wharfedale diamond 10.4

[GoranB]

I have wharfedale diamond 10.4 (2.5 way passive crossover).
I would like to make an active crossover but im very confused of meaning of two and a half crossover. Could i build 3 way active crossover and use it with these speakers?

Original crossover diamond 10.4 - bass 40-140Hz, midd-bass 140-3800Hz, highs above 3800Hz.

cut off frequency for bass 6dB
midd-bass 12dB
highs-12dB

Another problem is gain of power amplifiers. For midd-bass and highs i would like to use SE power follower 99. This design doesnt have gain so im using tube preamp with gain 30.
For low frequency 20-140Hz i will use Marantz PM 44 SE. I dont know the gain of this amp. If there is possibility to measure gain? Or to change the gain by changeing the components on circuit board of that amplifier. I dont want to use volume control to change gain.

[tcpip]

Originally Posted by GoranB

I have wharfedale diamond 10.4 (2.5 way passive crossover).
I would like to make an active crossover but im very confused of meaning of two and a half crossover. Could i build 3 way active crossover and use it with these speakers?

Original crossover diamond 10.4 - bass 40-140Hz, midd-bass 140-3800Hz, highs above 3800Hz.

If it's a 2.5-way, then the bass and midbass units will overlap in frequency. It's highly likely that the bass unit will go from the bottom to 140Hz as you say, but the midbass unit will also go from the bottom to 3.8K. The two drivers will both generate sound in the region below 140Hz.

I have the Wharfedale Pacific Pi-40 speakers, bought about a decade back. The Atlantic, and then the Pacific range pre-date the Diamond range. The Pi40 is a 2.5-way floorstander. In this speaker, they have done something unusual with the midbass and bass drivers. They have coupled both the midbass and bass units in parallel electrically, thus feeding exactly the same signal to both. The midbass unit is mounted on a sealed, smallish chamber, thus rolling off at a certain frequency. The bass unit is mounted on a large BR enclosure, thus allowing it to operate till the bottom of the frequency range. This means that both drivers reproduce sound in the mid region, and only one driver works in the low bass region. This is totally counter-intuitive --- everything I know about 2.5-way speakers indicates that it should have been the opposite. So, I have decided that I don't understand how the Pi40 works.

cut off frequency for bass 6dB
midd-bass 12dB
highs-12dB

How did you get these figures? I doubt Wharfedale publishes slopes. Couldn't find any such data on their Website.

Another problem is gain of power amplifiers. For midd-bass and highs i would like to use SE power follower 99.

Unless you are willing to remove the drivers, reach inside the enclosure and try to pull out the crossover from within the enclosure, you will have to live with whatever is inside. You will just have access to the bi-amping terminal at the back of the speaker. In that case, (i) you won't be able to bypass their crossover, and (ii) you won't be able to feed separate signals to the midbass and bass units .. they are coupled to the same bi-amp terminal.

I am curious -- how do you propose to replace the existing internal crossover? Will you cut open the enclosure?

[gormish123]

Does anyone have the specs for the Eton 8-480/32 Hex ? Thanks Mike

[GoranB]

Thanks for your reply TCPIP

The specifics are written in user manual. For diamond - 10.4 (140Hz/3.8KHz).
I already opened them from the side of drivers. The crossover is under the bass driver. I have to admit that cabinets are build really great.

You are right that bass and mid bass works together. Its not a problem to took out the crossover. I think ill build a 2way crossower, cut off 3.8Khz. Ill connect the mid-bass and bass driver directly to amplifier, but for bass driver ill use the choke which already exist there. The tweeter will be also connectec directly to amp. In future ill build another power amp for bass driver.

I have tried bi-amping with existing passive crossover but im not satisfied. Somehow i dont see too much advantages with passive bi-amping.

My present setup is modified marantz cd-40, tube preamp, and power folower 99 by Andrea Ciuffoli (this is single ended design - A class. current 3A by channel). Im very pleased with this amplifier, if i can call it like that, because there is no gain. The best mids and highs region i have ever heard. No matter of speakers this amp sounds great. Before i move in Poland I had B&W 602S3 and i was using the same amp. The sound was great also.

Ill try to search on net spec for your PI-40

[GoranB]

TCPIP try here

Audio Manuals and Service Manual Guides | ManualsOnline.com

[GoranB]

About you PI40 i think is the sam situation like in diamond 10.4

There must be a crossover for mid bass drivers. But the driver which is mounted in bigger enclosure goes at lower frequencies becouse of bigger enclosure. In your case is even better then in mine. Becouse you can build (if you are in that) the 2way active crossower and connect the 2 drivers together. It will work for sure but with better damping responce. Try the link ive send it to you. And if you need a help with building active crossover ill be glad to help you.

[GoranB]

About Eton 8-480/32 HEX

Gormish123 send some more informations about speakers you have, maybe even a picture. Ill try to look for specifics.

[tcpip]

Originally Posted by GoranB

The specifics are written in user manual. For diamond - 10.4 (140Hz/3.8KHz).

My question was specifically about the slopes -- how did you know the slopes of the crossover filters? That's not mentioned in the manual.

You are right that bass and mid bass works together. Its not a problem to took out the crossover. I think ill build a 2way crossower, cut off 3.8Khz...

Hope it all works out.

Ill try to search on net spec for your PI-40

Actually, I'm really grateful for your help, but I have no intention of modifying the Pi40. I think they are not worth putting time and energy into -- the enclosures are light and poor quality. (And this used to be their top-of-the-line model in 1999 - 2000.) I think it'll be quite easy to build something much better than those Pi40's.

[GoranB]

TCPIP

About slopes,

I saw the crossover, for bass is one choke only, for mid-bass L to driver and C to GND, for highs C to driver and L to GND. As i know (maybe im wrong) its:

6dB bass
12dB mid-bass
12dB tweeter

To be honest im not sure in this.

But if i decide to use 12db act. crossover i dont see any problem with slopes, it could be just better.
Maybe im missing something in all this, but its worth to try.

Anyway, first ill test one speaker with active crossover and the oder one with passive. If all is fine they should sound similar. I know this is not the best way for testing, but in the other hand i can always put the original crossovers back.

You said your speakers are not worth for active system, i have to say i dont agree, for sure they'll play better in the mid-bass region.

[tcpip]

Originally Posted by GoranB

About slopes,

I saw the crossover, for bass is one choke only, for mid-bass L to driver and C to GND, for highs C to driver and L to GND. As i know (maybe im wrong) its:

6dB bass
12dB mid-bass
12dB tweeter

Oh, got it. You're referring to the electrical filter order, not the acoustic.

But if i decide to use 12db act. crossover i dont see any problem with slopes, it could be just better.
Maybe im missing something in all this, but its worth to try.

Even slight changes to the crossover will change the sound. Typically, it'll make the soundstage worse, due to worsening phase coherence among the drivers. Bigger changes will affect the SPL curve, may introduce peaks and troughs.

You said your speakers are not worth for active system, i have to say i dont agree, for sure they'll play better in the mid-bass region.

Thanks, but I'll pass. Any enclosure which fails the knuckle test so miserably is not worth bothering about.