crossover design advice

[robbyho]

I'm doing a DIY setup in a Chysler 300 SRT and my client insists on passive crossovers. I've built plenty, but never to the extent that he is asking for. He listens to classical almost exclusively and unfortunately has succumb to a lot of audio myths that I've had to clarify for him.

The tweeter will be in stock location in the corner of the dash, the mid will be in the stock location in the front bottom of the doors, and the subs will be in both corners of the trunk behind the wheelwells.

Tweeter: MDT 44 http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=277-042&scqty=2

Mid: Dynavox LW600 http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=295-605&scqty=2

Subs: pair 10" Dayton H.O.

Front amp is an older soundstream 4 channel (possibly bridged into the passives or a separate channel with each speaker having it's own passive).

Sub amp: MA Audio HK898 300x2 rms
http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=267-122&scqty=1

I told him I would make the best crossover I could, and would tinker with it as much as possible to get the best possible sound.

Any suggestions regarding this? I was thinking of starting with an 12 db/oct active crossover that I have to get a starting point and then build and tweak from there.

From the responses, it looks like both drivers are very linear from 2K-5K, so I expect a crossover point around 2500-3000hz to work best. I only have 2 days to do the install and I'll have to order all the parts tomorrow, so your thoughts are appreciated.

Rob

[robbyho]

If there are any PE 10" subs that will handle classical better, feel free to suggest them. Would the H.F.'s perform better in 0.6 cu ft than the H.O.'s?

Rob

[B&K]

I'd measure the drivers and then install them active, pick your tuning points by ear and build a passive crossover to match.

[khail19]

Sub amp: MA Audio HK898 300x2 rms
http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=267-122&scqty=1


All of the equipment was so nice until I read this. :confused:

[robbyho]

All of the equipment was so nice until I read this. :confused:


The amp is fine. It will be more power than he wants and MA audio is not as bad as some people think.

I would try to get something else, but I have nothing locally and pe is the only place that I can count on for 2 day shipping - it is sort of rush ordering.

Rob

[evan]

I'd measure the drivers and then install them active, pick your tuning points by ear and build a passive crossover to match.
Sounds like a good suggestion to me, especially if you already have a separate electronic crossover to play with.

If the guy doesn't want to listen to reason I'd be tempted to throw a couple of these in and call it done. http://www.partsexpress.com/pe/pshowdetl.cfm?&Partnumber=260-142

[robbyho]

Sounds like a good suggestion to me, especially if you already have a separate electronic crossover to play with.

If the guy doesn't want to listen to reason I'd be tempted to throw a couple of these in and call it done. http://www.partsexpress.com/pe/pshowdetl.cfm?&Partnumber=260-142

lol, I do want to keep him as a customer....

My active x-over only goes down to 3K for the tweets, so I'll have to work around that.

Rob

[quality_sound]

why don't you just run it active and TELL him it's passive.

[Lothar34]

Do it active, and then just solder some stuff to a PCB and stick it in there and tell him it's a crossover.

EDIT:
Didn't read the post above mine :rolleyes:

[npdang]

I wouldn't approach the design without measurement software. At the least you will need individual frequency response for each driver.

[MarkZ]

I told him I would make the best crossover I could, and would tinker with it as much as possible to get the best possible sound.

Can't really tinker much with passive crossovers, unless you mean tear it down and start over each time. That's why active xovers are the superior option. But yeah, I can understand where you're coming from with the stubborn customer.

[robbyho]

Can't really tinker much with passive crossovers, unless you mean tear it down and start over each time. That's why active xovers are the superior option. But yeah, I can understand where you're coming from with the stubborn customer.[/font]

basically - that is the plan. I just have to order enough parts today so I hope that the posted specs are close to real world - I assume they are based on the caliber of equipment, but we'll see.

Rob

[MiniVanMan]

Here's my suggestion. 12 db low pass on the midbass at about 2300 hz and 18 db high pass for the tweets at about 2400 hz. Put in your Zobel, and use a PE adjustable L-Pad. That's my opinion based on my experience with the Morel tweets. I suggest the 18 db for the tweeter for phase/polarity reasons. You can swap phases on the tweets without as dramatic a difference as a 12 db would create.

It won't be perfect, but it should sound pretty good.

[robbyho]

Here's my suggestion. 12 db low pass on the midbass at about 2300 hz and 18 db high pass for the tweets at about 2400 hz. Put in your Zobel, and use a PE adjustable L-Pad. That's my opinion based on my experience with the Morel tweets. I suggest the 18 db for the tweeter for phase/polarity reasons. You can swap phases on the tweets without as dramatic a difference as a 12 db would create.

It won't be perfect, but it should sound pretty good.

That is almost exactly what I was thinking as well. Except w/o the adjustable L pad I will just swap resistors.

I ordered everything today, so I'll post pics up after xmas with the install. Should be rather nice.

Rob

[Patrick Bateman]

I told him I would make the best crossover I could, and would tinker with it as much as possible to get the best possible sound.

Any suggestions regarding this? I was thinking of starting with an 12 db/oct active crossover that I have to get a starting point and then build and tweak from there.

From the responses, it looks like both drivers are very linear from 2K-5K, so I expect a crossover point around 2500-3000hz to work best. I only have 2 days to do the install and I'll have to order all the parts tomorrow, so your thoughts are appreciated.

Rob

All my projects are passive too. I like the flexibility of tweaking slopes and levels.

My secret is to keep a TON of small xover values in a box. So when I need a 6uf cap, I use four 1.5uf caps in parallel. By going this route, I can tweak the value by adding or subtracting caps.

Once I get the value right, I go and purchase the optimum cap.

The same trick works for inductors and resistors of course. Except you put the inductors in series, instead of parallel.

Of course, you need a mic and software to get anywhere fast. Making crossovers by ear is a recipe for madness.

:: PB ::