BSM 4554 ferrite

Someone can tell me something about BSM 4554 ferrite ?

bmspro.com/4554.846.0.html


"The BMS 4554 - 1.4" compression driver is designed for a wide variety
of applications including budget projects requiring 1.4" driver of high
sonic quality. The 4554 offers all the benefits of the patente BMS
compression driver in a 1.4" format, but at much reduced cost."

It is very cheap ... but it is a good Compression Driver or i will be wasting my money buying that?

Its basically the 1" 4544 in a 1.4" format. I have sold quite a few of the 4544's to forum members so best to ask them. I think they sound very nice indeed, but then again I would say that.

Do you need the 1.4"?

By "reduced cost" they mean in reference to their Co-Axial units.

Tony

Edited by: AJW

AJW wrote:

Do you need the 1.4"?

just bought a huge horn on ebay that mount 1 1/4" compression drivers

1.4" isn't the same as 1 1/4"

uhmmm
I can't find a CD with a throat of 1 1/4"
I searched in jbl product, bms, beyma, ciare, rcf, bms p.audio, radian, eminence, 18sound, b&c if you know a model please tell me.
I dont use the english system of measurement but do you usually measure with 4/10 of inch?

1 1/4" is usually a 1" screw fitting.... or is that 1 3/8"?

Hi

I have used BMS 4554. I had it mounted on a big OS waveguide (350hz loading). Despite the huge waveguide, it sounded best crossed over 1k23Hz or higher. I think the BMS suggesting 1k3Hz x-over is right.

Bms 4555 would be suited better to your horn with some modification. Use half moon shaped file and make your horn throat from 1.4 to 1,5". (35mm to 38mm)

If your horn has threaded 1 3/8 throat, use 1" screw-on adapter and BMS 4550. I used this model also in that same big waveguide (with adaptor) and it could be crossed at 800Hz, without being harsh.

All crossovers used here are/were 24 dB LR type.

Another question is your horn shape. Is it exponential or some kind of constant directivity horn. expo-horns tend to load the driver low end better. (allowing bit lower possible crossover frequency to BMS 4554).

Andy

How much power have you sunk into your OS? Just curious.

Gives a nice sound, doesn't it, proper constant directivity...

Deadbeat wrote: How much power have you sunk into your OS? Just curious.

Gives a nice sound, doesn't it, proper constant directivity...

!Off topic alert!

Acoustic or electrical power? I have chevin A750 for highs. Never have it clipping, 8R or 16R loads. Ears clipping first/too small venues/enough spl[img]smileys/smiley36.gif[/img][img]smileys/smiley36.gif[/img].

Can you explain "loud"? (I've travelled in spain several times. Compared to finland, they surely know loud[img]smileys/smiley11.gif[/img])

With bms 4550-16+OS, Peak sens was 115.2dB/4V at 2k8Hz, descending to 104dB/4V at 18kHz.

With bms 4554-8+OS, Peak sens was 116dB/2,83V at 3k3Hz, but no sweet hi end as with 4550, more spl at hi end & ragged hi response[img]smileys/smiley19.gif[/img]. Harsh when crossed lower.

I think about after 120dBs, BMS 454x/455x family has given all what it's worth as "full range" (That's what I'm after, around 1k up). Too much power compression. Working with bands (drums/guitar) one can play enuff loud while not too harsh.

Never tried them in small horn like 3k-5k up (as tweeters). After quick calc probably not much more.

But hey, who another manufacturer can give you that kind of performance in that price. No worries puttin' better bms drivers in home hifi either.

Few months ago I grabbed "some" cash and bought 2*4594nd. (listened and measured also 4590). Liked 4594 better. After quite experimenting I managed to do good sounding passive X/O being 12dB LP/18dB HP. Never going back one way driver with big horns (wise ass talking now, should see myself after 10 or 20 yrs[img]smileys/smiley17.gif[/img]).

BTW nowdays "full hi range" means to me 500Hz and up [img]smileys/smiley2.gif[/img].

At another post here or speakerplans I think I gave you measures and descriptions of my horns.

OS truly gives one a sweet sound and exact directivity, size is bit big without some foam edge thou...

my two cents worth

Andy