2 x10' & B string

[Charla]

When I got a new 2 x 12 cab I decided to sell the 1 x 15 and make my Ashdown Compact 2 x 10 into a light weight 4 Ohm cab for practice and small gigs; I put 2 Eminence Deltalights into the cab and thought everything was fine. I have been using the Cab with my Ashdown ABM 500 head with a 4 string bass. However, for the past couple of practices with another Band I took my 5 string Jazz. During the second practice I noticed the speaker making a noise when I played below bottom E, which sounded like something vibrating against the cone. Resting your finger against a moving cone gives a similar sound!. My question is have I damaged the speakers or is it just that they can't cope with the low B?


Cheers

Charla

[Hamster]

The speakers have to be carefully matched to the cab for them to work properly (which Ashdown probably didn't bother doing when they designed & built it with the speakers they put in it) Just putting in a pair of Deltalights was, imho a waste of money as the chances of them being matched to the cab dimensions are minimal. Alex might go into this in a bit more detail, but that's basically it.

[Mr. Foxen]

The port tuning of that cab is probably too high for those speakers and the low note is pushing them too far. Try making the port tubes longer with rolled card or something, this will lower the tuning and the lows will roll off rather than farting out the speakers. They still won't be bottomy sounding though.

[JTUK]

I don't think it is the speakers asd I have them in my Goliath 2x10 and they are fine.
It isn't the speakers hitting the front mesh panel is it..? as in they are travelling too far..?

[josh3184]

but as other people are saying, just because they work in your cab doesn't mean they'll work in the OP's

[Charla]

Thanks for the feedback: Tried the cab this morning with Ashdown ABM and 4 string Wal; I think I'm pushing the drivers too hard, the cab sounds really good, nice tight sound, then when at volume (about half way on the master volume) the speaker starts to misbehave. I can't tune the ports as this is a vented cab design. So it looks as if it's a `quiet Gigs only' setup, I can't put the old speakers back as I gave one away, and I'm not prepared to try other speakers just yet. Never mind I've always got the the EBS TD650 and Dr Bass 2460!!! Just waiting for a Gig where I can use both cabs together!!!!!!


Cheers

Charla

[Mr. Foxen]

[quote name='Charla' post='772552' date='Mar 12 2010, 10:48 AM']I can't tune the ports as this is a vented cab design.[/quote]

Ported/vented is the same. Do you mean it is a slot rather than a tube? Principle is the same, just need to make it longer.

[spiritchaser]

[quote name='Charla' post='772552' date='Mar 12 2010, 11:48 AM']Thanks for the feedback: Tried the cab this morning with Ashdown ABM and 4 string Wal; I think I'm pushing the drivers too hard, the cab sounds really good, nice tight sound, then when at volume (about half way on the master volume) the speaker starts to misbehave. I can't tune the ports as this is a vented cab design. So it looks as if it's a `quiet Gigs only' setup, I can't put the old speakers back as I gave one away, and I'm not prepared to try other speakers just yet. Never mind I've always got the the EBS TD650 and Dr Bass 2460!!! Just waiting for a Gig where I can use both cabs together!!!!!!


Cheers

Charla[/quote]

Hi Charla,

if you can try out a Glockenklang Soul Combo Light featuring two 10" Volt Speakers (400watts at 4 ohms) do so - they really deliver the low B of my Wals.

tc
Oliver

Edited March 12, 2010 by spiritchaser

[Charla]

Just a thought, would insulating the cabinet make any difference; it's an Ashdown 2 x 10 compact and has no insulation at present?


Oliver

I'd love to try a Glock, I've only heard good things about them; if anyone in the North East of England has one I'd like to hear it?


Cheers

Charla

[Mr. Foxen]

[quote name='Charla' post='772879' date='Mar 12 2010, 03:43 PM']Just a thought, would insulating the cabinet make any difference; it's an Ashdown 2 x 10 compact and has no insulation at present?[/quote]

Stuffing with insulation helps a sealed cab in the mids I think, if it is a ported cab, then lining with knobbly foam is the way, to break up reflections inside.

[alexclaber]

[quote name='Charla' post='772552' date='Mar 12 2010, 10:48 AM']I think I'm pushing the drivers too hard, the cab sounds really good, nice tight sound, then when at volume (about half way on the master volume) the speaker starts to misbehave.[/quote]

I think you're quite right. Only so much possible from a pair of 2510-IIs. Cab size/porting tweakery will get a bit more but not all that much.

[Charla]

Alex

Thanks for the comment; I'm not sure what I can do with the port as it's a vent at the bottom of the cab. Would I be wasting my time insulating the cab and what would be best to use? The cab is a `back up' for small gigs or adding to my 2 x 12, but I would like to make it better without wasting money. Would using different speakers be an advanatge?


Cheers

Charla

[Phil Starr]

Once you reach a certain point it is worth cutting your losses. I wouldn't just buy more speakers on the off chance that they might match the cab, either build a cab to match your drive units, put the old speakers back (I know that you would need to buy one new speaker.

