Ushers 8848P's phase plug....know where to Xover?

[License2ILL]

http://www.partsexpress.com/pe/showd...number=296-604

Anyone know if these can be crossed at 3K? optimally or fairly optimally?

This guy says 8945p's have a dip @1200....anyone know if 8848p's suffer from the same?

http://www.geocities.com/woove99/Spk...Usher_2way.htm

[sdclc126]

Probably not a good point to crossover - right in the middle of a nasty area - lower is recommended.

http://www.partsexpress.com/pdf/296-604.pdf

[License2ILL]

You picking that up from the 2nd graph?
Cuz the first graph seems ok.

Don't know how the 2nd graph works.

How bad would it sound until I upgrade my crossover I guess?
And prolly tweeters as well later.

How low would I have to go? cuz 1Khz or 1.5Khz seems to me like ridiculously low. I dont think bringing a tweeter down to 1200hz should be considered a solution for any speakers....but I guess it must be tuff to find a good spectrum'd set of speakers.

[sdclc126]

2nd graph - shows a peak in the area you want to cross.

Where you cross also depends on the tweeter you use - many can be crossed below 2k - I use the SEAS 27TBFC/G - Zaph has crossed it as low as 1450 Hz on his BAMTM.

Below 2k is a good place to start - doesn't have to be 1000, 1200, 1500 etc. - maybe 1900. The closer you get to the peak the steeper the filter will need to be, and a notch might be called for also.

Jay_WJ has experience with the 8945p - he may have some input on this and may even model a crossover for you if you let him know what tweeter you intend to use, or just follow his recommendations.

http://www.geocities.com/woove99/Spkrbldg/

[License2ILL]

Are you talking about the peak showing to be hitting 95 DB range going up?

Isn't that a good thing? (to me the newb it seems like it just achieves higher volumes there)

by 2nd Graph I mean the one that has 3 lines plotted with some points in between.

this is my current tweeter..plz dont laff it's temporary.

http://digitechstop.com/index.php?ma...oducts_id=3579

Don't things still need to be felt up to like 2000hz?
A tweeter being brought down can't deliver that range properly can it?

[sdclc126]

I extracted the graphs from the site - you want to look at the top one - this is frequency response and impedence; the second graph is a distortion plot.

The orange line is frequency response, the green is impedence. Notice the rising response from about 1500 Hz to 2400 Hz - this, and the ragged area above it, are the where you want to stay out of, thus the lower recommended crossover point and steep filter slope.

I'm not familiar with your tweeter but I can all but guarantee it is a serious mismatch to the Usher. I would highly recommend that if you're going to do a build with the Usher, which is a very high end driver and a good choice, that you consider one of the tweeters in Jay's designs, or at least something in their league.

Here is another site that will be very educational for you:

www.zaphaudio.com

[License2ILL]

Most definitely.....those tweeters are temporary garbage for the time being sorta to limp me by.

I agree for what I paid for them they can't possibly be a good match.

I'm on a budget...im stretching to go with the Ushers as is.
Just wanted to have something that can deliver good precsence and clarity but still go deep...since Im not going with a seperate sub.

I guess I will have to replace the tweeters and crossovers at a later stage. I would still need to buy 2 more Usher's at this point for the other speaker box. But for now I am going only with 1 pair.

That is one awesome link!!!!!!!!!!!!

[sdclc126]

If you're not going to use a sub the little Ushers will be really challenged. Consider this design by Jay as an alternative:

http://www.geocities.com/woove99/Spk...RS180_2way.htm

Vented 7" woofers will give you much greater bass extension, and the Daytons are considerably cheaper than the Ushers. They are a notch below the Ushers but still an extremely high performing and high value driver - I am currently running the 6" Daytons with the SEAS 27TBFC/G tweeters, one of Jay's designs he did for me, and I can attest to their quality. I purchased the Usher 8945ps on Jay's recommendation and will soon be replacing the Daytons.

If you go this route you can put the money you save into good tweeters and the crossover components - you want to build the crossovers exactly as designed.

Think about it - there is no way you will be disappointed at the sound - you can save your money and move up to the Ushers (8945ps) later. Yes get started in this hobby but do a good design your first time out, otherwise you'll be dissatisfied and frustrated and won't be able to afford to fix your problems.

Yes Zaph's site is great - I've gotten a huge chunk of my education from him.

[License2ILL]

My pair of boxes are 1.94 cu. with passive rad. + Xover @ 3000 each currently.

Daytons don't ride that high either.
Want as much low end as I can cuz im a bass head but want to also clear up the muddy midrange and clarity this box needs.

what do u think of:

http://www.partsexpress.com/pdf/297-308.pdf

I was interested in the ushers cuz they fit the box perfectly even tho they're bigger than current 6.5's . Plus the ushers go down low as well.

How much are the tweeters that would need to match the Ushers? and how much to build the crossover for it? What do you think of sound from this match up even tho we're pulling a tweeter down to cover it's "fault"?.... sound like a lot to do for a "faulty" speaker....even more so if they don't end up sounding freakn magnificent.

I know you mentioned beginners stuff and entry level.....but that stage never lasts long with me...before I get hungry for more.... I lack some knowledge but I can hang w/ some guidance when I'm a "newb" at something. But I do go straight to mid-level and or advanced as a routine on things.....cuz I detest doing things twice for lack of knowledge....hence me coming here...and or the internet.

Slowly re-building these speakers around a pair of newly added Usher's is not outside the realm of possibilities...and I think may prove more satisfying when completed...Than having to revisit them later...I would rather do 1 speaker at a time if anything.
Which is what I'm considering.

[sdclc126]

The Vifa woofer is a good choice considering what you intend to work with - it is much better behaved in the region you want to cross over. It is also an overall excellent driver and should give you some decent low end. Both the Dayton and Usher would be a step up, but are not as compatible with your limitations.

It looks as though you intend to use a stock crossover rather than build one more appropriate to particular drivers, at least to start - that's ok for a first build but far from ideal; the Vifa would be the more practical choice here. The cost of building proper crossovers, depending on components, might set you back between $50 and $100 for two speakers for an Usher or Dayton design - IMO a very reasonable, and necessary, part of the overall budget. Again I would rather see you spend a little less on drivers going in and use that saved money for crossover components.

I'm a little concerned that you intend to use a passive radiator with a midbass driver - this is unusual and the results are completely unpredicatble without some measurements. I'd rather see you replace them with small subwoofers - you'd have strong bass without a separate sub and you have enough room in your cabinets to work with. You will want to completely seal off the woofers from the mid-tweet section. This would also allow you to use smaller mids - the Ushers being your first choice.

For tweeter prices look at the Madisound links in Jay's site - the SEAS tweeters start around the mid-high $30s and the Peerless is in the $70s - all reasonable and affordable given their performance. Again my tweeter is the SEAS 27TBFC/G - a tad under $40 and one of the best tweeters at any price - the detail and clarity they produce is amazing.

As for "pulling the tweeter down" to cover the "faults" of the Ushers, Daytons, etc. - these tweeters can do this without issue and there are zillions of 2-way designs out there with these types of crossover points - it's more the rule these days rather than the exception. Just look at the response graphs on Jay's and Zaph's designs - there is no problem - it's largely a matter of proper crossover design, something I cannot overemphasize.

If this sort of thing had issues these guys would not be doing these designs.