Dotd

[cooper]

Love the Q8. A very versatile little sub. Like the TB W-6 also, but for 50 clams, I'd take the Quatro. Just my 2 cents.

[Wolf]

Re: Dotd

Love the Q8. A very versatile little sub. Like the TB W-6 also, but for 50 clams, I'd take the Quatro. Just my 2 cents.

I'll be using it with the 70W plate and the SD270-PR soon in 1ft^3 for the 'Tesseract' project.

As soon as the 'Attitudes' are completed...
Later,
Wolf

[robwest]

Re: Dotd

Just curious why you would choose those over these: http://www.mcmelectronics.com/produc...-2421-/55-2421 ?

[Wolf]

Re: Dotd

Just curious why you would choose those over these: http://www.mcmelectronics.com/produc...-2421-/55-2421 ?

Q8 has more Xmax, more sensitivity, more power handling, rubber surround (not foam), and is lighter in total mass were it to be used in a car or home for easier relocation.

To top it off- it's from PE with a 5 year warranty!

Sounds good enough to me to justify the price.
Later,
Wolf

[robwest]

Re: Dotd

Actually, check the specs again.
X-max of 16mm to 9.5mm
87db to 86.2.
Foam v/s rubber. Can't argue with the longevity of the rubber.
Once set up, is re-location that big of an issue to where a pound (13oz) will make that big a difference?

On second look we've got 3 different voltages for the sensitivity...hard to know exactly, but I'd say they are pretty much even.

[Wolf]

Re: Dotd

Actually, check the specs again.
X-max of 16mm to 9.5mm
87db to 86.2.
Foam v/s rubber. Can't argue with the longevity of the rubber.
Once set up, is re-location that big of an issue to where a pound (13oz) will make that big a difference?

I don't know where you're looking.
Q8:
89.2dB Sensitivity at 2.83V (2W, so it might be less output than the MCM)
9.5mm Xmax.

The MCM has:
87dB and 8mm Xmax at one watt.

All Xmax from Dayton are one-way spec, and most DIY drivers are one-way spec.
Later,
Wolf

[robwest]

Re: Dotd

I don't see anything on the Dayton spec sheet that says it is one way- but I do for the MCM 16mm.

I like the Fs of 29.1 better than 42.4 as well.

[Wolf]

Re: Dotd

It shouldn't have to. The 'assumed' spec is one-way in almost all cases.

Depending on being overhung or underhung, the definition of Xmax as an equation:
Xmax (over) = (coil length - gap height)/2
Xmax (under) = (gap height - coil length)/2

Later,
Wolf

[robwest]

Re: Dotd

Cool, I see those listed for the MCM, but not for the Dayton.

[Wolf]

Re: Dotd

That doesn't mean it's not the actual Xmax figure if the motor dimensions are not listed. The Xmax figure is enough data.
Are you trying to disprove the capabilities of a Dayton driver or something?
I don't understand your beef with it. It's a solid piece, and does a lot of things right.
Later,
Wolf

PS- don't use the Q8 in a sealed box. I don't care what the specs say- it no likey!

[robwest]

Re: Dotd

Actually, I'm just trying to learn why one driver is chosen over the other. Price isn't everything; high or low. On the face of what I see, it seems that the MCM only falls short in Vb requirement and power handling. And it excels in Fs, usable F range and price.

[Wolf]

Re: Dotd

Actually, I'm just trying to learn why one driver is chosen over the other. Price isn't everything; high or low. On the face of what I see, it seems that the MCM only falls short in Vb requirement and power handling. And it excels in Fs, usable F range and price.

Usable freq range is not usually a good parameter to follow. It's just a best guess by the person writing copy for the product.
As to volume requirement, if you are referring to the Vas spec, that is not what that means.

From PE at http://www.parts-express.com/resourc...ding-terms.cfm

Vas: The Thiele-Small parameter that measures the overall compliance of a loudspeaker transducer. The Vas is defined as the volume of air that has the same compliance as the driver.

They are very different things, and you don't have to use that volume as a minimum at all, and can use less/more than that a lot of times.

As to the Vd, it's typically the volume of displacement that the driver is either capable of or occupying. I've seen it used in both cases. To that end, I don't know what would be 203 ltrs in relation to either of those for the Q8.

In a lot of cases, you can tune below Fs, and still get decent response extension, so it varies with different drivers whether Fs is even a good indication of extension or not.
HTH,
Wolf

[robwest]

Re: Dotd

It does seem they are evenly matched. It'd be interesting to see them compared in similar boxes with the same x-over. And really interesting to see 2 of the MCMs v/s 1 of the Daytons as a price/performance comparison.

Thanks for the info!

[Wolf]

Re: Dotd

It does seem they are evenly matched. It'd be interesting to see them compared in similar boxes with the same x-over. And really interesting to see 2 of the MCMs v/s 1 of the Daytons as a price/performance comparison.

Thanks for the info!

The MCM is an older driver too. It's been out for a long time.
Glad I could help,
Wolf

[depthsounder]

Re: Dotd

The MCM has abnormally low q parameters; combine that with a low Vas and it makes it really hard to work with. You want to put it in a ported box, but the ports end up being way too long for the small box it requires.

It's an odd one, that MCM.

The Dayton is a little easier to work with, I used two IB in a car stereo install back in the day (when it was a lot lower in price). It sounded great with 50W per driver.

-David