Alternatively adapt your cab to match your Deltalites. One way of doing this is to turn it into an infinite baffle (sealed cab) by closing off the port. This would load your speaker and probably stop the over excursion which you seem to be having. For optimum damping/frequency response(Qtc=0.7) you need a cab of 60litres and with a small bass hump Q=1.1) a cab of about 30litres will do. If your cab is between these two figures then try sealing off the port with a piece of timber (make it airtight). The bass will probably be lighter and 'faster' but it should cure the problem and this cab will respond well to a little bass boost.

Alternatively seal off the port and then make a new port, probably on the back panel, to tune your cab to the Deltalites. Someone will calculate the port dimensions for you if you tell us the internal dimensions of the cab.

[Charla]

Thanks for the support, I'm beginning to regret giving away one of the speakers; that's life. The otherwise cab sounds good!! I will probably give it up as a bad job and use it for low volume rehearsals only; it's starting to get a bit technical for me. I it may be worth thinking about selling the cab and speakers separately to someone who'll use them. I have a lightweight 2x12, which should meet my needs until I grow too old to lift even that, and then have two smaller cabinets again!!!!!


Cheers

Charla

[chris_b]

[quote name='Charla' post='771273' date='Mar 11 2010, 09:27 AM']....During the second practice I noticed the speaker making a noise when I played below bottom E, which sounded like something vibrating against the cone....[/quote]
Go back to the start.... maybe something really is vibrating against the cone. Have you checked that the wiring inside is tucked out of the way? Did you cause any damage to the connectors on the speaker when you installed them? Are all the screws holding the drivers in as tight as they should be? Have you blown a speaker?

[alexclaber]

Chris makes a good point there, especially if the noise is just coming from one woofer. If you want to check the port tuning, lay the cab on its back, put a few grains of salt on one of the cones and sweep a sinewave through it until you reach the point of least vibration. It'll be somewhere between 30 and 80Hz. Post what you find and a tuning tweak can then be suggested. Insulation is always a good thing in speaker cabs - makes the midrange and treble much smoother and clearer due to damping out of phase reflections.

I doubt you'd have much success making it a sealed cab as you'll lose so much bottom and then have to EQ that back in and get premature farting. But if you want to try it, try blocking the vent with lots of socks so it's airtight.

You should expect the cab to perform better with the DeltaLites than with the original (Sica?) drivers, so if it's not measuring up then something is wrong.

[Phil Starr]

Don't knock the infinite baffle. Yes the cab will start to roll off a little higher and you'll lose 3dB at resonance but the sealed cab will roll off at 12dB/octave much slower than the 24dB/octave of the reflex and so at real lows there will be a little more output. (I might model this later if I get time) in addition you'll get better control of transients and excursion will be limited at subsonic frequencies.

What I assume is happening is that the Deltalites resonance is 53Hz, slightly higher than bottom E and a fair bit higher than B which is apparently causing your problems. In addition your cab won't be properly tuned. There is little resistance to the excessive movement of the poor deltalite's cones at frequencies below50Hz and they are 'hitting the stops' Sealing the cabs will limit this and in a gig situation you will probably not notice the changes to the frequency response. I've been experimenting with this recently and although you can measure the frequency response changes and you can just hear them when you play unaccompanied in a gig it just isn't noticeable. Using socks to block the port is a great idea, you've nothing to lose and if it works you can make a permanent seal later.

[bassace]

Just a thought. Have you tried backing off your gain and/or bass and turning up the volume to compensate? I haven't played BG for ages but this worked for me with a DB when I seemed to overload a 10".

[Charla]

Thanks again for the advice; I've had a bit of time to look at the cabinet and it's only one speaker making the noise!! So I must have damaged it, possibly when using the EBS td650 and Marcus Miller 5 string at a rehearsal!!!!!

I originally planned to use the 2x10 and Ashdown amp with my 4 string basses for quiet gigs. Lesson learnt I think; not sure whether to replace the speaker with another deltalite or try and get another Ashdown blue line to go with the one original that's I have left.

Thanks again.


Charla

[Phil Starr]

I'd restore the speaker to original which will leave you with a deltalite to play with or sell on ebay. You could always build a cab for it if you are handy. We could give you dimensions.

[Charla]

Phil

I think I'll do that; could I use the deltalight (8ohms) with the blueline (16ohms) until i get another blueline?

I have an old Torque 1 x12 monitor, which I was going to restore and was thinking I might be able to use the deltalight in that?

Although a diagram for a 1 x 10 cabinet would be handy; I'm not a DIY man, but my best mate is!!!!


Cheers

Charla

[Phil Starr]

If you use the delta with the blueline then the delta will take most of the power and produce most of the sound. Treat the cab as a 300W cab.

The deltalite needs a sealed cab with an internal volume of 8.959l for best power handling/efficiency but with a bass hump and rougher transients or 29.96l for the smoothest bass response anywhere between these will work. If you want to go vented then it needs 42l of air in the cab and you can tune the cab with a 10cm port 12.7 cm long or a 6.3cm dia port (downpipe used in your gutters) 3.33cm long. These give rough tunings which usually sound ok but you will do better if tou can access a signal generator and use Alex Claber's salt method to tune, Add 3l or so to these volumes to allow for the volume of the speaker and any bracing or battens you use.

Cheers Phil