How much do "specific" drivers matter??

burdette

I built a center channel speaker using the crossover from a Polk RTA 8T acquired from Russman. The 8T utilizes an SL2000 and two 6510 6.5" drivers. I tried to duplicate the interior volume of the 8T, but substituted 6502 drivers for the 6510s because 6502s were what I had. I was pretty happy with the results, but noticed a bit.. just a bit... of boominess in the midrange compared to my Monitor 7Cs. I chalked it up to having not quite the right cabinet volume. However, HBombToo gave me his 'old' 6510 drivers yesterday and I attached bucking magnets and replaced the 6502s I'd been using.

The boominess is gone. HBomb commented that he liked my center.. using the 6502s... but it is now even better than it was. Whatever the "minor" differences between the two Polk drivers, the difference was enough that I easily heard the improvement from using the drivers for which the crossover was designed.

We've discussed here before how important a crossover is, and how is is designed for *specific* drivers. I now have first-hand sonic experience of this truth. I don't know how much difference I would have heard - if any - between the original SL2000 (classic clear Silver Dome) and the 'new' one, with the black dome. I replaced the black SL2000 with an 'old' clear one at the same time I changed out the 6.5inchers. But overall, I can clearly.. clear being the important word - hear the difference between what I had and what I have.

I could have and would have defended previously the fact that a crossover is designed for SPECIFIC drivers.. thus the problem in buying an off-the-shelf crossover. I now have first-hand, in-my-system, experience of this fact.

A substitute driver may serve, it may get you by, as the 6502s did for me. But don't ever underestimate the importance of the crossover as part of the overall "system" that is a loudspeaker.

Tour2ma

Thanks for sharing...

Fastmerc

Burdette,

Interesting conclusion, you mentioned the volume of the enclosure as well. Do you think theres a chance that had more to do with it? How do the Vas specs compare on those different drivers? Another interesting experiment would be to build an enclosure designed for the 6502s, use the same Xover and see how that sounds.

Congrats on the new Center BTW

rskarvan

Are the "old" MW6502's for sale?
I have a set of Monitor 7C's... and, I'd like to replace one of the drivers.

dorokusai

Good info Burdette

burdette

Interesting question about whether a different volume would have made the 6502s sound better. I don't know. Polk doesn't give out T/S parameters, and I don't have the resources to measure them. Thats why from the beginning I tried to duplicate the volume and port of the 8T. I was wondering if the 6510 tends to be ported, and the 6502 is paired with a passive radiator? I haven't scoured the vintage section to answer that question.

Rskarvan,
People on this forum have been very good to me. Russman is always beyond generous, and I have yet to decide how I'm going to give back to HBomb as he gave to me. But, like you, I would have read this thread and thought "gee, I'd like to get one of those drivers for a good price." This is my first opportunity to give back to the guys here.

Absolutely I'll let one of these 6502s go. I really don't think I'll EVER blow one, let-alone two. I have two pairs of speakers that use 6502s (Monitor 7Cs and Monitor 5jr+). But it could be YEARS before I need two.

Pay it forward. How about.. oh.... $30 shipped? They have the usual little specks of "stuff" stuck to the sticky cone, and the labels on the back are gone because I had attached and then removed bucking magnets. And, the foam gaskets around the frame are not original - I didn't get those when I bought them. Both have some residue of the foam insulation I used to seal them tight. Maybe you can salvage the gasket from the driver you remove. HBomb can check out the driver for you before you pay if that would make you feel better.

Just let me know.

HBombToo

Originally posted by burdette



HBomb can check out the driver for you before you pay if that would make you feel better.

Just let me know.

Rskarvan, I don't think it is necessary for me to check the drivers because Mark is way smarter than me on all this. I will state that I have absolute faith that you will be beyond satisfied while dealing with Mark.

Mark, I'm glad you put the speakers to use. I always suspected 1 of the tweaters may have been a little edgy but I am not a good judge. I'm looking forward to a good listen to your center. Polkzilla sounded damn good to me as was and I am very curious about its peformance now.

HBomb

rskarvan

Thanks for your offer.
I hope you don't take offense... but, $30 for a used driver
seems high when a new one from Polk can be had for $45.
Its not that the used driver isn't 100% ok... its just that its
not new and has already experienced 10+years of wear-n-tear.

Personally, I would have priced a used driver at about 25% of the
price of a new one - that would seem fair. The life of the used one is already half gone (estimated)... so, $22 would be about right. But, it is used and there is risk involved (example: shipping damage) in buying a used component. So, $10 to $15 would have been about right.

Anyway, I'll call Polk soon.

Best regards.

- Ron

burdette

You appear to want a deal even better than I would have wanted. There are old SL2000s that looked dented that are being offered for $20 plus shipping. If you aren't comfortable with the prices offered, that is of course your choice.

I'll let one of these 6502s go.. old, used, for $25 shipped.. to anyone that wants it. Any less than that, and it is worth it to me to have this in reserve for my own stuff.

If ANYONE is interested, let me know. If not, then I'll rest comfy knowing I can blow two drivers rather than just one.