10 replies to this topic

[Bon]

i've found some speakers that would be suitable for the 3 ways i'm building (3 way xover thread) but they have a closed back. are these any good for sound quality or should i stay away from them?

thanks in advance
chris

[ProClass]

Closed back speaker are in effect a speaker and enclosure in one unit.
The manufacture is thinking that the mids you are looking at will be used in a box where a woofer is mounted. EG home speakers.
The air volume behind the cone is either large enough to react with the speaker in IB or inifinte baffle or specificly design as an AS or acoustic suspension enclosure. For use in a car, the added protection and "built-in" enclosure is not such a bad idea. But, the design targets of home audio are very different than that of car audio.
A word of caution with closed back mids. Make sure the bass response of the speaker suits car audio applications. I find closed back mids tend to fail in thelower frequency response range.
Cheers

Edited by ProClass, 30 June 2006 - 07:02 PM.

[Pulse-R]

The Dynaudio MD140/2 is a closed back 3" midrange dome.
Plays smooth and clean with 500Hz 24dB High pass, as for upper, (low pass) - I only use them up to 1.2kHz/24dB, so can't comment above that.

Most tweeters are closed-back design.

[zion187reigneth]

Bon, on Jun 30 2006, 05:45 PM, said:

i've found some speakers that would be suitable for the 3 ways i'm building (3 way xover thread) but they have a closed back. are these any good for sound quality or should i stay away from them?

thanks in advance
chris

i was following a car in traffic last week that had 6 closed back speakers on his back parcel shelf ,,, they were 6" , 3" and a smaller one all pointed towards the front ..........zion

[zion187reigneth]

i just looked at my post and the smiley shaking its head means they looked pox ,,, i dont know anything about closed back speakers,atm.........zion

[~thematt~]

Both the Dyn MD140/2 and the Morel CDM54 are closed back speakers. And IIRC possibly the best (or up there with the best) mids available on the market.

IMO, you dont really NEED them to go that low. So long as the vocals stay in the mid zone, and dont venture to the woofers Im happy. Otherwise I get a lower soundstage (happened with my last pair of 2-ways). Though their top-ends are simply exquisite.

Having a closed back also makes them easier to mount. Cone mids require a sealed enclosure, and that can be quite a challenge for some.

[jasonakafreaky]

sorry to stray off the topic a little...

lets say, if the rear speakers are not of closed back design, would the sub's "air-moving" capacity affect the rears?

and if you have an IB sub and rears on the parcel shelf, they would be sharing the same "so-called enclosure" boot would they not? thus would there be a possibility of the played frequency of the rears cancel out the sub to a certain extent?

also, if u had a vent, connectin the boot to the cabin and you have a sub in the boot and rears on parcel shelf as well? wouldnt the rears b rendered useless?

Edited by jasonakafreaky, 03 July 2006 - 03:58 PM.

[ProClass]

jasonakafreaky, on Jul 3 2006, 03:55 PM, said:

sorry to stray off the topic a little...
lets say, if the rear speakers are not of closed back design, would the sub's "air-moving" capacity affect the rears?

Yes

jasonakafreaky, on Jul 3 2006, 03:55 PM, said:

and if you have an IB sub and rears on the parcel shelf, they would be sharing the same "so-called enclosure" boot would they not? thus would there be a possibility of the played frequency of the rears cancel out the sub to a certain extent?

Yes, if the rears are playing the same freq range which I suspect they are not but cancellation would still happen

jasonakafreaky, on Jul 3 2006, 03:55 PM, said:

also, if u had a vent, connectin the boot to the cabin and you have a sub in the boot and rears on parcel shelf as well? wouldnt the rears b rendered useless?

You wouldn't have a vent because the air volume of your boot is too large to couple with the port in any meaningful way.
Cheers

[jasonakafreaky]

would something like this help the rear speakers? its a foam speaker baffle...

[20Hurtz]

i am pretty sure that that is a closed cell foam and is used for keeping the water away from your speakers in the doors. To stop the cancellation you would have to compeltley isolate the rear wave, foam isn't going to do that.

[ProClass]

XTC cups. Yes very good product for smaller speakers. Larger speakers like 6's or bigger have enough air displacment to really suck in or push out the foam. You could use them and fill the extra space with fiberglass or dacron to keep the breathing of the cup to a minimum.
For larger speakers the cup will act like an enclosure and the size of them is often too small to allow the speaker to play it's predicted response.
Very cool cups and can do much more than just keep water off the cone. Some good and some bad depending on your setup
CHeers