I did this with my stock Ford midwoofers with a 100 wpc amplifier and DSP and they sounded astonishingly great and were easy to tune too.

This may also work but it’s expensive. Ask Justin Zazzi about these. He works for Rockford and knows a lot about them. SkizeR also has experience with them. https://www.crutchfield.com/S-ODm5Sr...3-BMW-SUB.html

[Jdunk54nl]

Over budget but the illusion audio c8-w

[Ge0]

Why don’t you use those BOSE drivers and just use your amplifier to drive them? With a little door sound deadening and sealing they might sound great. I did this with my stock Ford midwoofers with a 100 wpc amplifier and DSP and they sounded astonishingly great and were easy to tune too.

This may also work but it’s expensive. Ask Justin Zazzi about these. He works for Rockford and knows a lot about them. SkizeR also has experience with them. https://www.crutchfield.com/S-ODm5Sr...3-BMW-SUB.html

The thought has crossed my mind. My only concern is limited excursion. I'll need a cone to move if I'm going to get serious midbass out of the driver.

It appears quite a few companies are making BMW replacement speakers. Why not VW, Audi, Porsche? Grr....

Ge0